-
Views
-
Cite
Cite
A. R. Weaver, D. L. Wright, D. R. Notter, A. M. Zajac, S. A. Bowdridge, S. P. Greiner, 104 Evaluation of Pre-Weaning and Grazing Performance of Terminal Sire Breeds for Hair Sheep Production Systems, Journal of Animal Science, Volume 95, Issue suppl_1, December 2016, Pages 51–52, https://doi.org/10.2527/ssasas2017.0104
Close - Share Icon Share
Abstract
Profitability of hair sheep enterprises may be enhanced with the use of terminal sires which improve growth performance while maintaining parasite tolerance in crossbred progeny. Katahdin (KT, n = 2), Suffolk (SU, n = 2), and Texel (TX, n = 2) rams were randomly mated to KT ewes (n = 82) at the Virginia Tech Southwest Agricultural Research and Extension Center. Post– lambing until weaning (80-d age), ewes and lambs were managed on fescue pasture. At weaning, lambs were moved to an ungrazed fescue pasture and provided a concentrate pellet (13% CP, 75% TDN) at 2.0% BW as fed daily for an 84-d summer grazing trial. During this summer grazing trial, BW, strongylid egg count (FEC), FAMACHA scores and packed cell volume (PCV) were collected every 14-d. FAMACHA score ≥ 3 was utilized as the basis for deworming. All statistical analyses were conducted using SAS (SAS Institute Inc., Cary, NC) PROC mixed for repeated measures analysis and PROC GLM. Tukey's test was used for comparative means analysis. Adjusted (birth type, dam age, sex) BW at birth was greater for SU– sired lambs (5.4 kg) than KT– sired (4.8 kg, P < 0.01) and TX– sired (5.0 kg, P < 0.05). There were no differences in adjusted (dam age) number of lambs born or weaned per ewe. Adjusted (birth/rear type, dam/lamb age, sex) BW at weaning was lightest for KT– sired lambs (20.3 kg, n = 71) compared to both SU–sired (22.7 kg, P < 0.01, n = 35) and TX–sired (21.9 kg, P < 0.05, n = 43). BW, ADG, FEC, FAMACHA and PCV varied over time (P < 0.01) during the summer grazing trial with no sire breed effects for ADG, FEC or PCV. BW and FAMACHA tended to be affected by sire breed. SU– sired lambs tended to require fewer days until first deworming than TX–sired lambs (28 vs. 50 d, P = 0.051). At the time of deworming, SU– sired had the lowest FEC (1,726 egg/g) compared to both KT– sired (3,578 eggs/g, P < 0.05) and TX– sired lambs (3,690 eggs/g, P < 0.05). These results indicate the potential of TX–sired lambs to increase preweaning BW while maintaining parasite resistance similar to the KT–sired lambs through a summer grazing trial.
