The Effect of Management Strategies on Haemonchus Contortus Infections of Sheep and Goats on Intensively Grazed Pasture

The purpose of this study was to determine how the management strategies used by producers on sheep and goat farms in Maine, New Hampshire, and Vermont could affect the fecal egg counts of the parasite called Haemonchus contortus in their animals. Surveys about management practices and fecal samples from the juvenile and adult populations were collected during the months of June, July, and August in the summer of 2015. Next, the samples were analyzed and fecal egg counts were determined using the McMaster method and a fluorescence-based H. contortus speciation technique. The fecal egg counts and survey answers were compiled and Analysis of Variance tests were used to determine significance between groups. The results of this study suggest that particular management practices are more effective than others at controlling the proliferation of H. contortus on farms. Specifically, the use of chemical dewormers rather than natural dewormers led to lower fecal egg counts (P=0.078). In addition, farms with larger numbers of animals tended to have lower fecal egg counts (P=0.091). Other factors, such as the use of FAMACHA scores for the replacement of animals or the geographic locations of the farms did not prove to have a significant effect (P=0.75 and 0.97, respectively). The results of this study can be used to teach producers about realistic ways to control H. contortus in their flocks and lead to healthier, more productive populations