Non-starch polysaccharides (NSPs) are present in all feed ingredients of plant origin and impair access and function of endogenous enzymes present in the gastrointestinal tract. Hence, they exert a negative impact on digestion and absorption of nutrients linked to the cell walls (Choct and Annison, 1992).
Numerous studies have shown that supplementation with appropriate microbial enzymes can eliminate the anti-nutritional effects of NSPs and improve utilisation of dietary energy and amino acids, raising performance in both broilers and layers (e.g. Geraert et al., 2003).
However, information on the efficacy of enzymes in diets for breeding hens is scanty. In recent years, feed ingredients of animal origin have been phased out in broiler breeder diets and microbial enzymes may have an important role to play.
The effects of supplementing corn-soybean meal-based broiler breeder diets with a multienzyme preparation were examined in a total of 576 Arbor Acres breeding hens (28-week old) randomly divided into four treatments: Positive control (PC, standard diet as used in the commercial breeder farm); PC + Enzyme; Negative control (NC, reducing ME by 0.29 MJ/kg and lysine by 0.07 percentage units); and NC + Enzyme.
The enzyme, included at 500 g/t diet, contained endo-1,4-ÃŸ -xylanase 2,200 visco units/g and endo-1,3(4)-ÃŸ -glucanase 200 AGL units/g plus other auxiliary activities (Rovabio Excel AP 10 percent) from single fermentation of a non-GMO fungus Penicillium funiculosum.
Measurements included laying performance, reproductive performance and digestibility of nutrients. Data were analysed by ANOVA and means were separated using the LSD procedure.
The trial was conducted from 29 to 45 weeks of age. Results showed that enzyme supplementation improved (P<0.05) laying rate, egg mass and feed conversion, with pronounced improvements observed at peak and after peak production.
Enzyme supplementation increased (P<0.05) fertility rate at week 36, the proportion of quality chicks at week 45 and the digestibility of dry matter, gross energy, neutral detergent fibre and acid detergent fibre. It is concluded that dietary supplementation with the enzyme enhanced performance of broiler breeders, through improvements in digestibility of dietary nutrients. Economic savings are also achieved through enzyme supplementation of the reformulated diet.
Article made possible through the contribution of Australian Poultry Science Symposium (APSS) 2007.