Effect of Different Levels of Chromium Methionine Supplementation on Growth Performance, Meat Oxidative Stability and Ruminal Metabolites of Male Goat Kids

This study was performed to determine the effects of different levels of chromium methionine (Cr-Met) supplementation on growth performance, meat oxidative stability and ruminal metabolites in male kids. Thirty-two male Mahabadi goat kids, with an average initial body weight (BW) of 22 ± 2 kg at 4 months of age, were allocated in a completely randomized design with four treatments: control without Cr and three levels of Cr supplementation 0.5, 1 and 1.5 mg respectively as Cr-Met/animal/d. Diets were the same for the all groups with a ratio forage: concentrate of 30:70, except for the addition of Cr-Met. The animals were fed in two equal meals (at 08:00 and 16:00 h) and the leavings were collected before the morning meal. Animals were kept in individual pens for 100 days. Kids were weighed after 10 days of adaptation period and at 21 days intervals after feed restriction. Kids were slaughtered at the end of the trial and Longissimus dorsi muscle (LDM) samples were immediately stored at -20 ?C. Thio Barbioturic Acid Reactive Sub-stances (TBARS) methods were used in order to measure meat stability. Supplemental Cr-Met did not af-fect (P > 0.05) the final BW, total BW gain, dry matter intake (DMI) and average daily gain (ADG). Concen-trations of NH3-N and total and individual volatile fatty acids (VFA) in the rumen were not affected by the Cr-Met (P > 0.05). However, Cr-Met supplementation increased rumen pH and decreased ruminal protozoa count (P < 0.05). TBARS values of the LDM were significantly increased as the storage time increased from 1 to 2 months (P < 0.05). It was also found that increasing dietary chromium supplementation, especially at level of 1.5 mg Cr-Met, significantly decreased lipid oxidation and the TBARS value at 2 months of storage (P < 0.05). These results indicate that supplementation of goat kid diet with Cr-Met had minimal effects on growth performance and rumen metabolites but improved oxidative stability of LDM during refrigerated storage kids.