Few studies have been conducted showing the effects of changing the physical form of long-stemmed hay. A trial by Gagnon and Barbisan comparing long-stemmed hay and cubed hay on water intake showed that the horses fed a cubed ration consumed more water than those fed a long-stemmed hay ration.
Form and function of hay in horses
A comparison study between long-stemmed hay and complete cubed ration on water intake, fecal moisture and out-put in horses was conducted using eight geldings at Montana State University.
Because of inconsistencies in previous study results, a comparison between long-stemmed hay and complete cubed ration on water intake, fecal moisture and out put was conducted using eight geldings at Montana State University in Bozeman.
This trial was designed to compare water intake, fecal moisture, and fecal output between long-stemmed hay and cubed hay rations in horses.
Producers have often hypothesized that water intake is greater for horses consuming cubed rations than horses fed long-stemmed hay rations. Pagan and Jackson showed that horses excrete and drink more water on long-stemmed hay rations than on pelleted rations.
Coenen and Meyer also found that horses on roughage diets have a higher fecal output of water than horses fed a more concentrated diet, and there is a higher water content in the gut of horses fed long-stemmed hay and is due to increased endogenous secretions and/or lower absorption rates.
The mean results of the Bozeman study indicate that horses on complete cubed rations refused less of their rations than horses on long-stemmed hay rations. Water intake of horses on long-stemmed hay ration was significantly greater than those on complete cubed ration. Fecal moisture of long-stemmed hay ration was greater than complete cubed ration. There was no significant difference in total fecal output between the rations.
Intake of feed by horses is always a concern for horse owners. This trial showed that horses refused significantly more feed when fed long stemmed hay than when fed cubed rations. This difference is probably due to the wastage by horses on the long-stemmed hay rations in this study.
This trial also suggests that fecal moisture is higher for horses on long-stemmed hay than cubed rations and is consistent with those suggested by Pagan and Jackson (1991). Coenen and Meyer (1987) reported observing that as particle size of the feed swallowed increases, fecal moisture increases.
In addition, this trial suggests dry matter output is greater for cubed hay rations than long-stemmed rations. Previous trials conducted suggested dry matter output to be the same for both cubed rations and long-stemmed rations.
The difference shown in this trial is probably due to the significant amount of refusals or wastage by horses on long-stemmed hay rations. However horses became more efficient as the trial progressed suggesting that feeding excess rations influences wastage and intake.
All horses in the study that were fed long-stemmed hay had higher fecal water content then those fed cubed hay, resulting from the higher water intake on long-stemmed hay than the cubed hay. The health and condition of all the horses remained excellent during the trial. There were no horses that required special treatment or veterinary care.