Response of YPM x Ross 708 male broilers to diets containing varying inclusions of phytase, calcium butyrate, and bacitracin methylene disalicylate from 1 to 42 days of age–Part 1: Performance, processing yields, and nutrient

Authors: GULIZIA, J - Auburn University; TERRA-LONG, M - Auburn University; KHALID, Z - Auburn University; VARGAS, J - Auburn University; BONILLA, S - Auburn University; HERNANDEZ, J - Auburn University; THUEKEAW, S - Chulalongkorn University; HAUCK, R - Auburn University; MACKLIN, K - Auburn University; DOZIER, III, W - Auburn University; McCafferty, Klint; PACHECO, W - Auburn University

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: The use of antibiotic growth promoters (AGP) such as s bacitracin methylene disalicylate (BMD) has been a helpful dietary additve for modulating microbiota and improving the performance and health of broilers. However, consumer demands to reduce the use of AGP in broiler diets has pressured producers to find dietary alternatives to help maintain the performance and health of broilers without AGP. Butyric acid (BA) or butyrate-based feed additives (calcium butyrate; CB) have been suggested due to their positive effects on pathogen control, beneficial bacteria growth, luminal pH, nutrient digestibility, growth, and oxidative stress. Additionally, exogenous phytase is a common feed additive which is almost ubiquitously included in broiler diets due to its beneficial effects on phytate-phosphorus utilization, diet costs and performance of broilers. Moreover, increasing the inclusion of phytase concentrations (500 to 1,500 FTU/kg) has been observed to produce additional benefits in broiler performance and nutrient utilization. However, limited research has evaluated the interactive effects of phytase concentrations and microbiota modulating feed additives (CB and BMD). Therefore, a study was conducted to evaluate the effects of phytase concentrations (500 to 1,500 FTU/kg) and microbiota modulating feed additive supplementation (CB and BMD; with or without) on the performance, processing yield, and nutrient digestibility of broilers during a six-week production period. Overall, supplementing diets with BMD improved broiler body weight compared with those fed CB and no MMFA from 1 to 42 d of age. However, results were dependent on phytase concentration. Feeding diets with 1,500 FTU/kg of phytase increased the digestibility of fat, phosphorus and apparent ileal digestible energy compared with those fed diets with 500 FTU/kg.

Technical Abstract: This 42-d study evaluated the effects of phytase, calcium butyrate (CB), and bacitracin methylene disalicylate 50 (BMD) on broiler performance, processing yields, and nutrient digestibility. Ross d-old YPM x 708 male broilers (2,880 total) were distributed into 72 floor pens and assigned to 1 of 9 treatments (8 replicates/treatment) on d of hatch. This experiment was a 2 x 4 + 1 factorial arrangement, including 2 phytase concentrations (500 or 1,500 FTU/kg), 4 microbiota modulating feed additive groups (MMFA; none, CB (0.5 g/kg of diet), BMD (55 ppm/kg of diet), or both CB and BMD), and a negative control without feed additives. Broiler performance (d 14, 28, and 42), apparent ileal nutrient digestibility (d 28 and 42), and processing yields (d 43) were determined. Day 14 BW increased with BMD inclusion compared to CB and no MMFA in the 1,500 FTU/kg group but BW were similar between all MMFA combined with 500 FTU/kg (P = 0.05). Supplementing BMD increased d 28 BW and reduced d 1 to 28 feed conversion ratio compared to CB and no MMFA (main effect, P = 0.05). Day 42 BW varied depending on dietary phytase concentrations. When diets contained 500 FTU/kg, broilers fed diets both CB and BMD had a higher BW than broilers fed only CB. Whereas when the inclusion of phytase was increased to 1,500 FTU/kg, broilers fed diets with only BMD or both CB and BMD had higher BW than broilers fed diets with no MMFA (P = 0.05). Phytase concentrations at 1,500 FTU/kg increased (P = 0.05) digestibility of fat (main effect, d 42), phosphorus (d 28 and 42), and apparent ileal digestible energy (AIDE; main effect, d 42) compared to 500 FTU/kg. In this study, dietary BMD improved broiler growth compared to CB and no MMFA. However, these observed differences between CB and BMD were dependent on dietary phytase concentrations.