229
Performance by Dorper-Katahdin Crossbred Lambs Weaned Using Two Different Weaning Methods
Weaning can be stressful on young animals and commonly results in decreased performance. However, alternative weaning methods have been advocated as management practices to reduce stress and increase performance, particularly in cattle; although, little research has been published on their effectiveness in hair sheep. The objective of this study was to evaluate the effects of traditional compared with fenceline weaning methods on the performance and behavior of Dorper-Katahdin crossbred lambs. Over 2 consecutive y, Dorper-Katahdin crossbred lambs (n = 168; 74 ± 4.4 d of age) were stratified within litter, weight, BCS, and sex and were allocated randomly to 1 of 12 groups, 7 d prior to weaning. Groups were then assigned randomly to treatments consisting of 1) fenceline weaning (6 replications) or 2) traditional weaning (6 replications). Fenceline weaned lambs were placed in 37.2 m2 drylots adjacent to their dams while traditional weaned lambs were placed in the same size drylots away from their dams. All groups had ad libitum access to endophyte-infected tall fescue [Lolium arundinaceum (Schreb.) Darbysh] hay, water, mineral, and were offered a grain supplement at 1% of BW (as-fed). Weaning weight, 14-d post-weaning weight, ADG, gain (14-d), total ADG, and total gain (43-d) did not differ (P ≥ 0.70) across treatments. Also, the percentage of lambs walking rapidly, running, standing, and lying down did not differ (P ≥ 0.28) across treatments. However, a weaning method × time interaction (P ≤ 0.05) was observed for percentage of lambs vocalizing, with more lambs vocalizing in the fenceline treatment at 12 h. A time effect (P ≤ 0.05) was detected for percentage of lambs running, standing, and lying down with the highest percentage of lambs running at 12 h compared with 24, 48, or 72 h, a lower percentage of lambs standing at 24 h compared with 12, 48, or 72 h and a lower percentage of lambs lying down at 12 h compared with 24, 48, or 72 h after weaning. Although well established using cattle, fenceline weaning of lambs may not improve performance or behavior.
Keywords: Fenceline, Lambs, Weaning