Oilseeds in diets of fattening lambs

Abstract

An experiment was conducted to compare different oilseeds in replacement of ground corn in diets of fattening lambs, evaluating performance, apparent diet digestibility, ingestive behavior, and carcass traits. Twenty-four crossbred lambs, three months old and with initial body weight 25.97 ± 0.75 kg, were kept in individual pens. The animals received one of the following diets: 'control' (no oilseeds, 3.11% Ether Extract -EE), 'cottonseed' (6.14% EE), 'sunflower' (6.33% EE), and 'soybean' (6.30% EE). All diets contained 23.63% of coast cross hay and 76.37% of concentrate. After 84 days in feedlot, the animals were slaughtered and the carcasses were evaluated. The dry matter intake (DMI) and daily weight gain (DWG) of animals fed with the control diet was higher than sunflower (P≤0.05). Final body weight and carcass weight were higher (P≤0.05) in the control (42.42 kg and 19.27 kg, respectively) than for sunflower diet (34.85 kg and 16.05 kg, respectively). Neutral detergent fiber (NDF) digestibility was reduced (P≤0.05) when the animals received cottonseed diet (50.34%) in comparison to soybean (71.07%), sunflower (67.07%) and control (66.50%). NDF digestibility for soybean, sunflower and control diets did not differ from each other. Lower (P≤0.05) EE digestibility was observed for the control diet (73.67%). There were no differences (P≥0.05) in the ingestive behavior, however, the addition of cottonseed or sunflower negatively affected (P≤0.05) rumination efficiency of NDF. Sunflower should not be included in high concentrate diets for fattening lambs. RESUMO:Um experimento foi conduzido para comparar diferentes oleaginosas em substituição ao milho moído na dieta de cordeiros em engorda, avaliando o desempenho, a digestibilidade aparente da dieta, o comportamento ingestivo e as características de carcaça. Vinte e quatro cordeiros cruzados, com 3 meses de idade e peso corporal inicial de 25,97 ± 0,75 kg, foram mantidos em baias individuais. Eles receberam uma das seguintes dietas ou tratamentos: 'controle' (sem grãos de oleaginosas, 3,11% de Extrato Etéreo -EE), 'caroço de algodão' (6,14% EE), 'girassol' (6,33% EE) e 'soja' (6,30% EE). Todas as dietas continham 23,63% de feno de coast cross e 76,37% de concentrado. Após 84 dias de confinamento, os animais foram abatidos e as carcaças avaliadas. O consumo de matéria seca e ganho de peso diário dos animais alimentados com a dieta controle foi maior daqueles alimentados com girassol (P≤0,05). O peso corporal final e o peso da carcaça foram maiores (P≤0,05) para aqueles alimentados com a dieta controle (42,42 kg e 19,27 kg, respectivamente) que aqueles da dieta com girassol (34,85 kg e 16,05 kg, respectivamente). A digestibilidade da Fibra em Detergente Neutro (FDN) foi reduzida (P≤0,05) quando os animais receberam caroço de algodão (50,34%) comparado à soja (71,07%); para as dietas com girassol (67,07%) e controle (66,50%) não houve diferenças das demais. Menor (P≤0,05) digestibilidade do extrato etéreo foi observada para a dieta controle (73,67%). Não houve diferen...