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...

Blood metabolic profiles were determined from 40 days prepartum to 60 days postpartum in Uruguayan Holstein (UH) (n = 13) and UH x New Zealand Holstein-Friesian first cross (UH-NZHF) (n = 13) cows with seven in each group experiencing their second lactation (L2) and six experiencing their third lactation (L3). Non-esterified fatty acids increased around calving and tended to be greater in UH-L3...

Variation in animal personality, in other words, behavioural responses consistent within individuals over time and/or across contexts, is predicted to be related to life-history traits, such as growth rate and investment in reproduction. How this translates into relationships between personality and milk production in dairy cows is however scarcely investigated and previous studies are showing ...

A total of 50 adult cows each of Friesian and Jersey breed maintained at the Livestock Experiment Station Bhunikey (Pattoki) District Kasur were selected randomly for this study. Blood smears of all animals were prepared aseptically through standard procedure. The cows found positive for theileriasis were treated with Buparvaquone (Butalex) injection @ 5 ml/100 Kg b. wt. intramuscularly, while ...

The composition and physical nature of milk is very complex. The stability of milk depends upon the different constituent of milk. Determination of heat stability of milk is one of the factors that assess the stability of milk. In this study an attempt was made to measure the heat stability of milk obtained from different varieties of cows and also made an attempt to identify the different comp...

Background: Evaluation of energy metabolism indices in mid-lactation Holstein cows is critical to monitor health status. Aims: The objective of this study was to assess the effects of low (≤0.75) vs. high (>0.75) drops in body condition score (BCS) until day 60 post-partum on energy metabolism indices during mid-lactation in Holstein cows. Meth...

Our objective was to compare the effects of different prepartum dietary phosphorus concentrations on periparturient metabolism and performance. Forty-two late pregnant multiparous Holstein cows were fed 0.21, 0.31, or 0.44% P (dry basis) for 4 wk before expected calving. After parturition, all cows were fed a common lactation diet (0.40% P). In the prepartum period, cows fed 0.21% P had lower b...

the present study aimed to estimate the effects of parity, calving season and year of calving on the prevalence of subclinical mastitis in holstein cows. a total of 2682 records from 869 holstein cows in a large dairy farm (azarbaijan province, iran), respecting the period from 2006 to 2009, were collected. data was analyzed using proc mixed of sas software by mivque method. subclinical mastiti...