The main objective of this study was to describe Holstein neonatal growth and development as influenced by dietary zinc supplementation and the CD18 genotype, both of which may affect immune competence. Holstein calves (n = 421), after being fed colostrum, were brought to a calf facility, randomly assigned to one of four zinc supplementation groups (control at 40 mg Zn/kg DM or the control diet...

In the Experimental Farm of the Universidade Federal de Lavras (EF-UFLA), state of Minas Gerais, Brazil, on their day of birth, female Holstein calves were randomly selected and placed into two groups containing fifteen animals each: Strategic-Selective Treatment (S-ST) or Conventional Treatment (CT). In the S-ST, calves were treated after coproparasitological examinations according to criteria...

We measured changes in plasma ghrelin and GH concentrations in mature Holstein cows and 3-mo-old female Holstein calves fed at scheduled times. Our objective was to determine the characteristics of ghrelin secretion in dairy cattle and its influence on GH. Animals were fed at 0800 and 1600 for 2 wk before and during experiments. Plasma was sampled for 24 h at 2-h intervals in Exp. 1. In mature ...

Holstein steers have a greater maintenance energy requirement (Zinn and Borquez, 1993) and visceral organ mass (Istasse et al., 1990), and consume approximately 8% more feed than traditional beef steers (NRC, 1987; Fox et al., 1988). Because of their heavy mature weights, Holstein steers calves grow faster than beef steers at comparable weights (Thonney, 1987), capable to increasing their live ...

ity of a beef operation is the percentage of the calf crop weaned, which, in turn, is determined mainly by the number of cows bred during the breeding season. The herd bull influences overall herd fertility more than any other single animal. Because the bull also supplies half of the genetics to all of the calves he sires, bull selection can be the most powerful method of genetic improvement in...

The concentration of immunoglobulin (Ig) G in the blood of neonatal calves shortly after birth is a widely used criterion to determine the degree of acquisition of passive immunity. Another method used to determine the biological mechanisms of IgG absorption is calculation of the apparent efficiency of IgG absorption. Estimation of the efficiency of IgG absorption requires the estimation of pla...

Previous studies have determined that stress causes decreases in feed intake and efficiency in livestock, but the effect of repeated transport on these parameters has not been well studied. This study determined how repeated transport affected calf post-transport behavior, feed intake, ADG, and feed conversion. Thirty-six 4-mo-old Holstein steer calves were housed in groups of 6 with each group...

BACKGROUND Cholesterol deficiency (CD), a newly identified autosomal recessive genetic defect in Holstein cattle, is associated with clinical signs of diarrhea, failure to thrive, and hypocholesterolemia. HYPOTHESIS/OBJECTIVES The objective is to describe the clinicopathological phenotype of affected Holstein cattle homozygous for the causative apolipoprotein B gene (APOB) mutation. ANIMALS...