The effect of maternal or artificial milk, age and sex on three muscles fatty acid profile of Damascus breed goat kids

Abstract

Meat quality is related to a variety of muscle types consisting of different muscle fibers which are a reflection of its energy requirements and lipid content. Due to that, factors such as source of suckled milk, age and sex which affect the fatty acid (FA) profile and associated with meat quality should be determined in different muscles, since humans consume different parts of the carcass. A total of 40 goat kids of Damascus breed were used to determine the effect of rearing system, age and sex on the FA profile of Semimembranosus proprius (SP), Longissimus dorsii (LD) and Triceps brachii (TB). The goat kids were assigned into two groups balanced for body weight and sex. The first group (n=20), (10 male and 10 female goat kids) underwent natural rearing and received only maternal milk until weaning. The second group (n=20) (10 male and 10 female goat kids), was subject to artificial suckling with a commercial milk replacer. At weaning (49 days of age), 10 animals from each group were weighed and slaughtered. The remaining goat kids of both groups, after weaning were fed daily 100g barley hay per animal and a commercial concentrate diet ad libitum up to 98 days of age, where they were also weighted and slaughtered. The results showed that the body weight and the growth rate were significantly higher in males than females goat kids when fed with maternal milk. Moreover, the growth rate was significantly higher in the naturally compared with the artificially goat kids. The muscles FA composition, especially the branched chain FA, saturated FA and n-3 FA, reflects that of the milk source (maternal or artificial). Significant differences were found among the three muscles (SP, LD and TB) of goat kids for several individual FAs. The concentrations of C18:0 and trans C18:1 FA increased significantly whereas n-3 FAs decrease in the fat of goat kids slaughtered at 98 compared 49 days of age, due to the shift from milk to a fodder diet. Sex did not affect the FA profile of goat kids. In conclusion, naturally reared goat kids is better slaughtered at younger age before a shift from milk to a fodder diet whereas a fodder diet compared with a milk replacer can improve muscle FA profile of goat kids.