The Effects of Ascorbic Acid and Seasonal Temperatures on Meat Quality Characteristics of Broiler Chickens Maintained in Open-Sided and Closed Houses

摘要

High ambient temperature is one of the prominent stressors that elicits low meat quality characteristics in broiler meat. The effect of ascorbic acid supplementation in drinking water on meat quality of broiler chickens reared in closed and open-sided houses during hot (ambient temperature 36oC) and cool (ambient temperature 23oC) seasons were studied. Four hundred and thirty two, one-day-old chicks were used for each house across the two seasons. Birds were maintained in 23 h light and 1 h dark cycles and offered ad libitum access to water and commercial broiler diets. Broilers in both houses were randomly subjected to four drinking water treatments (9 birds in each 6 replicates/treatment): 0, 100, 200 and 300 ppm ascorbic acid . Pectoralis muscles were taken at 24 h postmortem and analyzed for ultimate pH, expressed juice, cooking loss, Warner-Bratzler shear force value, myofibril fragmentation index, sarcomere length and colour. Pectoralis muscles collected during the hot season had significantly (0.05) higher pH, lower expressed juice, darker colour meat (L*) than those collected during cool season group. During the hot season, meat samples from chicken reared in an open-sided house had significantly (0.0) higher pH and lower lightness value (L*) than those reared in a closed house. Supplementation of drinking water with various levels of ppm ascorbic acid did not significantly improve meat quality characteristics of broiler chicken reared in open-sided or closed housing at high ambient temperatures.