This study investigated the effects of an antimicrobial peptide (AMP), cLF36, on growth performance and the histophysiological changes of the intestine in E. coli-challenged broiler chickens. A total number of 360 day old male chicks were randomly assigned to 4 groups of 6 replicates as follows: T1) negative control diet based on corn-soybean meal without E. coli challenge and additives; T2) positive control diet based on corn-soybean meal and challenged with E. coli without any additives; T3) positive control diet challenged with E. coli and supplemented with 20 mg AMP (cLF36)/kg diet; T4) positive control diet challenged with E. coli and supplemented with 45 mg antibiotic (bacitracin methylene disalicylate)/kg diet. Results showed that T3 improved growth performance and the jejunal morphology of E. coli-challenged chickens similar to those of T4. While antibiotic non-selectively decreased the population of ileal bacteria, AMP increased the population of Lactobacillus spp. and decreased harmful bacteria in the ileum of E. coli-challenged chickens. Supplementing E. coli-challenged chickens with AMP improved the gene expression of immune cells and upregulated the expression of tight junction proteins compared to other challenged groups. In conclusion, although cLF36 beneficially affected growth performance and the intestinal morphology of E. coli-challenged chickens similar to those of the antibiotic group, this AMP drastically improved the intestinal microbiome, immune cells, and junctional proteins compared to other E. coli-challenged birds, and can be nominated as an alternative for growth promoter antibiotics.

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Despite widespread application of intracytoplasmic sperm injection (ICSI) in human-assisted reproductive techniques (ART), the efficiency of this method is still far from satisfactory in livestock, particularly in the bovine species with its unique sperm condensation. On the basis of the natural chemical structure of chromatin in condensed sperm, we developed a novel combined heparin-reduced glutathione (GSH) sperm pretreatment that improves the efficiency of bovine ICSI via selection of the most appropriate sperm at the time of ICSI. Assessment of sperm DNA integrity revealed that this pretreatment can be considered as a safe and efficient approach for in vitro sperm decondensation when compared to conventional sperm pretreatments with dithiothreitol (DTT). Injection of completely decondensed bull sperm derived from this pretreatment significantly improved fertilization and blastocyst formation rates compared to untreated or intact sperm injection (34.8 ± 2.7 and 29.1 ± 1.5 vs. 12.0 ± 3.2 and 15.9 ± 1.2%, respectively; p<0.05). Real-time PCR analysis revealed that expression of pluripotent and anti-apoptosis markers in blastocysts derived by injection of completely decondensed sperm from heparin-GSH pretreatment were comparable to IVF when compared to the DTT pretreatment and control ICSI groups (p<0.05). The results of this study suggested that the degree of sperm decondensation derived from heparin-GSH pretreatment may affect ICSI efficiency in bovine.

Clostridium perfringens -induced necrotic enteritis ( NE ) is an economically important disease of broiler chickens. The present study evaluated the effect of C. perfringens on the intestinal histomorphometry, enteric microbial colonization, and host immune responses using 3 experimental NE reproduction methods. The experimental groups consisted of 1) unchallenged Control diet (corn-soybean meal), 2) Control diet + Eimera inoculation at d 11 followed by C. perfringens challenge at d 15 ( ECp ), 3) Wheat-based diet + C. perfringens challenge ( WCp ), and 4) Wheat-based diet + Eimeria inoculation followed by C. perfringens challenge ( WECp ). The results showed that chickens receiving ECp and WECp had reduced ( P < 0.05) bird performance coupled with enteric gross lesions and epithelial damage at d 17 and 24 of age compared to unchallenged control birds. These ECp and WECp administered birds also had increased ( P < 0.05) ileal colonization by clostridia and E. coli at d 17 and 24, while the resident Lactobacillus counts were reduced ( P < 0.05) at d 24 of age. Furthermore, at d 24, jejunal transcription of IL-6, IL-10, annexin-A1 and IL-2 genes was upregulated ( P < 0.05) in the ECp group, whereas the transcription of TNF receptor associated factor (TRAF)-3 gene was increased ( P < 0.05) in WECp treated birds when compared to unchallenged control group. Additionally, stimulation of chicken splenocytes and cecal tonsilocytes with virulent C. perfringens bacilli or their secretory proteins resulted in a higher ( P < 0.05) frequency of T cells and their upregulation of MHC-II molecule, as determined by flow cytometry. These findings suggest that C. perfringens , while inducing epithelial damage and changes in microbiota, can also trigger host immune responses. Furthermore, NE reproduction methods using coccidia with or without the wheat-based dietary predisposition seem to facilitate an optimal NE reproduction in broiler chickens and thus, may provide better avenues for future C. perfringens research.

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