Insight View on the Role of in Ovo Feeding of Clenbuterol on Hatched Chicks: Hatchability, Growth Efficiency, Serum Metabolic Profile, Muscle, and Lipid-Related Markers

The present study aimed to assess the in ovo administration of clenbuterol on chick fertility, growth performance, muscle growth, myogenic gene expression, fatty acid, amino acid profile, intestinal morphology, and hepatic lipid-related gene expressions. In this study, 750 healthy fertile eggs from the local chicken breed Dokki-4 strain were analyzed. Fertile eggs were randomly divided into five experimental groups (150 eggs/3 replicates for each group). On day 14 of incubation, in addition to the control group, four other groups were established where 0.5 mL of worm saline (30 °C) was injected into the second group of eggs. In the third, fourth, and fifth groups, 0.5 mL of worm saline (30 °C), 0.9% of NaCl, and 10, 15, and 20 ppm of clenbuterol were injected into the eggs. Results suggested that clenbuterol increased growth efficiency up to 12 weeks of age, especially at 15 ppm, followed by 10 ppm, decreased abdominal body fat mass, and improved hatchability (p < 0.01). Clenbuterol also modulated saturated fatty acid levels in the breast muscles and improved essential amino acids when administered at 10 and 15 ppm. Additionally, clenbuterol at 15 ppm significantly decreased myostatin gene expression (p < 0.01) and considerably increased IGF1r and IGF-binding protein (IGFBP) expression. Clenbuterol administration led to a significant upregulation of hepatic PPARα, growth hormone receptor, and Lipoprotein lipase (LPL) mRNA expression with a marked decrease in fatty acid synthase (FAS) and sterol regulatory element-binding protein 1 (SREBP-1c) expression. In conclusion, the current study revealed that in ovo injection of clenbuterol showed positive effects on the growth of hatched chicks through reduced abdominal fat deposition, improved intestinal morphology, and modulation of hepatic gene expressions in myogenesis, lipogenesis, and lipolysis

Evaluation of Bifidobacteria and Lactobacillus Probiotics as Alternative Therapy for Salmonella typhimurium Infection in Broiler Chickens

Chicken Salmonella enterica serovars are enteric bacteria associated with massive public health risks and economic losses. There is a widespread antimicrobial resistance among S. enterica serotypes, and innovative solutions to antibiotic resistance are needed. We aimed to use probiotics to reduce antibiotic resistance and identify the major probiotic players that modify the early interactions between S. enterica and host cells. One-day-old cobb broiler chicks were challenged with S. typhimurium after oral inoculation with different probiotic strains for 3 days. The adherence of different probiotic strains to Caco-2 intestinal epithelial cells was studied in vitro. Lactobacillus (Lacticaseibacillus) casei ATTC334 and Bifidobacterium breve JCM1192 strains attached to Caco-2 cells stronger than B. infantis BL2416. L. casei ATTC334 and B. breve JCM1192 reduced S. typhimurium recovery from the cecal tonsils by competitive exclusion mechanism. Although B. infantis BL2416 bound poorly to Caco-2 epithelial cells, it reduced S. typhimurium recovery and increased IFN-γ and TNF-α production. L. casei ATTC334, B. breve JCM1192 and B. infantis BL2416 improved body weight gain and the food conversion rate in S. typhimurium-infected broilers. B. longum Ncc2785 neither attached to epithelial cells nor induced IFN-γ and TNF-α release and consequently did not prevent S. typhimurium colonization in broiler chickens. In conclusion, probiotics prevented the intestinal colonization of S. typhimurium in infected chickens by competitive exclusion or cytokine production mechanisms