The objective of this work was to evaluate the precision of Artificial Neural Networks (ANNs) to estimate zootechnical indexes, based on thermal and physiological variables of pregnant sows. This study was carried out from January to April 2005, in a swine industrial production farm in the gestation section with 27 primiparous gilts, allocated in individual pens and after on farrowing pens where it was quantified animal production indexes of piglets from the study. Therefore, an ANN backpropagation was implemented, with […]

The objective of the present study was to evaluate the performance of beef cattle in feedlots fed diets containing either whole-crop maize silage or sugarcane silage, and with different formulations. Five diets were evaluated: MSF – diet containing whole-crop maize silage, with fixed formulation during feedlot period; MSV- diet containing whole-crop maize silage, with variable formulation according to feedlot phase; SCSF – diet containing sugarcane silage with fixed formulation; SCSV- diet containing sugarcane silage, with variable formulation; SCSV/MSV- SCSV diet […]

The objective of this experiment was to evaluate the growth, performance and size of viscera of Santa Inês lambs after compensatory gain. Twenty-two animals, with two ranges of initial body weights, light (33.5 kg) and heavy (56.8 kg), were allotted to one of the three diets: control, fed ad libitum; nutritional restriction, fed to maintain body weight; and compensatory growth with feed restriction and then fed without restriction up to body weight similar to control animals, when they were slaughtered. […]

It was studied the effects of shading (0, 36 and 54%) and of four nitrogen doses (0, 50, 100 and 150 mg N/dm3 of soil) on the morphogenetic traits and on the tillering of grasses of Brachiaria genus (B. decumbens, B. ruziziensis and B. brizantha cv. Marandu and cv. Xaraes), cultivated in pots with 5 kg substrate. It was used a complete random design, in a 3 × 4 × 4 factorial scheme with three replications. Nitrogen promoted increase in […]

This study was conducted to determine optimum test duration for measuring performance, feed intake and feed efficiency. Sixty young Nellore bulls were submitted to feeding performance test and fed in individual pens to determine feed intake and performance over 112 days. Body weight was determined every 28 days, after fasting of water and feed for 16 hours. Changes in variance, relative variance and Pearson and Spearman correlations among data from shortened test periods (28, 56 and 84 days) and full […]

It was studied performance, behavior and forage ingestion by beef heifers on pearl millet (Pennisetum americanum (L.) Leeke) and Alexander grass (Urochloa plantaginea) pastures from January to April 2008. The continuous grazing method with a variable number of animals was used. Forage ingestion was estimated during vegetative and reproductive stage of forage plants using chromic oxide as fecal production marker. Evaluations of behavior were carried out by visual observation in four 24-hour continuous periods. Mean values of forage mass, forage […]

The objective of this work was to evaluate the effects of sodium levels in the diet for the growing phase on the performance of Japanese quails during the the growth and production phases. It was used 480 quails at 1 day of age distributed in a completely randomized design with six diets containing 0.07; 0.12; 0.17; 0.22; 0.27 and 0.32% of sodium, evaluated with eight repetitions of ten birds per experimental unit. In the phase from 1 to 21 days […]

It was evaluated statistical models with different assumptions to define the one that best describes the presence of genotype × environment interaction on adjusted post-weaning weight gain (PWG345) of Hereford cattle, through the study of reactions norms to the environment, obtained by random regression using a Bayesian approach. Four reaction norms hierarchical models (RNHM) were used through the INTERGEN program. The RNHMK uses the solutions of contemporary groups previously estimated by the standard animal model (AM) and considers them as […]

It was evaluated the effects of levels of digestible lysine and chelate zinc combined in the diet for laying on the egg quality. It was used 720 birds, from 48 to 60 weeks of age, distributed in a completely randomized design in a 3 × 5 factorial scheme with three levels of zinc and five levels of lysine, applied into six replicates in the experimental units of eight birds per plot. The levels were: 137, 309 and 655 ppm zinc […]

It was evaluated the bioeconomic impact of the breeding soundness evaluation on beef cattle production in southern Brazil. Two similar production systems, with and without the use of breeding soundness evaluation, were compared during 4 years in the municipality of Júlio e Castilhos. The rate of unsound bulls in the first examination was 22.8%. By performing the examination, calf production increased by 31%, 13.8 calves/bull/year and 24 kg of calves/cow/year. The benefit/cost ratio on the investment with the breeding soundness […]