Background: The goal of this study was to evaluate the effect of hypoxia on intestinal permeability and cardiopulmonary physiology in 2-month old calves. Methods: Calves were exposed to normoxic (975 m altitude; controls) or hypoxic (4,570 m altitude) conditions for 2 weeks. Pulmonary arterial pressures and intestinal permeability to mannitol and lactulose were assessed on Days 0 and 14. Calves...

BACKGROUND Mycobacterium avium subsp. paratuberculosis (MAP), the agent of Johne's disease in cattle, is a facultative intracellular bacterium that is dependent on ferric iron for its survival and replication. Gallium (Ga), a trivalent semimetal that shares many similarities with ferric iron and functions as an iron mimic has been shown to have in vitro antimicrobial activity against several mi...

To determine the effects of castration of calves, with or without local anesthesia, on plasma cortisol, scrotal circumference, ADG, and ADFI, 56 Friesian bulls (5.5 mo of age; mean +/- SE BW = 173 +/- 2 kg) were randomly assigned to each of seven treatments: 1) control (CON); 2) s.c. injection of .1 mg of a human serum albumin-GnRH conjugate with DEAE-dextran adjuvant (HSA-GnRH); 3) burdizzo ca...

The present study was conducted to evaluate the effects of physical form of starter and alfalfa hay (AH) provision on growth performance, ruminal fermentation, and blood metabolites of Holstein dairy calves. Forty-four 3d-old Holstein dairy calves with a mean starting BW of 39.9 ± 1.1 kg were used in a 2 × 2 factorial arrangement. The factors were dietary forage level (0 or 150 g kg-1</sup...

The role of bile in manganese metabolism and homeostasis was studied in Holstein bull calves fed diets containing 32 ppm manganese (normal) (control) or 1,000 ppm supplemental manganese (high-manganese) for 2 weeks before and 1 week after intravenous (IV) and duodenal S4Mn dosing. After dosing, all the bile was collected at 15 and 60 minutes, hourly to 12 hr and daily to 7 days. All calves were...

Foot-and-mouth disease virus (FMDV) infected animals can contaminate the environment with their secretions and excretions. To quantify the contribution of a contaminated environment to the transmission of FMDV, this study used calves that were not vaccinated and calves that were vaccinated 1 week prior to inoculation with the virus in direct and indirect contact experiments. In direct contact e...

Rodents and primates deprived of early social contact exhibit deficits in learning and behavioural flexibility. They often also exhibit apparent signs of elevated anxiety, although the relationship between these effects has not been studied. To investigate whether dairy calves are similarly affected, we first compared calves housed in standard individual pens (n = 7) to those housed in a dynami...

Sodium bicarbonate and yeast culture effects on ruminal fermentation, intake, and growth were evaluated in young calves. In trail 1, nine ruminally cannulated Holstein calves averaging 12 wk of age were fed control starter (17% CP) or starters containing 3% sodium bicarbonate or .2% yeast (Saccharomyces cerevisiae) culture in a 3 x 3 Latin square. Calves were fed for ad libitum consumption for ...

A total of 275 steer calves from 17 farms in Tennessee were used to study the influence of pretransit management and posttransit B vitamin supplementation on calf performance and health. Pretransit treatments were : (1) weaned the day of sale and fed hay at the order buyer barn (Control C), (2) weaned the day of sale and fed a 50% concentrate, high antibiotic diet in an order buyer barn for 3 d...

The objectives of this study were to evaluate the effects of intravenous acetate Ringer's solution, with or without dextrose, on diarrheic calves with either experimentally induced or spontaneous diarrhea. In the experimental model, diarrhea was induced in nine healthy calves by administering cold milk (below 4°C) twice a day for 2 days. The calves were randomly assigned to the isotonic saline ...