Administration of Branched-Chain Amino Acids in the Pre- or Post-Hatch Period Improves the Fiber Characteristics of Pectoralis major Muscle in Turkey Poults Subjected to Early or Delayed Feeding

Poultry meat quality is controlled by muscle fiber properties associated with body weight gain in the immediate pre- or post-hatch period. This study aimed to determine the effect of administration of branched-chain amino acids blend (BCAAb, 3 L-leucine:1 L-isoleucine:2 L-valine) in the pre- or post-hatch period on the growth performance and fiber characteristics of the Pectoralis major (PM) muscle in turkey poults subjected to early or delayed feeding. Newly hatched poults from eggs injected in ovo with BCAAb or received no injection were used in a 21-d study. Poults (n=192) produced without injection of BCAAb received a starter diet supplemented (BCAA) or not (C) with the BCAAb (2 g/kg) immediately or with a delay of 48 h (48BCAA and 48C) after hatching. Poults (n=36) produced with (IOBCAA) in ovo injection of BCAAb (2 mg /ml) received the diet and water immediately. The BCAA and IOBCAA poults had higher body weight than those of the C, 48C, and 48BCAA birds. The body weight of the C poults was higher than those of the 48C and 48BCAA birds. The BCAA poults had higher PM muscle weight than those of the C and 48C poults, while that of the IOBCAA poults was higher than that of the 48C poults. The IOBCAA treatment increased the protein content of the PM muscle meat, compared with the C and 48C treatments. The 48C treatment increased the type IIB fiber area and the type I and type IIA fiber percentages but decreased the type IIB fiber, compared with other treatments. The numbers of type IIB and total fibers in the IOBCAA poults were higher than those of the 48C birds. In conclusion, administering BCAAb in ovo or in a starter diet enhanced early growth performance and improved the fiber characteristics of the PM muscle in turkey poults.