TY  - JOUR
T1  - The Association Between Production and Reproduction Traits in Some Iranian Holstein Herd
AU - , Reza Seyed Sharifi AU - , Taher Yalchi AU - , Raouf Seyed Sharifi AU - , Bahram Fathi Achachlouei 
JO  - Research Journal of Biological Sciences
VL  - 3
IS  - 12
SP  - 1463
EP  - 1467
PY  - 2008
DA  - 2001/08/19
SN  - 1815-8846
DO  - rjbsci.2008.1463.1467
UR  - https://makhillpublications.co/view-article.php?doi=rjbsci.2008.1463.1467
KW  - Days open
KW  -days dry
KW  -fertility
KW  -milk yield
KW  -holsteins
AB  - The objective of this study was to evaluate the relationship between reproductive performance and milk yield in some Iranian Holstein cattle that calved from 2000-2004. Results for current days open for the first lactation indicated a curvilinear relationship with milk yield. These results agree with the accepted management recommendation of a 60 days dry period. Most estimates of heritability of various measures of reproductive efficiency are less than 0.05. The reproductive trait with the highest heritability, 0.096, was previous days dry in the third lactation. Genetic correlations between milk production and reproduction traits were generally positive. Phenotypic correlations were larger than genetic correlations. Genetic correlations among cow fertility in second and third lactations were inclined to be lower than in first lactation, whereas the phenotypic correlations tended to be of the same magnitude and direction in all three lactations.
ER  -