to describe proportion and pattern of culling in commercial dairy herds of khorasan razavi province, this survey was carried out from 21st march 2008 to 20th march 2009 in 15 industrialized dairy herds. for each culled cow data related to parity at culling, last calving to culling interval and primary reason for culling were recorded. annual herd exit rate was 20.9%. out of a total of 652 culle...

In this study, the incomplete gamma function, an exponential function, a mixed-log function and a polynomial function were evaluated to describe the lactation curve in Moroccan Holstein-Friesian dairy cows. Data from 1990 to 1999, comprising 77130 monthly milk yields of 6029 dairy cows in 280 dairy herds, were used. Edits were carried out by considering the lactation length (5 d and

Excellent reviews of cattle breed comparisons or breed-cross comparisons have been previously reported by Franke (1980), Long (1980), and Marshall (1994). However, these reviews do not contain information on the calving ease, performance, carcass characteristics, or beef palatability of crossbred progeny of Holstein dams sired by different beef breeds. In many countries dairy females are common...

BACKGROUND Over two decades of observations in the field in South East Asia and Hawai'i suggest that majority of the commercial dairy herds are of black hair coat. Hence a simple study to determine the accuracy of the observation was conducted with two large dairy herds in Hawaii in the mid-1990s. METHODS A retrospective study on longevity of Holstein cattle in the tropics was conducted using...

in this study, the incomplete gamma function, an exponential function, a mixed-log function and a polynomial function were evaluated to describe the lactation curve in moroccan holstein-friesian dairy cows. data from 1990 to 1999, comprising 77130 monthly milk yields of 6029 dairy cows in 280 dairy herds, were used. edits were carried out by considering the lactation length (5 d and

mastitis in cattle is a serious problem which causes considerable economic losses in the dairy cattle herds. the aim of this survey was to identify mycoflorain milk of healthy, clinical and subclinical mastitis of lactating holstein dairy cows. milk samples of 154 holstein dairy cows were collected from 10 dairy cattle herds in suburb of mashhad-iran. the treatment groups included 104 lactating...

The relationship of first score and length of life in the herd was measured in Holstein females two or three years of age at first classification. The regression of herd life (number of times classified) on the first over-all type score (nearly all values were between 65 and 90 points) was 1.7 months. Correlation between first classification score and herd life was approximately 0.2, indicating...

 In US dairy herds, the current national average age at first calving is 25.2 months. Increasing first-lactation milk yield could improve milk’s life-cycle production efficiency and decrease emissions.  The productive life of dairy Holsteins in the United States born in 2000 decreased by 3.95 months compared with Holstein cows born in 1980. This negative trend needs to be halted to achieve en...

the objective of this study was to explore the reproductive consequences of using sex-sorted semen on sex ratio, conception rate and reproductive disorders (dystocia, abortion, stillbirth) in holstein heifers. reproduction performances records which were collected during 2006 to 2013 from 4 large dairy herds in isfahan province of iran were used and analyzed by genmod procedure of sas software....