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R. W. J. Steen
Animal Production, Volume 58, pp 209-219;

A 3-year experiment was carried out to compare systems of bull beef production involving continuous housing or pasture grazing from 5 to 10 months of age and to examine the effects of herbage allowance and concentrate supplementation on lifetime performance and carcass quality. Animals were either set-stocked at pasture to maintain nominal sward heights of 7, 9 and 11 cm or were offered grass silage (700 g digestible organic matter per kg dry matter (DM)) supplemented with 1·5 and 3·0 kg barley-based concentrates (183 g crude protein per kg DM) per head daily. Half of the animals grazed at each sward height were given 1·5 kg concentrates per head daily while the remainder received no supplement. A total of 160 continental X Friesian and 48 Friesian calves which were initially 197 kg live weight were used. From 10 months of age until slaughter at about 17 months all animals were given grass silage ad libitum and supplemented with 3·0 (year 1) or 3·75 (years 2 and 3) kg cereal-based concentrates per head daily.Animals which grazed the 9- and 11-cm swards produced carcasses of similar weight to those given silage and 3·0 kg concentrates per day, while those grazing the 6·7-cm swards produced carcasses of similar weight to those given silage supplemented with 1·5 kg concentrates. Reducing sward surface height from 11·0 to 9·3 cm did not affect performance but further reductions to 7·9 (year 1) and 6·7 (years 2 and 3) cm reduced live-weight gain by 0·13 and 0·32 kg/day respectively. Concentrate supplementation did not affect the performance of animals grazing swards which were 7·9 cm or taller but increased live-weight gain by 93 and 193 g/kg concentrates for those grazing the 6·7 cm swards and those receiving silage respectively. Differences in live weight at 10 months of age due to the feeding treatments imposed from 5 to 10 months of age were largely retained until slaughter at 17 months as there was little compensatory growth during the residual period. The treatments did not affect carcass composition when the data were adjusted to a constant carcass weight, or meat quality which was satisfactory for all treatments.
K. Christensen, P. Jensen, J. N. Jørgensen
Animal Production, Volume 58, pp 298-300;

Pigs with inbreeding coefficients, ranging from 0·125 to 0·375 were analysed for effect of inbreeding on daily carcass gain, body length and meat proportion in the carcass. The foundation animals were back crosses of a Landrace boar of his daughters which were Yorkshire Landrace hybrids. The statistical model included effect of sex and slaughter weight in addition to the effect of inbreeding. A statistically significant effect of inbreeding on daily carcass gain was found with a linear decline of 1·6 g for 0·1 increase in inbreeding coefficient. There was no effect of inbreeding on body length and meat proportion. Carcass weight had a highly significant effect on body length and daily carcass gain. Effect of sex was statistically significant for meat proportion only.
E. Charmley, R. E. McQueen, D. M. Veira
Animal Production, Volume 58, pp 221-229;

Three wilted silages (dry matter concentration of approximately 300 g/kg) were prepared from early-bloom lucerne which received no additive (MG-0), or was treated with a mixture of carboxylic salts (Maxgrass) at either 4 (MG-4) or 8 (MG-8) l/t fresh crop. Silages were stored in tower silos. Resulting silages were offered ad libitum to growing Holstein steers without supplementation. Untreated silage (MG-0) exhibited an extensive, predominantly lactic acid fermentation. The nitrogen (N) fraction was highly soluble, relative to the crop at ensiling. Silage fermentation and protein solublization were restricted by Maxgrass application. Maxgrass application reduced aerobic stability of silage removed from the upper third of silos but not of silage from the lower portion of silos. Apparent digestibility showed a quadratic response to level of Maxgrass application (P< 0·05). Voluntary intake was not affected by Maxgrass addition (P > 0·005) but intake of all silages was high (30 g/kg live weight (LW)). There was a positive linear response (P< 0·05) in LW gain to Maxgrass application with gains of 0·74, 0·86 and 0·87 kg/day being achieved in steers given MG-0, MG-4 and MG-8 silages, respectively. Degradability of silage N determined in nylon bags in situ was unaffected by Maxgrass application. However, the immediately degradable N fraction was reduced by Maxgrass application (linear effect, P< 0·001; quadratic effect, P< 0·05). Benefits in animal performance due to Maxgrass application were attributed to improved N composition while restricted carbohydrate fermentation during ensiling was considered to be of secondary importance.
N. F. G. Beck, A. R. Peters, S. P. Williams
Animal Production, Volume 58, pp 243-247;

An investigation was conducted to determine the effects of treatment with the GnRH agonist buserelin on day 12 post mating on the reproductive performance of ewes. There was a non-significant (P > 0·05) increase in nonreturn rate (control 0·76 v. buserelin 0·83) and litter size (control 1·51 v. buserelin 1·77) in three flocks. However, there was a significant (P< 0·05) increase in the number of twin lambs born (control 20 v. buserelin 40) and litter size (control 1·44 v. buserelin 1·68) in the yearling flock. There was no effect of buserelin on oestrous cycle length, although there was a tendency for treated animals to have a longer gestation length and heavier lambs. In a ewe lamb flock there was no effect of buserelin on non-return rate or litter size assessed post slaughter on day 31 of pregnancy. However, ovulation rate tended to be greater in the treated animals, which suggests that buserelin may have induced the formation of accessory corpora lutea. These results indicate that buserelin treatment improves embryo survival and that this effect is particularly evident in yearling ewes.
I. A. Wright, J. R. Jones, T. J. Maxwell, A. J. F. Russel, E. A. Hunter
Animal Production, Volume 58, pp 197-207;

An experiment was conducted to examine the response of three genotypes of beef cows to contrasting levels of nutrition supplied from grazed pasture. Twenty-two Hereford × Friesian (HF), 20 Aberdeen Angus × Friesian (AF) and 24 Welsh Black (WB) spring-calving beef cows with their Charolais-cross calves were used in 4 years consecutively. During the summer grazing period they grazed permanent pasture maintained at either 4 to 5 cm (short) or 7 to 8 cm (tall) sward surface height. Sward height treatment significantly (P< 0·001) affected cow and calf live-weight gain (0·498 v. 0·041 (s.e.d. 0·0405) kg/day and 1·12 v. 0·90 (s.e.d. 0·021) kg/day for cow and calf live-weight gain on the tall and short swards respectively). The live-weight gains of the HF and WB cows were similar, but the AF cows gained less weight on the tall sward and lost weight on the short sward. Calf live-weight gain reflected cow milk yield, with the calves from HF and AF cows having similar live weight gains (1·06 and 1·02 kg/day respectively) and those from WB cows having lower gains (0·95 kg/day; P< 0·001). The effect of sward height on calf live-weight gain was greatest in the WB-born calves because of the lower milk yield from WB cows. Body chemical composition changes of cows were predicted from live weight and body condition score, using prediction equations derived from separate groups of cows which were slaughtered at a range of body compositions for determination of chemical composition. Energy balances, calculated from changes in chemical composition, showed the AF cows to have the lowest energy balances with the WB cows the highest. Calculation of energetic efficiency and land use efficiency of weaned calf production taking account of annual food requirements indicated that the HF cows were most efficient, and the WB cows least efficient. The effect of increasing nutritional environment (as represented by sward height treatment) was such as to increase energetic efficiency for all genotypes, but land use efficiency was increased for HF and AF cows, and decreased for WB cows. These results indicate the factors such as size of cows, milk yield potential and pattern of nutrient partitioning can influence energetic land use efficiency of weaned calf production, and that important interactions between genotype and nutritional environment can occur in different measures of efficiency.
J. de Alba, B. W. Kennedy
Animal Production, Volume 58, pp 159-165;

Records on total of 1746 calvings of principally Milking Criollos and their crosses were collected between 1972 and 1990 at the experiment station of the Mexican Association of Animal Production on the Gulf Coast of Mexico. Traits of interest were 305-day milk yield, days in lactation, number of services per lactation (raised to power 1/2), age at first calving and lifetime milk yield. Data were analysed by restricted maximum likelihood (REML) under an individual animal model based on 584 animals of which 146 were female ancestors and 35 were male ancestors. Heritabilities of 305-day milk and age at first calving were 0·17 and 0·07, respectively, but heritabilities of other traits were close to zero. Genetic trend in the Milking Criollos for 305-day milk was small and not significant (0·76 (s.e. 2·38) kg/year). Of crosses with Criollo sires, those involving Holstein and Canadienne breeding had highest 305-day and lifetime milk yields and those involving Brown Swiss and native Mexican (mostly Oaxaca) had lowest yields. Jersey crosses were intermediate for 305-day yield. The F1 Criollo × Jersey cross had highest lifetime yield, but backcrosses involving Jersey breeding were poor for lifetime milk. Additive breed effects for Jersey and Canadienne, relative to Milking Criollo, were 88 (s.e. 91) and 227 (s.e. 74) kg 305-day milk, respectively. Heterosis was 144 (s.e. 55) kg (11·6%) for 305-day milk, 16–4 (s.e. 9·6) (5·0%) for days in milk, −0·107 (s.e. 0–042) (7·7%) for number of services per lactation raised to power 1/2, −25·6 (s.e. 41·4) days (2•3%) for age at first calving and 1789 (s.e. 664) kg (60·0%) for lifetime milk. A plan was designed to develop a nucleus breeding scheme utilizing multiple ovulation and embryo transfer technology (MOET) for the genetic improvement of the Milking Criollo breed in Mexico.
, J. A. M. van Arendonk
Animal Production, Volume 58, pp 173-180;

Inbreeding leads to reduction of the additive variance, whereas inbreeding depression reduces the performance of milk producing cows in both the nucleus and the commercial population. In this study, the cumulative additive response to 30 years of selection corrected for variance reduction due to inbreeding and inbreeding depression in the commercial cow population (denoted as expected phenotypic level or P) was evaluated in a closed (1024 cows tested per year) dairy cattle nucleus scheme, assuming a large number of gametes available per female. No dominance effects were simulated nor estimated in the nucleus. Various hierarchical and factorial designs with fewer sires than dams, an equal number of sires and dams, or even a larger number of sires than dams were compared for P. The trait considered was overall economic merit for milk production with a heritability of the unselected base population of 0·30. Sires and dams were selected on their animal model estimated additive effect for the trait considered at either 15 or 27 months of age. All full-sibs were available for selection. In the absence of inbreeding depression, a complete factorial scheme with more sires than dams resulted in the highest P. With increasing inbreeding depression, the optimal number of sires increased relatively more than the optimal number of dams. Increasing the number of sires decreased inbreeding relatively more than increasing the number of dams, and resulted in a relatively higher P. This is due to the fact that correlations between estimated additive effects of male selection candidates are higher than between those of female selection candidates.
N. D. Cameron, S. C. Bishop, B. K. Speake, J. Bracken, R. C. Noble
Animal Production, Volume 58, pp 237-242;

Fatty acid synthetase and lipoprotein lipase activities, lipid content of adipose tissue and the fatty acid composition of subcutaneous fat, sampled by biopsy at the 13th rib, were measured in 20-week-old rams from lines of Texel-Oxford (TO) and Scottish Blackface (SB) sheep, both divergently selected for carcass lean content. A total of 150 animals were measured, with close to equal numbers of animals per selection line-breed combination. In both breeds, the high (lean) selection lines had significantly lower backfat depths (TO : 0·5 mm and SB : 0·6 mm, s.e.d. 0·2) than the low (fat) lines. The lipid content of subcutaneous fat was 65 mg lipid per g fat tissue wet weight (s.e.d. 24) greater in TO rams than in SB rams. The TO low line had a higher lipid content than the high selection line (426 v. 448 (s.e.d. 36)) and although the SB selection lines did not differ, the selection line with breed interaction was not significant. SB rams had higher fatty acid synthetase activity (3·1 v. 2·6 (s.e.d. 0·3) on a log scale) but there were no differences between selection lines. Lipoprotein lipase activities were similar between breeds and selection lines. The lower concentration of myristic acid (C14:0) of TO rams compared with SB rams (0·9 (s.e.d. 0·3)) was the only breed or selection line difference which was statistically significant for fatty acid composition of subcutaneous fat. Lipid content of subcutaneous fat and lipoprotein lipase activity were highly correlated and both were positively correlated with performance test traits, especially with backfat depth. The correlation between backfat depth and fatty acid synthetase activity was not different from zero. Performance test traits, lipid content of subcutaneous fat and lipoprotein lipase activity were positively correlated with the unsaturated fatty acids, with the exception of C18 :1 when correlations were negative.
K. H. de Greef, M. W. A. Verstegen, B. Kemp, P. L. van der Togt
Animal Production, Volume 58, pp 263-270;

Many pig growth models assume that there is no effect of energy intake and of body weight on the ratio of lipid to protein deposition rate in pigs below their maximal protein deposition rate. An experiment was performed to check whether an effect of body weight and of amount of energy intake on this partitioning of energy is indeed absent when protein deposition is limited by energy intake. Two constant amounts of energy were given above maintenance requirement (12·6 and 16·3 MJ digestible energy (DE) per day for production, treatment L and H, respectively). A total of 52 entire male pigs were slaughtered at 25,45, 65, 85 or 105 kg live weight. Results showed that, for both levels of intake, the ratio of lipid to protein deposition rate increased with increasing body weight. At the L energy intake, the ratio of lipid to protein deposition rate increased from 0·74 at 25 kg to 0·99 at 105 kg body weight. In animals receiving the H treatment, the ratio of lipid to protein deposition rate increased from 0·82 to 1·35 in that weight range. This change in nutrient partition was also reflected in daily gain. Daily gain declined with increasing live weight, a decrease of 150 g/day over the weight range 25 to 105 kg. The 3·7 MJ DE difference in energy intake between treatment H and L resulted in an average overall difference of 105 g daily gain. A control group fed ad libitum showed that protein deposition capacity was above 200 g/day, thus the pigs at the L and H treatment were below their protein deposition capacity. It was concluded that both live weight and energy intake influence the ratio of lipid to protein deposition rate. The mechanism of partitioning between lipid and protein deposition below maximal protein deposition capacity needs further specification in order to improve the predictions of growth models which use the linear-plateau concept.
M. B. Salawut, S. K. Adedeji, W. H. Hassan
Animal Production, Volume 58, pp 285-289;

Experiments were carried out to establish the suitability of full fat neem seed meal (FFNSM) in broiler and growing rabbit diets. In the broiler experiment, 200-day-old (Babcock) broiler chicks were used in a 10-week trial, with the FFNSM fixed at 0 (control), 25, 50, 75 and 100 g/kg diet. In the rabbit experiment 24 rabbits of three different breeds were used in an 8-week trial, with the FFNSM fixed at 0 (control), 100, 200 and 300 g/kg diet. The criteria of response were food intake, weight gain, food conversion and protein efficiency ratio and mortality. There was a significant (P < 0·05) negative correlation between the dietary inclusion of FFNSM, weight gain and food conversion efficiency of the birds in the starter phase. In the finisher phase from 5 to 10 weeks, food intake, weight gain, food conversion and protein efficiency ratio did not differ significantly (P > 0·05) between the birds on the control diet and diets containing up to 75 g FFNSM per kg. For all the measurements, rabbits on the diet with 100 g FFNSM per kg gave better results than the control. Food intake, weight gain, food conversion efficiency and protein efficiency ratio did not differ significantly (P > 0·05) between rabbits on control diet and the diet containing 200 g FFNSM per kg. Performance on the diet with 300 g FFNSM per kg was poorest.
A. A. El-Darawany
Animal Production, Volume 58, pp 294-297;

The present study was carried out on the pure Bauscat (Bau), pure New Zealand (NZW) and pure Californian (Cal) strains of rabbit. Overall reproductive performance for overdue does of the three breeds was determined and compared with that of does delivering at the normal time. Overdue does of the Bau and NZW breeds had a significantly (P < 0·05) higher annual mean number of pups weaned than overdue Cal does. There was a high incidence of pup mortality in post-mature litters, and the causes of this high mortality were crushing of the skull followed by subsequent stillborn-birth difficulties and intra-uterine death in all three breeds. Obliteration of the anterior fontanelle of pups from post-mature litters occurred in 71%, 75% and 69 % of the deaths diagnosed at birth in the Bau, NZW and Cal breeds, respectively. Induction of parturition with either PGF or oxytocin reduced pup mortality in overdue does. The birth-to-remating interval was significantly (P < 0·01) lower in overdue does in which parturition was induced with PGF2∞ but significantly longer when parturition was induced with oxytocin.
S. Fernández-Rivera, A. Midou, H. Marichatou
Animal Production, Volume 58, pp 249-256;

The influence of food allowance or level of food excess on diet selectivity and intake by sheep given pearl millet stover leaves, and the potential feeding value of the food leftovers (not eaten) (L) were studied. Animals were given food at four levels of L (100, 300, 500 and 700 g dry matter (DM) per day). All sheep received different food allowances (A, g DM per day) and had different L/A and A/M (g DM per kg M) ratios. An additional treatment consisted of feeding the leftovers from the two highest levels of food excess to six rams to have 300 g DM of L per day. A diet supplement was given to provide sufficient rumen degradable protein and sulphur to sustain microbial activity. Variances of organic matter (OM) digestibility (OMD, g/kg) and intake (g/kg M0·75) of both DM (DMI) and digestible OM (DOMI) of the original millet leaves were analysed using L, L/A, A/M and A/M0·75as independent variables. Variation accounted for was highest when OMD was analysed as a function of L/A (R2= 0·34) and when DMI was analysed as a function of A/M (R2= 0·79) or A/M0·75(R2= 0·80). The response in OMD to varying L/A was best described by the equation OMD = 457 (s.e. 16) + 157 (s.e. 48) L/A. As L/A or A/M increased, L had a lower concentration of acid-detergent fibre and a higher in sacco OM disappearance. As A/M increased, DOMI and L/A increased following a diminishing return pattern. However, when A/M fell below 31·1 (s.e. 0·9) g DM per kg M, DOMI decreased linearly. No differences (P> 0·33) were observed for OMD between the original food (505 (s.e. 8) g/kg) and the re-fed leftovers (489 (s.e. 15) g/kg), but DOMI was lower with the latter (22•4 (s.e. 0·4) v. 20·3 (s.e. 0·8) g/kg M0˙75,P< 0·03). Results suggest that DOMI of millet stover should be determined at L/A much higher than the traditionally recommended (0·15), and support the hypothesis that farmers could benefit from feeding millet stover at high allowances to animals of high economic value and give the leftovers to less valuable or less selective stock.
, C. H. Knight
Animal Production, Volume 58, pp 181-187;

Twenty lactating dairy cows were used to investigate the relationship between the site of milk storage in the udder and the short-term response to thrice-daily milking. Cisternal and alveolar milk volumes were measured 8 h after an ordinary morning milking by catheter drainage and machine milking with oxytocin respectively. The response to thrice-daily milking was assessed using a half-udder technique and the relative milk yields quotient (RMYQ). Over the first 7 days, both halves were milked twice daily (8/16 h intervals) and milk yields over the final 4 days of this period were higher for left fore/right hind (LF/RH) (12·4 (s.e. 0·85) kg/day) than for RF/LH (10·5 (s.e. 0·63) kg/day) which was milked after LF/RH throughout the experiment. Over the following week, LF/RH quarters were milked an additional time (8/8/8 h intervals) and yields over the final 4 days were increased (15•7 (s.e. 0·95) kg/day) compared with control quarters (9·8 (s.e. 0·73) kg/day). In a final 4-day period, animals were milked twice daily and half udder yields were 13·1 (s.e. 0·89) kg/day and 10•6 (s.e. 0·77) kg/day respectively. Differences between yields from the two halves of the udders were highly significant in all 3 weeks of the experiment (P< 0·001). Cistern milk yield as a proportion of total milk yield at 8 h (cistern proportion) averaged 0·170 (s.e. = 0·0275; range 0·020 to 0·334) and tended to be greater for multiparous (0·215, s.e. 0·0279) than for primiparous animals (0·118, s.e. 0·0437; P = 0·076). During the periods of twice-daily milking, the proportion of milk yielded from LF/RH quarters was not significantly related to cistern proportion (P = 0·70 and 0·43 for weeks 1 and 3 respectively). However the response to thrice-daily milking, assessed as RMYQ, was significantly related to cistern proportion both when changing up to, and down from, thrice-daily milking (P< 0·01). Animals with low cistern proportions showed larger responses to thrice-daily milking. There was a significant relationship (P< 0·05) between the responses on changing up to, and down from, thrice-daily milking. Primiparous animals tended to exhibit smaller declines on returning to twice-daily milking than multiparous animals with equivalent responses to thrice-daily milking.
A. M. Sibbald, W. G. Kerr
Animal Production, Volume 58, pp 231-235;

To examine the effects of body condition and previous nutrition on the herbage intake of ewes grazing swards of different heights in autumn, 96 Scottish Blackface X Border Leicester ewes with a wide range of body condition (score 1·75 to 3·50), were initially housed and given 50 g dry matter (DM) per kg metabolic live weight (M)0·75 per day (treatment L) or 95 g DM per kg M0·75 per day (treatment H) of a pelleted dried grass diet (11·6 MJ metabolizable energy per kg DM) for 6 weeks after weaning in July. The H ewes gained more live weight (9·0 v. 2·7 kg) and body condition score (0·39 v. 0·17) than the L ewes. Half the animals from each treatment were then allocated to each of two ryegrass pastures with a sward height of 5 cm (LS) or 10 cm (HS) for a further 6-week grazing period. During the grazing period there was no significant effect of indoor feeding level on herbage intake, but the L ewes gained more live weight (6·4 v. 5·0 kg) than the H ewes. On the HS, compared with the LS sward, mean herbage intakes were higher (70·0 v. 60·5 g DM per kg M0·75) as were gains in live weight and condition score (7·9 v. 3·4 kg; 0·18 v. 0·0). There were no interactions between the effects of sward height and previous feeding level on herbage intake. Ewes in low body condition (< 2·5) at the start of the grazing period ingested the same amount of herbage on both swards (70·3 g DM per kg M0·75) whereas ewes in high body condition (> 2·5) ingested more (67·0 v. 51·6 g DM per kg M0·75) on the HS compared with the LS sward. The responses of ewes in low and high body condition to different sward heights are discussed in relation to appetite drive and aspects of grazing behaviour.
A. J. Rook, C. A. Huckle, R. J. Wilkins
Animal Production, Volume 58, pp 167-172;

Forty-eight spring-calving, Holstein-Friesian cows were continuously stocked on perennial ryegrass-white clover swards maintained at compressed sward heights of 4, 6 or 8 cm and offered 0 (U) or 4 (S) kg concentrates. Milk yields and composition, live weights and intakes (estimated by the n-alkane technique) were recorded for periods 24 May to 27 June (P1) and 28 June to 8 August 1992 (P2) with 4 cm swards not used in P2. Milk and component yields were significantly lower at 4 cm than at 6 or 8 cm in P1 and significantly higher when supplements were offered in both periods with no significant interaction. Herbage intakes were reduced more by supplementation at lower sward heights. Live weight was significantly lower on the 4 cm sward. Fat concentrations were unaffected by height and supplementation in P1 but significantly increased by supplementation in P2. These results suggest that maintaining a sward height of 6 cm offers advantages in terms of individual animal output and output per ha compared with grazing at greater or lower sward heights.
P. H. Simmins, S. A. Edwards, H. H. Spechter
Animal Production, Volume 58, pp 271-283;

A 2 X 3 factorial experiment was designed to study the consequences of feeding strategy during rearing and pregnancy over eight parities on sow growth and body condition. Two hundred and fifty-four gilts were group-fed on a restricted scale rising to either 2·25 (L) or 2·70 (H) kg/day (12·5 MJ/kg digestible energy (DE), 193 g/kg crude protein (CP) diet) from 70 to 175 days of age. A total of 156 of the L and H gilts were then given either 1·8 (l), 2·1 (m) or 2·4 (h) kg/day during subsequent pregnancies (12·9 MJ/kg DE; 177 g/kg CP diet). The same diet was offered to a standard scale during lactation. Sows were group-housed in pregnancy and given straw bedding. Losses of sows in rearing and each parity were not associated with treatment. After rearing, data have been presented only for those sows which completed eight parities. At 175 days of age, H gilts had grown faster (P < 0·001). From 175 days to service all gilts were given the same feeding regime but L gilts put on significantly more weight than H gilts, exhibiting more efficient utilization of food. There were no statistically significant differences in weights between L and H sows after the third pregnancy but L sows gained more weight than H sows in most pregnancies. The sows grew in each parity, indicating mature body size was not achieved. The pregnancy regimes had a significant (P < 0·05) effect on live weight, P2 backfat measurement, body length, neck circumference and condition score. Pregnancy treatment h produced the heavier and fatter animals but not all treatment l sows maintained adequate backfat levels for six parities. When housed in groups and given a generous supply of straw, the nutritional requirements of sows to sustain growth and body condition suitable for a long life may be less than has been previously identified for sows housed on concrete and slats without bedding.
F. D. Mellett, J. H. Randall
Animal Production, Volume 58, pp 291-293;

In a study of the growth of various body parts of the ostrich, only the growth of the head could be described with the Gompertz function. The growth of the ostrich head (y in g) with time (x in months) is described by the Gompertz function y = 613 exp[−ln (613/133) exp(−0·26x)]. This information could be used in the design of carcass classification systems.
P. Narain, A. P. Kaur
Animal Production, Volume 58, pp 189-196;

The accuracy of progeny testing for a continuous trait when the auxiliary information was based on ‘all-or-none’ type of traits with a multi-factorial threshold model was examined. The accuracy of the progeny test was found always to increase with the inclusion of the auxiliary trait. It followed the same pattern as in the case of continuous auxiliary trait. However, there was an additional feature in that the accuracy was also dependent on the probability of incidence of the discrete trait unless either the progeny group size was very large, and/or there was no genetic correlation or else the probability of incidence was itself extremely low. Compared with the case when the auxiliary trait was continuous, there was a loss in accuracy which can be looked upon in two ways. First, the continuous auxiliary trait is itself made ‘all-or-none’ type by a threshold and the accuracies compared in the two cases. The loss increases symmetrically in either direction with increase in positive or negative directions of the difference in genotypic and phenotypic correlations. Secondly, a comparison can be made of the accuracy when the auxiliary trait is normally distributed with that when it is binomially distributed but with the same amount of genetic information on the observed scale as given by the heritabilities and genetic correlations. No loss now occurs if the two classes of the binomial trait are equally likely and the loss in accuracy increases with the decrease in the standard deviation of the binomial distribution for given values of other parameters. It was found also that the use of binomial auxiliary trait reduced the number of progeny required to attain a pre-assigned level of accuracy, resulting in a decreased cost of the programme compared with that when no binomial auxiliary trait was used.
M. R. Sanz Sampelayo, I. Prieto, L. Lara, F. Gil Extremera, J. Boza
Animal Production, Volume 58, pp 257-261;

The morphological development of the sheep and the goat is different and this difference is manifested from early post-natal life. The main characteristic of kid goat carcasses is their low adipose tissue, and this is considered detrimental to quality. In an attempt to determine the nutritional causes of this, a study was performed with kid goats of the Granadina breed and lambs of the Segureña breed. Six kid goats and six lambs were slaughtered at birth, while a further eight kids and eight lambs were fed a milk replacer to satiety until the 60th day of life and slaughtered on the 61st day. Dry matter (DM) and metabolizable energy (ME) intakes and apparent digestibility of energy were determined in four balance periods between 8 and 60 days of life. From the intakes of ME and comparative slaughter data it was possible to calculate energy retention (ER), heat loss (HL) and energy retained as protein (ERp) and as fat (ERf) for kids and lambs. Kid goats showed a similar apparent digestibility of energy to lambs but had lower DM and ME intakes per kg metabolic body weight (M0·75) than lambs. For kids and lambs respectively these values were: 0·93 and 0·94; 45·4 and 50·1 g/kg M0·75 per day; 937 and 1033 kJ/kg M0·75 per day. Mean values for ER, HL, ERp and ERf rates were: 263, 674, 131 and 132 kJ/kg M0·75 per day for kid goats and, 343, 690, 132 and 211 kJ/kg M0·75 per day for lambs. Together with the different intake, kid goats showed a lower rate of ER and overall, a lower rate of ERf than lambs.
T. Nolan, J. Connolly
Animal Production, Volume 48, pp 519-533;

The effects of mixed v. mono-grazing by steers and sheep on individual animal growth rate, pasture carrying capacity and live-weight output per ha were measured in a 4-year (1978 to 1981) experiment, after a preliminary familiarization year, 1977. Annual stocking rate treatments consisted of three monosteer, three mono-sheep and seven mixtures of steers and sheep. Annual average stocking rates were 2·11 steers † 8·1 ewes per ha under mixed grazing and, under mono-grazing, 4·44 steers and 15·2 ewes per ha. The range from low to high in stocking rate in mono- or mixed grazing was close to 40%. Over the 4 years a total of about 280 steers, 900 ewes and 1100 lambs were used.Overall, mixed grazing increased average lamb daily live-weight gain (ADG) to weaning and to drafting from 246 to 265 g (P< 0001) and from 211 to 223 g (P< 0·001) respectively. Steer ADG for these periods was increased from 1·419 to 1·520 kg (P< 0·01) and from 0·950 to 1·094 kg (P< 0·001). The choice of reference mono-grazing stocking rates for comparisons of mixed v. mono-grazing ADG can affect these results. Average live-weight outputs (kg/ha) from grazing for the mono-steers, mono-sheep, and mixed grazing were 663, 690 and 714, the range in the latter over the seven mixed grazing treatments being from 605 to 805. Stocking rate was the main factor affecting output per ha. Because of the management rules used in this experiment mixed grazing effects are more appropriately assessed through ADG and measures based on it than on output per unit of area.Models were fitted relating steer and lamb ADG to lamb weaning and lamb and steer drafting to stocking rates of steers and ewes. Mixed grazing benefits to steer and lamb ADG to drafting were greater as their proportion in the mix declined and increased with stocking rate. At the 50% proportion, lamb and steer ADG were improved by 5·2 and 3·4% respectively at low stocking rate and 9·4 and 6·6 at high stocking rate. Predicted steer ADG to lamb weaning for a given steer stocking rate increased with increases in ewe proportion up to five ewes per ha and decreased rapidly with further increments in ewe proportion.Mixed grazing efficiency was also evaluated through the Relative Resource Total. This showed that under mono-grazing 10 to 13% more area was required to produce the same grazing season output as under mixed grazing. The 10% improvement in carrying capacity was exceeded for ewe: steer frequencies ranging from 1·5: 1 to 10: 1. Explanations for this greater efficiency in resource capture/use under mixed grazing are discussed.Substitution rates for lamb ADG to weaning (2·35) and to drafting (2·86) and for steer ADG to drafting (0·21) were fairly constant over the 4 years 1978 to 1981.Selection of mixed stocking rates to suit growth rate targets for different animal types and to match food supply with demand under varying soil/climatic/topographical conditions is discussed.
E. A. Adebowale, E. R. Ørskov, P. M. Hotten
Animal Production, Volume 48, pp 553-559;

The comparative effect of spraying wheat straw, maize stover and maize cob with sodium hydroxide and alkaline (sodium hydroxide treated) hydrogen peroxide over a range of moisture contents was evaluated. The effect of concentration of hydrogen peroxide on straw subsequently ammoniated was also investigated. No differences (P< 0·05) were detected between sodium hydroxide and similar concentrations of sodium hydroxide used to provide alkali for alkaline hydrogen peroxide treatments. When however, gaseous ammonia was used as the source of alkali there were significant linear increases in degradability with increasing concentrations of hydrogen peroxide. At 48 h incubation, degradability values for untreated, ammonia-treated, 10, 50 and 100 g alkaline (ammonia) hydrogen peroxide per kg were 528, 595, 640, 676 and 716 for wheat straw, 618, 652, 683, 717 and 743 for maize stover and 392, 467, 585, 632 and 686 g/kg for maize cob respectively. It is concluded that the use of gaseous ammonia as the source of alkali seems a possible practical method of using hydrogen peroxide to increase degradability of straws.
L. D. Jacobson, S. G. Cornelius, K. A. Jordan
Animal Production, Volume 48, pp 591-599;

A food-driven pig growth model was developed from two existing mathematical models. The new model predicts daily growth and heat production of early-weaned pigs. An existing pig growth model was altered by replacing the environmental component with a heat transfer model. The heat transfer model was further refined by partitioning latent heat loss between the skin and lungs, adding a thermal resistance for hair coat, and increasing tissue thermal resistance. Results from this combined model were compared with experimental observations of daily piglet growth and heat production at 15°C, 20°C, 25°C and 30°C. Good agreement existed between observed data and model predictions for piglet growth. Heat production predictions did not compare as well with experimental observations as did growth, especially when piglets lost weight.
C. J. Newbold, P. C. Thomas, D. G. Chamberlain
Animal Production, Volume 48, pp 611-615;

Sodium bicarbonate had no effect on the dry-matter (DM) intake of heifers given a complete mixed diet of grass silage, molasses, barley, soya-bean meal and a mineral mix (660, 140, 100, 85 and 15 g/kg DM respectively) when it was incorporated into the mix at 20 and 40 g/kg DM or sprinkled on top of the diet at a rate of 350 g/day. In a second experiment, cows in mid lactation were given a complete mixed diet of silage, barley, soya-bean meal and minerals (660, 240, 85 and 15 g/kg DM) or the same diet with the barley replaced with molasses at 140 g/kg DM. Sodium bicarbonate was sprinkled on top of the diets at 0, 450 or 900 g/day. There were no significant effects on DM intake in the final week of each 3-week period. However, there was an apparent interaction of diet and sodium bicarbonate on the initial acceptance of the diet, with the intake of the diet in week 1 being significantly lower than the final intake with 900 g/day sodium bicarbonate in the absence but not in the presence of molasses.
Y. Nakashima, E. R. Ørskov
Animal Production, Volume 48, pp 543-551;

Four experiments were carried out to measure the effects of exposure to a cellulase preparation on the degradation characteristics of whole barley straw and its botanical fractions. The effect of chemical pre-treatment (NaOH and H2O2) on treatment with a cellulase preparation and the addition of propionic acid to inhibit loss of dry matter were also studied during the fermentation of ensiled straws. Samples of each preparation were incubated in polyester bags in the rumens of three sheep to estimate degradability. The data were described using the equationp = a + b (1—ec) where p is degradability at time t and a, b and c are constants.The pH of ensiled straw was consistently decreased (P< 0·01) and the solubility increased (P< 0·01) by treatment with a cellulase preparation and by increasing the period of ensiling. The b values were decreased by increasing the length of the ensiling period (F < 0·01). The increase in the solubility of the treated botanical fractions was particularly apparent for the leaf blades, followed by leaf sheath, with the internodes being least affected (P< 0·01). However, treatment with a cellulase preparation had little or no effect in increasing the potential degradability (a + b) of any botanical fraction. The degradability of the whole plant and botanical fractions of straw increased (P< 0·01) with NaOH treatment and was further improved (P< 0·01) by alkaline H2O2 treatment. The increase was greater in internodes than in leaf sheath (P< 0·01). Treatment with a cellulase preparation and chemical pre-treatment had little or no effect on the 48-h dry-matter loss (DML) and the (a + b) values, but it increased (P< 0·01) the a values and solubility.DML from straw treated with a cellulase preparation during fermentation decreased (P< 0·01) from about 60 to less than 10 g/kg with 30 g propionic acid added per kg straw to inhibit bacterial activity. The decreased fermentation loss was reflected in an increase in the 48-h DML and potential (a + b) values of straw treated with a cellulase preparation.
L. O. Fiems, E. Decuypere, Ch. V. Boucque
Animal Production, Volume 48, pp 601-605;

Investigations were made of the effects of the fi-agonist cimaterol on the growth and hormone status of normal and double-muscled Belgian White-blue bulls. Results indicated that repartitioning effects of this agonist may in part be mediated indirectly through an alteration in the levels of metabolic hormones and that the growth promoting effect is transient.
I. Fadel, J. B. Owen, R. Kassem, H. Juha
Animal Production, Volume 48, pp 606-610;

Milk composition in Awassi sheep was determined in relation to time of milking, stage of lactation and age of ewe. About 80 ewes of the main flock of the Kraim Centre, were used. Fat, total solids and solids not fat proportions were not significantly affected by age of ewe, but they increased as stage of lactation advanced. With equal intervals of milking of 12 h, milk fat and total solids proportions were higher in the evening milk than in the morning milk although no differences between the morning and evening in the quantity of milk obtained were observed.
L. Bodin, J. M. Elsen
Animal Production, Volume 48, pp 535-541;

The assumption that observed values for litter size result from a set of thresholds which impose a discontinuity to the visible expression of a continuous underlying variate has been tested using data from the French sheep recording scheme: 629 724 natural lambings for 32 different pure breeds and 66 379 litters obtained after synchronization treatment in 15 breeds. Frequencies of single, twin, triplet and higher-order births varied regularly with litter size within each fecundation type. The coefficient of variation of litter size was remarkably constant from breed to breed under both natural (0·35 to 0·40) and induced lambings for which it was higher (0·40 to 0·45). The regression of the difference between the first two thresholds of an underlying normally distributed variate on prolificacy was slowly negative for natural fecundation, but not significant for induced fecundation. A significant effect of fecundation type was found, resulting in a lower incidence of induced than of natural twin litters for the same level of prolificacy. Multivariate polynomial regression of frequencies on natural and induced prolificacy was used to predict expected frequencies of litter size and the proportion of lambs of each birth type.
M. N. Sillence, T. D. Etherton
Animal Production, Volume 48, pp 585-589;

There is evidence that the growth of female rats and sheep may be constrained by physiological concentrations of glucocorticoid hormones. This study was designed to examine the effects of trilostane, an inhibitor of adrenal steroidogenesis, on serum cortisol concentrations and growth in pigs.First, trilostane was tested at three doses (250 mg, 500 mg and 1000 mg per pig) to examine its effect on serum cortisol concentrations. A reduction in serum cortisol concentration was observed 2 to 4 h after oral administration of trilostane (P< 0·05) and the adrenal response to a challenge dose of ACTH was reduced 4 to 6 h after administration (P< 0·05), at all doses tested. In a second experiment, trilostane (9·24 mg/kg body weight) was administered orally to 10 pigs twice daily for 35 days to examine its effects on growth rate. A further 10 pigs received a placebo. Trilostane did not affect weight gain or carcass composition, but caused a reduction in food intake (P< 0·05). Adrenal weight was increased by trilostane treatment and liver weight was reduced.These results show that trilostane is effective at lowering serum cortisol concentrations acutely, but suggest that physiological concentrations of glucocorticoid hormones may not retard growth rate in barrows.
M. N. McLeod, B. R. Smith
Animal Production, Volume 48, pp 503-511;

A study was made of the effect of fibre level in forages on eating and rumination behaviour. Eight forage diets were prepared from the leaf and stem fractions of two grasses and two legumes and were given at hourly intervals to four steers under steady-state conditions. Eating and rumination behaviour were measured automatically by recording changes in intra-oesophageal pressure.Mean voluntary intake of leaf was higher than that of the stem fractions (9·9 v. 5·6 kg/day; P< 0·001). This was associated with a shorter mean retention time in the rumen of the leaf than that of the stem fractions (21·4 v. 30·6 h; P< 0·001) and a lower concentration (g/100 g dry matter (DM)) of fibre (52-0 neutral-detergent fibre (NDF) and 30·5 acid-detergent fibre (ADF) v. 68·2 NDF and 45·3 ADF). Similar values (P > 0·05) between diets were found for both the water and DM contents of the rumen (60·1 kg, 7·8 kg). Voluntary intake was not related to either.No difference was found between forage diets in the mean time (132 min) and number (18·7) of periods spent eating each day (P > 0·05). Legume leaf fractions were eaten at a faster rate (g/min) than either the grass leaf or the stem fractions. Voluntary intake was related to the rate at which food was eaten (r = 0·89; P< 0·01) but no relationship was found with the time taken to eat food (r = –0·14; P>0·05). Eating rate was related to the level of both NDF (r = –0·91; P< 0·01) and ADF (r = –0·96; P< 0·001).Differences between diets were found in rumination times (mean 425 min; P< 001), the number of boluses regurgitated during each period (27·6; P< 0·05) and during each day (485; P< 0·001), and in the weight of boluses (455 g; P< 0·05). No differences (P > 0·05) were found between diets in the mean number of rumination periods each day (17·6), the mean time spent ruminating during each period (24·3 min), the mean rate at which boluses were regurgitated (53·2 s per bolus), the interval between boluses (5·1 s), and the DM in a bolus (27·5 g). Rumination time and the number of boluses regurgitated either per period or per day were not related to the fibre content of the diet (P > 0·05).The regurgitated boluses from leaf fractions were chewed less than the stem fractions (43·7 v. 54·7 chews per bolus). The regurgitated boluses of lucerne leaf were chewed at a faster rate (1·13 chews per s; P > 0·05) than regurgitated digesta of the other diets which were chewed at similar rates (0·97 chews per s; P > 0·05). The total number of rumination chews made each day by animals given lucerne leaf (12 300) was much lower (P< 0·001) than that by animals given the other fractions (25 300). The number of chews made on each bolus was related to fibre levels in the diets (NDF, r = 0·78, P< 0·05; ADF, r = 0·91, P< 0·01).It is concluded that the voluntary intake of high-fibre diets is not always restricted by rumen fill or rumination. The ease with which forage is eaten should be investigated as a factor influencing intake of fibrous forages.
G. D. Hutson
Animal Production, Volume 48, pp 561-569;

Operant methods were used to measure the responsiveness to earth of five groups of seven weaner piglets held in a flat-deck cage. Lifts on a lever produced access to an earth trough, an empty trough, or had no effect. Group lever lifting performance was unaffected by earth in the trough, but at least one individual, the ‘worker piglet’, operated the lever more than the others to gain access to earth. Once the lid of the trough was opened other piglets were attracted to the earth and spent more time using the earth trough than the empty trough. Previous experience of earth appeared to modify lever lifting behaviour. In one group, a worker piglet did not emerge, and in another the worker operated the lever for earth at a reduced rate. The number of piglets using the earth trough and the amount of time spent utilizing it was reduced by prior exposure to earth. It is concluded that earth is a mild reinforcer to weaner piglets, that it will sustain a low rate of responding on an operant schedule, and that a component of its reinforcement value is its novelty.
A. Brosh, Z. Holzer, D. Levy
Animal Production, Volume 48, pp 513-518;

The use of cottonseed (CS) as an energy and protein supplement to high wheat-straw diets was studied in a digestion and nitrogen balance trial, and as a component in fattening diets in a feeding trial. The proportions of CS studied were 0, 60, 120, 180 and 240 g/kg diet dry matter (DM). DM intake per kg M0·75 was 33, 31, 40, 31 and 29 g, respectively. The digestibility coefficient of organic matter was 415, 463, 417, 441, 350 g/kg DM and of neutral-detergent fibre was 350, 436, 411, 309, 334 g/kg DM. Nitrogen balance was –2·52, 1·1, 5·38, 5·63, 7·60 g/day respectively, for the same order of treatments. The effect of high proportions of CS in the diet in restricting DM intake and reducing its digestibility was evident. The results of the feeding trial were in agreement with those of the digestion trial and indicate the proportion of 120 g CS per kg DM as optimal and maximal.
S. G. Revell, C. E. Glossop
Animal Production, Volume 48, pp 579-584;

Semen was collected from boars of proven fertility and diluted with Zorpva base using the antibiotic treatments: benzylpenicillin and streptomycin; polymixin B; tylosin; neomycin; gentamycin; kanamycin or lincomycin and spectinomycin. The last combination provided an economical treatment with enhanced quality and preservation of motility. The addition of trehalose (1 g/1) and potassium chloride (0·25 g/1) improved the preservation of acrosomes. The resulting ‘Reading’ variant was compared with Zorpva at days 4 to 6 of storage in a split ejaculate trial using 40 sows slaughtered 9/10 weeks after insemination. Conception rates were significantly higher using Reading (16/20) compared with Zorpva (8/20; P< 0·05) and the effect was particularly marked at days 5 and 6. The mean number of embryos per pregnant sow was 11·6 (Reading) v. 9·4 (Zorpva), representing 51% and 42%, respectively, of ova shed, as measured by counting corpora lutea.
R Geers, B. Dellaert, V. Goedseels, A. Hoogerbrugge, E. Vranken, F. Maes, D. Berckmans
Animal Production, Volume 48, pp 571-578;

Air temperatures were measured every 2 h in 12 growing-finishing pig houses. All houses were operated on the all-in, all-out, principle. Data were collected for two fattening periods in each house. Stocking density, feeding system, pig type, and the farmer's skill were standardized. Every 2 weeks, the houses were visited and live weight, mortality rate, the incidence of coughing and tail biting, and the extent of dirty lying areas were recorded. Air temperature limits could be isolated from the complex of factors affecting behavioural and health problems of pigs observed within these experiments. Sensitive periods within the growth period of the pigs seem to exist. At the onset of the fattening period (20 to 30 kg), pigs which have been transported from other farms need special care. During summer, mortality rate was lowered when the periodicity of the temperature cycles was lowered for 40- to 50-kg pigs, whereas for heavier pigs the mean maximal air temperature was important also. With respect to coughing, a statistically significant negative relation with the air temperature in the pig house was found for all weight classes, with interactions from the number of different temperature cycles within a 24-h period. In order to avoid dirty lying areas for 20- to 40-kg animals, air temperatures should be between 20 to 24°C, whereas for diarrhoea, animals of 40 to 50 kg were especially sensitive to the occurrence of low air temperatures. For minimizing tail biting, an optimal air temperature range of 20 to 22°C is suggested.
A. J. Kempster
Animal Production, Volume 48, pp 483-496;

The relationship between carcass and meat quality research and industry requirements is examined with reference to changes in consumer demand. It is argued that much applied research has not focused sharply enough on commercial requirements and that technology transfer has been slow. But there are signs that the pace of future development will be faster, associated with a reorientation of research objectives. The three key factors stimulating change are as follows. (1) Increasing demand by retailers for a consistent product (a demand enforced by the buying power of the major multiple grocers). (2) The reappraisal by breeders of selection objectives. (3) Recent developments in sensor technology and the exploitation of information technology at the producer-processor interface. The implications of each of these are discussed. Driven by these factors research will be targeted increasingly on integrated systems from production to consumption, aimed at specific markets setting different balances between production costs and quality. These will be blueprints for best operating practices and the ‘state of the art’ against which new research developments will be evaluated. Throughout the review, emphasis is placed on the importance of good communication between research workers and industry to confront change and realize the opportunities created.
K. Nath, D. K. Agrawal, Q. Z. Hasan, S. J. Daniel, V. R. B. Sastry
Animal Production, Volume 48, pp 497-502;

A full lactation (300 days) experiment on 32 crossbred milch cows, separated into two groups was carried out. Group 1 (control) was given a concentrate mixture consisting of 400 g groundnut cake, 300 g crushed maize, 270 g wheat bran, 20 g mineral mixture and 10 g common salt per kg; while in group 2 (experimental) the groundnut cake was replaced by water-washed neem seed kernel cake (WWNSKC). Roughage was common in both the groups. Digestion and balance study on nine cows in group 1 and eight in group 2 was carried out after 3 months experimental feeding. Milk yield was recorded twice daily and butter fat, protein and total solids were determined every month in the milk of each animal. The results showed that there was no significant difference (P > 0·05) in the milk yield, butter fat content, organoleptic evaluation of milk, dry-matter intake, digestibility of nutrients, haemoglobin, SGOT, SGPT, acid phosphatase and alkaline phosphatase in blood and reproductive ability of the cows in the two groups. The nitrogen balance was higher in the WWNSKC group (P< 0·05) due mainly to less excretion of urinary nitrogen and a concomitent decrease in blood urea nitrogen. It is concluded that water washing of neem seed kernel cake, whose potential availability in India alone is about 0·9 Mt annually, can convert this cake, hitherto going waste, into an excellent high protein animal food and can be used for feeding milch animals without any adverse effect. It is recommended that this technology be adopted by all neem seed-cake producing countries, specially those developing countries having chronic shortage of foods and fodders for animal feeding.
C. T. Whittemore, H. Yang
Animal Production, Volume 48, pp 203-212;

The physical and chemical composition of sows was determined at first mating (no. = 6), weaning the first litter (12) and 14 days after weaning the fourth litter (24). The sows were from 108 Large White/Landrace Fl hybrid gilts allocated in a factorial arrangement according to two levels of subcutaneous fatness at parturition (12 v. 22 mm P2), two levels of lactation feeding (3 v. 7 kg) and two sizes of sucking litter (six v. 10). Treatments significantly influenced the composition of dissected carcass fat and chemical lipid, but not composition of dissected lean and chemical protein. The final body protein mass of well fed sows at the termination of parity 4 was 41 kg, and the total content of gross energy (GE) in excess of 3000 MJ, with an average of 12·4 MJ GE per kg live weight; equivalent values for the less well fed sows were 33 kg and 9·4 MJ GE per kg live weight respectively. The weights of chemical lipid and protein could be predicted from the equations: lipid (kg) = -20·4 (s.e. 4·5) + 0·21 (s.e. 0·02) live weight + 1·5 (s.e. 0·2) P2; protein (kg) = -2·3 (s.e. 1·6) + 0·19 (s.e. 0·01) live weight - 0·22 (s.e. 0·07) P2. On average, sows lost 9 kg lipid and 3 kg protein in the course of the 28-day lactation; these being proportionately about 0·16 and 0·37 of the live-weight losses respectively. Maternal energy requirement for maintenance was estimated as 0·50 MJ digestible energy (DE) per kg M0·75, while the efficiency of use of DE for energy retention was 0·28.
R. H. King
Animal Production, Volume 48, pp 241-244;

Seventy-eight gilts in replicates of three litter-mates were allocated at 135 days of age and 65·4 kg live weight among three treatments. Between allocation and mating gilts were given either 1·78 kg/day (LL) or 2·72 kg/day (LH) diet containing 12·3 MJ digestible energy (DE) per kg and 5·3 g lysine per kg or 2·57 kg/day (HH) diet containing 12·6 MJ DE per kg and 8·1 g lysine per kg. More gilts in the LH and HH groups attained puberty within 200 days of age than LL gilts (41/52 v. 72/26, X2 = 8·9, P< 0·01). Live weight at conception was 93·8, 105·3 and 108·9 kg for LL, LH and HH gilts respectively at a mean age of 203 days. Subsequent reproductive efficiency and sow body weight and backfat changes were not significantly affected by treatments imposed during the early stages of reproductive life.
G. J. T. Swanson, H. Joanne Bellamy
Animal Production, Volume 48, pp 37-41;

Two pedigree indexes were calculated for 754 Friesian/Holstein bulls born between 1974 and 1980 and tested by the Milk Marketing Board. Correlations between the indexes and the average progeny performance were used to compare the indexes calculated using information from different ancestors. The first index, or estimated predicted difference (EPD) was calculated as one-half the sire progeny test, known as an Improved Contemporary Comparison (ICC), plus one-quarter the maternal grandsire ICC. The second index or estimated ICC (EICC) was calculated from one-half the sire ICC plus one-half the dam cow genetic index (CGI). The correlations between the deregressed bull evaluations (DICC) and EPD, calculated from 310 bulls, were 0·40 for milk yield, 0·40 for fat yield and 0·39 for protein yield. The corresponding correlations between the DICC and EICC, calculated from 314 bulls, were 0·43, 0·40 and 0·41. The regression coefficients for predicting average progeny performance from the EPD index were 1·00 (s.e. 0·13), 0·97 (s.e. 0·12), 0·96 (s.e. 0·13), 1·09 (s.e. 0·12) and 1·08 (s.e. 0·10) for milk, fat and protein yield, fat and protein percentage respectively. Those for predicting progeny performance from the EICC index were 0·95 (s.e. 0·11), 0·81 (s.e. 0·10) and 0·84 (s.e. 0·10) for milk, fat and protein yield respectively. Although the correlations were lower than the expected values of 0·50 (EPD) and 0·55 (EICC) the regressions were near the expected value of 1. The results indicate that the indexes are useful as a preliminary means of selecting bulls prior to progeny testing.
, T. T. Treacher
Animal Production, Volume 48, pp 109-120;

In two experiments, six silages were offered either alone or with constant daily levels of a barley-based concentrate (450 or 900 g fresh weight per ewe) to Finn Dorset ewes carrying between one and four foetuses in the last 6 weeks of pregnancy. The silages (SI to S3, experiment 1 and S4 to S6, experiment 2) had dry matter (DM) concentrations of 256, 190, 278 and 294, 216, 201 g/kg fresh weight and crude protein (CP) concentrations of 106, 164, 212 and 119, 148, 194 g/kg DM. Mean metabolizable energy (ME) concentrations of the silages (digestible energy × 0·81), in weeks 16 and 20, were 9·2, 10·3, 12·0 and 8·8, 10·9, 11·0 MJ/kg DM. Total ME intakes were 12·6, 13·5, 18·6 and 14·5, 15·1, 16·8 MJ/day in week 16 of gestation and were 11·6, 11·2, 17·2 and 12·2, 11·8, 13·3 MJ/day in week 20. Total ME intakes were increased by offering higher levels of concentrates and for levels of 0, 450 or 900 g/day these were 12·3, 14·8, 17·9 MJ/day in week 16 and 9·6, 12·8, 15·5 MJ/day in week 20. Intakes were similar for ewes carrying twins or multiples in experiment 1, but in experiment 2, intakes by ewes with twins or multiples were proportionately 0·97 and 0·85 of those for ewes with singles. Replacement rates of forage by concentrates were —0·09, —0·08, —0·60 and —0·06, —0·25, —0·38 g silage organic matter (OM) per g concentrates OM for silages SI to S3 and S4 to S6. Only on silage S6 did the replacement rate differ significantly from zero.
M. R. Anous
Animal Production, Volume 48, pp 121-129;

A total of 52 ram lambs of different morphological types slaughtered at a comparable stage of body development (carcass weights = 19·5 (s.d. 3·10) kg) were used to study the variation in the relationship between muscle and bone development in the hind limb using multivariate techniques. Development of individual muscles was expressed relative to the weight of the major bone to which they are closest, considered here as their carrier bone.Variability of muscle: bone ratios of individual muscles varied considerably from one muscle to another. The coefficient of variation (CV) ranging from 0·111 to 0·462 (average CV = 0·199). Relative to the same bone, the variability of muscle: bone ratios for each of the three anatomical regions of the hind limb was still important. This suggests that variability may be due to other factors besides muscle weight, such as bone shape.The correlation between the various muscle: bone ratios was low in some cases. However, a significant association existed between muscle: bone ratios of individual muscles and the total muscle: bone ratio in the hind limb which indicated that some muscle: bone ratios can be used as indicators of muscling in the selection of meat animals such as m. semimembranosus/femm, m. gluteobiceps/femur, m. adductores/'femur and m. semitendinosus/femur.The most discriminant variables of the population in multivariate analysis were m. soleus/tibia, m. extensor digitorium lateralis/tibia, m. quadmtus femoris/coxal, m. gemelli/coxal and m. vastus medialis/femur. It was also possible to distinguish the different morphological types of the different breeds by the values of the ratios between these variables.
, A. J. F. Russel, E. A. Hunter
Animal Production, Volume 48, pp 43-50;

Fifty-four Charolais-cross weaned suckled calves were used in an experiment to investigate the effects of feeding level during the post-weaning winter on their subsequent performance, when grazing different vegetation types in summer. During winter they were given grass silage and barley at one of three levels (low, medium and high). The winter live-weight gains were 0·50, 0·75 and 0·96 (s.e. 0·019) kg/day (P< 0·001) for the low, medium and high treatments respectively. During summer they grazed either a sown ryegrass pasture (S), a hill reseed (R) or part of an unimproved hill (H).Live-weight gain during summer was inversely related to winter feeding level on all grazing treatments, the mean live-weight gains being 1·01, 0·79 and 0·65 (s.e. 0·027) kg/day (P< 0·001) for the low, medium and high winter feeding levels respectively. Summer treatment significantly affected performance, the live-weight gains being 0·88, 0·94 and 0·61 (s.e. 0·027) kg/day for the S, R and H treatments respectively. There was no interaction between winter and summer feeding treatment on live-weight gain. The organic matter intake was highest on the H treatment but the digestibility of herbage consumed was the lowest, resulting in the lowest digestible organic matter intake.Similar and high levels of performance were obtained on sown ryegrass pastures and reseeded hill land, while unimproved hill vegetation supported only moderate levels of live-weight gain. Compensatory growth occurred when a wide range of vegetation types were grazed in summer.
J. E. Vipond, Margaret E. King, E. R. Ørskov, G. Z. Wetherill
Animal Production, Volume 48, pp 131-138;

The effect of undegradable protein supply was studied in overfat lambs given low-energy diets to reduce carcass fatness. Two trials involving sequential batches of 48 overfat Suffolk × lambs investigated the effects of supplementing an ad libitum straw diet with either 0 or 100 g fish-meal pellets daily for 14-, 28- and 42-day periods. Lambs supplemented with fish meal in trials 1 and 2 lost significantly less weight. Weight losses (g/day) were - 2 v. -129 (s.e.d. 26) and -5 8 v. -188 (s.e.d. 29) respectively. There were highly significant and favourable effects of fish-meal supplementation on carcass weight and composition (recorded in the second trial only). Carcass weight (kg) after 14, 28 and 42 days was 21·8, 20·4 and 18·3 for unsupplemented lambs and 22·4, 21·9 and 21·6 for supplemented lambs; saleable lean (kg) as determined by a commercial boning-out process was 12·1, 11·3 and 10·0 v. 12·7, 12·6 and 12·3 respectively. There were corresponding changes in conformation but fat trimmed off the carcass was not significantly reduced by the dietary treatments. There was, however, a reduction by one-fifth in excess carcass fat (about 0·5 kg) over the period 14 to 42 days on trial, and over the trial as a whole, fat trim fell from an estimated proportion of carcass weight of 0·17 to 012, equivalent to a fall in Meat and Livestock Commission fatness score from 4H to 3L. Results indicated very favourable financial rewards for supplementing diets of overfat lambs with fish meal.
A. G. de Vries
Animal Production, Volume 48, pp 221-227;

The value of the improvement of a trait for a breeding organization is determined by its impact on the saleability of its breeding stock. This impact is influenced by the competitive position of the breeding organization, i.e. by the performance of its breeding stock relative to other breeding organizations. A method was developed to take effects of competitive position on the breeding goal into account in designing selection indexes. The main conclusions were as follows. (1) When the performance level of a trait is equal to the average performance level of other breeding organizations, its economic weight (i.e. its weighing factor in the breeding goal) is equal to its importance on a commercial level. With lower performance, the economic weight increases. With higher performance, it decreases. (2) The effect of competitive position on the economic weight of a trait depends on the degree of compensation between traits. When a weakness (negative monetary deviation compared with competitors) n i one trait can be totally compensated by the strength (positive monetary deviation of the same order) i n another trait, then competitive position has no influence on the economic weight.
J. A. Woolliams
Animal Production, Volume 48, pp 31-35;

The value of cloning in MOET nucleus breeding schemes has to be considered within the constraint of fixed resources. Under this constraint cloning was found to add to genetic progress only when (i) the heritability is low and (ii) it is used at the expense of a reduction in the number of bull families. This course would exacerbate inbreeding and other potential problems with MOET. All other options for using clones lead to a reduction in genetic progress due to a loss of selection intensity that is not made up for by gains in selection accuracy.
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