background: cardiovascular system is a very importantorgan that plays a vital role in tissue function. in farm animals,the growth and high milk production depends on function ofcardiovascular system. objectives: cardiovascular health inhigh and low-yielding dairy cows was investigated. methods:fifty 4-year-old high- yielding holstein dairy cows and fifty 4-year-old low- yielding holstein dairy ...

the objective of this study was to determine the optimum replacement strategy using dynamic programming for dairy herds in fars province. a dairy cow is kept several lactations for milk production in the herd. after spending several lactations, milk production gradually begins to decline, while animal health problems rises simultaneously. so one of the most important management decisions of dai...

Introduction In modern dairy cattle operations, antimicrobials are administered for both therapeutic and prophylactic purposes. Most antimicrobials are used therapeutically but some antimicrobials are used to prevent disease in healthy animals during periods of increased susceptibility. Mastitis is one of the most frequent infectious diseases in dairy cattle and accounts for most of the doses o...

The present study has been conducted to evaluate the effect of intramuscular administration of vitamin A during dry period in pregnant dairy cows which have already received it in their daily ration on vitamin A status of neonatal calves. Single intramuscular injection of 2000000 IU vitamin A was carried in 10 dairy cows at 7 months of pregnancy (group 1) and in another 10 dairy cows at 8 month...

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

Replacing cows on a dairy is a major cost of operation. There is a need for the industry to adopt a more standardized approach to reporting the rate at which cows exit from the dairy, and to reporting the reasons why cows are replaced and their destination as they exit the dairy. Herd turnover rate is recommended as the preferred term for characterizing the cows exiting a dairy, in preference t...

Introduction Investigating and comparing the two systems Comparing some technical efficiency ratios and profit Points to note about the comparison Conclusions References Abstract. In this study, budgets of herd dynamics, feed and energy supply, production and profit of alternative dairy farm systems were used to examine the effects of changing a 230 cow Holstein-Friesian (HF) dairy system to a ...

The modern dairy cow has been selected over generations for high milk production, with many successful dairy operations averaging over 13,500 kg of milk per lactation cycle per cow. This amount of nutrient output in the form of milk components puts a tremendous amount of pressure on the metabolism of the dairy cow, especially during early lactation. In fact, it is common to all mammals, includi...

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...

Dairy cow health is multifactorial and complex. High producing dairy cows have been described as “metabolic athletes,” but 30 to 50% of cows are affected by a metabolic or infectious disease around calving (LeBlanc, 2010). Cows are highly susceptible to metabolic and infectious disease during the transition period, or the period from 3 weeks before to 3 weeks after calving (Huzzey et al., 2007,...