Superdosagens de fitase combinada com a vitamina D em rações para frango de corte

Abstract

The objective of this study was to evaluate the superdoses of phytase combined with semiactive Vitamin D (hydroxy-cholecalciferol), on bone mineralization characteristics, carcass yeld and performance of broilers.The experiment was conducted out in a conventional shed in the floor system, with tubular feeders and nipple drinker lasting 42 days. A total of 2,160 oneday-old male ROSS chicks (AP 308) were distributed in randomized design (RD), 72 experimental plots where they received eight treatments with nine replications of 30 birds each. The treatments were: T1 - positive control meeting the nutritional requirements (ROSTAGNO et al., 2017), T2 - negative control reducing 0.15% Pd and 0.19% Ca, (the other treatments also had reduced levels of Ca and Pd), T3, T4 and T5 - had Phytase addition (1000 FYT / Kg, 2500FYT / Kg and 4000 FYT / Kg, respectively) and T6, T7 and T8 - in addition to Phytase was added semi-active Vitamin D (1000 FYT / Kg and 69 ppb Vitamin, 2500 FYT / Kg and 69 ppb Vitamin and 4000 FYT / Kg and 69 ppb Vitamin, respectively).Feed and water were providedad libitum. Performance was analyzed by feed intake (CR), weight gain (GP) and feed conversion (CA) at 21 and 42 days. At 21 days five birds were slaughtered and at 42 days 3 birds per parcel (mean weight ± 5%) to be made the carcass yield and evaluation of percentages of ashes, CA and P, Seedor index and bone rupture strength tibias. Data were submitted to ANOVA and when significant TUKEY test was applied for performance characteristics and SNK for bone quality characteristics with 5% significance, analyzed using the SAS 9 statistical program. Evaluating performance from 1 to 21 and 1 to 42 days only the negative control was worse (P <0.05) for GP and CR characteristics. There was no difference (P <0.05) in carcass, breast, thigh, over-thigh and wing yields. In the bone quality assessment from 1 to 21 days, the negative control was worse among the others (P <0.05). In evaluations from 1 to 42 days the% ash of T8 was superior (P <0.05) to the negative treatment and T3 and for% Ca,% P, bone rupture resistance and seeder index again the negative control was inferior to the others. (P <0.05). Using treatments without addition of vitamin D (T2, T3, T4 and T5) a linear regression can be done showing the increase of the Phytase enzyme for GP from 1 to 21 days and from 1 to 42 days. There was no significant difference regarding the addition of vitamin D in any performance characteristics, however, using 2,500 FYT / kg of Phytase in the period from 1 to 42 days obtained an increase in weight gain.evidence that using 1000 FYU / Kg of Phytase with additives from Vitamin D to be used to recovery and quality the bones of birds, the Vitamin D and a Phytasenot improve carcass and parts yield.