Effect of passive transfer status on preweaning growth performance in dairy goat kids

Objective-To evaluate the effect of passive transfer status (determined from measurements of serum IgG concentration at 24 hours after parturition [slgG-24]) on preweaning growth performance in dairy goat kids. Design-Prospective observational study. Animals-20 healthy nursing dairy doe kids in a natural nonintensive breeding environment. Procedures-For each kid, slgG-24 was measured. Body weight was measured at birth and at the time of weaning 30 days (ie, 29 to 31 days) after birth; average daily gain from birth to day 30 and weight at day 30 were used as measures of preweaning growth performance. Regression analysis was used to evaluate associations between slgG-24 and measures of preweaning growth performance. Results-Mean ±SD slgG-24 was 31.7 ±10.3 mg/mL Mean body weights at birth and weaning were 4.105 ±0.981 kg (9.031 ±2.158 Ib) and 9.310 ±2.554 kg (20.482 ±5.619 Ib), respectively; average daily gain was 0.174 ±0.072 kg/d (0.383 ±0.158 Ib/d). No significant association was detected between slgG-24 and birth weight. However, slgG-24 was significantly associated with average daily gain (R2 = 0.48) and weight at day 30 (R2 = 0.56). Each increase in slgG-24 of 1 mg/mL was associated with an increase in average daily gain of 0.005 kg/d (0.011 Ib/d) and an increase in weight at day 30 of 0.185 kg (0.407 Ib). Conclusions and Clinical Relevance-Results indicated that passive transfer status (determined as slgG-24) was a significant source of variation in preweaning growth performance in dairy doe kids reared in this nonintensive breeding environment.