Attenuating susceptibility to ascites in cold-stressed broiler chickens fed canola meal-based diets by supplementing arginine or guanidinoacetic acid, either alone or in combination with phenylalanine.

OBJECTIVE: The purpose of this study was to determine the effects of dietary supplementation of arginine (ARG) or guanidinoacetic acid (GAA), with or without phenylalanine (PHE), on the ascites susceptibility in the cold-stressed broilers fed canola meal (CM)-based diet. METHOD: A total of 450 one-day-old male broiler chicks were randomly allocated to 30 floor pens with 6 replications for each of the 5 treatments. The dietary treatments were as follows: CM-based diet (control), CM-based diet + 2.57 g/kg ARG, CM-based diet + 1.8 g/kg GAA, CM-based diet + 2.57 g/kg ARG + 1.5 g/kg PHE and CM-based diet + 1.8 g/kg GAA + 1.5 g/kg PHE. The groups experienced cold stress induction starting at 32°C on day one, with gradual reductions to 15°C on days 21. The temperature was then held at 15°C for the remainder of the experiment. RESULTS: The supplements ARG + PHE and GAA + PHE resulted in improved feed conversion ratios (FCR) when compared to the control group. In comparison with the control group, supplementation of ARG and ARG + PHE decreased the ascites mortality by increasing the plasma nitric oxide level (NO), blood O2 partial pressure, blood O2 saturation (SO2), and decreasing the blood CO2 partial pressure (PCO2) and right ventricle to total ventricle (RV:TV) ratio. Supplementation of GAA and GAA + PHE also declined ascites mortality by reducing blood PCO2 while increasing blood SO2 and plasma NO levels. Although plasma corticosterone level and RV:TV ratio were similar between the GAA and control groups, adding GAA + PHE significantly reduced both compared to the control group. CONCLUSION: In summary, supplementing cold-stressed broiler chicken diets with 2.57 g/kg ARG may alleviate hypertension. Additionally, 1.8 g/kg GAA proves to be an effective substitute for dietary ARG in low-ARG diets, alleviating adverse effects from cold stress. Proper PHE formulation, at 1.5 g/kg in this study, is crucial when using ARG and GAA supplements.

Effects of arginine and guanidinoacetic acid with or without phenylalanine on ascites susceptibility in cold-stressed broilers fed canola meal-based diet.

In order to evaluate the effects of ARG sources (arginine [ARG] and Guanidinoacetic acid [GAA]) and phenylalanine (PHE) supplementation on performance, susceptibility to ascites, intestinal morphology, and nutrient digestibility in the cold-stressed broilers fed a canola meal (CM)-based diet, a 2×2 factorial experiment with four treatments was conducted. The dietary treatments included CM-based diet + 2.57 g/kg ARG, CM-based diet + 2.57 g/kg ARG + 1.5 g/kg PHE, CM-based diet + 1.8 g/kg GAA and CM-based diet + 1.8 g/kg GAA + 1.5 g/kg PHE. The corn-CM diet without supplementation was used as a negative control (NC) group in the fifth treatment that excluded the factorial arrangement. The results showed that adding ARG to diets without PHE supplement increased (p < 0.05) feed intake. Also, birds fed diets containing ARG had higher (p < 0.05) body weight gain (BWG) compared to those fed GAA added diets. Supplementation of PHE improved (p < 0.05) the FCR compared to groups fed diets without added PHE. Further, ARG addition increased (p < 0.05) plasma nitric oxide (NO) concentration, carcass, breast and leg yields, duodenal, jejunal, and ileal villus height (VH) to crypt depth (CD, and dry matter digestibility, while decreasing (p < 0.05) ascites mortality and right ventricle (RV) to total ventricle (TV) ratio compared to GAA added groups. Supplementation of PHE also declined susceptibility to ascites by reducing (p < 0.01) RV to TV ratio while increasing (p < 0.05) plasma NO level. The digestibility of ether extract also increased (p < 0.05) in broilers fed GAA supplemented diets versus those fed ARG added diets. The findings suggested that ARG may improve BWG and lower ascites incidence in broilers fed a diet based on CM under cold stress because of its antihypertensive effects. Moreover, the findings of this study demonstrated the importance of including PHE formulation in ARG-deficient diets to attenuate the adverse effects of cold stress on broilers. It was also concluded that GAA could be efficaciously used in cold-stressed broilers fed an ARG-deficient diet.