Relationship between rearing practices and eating quality traits of the muscle rectus abdominis of Charolais heifers

Abstract : Ninety-nine Charolais heifers with an average age of 3 3 months and an average carcass weight of 3 81 kg were used to study the relationship between rearing practices and eating meat quality traits. Farm surveys were carried out to collect information about heifer rearing before weaning, during the growth period and during the finishing stage. The quality of meat from the M. rectus abdominis excised 24 h post mortem was scored between 0 and 10 by sensory analysis using four descriptors: initial tenderness, overall tenderness (OT), juiciness and flavour intensity. Intramuscular fat content was also measured. Four classes of rearing practices were differentiated by multiple correspondence analysis and hierarchical cluster analysis. The class I was based on a low feeding level during the growth period and a diet of hay and straw complemented with 8 kg of concentrates in the barn during the finishing period. A medium feeding level during the growth period and a finishing diet of grass at pasture and 6 kg of concentrates defined the class 3. The class 2 was linked to a high feeding level during the growth period and a supply of roughage and 6 kg of concentrates at pasture during the finishing stage. The class 4 was based on a high feeding level during the growth period and a finishing stage in the barn with maize silage and 5 kg of concentrates. There were no differences in meat juiciness and meat flavour intensity among the four practice classes. The classes 2 and 4 produced the tenderest meat (OT score: 5.5/10; p = 0.002), regardless of the finishing stage and the forage given to the animals. These classes were characterized by the highest feeding level, which allowed slaughter at a young age (32 months) resulting in the highest carcass weight (380 kg). The classes I and 3 classes were linked to the lowest tenderness (OT score: 4.8;p=0.002) although the intramuscular fat content was equivalent to the classes 2 and 4 (17.8% in average). The classes I and 3 were characterized by a moderate growth period due to a low feeding level and a short finishing stage (108 to 13 5 days). Indeed, the finishing period did not allow the animals to recover the growth deficit brought about by the growth period. This type of farming practice required slaughter at a more advanced age (35.9 months) for equivalent carcass weights of 389 kg.