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Evaluation of Crossbreeding Effects for Wool Traits in Sheep
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 Title & Authors
Evaluation of Crossbreeding Effects for Wool Traits in Sheep
Malik, B.S.; Singh, R.P.;
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Crossbreeding effects for wool quality traits viz. greasy fleece weight (kg), staple length (cm), average fibre diameter () and medulation percentage were estimated using the Dickerson's and Kinghorn's models. The data analyzed involved 15 genetic groups including Nali purebred, 's of two and three breeds, 's and reciprocal crossbred obtained from the crossing of Nali (N), Merino (M) and Corriedale (C) breeds during 1980-96. Nali and Corriedale breeds had non-significant negative additive genetic effects (Dickerson's model) on greasy fleece weight, while effects of Corriedale were negative for staple length only from both models. In general additive genetic effects of all three breeds were non-significant for all the wool traits except medulation percentage. Non significant heterotic and recombination effects (epistatic loss) were estimated from both models. However, the estimates of crossbreeding effects varied between the models both in magnitude as well as in direction barring few exceptions. Undesirable positive heterosis was found on medulation percentage for all types of combinations involving three breeds. Comparison of least squares means of various genetic groups revealed that both two breed and three breed crosses were superior to the Nali breed for all wool quality traits. Fibre diameter of MN crossbreds was significantly less than CN crossbreds. Results also indicated that as the inheritance of Nali breed in a cross is decreased, the medulation percentage decreases which is desirable. Inter se mating of crossbreds (two breed, three breed) has not resulted in a decline in the wool quality traits. These results indicate that the synthetic population derived from three breeds can be stabilized easily for wool traits as there may not be epistatic loss on subsequent inter se mating of crossbreds.
Heterosis;Crossbreeding;Epistatic Loss;Synthetic Population;
 Cited by
Bulmer, M. G. 1980. The mathematical theory of quantitative genetics. Clarendon Press Oxford, London

Dickerson, G. E. 1969. Experimental approaches in utilizing breed resources. Anim. Breed. Abstr. 37:191-202

Dickerson, G. E. 1973. Inbreeding and heterosis in animals. Proc. Anim. Breed. Genet. Symp. In honour of Dr. J. L. Lush in Champaign, ILlinois A.S.A., A.D.S.A. 111:54-77

Gani, T. A. S. and R. S. Pandey. 1993. Comparision of wool traits of Rambouillet and its grades with Australian Merino. Ind. J. Anim. Sci. 63:783-784

Kandasamy, N. and K. P. Pant. 1987. Effect of crossbreeding on fleece quality of young sheep under semi-arid region in India. Ind. J. Hered. 19:1-5

Kinghorn, B. P. 1980. The expression of 'recombination loss' in quantative traits. Z. Tierz. Zuchtungsbiol. 97:138-143 crossref(new window)

Kinghorn, B. P. 1982. Genetic effects in crossbreeding. I. Models of merit. Z. Tierz. Zuchtungsbiol. 99:59-68

Kinghorn, B. P. 1983. Genetic effects in crossbreeding. III. Epistasis loss in crossbred mice. Z. Tierz. Zuchtungsbiol. 100:209-222

Kinghorn, B. 1987. The nature of two locus epistatic interaction in animals: Evidence from Sewal Wright's guinea pig data. Theor. Appl. Genet. 73:595-604 crossref(new window)

Kramer, C. Y. 1956. Extension of multiple range test to group means with unequal numbers of replication. Biom. 12:307-310 crossref(new window)

Malik, B. S., B. Singh and M. L. Sangwan. 1991. Studies on fleece production in Nali and its crosses. Ind. J. Anim. Res. 24:82-84

Singh, R. N. 2000. Conservation and management of sheep genetic resources. The Indian J. Anim. Genet. Breed. 22:167-176

Snyman, M. A., G. J. Erasmus, J. B. Van Wyk and J. J. Olivier. 1995. Direct and maternal (Co) variance components and heritability estimates for body weight at different ages and fleece weight in Afrino sheep. Livestock Production Sci. 44:229-235 crossref(new window)

Snyman, M. A., J. J. Olivier and W. J. Olivier. 1996. Variance componenets and genetic parameters for body weight and fleece traits of Merino sheep in arid environment. South-African J. Anim. Sci. 26:11-14

Swan, A. A. and B. P. Kinghorn. 1992. Evaluation and exploitation of crossbreeding in dairy cattle. J. Dairy Sci. 75:624-629 crossref(new window)

Trus, D. and Wilton, J.W. 1988. Dominance model for ram evaluation. Centre for genetic improvement of livestock. Annual Research Report 35-36

Wolf, J. 1995. CBE-General PC Programme for estimating crossbreeding parameters. Pragus, Czech Republic