A Whole Farm (Organic) Approach to Parasite Management
Author: Karen Nicholson
Internal parasites are a part of most every livestock producers farm. Regardless of whether they are pasture raised or in a confinement setting, livestock will be exposed to internal parasites at some time in their life. In the Northeast, and in other humid climates, parasites can be a major problem for small ruminants, such as alpacas, sheep and goats.
So why adopt an organic approach to parasite management? Chemical dewormers are losing their effectiveness, with parasites developing resistance to them at an alarming rate. There are some parts of the country where internal parasites have developed resistance to all commercially available dewormers without new ones being developed. In our area where Meningeal worm is a threat and there is widespread use of Ivermectin, parasites that were formerly managed with this drug have grown resistant to it. Resistance means that not all the worms are killed during deworming. The surviving worms pass that genetic resistance on to offspring.
The growing concern about the resistance of internal parasites to all classes of dewormers has caused people to look for alternatives. By looking at the whole farm as an interrelated system, it becomes apparent that there are parts of the system that can be managed to decrease internal parasites and their effects. This management whole farm approach not only postpones the day when chemical dewormers no longer work, but it also increases the overall health of the individual animal (and future herd), and it may even decrease costs.
It All Starts with Prevention and Management:
1. Healthy, properly conditioned animals Nutrition plays a major role in how well alpacas are able to overcome the effects of internal parasites. Quality feed, fresh water, minerals, managing stress and monitoring for condition are essential. Check weights/body score and mucus membranes and observe the herd regularly to monitor condition.
2. Stocking Density - By maintaining a healthy stocking density you decrease the overall infectivity rate of the farm. It also allows you to have more areas (pastures, etc) that you can rest for longer, creating more clean areas. To calculate the optimum stocking density youll find a good worksheet at www.sarahflackconsulting.com
3. Quarantine When an animal comes or returns to the farm keep it with a buddy in a quarantine area for one month while monitoring their health and doing regular fecals. This can protect your herd (particularly the geriatric, cria, weak or pregnant/lactating females) from parasite overloads and other disease.
4. Pasture Rotation - There could be an entire article alone on this subject. If we begin with an understanding of the interrelationship between the animal, the plants it eats and the soil on which those plants grow, then it will become clearer how parasites infect the animal and how they can be managed so as not to cause as many problems. Narrowing it down to two subjects there is: rotation for the health of the grasses and soils and, rotation to work with the lifecycle of parasites.
A. Lifecycle of parasites Although some parasite eggs can live in the soils year round without a host, many of the parasites we are dealing with go through up to a 21 day lifecycle outside the host. The infected manure is dropped, three days later the eggs hatch into larvae searching for a host (the alpaca) and most die by 21 days if a host does not ingest them. Consider wildlife where parasite loads generally do not cause disease and death in the host because, instinctively, wildlife are on the move. The parasites have no host if the animal is no longer where the manure (eggs/occysts) was dropped. The same principle applies to livestock. If we rotate our animals every 2-3 days to new pastures and do not put them back on that same pasture for a minimum of 21 days we are significantly decreasing the numbers of larvae available to be ingested. Ideally, you want to size your pastures so that they eat it down to not less than 2 in 3 days (or even better 12-24 hours) as most larvae live in the bottom 1-2 of grass.
B. Health of Grasses and Soils Healthy soil grows healthy plants. Healthy plants provide good nutrition to animals. Unhealthy soils also have fewer of the beneficial organisms (dung beetles, earthworms, nematophasous fungi, etc) which can kill parasites. Chemical dewormers also kill most of these organisms that are working for you. Test, monitor and fertilize your soils as necessary. Grasses - overgrazing (below 2) damages pastures as the alpaca will continue to graze the most vigorous and productive plants in the pasture down very short which will stress the root system of the plant, in turn reducing the productivity of that pasture. If this happens every year for several years in a row it can greatly reduce the amount, quality and the diversity of plants the pasture will produce. Overgrazing also cuts down on the animals efficiency and dry matter intake resulting in poor performance.
5. Cleanliness Keep clean barns and pastures. Scoop manure twice daily or as often as is practical and pile it in the current active compost pile. Actively composting your manure by creating the proper carbon/nitrogen mix will heat up the manure to 135 degrees and kill most pathogens. Removing manure often keeps the alpacas from stepping in it and dragging it all over and ingesting larvae. Larvae migrate from the manure up to 12 inches.
6. Animal Selection - Select breeding males that exhibit parasite resilience. Resilience is the ability of the host (alpaca) to maintain health during a parasite challenge. In most livestock production, resilience is one of several traits that are being selected for. By monitoring and keeping good records we can most often detect which animals almost never shed eggs regardless of the parasite load of the rest of the herd. Typically, 10-20% of animals will always be heavily parasitized, 10-20% will be lightly and 60-80% will fall in between. Identify these genetic lines and selecting for them in our breeding will improve the health of our herd and the future herd. For example: dont put sires into production from sires/dams that either always have parasite problems themselves or always produce crias that have parasite problems. An example of an effective parasite control program can be found in TN. Dennis Onks of Highland Rim Experiment Station has not dewormed the adult cattle on the farm in eight years. They are dewormed at weaning and not again. They have never shown any signs of internal parasites and their condition is excellent. These animals are on a high plane of nutrition, have a low stress level and are strictly culled on production. Producers who add parasite susceptibility to their list of selection criteria find that in 2-3 years they have greatly decreased the incidence of parasite problems in their herds.
7. Encouraging Hardiness Too much of a good thing can actually work against the animal. Ideally, you want an animal that can retain health when faced with adversity.
8. Other Grazing multiple species together or rotating them behind one another can be helpful as they are a dead-end host for each others parasites. Chickens and ducks will also consume some of the parasites. Consider planting herbal lays (weedy pastures) and high tannin forages for improved gut function.
Then moves to Monitoring and Treatment . . .
1. Fecal Monitoring Testing and monitoring animals is crucial to determining the progress and success of your parasite management program and in determining which animals are resilient and which are not. The ultimate goal is for the animal to develop immunity or resilience to parasites, NOT to be parasite free.
A. Observation is one method identify which animals always keep condition, have firm beans, etc. regardless of stress or the performance of the rest of the herd.
B. Fecal Testing is another method of monitoring and aids in identifying which animals are resilient and which always carry heavier loads. Sometimes it can identify a problem much more quickly than observation. Once parasites have been identified in a fecal test they can be monitored by additional tests for increased/decreased loads significantly reducing the number of deworming treatments. Consider doing fecal testing on-farm as it can get expensive.
2. Strategic Deworming Treatment should be the last resort that includes alternative and pharmaceutical treatments. Careful fecal monitoring instead of conventional seasonal or routine deworming should increase resilience and decrease parasite resistance to the drugs. Treat the individual animal not the whole herd. Proper dosing is also important. If you do not knock out the parasite but only knock it down you are encouraging adaptation and resistance to the drug. If your vet doesnt specialize in alpaca care make sure he/she is up to date on proper treatment and dosages. Put crias in a pasture with low level parasites to give them low dose exposure so that they can develop immunity. Transition animals slowly from winter hay feed to pastures to not upset the gut and to slowly introduce the animal to pasture parasites that survived the winter. Give probiotics at times of stress, immune challenge, immunizations, and gut challenge. Do not move animals to new pasture until 12-24 hours after deworming to allow enough time for parasites to be killed and eggs to be expelled.
Summary Parasite overloads are a symptom that there is sickness within the farm. It is disease in individual animals but also an indication of imbalance or a problem on the farm. While implementing all strategies can seem overwhelming, slow changes can make dramatic improvements in parasite levels and the overall performance of the herd. If we were to choose the most effective methods they might be: Prevention good nutrition is essential, grazing management and selecting resilient dams/sires to improve crias. Early Observation catch symptoms of disease or ill thrift early thru routine observation of the herd. Trust your gut instinct. Use fecal monitoring as a preventative and monitoring tool. Treatment as the option of last resort but certainly when the animals health requires it.
Please note: The information shared in this article should be approved by your veterinarian before being utilized in any way on any individual farm.