Scientific Papers Animal Science and Biotechnologies (Sep 2023)
Quality of the Effect of Chelated Chromium on Selected Serum/Plasma Metabolites in Dairy Cattle
Abstract
The impact of supplementing chelated chromium (Cr) in transition cows has increased recently. The objective of this study was to conduct a systematic review of randomized controlled trials to evaluate the effectiveness of supplementation of chelated chromium (Cr) on plasma glucose, non-esterified fatty acid (NEFA) and insulin during the transition period in dairy cows. A total of 322 transition dairy cows, belonged to seven studies from five papers, were used. The complete steps of meta-analysis were performed according to the standard pathway of PRISMA. For this reason, a comprehensive meta-analysis was used to accomplish this mission. The effect model and I2 statistic was used to estimate the degree of heterogeneity. Forest plot was used to present a graphic means and their confidence intervals, and a heterogeneous degree was explored with meta-regression, also Beggꞌs test was conducted to investigate the publication bias. Estimated the effect size of chelated Cr on glucose, NEFA, and insulin outcomes during the threetime points (i.e. before, at, after calving) was no significant (glucose ES=(0.049-0.078) 0.015, p-value=0.649; NEFA ES=(-0.719-0.45) -0.134, p-value=0.653; and insulin ES=(-0.090-0.154) 0.032, p-value=0.611. The heterogeneity was not significant for all variables (glucose I2=0, p-value=0.981; NEFA I2=0 p-value=1; and insulin I2=0, pvalue=0.980). Consequently, fixed-effects models were used for the analysis of such data. Furthermore, Beggꞌs test indicated no evidence of substantial publication bias for all parameters. The influence analysis showed that the removal of any study did not change the direction or significance of point estimates. The meta-analysis of our study indicated that chelated Cr supplementation of diets of dairy cows during the transition period provided a glucose tolerance effect by increasing the insulin response and decrease NEFA concentration, but not in a significant level.
