Mixed grazing for cattle & sheep to limit parasite infestation
Aim: To limit parasit infestation
Proper pasture management can reduce the risk of parasites and the number of parasite treatments required during a production cycle. As cows and small ruminants do not share the same type of strongylosis (apart from the Trichostrongylus axei that is not considered pathogenic regardless of host), mixed cow-sheep grazing results in better control of these parasites than mono-grazing, as sheep strongle larva die when ingested by cows. Cows represents a biological dead end for sheep strongyles larvae, so by using the same plots, cows “cleanse” sheep from parasites, and sheep do the same for cows. Bear in mind that a mixed sheep-goat grazing system is not useful for regulating gastrointestinal stronylosis, as both hosts share the same type of helminth.
There are two alternatives for implementing mixed cow-sheep grazing:
- Mixing both species on the same plot or,
- Single-species grazing. This alternative results however in high ratios of both species on the same plot. A ratio close to parity in LSU is required for both species to benefit from a parasite cleansing effect. Many authors suggest the ideal ratio is one adult cow for five to six ewes
Production: Dairy / Meat
Animal Category: Adult / Replacement
Issue: Internal parasitism (e.g. Liver Fluke, Gastrointestinal, Haemonchus, Coccidiosis, Cryptosporidiosis, worms, etc.), Anthelmintic management (e.g. faecal egg count, anthelmintic resistance, grazing management)
Level of Solution: Knowledge, Practical
Country of origin: France
How to implement it
Some regions such as the Atlantic Pyrenees already use this grazing method, as both species tend to graze on different types of grasslands. Both systems require a revaluation of livestock management and installing adequate fencing on the pastures where this practice will be implemented. Currently, this process is accelerated when multidrug resistance to anthelmintics is found in sheep strongyles on the farm. Naturally, this is difficult to implement when there is only one type of production on the farm. However, implementing mixed grazing should be considered when when starting or taking over a farm.
Both methods mainly benefit sheep, as gastrointestinal strongyles infestations show a reduction in all studies and under all climatic conditions. Decrease in egg excretion are often greater than 50%, withsome studies, reporting a decrease of up to 75%. This effect is lasting, as sheep nematodes do not “adapt” to cattle. Effects of mixed grazing are mostly seen on the Haemonchus contortus found in sheep: relative abundance of this species decreases in favour of less pathogenic species. However, Haemonchus contortus is currently the most multi-resistant specie in France and in the rest of the world.
The positive effect of mixed grazing is not as apparent on cattle as it is for sheep, as the latter benefits from better lamb and replacement growth. Mixed grazing also improves vegetation cover and enables a more diverse and extensive use of the plant varieties present. Residual forage biomass is also lower if compared to mono-grazing, which is certainly due to different grazing behaviour of sheep and cattle.
Prerequisites and/or limits
Two productions systems (cows and sheep) on the same farm.
Fencing adapted to both species.
Having two production requires extra labour, but has the benefit of diversifying your source of income.