University of Khartoum

Genetic and Phenotypic Influences in a Herd of Kenana Cattle

Genetic and Phenotypic Influences in a Herd of Kenana Cattle

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Title: Genetic and Phenotypic Influences in a Herd of Kenana Cattle
Author: Mohammed Hamdi Bur, Omer
Abstract: This study was conducted to estimate the effects of some environmental and genetic factors on the reproductive and milk production traits of Kenana cattle in the Sudan. In part, it was also intended to estimate the genetic parameters for these traits in an attempt to explore the possibilities of improvement and conservation of this breed. The study included 110 Kenana records from Um Benein Livestock Research Station covering the years 1970 to 2001. The records were analyzed using Harvey's Least Squares Computer Program (1990). The least squares means for Age at first calving, calving interval, lactation milk yield, daily milk yield, lactation length and dry period were 61.85±2.24 months, 410.62±9.67 days, 1399.15±187.48 kg, 4.70±0.7 kg, 297.12±12.46 days and 96.48±:9.67days, respectively. The analysis of variance revealed that year-season of calving influence the age at first calving, daily milk yield and lactation length (p<0.0I). Parity number of cow had a significant effect (p<0.0I) on lactation length. The sire of the cow had a significant effect (p<0. 01) on age at first calving, lactation mil yield, daily milk yield and lactation length. Heritabilities were estimated by paternal half-sib analysis and the estimates were 0.28±0.16, 0.13±0.12, 0.36±0.34, 0.35±0.23 and 0.13±0.12 for age at first calving, calving interval, lactation yield, lactation length and dry period, respectively. Genetic, phenotypic and environmental correlations were estimated by paternal half-sib analysis of variance and covariance. The genetic correlations were 0.82±0.09 for lactation milk yield and daily milk yield, 0.28±0.31 for lactation milk yield and lactation length, 0.004±0.28 for daily milk yield and lactation length. The environmental correlations between the same traits were -0.24, 0.29 and -0.27. The phenotypic correlations were 0.77, 0.26, 0.05, 0.51 and 0.58 for lactation milk yield and daily milk yield, lactation milk yield and lactation length, daily milk yield and lactation length, calving interval and dry period and dry period and lactation length.
URI: http://khartoumspace.uofk.edu/handle/123456789/14422
Date: 2015-06-23


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