Different sources of lipids for finishing feedlot lambs

Objective

The aim of this study was to evaluate the effects of different dietary lipid sources on feed performance in feedlot lambs.

Materials and Methods

A total of 30 noncastrated male lambs, Santa Inês (initial average weight of 29 ± 2 kg), were distributed in a randomized block design into 3 treatment groups (10 lambs per group): a diet with soybean oil, residual frying oil, or palm oil. The 3 experimental diets included lipids at 60 g∙kg⁻¹ of DM. The formulated diets, at a roughage-to-concentrate ratio of 40:60, consisted of elephant grass silage, milled corn, soybean bran, wheat bran, oil (soybean, residual frying oil, or palm), calcitic limestone, and urea. Fatty acid composition was determined. Sheep intake, digestibility, and performance were analyzed.

Results and Discussion

Dry matter and nutrient intakes, as well as average daily weight gain and G:F, were similar among the treatment groups. The difference was in the coefficient of digestibility of ether extract; in that regard, palm oil (852.2 g∙kg⁻¹) was superior to soybean oil and residual frying oil (77.96 and 81.40 g∙kg⁻¹, respectively). Among the oil tested, soybean oil had the highest levels of unsaturation (824.2 g∙kg⁻¹), followed by residual frying oil (779.6 g∙kg⁻¹), and palm oil (576.5 g∙kg⁻¹), which indicated that unsaturation levels do not alter nutrient intake when sheep diets contain adequate amounts of ether extract.

Implications and Applications

We conclude that lipid sources that differ in levels of unsaturation may be used without restriction in diets that contain normal amounts of ether extract (approximately 60 g∙kg⁻¹). Moreover, residual frying oil is an alternative lipid source that may be used in the diets of feedlot lambs.