Effect of different dietary energy levels on physio-biochemical, endocrine changes and mRNA expression profile of leptin in goat (Capra hircus)

Abstract

This study aims to assess the effect of different energy levels of restriction on physiological and genetic level adaptability. Eighteen adult nonpregnant does (average BW 33.56kg) were used in the present study. The ewes were divided into three groups, viz., GI (n=6; control), GII (n=6; 30% feed intake of control), GIII (n=6; 40% feed intake of control). The study was conducted for 40 days covering a period of two estrous cycles. Blood samples were collected every ten days interval. The parameters studied were allometric parameters (viz., body weight, and body condition) scoring and physiological responses (viz., respiration rate, pulse rate, and rectal temperature) biochemical parameters (glucose, albumin, creatinine, cholesterol), hormones (T3, T4, cortisol, leptin) and mRNA expression profile of leptin in peripheral blood mononuclear cells (PBMC). The nutritional stress significantly (P<0.05) affected most of the parameters. There was a significant (P<0.05) reduction in Body weight, Body condition score and. The physiological responses were significantly (P<0.05) affected. Among the biochemical parameters mean serum glucose first increased significantly (P<0.05) and then stabilized in GII whereas as there was no change in serum glucose levels in GIII. Serum albumin significantly (P<0.05) affected in late stages of study. There was no significant (P<0.05) changes in serum creatinine. Among hormonal parameters there was significant decrease in T3 in both the groups; T4 increased significantly in GII on 10th day and then stabilized whereas no changes was observed in GIII. Cortisol levels increased significantly (P<0.05) in both GII and GIII. There was a significant (P<0.05) reduction in serum leptin levels in GII but in GIII significant reduction was observed only 10th and 30th day of study. The mRNA expression was significantly (P<0.05) upregulated in GII on 30th day followed by a significant downregulation whereas in GIII significant (P<0.05) downregulation was only seen on 30th and 40th days. It can be concluded from our study that animals can maintain near physiological homeostasis even at 40% energy intake levels. The animals have innate physiological ability to survive periods of nutritional stress by adjusting leptin levels which are required for maintaining the physiological normalcy.