High doses of phytase on growth performance, bone mineralization, diet utilization, and plasmatic myo-inositol of turkey poults

Abstract

An experiment was conducted to evaluate the growth performance, bone mineral composition, diet utilization, and plasmatic concentration of myo -inositol ( MYO ) in turkeys fed different phytase doses from 1 to 28 d. A total of three hundred and twenty 1-day-old turkeys were distributed in a completely randomized design with 4 treatments and 8 replicates of 10 birds each. Treatments included a basal diet without phytase; reduced diet (reduced −0.15% available P and −0.18% Ca) without phytase; reduced diet + 2,000 units of phytase ( FYT )/kg; and reduced diet + 4,000 FYT/kg. From day 26 to 28, partial excreta collection was conducted, and on day 28, 7 birds per replicate were euthanized for collection of ileal content and left tibia bones were removed from 2 of the same euthanized birds. Feed, excreta, and ileal digesta samples were analyzed to determine nutrient digestibility and metabolizability, ileal digestible energy, and AME. Tibia bones were analyzed for ash, Ca, and P content, and calculation of Seedor index. On day 28, blood samples were collected from 2 turkeys per replicate to analyze plasmatic MYO concentration. Feed conversion ratio was not affected, but phytase supplementation resulted in higher feed intake and body weight gain compared to turkeys fed the reduced diet ( P < 0.05), and both doses were similar to the basal diet. Increasing the phytase dose had a linear effect ( P < 0.05) on ileal digestibility of P and metabolizability of DM, CP, Ca, and Na, and also on AME. P content in the tibia bone increased linearly ( P < 0.05) with phytase supplementation, and the same linear increase ( P < 0.05) was observed for plasmatic MYO. In conclusion, the supplementation of turkey poult's diets with high levels of phytase up to 4,000 FYT/kg improves diet utilization by increasing P digestibility and dietary metabolizability, leading to higher P content in the bone and enhancing MYO provision and absorption.

Dietary phytase effects on copper requirements of broilers

“…The addition of exogenous phytase in poultry feeds is commercially mandatory currently since it significantly increases P availability from plant feedstuffs, leading to the reduction in feed costs due to a lower inclusion of phosphate sources. The increased availability of Ca, protein, amino acids, and other minerals than P has been shown as a secondary benefit from the use of phytases with a consequent reduction in excreta ( 48–52 ). In the present study, broilers fed phytase showed higher BWG and lower FCR when compared to those that were not fed the enzyme.…”

“…This allows for a greater amount of energy for growth ( 77 ). The benefits of using phytase at levels higher than 1,000 FYT have been related to higher absorption of myo-inositol with a parallel increase in the retention of dietary energy ( 48 ).…”

МИНЕРАЛЬНЫЙ ОБМЕН И МИКРОБНОЕ РАЗНООБРАЗИЕ СЛЕПОГО ОТДЕЛА КИШЕЧНИКА У ЦЫПЛЯТ-БРОЙЛЕРОВ (Gallus gallus L.) ПРИ ВКЛЮЧЕНИИ В ПОЛУСИНТЕТИЧЕСКИЙ РАЦИОН ПИЩЕВЫХ ВОЛОКОН

“…При составлении полусинтетических рационов необходимо учитывать, что микроэлементный статус организма определяется экзогенным поступлением микроэлементов с пищей в процессе нормализации внутрикишечного состава химуса (7). В результате этого, а также вследствие стремления организма к постоянству внутренней среды изменяются процессы всасывания, что приводит либо к нормализации содержание тех или иных элементов, либо к микроэлементному дефициту (8). В свою очередь, интенсивность всасывания зависит от множества условий, среди которых важное место занимает нормальное функционирование кишечной микрофлоры, способной модифицировать биодоступность микроэлементов через их аккумуляцию внутри микробных клеток и изменение значений внутрикишечного рН (9).…”