The objective of the trial was to determine the impact of corn source and xylanase on broiler performance, digestibility, and volatile fatty acid (VFA) profiles. Six corn samples were obtained from different regions of the US. Twelve treatments were derived using corn source, with each corn diet being fed with or without xylanase. Three dietary phases were used throughout the trial, starter (d 1–18), grower (d 19–31), and finisher (d 32–41). On d 18 and 41, ileal and excreta contents were collected for the determination of ileal digestible energy (IDE), ileal energy and nitrogen digestibility coefficients (IEDC and INDC), apparent metabolisable energy (AME), and caecal VFA profiles. Day 18 body weight (BW) was affected by corn source and varied between 724 and 764g (P = 0.001). For d 31 BW, there was an interaction of corn source with xylanase (P = 0.001), with the effect of xylanase being inconsistent. The effect of xylanase on feed conversion ratio (FCR) during the grower phase depended on corn source (interactive term, P = 0.021). Xylanase reduced (P = 0.026) FCR during the finisher phase (1.943 vs. 1.992). Variation of corn source influenced digestibility on all evaluated parameters. A range of 152 and 213 kcal/kg for IDE was observed on d 18 and 41, respectively (P = 0.005 and 0.001). The range of AME was 176 kcal/kg on d 18 of age which increased to 194 kcal/kg on d 41. Nitrogen digestibility was influenced by corn source, with an observed range of 4.4 and 6.1% for d 18 and 41, respectively, amongst all corn sources (P = 0.001). Xylanase increased (P = 0.031) the concentration of butyrate in the caecum on d 18. On d 41, an interaction between corn source and xylanase was observed with isovalerate in the caecal contents (P = 0.038). These data demonstrate the impact of varying corn nutrient profiles on nutrient utilisation and growth performance.

The following experiment evaluated the inhibitory activity of a resin acids-based product (RAP) to bacterial pathogens. Clostridium perfringens isolated from chickens, turkeys and pigs, Staphylococcus aureus from chickens, pigs and cattle, and Escherichia coli O149 isolated from pigs were tested. Two different methods were used, a broth dilution method (BDM) using 0.01%, 0.1% and 0.5% resin acid, and an agar diffusion method (ADM) using 0.01%, 0.1%, 0.5%, 1% and 5% resin acid. For the BDM, C. perfringens was inhibited completely at all concentrations. S. aureus was inhibited completely at 0.5%, but only slightly at 0.1% and not at all at 0.01%. The E. coli strains showed no or little inhibition at 0.5%. For the ADM, narrow inhibition zones evolved around the concentration of 0.5% (8–10 mm), 1% (8.0–12.0 mm), and 5% (9.0–19.5 mm) on the C. perfringens strains, while the inhibition zones for S. aureus were smaller and E. coli developed no inhibition zones. Overall, the RAP inhibited C. perfringens at all concentrations of the product, S. aureus at 0.1%, 0.5%, 1% and 5% concentrations, and E. coli O149 only at 0.5% concentrations, although some strain variation was recorded.

The influence of different inclusion levels of a biologically active peptide derived from soybeans by enzymatic hydrolysis, on growth performance, foot pad lesions and carcass characteristics in broilers were examined in this study. Starter (1 to 21 d) and finisher (22 to 42 d) diets, based on maize and soybean meal, were subjected to seven inclusion levels of a commercial soybean bioactive peptide (SBP) product (Fortide, Chengdu Mytech Biotech Co. Ltd., Chengdu, Sichuan, China) at 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 g/kg of diet. All diets were equivalent in respect of energy density, digestible amino acids and other nutrients. A total of 840, one-day-old male broilers (Ross 308) were allocated to 42 pens (20 birds/pen), which were randomly assigned to seven dietary treatments. During the starter period, there was no significant effect of SBP on weight gain and feed intake of the birds. However, a significant (P < 0.05) effect of SBP was observed for the feed conversion ratio (FCR), with SBP inclusion at 3.0 g/kg and above showing lower (P < 0.05) FCR values compared to the diet with no SBP. No effect of SBP was observed for weight gain and feed intake over the whole trial period. However, SBP inclusion tended (P = 0.06) to influence the FCR of birds. Increasing SBP inclusion level resulted in gradual decrease in FCR values, with SBP inclusion at 5.0 and 6.0 g/kg showing lower FCR values compared to the diet with no SBP. Overall, the present study suggests that dietary supplementation of SBP in broiler diets has the potential to improve FCR and to be used as a novel functional protein in poultry diets.

A study was conducted to evaluate productive performance in laying hens fed diets with reduced nutrient density based on the nutritional contribution of a Buttiauxella phytase in laying-hen diets from 21-57 weeks of age. A commercial laying hen diet was offered ad libitum to the 480 ISA Brown laying hens from 18-21 weeks of age. From 21 weeks onwards, the hens received one of four dietary treatments: a positive control (PC) diet, a down specified diet (DS1) + phytase at 300 FTU/kg, a second down-specified diet (DS2) + phytase at 600 FTU/kg and a third test diet formulated as per DS1 + phytase at 1,200 FTU/kg feed. The PC was formulated based on ISA breeder recommendations. DS1 was formulated with reduction of 0.149% available P, 0.134% Ca, 55 kcal/kg AME, 0.33% CP, digestible amino acids (up to 0.015%) and 0.013% Na based on the contribution of Buttiauxella phytase at 300 FTU/kg. DS2 was formulated with reduction of 0.177% available P, 0.159% Ca, 60 kcal/kg AME, 0.61% CP, digestible amino acids (up to 0.028%) and 0.02% Na based on the contribution of Buttiauxella phytase at 600 FTU/kg. Every dietary treatment was fed to 12 cages containing 10 hens each. The trial treatments did not include a full, DS negative control, as ethical considerations regarding birds' welfare when feeding such diets over such an extended period of time did not permit this. No significant differences were seen in hen-day egg production, feed intake, egg weight, feed to egg mass ratio, shell, yolk or albumen proportion, unsaleable eggs or shell breaking strength in laying hens fed the PC diet or the DS diets with added phytase. Yolk colour increased significantly with phytase supplementation. Supplementing the DS1 diet with 300 FTU and the DS2 diet with 600 FTU resulted in non-significant differences in tibia ash, Ca and P, compared to the PC diet. The data from this study indicated that applying the nutrient contributions for Buttiauxella phytase at 300 and 600 FTU/kg maintained the egg production, BW and egg quality parameters compared to PC. The best economic efficiency value during the whole experimental period was recorded with phytase at 600 FTU/kg when full matrix values are used. When commercial diets are formulated based on ISA breeder recommendations, lowering diet nutrient density while supplementing with phytase reduced the overall diet cost, which should contribute to the profitability of egg production.

A total of 432, one-day-old broiler chickens were randomly assigned as a 2 × 4 factorial design (pellet or mash and 0, 25, 50, and 75% whole sorghum levels) in a completely randomised experiment, having six replicates with nine birds per replicate. Body weight and feed intake were measured on a pen basis at 10, 25, and 35 days of age and feed conversion ratio calculated. Pelleting diets significantly improved (P<0.05) feed intake, body weight and carcass yield of broiler chickens at 10 and 24 days of age. Heavier relative gizzard weights with lower pH (P<0.05) were recorded for broiler chickens offered mash diets at 35 days old. Feed conversion ratio at 35 days of age increased (P<0.035, quadratic effect) with higher levels of whole sorghum and levelled off at 75% inclusion rates. Relative gizzard weight at 35 days was marginally increased (P<0.033, linear effect) in line with rising sorghum levels. Similarly, relative bursa and liver weights at 35 days increased (P<0.037, quadratic effect and P<0.033, linear effect, respectively) with sorghum inclusion. The results showed that pelleted diets gave superior performance compared to mash diets. Although higher levels of sorghum inclusion in mash diets enhanced gizzard development, performance parameters of birds at 35 days of age were poorer, with 125 g less body weight and an increase in FCR from 1.51 to 1.62 for the 0% and 75% sorghum levels respectively.

Compensatory gain describes an accelerated growth seen in animals following a period of nutrient restriction. Methionine (Met) is the second limiting amino acid in typical swine diets and is essential for muscle growth. This study was conducted to determine (1) if a Met-deficient diet can cause growth retardation in growing pigs, (2) if returning to a normal feeding can yield compensatory gain in the pigs previously fed the Met-deficient diet, and (3) if this Met-deficiency followed by the normal feeding program affects carcass characteristics. Twenty individually-penned crossbred young barrows were randomly allotted to two dietary treatments (n = 10). One Met-deficient (D1) and one Met-adequate (D2) diets were formulated based on corn and soybean meal and fed to respective pigs for 31 days. After that, all pigs were fed the same commercial grower-finisher diet until market weight (around 125 kg), then slaughtered, and carcass characteristics measured. The D1 and D2 pigs began with similar body weights (23.5 vs. 23.6 kg; P = 0.935), but after 31-days on the dietary treatments, D1 pigs were lighter than D2 pigs (51.6 vs. 55.0 kg; P = 0.102). After feeding the normal diet for 55 days, D1 and D2 pigs had similar body weights (122.7 vs. 122.6 kg; P = 0.989). In terms of carcass characteristics, however, D1 pigs had thicker back-fat (at 10th rib; 2.95 vs. 2.51 cm; P = 0.015), heavier belly weight (11.0 vs. 9.6 kg; P = 0.005), lighter ham weights (untrimmed: 20.8 vs. 21.6 kg; P = 0.043; trimmed: 19.6 vs. 20.6 kg; P = 0.016), lighter picnic shoulder weight (8.72 vs. 9.80 kg; P = 0.041), lighter total lean cut weight (51.8 vs. 53.8 kg; P = 0.055), and lower lean cut percentage (56.4 vs. 59.0%; P = 0.012). These results indicate that the Met-deficient diet produced growth-retarded pigs, which showed compensatory gain after the normal feeding. At slaughter, the pigs previously fed the Met-deficient diet had more fat and less lean tissue than their non-deficient counterparts.

Dogs suffer from skin associated issues with a disproportionate frequency, with consequent interest in providing nutrition to optimize their skin's natural defences. Linoleic acid (LA) is known as an essential nutrient in dogs and plays a critical part in the lipid component of skin barrier formation. Minimum requirements have been defined, primarily based on eliminating signs of deficiencies such as dry, flaky skin and inflammation. Zn has been shown as an important nutrient for maintaining epidermal health. This pilot study investigated whether there are skin barrier benefits from feeding both linoleic acid and Zn at levels significantly in excess of published minimum requirements. Eight Labrador retrievers were fed a diet containing 3.8 g/Mcal LA, 21 mg/Mcal Zn for 12 weeks to establish baseline conditions for all dogs (basal diet). After this period, for a further 12 weeks, the dogs were switched onto a diet containing 7.9 g/Mcal LA and 50 mg/Mcal Zn (test diet). Transepidermal water loss (TEWL measurements) were used as a measure of skin quality and integrity and were taken at the end of the initial feeding period, and at 6 and 12 weeks of the test feeding period. TEWL was reduced by 8.11 g/m2/h (P < 0.001) six weeks after instigation of the test diet, and by 7.52 g/m2/h (P < 0.005) at 12 weeks, compared to the levels (14.73 g/m2/h) at the end of the basal feeding trial period. The results showed evidence of improved barrier properties as TEWL when feeding higher levels of LA and Zn for six and 12 weeks.