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Production and heterosis by the Merino, Polwarth and their reciprocal crosses

Citation

Butler, LG and Horton, BJ and Williams, PM and Banks, RG, Production and heterosis by the Merino, Polwarth and their reciprocal crosses, Australian Journal of Experimental Agriculture, 33 pp. 397-402. ISSN 0816-1089 (1993) [Refereed Article]

DOI: doi:10.1071/EA9930397

Abstract

Tasmanian Merinos and Polwarths were mated in each of 2 years to produce 2 drops of Merino, Polwarth, and F1 reciprocal cross progeny. Polwarths had weaning weights similar to Merinos but were 14% heavier as hoggets. Polwarths grew a similar amount of wool of 11% greater (P < 0.001) fibre diameter; however, wool production was 9% less efficient based on metabolic weight. Polwarths displayed an advantage in resistance to footrot. There was a marked Polwarth maternal effect of about 16% on weaning weight but no elfect on hogget weight. The Polwarth maternal effect on fleece weight and efficiency was 9% (P < 0.001). In a comparison with a single-born male, ewes weighed 5% less at weaning and 7% less at hogget shearing and produced about 6% less wool (P < 0.001), although of comparable fibre diameter. Twins weighed 17% less at weaning, but only 3% less at hogget shearing (P < 0.001). They grew about 5% less wool, which was of 2% greater fibre diameter (P < 0.001) and 5% higher wool score, but efficiency was 2.5% lower. Production was generally lower (except for yield and wool score) in the 1988 drop than the 1987 drop by 3-10%. Differences in productivity between ram sources were of only slightly lesser magnitude than differences between breeds. The number of feet affected by footrot was reduced by 17% in the 1988 drop. Severe footrot affecting more than 1 foot reduced liveweight but did not significantly reduce fleece weight. There appeared to be some heterosis for weaning weight (10%) and hogget weight (6%), but little heterosis in wool growth (2-3%) or efficiency (-2%). © 1993 CSIRO.

Item Details

Item Type:Refereed Article
Research Division:Agricultural and Veterinary Sciences
Research Group:Animal Production
Research Field:Animal Protection (Pests and Pathogens)
Objective Division:Animal Production and Animal Primary Products
Objective Group:Livestock Raising
Objective Field:Sheep - Wool
UTAS Author:Horton, BJ (Dr Brian Horton)
ID Code:69880
Year Published:1993
Web of Science® Times Cited:3
Deposited By:Agricultural Science
Deposited On:2011-05-23
Last Modified:2011-05-23
Downloads:0

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