- Turkish Journal of Veterinary and Animal Sciences
- Volume:29 Issue:1
- Effect of Certain Factors on Productive and Reproductive Efficiency Traits and Phenotypic Relationsh...
Effect of Certain Factors on Productive and Reproductive Efficiency Traits and Phenotypic Relationships Among These Traits and Repeatabilities in West Anatolian Holsteins
Authors : Mustafa TEKERLİ
Pages : 17-22
View : 7 | Download : 6
Publication Date : 0000-00-00
Article Type : Research Paper
Abstract :The present investigation was undertaken to study certain factors affecting production efficiency, milk production and reproduction and to estimate the repeatabilities and phenotypic correlations of these traits in Holsteins maintained at different farms in western Anatolia over 3 years insert ignore into journalissuearticles values(1990 - 1993);. The data consisted of 506 first and 232 second lactations of 525 cows. Three production efficiency traits insert ignore into journalissuearticles values(milk yield per day of lactation length insert ignore into journalissuearticles values(MYPDLL);, milk yield per day of calving interval insert ignore into journalissuearticles values(MYPDCI); and milk yield per day of age at second calving insert ignore into journalissuearticles values(MYPDASC););, one production trait insert ignore into journalissuearticles values(lactation yield insert ignore into journalissuearticles values(LY););, and one reproduction trait insert ignore into journalissuearticles values(calving interval insert ignore into journalissuearticles values(CI);); were studied. The means of MYPDLL, MYPDCI, MYPDASC, LY and CI were 19.04 kg, 15.44 kg, 4.91 kg, 6404.77 kg, and 418.86 days, respectively. The analyses of variance indicated that the effects of the region-year factor were significant insert ignore into journalissuearticles values(P < 0.05); for all traits, whereas none of the traits was influenced by the parity order. The calving months were significant insert ignore into journalissuearticles values(P < 0.05); for MYPDASC, LY and CI. Least-squares means illustrated that these traits were lower for summer calvers. Age also had an important effect insert ignore into journalissuearticles values(P < 0.05); on MYPDLL, MYPDCI and LY. The positive phenotypic correlation insert ignore into journalissuearticles values(0.55); between milk yield and calving interval suggested that the higher yielding cows had longer calving intervals. Fertility was also severely depressed when the lactation yield was higher than 7000 kg. The repeatabilities for MYPDLL insert ignore into journalissuearticles values(0.51);, MYPDCI insert ignore into journalissuearticles values(0.41); and LY insert ignore into journalissuearticles values(0.43); were high, and low for calving interval insert ignore into journalissuearticles values(0.10);.Keywords : Milk production, production efficiency, reproduction, phenotypic correlation, repeatability, Holstein