Meat quality of heat stress exposed broilers and effect of protein and vitamin E.

1. This study was designed to determine the effects of heat stress exposure on broiler fattening performance, meat quality and microbial counts. 2. Six groups were established: CHP (24°C+210 g/kg crude protein (CP)), SHP (34°C+210 g/kg CP), CLP (24°C+190 g/kg CP), SLP (34°C+190 g/kg CP), SHPVE (34°C+210 g/kg CP+Vitamin E) and SLPVE (34°C+190 g/kg CP+Vitamin E) groups. 3. It was determined that the body weights of the male animals included in Group CHP displayed statistically significant differences in comparison to those of Groups SHP, CLP and SLP. Furthermore, it was ascertained that the values of Group CLP also displayed statistically significant differences in comparison to those of Groups CHP, SHP and SLP. The feed consumptions in Groups CHP and CLP were significantly different from those of the remaining groups, excluding Group SHP. The highest feed conversion rate was determined in Group SHPVE. 4. When evaluated for chicken drumstick TBA values, Group CHP differed significantly from Groups SHP, SHPVE, CLP and SLP, whilst Group CLP differed significantly from Groups SHP, SHPVE and SLP. On the other hand, when evaluated for breast meat TBA values, Group CHP displayed statistically significant differences in comparison to Groups SHP, SLP and SLPVE, whilst Group CLP differed significantly from Groups CHP, SHP, SLP and SLPVE. 5. The sensitivity of breast meat to colour susceptibility was greater than that of chicken drumsticks. While storage period affected the TBA values and microbial counts of meat significantly, its effect on colour parameters was found to be variable. Trial groups significantly affected total aerobic mesophilic bacteria counts in chicken drumsticks, and Enterobacteriaceae and total aerobic mesophilic bacteria counts in breast meat. 6. In conclusion, heat stress adversely affected final body weights and the lipid oxidation of meat, whilst vitamin E alleviated these adverse effects.

Effects of ascorbic acid and α-lipoic acid on performance and meat quality of broilers subjected to heat stress.

1. The present study was aimed to investigate the effect of adding ascorbic acid or α-lipoic acid to to the diet of broilers exposed to heat stress on performance and meat quality. 2. Heat stress caused a decrease in final body weight and feed consumption, whilst ascorbic acid (AA) and α-lipoic acid (ALA) partly prevented the decrease in final body weight of males. 3. While heat stress increased the pH values of broiler drumsticks and breast meat, AA and ALA partly reduced this increase. For meat quality, AA and ALA reduced the adverse effects on the relative yellowness value, particularly on d 14 of storage. 4. It was determined that heat stress affected the microbiological quality of meat adversely, and that AA and ALA alleviated this effect to a certain extent. 5. In conclusion, while heat stress affected body weight gain and meat quality adversely, the supplementation of the ration with AA and ALA partly alleviated these adverse effects.

Effects of α-lipoic acid, vitamins E and C upon the heat stress in Japanese quails.

Antioxidant vitamins are commonly used as colorant, preventive, sweetener, nutritive and antioxidant materials in food industry. Thus, many studies have been conducted in recent years. We have performed the present study to understand the effects of α-lipoic acid (ALA), vitamin C and E, added into rations of Japanese quails, on chronic heat stress. This study was carried out in five groups as: control, stress, ALA, vitamin E and vitamin C groups. Heat stress is applied to all groups except the control group. Superficial pectoral muscles tissues were used for biochemical determinations. During the research, it is found that heat stress exerted undesired effects such as increasing lipid peroxidation (LPO) level indicating oxidative stress in Japanese quails. In addition, superoxide dismutase (SOD) and catalase (CAT) enzyme activities and glutathione (GSH) amounts were studied to understand the behaviour of defence mechanism. While stress increased LPO ratio, it was determined that all antioxidant added into the ration decreases LPO significantly (p < 0.05). In addition, it was determined that all of antioxidants added into ration effectively restored SOD activity and LPO ratio which heat stress affected negatively. Interestingly, vitamin C did not adjust GSH ratio in contrast to vitamin E and ALA, where vitamin E and C did not perform any positive effect on heat stress decreased CAT activity. Finally, it can be thought that antioxidant vitamins relatively ameliorated these undesired affects caused by stress factors given.