Bacitracin, Bacillus subtilis, and Eimeria spp. challenge exacerbates woody breast incidence and severity in broilers

Oxidative stress-induced changes in wooden breast and mitigation strategies: A review

Wooden breast (WB) is a multifactorial muscular abnormality resulting from the interplay between genetic predispositions for rapid growth, physiological stress, and anatomical impairments. This myopathy has been a persistent challenge in the poultry industry since its initial identification a decade ago. WB negatively impacts meat quality, leading to increased toughness and reduced nutritional value. Building on foundational research utilizing multiomics technologies, hypoxia-induced oxidative stress has been identified as a key early event driving the pathological processes of WB. This review provides a comprehensive overview and the state-of-the-art evidence on the pivotal role of oxidative stress in WB myopathy. It begins by examining the generation of reactive intermediates that induce oxidative damage and the host's defense mechanisms aimed at mitigating these threats. The discussion then focuses on the consequences of oxidative damage for mitochondria, protein and lipid oxidation, connective tissue remodeling, and inflammation-pathological hallmarks of WB-affected muscles. Additionally, the review highlights how oxidative stress influences satellite cell behavior, impairing the repair and regeneration of muscle tissues, a process implicated in WB. Finally, efforts to prevent or mitigate WB myopathy are summarized, with particular attention to potential intervention strategies targeting oxidative stress. These include innovative feed formulations and gut microbiota modulation, which show promise in alleviating the severity of the condition.

Effect of Adding Cordyceps sinensis Extract and Probiotic to the Diet on Productive Performance of Broiler

Following a substantial increase in poultry breeding, the demand for their meat has risen. Poultry meat is one of the primary sources of protein in human nutrition, which contributes to food security. However, implementing intensive breeding programs and exposing birds to multiple stressors have led to the overuse of antibiotics and worse poultry health. This study was carried out at the poultry farm of the Animal Production Department, College of Agriculture, University of Anbar, Ramadi, Iraq from 28/10/2021 to 8/12/2021 (42 days), to show the effect of the addition of Cordyceps sinensis extract and a probiotic to the diet of broilers on their productive performance. For this purpose, 210 one-day-old unsexed chicks of strain (Ross 308) were used with an average weight of 40 g. They were randomly divided into seven groups of treatments, and each treatment had three replicates (10 chicks per replicate). The treatments included T1, which was the control group without any addition to the diet, T2 and T3 with the addition of C. sinensis extract at a level of 300 and 600 mg/kg feed, respectively, T4 and T5 with the addition of a probiotic at the level of 3 and 6 g/kg feed, respectively, T6 with the addition of C. sinensis extract at a level of 300 mg/kg feed + the probiotic at a level of 3 g/kg feed, T7 with the addition of C. sinensis extract at a level of 600 mg/kg feed + the probiotic at a level of 3 g/kg fodder and 6 g/kg feed. The results showed a significant superiority (P≤0.05) in favor of the T6 and T7 treatments, which included the mixture of C. sinensis extract and the probiotic, in terms of the average body weight at the sixth week, over the rest of the treatments except for the T3 treatment which included the addition of C. sinensis extract at a level of 600 mg/kg feed. Regarding weight increase, the T3 treatment, which included the addition of . sinensis extract at a level of 600 mg/kg feed, was significantly superior (P≤0.05) to the T4 treatment, which included the addition of the booster at a level of 3 g/kg feed. Regarding the feed consumption rate, it was observed that all the added treatments significantly decreased it (P≤0.05), compared to the control T1 and the cumulative feed conversion factor (0-6 weeks). It was noticed that the treatments of the mixture T6 and T7 led to a significant (P≤0.05) improvement, compared to the other experimental treatments. It is concluded from this that the addition that C. sinensis extract and the probiotic improved the productive performance of broilers without any adverse effects.

Effects of the Probiotic, Lactobacillus delbrueckii subsp. bulgaricus, as a Substitute for Antibiotics on the Gastrointestinal Tract Microbiota and Metabolomics Profile of Female Growing-Finishing Pigs

Lactobacillus delbrueckii subsp. bulgaricus (LDB) is an approved feed additive on the Chinese ‘Approved Feed Additives’ list. However, the possibility of LDB as an antibiotic replacement remains unclear. Particularly, the effect of LDB on microbiota and metabolites in the gastrointestinal tract (GIT) requires further explanation. This study aimed to identify the microbiota and metabolites present in fecal samples and investigate the relationship between the microbiota and metabolites to evaluate the potential of LDB as an antibiotic replacement in pig production. A total of 42 female growing-finishing pigs were randomly allocated into the antibiotic group (basal diet + 75 mg/kg aureomycin) and LDB (basal diet + 3.0 × 109 cfu/kg LDB) groups. Fecal samples were collected on days 0 and 30. Growth performance was recorded and assessed. 16S rRNA sequencing and liquid chromatography-mass spectrometry-based non-targeted metabolomics approaches were used to analyze the differences in microbiota and metabolites. Associations between the differences were calculated using Spearman correlations with the Benjamini−Hochberg adjustment. The LDB diet had no adverse effect on feed efficiency but slightly enhanced the average daily weight gain and average daily feed intake (p > 0.05). The diet supplemented with LDB increased Lactobacillus abundance and decreased that of Prevotellaceae_NK3B31_group spp. Dietary-supplemented LDB enhanced the concentrations of pyridoxine, tyramine, D-(+)-pyroglutamic acid, hypoxanthine, putrescine and 5-hydroxyindole-3-acetic acid and decreased the lithocholic acid concentration. The Lactobacillus networks (Lactobacillus, Peptococcus, Ruminococcaceae_UCG-004, Escherichia-Shigella, acetophenone, tyramine, putrescine, N-methylisopelletierine, N1-acetylspermine) and Prevotellaceae_NK3B31_group networks (Prevotellaceae_NK3B31_group, Treponema_2, monolaurin, penciclovir, N-(5-acetamidopentyl)acetamide, glycerol 3-phosphate) were the most important in the LDB effect on pig GIT health in our study. These findings indicate that LDB may regulate GIT function through the Lactobacillus and Prevotellaceae_NK3B31_group networks. However, our results were restrained to fecal samples of female growing-finishing pigs; gender, growth stages, breeds and other factors should be considered to comprehensively assess LDB as an antibiotic replacement in pig production.

Effects of dietary bacitracin or Bacillus subtilis on the woody breast myopathy-associated gut microbiome of Eimeria spp. challenged and unchallenged broilers

Study suggested that dysbiosis of the gut microbiota may affect the etiology of woody breast (WB). In the current study, the cecal microbiota and WB in chickens fed three different diets were investigated. A total of 504 male chicks were used in a randomized complete block design with a 3 (Diet) × 2 (Challenge) factorial arrangement of treatments with 6 replicates per treatment, 6 treatments per block, and 14 birds per treatment. The experimental diets were a control diet (corn-soybean meal basal diet), an antibiotic diet (basal diet + 6.075 mg bacitracin/kg feed), and a probiotic diet (basal diet + 2.2 × 10⁸ CFU Bacillus subtilis PB6/kg feed). On d 14, birds that were assigned to the challenge treatment received a 20 × live cocci vaccine. On d 41, breast muscle hardness in live birds was palpated and grouped into normal (NB) and WB phenotypes. Cecal contents were collected and their bacterial compositions were analyzed and compared. The genomic DNA of the cecal contents was extracted and the V3 and V4 regions of 16S rRNA gene were amplified and sequenced via an Illumina MiSeq platform. There were no differences (P > 0.05) in Shannon and Chao 1 indexes between the challenges, diets, and phenotypes (NB vs. WB). However, there was a difference (P = 0.001) in the beta diversity of the samples between the challenged and nonchallenged groups. Relative bacterial abundance differed (false discovery rate, FDR < 0.05) between the challenge treatments, but there were no significant differences (FDR > 0.05) among the three diets or two phenotypes. Predicted energy metabolism, nucleotide metabolism, and amino acid and coenzyme biosynthesis activities only differed (q-value < 0.05) between challenged and nonchallenged groups. The cocci challenge altered the gut microbial composition on Butyricicoccus pullicaecorum, Sporobacter termitidis, and Subdoligranulum variabile, but the dietary antibiotic and probiotic treatments did not impact gut microbial composition. No strong association was found between WB myopathy and gut microbial composition in this study.