Postpartum anestrous is one of the most important problems in the dairy industry in the world and especially in Iran. The objective of present study was to compare the efficacy of two hormonal programs for recycling of postpartum anestrous cows. For this reason, 230 Holstein cows from 4 similar dairy herds (with totally 2560 cow and unique management and feeding system) located on the suburb of...

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 evaluate a mobile computerized grain feeder for use to feed individually Holstein cows grazing grass pasture. Thirty-two Holstein cows averaging 95 d of lactation and 39.3 kg/d of milk were rotationally grazed on predominantly Dactylis glomerata pastures for 9 wk starting in early May. Cows were blocked according to parity, days of lactation, and milk yield. C...

The goal of this study was to determine whether oral administration of sodium phosphate in conjunction with intravenous calcium is more efficaceous than intravenous calcium alone for the treatment of parturient paresis. Thirty cows with parturient paresis were examined and treated by the same veterinarian. The cows were divided randomly into two groups of 15 cows each. Cows in group A received ...

Thirty two multiparous Holstein cows were used in a randomized block design to investigate the effects of feeding diets included two different source of nonfiber carbohydrate during the transition period on dry matter intake (DMI), lactational performance, blood metabolites and parturitional characteristics. Cows received total mixed rations containing either macaroni wastes(MW) or steam-flaked...

The aim of this study was to examine virulence factors and the ability of S. aureus and CNS species isolated from milk of cows with mastitis to form biofilm, and to compare them with virulence factors of staphylococci from milk of cows without mastitis and cowshed environment. Most of S. aureus strains from cows with mastitis showed haemolytic activity (93.9%), among them 72.7% and 21.2% produc...

A prospective cohort study was undertaken in two commercial California dairies. The treatment group, 246 cows, received three doses of a whole cell bacterin of J5 Escherichia coli (mutant of E. coli O111:B4) plus Freund's incomplete adjuvant vaccine (two in the dry period and one after calving) while 240 unvaccinated cows served as controls. Thirty-five cases of clinical coliform mastitis were ...

Three experiments were conducted to evaluate the effects of biostimulation (exposure to bulls or androgenized females) on various reproductive variables in suckled beef cows. Bulls or testosterone-treated cows (TTC) were introduced to cows, randomly allotted to one of four groups, within 72 h postpartum. In Exp. 1, Groups 1 and 3 were exposed to bulls and Groups 2 and 4 were exposed to TTC. In ...

Electrocardiography (ECG) may be used to recognize cardiac disorders. Levels of milk production may change the serum electrolytes which its imbalance has a role in cardiac arrhythmia. Fifty high yielding and fifty low yielding Holstein dairy cows were used in this study. Electrocardiography was recorded by base-apex lead and blood samples were collected from jugular vein for measurement of seru...

Poor reproductive efficiency is a worldwide problem that has affected the dairy industry during the last several decades. In an attempt to explain the changes in reproductive physiology caused by high milk production, a model of elevated steroid metabolism in lactating dairy cows has been proposed. A slow increase in levels and low peak levels of estradiol (E₂) and progesterone (P₄) characteriz...