September 2006
Featured Articles

Managing Parasites During Drought Conditions

by Robert Spencer

As experienced by many livestock producers this past summer, drought situations occur from time to time and should not be forgotten without taking time to reflect on learning experiences. As farm manager, it is important to understand the relationship between drought conditions and livestock vulnerability to parasite infestation.

During drought conditions, pasture growth tends to be minimal, yet animals must continue grazing until most forages are often eaten down to the ground. As a result of this type of situation, many goat producers experienced health problems within their herd during the summer of 2006.

During droughts situations, availability of forages becomes limited, goats (and livestock in general) graze grasses down to dirt level where they are likely to ingest high numbers of parasites. Both worms and coccidia live on the ground. When grasses are wet with morning dew, worms tend to climb up blades of grass and weeds to a maximum height of about six inches. I don’t know why the maximum height for the worm to climb tends to be about six inches, but that is what observations have shown. My theory is anything above six inches and the worms begin to suffer from altitude sickness (just kidding). Goats come along, take bites of grass, and then end up ingesting grass with worms included. This is the process whereby goats easily become infested with parasitic worms.

After a goat has ingested worms, the worms get cozy inside the warm, moist stomach and then lay eggs that hatch into more worms. As the worm population increases inside the goat’s stomach, the overall health of the goat diminishes as the worms literally suck most of the red blood cells out of blood vessels found lining a goat’s stomach. This tends to result in anemia, whose visual symptoms include pale mucous membranes and, when severe, a condition known as "bottle jaw."

 
  You can tell a healthy goat by its smile.
Bottle jaw can be recognized by a swollen, puffy area under the jaw of a goat. The condition is caused when fluids resulting from anemia and protein loss accumulate under the jaw of a ruminant (goat, sheep or cow).  Completely eliminating the presence of worms is almost impossible, but proper management practices tend to be effective in minimizing the number present.

Coccidia are a parasitic micro-organism found in and on the ground. Coccidiosis is treatable, but scours must be controlled before the goat dehydrates. Otherwise, you may lose the goat long before intestinal damage from coccidia occurs. Coccidiosis becomes obvious when the host animal develops diarrhea, more commonly known as scours. The existence of small amounts of coccidia inside a goat is normal; totally eliminating coccidia is almost impossible. Only when the numbers flourish does a problem exist.

Coping with drought conditions tends to call for tough management practices. As mentioned earlier, short forages and close grazing conditions allow goats to pick up parasites. Grasses should be at least six to eight inches tall; this minimizes the opportunity for goats to pick up worms and coccidia. There are numerous practices (if your situation allows) that may or may not be practical; rotational grazing and intensive rotational grazing are two such practices. Rotational grazing requires additional fencing and possibly additional buildings for each pasture. As goats graze grasses short (near six to eight inches in height), a farmer must decide when to move animals onto more lush pasture.

As weather and pasture conditions vary from year to year, stocking rates must vary accordingly. Lush pasture conditions more readily accommodate heavy stocking rates, while sparse rainfall and limited availability of forages require lower than normal stocking rates. If minimal stocking rates are not an option, then supplemental hay and feed will become necessary as pasture conditions deteriorate.

Learn when to deworm and how to manage worms and coccidia. There are times when the worm burden on individual or groups of animals becomes a problem and the animals need to be dewormed. Choice of dewormers will vary from farm to farm and manager to manager. A working relationship with a veterinarian and/or animal scientist will benefit a producer when making a decision on effective deworming practices.

Use of hydrated lime (agriculture lime) on pastures once a year (fall of the year) will improve pasture conditions and possibly help control parasite populations. Dusting the barn and loafing areas where the goats spend their leisure time will help minimize problems with parasites, including lice. Applying fertilizer during late spring and early summer will promote grass growth, and provides more forages; but with the cost of fertilizer these days, soil testing is essential to minimize expenditures on unnecessary nutrient application.

Culling is a nasty word for some livestock producers, but extreme conditions call for extreme measures. Determining which animals to cull from one’s herd is not a pleasant task but does allow the opportunity to sell some animals which may not fit into a farm management plan. Culling during extreme weather conditions is a common practice for most livestock producers. However, as the number of animals reaching sale barns increases, sale prices generally drop, minimizing monies farmers receive; but less money per animal is a better option than mortality among animals whose health is compromised as a result of drought conditions.

Another option is to dry lot your parasite infested animals until they recover. This requires a fenced area that is free of grass and dirt. Instead, the ground is covered with concrete, gravel, mixed wood shavings or straw. In the absence of grass and dirt, worms and coccidia cannot survive. However, the cost associated with establishing such a containment area can be prohibitive when trying to accommodate a large number of sick goats.

Understanding situations resulting from drought conditions and how to effectively manage parasites should result in a more effective management program. Severe droughts require stringent initiatives that might not set well with a producer; but watching animals suffer is even worse. Managing pasture conditions, herd health and stocking rates are several practices that can be implemented to minimize opportunities for parasite infestation.

Robert Spencer is the Urban Regional Extension Specialist in the Urban Affairs and New Nontraditional Programs Unit & The Urban Centers in North Alabama for the Alabama Cooperative Extension System.