Effect of sodium sources and exogenous phytase supplementation on growth performance, nutrient digestibility, and digesta pH of 21-day-old broilers

Coccidia Vaccine Challenge and Exogenous Enzyme Supplementation in Broiler Chicken 2-Effect on Apparent Ileal Nutrient and Energy Digestibility and Intestinal Morphology 7 and 14 Days Post-Challenge

The effect of exogenous mixed-enzyme supplementation (xylanase, β-glucanase, and pectinase) and coccidia vaccine challenge (CVC, Coccivac B-52™) on broilers fed a corn-SBM (CS) and a wheat-CS (WCS)-based diet was examined in this study. On day 14, 448 Cobb by-product breeder male broiler chickens were assigned to treatments (factorial arrangement) in a completely randomized design, with each treatment replicated seven times. Treatment effect was evaluated within each diet type as a 2 (enzyme levels) x 2 (CVC, 0 or 20X) factorial arrangement of treatments 7 and 14 days post-CVC. The 7-day (days 14-21) post-CVC, BWG, and feed efficiency (birds on the CS-based diet) were lower (p < 0.05), while birds on enzyme-supplemented diets had higher (p < 0.05) BWG compared to birds on diets without enzyme supplementation. Between days 21 and 28, an interaction between CVC and exogenous enzyme resulted in higher (p < 0.05) BWG compared with the challenged birds fed diets without enzyme supplementation. For birds fed WCS-based diets, CVC influenced (p < 0.05) BWG and feed efficiency (decreased days 14-21 and increased days 21-28), while CVC birds had higher BWG and feed efficiency 14 days post-CVC. Apparent ileal digestibility of dry matter, energy, and DE were lower (p < 0.05) in CVC broilers fed either the CS- or WCS-based diets (7 and 14 days post-CVC). Interaction between CVC and exogenous enzyme supplementation indicated that CVC, irrespective of exogenous enzyme supplementation with the WCS-based diet, decreased (p < 0.05) Ca utilization (7 days post-CVC) but increased (p < 0.05) Ca utilization compared to CVC birds without enzyme supplementation 14 days post-challenge. Seven days post-CVC, irrespective of the diet type, CVC resulted in lower (p < 0.05) duodenal VH and VH:CD and higher (p < 0.05) CD. Enzyme supplementation influenced (p < 0.05) duodenal CD (increased) and VH:CD (decreased) in birds fed the WCS-based diet. Results from this study showed that complete recovery from CVC was influenced by diet type, with CVC birds fed WCS-based diet having higher BWG and feed efficiency compared to the unchallenged birds.

Hypothetical proteins of chicken-isolated Limosilactobacillus reuteri subjected to in silico analyses induce IL-2 and IL-10

Lactic acid bacteria (LAB) probiotics are health-promoting but their characteristics, safety profile and functional mechanisms are not fully understood. Hence, this study aimed to characterize some hypothetical proteins of the chicken-isolated Limosilactobacillus reuteri genome and unravel their IL-2 and IL-10-inducing potential to understand mechanisms of their immunological functionality for sustainable applications. The selected proteins were subjected to in silico analyses for transmembrane topology, sub-cellular localization, IL-2 and IL-10-inducing ability and IL-2 and IL-10 gene expression across various conditions. IL-2 and IL-10-inducing mutants were statistically analyzed using a one-way analysis of variance of a general linear model of SAS and statistical significance was set at p < 0.05. The analyzed proteins are stable under a wide temperature range. All the hypothetical proteins are IL-2 and IL-10-inducing but QHPv.2.12, QHPv.2.13 and QHPv.2.15 are non-immunogenic. The evaluated mutants are IL-2 and IL-10-inducers but QHPv.2.13 and QHPv.2.15 are not immunogenic. This study sheds light on understanding the functional mechanisms of chicken-isolated L. reuteri and suggests it or its proteins as potent candidates for feed additive and therapeutic purposes.

Digestible calcium equivalency of phytase and nutrient utilization of broiler chickens fed graded levels of limestone or phytase during the starter phase

The current study aimed to quantify the digestible calcium (Ca) equivalency of a new phytase (HiPhorius) in broiler chickens. A total of 1,152 male Cobb 500 broiler chickens were used in an experiment in which 8 diets consisting of graded levels of Ca supplied with limestone or graded levels of the phytase were fed. The 8 dietary treatments were based on a corn-soybean meal diet containing 5.1 g/kg of Ca and 5.1 g/kg of phosphorus (P) as negative control (NC); the NC + 1.3, 2.6, or 3.9 g/kg of Ca from limestone; and the NC + 500, 1,000, 2,000, or 4,000 FYT/kg of phytase. Birds were fed the experimental diets for 3 d (from d 7 to 10) or 14 d (from d 7 to 21) to determine apparent ileal digestibility (AID) and apparent total tract retention (ATTR) of dry matter (DM), CP, Ca, and P. In the 10-day-old birds, increasing the levels of Ca decreased the AID of P and Ca (linear, P < 0.05). Increasing the levels of phytase quadratically improved (P < 0.05) the AID of Ca and P. The AID of DM and CP in the younger birds quadratically increased (P < 0.05) as the levels of Ca increased. There were linear and quadratic effects (P < 0.05) of increasing phytase level for the AID of DM and a linear effect (P < 0.05) for the AID of CP. In the 21-day-old birds, increasing Ca levels resulted in a linear decrease (P < 0.05) in the AID of CP and P, and a quadratic decrease (P < 0.05) in the ATTR of CP. Increasing phytase levels linearly and quadratically (P < 0.05) improved the AID and ATTR of CP, P, and the ATTR of Ca. The analyzed phytase activity in the diets supplemented with phytase ranged from 1,520 to 7,661 FYT/kg. The digestible Ca equivalence for dietary phytase at 1,520 to 7,661 FYT/kg ranged from 1.55 to 2.02 g/kg in the 10-day-old birds fed for 3 d and from 0.52 to 0.64 g/kg in 21-day-old birds fed for 14 d. The results showed the reduction in Ca level that could be accommodated by phytase supplementation, which is markedly different between the younger and older birds. Feeding duration influenced the impact of phytase supplementation on Ca and P digestibility, with better efficacy of phytase observed in the 10-day-old birds fed for 3 d. Also, the results showed the extra-phosphoric effects of phytase on the utilization of other essential nutrients such as protein and Ca.

The Contribution of Phytate-Degrading Enzymes to Chicken-Meat Production

The contribution that exogenous phytases have made towards sustainable chicken-meat production over the past two decades has been unequivocally immense. Initially, their acceptance by the global industry was negligible, but today, exogenous phytases are routine additions to broiler diets, very often at elevated inclusion levels. The genesis of this remarkable development is based on the capacity of phytases to enhance phosphorus (P) utilization, thereby reducing P excretion. This was amplified by an expanding appreciation of the powerful anti-nutritive properties of the substrate, phytate (myo-inositol hexaphosphate; IP₆), which is invariably present in all plant-sourced feedstuffs and practical broiler diets. The surprisingly broad spectra of anti-nutritive properties harbored by dietary phytate are counteracted by exogenous phytases via the hydrolysis of phytate and the positive consequences of phytate degradation. Phytases enhance the utilization of minerals, including phosphorus, sodium, and calcium, the protein digestion, and the intestinal uptakes of amino acids and glucose to varying extents. The liberation of phytate-bound phosphorus (P) by phytase is fundamental; however, the impacts of phytase on protein digestion, the intestinal uptakes of amino acids, and the apparent amino acid digestibility coefficients are intriguing and important. Numerous factors are involved, but it appears that phytases have positive impacts on the initiation of protein digestion by pepsin. This extends to promoting the intestinal uptakes of amino acids stemming from the enhanced uptakes of monomeric amino acids via Na⁺-dependent transporters and, arguably more importantly, from the enhanced uptakes of oligopeptides via PepT-1, which is functionally dependent on the Na⁺/H⁺ exchanger, NHE. Our comprehension of the phytate-phytase axis in poultry nutrition has expanded over the past 30 years; this has promoted the extraordinary surge in acceptance of exogenous phytases, coupled with the development of more efficacious preparations in combination with the deflating inclusion costs for exogenous phytases. The purpose of this paper is to review the progress that has been made with phytate-degrading enzymes since their introduction in 1991 and the underlying mechanisms driving their positive contribution to chicken-meat production now and into the future.