Behavioural changes in stabled horses given nontherapeutic levels of virginiamycin.

This research focuses on the behavioral changes in stabled horses when their diet is manipulated using a feed supplement called virginiamycin. The results suggest that abnormal behaviours in horses can decrease when this supplement is used, especially in cases where the horses are fed a high concentrate diet.

Study Design and Methodology

• The study involved an experiment that was conducted over 4 weeks during which 18 horses were put on different diets. These diets ranged from hay alone to a combination of concentrate and hay in a 3:1 ratio.
• Half the horses that were given concentrate had their rations supplemented with a feed supplement called virginiamycin, marketed under the brand name Founderguard.

Findings and Results

• The study found that horses on a high concentrate diet exhibited abnormal oral behaviors more frequently than horses fed only on hay.
• However, when Founderguard was added to the diets, the abnormal behaviors significantly decreased.
• The study also discovered that Founderguard reduced the fall in faecal pH of animals on concentrate diets.
• Another observation was that animals fed on concentrate diets had on average 21 kg less gut fill during a post-mortem examination.

Implications and Conclusions

• The results of the study suggest that dietary supplementation with virginiamycin in the form of Founderguard can decrease some behavioral problems associated with the management and high-grain intake of stabled horses.
• Virginiamycin may allow for higher levels of concentrate feeding without the occurrence of adverse behavioral side-effects often encountered in stabled horses.
• The researchers believe that the reason for improved behaviour when horses are fed Founderguard is due to reduced fermentative acidosis in the hindgut of the animals.