ABSTRACT: This study was carried out to determine the combining effects of feeding up to 15 mg kg−1 ractopamine (RAC) to physically castrated (PC) pigs or those injected with an anti-GnRF vaccine (IC), on growth performance during suckling, weaning, growing and finishing phases. Out of a total of 1,160 male piglets, 50 % were surgically castrated at age 7, while 50 % underwent immunization against GnRF on the 103rd and 136th day of life. A completely randomized design, with two treatments (PC and IC), was used from the 1st until the 60th day of life. Afterwards, 792 animals, PC and IC, selected according to overall average weight (23.3 ± 0.69 kg) were allotted based on a completely randomized block design with a 2 × 4 factorial arrangement of treatments (castration categories × RAC levels) with 9 replications (11 animals) per main combination effect. IC growing pigs improved feed conversion due to lower average daily feed intake and higher average daily gain (ADG). During the finishing phase, both RAC and immunocastration increased body weight, but the effects were independent. RAC, on its own improved ADG and feed conversion. However, pigs fed 10 mg kg−1 RAC had higher blood lactate compared to those fed lower levels, suggesting that these animals were more susceptible to stress. Muscle depth was influenced only by RAC, whereas fat thickness was lower for IC. Lean meat increased and fat decreased in the shoulder and belly of IC; RAC had a positive effect on belly lean meat only. Either immunocastration or RAC inclusion (at least 5 mg kg−1) promoted muscle gain and fat reduction in pig carcass, adding value to pork.

O objetivo deste trabalho foi avaliar a eficiência do sistema de compostagem de dejetos e da aeração passiva no tratamento de resíduos da produção animal no município de Capão do Leão, no Rio Grande do Sul. Utilizou-se uma estrutura coberta com filme de polietileno de baixa densidade e aberta nas laterais, que recebeu seis caixas de plástico reforçado com fibra de vidro. O estudo foi realizado com dois tratamentos, os quais foram constituídos pela mistura de dejetos líquidos de bovinos leiteiros e maravalha, e de bovinos leiteiros e cama de aviário de dois lotes de frangos de corte. O SISCODE é eficiente na transformação dos resíduos líquidos em sólidos da produção animal, já que a alta umidade relativa e a baixa temperatura ambiente no município não afetam tal sistema de tratamento. A aeração passiva não é eficiente na evaporação do excedente de água e na oxigenação dos substratos compostados, não devendo ser utilizada na compostagem da mistura de resíduos líquidos e sólidos da produção animal.

A trial was conducted to evaluate the efficiency of composting of residues system and passive aeration for treating animal residues in Capão do Leão, in Rio Grande do Sul, Brazil. A low-density polythene film covered up a laterally opened structure was used. Such structure was to protect six plastic and glass fiber boxes. The study was carried out with two treatments, which were constituted by a mixture of liquid bovine residues and wood shaving; and a mixture of liquid bovine residues and poultry litter. SISCODE is efficient for transformation of the liquid in solid residues, given that local high-relative humidity and the low environmental temperature do not affect such residues treatment system. Passive aeration is not efficient for both evaporating excess of water and oxygenating composting substrates. Therefore, it should not be used for composting a mixture of liquid and solid residues from animal production.

Objetivou-se avaliar o efeito de suplementos contendo três combinações de energia e proteína sobre a produção leiteira, as características físico-químicas do leite, o peso e a condição corporal e o perfil bioquímico sanguíneo de vacas. Foram utilizadas 24 vacas lactantes em campo natural, distribuídas em delineamento completamente casualizado, recebendo um dos seguintes suplementos: baixos níveis de energia e proteína; baixo nível de energia e alto nível de proteína; ou altos níveis de energia e proteína. Em comparação ao suplemento com baixos níveis de energia e proteína, aquele com altos níveis de energia e proteína reduziu a instabilidade do leite na prova do álcool, aumentou em 50% a produção de leite e em 18% o escore de condição corporal das vacas. Além disso, ocasionou aumento dos componentes do leite e do perfil bioquímico sanguíneo das vacas: 13% no teor de lactose; 9% no de extrato seco desengordurado; 21% nos níveis plasmáticos de glicose; 24% no teor de fósforo; 16% no nível de creatinina; 9% no teor de magnésio; e reduziu em 40% o teor de nitrogênio ureico. O suplemento com altos níveis de energia e proteína foi mais eficiente que os demais em melhorar a estabilidade do leite na prova do álcool, o escore de condição corporal e os teores de alguns componentes químicos do leite e do sangue.

The aim of the study was to evaluate the effects of supplements with three combinations of energy and protein on milk production, milk physical and chemical characteristics, body weight, body condition score and blood biochemical profile of the cows. It was used, in this experiment, 24 lactating cows on natural fields distributed in a complete random design, receiving one of the following supplements: low levels of energy and protein, low level of energy and high level of protein or high levels of energy and protein. Compared to the low energy and protein supplement, high energy and protein supplement reduced milk instability in the alcohol test, it increased milk production in 50%, and body condition score of the cows in 18%. In addition, it increased milk components and blood biochemical profile of the cows: 13% in lactose content; 9% in non-fat dry extracts; 21% in glucose plasmatic levels, 24% in phosphorus content, 16% in creatinine content, 9% in magnesium contents; and it reduced ureic nitrogen in 40%. The supplement with high levels of energy and protein was more efficient than the others in improving milk stability in the alcohol test, body condition score and contents of some chemical components of the milk and of blood.