APSS 2013 Proceedings - The University of Sydney

Aust. Poult. Sci. Symp. 2013.....24
Diversity within feed ingredients is well known, and results from differences in
cultivar, country of origin, year to year variation as well as from processing (e.g. oilseed
meals). As an example, soybean meals have been shown to vary considerably in nutritional
value (De Coca-Sinova et al, 2008) and, due to this variation, the effect of a protease can also
be expected to vary when testing different batches of soybean meals (Figure 6). The various
soybean meal batches were incubated in an in vitro digestion system and protease effect on
top of endogenous enzymes (pepsin and pancreatic enzymes) was analyzed as increase in
DH. Error bars indicate standard deviation and asterisks indicate a significant impact of the
protease (P < 0.05; Tukey HSD test). (Pettersson and Pontoppidan, 2012)
Degree of hydrolysis (%)
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Control
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Protease supplementation
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SBM-1, Brazil SBM-2, Brazil Fullfat SBM, Brazil SBM, US
Figure 6 - Increase in degree of protein hydrolysis (DH, %) by a mono-component protease dosed at 100 mg
purified enzyme protein per kg of SBM (n = 5).
To verify if the strong protein hydrolyzing effects demonstrated by this protease in
vitro, could be replicated in chickens, Carvalho et al. (2009) and Bertechini et al. (2009a, b)
carried out a follow up study with a series of in vivo trials. They used and adapted a method
reported by Matterson et al. (1965) in which birds were fed a reference diet and whole
portions of this reference diet were replaced by a different feed raw material. Birds were fed
diets supplemented with 200 ppm of the protease. Excreta samples were collected and the
digestibility of the raw materials was determined.
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