Weigh youngstock regularly. As parasites reduce liveweight gain, regularly weighing cattle and intervening when growth is lower than expected ensures that parasites do not cause excessive production loss.
Prevent cattle from accessing high risk pasture such as that which is constantly grazed by cattle, where grass has been grazed very short, beside rivers and streams, boggy land, or where manure has not been effectively composted. This is especially important for out-wintered cattle.
Vaccination before turnout provides rapid-onset immunity against lungworm. It is a useful option, especially for young cattle during their first year at grass, and for all cattle on farms with a known lungworm population.
Some parasite infections will require urgent veterinary care. Be alert to the early signs of lungworm and severe parasitic gastroenteritis, especially in youngstock. If left untreated or treatment is delayed, these infections may prove fatal.
Making a parasite control plan, as part of an annual herd health review, can help you stay on top of monitoring and treatments, to prevent reductions in performance. Make an annual appointment with your local animal medicines advisor (SQP) or your Vet.
Identify your best performing animals (those that are regularly meeting or exceeding their liveweight gain targets) and leave this group of individual animals untreated against parasites. This encourages refugia within the herd and reduces the likelihood of selecting for anthelmintic resistance. Alternatively, rotate between non-treated animals and treated animals on the same plot.
Proper diagnosis is crucial to making sound decisions about parasite control strategies. Diagnostic techniques vary by parasite and animal age, but in general they identify parasite presence and/or indicate relative level of infection at either an individual animal or herd level. This is a critical indicator of potential impact on an animal or herd and is vital information for making the decision as to which treatment protocol to implement.
Using 'safe grazing' for youngstock from mid-June means that they experience a lower worm challenge. This may reduce the need to use anthelmintics. Safe pastures are ones that have not been grazed by sheep or cattle in the previous year, and those that have been cut for silage or hay.
Rotating pasture regularly allows grass to recover and regrow. This is important since 80 percent of parasites are concentrated in the first 5cm of grass, so cattle are more likely to ingest parasites if grass is eaten down to the extreme. Strip grazing is an option if rotating whole paddocks is not feasible, but cattle should be moved on once pasture becomes bare.
Reduce the stocking density of animals on pasture. This will mean animals don't need to feed near faecal pats and will thereby decrease the risk of ingesting parasites emerging from the dung.
To preserve anthelmintic-sensitive parasites in the population, cattle should not be wormed before moving to clean pasture. If worming is deemed necessary through diagnostic testing or growth monitoring, then one approach is to leave a proportion of the best performing animals untreated.
Your local SQP/RAMA is a qualified animal medicines adviser and can help you to decide which anthelmintic is the best for your cattle, at the right time of year. Speak to them when you are next in your local agriculture merchant to find out more
Housing cattle, either wholly or for part of the year (e.g. over winter) prevents them from acquiring new parasite infections from pasture. Over wintering provides a good opportunity to treat parasite infections picked up during the grazing season, and ensure they are turned out free of parasites in the spring. This reduces the egg output onto grass at turnout, and helps to reduce infectivity risk in the spring and early summer.
Prevent the creation of high risk environments that are ideal for the mud snail, the intermediate host of the liver fluke, and thereby reduce the risk of liver fluke infection. Re-site water sources such as troughs to hard standing, to prevent poaching. Equally, do not allow cattle to use natural water sources such as streams, rivers or ponds.