Higher levels of phytase increased feed efficiency by 1% on live and carcass weight basis, as well as improving growth rate on a live weight basis and on a carcass weight basis

Boyd, Dean

Elsbernd, Amanda

Gould, Stacie

Holloway, Cassie

Patience, John

Zier-Rush, Cate

Higher levels of phytase increased feed efficiency by 1% on live and carcass weight basis, as well as improving growth rate on a live weight basis and on a carcass weight basis.This article is published as Patience, J.F., S. Gould, C. Holloway, R.D. Boyd, C. Zier-Rush and A, Elsbernd. Super-dosing phytase improves grow-finish performance.  National Hog Farmer. March 22, 2017. Posted with permission.</p

Digital Repository @ Iowa State University (ISU)

2/17/2021 Super-dosing phytase improves grow finish performancehttps://www.nationalhogfarmer.com/print/16872 1/3By John Patience, Stacie Gould and Cassie Holloway, Iowa State University; and Dean Boyd,Cate Zier-Rush and Amanda Elsbernd, The Hanor Co.National Pork BoardSuper-dosing phytase improves grow finish performanceHigher levels of phytase increased feed e ciency by 1% on live and carcass weightbasis, as well as improving growth rate on a live weight basis and on a carcass weightbasis.Mar 22, 20172/17/2021 Super-dosing phytase improves grow finish performancehttps://www.nationalhogfarmer.com/print/16872 2/3Last month, we discussed adding phytase at super-dosed levels to nursery diets, and reportedsubstantial benefit from this practice. However, the results of research on super-dosing phytase ingrowing diets are less definitive.To try to better answer the question, a study was conducted in a commercial research barn with2,200 mixed sex pigs fed from 81 pounds to market at about 270 pounds. The test diets containedcorn and soybean meal with 15% wheat middlings. The positive control diet was formulated to bebalanced for energy and all nutrients, while the negative control diet contained 15 pounds less fatper ton and 0.15% less SID lysine. Both the positive and negative control diets were formulated tocontain 225 FTU phytase per pound.However, our negative control diet was not quite what we had expected; the phytase productcontained much higher levels of phytase than indicated on the label, so the negative control dietcontained about 500 FTU phytase per pound rather than the formulated 225 FTU per pound. Thus,the negative control diet already contained phytase approaching the lower end of what would beconsidered super-dosed levels. The super-dosed diets, of which there were three, contained 680,1,034 and 1,134 FTU per pound.Even so, the higher levels of phytase increased feed efficiency by 1% on both a live (P = 0.028) andcarcass weight basis (P = 0.040). The higher levels of phytase also tended to improve growth rateon a live weight basis (P = 0.076) and on a carcass weight basis (P = 0.067). The elevation in gainresulted in an additional 2 pounds of carcass weight sold at closeout (P = 0.043).This study did not really evaluate the impact of super-dosing, because of the higher-than-expectedlevel of phytase in the control diet. However, it did demonstrate that exceeding 500 FTU of phytaseper pound can be beneficial, and the magnitude of the improvement can be financiallyadvantageous to the producer.It is important to differentiate between the use of phytase to meet the pig’s basic requirement forphosphorus, and to use it at super-dosed levels to advance pig performance for reasons notexplained by improved phosphorus availability. Phytase is routinely added to pig diets whensupplemental phosphorus is needed to meet the pig’s requirement for phosphorus and thus avoiddeficiency symptoms. Whenever the basal ingredients in a diet — such as corn and soybean meal— do not supply enough phosphorus, nutritionists previously would add monocalcium or dicalcium2/17/2021 Super-dosing phytase improves grow finish performancehttps://www.nationalhogfarmer.com/print/16872 3/3Source URL: https://www.nationalhogfarmer.com/animal-health/super-dosing-phytase-improves-grow-finish-performancephosphate. Now, nutritionists will select phytase ahead of these mineral supplements because it ismuch less expensive, and better for the environment.Typically, 250 to 500 FTU phytase per pound of diet are used for this purpose. Now, monocalcium ordicalcium phosphate are only added to the diet when phytase cannot fully meet the pig’srequirement for phosphorus.There is one note of caution when using phytase. Excess calcium has been shown to diminish theability of phytase to release phosphorus. Indeed, if calcium becomes too high in the diet, phytasecan become completely ineffective. There is a growing body of information on the correct ratio ofcalcium to phosphorus, but for example, a 1.5:1 ratio of calcium to total phosphorus has beenshown to reduce phytase effectiveness by about 50% and a ratio of 2.3:1 totally negated the valueof phytase in the diet (Beaulieu et al., 2007).References Beaulieu, A.D., M.R. Bedford and J.F. Patience. 2007. Supplementing corn or corn-barley diets withan E. coli derived phytase decreases total and soluble P output by weanling and growing pigs. Can.J. Anim. Sci. 87:353-364.

Super-dosing phytase improves grow finish performance

https://dr.lib.iastate.edu/handle/20.500.12876/93521

Super-dosing phytase improves grow finish performance

Abstract

Similar works

Full text

Available Versions

Digital Repository @ Iowa State University (ISU)