Relationship of ewe productivity with body weight and age of Horro ewes
1996
Solomon Abegaz (Bako Research Center (Ethiopia)) | Twaithes, C.J. | Goshu Mekonen
A total of 1822 lambing records of Horro ewes collected over a 15 year period (1978/79-1992/93) was examined to estimate the relationship of ewe productivity as measured by litter size (LS), number of lambs weaned/ewe lambing (NLW), kg of lamb weaned per ewe lambing (KGWL), g of lamb weaned per kg body weight of ewe lambing (GWKG), and g of lamb weaned per metabolic body weight (kg 0.73) of ewe lambing (GWKGM), with body weight and age of ewe at mating. Age of ewe had shown significant linear (p less than 0.01) relationship with LS and curvilinear (p less than 0.05) relationship with KGWL, GWKG, and GWKGM. Peak values for KGWL, GWKG, and GWKGM were at 2-3 years of age with a slight decline to 5-6 years of age and drastic drop thereafter. The relationship of ewe weight was significant (p less than 0.001-0.01) and linear with all traits except GWKG (p greater than 0.1). But there existed a slight non significant decline in GWKG and GWKGM in ewes weighing greater than 36 kg. At current feeding conditions excessively high weight are less of a problem than lower weights. The study indicates that ewes should not be kept to age exceeding 6 years and ewe productivity is highest in ewes with body weights of greater than 33 kg. Excessively higher weights should be avoided
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