Effects of Adding Different Levels of Phytase to Diet Containing Low Phosphorus on Performance, Shell Quality and Bone Parameters in Laying Japanese Quail
Abstract
This experiment was carried out to determine the effect of addition of different levels of phytase containing low phosphorus diets on performance, eggshell quality and bone characteristics in laying Japanese quail (Coturnix japonica). In the experiment, a total of 162 7-week-old laying Japanese quail were fed two different diets containing 0.33% available phosphorus (AP, control) and 0.15% AP supplemented with phytase 0, 500, 1000, 1500, 2000 phytase unites/g feed. Each diet was feed to groups having three replicates, each cages nine quail, in completely randomized design. Feed and water supplied for ad-libitum. Light was provided 17 hours daily. Egg production, egg mass, average daily feed consumption, viability, fat-free dried tibia weight were improved, as phytase level increased in the diet. However, final live weight, carcass weight, body weight gain, feed efficiency, tibia ash (%) and deformed egg ratio (%), some eggshell quality parameters measured in eggs collected at the end of the first period, were not affected by treatments. With regard to measured parameters, the responses of laying quail, to the increasing phytase levels, were not linear. The performance and bone parameters of the group fed with 1500 units were very close to that of the control group, even higher than the control group in some traits. Decreasing in shell weight of eggs collected at last three days of the experiment were not prevented any of the phytase levels. At the same period, shell thickness and breaking strength of the eggs of groups fed with 1500 and 2000 units phytase, were significantly lower than that of the control group. Manure ash percentage of phytase added groups were significantly lower than the control group.
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Introduction
In order to improve production, nutritionists endeavor to increase digestibility, availability of nutrients in the diet and to obtain more product consumed per unit feed, and therefore they consider total nutrient intake and retention as well as waste output. Although poultry is highly efficient in converting feed to egg or body gain, the presence of components such as antinutritional factors and indigestible nutrients in the feed may reduce production efficiency. These components in the feeds reduce nutrient digestibility and availability by either chemically or physically binding nutrients or by direct toxic action the animal (Nelson, 1971; Adeola and Cowieson, 2011). Availability of phosphorus (P) for monogastric animals in feed ingredients of plant origin is much lower than the P content of those ingredients, because of the greater portion of their total P is present as phytate. Phytate or phytic acid is both an antinutritional factor and an indigestible nutrient (Adeola and Cowieson, 2011). The P contained in the molecule is very low availability to monogastric animals, especially poultry. Because of its chelating ability with essential mineral elements such as zinc, manganese, iron, calcium, potassium, and proteins, phytate reduces the availability of these nutrients through the formation of indigestible complexes (Nelson, 1967).
Recently advances in enzyme technology have led to the development enzyme products to be used as feed additives. Many fungi, bacteria, and yeasts naturally produce the enzyme phytase and some of them already on the market. Nelson et al. (1971) found that when the preparation of phytase made from Aspergillus ficuum was added to acorn-soybean diet containing low P, phytate phosphorus was almost completely hydrolyzed by the chickens. Recently, heightened environmental concerns over phosphates in animal waste have renewed the interest phytase (Sharpley et al., 2004; Toprak and Yilmaz, 2016) and many research with broiler (Yan et al., 2003) and quail (Sacakli et al., 2006; Saima et al., 2014) were conducted demonstrating enhancements of P availability by phytase addition to diets. Newkirk and Classen (1992) suggested that when phytase and xylanase enzymes were added to diets containing different levels of total P (0.4, 0.5, 0.6, 0.7%) in the laying hens, phytase reduced the feed efficiency and interacted with xylanase to influence egg production. Konca and Bahtiyarca (1996), Bahtiyarca and Parlat (1997), Sacakli et al. (2006) showed that when the diets have low P were supplemented with phytase, body weight gain, feed conversion ratio was increased and also bone ash and strength were comparable with the control diet has adequate P. On the other hand, with addition of phytase to poultry diets sometimes revealed controversy results (Adeola and Cowieson, 2011). Therefore the objective of the present study was to determine the effects of different levels of phytase addition to a diet containing low P on the performance, shell quality and bone characteristics in laying Japanese quail.
Conclusion
Low dietary AP concentration may reduce production parameters in quail. The phytase addition to quail diets may help to improve production parameters. Tibia weight may decrease with low AP diets. Manure P content may be decreased via lower AP content in diets.
