Impact of adding dietary different levels of protected methionine on wool characteristics, ultrastructure, and blood components of Barki sheep

Twenty-five non-pregnant adult Barki ewes were used to investigate the effect of the addition of various levels of rumen-protected methionine as a feed additive on some wool characteristics, blood components, and wool ultrastructure. Animals were divided according to live body weight and wool measurements into 5 groups. The control group (G1) was fed a basal diet without any supplementations, while G2, G3, G4, and G5 were fed the basal diet supplemented with 6, 9, 12, and 15 g methionine /head/day, respectively, for six months. Wool samples were collected at the end of the experiment to record some wool measurements, such as fiber diameter, staple length, staple strength, elongation, point of break, and clean wool yield. Blood samples were collected to determine some blood biochemicals. Results showed that adding rumen-protected methionine for six months significantly enhanced the wool characteristics of Barki ewes, such as staple length, staple strength, elongation, point of break, fiber diameter, and clean wool yield. Supplementing dietary methionine affected coarse fiber wool scale properties of Barki ewes. The minimum value of scale width was recorded in G2, while the maximum value of scale width was recorded in G5. Also, G2 showed the highest value of scale distance to the edge. Wool of G4 recorded the lowest value of coarse fiber diameter. Methionine supplementation resulted in a slight effect on the values of some blood biochemical parameters. The a propriate dietary methionine supplementation was 12 g /head/day.