Are you having trouble getting a mare in foal? Try ensuring she has constant access to forage. Recent study results suggest that broodmares appear to have better fertility levels if allowed to nibble on hay or grass continuously day and night.

In the study, conception rates were 47% higher in Arabian mares allowed to feed continuously over 23 hours, compared to those that had access to the same amount of forage but only for 17 hours a day, said Martine Hausberger, PhD, director of the Laboratory of Animal and Human Ethology, a branch of the French national research center (CNRS) and of the University of Rennes 1. Hausberger teamed up with Haifa Benhajali, PhD, of Tunis-El Manar University, in Tunis, Tunisia, for the study.

“Coming closer to the natural patterning of foraging behavior in horses may be an easy and efficient way of increasing reproduction in the domestic situation,” Hausberger said.

In the study Hausberger, Benhajali, and their fellow researchers followed 100 Arabian broodmares stabled at the Sidi Thabet National Stud near Tunis. All the horses received 10 kg (25 lbs) of hay and 4 kg (9 lbs) of barley daily. All the mares lived in individual stalls at night and had six hours of group turnout during the day. The researchers followed the mares during the breeding season, from April to mid-July. One hour each day was devoted to turning out the mares and bringing them back in.

For the experiment, half the mares received their full ration of hay in the stall, with only water and a small portion of cut grass available during turnout (the 17-hour group). The other half received half their hay ration in the stall and the other