Endogenous enzyme activities and tibia bone development of broiler chickens fed wheat-based diets supplemented with xylanase, β-glucanase and phytase

Abstract

29Objective: This study assessed the effect of different levels of xylanase, β-glucanase and phytase on intestinal 30 enzyme activities and tibia bone development in broiler chickens fed wheat-based diets. 31Methods: Twelve experimental diets were formulated using a 3 × 2 × 2 factorial design (three doses of phytase and 32 two doses of both xylanase and β-glucanase) and offered to 648 day-old Ross 308 male chicks having 6 replicates 33 groups with 9 birds per replicate and lasted for 35 days. 34Results: An interaction between the enzymes products improved (p<0.01) the activity of chymotrypsin. Protein 35 content at d10 was highest (p<0.001) with addition of phytase while general proteolytic activity (GPA) (p<0.02) and 36 lipase activity (p<0.001) were decreased. At d24, there were improvements in protein content (p<0.01) and lipase 37 (p<0.04) with supplementation of superdose phytase. Addition of superdose phytase decreased in chymotrypsin 38 (p<0.02), trypsin (p<0.01) and GPA (p<0.001). The optimum dose of xylanase decreased the chymotrypsin activity 39 (p=0.05), while the GPA (p<0.001) was increased with the optimum level of β-glucanase. Superdose phytase 40 supplementation at d10 improved maltase (p=0.05), sucrase (p<0.001) and alkaline phosphatase (p<0.001) activities 41 in the jejunum while aminopeptidase activity was highest (p<0.005) with the low level of phytase. Protein content of 42 jejunum mucosa was bigger (p<0.001) in birds fed superdose phytase while maltase activity (p<0.001) at d24 was 43 reduced by this treatment. Sucrase (p<0.04) and aminopeptidase activities (p<0.001) improved when diets 44 supplemented with low levels of phytase. Tibia bone breaking strength was highest (p<0.04) with addition of low 45 level of superdose phytase or optimum level of β-glucanase. Bone dry matter content decreased (p<0.04) when diets 46 supplemented with phytase. 47Conclusion: From the results obtained in this study, supplementation of superdose phytase was the most effective, 48 however, the cost-benefit analysis of the use of such a dose needs to be evaluated. 50Wheat is an important energy source in poultry diets in many regions of the world, including Europe, 54Canada, Australia and New Zealand. However, the nutritive value of wheat is limited by its content of soluble non-55 starch polysaccharides (NSP), which are indigestible and impede the digestion of other nutrients. Like most grains, 56 wheat also contains phytate, the main reservoir of phosphorus, which is not digested by birds due to their limited 57 secretion of phytase [1]. The exogenous enzymes that were used in this study, xylanase, β-glucanase and phytase, are 58 now extensively used as additives in poultry diets and their physical effects are generally well understood, but the 59 mechanisms behind their actions are still being researched. Research results to date have been used to determine or 60 predict the optimum dose of xylanase and β-glucanase enzymes in wheat-and barley-based diets and efforts have 61 been made to set the same for phytase...

The Growth Performance, Nutrient Digestibility, Gut Bacteria and Bone Strength of Broilers Offered Alternative, Sustainable Diets Varying in Nutrient Specification and Phytase Dose

“…While this current trial does not report differences in FCR, we did observe that phytase superdosing improved the FI and body weight gain of birds by 159 g/day and 192 g/day, respectively, during the starter/grower period and again by 79 g/day and 166 g/day, respectively, when considered from 0 to 42 days, to levels equivalent to or sometimes exceeding birds offered the PC2 diet. This adds to the already widely documented evidence that phytase superdosing in diets reduced in available P improves bird performance [2,9,12,13,23,24,48].…”

“…In recent work [9], the addition of phytase even in low doses of 250 FTU/kg yielded a 6.6% and 9.5% increase in P digestibility by day 14 and 28, respectively, and improved the digestibility of all amino acids in birds by 28 days of age. This increased access and improved digestibility of available nutrients, energy and amino acids explains the consistent evidence that the addition of phytase to broiler diets leads to improvements in growth performance (i.e., increased weight gain and improved feed efficiency) and bone parameters such as increased strength and bone ash [2,4,[9][10][11][12][13].…”

Responses of Broiler Chickens Fed Low or High Non-Starch Polysaccharide Diets and the Addition of Humic Substances from a Worm Compost

“…3). When chickens are fed high dietary levels of ingredients with high NSPs content such as DDGS and WB, poor performance and lower ileal digestibility of dietary components (Liu et al, 2011;Wickramasuriya et al, 2019;Szambelan et al, 2020;Al-Qahtani et al, 2021), higher intestinal and cecal microbiota abundance as well as greatermicrobial fermentations have been reported (Abudabos et al, 2017;Pérez et al, 2011). For these reasons, high dietary inclusion of feed ingredients with HNSPs is not recommended in broiler chickens due to the negative effects caused on the growth performance.…”

Intestinal nutrition: role of vitamins and biofactors and gaps of knowledge

“…It is also the end product of complete degradation of dietary phytic acid (myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate) by phytases or phosphatases in the intestine. The enzymes responsible for phytate degradation can be intrinsic (contained in the plant-based feed ingredients) ( Leytem et al, 2008 ), endogenous (host-derived) ( Sommerfeld et al, 2019 ), intestinal microbiome-derived ( Borda-Molina et al, 2016 ), or exogenous (as microbially-derived commercial phytase products) ( Bello et al, 2019 ; Pongmanee et al, 2020 ; Al-Qahtani et al, 2021 ). As the digestive tract matures, the capacity for dietary phytate degradation increases, even in the absence of exogenous phytase.…”