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.

Copper sulfate and arginine supplements on performance, thyroid hormones and blood biochemistry of broilers fed with canola meal-based diets / Avaliação da suplementação com sulfato de cobre e arginina sobre o desempenho, hormônios tireoidianos e bioquímica sanguínea de frangos alimentados com dietas à base de canola

The present evaluated the effects of copper sulfate solution (CSS) and arginine powder (Arg) supplements on performance, thyroid hormones and blood biochemistry of broiler chickens fed with canola meal (CM)-based diets. The experimental design was completely randomized with a 3 × 3 factorial and 9 treatments, corresponding to 3 levels of CSS (0, 125 and 250 mg/kg) and 3 levels of Arg (0, 0.1 and 0.2%) (n = 45 per treatment). Feeds were offered ad libitum for 21 days, from 22 to 42 days of age. Feed efficiency was significantly affected by the dietary addition of 250 mg/kg CSS and 0.2% Arg, and by the CSS × Arg interaction. CM supplemented with CSS improved the thyroid gland status and increased the plasma levels of triiodothyronine and thyroxine. Birds fed diets supplemented with 0.2% Arg had lower blood glucose level than the other treatments. The addition of 250 mg/kg CSS and 0.2% Arg reduced the stress caused by the rapid growth of broilers, also increasing the overall bird welfare.

O objetivo do presente trabalho foi avaliar os efeitos da suplementação com solução de sulfato de cobre (SSC) e arginina em pó (Arg) sobre o desempenho, hormônios tireoidianos e bioquímica sanguínea de frangos de corte alimentados com dietas à base de canola DC. O desenho experimental foi completamente casualizado com fatorial 3 × 3 e nove tratamentos correspondentes a três níveis de inclusão de SSC (0, 125 e 250 mg/kg) e três níveis de Arg (0, 0,1 e 0,2%) (n = 45 para cada tratamento). As rações foram oferecidas ad libitum por 21 dias, de 22 até 42 dias de idade. A eficiência alimentar foi significativamente afetada pela adição de 250 mg/kg de SSC e 0,2% de Arg, assim como pela interação SSC × Arg. A suplementação da DC com SSC melhorou os parâmetros da glândula tireoide e aumentou os níveis plasmáticos de triiodotironina e tiroxina. As aves alimentadas com dietas suplementadas com 0,2% de Arg apresentaram menor nível de glicose sanguínea do que as dos demais tratamentos. A adição de 250 mg/kg de SSC e 0,2% de Arg reduz o estresse causado pelo rápido crescimento dos frangos, além de melhorar as condições gerais de bem estar das aves.

Evaluation of Different Levels of Canola Meal on Performance, Organ Weights, Hepatic Deiodinase Gene Expression and Thyroid Morphology in Broiler Chickens.

This study was carried out to determine the effects of dietary inclusion level of canola meal (CM) on performance, organ weights and hepatic type I deiodinase gene expression in broilers. A completely randomized design with 4 levels of CM (0, 10, 20 and 30%) as a substitute for soybean meal (SBM) was utilized with 5 replicates of 9 birds each. The results showed that body weight gain (1 to 42 d) decreased linearly (P<0.01) as the inclusion of CM increased. An increase in dietary level of CM also resulted in a linear (P<0.05) increase in feed conversion ratio (1 to 42 d). Proportion of thyroids (P<0.05) and liver (P<0.01) increased linearly with increased levels of CM. A significant linear increase in right ventricular weight: total ventricular weight ratio (P<0.01) and heart weight (P<0.05) were observed by substituting CM for SBM. The concentration of plasma triiodothyronine and triiodothyronine: tetraiodothyronine ratio decreased linearly (P<0.01) with increasing level of CM. Expression of hepatic type I deiodinase gene (D1) decreased linearly (P<0.01) as inclusion level of CM in diets increased. Moreover, increasing linear (P<0.01) and quadratic responses (P<0.05) were observed in follicles number and epithelial thickness in broilers thyroids followed by increased levels of CM. In addition, increases in dietary CM inclusion led to a linear (P<0.01) increase in thyroid follicles diameters. In conclusion, the results of this study indicate that feeding increasing CM inclusions from 0 to 30% negatively affect growth performance of broiler chickens. From this study, it can also be concluded that substitution of CM for SBM adversely interferes with thyroid and liver functions and decrease D1 gene expression, likely because of higher dietary concentration of glucosinolates.