Relationship Between Growth Performance, Passive Immunity and Health In Preweaned Lambs

Abstract

This study was designed to investigate associations between transfer of passive immunity, selected illness-es (diarrhoea, pneumonia, and fatigue anorexia syndrome-FAS) and growth performance [body weight (BW) and aver-age daily gain (ADG)] in preweaned lambs. A total of 347 lambs were blood sampled at 24±1 h of age after birth and the serum IgG concentration for each lamb was measured after colostrum intake using a commercial ELISA kit. Lambs were weighed on a scale immediately after birth (before colostrum intake) and reweighed on day 28 (end of neonatal period) and day 84 (age of weaning). Lambs ADG was calculated from 0 to 28 d of life, from 29 to 84d of life, and from 0 to 84 d of life. Growth performance (BW and ADG) of lambs with diarrhoea and FAS in the neonatal period and with pneumonia in the postneonatal period was significantly lower than that of healthy lambs of the same period (P<0.05). BW of lambs with serum IgG concentration at 24th hour after the birth (SIgGC-24)<600 mg/dL and <1000 mg/ml was significantly lower on days 28 and 84 than that of lambs with SIgGC-24 >600 mg/dL and >1000 mg/ml (P<0.001). Simi-larly, the ADG of lambs with SIgGC-24 <600 mg/dL and <1000 mg/ml was significantly lower on days from 0-28, 29-84 and 0-84 of age than those of lambs with SIgGC-24 >600 mg/dL and >1000 mg/ml (P<0.001). In conclusion, our find-ings show that low serum IgG concentration in lambs, as well as the presence of pneumonia, diarrhea and FAS, reduc-es growth performance in pre-weaning lambs.