GENETIC ANALYSIS OF SOME PRODUCTIVE AND REPRODUCTIVE TRAITS OF FIRST LACTATION OF FRIESIAN CATTLE RAISED IN EGYPT | ||||
| Journal of Animal and Poultry Production | ||||
| Article 4, Volume 4, Issue 2, February 2013, Page 97-106 PDF (762.69 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jappmu.2013.71012 | ||||
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| Authors | ||||
| N. A. Shalaby1; A. S. A. El-Barbary2; E. Z. M. Oudah1; M. Helmy1 | ||||
| 1Dept. of Animal Production, Fac. Agric., Mans. Univ. PC: 35516, Mansoura, Egypt. | ||||
| 2Dept. of Animal Production, Fac. Agric., Alex. Univ. PC: 21545, Egypt. | ||||
| Abstract | ||||
| Data used in this investigation were collected from 4370 records relevant to 874 purebred Friesian cows which belong to Shobratana Animal Production Society, located in the north part of Delta region near Tanta city in Egypt. These cows were daughters of 43 sires. The records used covered the period from 1985 to 2003. The following six productive and reproductive traits of the first lactation were analyzed: Total Milk Yield (TMY, kg), dry period (DP, day), lactation length (LL, day), days open (DO, day), calving interval, (CI, month) and age at first calving (AFC, month).sire random effect and month and year fixed effect. Data were analyzed using Linear Mixed Model Least Squares and Maximum Likelihood (LSMLMW) computer program of Harvey (1990). The overall means of TMY, DP and LL were 5387 kg, 72.9 days and 327 days, respectively. The overall means of CI, DO and AFC were 13.4 month, 121 days and 27.8 month, respectively. Heritability estimates for TMY, DP, LL, CI, DO and AFC were 0.141±0.074, 0.109±0.069, 0.040±0.057, 0.104±0.068, 0.202±0.084 and 0.217±0.087 respectively. The ranges of breeding values of all sires in the pedigree for TMY, DP, LL, DO and CI were 685 kg, 18 day, 8.15 day, 48.2 day and 1.05 month, respectively. Spearman rank correlations and Pearson correlations among estimated breeding values of all sires in pedigree provided by the genetic analysis ranged between -0.712 to 0.907. The objectives of the present study were: 1) to estimate some genetic and non-genetic factors affecting productive and reproductive traits, 2) to estimate genetic and phenotypic parameters for these traits and 3) to estimate breeding values for sire Friesian cows in this farm. Rank correlations of animals between traits were the lowest for reproduction traits. It could be concluded that improving the environmental conditions will improve these traits. | ||||
| Keywords | ||||
| Friesian cows; genetic parameters; Breeding value; BLUP; Egypt | ||||
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