Development and characteristics of adipose deposits in male kids during growth from birth to weaning

Abstract

AbstractThe variation of weight, degree of lipid infiltration and lipoprotein lipase (LPL) activity were studied in seven adipose tissues of Alpine and Saanen kids during five trials where animals were fed with milk replacer, were either weaned or unweaned, were either unfasted or fasted during 24 h and were slaughtered at 8, 10, 12, 14, 18 or 20 kg live weight.At every live weight, kid carcasses were characterized by a relatively-high proportion of visceral adipose tissues: omental, mesenteric, perirenal and pericardic tissues (about half of total adipose tissues) and by a low deposition of external fat and a low lipogenic activity in the subcutaneous tissues. The intermuscular adipose tissue of the leg was the most rapidly developing tissue (coefficient of allometry 2·26) followed by omental (2·13), mesenteric (1·55), perirenal (1·48) and pericardic (1·38) tissues.The perirenal, omental and inguinal tissues had the highest lipid content and LPL activity, and the sternal, caudal and mesenteric the lowest. There was a positive intertissue correlation (+0·80) between the lipid concentration and the LPL activity of adipose tissues, However, the lipid concentration of the omental tissue increased while its LPL activity per g tissue decreased with increasing live weight of the animal.After a 24-h fast, a tendency to a proportional decrease in the weight of all adipose tissues by 0·20 to 0·35 and in the LPL activity by 0·36 to 0·88 was observed; the weight and LPL activity losses of the perirenal tissue were the greater.Fourteen days after weaning the weight losses of adipose tissues remained high but the LPL activities increased again, showing an early recovery of lipogenic activity after weaning. However, they did not reach the values recorded during the pre-weaning period.In kids, each adipose tissue had its own characteristics and played a specific role in lipid metabolism both during lipogenesis and lipolysis.