The use of dietary chromium associated with vitamins and minerals (synthetic and natural source) to improve some quality aspects of broiler thigh meat reared under heat stress condition

The effect of chromium associated with vitamins and minerals (synthetic or natural ingredients) on broiler meat nutritional quality, subjected to heat stress conditions were evaluated. The 6-week feeding trial was conducted on 120 unsexed 1-day-old Cobb 500 broilers, assigned to 4 treatments and housed in digestibility cages at 32 °C constant temperature. Compared to the control diet (C), the experimental diets were supplemented with 200 µg/kg diet chromium picolinate (Cr), as follows: Cr-AA has 0.25 g ascorbic acid/kg diet; Cr-Zn has 0.025 g zinc/kg diet; Cr-WS has 10 g creeping wood sorrel/kg diet. The results of the study showed that essential amino acids concentrations determined in the thigh meat samples tend to increase in groups supplemented with chromium and ascorbic acid and chromium and zinc, especially sulphur containing amino acids (methionine and cystine) which increased for experimental groups (methionine: 1.25% (C) vs. 1.77% (Cr-AA); 1.58% (Cr-Zn); 1.64% (Cr-WS) and cystine: 0.46% (C) vs. 0.52% (Cr-AA); 0.54% (Cr-WS)). Among the compounds with biological value, vitamin E and lutein & zeaxanthin concentration registered the highest increase for chromium and zinc supplemented group (vitamin E: 35.49 mg/kg (C) vs. 59.05 mg/kg (Cr-Zn) and lutein & zeaxanthin: 0.66 mg/kg (C) vs. 1.36 mg/kg (Cr-Zn)). The peroxidation process was delayed under nutritional supplements influence, the primary oxidation parameters (peroxide value) from the Cr-WS group being significantly lower compared to the control group. The same trend was maintained for the secondary oxidation parameters, the Cr-WS group highlighting reduced values for p-anisidine and TBARS concentration compared to the C group (p-anisidine: 17.22 (C) vs. 9.29 (Cr-WS) and TBARS: 0.15 mg/kg (C) vs. 0.11 mg/kg (Cr-WS)). In conclusion, sulphur-containing amino acids (methionine and cysteine) concentrations increased for experimental groups, in the thigh meat samples, the liposoluble compounds (vitamin E, lutein & zeaxanthin) concentration registered the highest increase for chromium and zinc supplemented group and the peroxidation process was more pronounced delayed under chromium and wooden sorrel combination.