Phytase Application to Feeds
Studies have shown the value of phytase in improving phosphorus
utilization of feedstuffs and that many nutrients, enzymes and microorganisms
are not stable through the pelleting and extrusion feed processing steps.
The objective of this study was to determine the post-pellet adhesion
of a powdered phytase and bacteria applied to pellets. The test material
contained 1000 PU/g of phytase activity and 8.7 log10 cfu Lactobacillus
plantarrum per gram. The test products were applied immediately after
the fat coating in a screw conveyor at the rate of 250 grams per minute.
The feed flow rate was approximately fifteen tons per hour. The fines
were separated from the whole pellets in order to determine the amount
of product that adhered to the pellet. In this study, 98.6 percent of
the enzyme activity remained adhered to the pellets whereas only 1.4
percent of the activity was associated with the fines. There was no
difference in the bacterial treatment between the whole pellets and
screened fines. The results of this study indicate that heat-labile
feed additives can be applied to pelleted or extruded feeds with little
loss in activity.
Pierce, J.I., C.A. Moran and A.E. Sefton. 2003. Dry post-pellet
application of heat-labile products to livestock diets. Proc. Aust.
Poultry Sci. Sym. 15:119-121.
