Material de cama: qualidade, quantidade e efeito sobre o desempenho de frangos de corte

An experiment was conducted to evaluate performance, mortality and incidence of lesions on the breasts, hooks and foot pads of broilers raised on wood-scrap litter, rice hulls, Brachiaria hey (Brachiaria decumbens), Napier hay (Pennisetum purpureum) and Coast-cross hay (Cynodon dactylon). A randomized experimental design with five litters, two sexes, four replications and fifty birds per box was used. A standard litter height of 5 cm of wood-scraps and a weight of 20 250 g were adopted as criteria for use of other materials in the boxes. The amount of excreta deposited was 1697 g per raised bird (34,00 % of feed consumption). The incidence of lesions was evaluated in five birds per box after 35, 42 and 49 days and after slaughter. The criteria for scoring lesions were: 0 = without lesion; 1 = inflammation; 2 = mild ulceration; 3 = severe ulceration. At the end of experimental period (49 days) no differences were observed For weight, weight gain, feed consumption, feed/gain ratio and mortality among treatments. The lesions of the hocks and foot pads of the birds, raised on either Coast-cross hay and Napier hay, were more severe than those on wood-scraps and Brachiaria hay. Males showed better performance than females, but their hock lesions were more severe, independent of the litter used. Based on the performance and lesions scores, it was concluded that Braquiaria hay could be used as litter in replace wood-scraps and rice bulls.

Estudo do balanço nitrogenado e da digestibilidade da matéria seca e proteína de rações, para ovinos, suplementadas com amiréia, uréia ou farelo de algodão

To evaluate the nutritional value of rations supplemented with different protein sources, an in vivo digestibility trial was conducted to determine the coefficients of digestibility for dry matter (DMDC) and crude protein (CPDC), nitrogen balance (NB) and the fecal non-protein nitrogen (NPN). Twenty - four 11-months - old lambs weighing 30.4 +/- 3.0 kg were blocked on the basis of their body weight and randomly allocated to three treatments groups; suplemented with cottonseed meal (CSM), starea (ST) or urea (UR). The DMDC was statistically superior for the Starea treatment (67.7%) over the others (64.3% and 64.1% for CSM and UR). The CSM, UR and ST rations had no influence on CPDC (63.9; 66.9 and 69.4%, respectively) and on fecal NPN (1,3; 1,2 e 1,3 g/day, respectively). The NB results were similar also among treatments (13,4; 9,0 e 10,5 g/day to CSM, UR and ST, respectively) although the ST treatment lambs excreted larger amounts of nitrogen in the urine (7.7 g/day) in relation to CSM (4.8g/day) and similar to UR treatment (6.5 g/day). Starea supplement in ruminant diets increased dry matter digestibility when compared to cottonseed meal and urea, but did not improve the efficiency of the nitrogen utilization by lambs.

Sistemas de Alimentação com Livre Escolha e Semi Livre Escolha para Poedeiras

This research was carried out to verify the ability of laying hens to select food in order to meet their requirements for protein and energy. Ninety-six Hy-Line White laying hens, 45 weeks old, were allotted to a randomized block design with two blocks (two ranges of body weight), four treatments, and three replicates of four hens in each block. The treatments consisted of four different feeding systems: I-Conventional feeding represented by a complete ration composed of 60% ground corn and 40% protein concentrate; 2-Free-choice feeding with ground corn, protein concentrate and oyster shells fed in feeders with three separate compartments; 3-Semi free-choice feeding with whole corn grain, protein concentrate and oyster shells in the same proportion in one feeder; 4-Free-choice feeding with whole corn grain, protein concentrate and oyster shells fed in feeders with three separate compartments. The results indicated that the hens, in spite of age, adapt to different feeding systems, and that they can select feed to meet their nutrient requirements. The semi free-choice and free-choice feeding systems with whole corn grain resulted in the same performance compared to conventional feeding, but shell quality was not improved by oyster shell supplementation. However, the worst performance was with free-choice feeding with ground corn, which indicated that in the free-choice feeding system the use of whole corn grain is recommended.

Avaliação das Sub-Frações dos Carboidratos e das Proteinas, Usando as Metodologias do Cncps e In situ com Bovinos da Raça Nelore. 1. Silagem de Milho

To validate the use of the Cornell Net Carbohydrate and Protein System (CNCPS) under Brazilian conditions, the chemical composition, the potential and the effective degradabilities of the carbohydrate and protein subfractions, and the solid phase passage rate were determined for corn silage in diets with forage:concentrate ratios of 80:20 (DI) and 60:40 (D2) using Nellore cattle. The chromium mordant technique was used to determine the particulate passage rate of solids. For diet 2, there was a reduction in the potentially degradable dry matter (DM), and however not significant, a reduction in the degradation rates of neutral detergent Fiber (NDF, 49%) and neutral detergent insoluble nitrogen (NDIN, 32%), and an increase in the degradation rare of starch (ST, 25%). The use of lag time increased the effective DM degradation (EDDM) of corn silage in both diets (23% and 53% for D1 and D2, respectively). The concentrate ratios did not influence the particulate passage rate of the diets. The higher values related ro the availability of the protein subfractions may indicate a underestimation by CNCPS, Rnd(or) could be attributed to the Zebu animals used in this study.

Analysis of beef cattle longitudinal data applying a nonlinear model

The objective of this work was to evaluate the Nelore beef cattle, growth curve parameters using the Von Bertalanffy function in a nested Bayesian procedure that allowed estimation of the joint posterior distribution of growth curve parameters, their (co)variance components, and the environmental and additive genetic components affecting them. A hierarchical model was applied; each individual had a growth trajectory described by the nonlinear function, and each parameter of this function was considered to be affected by genetic and environmental effects that were described by an animal model. Random samples of the posterior distributions were drawn using Gibbs sampling and Metropolis-Hastings algorithms. The data set consisted of a total of 145,961 BW recorded from 15,386 animals. Even though the curve parameters were estimated for animals with few records, given that the information from related animals and the structure of systematic effects were considered in the curve fitting, all mature BW predicted were suitable. A large additive genetic variance for mature BW was observed. The parameter a of growth curves, which represents asymptotic adult BW, could be used as a selection criterion to control increases in adult BW when selecting for growth rate. The effect of maternal environment on growth was carried through to maturity and should be considered when evaluating adult BW. Other growth curve parameters showed small additive genetic and maternal effects. Mature BW and parameter k, related to the slope of the curve, presented a large, positive genetic correlation. The results indicated that selection for growth rate would increase adult BW without substantially changing the shape of the growth curve. Selection to change the slope of the growth curve without modifying adult BW would be inefficient because their genetic correlation is large. However, adult BW could be considered in a selection index with its corresponding economic weight to improve the overall efficiency of beef cattle production.

Digestão total e pré-cecal dos nutrientes em potros fistulados no íleo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos da amonização sobre a ocorrência de fungos, composição química e digestibilidade in vitro de fenos de grama Seda (Cynodon dactylon (L.) Pers.)

The experiment was conducted with grama seda (Cynodon dactylon (L.) Pers.) hays stored with a low moisture content (12-15%) and without chemical treatment, and hays stored with a high moisture content (20-25%) and treated with anhydrous ammonia (NH3) al 0.5 and 1.0% of DM, and urea at 0.9 and 1.8% of DM. At 65 days after treatment (AT) under a plastic cover, the bales were opened and samples were taken at 3, 15 and 30 days to determine the chemical composition and in vitro digestibility (IVDMD) of the hays. For the identification of fungi, samples were taken at 0, 15 and 30 days AT. The data were analyzed according to a split-plot design with the effects of the chemical treatments studied in the main plot and the effects of the periods of post-treatment studied in the sub-plots, Fourteen genera of fungi were observed in the hays, not treated and treated with NH3 and urea, with a higher occurrence of Cladosporium, Curvularia, Aspergillus, and Penicillium. Treatment with anhydrous ammonia and 1.8% urea controlled the occurrence of Aspergillus; however, Penicillium decreased in hays treated with ammonia 30 days AT. Ammoniation did not influence the contents of ADF, cellulose and lignin in the hays, but NDF and hemicellulose decreased with the use of ammonia 30 days AT. The CP contents and the IVDMD increased with ammoniation. The CP contents decreased in hays treated with NH3 as days AT increase, while hays treated with urea did not change.

Genetic evaluation of the probability of pregnancy at 14 months for Nellore heifers

To estimate the heritability for the probability that yearling heifers would become pregnant, we analyzed the records of 11,487 Nellore animals that participated in breeding seasons at three farms in the Brazilian states of São Paulo and Mato Grosso do Sul. All heifers were exposed to a bull at the age of about 14 mo. The probability of pregnancy was analyzed as a categorical trait, with a value of 1 (success) assigned to heifers that were diagnosed pregnant by rectal palpation about 60 d after the end of the breeding season of 90 d and a value of 0 (failure) assigned to those that were not pregnant at that time. The estimate of heritability, obtained by Method 9, was 0.57 with standard error of 0.01. The EPD was predicted using a maximum a posteriori threshold method and was expressed as deviations from 50% probability. The range in EPD was -24.50 to 24.55%, with a mean of 0.78% and a SD of 7.46%. We conclude that EPD for probability of pregnancy can be used to select heifers with a higher probability of being fertile. However, it is mainly recommended for the selection of bulls for the production of precocious daughters because the accuracy of prediction is higher for bulls, depending on their number of daughters.

Sojas integrais tostada pelo vapor e extrusada em rações de poedeiras

An experiment with 400 laying hens Hy Line with 26 weeks of age was conducted to compare the performance of laying hens fed during four cycles of 28 days with diets containing soybean meal (SM) plus soybean oil (SBM+oil), whole extruded soybean (ESB) and whole steam toasted soybean (TSB). A completely design randomized blocks was used, with 10 treatments and five replicates and eight laying hens in each experimental unit. The treatments consisted on the replacement of SBM per ESB and TSB at the levels 0, 25, 50, 75 and 100%; and as control the SBM with or without addition of oil. The results obtained showed that the hens were able to regulate the feed intake to maintain the energy intake only at lower energetic levels, however they tended to over intake energy with the increase of energy levels of the diets. The addition of oil or soybeans in the diets improved feed: gain ratio, however worsened the energy efficiency in relation to the diet without oil. The processing of soybean provided differences on the performance of laying hens and the ESB showed to be superior to TSB. The hens had higher use of the oil added to the soybean meal (SBM + oil) and ESB in relation to TSB. However, the values of AMEn obtained for the ESB were 12% higher, in average, to those determined for the SBM + oil and for the TSB.

Evaluation of whole toasted and extruded soybean on the performance of broilers

This experiment was conducted to compare the performance of 1260 chicks fed diets containing soybean meal plus soybean oil (SBM + oil), whole extruded soybean (ESB) and whole steam toasted soybean (TSB), with two protein levels. A complete randomized design was used, with six treatments and 3 replicates of each sex. The treatments consisted of a factorial arrangement 2 x 3 x 2 to test three soybean types (SBM + oil, ESB and TSB), two protein levels (optimum and suboptimum) and two sexes. From 1 to 49 days of age, the tested soybean types did not affect the diet intake. However, ESB provided higher weight gain in relation to SBM + oil, but it did not differ from TSB. The feed:gain ratio obtained with ESB and TSB was better in relation to SBM + oil. There was no difference between the nutritional value of TSB and ESB, because they provided similar performance to the birds.