Genetic study on productive and reproductive traits by using records first lactation in friesian cows in Egypt
Abstract: A total of 1927 normal first lactation records of Friesian cows were collected from Sakha Farm, Ministry of Agriculture, Egypt during the period from 1968 to 1999 were used in this study. Genetic parameters and breeding values for productive and reproductive traits were analyzed by using multiple-trait animal model analyses of total milk yield trait jointly with reproductive traits. Traits studied were total milk yield (TMY, kg), age at first calving (AFC, month), days open (DO, day) and number service per conception (NSPC, service). Unadjusted means of TMY, AFC, DO and NSPC were 3651 kg, 31.7 month, 204.2 day and 2.1 service, respectively.
Estimates of heritability of TMY, AFC, DO and NSPC were 0.21±0.17, 0.25±0.39, 0.06±0.07 and 0.14±0.21, respectively.
The genetic and phenotypic correlations between total milk yield trait with reproductive traits and between reproductive traits studied were positive and highly significant (p<0.01). The genetic correlation between TMY with AFC, DO and NSPC were 0.39±0.91, 0.42±0.87 and 0.91±0.18, respectively, and between AFC with DO and NSPC were 0.92±0.28 and 0.42±0.98, respectively and DO with NSPC was 0.90±0.68. The phenotypic correlations between TMY with AFC, DO and NSPC were 0.09, 0.32 and 0.09, respectively, and between AFC with DO and NSPC were 0.09 and 0.37, respectively and DO with NSPC was 0.33.
The range of breeding values obtained from multiple-trait analysis of all pedigree animals for TMY, AFC, DO and NSPC were 3651 kg, 31.7 month, 204.2 day and 2.1 service.
Publication year 2007
Pages 379-389
Availability location معهد بحوث الانتاج الحيوانى- شارع نادى الصيد- الدقى - الجيزة
Availability number
Organization Name
City المنوفية
serial title Minufiya Journal Agricultural Research
ISSN 1110-0265
Author(s) from ARC
Agris Categories Animal husbandry
AGROVOC
TERMS		 Animal models. Breeding value. Cows. Egypt. Genetic parameters. Lactation. Milk yield. Production. Reproductive performance.
Publication Type Journal
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