Parasite-free pastures, healthy cattle

It is no secret that in order to have a healthy herd of Angus cattle we need to provide it with a proper development environment. The genetic baggage that our animals carry can only be enhanced by a harmonious growth in which water, food, rest and movement are ensured to the highest standards. In summer, these desiderata can be fulfilled relatively easily letting the flocks graze in an environment where the animals feel best. However, grazing risks becoming dangerous when carried out on areas contaminated with parasites, thus cancelling the farmer’s efforts to maintain healthy cattle, with appropriate daily weight gain and no health problems.

How is pasture contaminated? Pastures can be contaminated by helminth-bearing animals, other favourable factors being the density of the animals per unit area and the structure of the soil. Sandy soils are more conducive to the development and maintenance of parasitic elements than compact and clay soils. Moisture also plays an important role in the development of intermediate hosts, eggs and larvae. Climatic factors positively influence the sterilization of pastures in winter, and in spring and summer, they favour the development of eggs, larvae and intermediate hosts.

The biology of each parasite is conditioned by these factors and, thus, they contribute to a dynamic of pasture infestation with various parasitic elements during a calendar year. Even if the pasture is sterilized during the winter, it can be contaminated again with parasitic elements from the parasite-bearing animals, regardless of the degree of parasite infestation. The intensity of the parasite infestation increases in spring, decreases during summer and increases again in autumn.

This is explained by the fact that parasitic elements are sensitive to high temperatures and low humidity. It is worth remembering that the pastures or fodder also carry different cestode oncospheres, that can produce cenurosis or echinococcosis that have as their final host dogs, and cysticercosis, that occurs in cattle and produces tapeworm in humans; cattle contamination occurs by eating fodder and in especially in pastures. Thus the following parasitosis or intestinal worm infections can endanger cattle grazing on pastures: fasciolosis, paraamphistomosis, dichrocelliosis, monesiosis, dictyocaulosis, strongyloses and strongyloidoses.

The most important factors that contaminate pastures are the larvae of various helminths, eggs or cysts of coccidia, a chain that also includes a series of invertebrates that are intermediate hosts for the development of parasitic forms with one or more stages; so it turns out that the main contaminating animals of the pastures are cattle which are untreated on time and dogs, their companions on pasture.

Even if in theory things are complicated and quite difficult to understand, we must be aware that the best way to rid our herds of cattle from the problems caused by parasites is prevention. Thus, we can take some concrete steps in the fight against parasites:

1. Carrying out copro-parasitological examinations of animals in the herd to identify existing parasitic species. We will be able to use the most suitable antiparasitic products for our animals.
2. Preparation of the animals by systematic deworming of the whole herd 30 days before grazing in spring. In this way, antiparasitic products will have time to act and the animals will not contaminate the soil with parasites.
3. Preparation of pastures by rehabilitating muddy places and treating pastures with chemicals for the destruction of intermediate hosts. The place for the prophylactic dehelmitization in a pasture will be established in compliance with the norms of the legislation in force.
4. The pastures will be cleaned; well fermented and sterilized fertilizers and the necessary chemical fertilizers will be applied on them, respecting the rotation of the fields, and a rational grazing program of the animals will be drawn up.
5. Last but not least, a second deworming of the whole herd is welcome in autumn, with increased attention to the area where the animals will stay later (pasture or stable) to avoid re-infection of animals with parasitic forms eliminated through manure and re-arrived in the ground.