title: Pre-weaning growth performance of crossbred lambs (Dorper × indigenous sheep breeds) under semi-intensive management in eastern Ethiopia.
abstract: A study was conducted to assess the effect of genetic and non-genetic factors (litter size, sex of lamb, and parity of dam) on pre-weaning growth performance of crossbred lambs (75% Dorper (DR) 25% indigenous lambs; and 50% Dorper 50% indigenous lambs) under semi-intensive husbandry practices in eastern Ethiopia. Data from a total of 275 Dorper sire breed × indigenous (Blackhead Ogaden [BHO] and Hararghe Highland [HH]) crossbred lambs with different genetic group of the parental breeds were collected for three consecutive years (2009 to 2011). Pre-weaning growth performance attributes of crossbred lambs studied were birth weight, weaning weight, and pre-weaning average daily gain. Data were analyzed using the GLM procedure of SAS (2003). Breed group and non-genetic factors significantly affected pre-weaning growth performance. Lambs with 75% Dorper and 25% indigenous had higher (P < 0.01) birth weight than 50% DR and 50% HH but similar to 50% DR and 50% BHO. Weaning weight and pre-weaning live weight gain were higher (P < 0.01) for ¾DR¼BHO and ¾DR¼HH than 50% Dorper inheritance. Single-born lambs had higher weight at birth, weaning weight, and pre-weaning average daily gain as compared to twins. Sex comparison is significant (P < 0.05) and male lambs recorded highest pre-weaning growth performance compared to female counterparts. Parity, season, and lambing year significantly (P < 0.01) influenced the pre-weaning growth of crossbred lambs. Therefore, it could be concluded that 50-75% Dorper inheritance improved pre-weaning growth performance of indigenous breeds of Hararghe Highland and Blackhead Ogaden sheep. The result also suggested culling of ewes older than fourth parity to improve the pre-weaning growth performance of lambs.
authors.affiliation: College of Agriculture and Environmental Sciences, School of Animal and Range Sciences, Haramaya University, P.O. Box 236, Dire Dawa, Ethiopia, ttmamy06@gmail.com.
authors.forename: Tsegay
authors.initials: T
authors.lastname: Teklebrhan
authors.forename: Mengistu
authors.initials: M
authors.lastname: Urge
authors.forename: Yoseph
authors.initials: Y
authors.lastname: Mekasha
authors.forename: Merga
authors.initials: M
authors.lastname: Baissa
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D000833:Animals, Suckling; D005002:Ethiopia; D005260:Female; D008297:Male; D012756:Sheep / Q000235:genetics / Q000254:growth & development*; D014886:Weaning; D015430:Weight Gain / Q000235:genetics