Effect of supplemental phytase and xylanase in wheat-based diets on prececal phosphorus digestibility and phytate degradation in young turkeys

Abstract

This study aimed to investigate the effect of phytase and a combination of phytase and xylanase on the prececal phosphorus digestibility (pcdP) of wheat-based diets in turkeys. A low-P basal diet (BD) based on cornstarch and soybean meal, and 2 diets containing 43% of different wheat genotypes (genotype diets GD6 or GD7) were fed to turkeys from 20 to 27 d of age. Diets were fed either without enzyme supplementation or supplemented with phytase (500 FTU/kg) or a combination of phytase and xylanase (16,000 BXU/kg). At 27 d of age, digesta were sampled from the lower ileum of animals to determine pcdP and pc myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate) (InsP6) disappearance, and to analyze the concentrations of lower inositol phosphate isomers. Similar pcdP was observed in non-supplemented BD and GD (∼36%). Phytase alone increased the pcdP in all diets by 8 to 12%, but a beneficial effect of xylanase was found only for BD. Similar results were found for pc InsP6 disappearance, although xylanase addition compared to phytase alone decreased pc InsP6 disappearance in GD7 compared to phytase alone. Animals fed GD7 performed better than those fed GD6; however, these differences could not be linked to the pcdP. The pattern of lower inositol phosphates in digesta also changed with enzyme supplementation, resulting in lower proportions of InsP5 and higher proportions of InsP4. Phytase alone decreased Ins(1,2,3,4,6)P5 but increased D-Ins(1,2,3,4,5)P5 and D-Ins(1,2,5,6)P4 concentrations. An additional increase in D-Ins(1,2,3,4,5)P5 and D-Ins(1,2,5,6)P4 concentrations was achieved with xylanase, although for the former isomer, this was observed only with GD. These results indicate that enzyme supplementation alters the pc degradation of InsP6, and that combining both enzymes had a minor additional effect on the pcdP from wheat-based diets when compared to phytase alone.

Impact of Multienzymes Dose Supplemented Continuously or Intermittently in Drinking Water on Growth Performance, Nutrient Digestibility, and Blood Constituents of Broiler Chickens

“…The use of enzymes in feed to overcome the anti-nutritional factors, to increase feed utilization, and to improve performance as well as to decrease stress has received considerable attention [3,4,8,11,16,43]; so, also is the use of enzymes in water [26][27][28][29], with water application inducing superior performance [24]. This advantage may be due to faster distribution, application, and availability [24,25] and greater use of water as well [27].…”

“…Enzymes are commonly employed to decrease anti-nutritional substances and to improve animal performance [8][9][10][11]. Multienzymes containing carbohydrases and phytase were found to enhance the utilization of energy, protein, and minerals by chickens [12][13][14], suggesting that higher amounts of alternative feedstuffs could be used in the presence of enzymes [15].…”

“…Evidently, enzyme additions to corn, wheat, barley, and rye diets have been shown to significantly improve body weight gain (BWG) and feed conversion ratio (FCR) in broilers [11,16,18]. Generally, these enzymes are hypothesized to work in two steps, described as an ileal phase and a cecal phase [19,20].…”

Monitoring the Activity of Feed Enzymes in Vitro and Their Activity in the System that Modulates the GIT

“…There is a pattern that confirms the diminishing effectiveness of the subsequent addition of each new activity to a multienzyme preparation; therefore, the effect of multienzyme additives cannot be predicted by adding up the effectiveness of each enzyme. [10]…”

“…In scientific studies, some cases have observed the lack of advantages of the enzyme compositions tested, compared with preparations with a single activity. Thus, the inclusion of 2-3 enzyme preparations in the compound feed recipe on the basis of information about the action of each individual to increase productivity is not always justified [10][11][12][13][14]. Effective combinations of the activities must be established in scientific trials and then confirmed in practical terms.…”