Oilseeds in diets of fattening lambs

Abstract

An experiment was conducted to compare different oilseeds in substitution of ground corn in fattening lambs’ diet, evaluating ingestive behavior, apparent diet digestibility, performance and carcass characteristics. Twenty-four crossbred lambs, 3 month-old and initial body weight of 25.97 ± 0.75 kg, were kept in individual pens. They received one of the following diets: control (no oilseeds, 3.01% Ether Extract - EE), with cottonseed (6.86% EE), sunflower seed (6.93% EE), or soybean (4.75% EE). All diets contained 23.63% of coast cross hay and 76.37% of concentrate. After 84 days of feedlot, the animals were slaughtered and the carcasses evaluated. The dry matter intake and daily weight gain of animals fed with control diet was higher than with oilseeds (P≤0.05). Final body weight and carcass weight were higher (P≤0.05) with control (42.42 kg and 19.27 kg, respectively) than 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 (50.34%) than soybean (71.07%); sunflower (67.07%) and control (66.50%) diets did not differ among others. Lower (P≤0.05) ether extract digestibility was observed for the control diet (73.67%). There were no differences (P≥0.05) in the ingestive behavior, however, the inclusion of cottonseed or sunflower negatively affected (P≤0.05) the rumination efficiency of NDF. Cottonseed, sunflower and soybeans should not be included in high concentrate diets for fattening lambs.