Effects of incremental dietary chromium (Cr³⁺) on growth, hormone concentrations and glucose clearance in growing goats (Capra hircus)

Abstract

Castrated male black Bengal kids were supplemented daily with 0, 0·5, 1·0, 1·5 and 2·0 mg chromium (Cr3+ as chromic chloride hexahydrate) for 150 days. Metabolic stresses such as a feeding challenge, an intravenous glucose tolerance test (IVGTT) and a short-term (72 h) feed deprivation were imposed on the animals to ascertain if supplemental Cr could alleviate these stresses and whether the stress-alleviating effect could provide an explanatory basis for the performance traits of the supplemented animals. The kids were fed with a concentrate diet containing 0·197 mg Cr/kg DM. DM intake (g/kgw0·75) was lower (P=0·006) in the 0·5 and 1·5 mg groups. Feed efficiency tended (P=0·086) to improve in the Cr-supplemented kids, although a distinct dose response was absent. Basal serum T3 increased linearly (P=0·01) with increased dose of Cr although the post-prandial change did not follow any definite trend. Basal serum insulin increased (P=0·001) linearly while the post-prandial increment was higher (P=0·037) in the control group. The IVGTT indicated that the kids supplemented with 1·5 mg Cr had significantly (P<0·05) higher serum clearance rate and lower half-life for insulin. Serum Cr during the IVGTT declined (P<0·05) until 45 m after glucose infusion and then increased again (P<0·10) at 60 m in the 0·5 and 1·5 mg groups although in the rest of the experimental groups serum Cr was stable during the entire course of the IVGTT. The body weights at the beginning of the fast were higher (P=0·036) in the kids supplemented with 0·5 and 1·5 mg Cr. However, the change in body weight at the end of the 72 h fast did not vary (P>0·10) between the groups. Cr supplementation reduced (P<0·05) serum cortisol level in the supplemented animals consistently throughout the duration of the feed deprivation. Moreover, as the fast progressed serum cortisol tended to increase (P=0·059) in all the experimental groups irrespective of the level of Cr supplementation. It was concluded that inorganic Cr supplementation might appreciably increase serum T3 concentration and reduce the level of cortisol which might augment animal productivity. However, further research with a more sensitive design is required to establish the exact level of Cr supplementation for enhancing performance of livestock.

Effects of dietary chromium supplementation on glucose tolerance and primary antibody response against peste des petits ruminants in dwarf Bengal goats (Capra hircus)

“…However, the 1Cr group of goats had a higher growth rate and better FCR compared to the control group of goats despite the absence of any stress per se. This corroborated our earlier findings (Paul et al, 2005;Haldar et al, 2006) and reiterated the beneficial effects of Cr in non-stressed goats. Nevertheless, the performance data with the presently employed small experimental population should be cautiously interpreted considering the slower growth rate and the late stage of maturity.…”

“…The effects of supplemental Cr on peripheral neutrophil phagocytic activity and other parameters related to innate immunity are yet to be confirmed, although the in vitro stimulation of blastogenic responses of peripheral blood lymphocytes due to Cr is encouraging (Borgs and Mallard, 1998). Supplemental Cr reduced circulatory cortisol, corroborating earlier findings (Chang and Mowat, 1992;Moonsie-Shageer and Mowat, 1993;Mowat et al, 1993;Haldar et al, 2006 and, and this might have had an impact on the enhanced immune response, albeit transient, in the 1Cr group of goats as reported earlier with other livestock species (Borgs and Mallard, 1998). Chromium supplementation resulted in a sustainable elevation in circulatory insulin in the 1Cr group of goats despite a blunted response to the insulinotropic effect of glucose during the IVGTT.…”

“…Inorganic Cr salts like chromic chloride (CrCl 3 ) are relatively less available for absorption (Mordenti et al, 1997) and hence are of little biological significance. However, some recent publications indicate that supplementation of CrCl 3 may also improve growth and productive performance in non-stressed goats (Paul et al, 2005;Haldar et al, 2006), dairy heifers (Biswas et al, 2006) and broiler chickens (Ahmed et al, 2005). Additionally, little difference in glucose tolerance was observed when goats were supplemented with CrCl 3 or Cr-yeast complex (Haldar et al, 2007).…”

Glucose tolerance and serum concentrations of hormones and metabolites in goats (Capra hircus) fed diets supplemented with inorganic and organic chromium salts

“…In an earlier study with the same animal model Haldar et al (2006) reported that the clearance rate (k) of both glucose and insulin increased and their T 1/2 decreased due to Cr (as Cr chloride) supplementation. However, in the present investigation, the k and T 1/2 of insulin remained unaffected though those of glucose improved indicating an enhancement in glucose tolerance (ability of a subject to maintain blood glucose level closer to the basal value after an oral or intravenous loading of glucose (Kaneko et al, 1997)).…”

“…Perhaps it would be inappropriate to correlate the concentration of the N metabolites in serum with the status of protein metabolism in the experimental goats since the former may lack adequate sensitivity required to predict subtle changes in protein metabolism that may arise as a result of Cr supplementation. The role of supplemental Cr in reducing circulatory cortisol level in ruminants is well established (Chang and Mowat, 1992;Moonsie-Shageer and Mowat, 1993;Mowat et al, 1993;Haldar et al, 2006). Most of the findings depicting a reduction in the circulatory cortisol level due to Cr supplementation involved one or more stress factors like transportation or vaccination.…”