The objective of this study was to compare the effects of rearing calves outdoors, with and without all-weather calf jackets, with calves reared indoors on calf immunity and animal performance. In February 1999, male Holstein calves (mean (s.e.) weight 55 (1.90) kg) were randomly assigned to one of three treatments (n=30 per treatment): 1) outdoors with jacket, (J; mean age 19 (s.e. 2.0) days);...

The objective of this study was to compare active drug concentrations in the plasma vs. different effector compartments including interstitial fluid (ISF) and pulmonary epithelial lining fluid (PELF) of healthy preruminating (3-week-old) and ruminating (6-month-old) calves. Eight calves in each age group were given a single subcutaneous (s.c.) dose (8 mg/kg) of danofloxacin. Plasma, ISF, and br...

I. Eighty bull calves, comprising forty-eight Ayrshire and sixteen each of the Friesian and Jersey breeds, were used in a randomized block experiment. Forty calves were maintained at a mean environmental temperature of 21' and forty at 14.5'. Within each temperature, twenty calves were reared from birth on a liquid milk substitute diet (pre-ruminant calves) and twenty were weaned at 35 d of age...

The immunizing effect of inactivated sporulated oocyst and inactivated sonicated vaccines against bovine coccidiosis was observed in calves. Indirect haemagglutination (IHA) test was developed for detecting antibodies to coccidian. Serum antibody levels in calves were measured against soluble oocyst (sporulated) antigen. IHA antibody titer was significantly higher (P<0.05) in calves vaccinated ...

In the present study, the potential benefits of feeding pasteurized colostrum were demonstrated in calves born to dams naturally infected with Mycobacterium avium ssp. paratuberculosis. Calves were separated at birth from their dams and randomly allocated into a group fed either the colostrum of their dam (DC; n = 6), followed by feeding the milk of the dam for 3 wk and then milk replacer, or i...

The post-operative effects of three formulations of topical anaesthetic and a cornual nerve block on the sensitivity of scoop dehorning wounds in calves were compared in two trials. In Trial 1, 21 female Holstein dairy calves aged 8 to 24 weeks were randomly allocated to two groups: (1) scoop dehorning with a post-operative application of a novel topical anaesthetic powder (DTAP, n = 10); and (...

Crossbred calves (n = 572; initial BW = 186 +/- 27 kg) purchased from northern Texas, Arkansas, and southeast Oklahoma auction markets were delivered to the Willard Sparks Beef Research Center, Stillwater, OK, and used to study the effects of dietary energy and starch concentrations on performance and health of newly received feedlot calves during a 42-d receiving period. On arrival, calves wer...

T-cell control of primary rotavirus infection and mucosal antibody responses to rotavirus was studied with monoclonal antibodies (MAb) to deplete gnotobiotic calves of CD4+, CD8+, BoWC1+, or both CD4+ and CD8+ lymphocytes prior to infection with rotavirus. Injection of these MAb produced specific reductions in circulating and tissue lymphocyte subpopulations. Following infection, control calves...

A mating plan was designed to test the genetic hypothesis that atresia coli is inherited as an autosomal recessive at a single locus with two alleles. Matings between 8 putative carrier sires and 56 putative carrier dams resulted in 59 normal and 8 atresia coli calves, which was not different from the expected number of 8.1 affected calves. One case of atresia coli was observed among 628 calves...