Qualitative feed restriction on productive performance and lipid metabolism in broiler chickens / Restrição alimentar qualitativa sobre o desempenho produtivo e o metabolismo lipídico em frango de corte

A trial was carried out to evaluate the effect of qualitative restriction at different rearing phases on liver fatness and plasma triglycerides without impairing the productive performance of broiler chickens. One hundred and seventy-six male chicks were randomly assigned to four treatments and reared in battery brooders (16 pens with 11 birds each) from 1 to 49-day-old. In the control group, chicks were fed a starter diet (1 to 28-day-old) with 3,300kcal ME/kg of diet and 22.5 percent CP; grower diet (29 to 42-day-old) 3,300kcal ME/kg of diet and 18.2 percent CP; and the finisher diet (43 to 49-day-old) 3,300kcal ME/kg and 18.2 percent CP. Three restrict groups were fed a low 2,800kcal ME/kg of diet and 24 percent CP from 7 to 14-day-old (treatment 1); from 7 to 21-day-old (treatment 2); and from 22 to 35-day-old (treatment 3). All treatments were fed control diet before and after the feed restriction period. Feed intake was not affected during the feed restriction period; nevertheless, weight gain was lower (P<0.05) for chicks fed restricted diet from 7 to 21 and from 21 to 35-day-old. At the end of each restriction period, scores of liver for fatty infiltration were higher in restricted birds compared to control birds, although no changes were detected in plasma triglyceride levels. On the 49th day of age, less intracellular fatty infiltration was observed in the liver of previously restricted birds compared to control birds, and weight gain was also lower in the restricted groups. Moreover, triglyceride plasma levels were similar among treatments, but decreased in 12-hour-fasted broilers compared to non-fasted birds. The low energy:protein ratio diet affected weight gain and fatty infiltration in the liver, but had no effect on plasma levels of triglycerides

Aplicou-se restrição alimentar qualitativa em frangos de corte, em diferentes fases do crescimento, para reduzir a infiltração gordurosa do fígado e os triglicerídeos plasmáticos, sem influir nas respostas produtivas. Distribuíram-se aleatoriamente 176 pintos machos em quatro tratamentos. As aves foram alojados em baterias (16 gaiolas com 11 aves cada) e foram criados de 1 a 49 dias de idade. No grupo controle as aves foram alimentadas com dieta inicial (1-28 dias) com 3.300kcal EM/kg/dieta e 22,5 por cento de proteína bruta (PB; dieta de crescimento (29-42 dias) com 3.300kcal EM/kg/dieta e 20,9 por cento de PB; dieta de acabamento (43-49 dias de idade) 3.300kcal EM/kg/dieta e 18,2 por cento de PB. As aves nos três grupos sob restrição foram alimentadas com dieta com 2.800kcal de EM/kg/dieta e 24 por cento de PB de 7 aos 14 dias de idade (tratamento 2), de 7 aos 21 dias de idade (tratamento 2) e de 22 aos 35 dias de idade (tratamento 3). Todas as aves dos tratamentos sob restrição foram alimentadas com a dieta controle antes e depois do período de restrição alimentar. Ao final de cada período de restrição foi observada uma maior infiltração gordurosa no fígado (representado pela composição química e escore histológico). Também não houve diferenças entre os triglicerídeos plasmáticos, quando comparado com o controle. Aos 49 dias de idade, o ganho de peso total e a infiltração gordurosa no fígado, foram menores nos grupos restritos. Os níveis de triglicérides plasmáticos, entretanto, foram semelhantes entre os tratamentos, mas reduziram nas aves com aplicação de jejum de 12 horas, quando comparados com aves sem jejum. A baixa relação energia/proteína da dieta afetou o ganho de peso e a infiltração gordurosa no fígado, mas não alterou os valores de triglicérides plasmáticos

Carcass characteristics of llamas (Lama glama) reared in Central Chile.

Body and carcass composition were studied on 10 male and 10 female naturally reared llamas (Lama glama). Half the animals were young (9-12 months) and the other half adult (>3 year). The average live weights for young and adult males were 104.4 and 100.6kg, and for females 67.6 and 104.6kg, respectively. Average carcass weights for the four groups were 58.9, 56.2, 36.8 and 56.7kg, respectively. Carcass composition for males and females was similar, but males had slightly higher dressing percentages than females (56.1 and 55.8 vs. 54.1 and 54.2 for young and adult males and females, respectively). Carcass length and fat depth at the loin and proportions of cuts in the carcass were similar for both the sexes, except for leg and tail, which were proportionately heavier in young females compared to the other groups. The composition of meat on fresh basis was: moisture 70.2%, protein 20.5%, ether extract 8.23% and ash 3.4%. Age and sex seemed to have no effects on the body and carcass characteristics studied nor on the chemical composition of meat.

Effect of energy/protein ratio on productive performance and carcass composition of male broilers.

To minimize excessive carcass fatness of broiler chicken, a diet with a low energy/protein ratio (EPR 117 resulting from 2800 Kcal ME/kg and 24% crude protein) was fed between days 7-14 (E1), 7-21 (E2) or 21-35 (E3); the rest of the time, up to 49 days of age, the chicks were fed as the control group, with EPR's of 138, 162 and 181 according to age. The results indicate that the feeding of a ration with a low EPR at different ages did not importantly impair productive performance although treatments E2 and E3 produced lower live weights and a decreased feed conversion (P less than or equal to 0.03). Concerning carcass characteristics, there was a trend to lower abdominal fat content in all experimental groups as compared to the control group and a lower ether extract content in the edible part of broilers from treatments E2 and E3 (P less than or equal to 0.06). More research is needed to find a metabolic explanation for these feeding effects.

[Chemical evaluation and determination of the nutritive value of a variety of Opaque-2 corn in the initial diet of broilers]. / Evaluación química y determinación del valor nutritivo de una variedad de maíz Opaco-2 en la ración inicial del broiler.

Chemical and amino acidic composition of Opaque-2 corn, cultivar CIMMYT-TL 81-A (Hungarian compound) locally produced were determined. In addition, the productive performance of broiler chicks fed Opaque-2 corn or normal corn (Pioneer) for the first 28 days of age was evaluated. The chemical and amino acid content results obtained for the Opaque-2 corn studied, compared well ranges previously reported. The productive performance at the end of the experiment was similar between the two treatments assayed.