Feeding dairy cows for maximum milk production increases the risk of ruminal acidosis. Diets fed to high producing dairy cows in North America are typically highly digestible in the rumen and often lack sufficient physical fiber. Rapid fermentation of carbohydrates causes an accumulation of volatile fatty acids (VFA) in the rumen, leading to a drop in ruminal pH. Lack of sufficient physical fib...

Managers of high producing dairy herds have known for some time that optimizing reproductive efficiency is an essential issue in maintaining profitability of a dairy herd. A recent survey by the University of Wisconsin Center for Dairy Profitability asked a random sample of 2,700 dairy producers in Wisconsin to rank the importance of different dairy issues to the future profitability of their b...

The objectives were to evaluate effects of human chorionic gonadotropin (hCG) (3,300 IU i.m.) administered on d 5 after AI on CL number, plasma progesterone concentration, conception rate, and pregnancy loss in high-producing dairy cows. Following the synchronization of estrus and AI, 406 cows were injected with either hCG or saline on d 5 after AI in a randomized complete block design. Blood s...

OBJECTIVE To examine the effects of Rhodobacter sphaeroides (R. sphaeroides) supplementation as a direct-fed microbial (DFM) on rumen fermentation in dairy cows and on coenzyme Q10 (CoQ10) transition into milk, an in vitro rumen simulation batch culture and an in vivo dairy cow experiment were conducted. METHODS The characteristics of in vitro ruminal fermentation were investigated using rume...

Efficient reproduction is important for optimal profitability on dairy operations. Unfortunately, most dairy farms do not attain optimal reproduction due to many factors related to management, health, and physiology of high-producing dairy cows. The physiology issues involved in reproduction of lactating dairy cows are complex but increasingly, the interactions between nutrition, the hormonal s...

Milk yield and its composition vary according to individual cows as well as to a variety of different environment conditions, such as temperature. Previous studies suggest that heat exerts considerable negative effects on milk production and its composition, especially during summer months. We investigate the production and fat composition of milk from individual dairy cows and develop a modell...

Subacute ruminal acidosis (SARA) has been considered a major pathology in high producing dairy herds for years. These findings were corroborated by several studies in Europe. However, different feeding practices and herds’ production levels are found in Southern Belgium. This study aimed to ascertain whether dairy cows of several herds from the south of Belgium (Wallonia) with a suspicion of SA...

Reproductive failure in inseminated cattle results from poor fertilization and embryo survival. Recent studies utilizing dairy and beef cattle indicate that fertilization rates are higher for nulliparous dairy and beef heifers and nonlactating beef cows than lactating beef and dairy cows and nonlactating dairy cows. Several factors affect fertilization rates, but the greatest impact was observe...

The objective of this study was to examine the effect of an excess intake of quickly degradable nitrogen (QDN) on ovarian follicle development. Twenty lactating dairy cows were fed mixed silage and concentrates twice daily. The control diet was a typical ration for high producing dairy cows in the United Kingdom (crude protein (CP)=17.5%; metabolizable energy (ME)=11.8 MJ/kg DM). The cows were ...