No abstract

The effect of nitrogen (N) fertilization on the dry-matter (DM) yield and nutritional value of sorghum (Sorghum sp., cv. Jumbo) and black oat (Avena strigosa cv., IPR 61) was investigated in the context of forage and livestock production in southern Brazil. Sorghum was cultivated with 0, 37Á5, 75, 150, 225, 300 and 375 kg N ha À1 during the summer crop seasons of 2010/11 and 2011/12. Black oat received 0, 40, 80, 120, 160, 200 and 240 kg N ha À1 in the winter of 2011. According to the adjusted polynomial regression, sorghum DM yield increased in response to N up to 288 (12Á9 t ha À1 ) and 264 kg ha À1 (5Á6 t ha À1 ) in 2010/11 and 2011/12 respectively. Crude protein (CP) content of sorghum was highest at 349 and 328 kg N ha À1 , but in vitro drymatter digestibility (IVDMD) was highest at 212-207 kg N ha À1 in 2010/11 and 2011/12 respectively. Sorghum neutral detergent fibre (NDF) and acid detergent fibre (ADF) were not affected by N fertilization. In black oat, the maximum DM yield (6Á0 t ha À1 ) was obtained with 187 kg N ha À1 ; the IVDMD, NDF and ADF were not affected by N fertilization, but the CP content increased up to 220 kg N ha À1 . It is concluded that these forage species can improve the year-to-year amount and quality of forage produced but high rates of N fertilizer are required to achieve high yields. Fertilizer N rates of 210-280 kg N ha À1 in sorghum and 180 kg N ha À1 in black oat in the crop rotation provide the greatest responses in DM yield consistent with good nutritional quality for livestock production.

This experiment was carried out in a 104 m² poultry house located between the geographical coordinates 25°45'00" south latitude and 53°03'25" west longitude and an average altitude of 550 m, from September to November, 2008. The chickens were placed in 12 pens measuring 2 m² each at a stocking density of 12 chickens m-2. This study aimed at evaluating the effect of two different initial weights (chick weight on first day of experiment) and two types of litter material on broiler production parameters, litter humidity, as well as on breast and footpad lesions. A total of 240 female Cobb® chickens, derived from the same flock of breeders, was distributed in a completely randomized experimental design with a 2 (initial weight) by 2 (litter material) factorial arrangement with three replicates per treatment. Initial weights were classified as light (34.40 - 35.22 g) or heavy (39.29 - 41.30 g), whereas wood shavings and sawdust were used as litter material. Data were analyzed by ANOVA and means were compared by Tukey's test at 95% confidence level. Initial weight significantly influenced bird performance, as chickens with heavy initial weight presented higher feed intake and body weight. Type of litter did not have any effect on breast injuries and litter humidity. However, the wood shavings litter significantly influenced footpad lesions

The objectives of this study were: 1) to compare the effects of live yeast (LY), yeast fermentation product (YFP), a mix of Lactobacillus acidophilus and Propionibacterium freudenreichii (MLP), and Lactobacillus plantarum included as additives in dairy cows’ diets on in vitro ruminal fermentation and gas production (GP); and 2) to evaluate the effects of L. plantarum as direct-fed microbials (DFM) in dairy cows’ diets on in vitro ruminal fermentation, GP, nutrient digestibility, and N metabolism. Three experiments were carried out: Exp. 1 had the objective to compare all additives regarding ruminal fermentation parameters: an Ankom GP system was used in a completely randomized design, consisting of four 48 h incubations, and eight replications per treatment. There were eight treatments: a basal diet without additive (CTRL) or with one of the following additives: LY, YFP, MLP, or L. plantarum at four levels (% of diet Dry Matter (DM)): 0.05% (L1), 0.10% (L2), 0.15% (L3), and 0.20% (L4). In Exp. 2, a batch culture was used to evaluate ruminal fermentation, and CO2 and CH4 production using the same treatments and a similar experimental design, except for having 16 replications per treatment. Based on Exp. 1 and 2 results, Exp. 3 aimed at evaluating the effects of the L. plantarum on ruminal true nutrient digestibility and N utilization in order to evaluate the use of L. plantarum as DFM. The treatments CTRL, MLP, L1, and L2 were used in a replicated 4 × 4 Latin square design using a dual-flow continuous culture system. Data were analyzed using linear and nonlinear regression; treatment means were compared through contrasts, and L treatments in Exp. 1 and 2 were tested for linear, quadratic, and cubic effects. In Exp. 1, all treatments containing additives tended to reduce OM digestibility as well as reduced total volatile fatty acids (VFA) concentration and total GP. The YFP had greater OM digestibility than LY, and MLP treatment had greater total VFA concentration compared to L. plantarum treatments. In Exp. 2, additives reduced CO2 production, and there were no major differences in CH4. In Exp. 3, all additives reduced NH3-N concentration. In conclusion, pH and lactate concentration were not affected in all three experiments regardless of additive tested, suggesting that these additives may not improve ruminal fermentation by pH modulation; and L. plantarum may improve ruminal N metabolism when used as DFM in high-producing dairy cows’ diets, mainly by reducing NH3-N concentration.

No abstract

ResumoRealizou-se este trabalho com o objetivo de avaliar o desempenho produtivo e o rendimento de carcaça de diferentes linhagens e sexagens de frangos de corte. Foram avaliadas 576 aves das linhagens Cobb, Ross e Hubbard, dispostas nas sexagem macho, fêmea ou misto, abatidas aos 45 dias de idade. Utilizou-se o delineamento inteiramente casualizado (DIC), num bifatorial 3 x 3 (linhagens x sexagem), com quatro repetições e 16 aves em cada tratamento. O peso vivo, ganho de peso, consumo de ração e conversão alimentar apresentaram diferenças significativas no decorrer das fases avaliadas, porém, mostraram-se semelhantes ao final do período avaliado. O desempenho dos machos apresentou superioridade em comparação com as fêmeas e os mistos. No rendimento de carcaça, não foi possível observar diferenças significativas entre as linhagens e sexagens das aves; no entanto, em alguns cortes nobres a linhagens Cobb apresentou melhores resultados. Palavras-chave: avicultura; genética; mercado consumidor; tecnologia. Abstract:We carried out this study to evaluate the productive performance and carcass yield of different strains and sexing of broilers. We evaluated 576 birds of Cobb, Ross, and Hubbard strains, arranged in male, female or mixed sexing, slaughtered at 45 days of age. We used a completely randomized design (CRD), in a 3 X 3 factorial (strain X sex), with four replicates per treatment. Body weight, weight gain, feed intake, and feed conversion showed significant differences in the course of the phases evaluated; however, they were similar at the end of the study period. Males showed superior results compared to females and mixed sexing. Carcass yield showed no significant differences among strains and sexing of birds; however, in some prime cuts, Cobb presented the best results.

No abstract

Undesirable interactions between trace mineral elements and ruminal contents may occur during digestion when mineral salts are supplemented. Antimicrobial effects of copper sulfate (CuSO 4 ) may affect ruminal digestibility of nutrients when fed as a source of copper (Cu), while sodium selenite (Na 2 SeO 3 ) may be reduced in the rumen to less available forms of selenium (Se). Our objective was to evaluate if protection of CuSO 4 and Na 2 SeO 3 by lipid-microencapsulation would induce changes on ruminal microbial fermentation. We used 8 fermentors in a dual-flow continuous-culture system in a 4 × 4 duplicated Latin square with a 2 × 2 factorial arrangement of treatments. Factors were CuSO 4 protection (unprotected and protected by lipid-microencapsulation) and Na 2 SeO 3 protection (unprotected and protected by lipid-microencapsulation). Treatments consisted of supplementation with 15 mg/kg of Cu and 0.3 mg/kg of Se from either unprotected or protected (lipid-microencapsulated) sources, as follows: (1) Control (unprotected CuSO 4 + unprotected Na 2 SeO 3 ); (2) Cu-P (protected CuSO 4 + unprotected Na 2 SeO 3 ); (3) Se-P (unprotected CuSO 4 + protected Na 2 SeO 3 ); (4) (Cu+Se)-P (protected CuSO 4 + protected Na 2 SeO 3 ). All diets had the same nutrient composition and fermentors were fed 106 g of dry matter/d. Each experimental period was 10 d (7 d of adaptation and 3 d for sample collections). Daily pooled samples of effluents were analyzed for pH, NH 3 -N, nutrient digestibility, and flows (g/d) of total N, NH 3 -N, nonammonia N (NAN), bacterial N, dietary N, and bacterial efficiency. Kinetics of volatile fatty acids was analyzed in samples collected daily at 0, 1, 2, 4, 6, and 8 h after feeding. Main effects of Cu protection, Se protection, and their interaction were tested for all response variables. Kinetics data were analyzed as repeated measures. Protection of Cu decreased acetate molar proportion, increased butyrate proportion, and tended to decrease acetate: propionate ratio in samples of kinetics, but did not modify nutrient digestibility. Protection of Se tended to decrease NH 3 -N concentration, NH 3 -N flow, and CP digestibility; and to increase flows of nonammonia N and dietary N. Our results indicate that protection of CuSO 4 may increase butyrate concentration at expenses of acetate, while protection of Na 2 SeO 3 tended to reduce ruminal degradation of N. Further research is needed to determine the effects of lipid-microencapsulation on intestinal absorption, tissue distribution of Cu and Se, and animal performance.