Suchergebnisse

The objective of this study was to evaluate the effects of diets supplemented with 0.0, 8.0, 16.0, and 24.0% distiller's dried grain solubles (DDGS) on nitrogen (N) intake, fecal and urinary N excretion, and N absorption and retention (N balance, NB) by feeding sheep. Four sheep of unidentified race were used, with an average body weight of 23.5 ± 1.5 kg, and housed in metabolism cages. We used a 4 × 4 Latin square design for the experimental design, and each experimental period lasted for 20 days. Data on N intake (NI), fecal N, urinary N, absorbed N, and NB were expressed in g day-1; percentage of NI and grams per kilogram of metabolic weight g (kg0.75)-1 were subjected to analysis of variance (ANOVA) and regression analysis at 5% probability. Inclusion of the different concentrations of DDGS in sheep diets had no effect on NI (mean of 15.11 g animal-1 day-1), nor on fecal and urinary N excretion (mean of 5.16 and 0.16 g animal-1 day-1, respectively). Moreover, DDGS supplementation did not alter NB or N absorption (mean of 9.79 and 9.95 g animal-1 day-1, respectively). Thus, it can be concluded that inclusion of up to 24% of DDGS in feed does not affect NI, fecal and urinary N excretion, and NB in sheep.

We evaluated the fractions of protein and carbohydrates in distillers dried grains with solubles (DDGS), corn grain (CG), soybean meal (SM), and corn silage (CS), as well as the in vitro digestibility (IVD) of DDGS, CG, SM, CS, rations containing 0.0, 8.0, 16.0, and 24.0% DDGS, and in vitro fermentation parameters after 24 h of incubation. DDGS were obtained following microbial fermentation for ethanol production from a sugar and alcohol distillery located in the state of Mato Grosso - Brazil. The Cornell Net Carbohydrate and Protein System (CNCPS) was used to determine the protein and carbohydrate fractions of experimental diets. For the in vitro nutrient digestion assay using the experimental foods and experimental diets, two sheep with an average body weight of 26 kg were used as inoculum donors. The in vitro digestibility of food and feed was assayed in three replicates. Fraction A of DDGS CP was 88, 71, and 37% lower in relation to fraction A of SM, CG, and CS, respectively. Fraction B2 of DDGS protein contained 21% CP, which represents 78.84% of DDGS protein in fraction B2, and is higher than the SM, which was 70.44%. The B3 fraction of CP, which is partly released during ruminal fermentation, was 18% lower for SM compared to DDGS, and is expressed in %CP. For carbohydrate fractionation, the DDGS presented 8.64% for the A + B1 fraction on a DM basis, which was 62, 86, and 74% lower compared to those obtained for SM, CG. and CS, respectively. The hemicellulose and cellulose contents of DDGS were higher than those of SM, as verified in fraction B2, with a value of 46.92%, expressed in DM. The in vitro digestibility coefficients (IVDC) of the DDGS nutrients did not differ (p > 0.05) in relation to those of the other experimental foods. The inclusion of DDGS in rations formulated for sheep did not change (p > 0.05) the IVDC of DM, OM, CP. NDF, or ADF, with mean values of 70.93, 70.64, 59.58, 52.83, and 43.40%, respectively. Therefore, DDGS comprise a protein-rich food containing more than 70% CP in fraction B2, with a large amount of carbohydrates bound to the cell wall. In addition, DDGS possess a similar digestibility coefficient to corn grain and soybean meal; however, up to 24% can be included in feed formulations for ruminants without changing the in vitro digestibility coefficient of nutrients.

This study aimed to evaluate the inclusion of 0.0%, 0.4%, 0.8%, and 1.2% slow release urea (SRU) in sheep feed on the intake and total digestibility coefficient (DC) of nutrients and ruminal parameters of sheep living in tropical regions. Four sheep with a body weight (BW) average of 30.8 ± 1.7 kg were assigned to a Latin square design. The animals were placed in metabolic cages and received two meals a day. Intake data and DC of nutrients of the sheep were subjected to analysis of variance and differences were tested using a regression equation to 5% probability. The inclusion of 0.0%, 0.4%, 0.8%, and 1.2% SRU in sheep feed did not change (p > 0.05) the intake of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral or acid detergent fiber (NDF, ADF), total carbohydrates (TC), and non-fibrous carbohydrate (NFC) expressed in g animal-1 day-1, g (kg0.75)-1, and % BW. The mean values of 3.04%, 2.82%, 0.41%, 0.07%, 1.36%, 0.87%, 2.31%, and 1.00% of BW were obtained for the intake of DM, OM, CP, EE, ANF, ADF, TC, and NFC, respectively. The inclusion of 0.0%, 0.4%, 0.8%, and 1.2% of SRU in sheep rations had a quadratic manner (p < 0.05) the DC of DM and CP, with maximum values of 69.67% and 63.59%, respectively, for 0.51% and 0.66% levels of SRU inclusion in the experimental diets. The pH of the rumen fluid did not vary (p > 0.05) for different levels of inclusion of SRU in the feed. However, the pH of the rumen fluid did differ (p < 0.05) in relation to time (T) after feeding for all experimental diets. The inclusion levels of SRU in sheep feed did not affect (p > 0.05) the concentration of ammonia nitrogen (NH3-N) of the rumen fluid, but there was a quadratic effect (p < 0.05) with relation to T for all experimental diets. Thus, we conclude that the inclusion of 0.66% SRU provides the best digestibility value of CP and is the appropriate value for the digestion of DM. The inclusion of up to 1.2% of SRU in sheep rations did not change the intake of nutrients and ruminal parameters.