Relationships between milk production and some reproductive performances in Friesian cows
Abstract: Milk production and reproduction records of the Friesian herd kept at Sakha Research Station, Animal Production Research Institute, Minister of Agriculture, Egypt, were. used in this study. The data comprised 2400 records of 1336 cows which were the progenies of 153 sires, covering the period from 1984 to 1998. The following milk production and reproductive performances traits were recorded or estimated: 30S-day milk yield (305-dMY); Lactation period (LP); dry period (DP); age at first calving (AFC); days open (DO) and calving interval (CI). The data were analysed using mixed model. procedures.
Heritabilities, genitic and phenotypic correlations among these traits were estimated. Means of 305-dMY, LP, DP, AFC, DO and CI were 2680 kg,.
345 d., 115 d., 32 mo., 165 d. and 460 d. respectively. Least squares analysis of variance showed significant effect of sire on all traits (P<0.0l), except effect of sire on CI was nonsignificant. While effect of cow within sire was significant (P<0.05, P<0.01) on all productive and reproductive traits studied. Effect of season of calving on all traits were non significant, except effect of season of calving on LP was significant.
Effect of year of calving and parity on all traits were significant (P<0.05, P<0.01), except effect of parity on DP was non significant.
Heritability estimates for all traits studied were 0.38 for 305-dMY;
0.30 for LP; 0.03 for DP; 0.32 for AFC; 0.21 for DO and 0.20 for CI.
Genetic correlation between any two traits studied was significant (P<0.05 or P<0.01), except between age at first calving and Lactation period. Phenotypic correlation between any two traits studied was significant P<0.05 or P<0.01), except between LP and both AFC and DP.
It could be concluded from the present study that the managerial level as well as the appropriate environmental conditions have great impacts on milk production and reproduction traits of the imported Friesian cattle raised under-the government farms in Egypt.
Publication year 2003
Pages 21-33
Availability location معهد بحوث الانتاج الحيوانى- شارع نادى الصيد- الدقى - الجيزة
Availability number
Organization Name
serial title Egyptian Journal of Applied Science
ISSN 1110-1571
Author(s) from ARC
Agris Categories Animal husbandryAnimal physiology - Reproduction
AGROVOC
TERMS		 Cows. Milk production. Parturition. Reproductive performance. Seasons.
Publication Type Journal
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