Metabolizable energy value and effect on amino acid availability of medium-chain triglycerides in diets fed to chickens of different ages

Abstract

Three experiments were conducted to determine the energy value and digestibility of medium-chain triglycerides (MCT) in chickens. Triacylglycerol with capric acids (C10-TG) and triacylglycerol with capric and caprylic acids (C10C8-TG) were provided as the MCT sources. Sixty 3-day-old broiler chicks and 25 adult roosters were provided for the determination of nitrogen-corrected true metabolizable energy (TMEn) of MCT. Forty 3-week-old broiler chicks were provided for the determination of nitrogen-corrected apparent metabolizable energy (AMEn) of MCT. True amino acid availability of amino acids (TAAA) of a diet with MCT was determined using adult roosters. The TMEn of C10-TG (37.11–38.45 MJ kg −1) was not significantly different from that of yellow grease (YG, 39.29–40.54 MJ kg −1), a long-chain triglycerides (LCT), in 3-day-old chicks. In 3-week-old chickens, the AMEn of C10-TG (32.04 MJ kg −1) was comparable with that of YG (32.00 MJ kg −1). The TMEn (36.02–36.44 MJ kg −1) and AMEn (33.76 MJ kg −1) of C10C8-TG were higher to a certain extent than YG (AMEn: 32.00 MJ kg −1) and C10-TG (TMEn: 25.90–31.12 MJ kg −1; AMEn: 32.04 MJ kg −1). Digestibility of lipids in the basal diet (68.1%) and that of C10-TG (96.3–98.5%) was low in 3-day-old chicks as compared with those in roosters (78.8% and 100.0–107.9%). The digestibility of MCT (96.3–107.9%) was higher than YG (94.0–94.6%), irrespective of the age of chickens. TAAA was not influenced by the inclusion of MCT in the diet. It is suggested that the digestibility of C10-TG and C10C8-TG is higher than that of YG and the TMEn and AMEn values are comparable with that of YG. Therefore, MCT is a potential fat source for chickens, particularly for very young chicks.