10 tips for parasite control in cattle at housing
Housing is the ideal time to safeguard cattle productivity over winter by reviewing parasite control given at grass, and treating any parasite burdens at housing.
Cattle at grass may be exposed to a range of production-limiting parasites over the grazing season. In order to prevent production losses and increased costs over winter, housing provides an opportunity to assess likely parasite burdens, and treat if necessary.
Boehringer Ingelheim Animal Health’s Ruminant Technical Manager, Sioned Timothy, gives us her tips for assessing cattle for parasites this autumn, and what to do if you need to treat them.
1. Identify the parasites on your farm
The main parasite species that cause production-loss in cattle are the gutworms Ostertagia ostertagi and Cooperia spp., the cattle lungworm Dictyocaulus viviparus, and the liver fluke Fasciola hepatica. The risk of infection at housing will vary according to local conditions, farm history, and animal treatment history. Understanding your own situation will help you to implement the most effective parasite control strategy. Ask your vet or local animal health advisor to help you test cattle and identify the types of parasite present.
2. Judge the risk of parasites to young cattle
Youngstock that have been grazing all season are highly likely to have come into contact with parasites on the pasture. Worms and liver fluke all cause production loss in young animals, making them grow more slowly, and affecting their lifetime productivity. Assessing your farm history and reviewing any treatments given at grass, can help you assess the parasite challenge faced by your cattle this year, and determine whether treatment will be necessary.
3. Assess cattle performance to identify worm and fluke burdens
The easiest method to assess growing cattle for a gutworm or liver fluke burden is to monitor their performance over time. Regularly weighing calves born during the grazing season, and youngstock after spring turnout, is a simple action that provides an invaluable insight into performance and helps ensure that growth remains on target. If animals are receiving adequate nutrition, but failing to meet growth targets worms are the most likely cause.
4. Perform diagnostic tests to help assess parasite infections in cattle
If weighing isn’t practical, ask your vet or animal health advisor to perform some diagnostic tests. Faecal egg counts (FECs) can provide an indication of the dynamics of worm infection over the grazing season, but provide a less reliable means of assessing worm burdens in individual animals, so use these with caution. An ELISA test uses blood or milk to detect antibodies to certain parasites. Lungworm and liver fluke antibodies can be detected in blood, while liver fluke and the gutworm Ostertagia ostertagi can be detected from milk samples. These tests show whether the animal has faced a parasitic challenge, but will not tell you if they are still infected. ELISA tests results should therefore be interpreted by your vet along with your treatment history.
5. Beware of winter scours in young cattle
Type 2 ostertagiosis is a severe form of parasitic gastroenteritis. It occurs when young cattle are exposed to a heavy Ostertagi ostertagi challenge late in the grazing period. These worm larvae pause their development in the wall of the animal’s abomasum. Affected cattle will be severely scouring, caused by the mass emergence of encysted worm larvae from the stomach wall in late winter and early spring. Although uncommon, this parasite disease causes significant ill-health, production loss, and can be fatal. Using a wormer that is highly effective against the encysted L4 stage of Ostertagia ostertagi at housing, will prevent this situation.
6. Reduce pasture contamination by treating cattle for parasites at housing
Treating infected cattle at housing will help reduce future pasture contamination by preventing egg output at turnout. Reducing pasture challenge is a key step in preventing early parasite infection and subsequent production loss over the grazing period. Generally, a single housing treatment is sufficient to remove worm species, but with liver fluke,
It will depend on the flukicide used and the stages present in the treated animals at housing. Cattle may require a follow-up treatment later in the winter, to ensure they are fluke-free at turnout.
7. Choose your cattle flukicide carefully to avoid selecting for fluke resistance
Emerging resistance to triclabendazole makes liver fluke treatment choice more complicated. Triclabendazole is the only flukicide that treats the early immature stage of liver fluke, which causes acute disease in sheep, but does not cause disease in cattle. At housing, an alternative flukicide can be selected for cattle, which will reduce selection for resistance and, by controlling the later stages of the parasite, reduce the impact of liver fluke on productivity. Cattle treated with products that control the late immature and adult stages of liver fluke may need to be retreated at an appropriate interval after the initial housing dose. Diagnostic testing can be used to determine whether a second treatment is necessary.
8. Consider combination treatments when treating cattle for parasites at housing
With housing a busy time, combination antiparasitic products offer a practical treatment choice and reduce the stress from handling youngstock multiple times. They allow you to treat a number of parasites with one product, including external parasites, depending on the product. They should only be used where you need to target multiple parasite species. When targeting only gutworms or only liver fluke, choose a single-action product.
9. Use correct treatment technique for effective parasite control in cattle
Correct application of wormers and flukicides is vital to ensure they work effectively, and to reduce potential selection for resistance. Always weigh each animal with a tape or weigh scale and dose to the individual weight. Assessing cattle weight by eye is not accurate and can result in under- or over-dosing. Always calibrate dosing equipment before use to check it is dispensing the correct amount of product, and ensure each dose is fully discharged. Ensure you clean your equipment thoroughly after use.
10. Monitor effectiveness of cattle worm and fluke treatments
Post-treatment FECs can help monitor the effectiveness of worm and fluke treatments on your farm. It involves collecting dung samples from 10 individual animals within a group before treatment and, according to the product used, either seven or 14 days after treatment. If the results suggest that treatment was ineffective, it should be reported to the product manufacturer and investigated further.
For advice on parasites and parasite treatments, speak to your vet or animal health advisor.