Digestibility and nutritional parameters of maize ethanol coproducts and xylanase for broiler diets.

1. The objective of this study was to determine the nutritional and energy values of four maize distiller's dried grains with solubles (DDGS) and one maize high protein distiller's dried grains (HP-DDG) from ethanol production plants in Brazil; to evaluate the digestibility, performance, nitrogen balance and energy values for broiler chickens fed diets containing these coproducts (Experiment I); and to evaluate the effects of xylanase inclusion in diets containing maize DDGS for broilers on energy availability, digestibility, nitrogen balance and gastrointestinal morphometry (Experiment II).2. For each experiment, 180 broiler chickens aged 17 and 30 days with initial weights of 450 ± 18 g and 1228 ± 33 g, respectively, were used; the chickens were distributed into 36 metabolism cages. The experimental design consisted of complete randomised blocks, with six replications per treatment and five birds per experimental unit. The treatments consisted of a basal diet (BD) and five test diets containing maize ethanol coproducts (Experiment I) one BD and five test diets containing DDGS with inclusions of 0, 8,000, 16,000, 24,000 and 32,000 BXU/kg xylanase (Experiment II). In Experiment I, HP-DDG and DDGS2 presented higher AME and AMEn values (14.1 and 13.9 MJ/kg and 13.4 and 13.3 MJ/kg, respectively), than did the other coproducts (p < 0.05). Compared with DDGS1 and DDGS3, DDGS4 and HP-DDG had higher digestible CP values (p < 0.05). In Experiment II, the inclusion of the enzyme quadratically affected the values of digestible CP and digestible EE (p < 0.05), with the maximum values occurring with the inclusion of 18 750 and 22,170 BXU/kg of xylanase, respectively.3. The digestible NDF and digestible MM values linearly increased with the inclusion of xylanase (p < 0.05). The addition of xylanase had no effect on gastrointestinal morphometry (p > 0.05). It was concluded that the inclusion of between 18,000 and 22,000 BXU/kg of xylanase resulted in better digestible CP and digestible EE values.

Dietary high-protein distiller's dried grains with solubles can fully replace soybean meal in diets for meat quails without affecting growth performance.

1. The purpose of this study was to determine the metabolisable energy of high-protein distiller's dried grains with solubles (HP-DDGS) for meat quail (Coturnix coturnix coturnix; Experiment I) and evaluate the effects of dietary levels of HP-DDGS on animal performance, carcase characteristics, meat quality, and organ weights (Experiment II).2. In Experiment 1, 96 meat quail were distributed in a completely randomised design with two treatments (reference or test diet) and six replicates of eight birds. The experimental period consisted of 5 d adaptation, followed by 5 d total excreta collection. The experimental diets consisted of a reference (control) and a test diet formulated with 800 g/kg reference diet and 200 g/kg HP-DDGS.3. In Experiment 2, 612 meat quail were distributed in a completely randomised design fed one of six dietary levels of HP-DDGS (0, 85, 170, 255, 340, or 425 g/kg) as a replacement for soybean meal. At 42 d of age, birds were slaughtered and evaluated for carcase yield, organ weights, and meat quality.4. Apparent metabolisable energy values corrected for nitrogen retention of HP-DDGS were 12.5 and 12.3 MJ/kg for males and females, respectively.5. In the starter phase (1-21 d of age), increasing dietary HP-DDGS levels had a quadratic effect on body weight (BW) (P = 0.020) and body weight gain (BWG) (P = 0.019). The maximum BW and BWG values were estimated to be achieved with 296.0 and 296.2 g/kg dietary HP-DDGS, respectively. Overall (1-42 d of age), increasing dietary HP-DDGS levels in replacement of soybean meal did not affect animal performance, carcase yield, meat quality or organ weight in meat quail.6. It was concluded that dietary HP-DDGS can fully replace soybean meal in meat quail diets without affecting growth performance, carcase yield, meat quality or organ weight.

Time-response relationship of ractopamine feeding on growth performance, plasma urea nitrogen concentration, and carcass traits of finishing pigs.

Ractopamine hydrochloride (RAC) improves swine production efficiency by redirecting nutrients to favor muscle accretion rather than fat deposition. In the present study, the time-dependent effect of RAC feeding on performance, plasma urea N (PUN) concentrations, and carcass traits of finishing pigs were evaluated. In a 28-d growth study, 80 barrows (average initial BW = 69.4 ± 7.9 kg) were assigned to 1 of 5 treatments in a randomized complete block design with 8 replicate pens per treatment and 2 pigs per pen. The pigs were fed a corn-soybean meal-based diet with no added RAC (control) or 10 mg of RAC/kg fed for 7, 14, 21, or 28 d before slaughter. All diets were formulated to contain 0.88% standardized ileal digestible Lys (1.0% total Lys) and 3.23 Mcal of ME/kg. Individual pig BW and pen feed disappearance were recorded weekly to determine BW changes, ADG, ADFI, and G:F. Anterior vena cava blood samples were taken on d 28 for determination of PUN concentrations. After 28 d on trial, the pigs were slaughtered and carcass measurements made at 24 h postmortem. Overall, providing pigs with different RAC feeding durations did not affect the final BW and ADFI but resulted in a tendency (P = 0.09) for a linear increase in ADG and a linear improvement (P = 0.003) in G:F. No effect of RAC feeding was found for weekly ADFI. Weekly improvements (P < 0.05) in ADG and G:F were observed over the first 21 d of RAC feeding. However, the growth response declined (P < 0.05) in wk 4 of RAC treatment. The concentrations of PUN exhibited a quadratic decrease (P = 0.004) as the RAC feeding duration increased. Although RAC feeding did not affect any backfat measurements and carcass length, increasing the RAC feeding duration linearly increased HCW (P = 0.01), dressing percentage (P = 0.03), LM depth (P = 0.001), LM area (P < 0.001), muscle-to-fat ratio (P = 0.004), and predicted carcass lean percentage (P = 0.02). These results indicate that a greater growth rate was achieved within the first 21 d of RAC feeding whereas the magnitude of carcass response was directly dependent on the duration of RAC feeding.