Effects of Phyzyme XP and Avizyme 1502 on the Performance of Broiler Breeders and their Progeny

Four experiments were conducted to develop a better understanding of the effect of the inclusion of a phytase enzyme product (Phyzyme XP; PXP) and a carbohydrase/protease cocktail (Avizyme 1502; XAP), alone or in combination, on the productive performance of broiler breeders (broiler parent stock) and their broiler progeny as affected by mineral and nutrient availability to both parent and progeny, maternal effects on the progeny, and interactions with other feed ingredients. The inclusion of 550 units of phytase (FTU) per kg of broiler breeder layer feed increased the absolute difference in fecal moisture (FM) by 10% after been fed for 14 d. It was hypothesized that the cause was either an inappropriate calcium:non-phytate phosphorus ratio (Ca:NPP) as no Ca matrix value was assigned to PXP (Manuscript I) or a hygroscopic effect. Also, the same inclusion level caused the birds to excrete less di- and tri-valent cations and more P possibly due to a lower P requirement of the breeder strain used. Inclusion of PXP and XAP to marginally nutrient deficient broiler breeder layer diets negatively affected reproductive performance and survivability (Manuscript II) probably as a result of heat stress feed management practices and/or protease-protease inhibitor imbalances in the gut. However, when appropriate preventive management measures were taken no negative effect of PXP and XAP was observed on performance or survivability (Manuscript III). Overall, no added benefit on breeder performance was observed when enzymes were included in the breeder diet. Conversely, feeding the parental flock with diets that included PXP and XAP resulted in an improved AdjFCR of the progeny at 49 d of age (Manuscript III). Inclusion of PXP and XAP in the broiler diets increased male body weight and tended to improve feed efficiency at 41 d of age (Manuscript II). On the other hand, XAP in the presence of 0.43% Cl tended to improved feed efficiency and body weight at 35 d of age versus the enzyme fed with 0.28% Cl (0.35% NaHCO3) (Manuscript IV). This benefit disappeared by 41 d of age probably due to down-regulation of endogenous digestive enzymes. The data suggested that XAP worked better in low dietary electrolyte balance (or high chlorine content) diets.;In summary, the addition of PXP and XAP to the feed of the broiler breeder parental flock or the progeny did not negatively affect broiler breeder or broiler progeny performance when good heat stress management was practiced. It was concluded that the addition of PXP and XAP to broiler breeder and broiler diets was a potentially safe option to reduce feed cost and inorganic P inclusion in feed, when potential interactions with feed ingredients were taken in consideration.