May 2013
Breed type and resistance: building a parasite-resistant meat goat herd at North Carolina A&T State University
by Niki Whitley and Sara Beth Routh
North Carolina A&T State University
There have been controlled research projects that show differences among meat goat breeds for many traits, including parasite resistance. In addition, some breed associations promote parasite resistance as a prominent trait for their breeds.
The Cooperative Extension Program at North Carolina Agricultural and Technical State University has a collaborative Small Ruminant Demonstration Site at the Upper Piedmont Research Station, owned by North Carolina State University. This site is designed to look at sustainable production, including integrated parasite control methods using a systems approach.
One of the integrated methods that the site will use is parasite resistant breeds and selection of breeding stock based on fecal egg counts. With this in mind, young breeding stock, mostly does of Spanish, Boer, Savanna and Kiko breeds, were collected from several different farms or genetic lines.
When animals were brought onto the farm, fecal samples were collected for fecal egg counting using the Modified McMaster technique, and animals were weighed and quarantined for at least 30 days in a parasite-unfriendly environment.
The Modified McMaster’s fecal egg counting technique is a simple procedure that farmers can learn to do themselves. Most veterinarians and diagnostic labs could also perform fecal egg counts for a fee.
Although we collected samples at least monthly after arrival, we will only give information for the initial (on-farm) fecal egg counts, weights, and ages for this article. Only data from animals less than one year of age is used here (see table).
The Spanish does were from various bloodlines, including Valera, Smoke Ridge, Baylis, and Pape. Their on-farm fecal egg counts ranged from 0 to 1,400 eggs per gram (epg).
The Boer (94-100%) and Boer crossbred (75-88%) does were all from the same farm, one that has used artificial insemination for at least the past four years. Several sire lines were represented in the does. The range in fecal egg counts was 34 to 1,473 epg for the Boer does and 200 to 1,700 epg for the crossbred Boer does.
The Savanna (100%) and Savanna crossbred (50-75%) does were obtained from five farms in four different states, though a large number were from one farm. On-farm fecal egg counts ranged from 200 to 8,625 epg for the Savanna and 0 to 2,850 epg for the Savanna crossbreds (crossed primarily with Boer).
There were not as many Kiko (100%) or Kiko crossbred (50-88%) does less than one year of age. On-farm fecal egg counts ranged from 500 to 800 for the Kiko does and 350 to 4,450 for the Kiko crossbreds (crossed primarily with Boer).
Prior deworming protocols were not known for most of the farms, and most of the animals had multiple drug (dewormer) resistant worms based on lack of reduction after multiple drug combined treatment. Multiple drug resistance was confirmed on at last two farms by DrenchRite® testing.
The Boer goats were managed for lower fecal egg counts and had been kept indoors in a parasite-unfriendly environment for at least three weeks prior to shipment, which could explain lower egg count levels since the seller indicated they have had parasite problems on the farm.
Although some believe that the Savanna goat is parasite resistant, currently there is no data to support this claim. At our small ruminant demonstration site, we plan to document the resistance or susceptibility of various breeds and crossbreeds; however, the data reported in the table are for information purposes only and are not indicative of resistance or susceptibility of any breed or cross.
Fecal egg counts can be impacted by many things and this initial data is just the beginning of the work planned, though Spanish and Savanna only will be focus at this site.