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 temp. has a negative impact on chicken meat quality. This study investigated the effects of ascorbic acid supplementation in drinking water on meat quality of broiler chickens reared in closed and open-sided houses during hot (ambient temperature 36 degrees C) and cool (ambient temp. 23 degrees C) seasons. 432, one-day-old chicks were used for each house across the 2 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 4 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 analysed 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 (P < 0.05) higher pH, lower expressed juice and darker meat (L*) than those collected from the cool season group. During the hot season, meat samples from chickens reared in an open-sided house had significantly (P < 0.0) higher pH and lower lightness values (L*) than meat from chickens reared in a closed house. Supplementation of drinking water with various levels of ascorbic acid did not significantly improve meat quality under any of the above sets of conditions.