Effects of different lipid sources on intake, digestibility and purine derivatives in hair lambs

Summary An experiment was conducted to evaluate the effects of different lipid sources on the nutrient intake, digestibility and purine derivative excretion of lambs. Thirty-five 60-day-old, male, non-castrated Santa Ines lambs with an initial average body weight (BW) of 13.00 ± 1.80 kg were used in a randomized complete block design with seven blocks and five treatments. The experimental treatments consisted of a control diet without supplemental lipids and four test diets with different lipid supplements, selected according to the degree of ruminal protection from hydrogenation: supplementation, being supplementation with whole cottonseed (WC), supplementation with cashew nut meal (CNM), supplementation with both cottonseed and cashew nut meal (WC-CNM) and supplementation with calcium salts of long-chain fatty acids (Ca-LCFA). The lambs were slaughtered after reaching 28 kg average BW for each treatment. The ether extract intake (EEI) was higher (p   0.05) by the different lipid sources. A lower purine derivative (PD) excretion and thus lower microbial protein supply (MPS) was observed for animals supplemented with Ca-LCFA (p < 0.01) compared to the WC-CNM and control diets. In conclusion, WC, CNM and WC-CNM supplementation did not have negative effects on MPS, although negative effects have been observed on nutrient digestibility.