Superdose de fitase, diferentes pH de água e dois sistemas de aviários sobre a eficiência produtiva de frangos de corte

Abstract

The objective of this study was to evaluate the effect of high dose of phytase, different pH of water in different housing systems on performance, ileal digestibility, blood parameters, bone quality, intestinal pH and circulating myo-inositol of broilers. A study was carried out at the Federal University of Santa Maria which is described in chapters I and II. In Chapter I: INTERACTIVE EFFECTS OF DRINKING WATER pH, POULTRY HOUSING SYSTEM AND EXOGENOUS MICROBIAL PHYTASE ON GROWTH PERFORMANCE, ILEAL DIGESTIBILITY OF NUTRIENTS, INTESTINAL pH, SKELETAL INTEGRITY AND PLASMA MYO-INOSITOL CONCENTRATIONS IN BROILER CHICKENS, were used 4,000 broilers of the Cobb-500 line distributed in a completely randomized design, with a factorial arrangement 4x2x2, being: 4 diets: diet 1: positive control (CP) without supplementation of phytase, diet 2: negative control [NC - reduction of 0.15% calcium (ca) and 0.15% phosphorus (avP)], diet 3: negative control with supplementation of 1,000 FYT / kg of phytase and diet 4: negative control with supplementation of 2,500 FYT / kg of phytase , two water pH (6.2 and 8.2) and two housing systems (conventional and climate-controlled poultry), totaling 16 treatments, 8 treatments with 7 repetitions with 50 chickens in the climate-controlled and 8 treatments with 6 repetitions with 25 broilers in the conventional house. The pH 6.2 influenced the efficiency of phytase in the initial phase of broilers, pH 8.2 improved the GP, CA in the final phase of creation and increased the pH of gizzard content. The different phytase inclusions improved the apparent ileal digestibility of Ca, P and N. The concentration of myo-inositol in plasma was higher in broilers housed in conventional house supplemented with phytase. The inclusion of 2,500FYT/kg of phytase improved the bone characteristics (ash, Ca and P) of the broilers. In chapter II: EFFECTS OF HOUSING SYSTEMS AND WATER pH ON PERFORMANCE, INTESTINAL pH AND SERUM BIOCHEMICAL PARAMETERS OF BROILERS, 1,000 broilers of the Cobb-500 line were used distributed in a completely randomized design, with a factorial arrangement 2x2, with 2 housing systems (conventional and acclimatized poultry house) and 2 pH of drinking water (6.2 and 8.2), totaling 4 treatments, 2 treatments with 7 repetitions of 50 birds each in the acclimatized poultry house and 2 treatments with 6 repetitions of 25 birds each in the conventional house. To raise the water pH from 6.2 to 8.2, a concentrated sodium bicarbonate solution (NaHCO3) was used. The pH 8.2 improved the performance and serum levels of circulating glucose in broilers housed in conventional house. In conclusion, the use of high dose of phytase can be used in diets with reduced nivel Ca and P without causing damage to the performance of broilers, and improve ileal digestibility, bone quality and circulating myo- inositol, in addition, water pH 8.2 helps to reduce impacts of heat stress in broilers housed in a conventional poultry house.