Risk Factors Associated with Passive Immunity, Health, Birth Weight and Growth Performance in Lambs: II. Effects of Passive Immunity and Some Risk Factors on Growth Performance During the First 12 Weeks of Life

Abstract

Summary The primary objective of this study was to evaluate the relationship between passive immunity and growth performance in lambs in neonatal and post-neonatal periods. The study also evaluated the effect of gender, type of birth, birth weight and health of lambs, lambing season and dam’s age on growth performance. This study included two crossbred Akkaraman flocks (n=301) in Kars, Turkey. The results disclosed that serum IgG concentration determined at 24th of birth (SIgG-24) was significantly associated with growth performance in both periods (P<0.001) but this relationship was poor (R 2 =0.148 to 0.198). Neonatal growth performance was influenced only by birth weight, health status, SIgG-24 and type of birth (P<0.001, R 2 =0.527 to 0.721) on multiple stepwise regression analyses. The study also disclosed that post-neonatal growth performance was affected by all variables (P<0.001, R 2 =0.471 to 0.472). This study suggested that passive transfer cause a significant amount of variation in growth performance for lambs from birth to 12 weeks of life, a conclusion that has not previously been identified. It also disclosed positive association among growth performance, birth weight, type of birth, gender, health status of lambs, dam’s age and lambing season. The growth performance was rendered by dam’s age (≤2 years old), twin lambs, female lambs, winter lambing, illness, and birth weight of ≤3 kg. These factors should be taken into consideration and dealt with in order to increase growth performance so that which farm productivity and profitability is maintained.