Effects of metabolizable energy intake on post weaning lamb growth performance, carcass tissue composition and internal fat depend on animal characteristics: A meta-analysis.
animals
metabolisable energy intake (MEI)
low medium and high energy density diets
growth performance, carcass tissue composition, internal fat
Abstract
This study aimed to establish the quantitative relationship between metabolisable energy intake (MEI) and growth performance, carcass tissue composition and internal fat, taking into consideration animal precocity, maturity and tail nature. Data from 67 publications were used in the meta-analysis. Diets were characterized and three classes were identified (low medium and high energy density diets). Breeds were characterized according to tail nature, precocity and maturity stage. Average daily gain (ADG) responded to MEI in all animals weighing less than 60% of their adult weight regardless their precocity or their tail nature. At the same level of MEI, the higher the diet energy density, the higher the ADG. In animals weighing less than 42% of adult weight and receiving a high starch diet, carcass muscle and internal fat responded to MEI. Whereas, for animals that weighed between 43% and 75% of adult weight, increases in MEI influenced carcass adipose tissue.