Revista Brasileira de Zootecnia
EISSN : 1516-3598
Published by: SciELO (10.1590)
Total articles ≅ 4,723
Latest articles in this journal
Revista Brasileira de Zootecnia, Volume 46, pp 731-739; https://doi.org/10.1590/s1806-92902017000900004
Two experiments were conducted to evaluate combinations of different storage periods and temperature of hatching eggs of breeder quails in two stages of the production cycle (24 and 43 weeks) on hatchability, quail neonate quality, and Bursa of Fabricius characteristics. In each experiment, a total of 1.050 Japanese quail eggs were incubated in a randomized block design in a factorial arrangement of 2 × 5 × 2, with two breeder ages (24 and 43 weeks), five storage periods (one, three, six, nine, and twelve days), and two storage temperatures (28 and 14 °C), totaling 20 treatments with 52 eggs each. Quantitative data were subjected to ANOVA and means were compared by Tukey's test. Qualitative data were subjected to Friedman's test. Polynomial regression analysis was performed in relation to the storage period of the eggs. Hatchability of 43-week-old breeders worsened as the storage period increased at 28 °C, while at 14 °C, hatchability was not affected. Yolk-free body weight was influenced only by storage period; therefore, the group stored for 12 days had the lowest yolk-free body weight. Twelve days of storage reduced the absorption of yolk residue and physical quality score and also affected neonate quail immunity. Fertile eggs from Japanese quails that are destined for incubation should be stored at 14 °C to maintain physical and immunological quality of the progeny. Moreover, eggs from older breeders originate lower-quality quails when eggs are not stored in a refrigerated environment.
Revista Brasileira de Zootecnia, Volume 46, pp 705-713; https://doi.org/10.1590/s1806-92902017000900001
This study aimed to assess the final body weight, weekly weight gain, yield, apparent feed efficiency, protein efficiency ratio, and feed intake of the Pacific white shrimp (Litopenaeus vannamei) fed four diets containing different levels of soy protein concentrate (SPC) as a replacement for fishmeal, reared in a super-intensive biofloc system. Diets consisted of replacing 209 g kg-1 fishmeal at 0, 33, 66, and 100% SPC. Shrimp were raised in a biofloc system using twelve experimental units stocked with 250 shrimp m-3 under constant aeration (O2>5mg L-1) and temperature (29±0.5 °C). No significant differences among treatments were observed based on water quality parameters. Shrimp fed diets with 0 and 33% substitution exhibited the highest weekly growth (1.88 and 1.79 g per week) and final weights (15.2 and 14.7 g) compared with shrimp fed the 66 and 100% replacement. A lower feed intake was observed for shrimp fed the 33% SPC diet (3.18 kg per experimental unit) compared with 0% replacement (3.62 kg). Shrimp fed the 33% replacement achieved a similar performance and lower feed intake than animals fed diet without replacement.
Revista Brasileira de Zootecnia, Volume 46, pp 747-754; https://doi.org/10.1590/s1806-92902017000900006
The objective of this study was to evaluate the effect of prebiotic fructooligosaccharide (FOS) supplementation on the development of Mangalarga Marchador suckling foals. Sixteen Mangalarga Marchador foals, from birth to 75 days of age, were evaluated in a completely randomized design, with two treatments (experimental group and control group) with eight repetitions (animals). The foals were evaluated through body weight, morphometric, and circumferential measures. The daily, weekly, and cumulative weight gains were recorded and the morphometric measures were: withers height, croup height, body length, mid-back height, mid-back width, and thorax, shin, knee, and forearm circumferences. The mean body weight was 32.3 and 77.9 kg at birth and 75 days of age, respectively. The mean withers height was 86 and 103.8 cm at birth and 75 days of age, respectively, and the mean body length was 63.9 cm at birth, reaching 89.1 cm at 75 days of age. No significant differences in the FOS supplementation or interaction of age versus supplementation between the experimental and control groups were observed for any of the parameters evaluated. However, there were significant differences between the ages. Supplementation with prebiotic FOS does not affect the development of the Mangalarga Marchador suckling foals from birth to 75 days of age.
Revista Brasileira de Zootecnia, Volume 46, pp 766-772; https://doi.org/10.1590/s1806-92902017000900009
The objective of the study was to evaluate the replacement of Tifton 85 hay (TH) for Tifton 85 silage (TS) in the diets of lactating cows. Five Holstein cows in middle of lactation were allocated in a 5 × 5 Latin square design and each experimental period lasted 18 days (12 days for adaptation and six days for collection). Treatments consisted of replacement of 0, 25, 50, 75, and 100% of TH for TS. The intake and digestion of nutrients, microbial protein synthesis, milk yield and composition, and the economic viability of the diets were evaluated. The intakes of dry matter, organic matter, and ether extract had a positive linear effect and the digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber decreased linearly with increasing participation of TS. Milk production and composition and microbial protein synthesis were not affected. Regarding economic viability, the treatment with 100% hay produced better results, with better gross margin. The Tifton 85 silage can be used as a replacement for Tifton 85 hay up to 100% without changing the milk production and composition of Holstein cows.
Revista Brasileira de Zootecnia, Volume 46, pp 722-730; https://doi.org/10.1590/s1806-92902017000900003
The objective of this study was to determine the effect of Azospirillum brasilense inoculation and different nitrogen (N) rates applied as topdressing on the productivity of a maize crop and the nutritional value of maize silage. Two experiments were conducted in the 2012/2013 and 2013/2014 harvests. Treatments were distributed in a randomized block design in a factorial arrangement, which consisted of two maize hybrids (AS 1572 and Defender) coupled with nitrogen rates (0, 60, 120, 240, and 480 kg ha-1), inoculated or uninoculated with A. brasilense. Inoculated seeds were treated with the A. brasilense strains Ab-V5 and Ab-V6. Inoculation with A. brasilense showed interaction with the hybrids, agricultural years, and nitrogen rates for the maize plant yield. In the 2012/2013 agricultural year, inoculation increased the AS 1572 hybrid silage yield by 6.16% and, in the 2013/2014 harvest, A. brasilense inoculation produced an increase of 16.15% for the Defender hybrid. Nitrogen fertilization applied at 0, 60, and 120 kg ha-1 N benefited the plants inoculated with A. brasilense. The statistical equations revealed that N rates between 0 and 184 kg ha-1 in A. brasilense inoculated plants raised the plant productivity for silage when compared with the control plants. Regarding the nutritional value of the silage, inoculation with A. brasilense increased the ether extract levels and total digestible nutrients and reduced the amount of acid detergent fiber. For all this, positive results with inoculation for silage yield are dependent on nitrogen fertilization rate. Inoculation with A. brasilense can promote changes in the maize silage quality, but with obtained results it is not possible to definitely conclude upon nutritive value of maize silage.
Revista Brasileira de Zootecnia, Volume 46, pp 760-765; https://doi.org/10.1590/s1806-92902017000900008
The objective of this study was to evaluate the effect of chamomile extract on Japanese quail on their performance, animal behavior, tonic immobility, body injuries, and surface temperature. The trial was conducted using 108 quail distributed in a completely randomized experimental design, with three treatments (0, 2.5, and 5.0 g chamomile/kg of feed), six replicates, and six birds per treatment, evaluated in six measures repeated in time (14, 28, 42, 56, 70, and 84 days of trial). The inclusion of chamomile presented a quadratic effect on sitting behavior, estimating the inclusion of 1.8 g chamomile/kg to maximize this behavior. There was a decreasing linear effect for aggressive pecking, that is, the higher the inclusion of chamomile in the diet, the lower the expression of this behavior. The inclusion of 1.8-5.0 g chamomile/kg in a Japanese quail diet reduces the behavior of aggressive pecking, in addition to keeping the birds seated longer. These results are innovative because they show in the literature for the first time that chamomile supplemented in Japanese quail diets has the capacity to modulate the behavior of the quail, leading to an improvement in the welfare of quail raised in cages.
Revista Brasileira de Zootecnia, Volume 46, pp 714-721; https://doi.org/10.1590/s1806-92902017000900002
The objective of this study was to assess the genetic diversity among accessions of Paspalum notatum based on morphological marker traits and identify those morphological traits that contribute most to the variability among accessions. Fifty-three accessions were evaluated for the following traits: length, width, color, and pubescence of sheath; length, width, insertion angle, color of midrib, and pubescence of leaves; number, length, and angle of racemes; length of flowering stems; and plant growth habit (erect or prostrate). Multivariate analysis of the quantitative morphological data based on the Mahalanobis distance and UPGMA method grouped the accessions into 19 heterogeneous clusters. The relative contribution of each trait to cluster formation was obtained using the Singh method. Qualitative morphological traits were used to construct a dendrogram based on Jaccard's similarity, generating 13 clusters. Based on the morphological traits investigated, there is high genetic variation among accessions of P. notatum, demonstrating that these accessions have a good potential for a breeding program. Length of racemes, width of sheath, length of flowering stems, and length of leaves were found to contribute most to the variability among accessions. A number of traits contributed to a lesser degree. The set of characters used are representative of the vast phenotypic plasticity observed in P. notatum, a diversity which is likely to be related to the species apomictic form of reproduction and the origin of the accessions.
Revista Brasileira de Zootecnia, Volume 46, pp 773-782; https://doi.org/10.1590/s1806-92902017000900010
Inbreeding depression, reduction in performance of quantitative traits, including reproduction and survival, caused by inbreeding, is a well-known phenomenon observed in almost all experimental, domesticated, and natural populations. In spite of its importance to the fate of a small population and numerous research performed in the last century, the genetic basis of inbreeding depression is still unclear. Recent fast development of molecular techniques has enabled estimation of a genomic inbreeding coefficient (FROH), which reflects realized autozygosity and can be further partitioned to chromosomes and chromosomal segments. In this review, we first describe classical approach used in the estimation of inbreeding in livestock populations, followed by early concepts of replacing pedigree inbreeding coefficient by individual heterozygosity. Then, we explain runs of homozygosity as key approach in estimating realized autozygosity. Furthermore, we present two different concepts of analysing regions that substantially contribute to the inbreeding depression. Thus, we describe how to identify or map mutations that result in the reduction of performance and, in terms of quantitative genetics, how to analyse the architecture of inbreeding depression. At the end, we discuss future perspectives in eliminating deleterious mutations from livestock populations.
Revista Brasileira de Zootecnia, Volume 46, pp 755-759; https://doi.org/10.1590/s1806-92902017000900007
The objective of this study was to evaluate a growth model applied to adjust nutritional programs for growing and finishing pigs, in a commercial production context. The phase I (calibration) was conducted in a commercial pig production unit. The data were collected from a nutritional program, a feed program, and an animal profile. In experimental phase II, these data were entered in the InraPorc® model for simulations and to propose adjustments to the commercial nutritional program. Afterwards, the conventional nutritional program (CNP) and the adjusted nutritional program (ANP) were compared with InraPorc® simulation. Animal profile was collected by weighing 30% of pigs per stall and monitoring their feed intake in each stage. Four hundred and thirty-two pigs with an average initial body weight of 21.9 kg were used in a completely randomized design. There were no differences between treatments, the pig performance was affected by temperature conditions, and the fat thickness was 8% higher for CNP than ANP. In conclusion, the model has advantages to adjust growing and finishing pig nutrition programs and improve environmental and economic aspects.
Revista Brasileira de Zootecnia, Volume 46, pp 740-746; https://doi.org/10.1590/s1806-92902017000900005
The objective of this study was to determine the digestibility coefficient (DC) of nutrients and the digestible energy (DE), and metabolizable energy (ME) values of distillers dried grains with solubles (DDGS) produced in Brazil by different methods. Eight barrows with 23.3±4.1 kg were housed in metabolic cages in a randomized block design and fed diets containing 0, 200, 400, and 600 g kg–1 of corn DDGS. We determined the digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), mineral matter (MM), neutral detergent fiber (NDF), and gross energy (GE) by the total collection (TC) and chromium oxide marker (Cr) methods. Distillers dried grains with solubles provided the respective DM, OM, CP, EE, MM, NDF, and GE values of 910, 863, 286, 66.9, 46.8, 500 g kg–1, and 4,780 kcal kg–1. The DE and ME values of DDGS were 3,739 and 3,401 kcal kg–1 and 3,691 and 3,213 kcal kg–1 as determined by TC and Cr methods, respectively. The growing inclusion of DDGS did not affect the DE or ME values. The digestibility coefficients of DM, OM, CP, EE, MM, and NDF were 767, 765, 827, 691, 883, and 821 g kg–1, respectively, by the total collection method. The Cr underestimated the values of all variables compared with TC method. Levels up to 600 g kg–1 of the test ingredient do not influence the DE and ME of DDGS, but compromises the digestibility coefficients of DM, OM, and NDF.