Dairy cattle are inseminated and pregnancy is established during lactation. Therefore, lactation and the reestablishment of pregnancy must overlap. Unfortunately, recent changes in the genetics, productivity, and management of dairy cows have led to a decline in reproductive efficiency. Reproductive decline in dairy cows began in the mid-1980’s and may be continuing on modern dairy farms (Lucy,...

Dairy cattle are inseminated and pregnancy is established during lactation. Therefore, lactation and the reestablishment of pregnancy must overlap. Unfortunately, recent changes in the genetics, productivity, and management of dairy cows have led to a decline in reproductive efficiency. Reproductive decline in dairy cows began in the mid-1980’s and may be continuing on modern dairy farms (Lucy,...

Leitner, G. 162 INTRODUCTION Economic pressure drives modern dairy farmers to exert continuous efforts to maximize profitability. This is achieved by constant improvement of genetic selection, nutrition, and herd management. Modern dairy farms are characterized by high levels of computerized data acquisition, which provides on-line information on cows' milk yield, milk composition and body weig...

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 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...

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 ...

Background: Metabolic profiles have been used in efforts to predict pre parturient problems and fertility, to diagnose metabolic diseases, and to assess nutritional status in dairy cows. These profiles may help to confirm the diagnosis of sub clinical diseases, to be aware of possible causes of infertility in the herds, or to monitor improvement in herd animals. OBJECTIVES: This study investiga...