Phytase supplementation in diets rich in fiber from rapeseed enhances phosphorus and calcium digestibility but not retention in broiler chickens

Abstract

Two experiments were conducted on broilers to assess the effect of dietary fiber from 00-rapeseed meal (RSM) on phosphorus (P) and calcium (Ca) apparent ileal digestibility (AID) and retention (AR) during the growing (Exp1: 10 to 21 d) or finishing period (Exp2: 21 to 31 d) in diets supplemented or not with microbial phytase. Each experiment involved 144 male Cobb 500 fed one of 8 diets. Fiber content was modulated by incorporating whole RSM, RSM from dehulled rapeseeds, either raw or supplemented with 2 levels of defatted rapeseed hulls. Diets were supplemented or not with 750 phytase units of microbial phytase per kg. Excreta were collected from d 14 to d 17 (Exp1) and from d 27 to d 30 (Exp2) to measure AR. At the end of experiments, digestive tracts were sampled and weighed. The distal ileum and tibias were collected to measure AID and bone mineralization, respectively. Age did not significantly alter the response of birds to the addition of dietary fiber. Inclusion of hulls decreased growth performance (P < 0.05). The weight of the proventriculus-gizzard (PG) increased with the dietary fiber content in Exp1: The decreased weight observed using dehulled RSM was reversed following the inclusion of hulls. In both trials, while the presence of phytase increased the AID of P (P < 0.001) but not Ca, the inclusion of hulls with phytase improved the AID of P and Ca [linear (Lin), P < 0.05]. This effect could depend on the effect of fiber on PG development and physiology. Hulls decreased the moisture content of excreta (P < 0.01), suggesting higher water retention or lower water consumption with fiber. The AR of P was lower than AID of P with hulls, contrary to Ca, suggesting a metabolic imbalance. The decrease of AR together with the decrease of bone characteristics indicates a lack of Ca in diets with hulls and suggests that P and Ca provision should be adapted to the level and the origin of fiber inclusion.

The effects of Moringa peregrina seed meal, autoclaving, and/or exogenous enzyme cocktail on performance, carcass traits, meat quality, and blood lipids of broilers

“…Therefore, no significant differences between the 10% autoclaved MPSM groups and the control group were observed, especially with the intestine and cecum ( p > 0.05) and, to some extent, with the gizzard. These results are in line with Bournazel et al ( 108 ) who found that the inclusion of rapeseed hulls in broilers’ diets induced higher relative gizzard weight at 21 d, while the inclusion of dehulled seeds lowered this value; and recommended using a suitable level of fibers to get beneficial effects, but it should not exceed this level to avoid negative effects on performance. It is worth noting that fibers can improve the beneficial microbial environment of the digestive system ( 106 , 107 ); however, it should be highlighted that although the presence of fibers in the feed can improve digestive system health, using them at high levels could lead to negative effects on performance.…”

Interactive effect of 2 dietary calcium and phytase levels on broilers challenged with subclinical necrotic enteritis: part 1—broiler performance, gut lesions and pH, bacterial counts, and apparent ileal digestibility

“…Birds fed the high dose of phytase (1,500 vs. 500 FTU/kg) had higher WG (day 0–14; day 0–21; day 0–28) in the present study in agreement with numerous reports that superdosing phytase improves growth ( Pillai et al., 2006 ; Amerah et al., 2014 ; Beeson et al., 2017 ; Scholey et al., 2018 ; Walk et al., 2018 ). The benefits derived from phytase supplementation at levels above recommended doses are due to increased digestibility of amino acids, energy, Ca, and trace minerals, from inactivation of phytate antinutritional properties ( Selle et al., 2000 ; Camden et al., 2001 ; Shirley and Edwards, 2003 ; Bournazel et al., 2018 ).…”

Ileal phosphorus digestibility of soybean meal for broiler chickens remains consistent across institutions in a collaborative study regardless of non-phytate phosphorus concentration in the pre-experimental starter diet

“…It is therefore possible that the Ca and P concentration in the starter diet affected the P digestion capacity of broilers in the subsequent period, contributing to variability of P digestibility values as reported by Rodehutscord et al (2017) . Additionally, fiber from SBM may have affected P and InsP digestion via soluble fraction related increased digesta viscosity, mineral binding to insoluble fiber components, or physical entrapment of substrates, that reduces the access of endogenous enzymes to substrates ( Baye et al, 2015 ; Bournazel et al 2018 ). However, because fibrous plant feedstuffs generally contain significant amounts of phytate, it is difficult to separate the effect of fiber from that of phytate as fiber at moderate concentrations improves gizzard functional development and may beneficially alter the microbiota and intestinal fermentation ( Bournazel et al, 2018 ).…”