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...

The technical efficiencies of a sample of extensive Iranian cattle farms collected by Ministry of Agriculture were analyzed using a nonparametric Data Envelopment Analysis (DEA) model. Mean pure technical efficiency in a DEA model in which all variables were normalized with the number of cows was 0.79, indicating that there is ample potential for more efficient input utilization in cattle farmi...

Two experiments were conducted to evaluate responses of primiparous and multiparous Holstein cows to diets containing wet corn gluten feed (WCGF). In both experiments, WCGF replaced a mix of alfalfa hay, corn silage, and corn grain. In experiment 1, 32 primiparous Holstein cows (four pens with eight cows/pen) were used in two 2 x 2 Latin squares with 28-d periods. Cows were housed in free stall...

Objective-To assess the effect of lameness on culling of dairy cows in Tehran province. DesignHistorical cohort study. Study population and procedures7067 firstand second-parity Holstein dairy cows that calved from March, 21 2007 to March, 2

British breeds of cattle are not so effective as Zebu in extracting nutrients from low-quality roughages, and these breeds differ in their nutrient metabolism and animal physiology. Breeds of cattle may differ in their requirements for Mg. Brahman cows are less susceptible to death from disease and metabolic disorders than are British breeds of cattle, whereas cows with 50% or greater dairy bre...

In order to estimate genetic parameters for production traits and reproductive performance, 115 465 records of production traits and 90 942 records of reproductive performance from Iranian Holstein cows that were collected during 1980 to 2004 at Animal Breeding Center of Iran, were used. The estimations were performed using Restricted Maximum Likelihood method (REML) under an animal model by DF...

In pasture-based seasonal calving systems, failure to become pregnant during the breeding season results in important economic losses as maximum profit is attained by minimising costs and increasing the proportion of grass in the diet of the lactating dairy cow. In the United States, dairy producers primarily strive to maximise production potential but are becoming increasingly aware of the eco...

Mastitis is one of the most prevalent diseases in cattle and remains among the most costly diseases to the dairy industry. Various surveys have indicated a greater prevalence of and risk for mastitis in Holstein cows than in Jersey cows. The innate immune system comprises the immediate host defense mechanisms that respond to infection, and differences in the magnitude and rapidity of this respo...

Two experiments were conducted to evaluate seasonal variation in oocyte competence in Holstein cows and to test whether oocyte quality in summer is affected by the magnitude of heat stress. In the first experiment, ovaries of Holstein cows were collected from a slaughterhouse and used to harvest oocytes over 1 yr (n = 18 replicates). After in vitro maturation, fertilization, and culture, propor...