Dietary Chromium Picolinate Supplementation Improves Glucose Utilization in Transition Calf by Ameliorating Insulin Response.

The decrease in insulin sensitivity during the transition of preruminant calves into ruminant animals is the common denominator. Meanwhile, this adaptation predisposes dairy calves towards various health issues and metabolic disorders that occur in later life. Chromium (Cr) has been shown to potentiate insulin functioning and is thereby helpful in reducing the risk of these metabolic disorders. The aim of this study was to assess the effect of Cr supplementation on the insulin sensitivity and health status in Hariana calves during their transition period. A total of 24 preruminant Hariana calves were randomly allocated into four groups (6 calves per group) for a period of 90 days. Calves either received a basal diet devoid of supplemental Cr (control; Cr0.0 group) or were supplemented with 0.05 mg (Cr0.05 group), 0.10 mg (Cr0.10 group), and 0.15 mg (Cr0.15 group) of Cr per kg BW0.75 as Cr-picolinate (Cr-Pic). To determine the effect of Cr supplementation on the insulin response, glucose-insulin-non-esterified fatty acids (NEFAs) kinetics was studied during the intravenous glucose tolerance test (IVGTT) and oral glucose tolerance test (OGTT). A rapid glucose disappearance (p < 0.05) with unaltered insulin kinetics during IVGTT and OLTT indicates greater insulin sensitivity in calves supplemented with 0.10 and 0.15 mg of Cr per kg BW0.75. Improved insulin sensitivity in the Cr0.10 and Cr0.15 groups was further confirmed by higher (p < 0.05) values of the insulin sensitivity check index (QUICKI), revised quantitative insulin sensitivity check index (RQUICKI), and lower (p < 0.05) values of the homeostasis model assessment-insulin resistance (HOMA-IR) during IVGTT. Mean serum non-esterified fatty acids (NEFAm), and insulin receptor substrate-1 (IRS-1) levels were the highest (p < 0.05) and cortisol concentrations were the lowest (p < 0.05) in the Cr0.15 groups. Unlike IVGTT, there was no effect of treatment, period, and treatment × period interaction on mean serum glucose and insulin levels during OGTT. However, Cr-supplemented calves had a higher (p < 0.05) glucose clearance rate (gCR). Serum IRS-1 concentrations during OGTT were also higher (p < 0.05) in the Cr0.10 and Cr0.15 groups than in the other groups. Serum Cr levels increased dose dependently and were the highest (p < 0.05) in calves fed a diet supplemented with 0.15 mg Cr per kg BW0.75. There was no effect of treatment on average daily gain (ADG) and body condition score (BCS) while frequency and duration of diarrhea were lower and fecal score was better in Cr-supplemented calves. The current findings show that Cr supplementation improved glucose utilization and health status in calves during their transition period by improving insulin sensitivity.