The Impact of Nuisance Flies on rumen and respiratory microbiome in growing dairy Heifers

The horn fly is an economically important external parasite of cows and horses. Cows with large numbers of flies on them have lower milk production and decreased feed conversion due to avoidance activity. In this study, two groups of Holstein-Friesian heifers were observed for their level of horn fly infestation. The pedigrees and microbiomes of the cows with the five highest and five lowest levels of fly infestation were compared.