August 03, 2020

Interpretive Summary: Rotational vs. continuous grazing on horse pastures

Interpretive Summary: Effects of 27 mo of rotational vs. continuous grazing on horse and pasture condition

By: Dr. Emily Taylor

During certain months, grazing can provide horses with a sufficient source of forage while providing voluntary exercise and reducing certain behavioral and health problems. Grazing systems have been extensively researched for livestock, however, little has been done for horses. 

A recent article in Translational Animal Science evaluated the effects of rotational vs. continuous grazing on horse pasture conditions over 27 months. Specifically, the objective of this study was to determine whether rotational grazing generates horse, pasture, or cost benefits over continuous grazing systems. 

Twelve Standardbred mares were grazed for an overall stocking rate of 0.52 ha/horse while following recommended management practices for each grazing system. Three grazing seasons were included over the 27 months. 

Researchers found that the average length of grazing per rotational grazing section during the grazing season increased numerically each year, presumably as the forage roots matured. Both sward height and herbage mass were greater in the continuous pastures vs. rotational. Although the rotational pastures had a higher proportion of vegetation and total cover, planted grasses, and weeds, lower proportions of grass weeds. Forage digestibility was increased in the rotational pastures in comparison to the continuous pastures, however, crude protein was lower. 

Average horse body condition score and body fat were greater in horses on continuous grazing vs. rotational. These results may offer benefits for controlling weight and preventing deterioration of metabolic health in grazing horses; however, evaluating additional years would provide useful information to determine the long-term benefits. 

In conclusion, the effects of the grazing system on pasture conditions were significant; although, there were no differences in the supplementation of hay costs between grazing systems. The authors suggest the results support the recommendation of rotational grazing for the purposes of optimizing pasture yield as well as positive environmental and ecological purposes.