Occurrence and severity of white striping in broilers until 50d of age fed with high and low-energy diets : body weight, histopathological changes and meat quality

White striping (WS) is a condition characterized by the occurrence of white striations parallel to the muscle fibers on breast, thigh, and tender muscle of broilers. This study was aimed to evaluate the occurrence and severity of white striping and histopathological changes in breast fillets from 10 to 50 d broilers disregarding the effect of diet. Birds (n=572) were randomly assigned to a high- (HED) or low-energy (LED) diet (11 replicates of 26 birds/ dietary treatment) and were processed at 10, 20, 30, 40 and 50 d of age to evaluate occurrence of white striping, BW, histological analysis, and meat quality. The results showed that at 10 d of age, 2.27% of the birds showed some degree of WS and at 20 and 30 d of age the occurrence of WS (%) was higher in birds fed HED than birds fed LED diets. There was no differences (P>0.05) in the L*, a*, and b* values for meat or among different degrees of WS as well as between dietary treatments; however, carcass characteristics varied by age or carcass weight. Histologically, the severity of WS causes changes in myofibers, with muscle fibers showing sarcoplasmic reticulum vacuolization, a higher intercapillary distance and a reduced capillary to fiber ratio, suggesting loss of integrity of the cell structure, that was seen in birds fed both diets (low and high nutrient densities) after 30 d of age and lower oxygenation