Effects of weaning lambs in two stages or by abrupt separation on their behavior and growth rate

¹ Department of Animal Breeding and Genetics, Georg August University, 37075 Göttingen, Germany

^* To whom correspondence should be addressed. E-mail: Mgauly{at}gwdg.de.

	Abstract

A study was conducted to evaluate effects of age at weaning in combination with different procedures on 2 breeds of lambs (Merinoland, Rhoenschaf). Lambs were either weaned at 8 or 16 wk of age in 2 stages or with the traditional method of weaning by abrupt separation. In the 2-stage treatment, lambs were prevented from nursing their dam for 1 wk (stage 1) before their separation (stage 2). Control animals were nursed by their dams until they were separated. Lamb weights and behavior (vocalization, agitation) were recorded before and after separation. Following separation, lambs weaned at 8 wk of age had greater (P = 0.004) ADG compared with lambs weaned at 16 wk of age. Control lambs had greater (P < 0.001) agitation scores (1 = no agitation: 'normal' behavior, i.e. feeding, resting, lying, standing or play behavior, 3 = high agitation: continuously moving, restlessness, vocalization) irrespective of weaning age and breed. On the day of separation, 2-stage lambs had scores between 1.17 and 1.35, whereas control lambs were scored between 1.70 and 1.79. Following separation, lambs weaned in 2 stages vocalized up to 98.2 % less (P = 0.001) than control animals. Furthermore bleats were greater for Rhoenschaf lambs and at a weaning age of 8 wk (P < 0.05). Differences between treatments were greatest on the day of separation. Vocalization decreased within the first 3 d of weaning continuously to zero. Lambs weaned in 2 stages were less distressed than lambs weaned by the traditional method of abrupt separation based on behavioral data, but ADG until 12 and 16 wk of age did not differ (P > 0.05) for either treatment in this study.

Key Words: behavior, lambs, productivity, sheep, weaning