Effect of weaning age on hair sheep lamb and ewe production traits in an accelerated lambing system in the tropics1

Abstract

This study was designed to evaluate the impact of weaning age on lamb and ewe productivity in an accelerated lambing system. St. Croix White (STX) and Dorper × St. Croix White (DRPX) lambs were assigned at birth based on breed, gender, and litter size to be weaned at 63 (Early-1; 106 lambs and 68 ewes) or 90 d of age (Late-1; 99 lambs and 60 ewes) in Exp.1 or at 63 (Early-2; 77 lambs and 57 ewes) or 120 d of age (Late-2; 75 lambs and 56 ewes) in Exp. 2. After weaning, lambs were weighed weekly and fed a concentrate ration (2% BW·lamb·d) while grazing guinea grass pastures. In Exp. 1, weaning weight was greater ( < 0.0001) for Late-1 lambs than for Early-1 lambs (14.6 ± 0.3 vs. 11.0 ± 0.3 kg, respectively) and greater ( < 0.008) for DRPX lambs than for STX lambs (13.9 ± 0.4 vs. 11.5 ± 0.4 kg, respectively). Litter weaning weight was greater ( < 0.004) for Late-1 ewes than for Early-1 ewes (20.9 ± 0.8 vs. 17.4 ± 0.8 kg, respectively). Ewe efficiency ([ewe BW at weaning/litter weaning weight] × 100) was greater ( < 0.004) for Late-1 ewes than for Early-1 ewes (50.7 ± 1.9 vs. 42.3 ± 1.8%, respectively). Lamb weight gain between 63 and 90 d of age was lower ( < 0.03) for Early-1 lambs than for Late-1 lambs (2.7 ± 0.2 vs. 3.6 ± 0.3 kg, respectively). In Exp. 2, weaning weight was greater ( < 0.0001) for Late-2 lambs than for Early-2 lambs (18.7 ± 0.4 vs. 11.8 ± 0.4 kg, respectively) and greater ( < 0.008) for DRPX lambs than for STX lambs (16.9 ± 0.5 vs. 13.3 ± 0.5 kg, respectively). Litter weaning weight was greater ( < 0.0001) in Late-2 ewes than in Early-2 ewes (27.2 ± 1.0 vs. 17.5 ± 0.9 kg, respectively). Ewe efficiency was greater ( < 0.0001) for Late-2 ewes than for Early-2 ewes (68.1 ± 2.2 vs. 41.9 ± 2.0%, respectively). Lamb weight gain between 63 and 120 d of age was not different ( > 0.06) between Early-2 and Late-2 lambs (5.1 ± 0.2 vs. 5.6 ± 0.3 kg, respectively). In Exp. 1 and 2, ewe BW at breeding and lambing and weaning and lambing rate were not different among weaning ages of lambs ( > 0.17). The Early-1 ewes exhibited estrus earlier than Late-1 ewes (10.9 ± 0.9 vs. 13.9 ± 1.0 d, respectively) but there was no difference ( > 0.63) between Early-2 and Late-2 ewes. Weaning hair lambs at 90 or 120 d of age can be done in an accelerated lambing system with no detrimental effect on lamb or ewe productivity. Late weaning resulted in a decreased number of days that lambs received high-cost, imported feed without a reduction in growth, resulting in savings of US$6 to $15 per lamb.

Ewe and lamb pre-weaning performance of Pelibuey and Katahdin hair sheep breeds under humid tropical conditions

“…The LWW of 15.5 kg and 16.1 kg for Pelibuey and Katahdin ewes estimated in this study were lower than the values for these breeds (21.2 kg and 22.4 kg, respectively) reported by Nasrat et al (2016). The values of EE for both breeds considered in this study were lower than those reported by Godfrey and Weis (2016) using St. Croix White and Dorper  St. Croix, meaning that Pelibuey and Katahdin breeds had less overall productivity than the crossbred ewes used in the Godfrey and Weis (2016) study. Similarly, the values of EE are lower than values reported by Godfrey et al (1997) who reported EE ranging from 42.3 to 47.3 for Barbados Blackbelly and St. Croix White hair ewes; furthermore, consistently with the present results, the authors found that the twin-bearing ewes were more efficient to than those single-bearing ewes (37.2 vs 49.1).…”

“…Milk production and composition have been evaluated in Pelibuey ewes (Castellanos and Valencia 1982;Espinoza-Hern andez et al 2013) and crossbred Pelibuey  Katahdin ewes (Peniche et al 2015). Other few studies have evaluated weights of lambs at birth and weaning of purebred and crossbred hair sheep (Godfrey et al 1997;Mac ıas-Cruz et al 2012;Nasrat et al 2016;Godfrey and Weis 2016). Litter size at birth and weaning and lamb survival at day 30 and weaning were evaluated in the study of Mac ıas-Cruz et al (2012).…”

What Do We Know and Need to Know About Weaning in Sheep? An Overview of Weaning Practises, Stress and Welfare

“…The response follows a similar pattern in other physiological traits; e.g., concentrations of lactate dehydrogenase and creatine kinase are higher in lambs weaned at 45 than at 75 d of age (Çakmakçi et al, 2021), and total protein concentration is lower in younger than older weaned lambs (Çakmakçi et al, 2021). The earlier the lambs are weaned, the lower their subsequent weight gains are, even when grazing pasture and/or receiving food supplementation (Cañeque et al, 2001;Godfrey and Weis, 2016). This effect might be due to a lack of adaptation to solid food as a unique food resource.…”

Effects of milking system in suckling period on growth, reproduction traits, and milk yield of East Friesian-cross dairy sheep

“…It was reported that number of corpora lutea present and pregnancy rates of the mothers of the early (69 days) and late (91) lambs weaned did not significantly affect Romney sheep (deNicolo et al, 2006). Also, the effect of time of weaning on subsequent reproductive performance of ewes was similar in Barbados Blackbelly sheep (Knights et al, 2012) and St. Croix White and Dorper sheep (Godfrey and Weis, 2016). With the available data set and findings of the effect of milking during suckling in Tahirova ewe, it is not possible to give any conclusions on the reproductive performance of the ewes in the present study.…”

“…It has been determined that suckling or partly milking programs significantly affect the growth of lambs and the milk yield characteristics of ewes (Knight et al, 1993;McKusick et al, 2001;Margetín et al, 2020). While there are several studies on the effects of the practices in suckling period on the next reproductive performance of ewes (deNicolo et al, 2006;Godfrey and Weis, 2016;Murphy et al, 2017), studies on the breeding performance of the female lambs are scarce (Gaskins et al, 2005).…”