A STUDY ON PRODUCTION AND REPRODUCTION TRAITS OF FRIESIAN CATTLE IN EGYPT | ||||
| Journal of Animal and Poultry Production | ||||
| Article 2, Volume 27, Issue 11, November 2002, Page 7281-7289 PDF (8.73 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jappmu.2002.257096 | ||||
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| Authors | ||||
| A. A. Shitta,; M. A. Tag EI-Dien; Set EI-Habaeib S. Awad | ||||
| Animal Production Research Institute, Ministry of Agriculture, Giza, Egypt. | ||||
| Abstract | ||||
| A total of 1834 lactation records of Holstein cows were used for studying the random effects of sire and cow within sire and the fixed effects of year of calving, month of calving and parity on 305 day milk yield (305-dMy), lactation period (LP), dry period (DP), days open (DO), number of service per conception (NSPC) and calving interval (CI). Least squares analysis of variance showed significant effect of sire on 305- dMY only (P<O.01), while effect of cow within sire was significant (P<O.01) on all productive and reproductive traits studied. The effect of fixed factors were mostly significant (P<0.05) & (P<OJ'1). The partial linear regression coefficients of DO and DP on 305-dMY were 11.31±O.5 kg/d (P<O.O·I) and -10.93±O.83 kg/d (P<O.01) respectively, which indicate that reduction in dry period is considered if it is a desirable goal for dairymen. Heritability estimates were moderate for 305-dMY and LP (0.33 and 0.19 respectively) and extremelly low for DP, DO, CI and NSPC (0.02.0.01.0.02 and 0.01), respectively. Most estimates of genetic correlation were nearly similar to the corresponding estimates of phenotypiC correlation in values having the same direction. | ||||
| Keywords | ||||
| Friesian cattle; Production and reproduction traits; genetic and non genetic factors | ||||
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