Latrine behavior in pasture vs large areas of land
Horses not only affect their environment though grazing behavior, they play a unique role in developing an ecological niche. They fertilize pastures via defecation and can modify soil structure by trampling. In doing so, they alter the ecology of the area. As such, management of manure and grazing can provide significant challenges for many horse owners. When horses and ponies are in vast areas such as rangeland and the stocking densities are low, there is a reduced pressure to select grazing vs latrine areas. Horses in this setting are often found performing eliminative behaviors in and around grazing areas. Horses are free to use an area of land and move on to the next. However, in a more restricted pasture setting, they typically do not eat where they defecate. They select certain grasses for consumption, tending to heavily graze these areas of a pasture creating patches of overgrazed “lawns” or “nutritive areas”. Horses tend to localize regions of pasture in which they relieve themselves of manure and urine away from these lawns. These regions are left under grazed, yielding tall and overly mature forage and resulting in the name “roughs” or “eliminative areas”. Thus, manure and forage management is critical in pasture settings.
Managing pasture to eliminate lawns and roughs
Development of lawns and roughs in a pasture setting is not only unsightly, but is also an inefficient use of grazable land. Several management strategies may be used to overcome this problem.
- Use a sacrifice lot. A challenge with pasture grazing is that areas can become overgrazed. This weakens the plant root system and creates opportunities for undesirable plants to move in and take over, such as invasive weeds. Establishment of a home-base, where horses can be kept from time to time, such as when pastures need a rest from grazing, is a great management strategy. This area is called a sacrifice lot because this space is compromised in order to maintain the rest of the pasture in a healthy and productive state. Horses should be moved to the sacrifice lot when pastures have been grazed and need a period for recovery. Horses should also be relocated to sacrifice areas when pastures are wet and easily trampled, including during and after rain. Horses that are housed in sacrifice lots without access to pasture should have access to hay.
- Implement a rotational grazing system. Not everyone has access to unlimited grazing acres. Yet, even on small acreages, pasture use can be maximized with the use of a rotational grazing system. This is accomplished by partitioning a large pasture into smaller pastures. Horses are permitted to graze one small pasture until half of the forage height has been utilized and then are moved to the next small pasture. This method of rotating horses from one pasture to the next promotes more even grazing since they do not have the opportunity to over graze certain areas. Another benefit is that pastures are provided a rest period, during which forage regrowth occurs.
- Mow the pasture. Early growth forage is not only more palatable, but also carries a higher nutritive value for horses than mature, stemmy forages. Mowing the pasture will create the opportunity for a more even growth of all plant species within a pasture. An additional benefit of mowing is that the growing point of weeds is often higher above ground level than forages; so mowing helps minimize weeds in a pasture.
- Rake the pasture. Harrowing or raking fields to distribute manure piles is an additional management strategy to help promote more even grazing within a pasture. When manure piles are spread, the material breaks down faster and results in more even fertilization of the pasture. Spreading manure also minimizes the ability of horses to designate eliminative areas, thus promoting more uniform grazing. Special consideration should be given to horses in any confined pasture setting.
There are several management strategies to ensure the health of horses and pastures. For further information on the strategies presented in this article, or for information on the establishment of pastures in South Dakota, view Equine Pasture Maintenance & Renovation for South Dakota.
- Bott RC, Greene E, Koch K, Martinson K, Siciliano P, Williams C, Burk A, Trottier N, Swinker A. Environmental Impacts of Grazing Horses: A Review. J. Equine Veterinary Science. 2013 Vol 33, Issue 12, Pages 697-704.
- Lamoot I, Callebabaut J, Degezelle T, Demeulenaere E, Laquiere J, Vandenberghe C, et al. Eliminative behavior of free-ranging horses: do they show latrine behavior or do they defecate where they graze? Appl Animal Behav Sci. 2004 Vol 86, Pages 105-21.
- Odberg FO, Francis-Smith K. A study on eliminiative and grazing behavior-the use of the field by captive horses. Equine Vet J. 1976 Vol 8, Pages 147-9.