Intake, digestibility, serum metabolites, and growth performance of male feedlot lambs fed different fat sources

Abstract

The experiment was conducted to evaluate the inclusion of different sources of fat on the intake and digestibility of nutrients, serum metabolites, and growth performance of feedlot lambs. Forty male Dorper × Santa Inês lambs (averaging 22.27 ± 2.79 kg of body weight; mean ± standard deviation) with approximately 4 months were distributed in a completely randomized design. Five experimental diets were tested: no added fat (NAF), whole soybeans (WSB), calcium salts of fatty acids (CSFA), soybean oil (SO), and full fat corn germ (CG). Nutrient intake was affected by the inclusion of different fat sources in diets (P < 0.05) except for the neutral detergent fiber (aNDFomp). The CSFA diet showed the highest nutrient apparent digestibility (P < 0.05), except for the digestibility of aNDFomp and non-fibrous carbohydrates. Nitrogen retention was higher (P = 0.003) in animals fed the CSFA diet. Albumin (P = 0.038), albumin:globulin ratio (P = 0.042), glucose (P < 0.001), and cholesterol (P = 0.032) were affected by the inclusion of different fat sources in feedlot lamb diets. Lambs fed NAF and CSFA diet showed the highest average daily gain (P = 0.001) and final body weight (P = 0.036). The use of 3.5 % calcium salts of fatty acids (protected fats); improves the diet digestibility and promoted the highest growth performance parameters in feedlot lambs.