Prevention of Worms in Goats by Management Techniques
This article contains information on how to decrease worming your goats with de-wormer by means of improved herd, pasture management and feeding practices. Gastrointestinal mamatodes, commonly known as worms, present the greatest danger to the goat industry. Haemonchus contortus, commonly referred to as the barber pole worm is a clinical problem for goats. Infested goats have a lower growth rates, markedly reduced reproductive performance and higher rates of illness and death.
There are a number of factors that contribute to barber pole worm infestation in goats:
Signs of barber pole worm infestation in goats:
Preventative measures through improved herd, pasture management and feeding practices
Reduce your herd: goats are often restricted to small pastures where the number of parasite larvea can build up to dramatic numbers leading to frequent drug treatments leading to resistance.
Take a hay crop, plow or reseed: This type of pasture can be incorporated into a dose and move program, in which goats are grazed on one pasture in the early season than deworm any goat showing signs of worms (using FAMACHA system) and moved to another pasture which was used for the first cutting of hay. Another move before the end of the grazing season will probably provide the best parasite control.
Graze contaminated pastures with another species: Cows, horses or donkeys will work well. When another animal species eats the goat parasite larvae, the parasite will be killed. Sheep or young calves will not work as they both carry barber pole worms. Most studies indicate greater production and better pasture utilization are acheived when cattle and goats are grazed together. This is especially true where a diverse plant population exisist. because of complimentary grazing habits, one or two goats can be grazed with every beef cow, without adversely affecting the feed supply of the beef herd. The selective grazing habits of the goats in combination with cattle will eventually produce pastures which are more productive, of higher quality and with little weed and brush problems. Mixed species grazing can have additional benefits. because gastrointestal parasites from goats cannot survive in the stomach of cattle, mixed species grazing will decrease the gastrointestinal parasite loads and slow resistance to conventional dewormers. Several strategies can be used-in fields with low parasite loads, animals with the highest nutritional requirements can have access to field first (dam with kids). Alternatively, in field infested with high parasite loads, cattle should be grazed first, followed by goats.
Pasture Rotation: The main reason to use pasture rotation is to provide the most nutritious forage for growth and development. Reducing infectousness can be achieved by cutting pasture for hay between grazing periods.
There is evidence that part of the variation in host resistance worm infection is under genetic control in goats. Resistance is most likely based on inheritance of genes which play a primary role in expression of host immunity. Based on the survival of the fittest management conditions. Using resistant breed crossbreeding programs would certainly lead to improved resistance to worm infection, but some level of production would be sacrificed. While such stategy may be acceptable to some, selection for resistant animals within the breed is also a viable option. Within breed, animals become more resistant to infection. However, some animals within such population do not respond very well and remain susceptible to disease. This means that the majority of the worm population resides in the minority of the animals. It would make sense in culling these "minority parasitized" animals, those retaining more resistant stock. Keeping monthly records using the FAMACHA system will make this process easier. Finding a herd sire that throws relatively resistant offspring, would speed up this process. This process may take a while but we found significant improvement in as little as two years.
An easy-to-use pasasite-control program for identifying Haemonchus contortus (worms) in small ruminants. The FAMACHA syste, is an eye chart showing varying degrees of anemia as indicated by the color of the lower eyelid. We use three color system:
The FAMACHA system allows producers to seperate infested goats for treatment or culling; rather than worming the entire herd. Other goats are dewormed less frequenly, which slows the development of resistance.