Internal Parasites and Immunity in Ruminant Cattle: How to Strike a Lasting Balance?

The fact that ruminants live in coexistence with parasites is normal as parasites naturally belong to their environment. The balance between a host and its parasites reflects the actual opposition between a herd and its parasitic environment. Paradoxically, the upkeep of this relationship is indispensable to the optimal expression of these animals' performance. Disrupting this balance could lead, at best, to decreasing the efficiency of the diet, and at worst, to mortalities. The application of a sustainable approach can help to establish an effective immunity. It also results in shaping an environment that becomes hostile to parasites. This seems easy in theory, yet how can we implement it in practice?

Appetite and weight loss, intestinal disorders... Parasitic infestations in cattle, goats and sheep can lead to serious issues in the event that parasites proliferate. The obvious signs of their invasion range from a mere drop in production to the appearance of genuine pathological diseases. As an example, growth losses in cattle fluctuate between 80-150 g of average daily gain (ADG) for young adults; their daily milk production can drop from 0.5 to 2 litres of milk.

Where shall we begin? First, we will attempt to support animal immunity, by activating a positive immune response in the animal’s body. This relates to the natural defense mechanisms that ruminants deploy against internal parasites in their environment. The success of this action will depend on the upkeep of continuous contact with the parasite at a moderate level, and by the supply of a balanced diet. Remember that we must intervene at the right time in the parasite’s life cycle. Indeed, animal immunity takes several months to build up. It eventually results in the production of specific antibodies against the parasites at stake.

Maintaining a good balance between the host and the parasite can help to reduce performance drops in ruminants. Reducing the risk rather than treating the source of disease better fits in what is termed a ‘sustainable approach’; this method is actually a lot more profitable than the first option.
Here are a few guidelines for achieving this goal:

• at the nutritional level, we must ensure that the diet is well balanced, especially regarding the variations caused by the long grazing periods (copper, magnesium ...);
• at the grazing level: rotational grazing and restricted access to water meadows contribute to limiting the levels of infestation;
• at the environmental level: an environment that hinders the development of the parasite cycle becomes hostile to the parasite.

Farmers must constantly adjust their methods to anticipate the worst risky periods. Some nutritional products have been specially designed to support animals' immunity in these trying periods. If these are administered in a timely manner, they can contribute to limiting performance declines. They can also help to reduce the risks of resistance development and immunity breaks in the event of anthelmintic treatment.

If you want to tailor your strategies regarding parasite risk management by stimulating the natural defenses of your animals, our experts are here to help you; please do not hesitate to consult them!