Supplemental GAA and arginine-deficient diets
The present experiment was designed to examine arginine (Arg)-sparing effects of guanidinoacetic acid (GAA) on production performance, intestinal morphology and certain blood parameters in broiler chickens. A total of 300 male broiler chicks (Ross 308) were randomly allotted to 5 dietary treatments in a completely randomised design during 1-15 and 15-35 d rearing periods. Experimental treatments consisted of a basal diet with a reduction in Arg content (CON-; starter: 12.1 g/kg and grower: 11.3 g/kg Arg), a CON- diet supplemented with synthetic Arg equal to the required Arg level (CON+; starter: 13.80 g/kg; grower: 12.37 g/kg) and CON- diet supplemented with three levels of GAA (GAA0.6; GAA1.2; and GAA1.8; g/kg). Supplemental GAA at 0.6 and 1.2 g/kg reduced the adverse effects of the CON- diet on weight gain and feed conversion ratio in the starter period, equal to the effect of CON+ diet. During the entire rearing period, such an effect was only seen for broilers fed CON- diet supplemented with 1.2 and 1.8 g/kg GAA (P < 0.05). Proportional weights of liver and abdominal fat were decreased in birds fed diets containing supplemental Arg and 1.8 g/kg GAA compared to the CON- broilers (P < 0.05). Jejunal villus height and villus height to crypt depth ratio were increased in broilers receiving the CON- diet (P < 0.05). Serum concentration of nitric oxide increased when the CON- diet was supplemented with either Arg or 1.8 g/kg GAA (P < 0.05). Dietary inclusion of GAA had an Arg-sparing effect, whereby 1.2 and 1.8 g/kg of supplemental GAA resulted in greater growth performance during the starter and entire rearing periods, respectively. Supplementation with 1.8 g/kg GAA had significant effects on some carcass and physiological parameters.
Ale Saheb Fosoul SS, Azarfar A, Gheisari A, Khosravinia H. Performance and physiological responses of broiler chickens to supplemental guanidinoacetic acid in arginine-deficient diets. Br Poult Sci. 2019;60(2):161-168. doi:10.1080/00071668.2018.1562156