Interrelationship between late gestational ewe factor and early life lamb factors in semi-arid tropical region.

The limitation in feed availability in the semi-arid region during the lean period can result in a variation of the body condition, body weight of pregnant ewe which in turn may affect the lamb birth weight, colostrum immunoglobulin, growth hormone (GH), and insulin-like growth factor-1 (IGF-1). Therefore, the present study was initiated to assess the interrelationship between late gestational ewe factor and early life lamb factors in the semi-arid tropical region. For this purpose, 83 Malpura and 45 Avikaline pregnant ewes were selected and their body condition score (BCS) at late gestation, body weight at lambing, and birth weight of lambs was recorded. The BCS of ewes in late gestation had significant (P < 0.001) positive correlation (r2 = 0.465) with the birth weight of lambs. The body weight at lambing was significantly (P < 0.05) higher in single-lamber ewes as compared to twin-bearing ewes. The plasma IGF-1 of lamb increased significantly (P < 0.05) with the increase of BCS of ewe at the late gestation as well as body weight after lambing. The colostrum of twin-lamb producing ewes had higher (P < 0.05) IgG content than single-lamb producing ewes. The concentration of IGF-1 was significantly (P < 0.05) higher in single-born lamb as compared to twin-born lamb. Based on the results of the present study, it is to conclude that higher BCS at late gestation and higher body weight of ewes at lambing is desirable for producing lambs with a higher birth weight having higher growth potential as well as chances of survival.