THE EFFECT OF THE LENGTH AND SEVERITY OF FEED RESTRICTION ON WEIGHT, CARCASS MEASUREMENTS AND BODY-COMPOSITION OF GOATS

Two experiments were done in Mexico (1992-93) to determine the respons e of goats to different periods of feed restriction on liveweight, org an weights and tissue composition. In each, the weight, body condition and daily dry matter intake (DMI) of two groups of 12 female, adult, non-lactating, non-pregnant, Nubian crossbred goats were recorded for 7 weeks (stabilization period; SP), to allow the animals to reach and maintain their liveweight and body condition. At the end of the SP the animals in Expt 1 (RP1) were feed restricted for 18 weeks and for 36 weeks in Expt 2 (RP2). Animals were divided into three groups receivin g either 100 (FL1), 80 (FL2) or 60% (FL3) of the levels of DMI previou sly observed. At the end of each experimental period all animals were slaughtered, carcass weights were recorded and viscerae were weighed. A sample of the soft tissues was chemically analysed. There were no si gnificant changes in body condition in either experiment (P > 0.05). N one of the feeding levels had an effect on carcass weight or the chemi cal composition of soft tissues (P > 0.05). Liver weights (as a propor tion of slaughter weight) were significantly different among goats fed at different feeding levels in both experiments. The results of this study show the adaptation capacity of adult goats to medium and long t erm malnutrition, and the importance of the liver as a source for the generation of energy and for sustaining protein turnover. This could b e especially important for goats grazing in arid and semi-arid zones w here dry periods can last for months and feed availability is therefor e sometimes limited.