Effect of Dietary Chromium Supplementation in Transition Calves on Insulin Sensitivity and Biomarkers of Rumen Development

A study of 100 days using calves in transition phase of growth (15 to 115 days) was conducted. 24 Hariana calves were randomly assigned to four groups of six each and fed on diets without supplemental chromium (Cr) as control or 0.05 mg, 0.10 mg, and 0.15 mg Cr/kg BW^0.75 groups. Treatment had no significant effect on the average daily gain (ADG) and body condition score (BCS). Plasma glucose, insulin, insulin: glucose ratio, and insulin receptor substrate – (IRS-1) as biomarkers of insulin sensitivity while â-hydroxy butyrate (BHBA) and insulin like growth factor -1 (IGF-1) as biomarkers of rumen development were studied on 0, 30, 60, 70, 80, 84, 86, 87, 88, 89, 90, 95, and 100 days post-Cr supplementation. Plasma glucose and insulin concentrations decreased (p < 0.05) with the advancement of age of calves and their levels were lowest (p < 0.01) in the calves supplemented with highest Cr level (0.15 mg of Cr/kg BW^0.75). The insulin: glucose ratio was higher (p < 0.05) in the calves supplemented with Cr. Treatment, period and treatment × period interaction had a significant effect on plasma IRS-1 concentration as its concentration increased with the increase in supplementation level of Cr. Treatment and treatment × period interaction had non significant on plasma BHBA and non-esterified fatty acids (NEFA) levels while period had significant effect on BHBA (p<0.05 and NEFA (p<0.01) concentrations. However, a significant effect of treatment, period, and treatment × period interaction on plasma IGF-1 concentrations was observed with higher(p< 0.01) plasma IGF-1 concentration in 0.15 mg of Cr/kg BW^0.75 supplemented calves. In conclusion, the dietary supplementation of Cr was beneficial in improving insulin sensitivity and modulating biomarkers of rumen development of calves during the transition period from pre-ruminant to ruminant phase.