Effect of alfalfa chaff versus alfalfa pellets in weanlings

The aim of this study was to investigate the effects of feeding two alfalfa preparations with different particle sizes (alfalfa chaff vs alfalfa pellets) in comparison with grass hay on the gastric mucosa in weanling horses. They hypothesized that feeding a high proportion of fine particles (alfalfa pellets) would negatively impact gastric mucosa in foals and that foals receiving alfalfa chaff would have better gastric mucosal lesion scores.

Before weaning, the gastroscopic findings of each region did not differ significantly between the three diet groups. After weaning, gastric mucosal lesions at the pylorus were significantly more severe in the group fed alfalfa chaff. In the other regions, no differences related to the feeding regimes were observed.

Foals fed alfalfa chaff had higher ulcer scores at the pylorus than those fed alfalfa pellets or hay. These results were surprising because alfalfa chaff has been suggested to be associated with higher saliva production due to the more intensive chewing involved; increased saliva flow is known to have a buffering effect on the stomach.

They speculated that the pyloric ulcers might be related to the small particles of the alfalfa chaff. It is possible that the harsh acanthous structure of alfalfa chaff may cause mechanical injury at the pylorus. The pyloric region is an area of the stomach with high motility. They assume that the movement of the alfalfa stems may excoriate the mucosa during passage.