Dry residue of cassava on slow-growing broiler diets, with or without the addition of carbohydrases.

Dry residue of cassava was studied on the digestibility, performance, intestinal measurements, with or without inclusion of carbohydrases, of slow-growing broilers. 160 Label Rouge broiler chickens, 21-d-old, were distributed in a randomized, 2x5 factorial arrangement (male and female x 0, 10, 20, 30 and 40% residue) (metabolism trial). 1,100 male chicks were distributed in a 2x5 factorial arrangement (with/without carbohydrases x 0; 2.5; 5.0; 7.5; and 10.0% residue), with five replicates (performance trial). Increasing residue levels led to increases in energetic values. Feed intake from 1-21-d-old and 1-63-d-old decreased linearly. At 42 d-old, feed intake and weight gain levels exhibited a quadratic response, which predicted a highest value at 3.32% and 4.77%, respectively, for diets without carbohydrases. For 21- and 42-d-old chickens, the inclusion of carbohydrases reduced the weight and length of the small intestine. The energetic values of the diets were positively influenced by the residue and had similar digestibility values for both sexes. Inclusion of up to 10% of residue in slow-growing broiler diets does not impaired performance and intestinal morphology. The addition of carbohydrases reduced the viscosity of the digesta but it was not enough to improve the performance of the birds.

Influence of Enzyme Supplementation in the Diets of Broiler Chickens Formulated with Different Corn Hybrids Dried at Various Temperatures.

We evaluated the influence of enzymatic supplementation on the growth performance and cecal microbiota of broilers. A total of 2160 1-day-old male chicks were used in a 3 × 2 × 2 factorial arrangement (three corn hybrids, two drying temperatures -80 and 110 °C, with or without the inclusion of an enzymatic blend (amylase, xylanase, and protease) (20 birds/pen, n = 9). For all performance and digestibility parameters, we observed, in general, isolated effects of the corn hybrids and drying temperature. Birds that received the enzymatic blend in the diet showed better weight gain from 1 to 21 days (d) and better digestibility coefficients of nutrients at 42 d. Birds fed diets with corn dried at 80 °C showed a better feed conversion ratio from 1 to 42 d. At 21 d of age, enzymatic supplementation had positive effects on jejunum morphology. Enzyme supplementation increased the abundance of the phylum Tenericutes, class Bacilli and Mollicutes, reduced Clostridia, and increased the abundances of the families Lactobacillaceae, Anaeroplasmataceae, and O_RF39;F. In conclusion, the addition of amylase, xylanase, and protease led to a better nutrient digestibility, performance, and intestinal morphology. In addition, enzyme supplementation changed the diversity, composition, and predicted function of the cecal microbiota at d 21.