Effects of antibiotic growth promoter and dietary protease on growth performance, apparent ileal digestibility, intestinal morphology, meat quality, and intestinal gene expression in broiler chickens: a comparison

Abstract

This study aimed to evaluate the effects of supplementing broiler diets with a dietary protease on growth performance, digestive function, intestinal morphology, and meat quality as compared with feeding diets with or without an antibiotic growth promoter (AGP). A total of 240 1-day-old male chicks (Cobb 500, 48.3 ± 3.3 g) were distributed to 3 treatments with 8 replicates (10 birds per replicate). Three treatments were: 1) corn-soybean meal basal diets (CTRL); 2) basal diets with 0.003% avilamycin (AB); 3) basal diets with 0.0125% protease (PRT). The diets were provided as mash form, and birds were fed ad libitum during the whole experimental period. On d 45, birds were euthanized, and tissue and digesta samples were collected. On d 46, the remaining birds were processed in a commercial slaughterhouse, and breast muscle samples were collected. Despite a trend for a decreased feed conversion ratio (FCR) in the AB group during the whole phase (P = 0.071), no significant differences in growth performance parameters and relative weights of organs were observed (P > 0.05) among the groups. The AB and PRT groups showed significantly greater apparent ileal digestibility of amino acids compared with the CTRL group (P < 0.05). The PRT group significantly improved the morphology of duodenum and jejunum (P < 0.05). No differences were detected for meat quality, white striping and woody breast among the groups (P > 0.05). For the gene expressions, the AB group showed a greater level of B0-system neutral amino acid co-transporter 1 (B0AT1) and excitatory amino acid transporter 1 (EAAC1) mRNA abundance compared with PRT group while a significantly lesser level of cationic amino acid transporter 1 (CAT1) mRNA abundance was observed in the AB group compared with CTRL group (P < 0.05). The PRT group had a lesser level of peptide transporter 1 (PepT1) mRNA abundance in the jejunum than the CTRL group (P < 0.05). The highest mRNA abundances of zonula occludens-1 (ZO1) and cadherin 1 (CDH1) were observed in the CTRL group (P < 0.05). In conclusion, supplementation of avilamycin tended to reduce FCR and significantly improved amino acids utilization and supplementation of dietary protease significantly enhanced intestinal morphology and amino acids utilization in broilers. In that respect, exogenous protease use appears to be an interesting tool to be considered in AGP reduction strategies.

Effects of red-osier dogwood extracts on growth performance, intestinal digestive and absorptive functions, and meat quality of broiler chickens

“…After WS and WB scoring, samples were placed in labelled plastic bags, stored in ice, and transported to the lab. In the lab at 2 °C and 24 h postmortem, the samples were further subdivided to obtain five sub-samples that were used for meat quality analyses (Lu et al, 2020). Starting from the right breast, the first subsample was cut from the cranial section (8 × 4 × 2 cm 3 ) and used to assess ultimate pH and myofibrillar fragmentation index (MFI).…”

“…The thermal cycle was set as; 95° C for 3 min, 40 cycles at 95° C for 20 s, 60° C for 30 s, and 72° C for 30 s and the data was analyzed using the 2 delta delta method after normalization against the reference gene (Livak and Schmittgen, 2001). The sequences of primers for the genes tested were designed according to Lu et al (2020), and the sequences are located in GenBank.…”

Effects of Tannic Acid Supplementation on Growth Performance, Oocyst Shedding, and Gut Health of in Broilers Infected with Eimeria Maxima

“…Diverse tannin sources such as chestnut ( Castanea sativa ; hydrolysable tannin) and quebracho ( Schinopsis lorentzii ; condensed tannin) are known to control Eimeria infections [ 14 , 15 , 16 ]. Hydrolysable and condensed tannins have different bioavailability because condensed tannins cannot be hydrolyzed into small molecules in chickens [ 17 ]. Although high doses (>5 g/kg) of tannins have cytotoxicity and are considered as anti-nutritional factors in chickens, tannins at appropriate dosages are also known to show beneficial effects by exhibiting strong antimicrobial, antioxidant, and anti-inflammatory effects in chickens [ 17 ].…”

“…Hydrolysable and condensed tannins have different bioavailability because condensed tannins cannot be hydrolyzed into small molecules in chickens [ 17 ]. Although high doses (>5 g/kg) of tannins have cytotoxicity and are considered as anti-nutritional factors in chickens, tannins at appropriate dosages are also known to show beneficial effects by exhibiting strong antimicrobial, antioxidant, and anti-inflammatory effects in chickens [ 17 ]. Tannins can limit the growth of microorganisms by directly inhibiting activities of microbial enzymes and by indirectly forming complex with metal ions [ 18 , 19 ].…”

Productive Performance and Cecum Microbiota Analysis of Broiler Chickens Supplemented with β-Mannanases and Bacteriophages—A Pilot Study

“…The use of growth factors in poultry has been a common practice to increase productivity and efficiency; however, in recent years due to the growing concern of the development of microbial resistance, its use is under regulation [ 34 , 35 ].…”