ABSTRACT:
Dietary chromium supplementation before, during, and after weaning was conducted to evaluate the hypothesis that chromium supplementation could reduce weaning-induced cortisol release in beef calves. We examined the effects of chromium supplementation in 150 crossbred calves (male and female) between five and six months of age. The calves were randomly divided by sex and breed into two equal homogeneous groups (n=75). One group was used as the control, and the other experimental group received supplementation with 0.9mg of chromium carbon-amino-phospho-chelate per 100kg BW. The chromium supplement was mixed with mineral salt for the consumption of 0.1% of BW, and the supplement was administered via creep feeding 60 days before and 60 days after forced weaning. Calves were weighed, and their blood and urine samples were obtained at four time-points: T0 (60 days before weaning), T1 (at weaning), T2 (48 hours after weaning), and T3 (60 days after weaning). Blood samples were used to determine chromium, cortisol, total protein, and albumin concentrations, and urine samples were used to determine urinary creatinine and chromium levels. Cumulative weight gain was higher in calves supplemented with chromium before weaning and during the experiment (P<0.05). In addition, weaning-related stress caused an increase in chromium excretion in the urine, and chromium supplementation reduced stress, which resulted in lower cortisol and total protein levels during weaning.
INDEX TERMS:
Organic chromium; supplementation; beef calves; weaning stress; cattle; performance; stress; mineral supplementation; chromium