The objective of this experiment was to evaluate the effects of bovine somatotropin administration on serum concentrations of glucose, insulin, NEFA, IGF-I, and progesterone (P4) in ovariectomized non-lactating dairy cows receiving exogenous P4, as a model to estimate treatment effects on hepatic P4 degradation. Ten non-lactating, non-pregnant, and ovariectomized Gir Holstein cows were assigned...

A total of 45 lactating Holstein cows averaging 617 kg of BW were allotted at wk 20 of lactation to 9 groups of 5 cows blocked for similar DIM to determine the effects of feeding different concentrations of flax hulls (FH) on DMI, milk production, milk composition, and digestion. Cows within each block were assigned to one of the 5 isoenergetic TMR containing 0, 5, 10, 15 or 20% FH. The experim...

Dietary Zn and heat stress alter gut integrity in monogastric animals. However, effects of Zn on mammary epithelial integrity in heat-stressed lactating dairy cows have not been studied. Multiparous lactating Holstein cows (n = 72) were randomly assigned to 1 of 4 treatments with a 2 × 2 factorial arrangement to study the effects of environment and Zn source on performance and mammary epithelia...

the present study was conducted in order to determine the effects of feeding frequency (ff) on dairy cow performance fed a total mixed ration (tmr) based on chopped alfalfa hay. eight multiparous early lactation holstein cows were housed in the individual boxes (4 × 3 m) and fed either once a day (1x) at 0700 h or 4 times a day (4x) at 0100, 0700, 1300 and 1900 h with tmr. the experiment was do...

Background: Presynchronization could enhance fertility in timed breeding programs. The best presynchronization method has to justify biological requirements and to provide practical and economic advantages. OBJECTIVES: Present study investigated the effectiveness of presynchronization with equine chorionic gonadotropin (eCG) before ovsynch (eCG-ovsynch) compared to conventional presynch-ovsynch...

Ruminants make efficient use of diets that are poor in true protein content because microbes in the rumen are able to synthesize a large proportion of the animal’s required protein. The amino acid (AA) pattern of this protein is of better quality than nearly all of the dietary ingredients commonly fed to domestic ruminants (Broderick, 1994; Schwab, 1996). In addition, ruminal microbial utilizat...

Ingestion of high levels of rapidly fermented carbohydrates after parturition often leads to the production of excessive quantities of organic acids that may exceed the buffering capacity of the rumen and cause pH to drop. Ruminal acidosis results in animal discomfort, anorexia, depression, decreased digestibility, and decreased milk production. In the present study, we examined the effects of ...

Four treatments were assigned to determine the effects of dietary potential digestible fiber (pdF) and crude protein (CP) levels in mid lactating Holstein cows on milk production and nitrogen efficiency. Sixteen primiparous (n=8) and multiparous (n=8) Holstein cows (body weight (BW)=546±72 kg; days in milk (DIM)=118±50 day) were allocated to one of four diets in balanced randomized complete des...

The objective of this study was to characterize opinions and practices of Wisconsin dairy producers about biosecurity and animal wellbeing. Wisconsin dairy producers were surveyed using a mailed questionnaire and responder herds were categorized based on the number of lactating cows: very small herds (< or =50 lactating cows; n = 279); small herds (51 to 100 lactating cows; n = 202); medium her...