Effects of Supplementary Blood Meal on Carnosine Content in the Breast Meat and Laying Performance of Old Hens (Report‪)‬

INTRODUCTION Carnosine, [beta]-alanyl-L-histidine (L-Car) is dipeptide that was discovered in mammalian skeletal muscle (Boldyrev and Severin, 1990). Carnosine has many beneficial roles as an antioxidant (Bogardus and Boissonneault, 2000; Nagasawa et al., 2001), antiglycation molecule (Hipkiss, 2005; Alhamdani et al., 2007), anti-cross-linker (Hobart et al., 2004) and anti-aging agent (Wang et al., 2000; Hipkiss et al., 2001). Many researches on L-Car has focused on its physiological roles (Boldyrev et al., 1997; Begum et al., 2005) and therapeutic activities (Gariballa and Sinclair, 2000). Although L-Car is biosynthesized endogenously in the animal body, little is known about the nutritional manner of enrichment of L-Car in the animal body. A few papers have reported that the supplementation of L-histidine (L-His) (Amend et al., 1979; Haug et al., 2008) or [beta]-alanine ([beta]-Ala) (Tomonaga et al., 2005) increases L-Car in the chicken muscle. White muscle tissue has a higher L-Car content than red muscle tissue (Plowman and Close, 1988; Boldyrev et al., 2004). Among the white muscle tissue animals, chicken is a representative animal that has high L-Car content (Boldyrev and Severin, 1990). Chicken breast muscle (CBM) has more L-Car content than other parts of the chicken (Intarapichet and Maikhunthod, 2005).