Effect of a Buttiauxella phytase on production performance in growing/finishing pigs fed a European-type diet without inclusion of inorganic phosphorus

Abstract

SummaryThe effect of a Buttiauxella phytase, in a dose range of 0-1000 FTU/kg in feed, on production performance in growing/finishing pigs fed European type wheat, corn, barley and SBM based diet was determined. Five dietary treatments were tested including a positive control (PC), a negative control (NC) without inorganic P and with reduced Ca (-0.12%) and metabolisable energy content (-0.14 MJ ME/kg) or NC supplemented with Buttiauxella phytase (Axtra ® PHY, Danisco Animal Nutrition, DuPont Industrial Biosciences, Marlborough, UK) at 250, 500 or 1000 FTU/kg respectively. A total of 100 pigs (mean initial BW of 30 kg, Topig x Pi, 10 weeks of age) were used, with 20 replicates per treatment (50% gilts and 50% barrows). Pigs were individually housed in pens and randomly allocated on the basis of body weight (BW) and gender to the five treatments. Feed, in mash form, and water were offered ad libitum. Basal diets had an intrinsic phytase level of approximately 300 and 440 FTU/kg in NC grower and NC finisher diets respectively. Mean average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) were calculated for the feeding phases of 30-85 kg (grower), 85-125 kg (finisher) on trial and for overall period. During the grower phase, increasing phytase dose resulted in a linear increase in ADG. Phytase inclusion at 250, 500 and 1000 FTU/kg improved ADG by 3.5, 7.2 and 8.1% respectively compared to NC and by 0.8, 4.5 and 5.3% respectively compared to those fed the PC. Performance in the finisher phase, overall period and slaughter parameters were not different between dietary treatments. The data showed that it was beneficial to increase phytase dose up to 1000 FTU/kg in grower pigs up to 85 kg BW. In the finisher phase, in pigs with BW above 85 kg, 500 FTU/kg was sufficient to replace inorganic P and maintain performance and carcass characteristics comparable to pigs fed the PC.

Increasing doses of phytase from Citrobacter braakii in diets with reduced inorganic phosphorus and calcium improve growth performance and lean meat of growing and finishing pigs

“…In the present study, the inclusion of phytase during the finishing periods did not improve performance when compared to the control diets, even at 3,000 FYT/kg feed. Thus, the results were similar to those found by Dersjant-Li et al [7] when working with pigs in the finishing (85–125 kg LW) using a 6-phytase from Buttiauxella sp. (250, 500, and 1,000 FYT/kg feed).…”

“…Phytase is usually added to pig diets at 500 FYT/kg [6,7], but, at this level, less than 50% of the phytate in the diet is commonly hydrolyzed. Therefore, higher inclusion levels are necessary in order to hydrolyze more than 60% of the phytate, reducing its antinutritional effects and improving efficiency of organic phosphorus utilization [2].…”

“…Considering that feed costs can reach up to 60–70% of the total cost of pig production [7], increasing the conventional dose of phytase by 1.5 to 2 times can be economically attractive when the value of nutrients being released is compared to the cost of the phytase being used [12]. Its efficacy, however, depends on several factors such as animal category, type of diet, and the phytase source [4].…”

Productive performance of commercial growing and finishing pigs supplemented with a Buttiauxella phytase as a total replacement of inorganic phosphate

“…A notable result from this study is that the phytase at 1,000 FTU/kg showed improved ADG and G:F compared with PC during grower 1 phase. Similar responses were seen in grower pigs from 30 to 85 kg BW, when Buttiauxella phytase dosed at 1,000 FTU/kg improved ADG by 5.3% vs. a positive control ( Dersjant-Li et al., 2017b ). Since the PC diet was formulated to meet the animals P requirements, the improved performance above that on the PC supports observations that the higher dose phytase could impacted the utilization of other nutrients such as energy or amino acids ( Woyengo and Nyachoti, 2013 ).…”

“…In that study, 2,000 FTU/kg phytase replaced 0.24% inorganic P from dicalcium phosphate (DCP, based on analyzed P levels) while maintaining body weight gain and feed efficiency compared with positive control (PC) in piglets. In a recent study ( Dersjant-Li et al., 2017b ), it was reported that Buttiauxella phytase at 1,000 FTU/kg could totally replace inorganic phosphate in grower pigs from 30 to 85 kg BW, fed European type wheat/barley based diets. However, limited information is available on using phytase to total replace inorganic P in commercial corn and SBM based diets in pigs raised under commercial production settings.…”