Journal of Applied Animal Nutrition
EISSN : 2049-257X
Published by: Wageningen Academic Publishers (10.3920)
Total articles ≅ 104
Latest articles in this journal
Journal of Applied Animal Nutrition pp 1-12; https://doi.org/10.3920/jaan2021.0010
A study was conducted to evaluate the effects of supplemental protease and cereal grain type on nutrient digestibility (jejunum and ileum) and performance of broilers offered diets with reduced amino acid concentrations and supplemental xylanase and phytase. A total of 624 male broiler chicks (Ross 308) were randomly distributed into 48 floor pens (13 chicks/pen; 0.07 m2/bird) and offered one of six dietary treatments with eight replicates per treatment. Dietary treatments were either maize- or wheat-based with a positive control (PC) reference diet, a negative control diet without protease (NC; 60 g/kg lower amino acid density than PC), and an NC diet with protease. The reduction in amino acid density affected (P<0.05) nutrient digestibility by varying degrees depending on cereal grain source. At 14 d of age, cereal grain and protease showed a significant interaction (P<0.05) which affected jejunal and ileal starch digestibility, whereby protease increased digestibility in birds fed wheat-based diets but not in those fed maize-based diets. Cereal grain source affected (P<0.05) nitrogen (jejunum and ileum) and digestible energy (DE; ileum), where birds fed wheat-based diets had higher digestibility than those fed maize-based diets. At 28 d of age, birds fed wheat-based diets had a higher (P<0.01) jejunal and ileal nitrogen digestibility, whereas protease reduced ileal nitrogen digestion. Protease affected ileal starch digestion in birds fed wheat, but not maize-based diets, resulting in a significant cereal grain × protease interaction (P<0.05). Wheat-based diets had a higher DE than maize-based diets in both the jejunum and ileum. From 15 to 35 d of age, cereal grain source (P<0.05) affected performance, whereby broilers offered maize-based diets had better performance than those fed wheat-based diets.
Published: 30 September 2021
Journal of Applied Animal Nutrition pp 1-6; https://doi.org/10.3920/jaan2021.0009
A volatile herbal extract (VHE), consisting of 150 g/kg anethole, 15 g/kg bebaudioside A, 2.1 g/kg thymol, 2.0 g/kg eugenol and 2.3 g/kg cinnamic aldehyde, was fed to sows and their weaned offspring to evaluate its effect on the reproductive performance of sows and the growth performance of weaned piglets. A total of 18 sows (Landrace × Yorkshire) were randomly assigned to dietary treatments based on average parity (1.78) with nine replicates per treatment. The feeding period was 35 days, from d 7 before farrowing to d 7 after weaning. The lactation period was 21 d. A total of 96 piglets were randomly selected from each sow treatment group and allocated to 24 replicate pens with four pigs (mixed sex) per pen. The feeding period of weaned piglets was 35 days (phase 1, days 1-7; phase 2, days 8-21; phase 3, days 22-35). Dietary treatments in sows and weaned piglets consisted of a basal control diet with or without 500 mg/kg VHE. The data showed that VHE supplementation had no effect on the reproductive performance of sows, but improved the growth performance of weaned piglets, in which the increase of average daily gain during days 1-7 (P=0.006) and 1-35 (P=0.032) and feed efficiency during days 22-35 (P=0.026) and 1-35 (P=0.020) in weaned piglets were observed. Therefore, supplementing VHE to the diet of sows and their weaned offspring was beneficial to the growth performance of weaned piglets.
Journal of Applied Animal Nutrition, Volume 9, pp 99-103; https://doi.org/10.3920/jaan2021.0006
Greenhouse gas (GHG) emissions from livestock are an important consideration in environmental science. Estimating GHG production can be problematic at a farm or animal level, and requires controlled conditions to produce real data. An in vitro gas production technique (IVGPT) was developed to evaluate forage-based total mixed rations in digestion kinetics and GHG production. Two hundred and sixty samples of complete mixed rations (MR), which included a pasture component used in commercial lactating dairy herds, were collected around NZ across three calendar years, 2017-2019. Twenty of the 260 samples were 100% total mixed rations (TMR) with no pasture content. The samples were submitted for proximate analysis as well as IVGPT to generate GHG production figures. The results showed an average total gas production (TGP) of 129.82 ml/g dry matter (DM), 78.6% true digestibility (TDMD), 125.06 mg/g DM microbial biomass (MB), 20.16 g CH4/kg DM, and 12.8 MJME/kg DM. The average nutrient composition was dry matter (DM) 31.55%, crude protein (CP) 21.85%, neutral detergent fibre (NDF) 44.35%, and starch 7.03%. The IVGPT CH4 production was negatively correlated to NDF (r=-0.312), ADF (r=-0.193), TGP (r=-0.216), and was positively correlated with TDMD (r=0.250), apparent digestibility (ADMD) (r=0.614), starch (r=0.117) and volatile fatty acids (r=0.538). The MR diet showed a strong positive relationship with ADMD digestibility (P=0.01) and a negative relationship with fibre content (NDF, P=0.01 and ADF, P=0.01). However, CH4 production reduced linearly with increasing TGP (P=0.01). The results indicated that a greater CH4 production may be related to higher digestibility of mixed ration.
Journal of Applied Animal Nutrition, Volume 9, pp 85-91; https://doi.org/10.3920/jaan2021.0007
This experiment evaluated the effects of supplemental protease in maize-based diets formulated with reduced density of digestible amino acids (dAA) on net energy (NE) utilisation and nutrient digestibility in broilers. A total of 312, one-day-old, male broilers (Ross 308) were randomly distributed into 24 floor pens and fed one of three treatments, with eight pen replicates per treatment throughout the starter (1 to 14 d of age) and grower (15 to 28 d of age) phases. Dietary treatments consisted of a positive control (PC) reference diet, a negative control diet (NC; dAA density 60 g/kg less than PC diet), and a NC diet with supplemental protease (200 mg/kg). All diets contained supplemental phytase (200 mg/kg) and xylanase (200 mg/kg). The reduction in dAA density between the PC and NC did not affect (P>0.05) NE, but protease supplementation in the NC diet increased (P0.05) affect nitrogen, starch, or DE in the jejunum or ileum. Likewise, no differences (P>0.05) in jejunal (nitrogen, starch, and DE) and ileal (starch and DE) digestibility values were observed between those offered the NC diets without or with protease, but a small difference (P<0.05) in ileal nitrogen digestibility was observed.
Journal of Applied Animal Nutrition, Volume 9, pp 93-98; https://doi.org/10.3920/jaan2021.0005
The influence of method (direct vs difference method) used to determine the apparent ileal digestibility coefficient (AIDC) of amino acids in two cereals (maize and wheat) and two grain legumes (Australian sweet lupins and peas) was investigated. For the direct method, the test ingredients were incorporated as the sole source of protein in assay diets. The assay diets used in the difference method were formulated by substituting the cereals and legumes for 50 and 25% (w/w), respectively, of a maize-soy basal diet. Each diet contained 3 g/kg titanium dioxide as an indigestible marker and were offered ad libitum to four replicate cages of broilers (four birds/cage) from d 28 to d 35 post-hatching. On d 35, digesta were collected from the terminal ileum and the AIDC of amino acids were calculated using marker ratios in the diet and digesta. Except for histidine, methionine, cysteine and tyrosine, the main effect of methods was found to be significant (P<0.05 to 0.001) for the AIDC of all amino acids. The main effect of the ingredients was significant (P<0.05 to 0.001) for all amino acids, except for histidine, aspartic acid and serine. Interactions (P<0.05) between ingredients and method were observed only for leucine, lysine, proline and serine. The AIDC of amino acids, determined by the difference method, was found to be distinctly higher than those determined by the direct method. This suggested that the direct method underestimated amino acid digestibility in low and medium protein ingredients.
Journal of Applied Animal Nutrition, Volume 9, pp 65-75; https://doi.org/10.3920/jaan2021.0003
Recent research has questioned the notion that Campylobacter jejuni is a harmless resident of the avian gastrointestinal tract (GIT). The following trial examined the effect of dietary supplementation with a mixture of enzymes and Bacillus-based probiotics on growth performance, C. jejuni colonisation, GIT immune responses, faecal shedding and extra-intestinal spread in broilers. Fifty-eight, Ross 308 d-old broilers were randomly assigned to one of four treatments, giving 14 or 15 birds/pen. Birds were given nutritionally complete, complex, phased diets unsupplemented (two treatments) or supplemented (two treatments) with a multi-enzyme containing 2,000 U/kg xylanase, 200 U/kg amylase and 4,000 U/kg protease, and 75,000 cfu/g of a combination of three strains of Bacillus amyloliquefaciens. One control and one supplemented diet group contained birds orally challenged with 105 cfu C. jejuni strain M1 on d 21 of age. Among challenged birds, the mixed-enzymes and probiotic combination numerically reduced faecal C. jejuni shedding (-98% vs challenged control) three days-post-infection (d.p.i.), and at 7 d.p.i. numerically reduced C. jejuni colonisation of the ileal mucosa (-1000-fold vs control) and totally inhibited systemic spread of C. jejuni to the liver, compared to the control (P<0.05). It suppressed early pro-inflammatory chemokine response seen in the ileum, caecum and caecal tonsil tissues (at 3 d.p.i.) in challenged control birds (-18 to -46-fold; P<0.05) and altered expression of pro-inflammatory (IL-1β, IL-6, IL-17A and IL-17F) and regulatory (IL-10 and TGF-β) cytokines. The data demonstrated inhibition of a sustained pro-inflammatory response to C. jejuni infection and improved intestinal barrier integrity in supplemented birds. This highlighted the importance of looking beyond simple measurements of feed conversion and body weight gain when seeking to understand the effects and mode of action of poultry dietary interventions. Achieving a favourable balance between the gut, immune function, microbiome and nutrition should be the goal for achieving good gastrointestinal health and optimal performance.
Journal of Applied Animal Nutrition, Volume 9, pp 77-83; https://doi.org/10.3920/jaan2021.0004
The following study evaluated effects of a xylanase and beta-glucanase combination on growth performance of broilers fed energy reduced versus nutritionally adequate maize-soybean meal-based diets. A total of 648, one-day-old male broilers (Ross 308) were assigned to floor-pens (24 birds/pen, nine pens/treatment, three treatments) in a randomised block design. Treatments included: (1) a nutritionally adequate positive control diet (PC); (2) a negative control (NC) diet in which energy, crude protein and digestible amino acids were reduced by 3.4% (-105 kcal apparent metabolisable energy), 2.3% and 1.2 to 3.0% vs PC, respectively; and (3) NC plus a xylanase and beta-glucanase combination that supplied 1,220 U xylanase and 152 U beta-glucanase per kilogram of final feed. All diets contained a background of 500 FTU/kg phytase and were offered to birds ad libitum. Birds fed NC showed reduced average daily gain (ADG) by -6.1% (P<0.05); increased feed conversion ratio (FCR) by 9.2 points (P<0.05), and overall (d 1-35) body weight corrected FCR which was increased by 9.4 points (P<0.05) vs the PC group. Enzyme supplementation increased final BW (+4.2%, P<0.05), ADG (+5.4%, P<0.05) and tended to reduce FCR (+7.5 points, P=0.054) from d 22-35 vs NC, without affecting average daily feed intake. Improvements in performance due to the enzyme combination were equivalent to performance on the PC diet in all cases. The results suggested that significant improvements in growth performance of broilers fed maize-soybean meal-based diets which had been reduced in energy and nutrients can be realised by supplementation with xylanase in combination with beta-glucanase.
Journal of Applied Animal Nutrition, Volume 9, pp 1-7; https://doi.org/10.3920/jaan2020.0013
The aim of this study was to evaluate the impact of a probiotic Bacillus licheniformis strain (DSM 28710; B-Act®) on growth performance and its capacity to mitigate necrotic enteritis (NE; induced via a Clostridium perfringens challenge) in poultry. A broiler trial was conducted, examining three treatments for 42 days under an induced NE challenge; a negative control (basal diet only); an antibiotic treated group (oxytetracycline hydrochloride (OXT), therapeutic dose of 105 mg OXT/litre in drinking water, for three days after C. perfringens challenge); and a B-Act group (500 g B-Act/tonne of feed, equalling 1.6×1012 colony forming units B. licheniformis DSM 28710/tonne of feed, supplemented from start until finish). Despite the induced NE challenge, weight gains of the B-Act and OXT groups were similar to each other but significantly higher compared to the control at the end of the study (P<0.05). Weight gain of the B-Act group was already significantly higher compared to the control on day 21 (P<0.05), indicating a potential benefit of the probiotic even before clinical establishment of NE. Feed conversion ratio (FCR) values followed a similar pattern throughout the study, with a significantly lower overall FCR for the B-Act and OXT groups compared to the control (P<0.05; d0-42). Birds fed B-Act had significantly (P<0.05) lower NE lesions compared to the control and OXT group on day 21, although OXT was not supplemented to the animals at this stage yet. Both B-Act and OXT groups had significantly (P<0.05) lower NE scores than the control on day 28, demonstrating the effectiveness of the antibiotic treatment and the mitigating effect of B-Act on the effects of a Clostridium perfringens induced NE challenge.
Journal of Applied Animal Nutrition, Volume 9, pp 23-30; https://doi.org/10.3920/jaan2020.0018
The aim of this trial was to compare the effect of complete replacement of certain inorganic trace minerals with organic, chelated minerals (Bioplex®, Selplex®; Alltech Inc, USA) against standard and reduced inorganic mineral levels in feed on the performance and health of dairy cows during a 10-week trial (W0-W10) period. Three treatment groups, each containing 36 dairy cows, were assigned to one of three diets that varied only in mineral feed composition: (1) Inorganic (CON) Cu (1,042 mg/kg), Se (26 mg/kg) and Zn (4,200 mg/kg) as per normal industry inclusion levels; (2) Inorganic (INORG) Cu (-35%: 680 mg/kg), Se (-60%; 10 mg/kg) and Zn (-66%; 1,360 mg/kg) (based on the lower organic levels in diet 3); and (3) Organic (proteinates and selenium-enriched yeast) minerals (ORG) Cu, Se and Zn as per INORG levels. The cows in the ORG group had the highest milk yield (32.6 kg; P=0.0165) with the INORG group the least (31.3 kg), production (energy corrected milk 31.5 kg (P=0.008) vs CON 31.0 kg and INORG 30.7 kg), protein synthesis (ORG 1,024 g/d (P<0.0001) vs CON 1,013 g/d and INORG 982 g/d) and ORG had the highest (P<0.01) milk lactose content. There were no differences between treatments in plasma Zn, Cu and GSH-PXE levels. Pregnancy rate and number of artificial insemination services appeared improved. Mastitis rates were lowest for the ORG group (two cows affected), vs four cows for the INORG group and six cows for the CON group. Somatic cell counts were consistently lower in the ORG cows (P<0.05), being less than 300,000 cell counts, compared to peaks of 380,000 counts in the INORG and 550,000 counts in the CON groups. Five cows were affected by lameness in the INORG group, compared to three for the CON and one in the ORG groups.
Journal of Applied Animal Nutrition, Volume 9, pp 31-56; https://doi.org/10.3920/jaan2020.0017
Ruminants have adapted to cope with bulky, fibrous forage diets by accommodating a large, diverse microbial population in the reticulo-rumen. Ruminants are dependent on forages as their main sources of energy and other nutrients. Forages are comprised of a complex matrix of cellulose, hemicellulose, protein, minerals and phenolic compounds (including lignin and tannins) with various linkages; many of which are poorly defined. The composition and characteristics of polysaccharides vary greatly among forages and plant cell walls. Plant cell walls are linked and packed together in tight configurations to resist degradation, and hence their nutritional value to animals varies considerably, depending on composition, structure and degradability. An understanding of the inter-relationship between the chemical composition and the degradation of plant cell walls by rumen microorganisms is of major economic importance to ruminant production. Increasing the efficiency of fibre degradation in the rumen has been the subject of extensive research for many decades. This review summarises current knowledge of forage chemistry in order to develop strategies to increase efficiency of forage utilisation by ruminants.