EFFECT OF CATTLE AND HORSE FECES STORAGE METHODS ON NEMATODE EGG VIABILITY AND SENSITIVITY FOR EGG HATCH TEST.

The research study aimed to establish the best methods of storing fecal samples for testing. For bovine samples, the results indicated that storage could be up to 96 hours in refrigerated vacuum conditions. However, equine samples were found to be more sensitive to storage methods, hence no concrete solution was offered in this regard.

Objective of the Research

• The main goal of this study was to validate the most effective and reliable method of fecal sample preservation intended for the egg hatch test (EHT).
• The focus of the EHT was predominantly Cooperia spp. in bovine samples and cyathostomins in equine samples, both of which have been identified to hold susceptibility to benzimidazoles.

Methodology

• Fecal samples underwent three types of treatments, namely anaerobic storage in plastic bottles, anaerobic storage in vacuum-sealed bags, and aerobic storage in plastic bags.
• These treatments were then subjected to two different temperature conditions, room temperature and refrigeration.
• Each of these combinations evaluated at four distinct timeframes, after 48, 72, 96, and 120 hours.
• As a control group, a test was also carried out within three hours.
• All tests were replicated three times for each drug concentration, with a week’s gap between repetitions.

Criteria for Evaluation

• Two parameters guided the judgment of the storage methods: the hatchability in the negative control group and the sensitivity of the eggs to thiabendazole, a medicine used to treat parasites.
• These were gauged by comparing the EC50 and a 95% confidence interval for each treatment with the standard test results, and other repetitions.

Findings and Final Remarks

• The findings suggested that bovine samples could be stored for up to 96 hours using vacuum storage under refrigeration, ensuring a good level of hatchability and suitable egg sensitivity to the drug thiabendazole.
• On the contrary, for equine samples, none of the storage methods turned out to be promising due to inconsistencies in repetitions and a significant reduction in egg sensitivity to thiabendazole, which could result in a false positive detection of resistance.