Effect of a long term feeding restriction on the subsequent body weight, condition score, and tissue composition of mature goats

摘要

To observe the response of mature goats to long-term feeding restriction and the effect on their body weight, condition and composition, an experiment was conducted with 21 adult, female, non-gestating, non-lactating Nubian goats. For a 9-wk stabilization period, the body weight and body condition score of each animal were measured weekly, along with their voluntary feed intakes. After the stabilization period, goats were randomly assigned to three groups, being offered 100%, 80%, and 60% of the feedintake observed during this period, for a 36-wk restriction period. Chemical analyses were performed on samples of carcass components, heart, kidneys, and intestines. Body weight and body condition score decreased with reduced feeding levels. Moreover,the proportion of bone increased, and that of the carcass soft tissues, kidney fat, and liver decreased, as did the dry matter contents of heart, kidneys, and rumen contents; kidney protein, heart, and ether extracts of the carcass soft tissue; heart andliver DNA; and the RNA-.DNA and protein:DNA ratios in hepatic tissue. The C16:l fatty acid content of the kidney fat of goats on treatment FL60 was increased; in restricted animals, C16:l, C18:l, and unsaturated fatty acids in the subcutaneous fat wereall increased. These results suggest that the adaptation capability of adult goats to long-term undernutrition through the utilization of metabolic fuel from adipose tissue, skeletal muscle, liver, heart, and kidneys is an important survival characteristic for free-ranging animals kept in areas where drought conditions can last for several months, with consequent limitations on feed availability.