One-day-old Starbro male broiler chicks (n = 360) were used to determine the effect of increasing levels of Na+ and Cl- above the NRC (1994) recommendations for growing broilers diets (hatching to 28 d) in extremely hot weather. The average maximum and minimum temperatures recorded were 39 and 32 degrees C, respectively. An average relative humidity was 58.2% during the experimental period. Three levels of dietary Na+ (0.20, 0.25, and 0.30%) and Cl- (0.30, 0.40, and 0.50%) were used in 3 x 3 factorial arrangement while maintaining a dietary electrolyte balance (DEB) of 250 mEq/kg. Higher weight gain (P < 0.002) and maximum water consumption (P < 0.05) were observed for birds fed diets containing 0.25 and 0.30% Na+, respectively. Litter moisture was significantly higher (P < 0.05) for birds fed diets containing 0.25% Na+ and 0.40 and 0.50% Cl-. High dietary Na+ (0.30%) tended to increase breast yield (P < 0.003) and decreased abdominal fat (P < 0.001). There was no effect of Na+ on blood pH or serum HCO3-. Diets containing 0.40% Cl- increased the dressing percentage (P < 0.001) and leg yield (P < 0.001) and decreased serum HCO3- (P < 0.001). There was no effect of dietary Cl- on blood pH, feed intake, weight gain, feed:gain, water intake, water:feed intake, or mortality. Significant dietary effect of Na+ x Cl- was noted only for litter moisture (P < 0.001), dressing percentage (P < 0.05), breast (P < 0.05) and leg (P < 0.001) yields, abdominal fat (P < 0.002), and serum HCO3- (P < 0.001). Birds fed diet containing 0.25% Na+ and 0.30% Cl- performed as well as those fed other diets when the cyclic temperature ranged from 32 to 39 degrees C.

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A broiler growth assay was conducted to compare the efficacy of l-lysine HCl and l-lysine sulfate at a graded addition of canola meal (CM). A total of 1,440 1-d-old female Hubbard broiler chicks were allotted randomly to 6 dietary treatments each in 4 replicates of 60 birds per pen. The 2 lysine sources (l-lysine HCl and l-lysine sulfate) and the 3 CM levels (10, 15, and 20%) were used in 2 x 3 factorial arrangement in isonitrogenous (19% CP) and equicaloric (2,700 kcal of ME/kg) diets containing 0.96% digestible lysine. The experiment lasted for 42 d, and a single mash diet was used throughout the experiment. The feed intake during the starter phase (1 to 28 d) decreased linearly as the dietary CM level increased with diets containing l-lysine HCl, whereas feed intake increased linearly with increasing dietary CM level with that of lysine sulfate. Gizzard weight as percentage of carcass weight increased linearly (P < or = 0.016) as dietary CM level increased. No significant effect of lysine sources or CM was observed on body weight gain, feed:gain, mortality, carcass weight, breast and thigh yield, and abdominal fat. In conclusion, l-lysine HCl can be replaced with l-lysine sulfate for broiler diets, and CM can be used as up to 20% of the starter (1 to 28 d) and finisher (29 to 42 d) diets without having any adverse effects of broiler performance.

The response of broiler chickens to 2 levels of endo-1,4-beta xylanase and endo-1,3-beta glucanase combination (with and without), 3 levels of digestible Lys (0.8, 0.9, and 1.0%), and 2 levels of canola meal (CM; 20 and 30%) were evaluated in 2 x 3 x 2 factorial arrangement. A total of 2,448 male Hubbard broiler chicks were fed on practical mash diets having 2,750 kcal of ME.kg(-1) and 19.6% CP from 1 to 42 d of age. The BW gain was significantly reduced when 30% CM was added in the diets during 1 to 21 d. Feed:gain and mortality were also observed to be high. No significant effect of enzyme addition or Lys level was observed on feed intake, BW gain, feed:gain, and mortality during the starter phase. When the data were pooled for 42 d, BW gain and feed:gain were unaffected by enzyme addition or Lys levels. A depression in breast weight was observed due to 30% CM or 0.8 and 0.9% digestible Lys at 43 d. Leg weights were significantly depressed by enzyme addition or increasing digestible Lys to 1.0% of the diets. The AME, nitrogen digestibility, and antibody titers against Newcastle and infectious bursal diseases were also unaffected by the dietary treatments. In conclusion, the 30% CM is not recommended in broiler diets especially during starter phase (1 to 21 d). However, the CM may be used up to 30% of the diets during finishing phase. The digestible Lys can be lowered to 0.8% when amino acids in proportion to digestible Lys follow the ideal AA ratio. The glucanase and xylanase cocktail have no pronounced effect on the growth performance, nutrient digestibility, and carcass characteristics.