Domestic poultry is a natural reservoir of Campylobacter, the host–pathogen interaction being predominantly asymptomatic. This study investigated whether chickens remain asymptomatic partly because of lactic acid bacteria (LAB).

Carvacrol is an essential oil derived from oregano that is used as a natural additive to improve the efficiency of livestock nutrition. Residues of natural additives such as carvacrol should be monitored in food of animal origin to ensure consumer safety. The aim of this study was to appraise the quick, easy, cheap, effective, rugged and safe (QuEChERS) approach coupled with liquid chromatography and mass spectrometry as a means of carvacrol analysis in chicken tissue. A 5 ± 0.05 g portion of plasma, lung, muscle and liver was mixed for 15 min with 5 mL of 1-butanol and 20 mL of water, then centrifuged. A 0.5 mL volume from the top layer was transferred, then 60 mg of octadecylsilane sorbent, 30 mg of primary and secondary amine and 200 mg of MgSO₄ were added. The extract was mixed and centrifuged. The top layer was filtered and then transferred to an autosampler vial for analysis by high-performance liquid chromatography–tandem mass spectrometry. The limit of detection was calculated at 0.06 μg g⁻¹ and the limit of quantification was 0.2 μg g⁻¹, with relative standard deviation repeatability and reproducibility below <20%. The validation results showed that this method could be a good alternative to determination of carvacrol by gas chromatography and is suitable for carvacrol analysis in different matrices.

Domestic poultry is a natural reservoir of Campylobacter, the host–pathogen interaction being predominantly asymptomatic. This study investigated whether chickens remain asymptomatic partly because of lactic acid bacteria (LAB). Campylobacter spp. and LAB were isolated from the gut of poultry chickens using enrichment and screening assays and were identified via rDNA sequencing. The C. jejuni DC3 isolate was grown in different cell-free supernatants (CFS) generated from a priority LAB isolate. An in vivo challenge involving the C. jejuni and LAB isolates using a chicken model was performed to confirm the in vitro findings. Twelve presumptive LAB isolates had anti-C. jejuni activity based on cross-streak and agar plug assays, with Lactobacillus sakei L14 isolate exhibiting the highest activity. Inhibition by L. sakei L14 CFS of the growth of C. jejuni occurred in a dose-dependent manner. Campylobacter jejuni DC3 inhibition was most evident in CFS harvested at 72 h and produced by co-culture with the pathogen. Neutralisation of the CFS abrogated the observed inhibition. Co-infection with C. jejuni DC3 and L. sakei L14 in vivo, however, failed to inhibit C. jejuni colonisation in chickens. The results suggest that the anti-C. jejuni effect of L. sakei L14 in chickens may be due to mechanisms other than direct inhibition of growth.

Objective: The current broiler trial was planned to assess the effects of Kolin Plus™, a polyherbal formulation (PHF), on performance, protein and fat accretion, and serum L-carnitine (LC) levels in broilers fed a high-energy diet (HED). Materials and Methods: A total of 500 1-day-old Cobb 430 male chicks were assigned to 5 treat¬ment groups consisting of 10 replicates, with 10 birds in each replicate (n = 100). Group G1 was a negative control fed HED, and group G2, a positive control supplemented with synthetic choline chloride (SCC) 1,500 gm/ton in HED. Groups G3, G4, and G5 were supplemented with PHF in HED at 400, 500, and 750 gm/ton feed, respectively (PHF400, PHF500, and PHF750). Results: The PHF produced a dose-dependent numerical improvement in body weight, feed con¬version ratio, livability, and the European Production Index. There were no changes in carcass nitrogen and protein accretion, whereas a statistically significant decrease (p < 0.05) in carcass fat and fat accretion was observed in the SCC and PHF groups. Moreover, PHF showed a significant increase in serum LC levels. Conclusion: Kolin Plus™ improves performance parameters akin to SCC by improving fat metabo¬lism and mobilization by enhancing serum LC levels and restoring normal fat accretion. [J Adv Vet Anim Res 2022; 9(1.000): 166-174]