Influences of Oil-Based Palatants on Eating Behavior in Gestating Mares

Gustatory and olfactory changes have been reported during gestation in multiple species. However, few data are available regarding feeding preferences in gestating mares. The objective of this research was to evaluate the effect of oil-based palatants on feeding behavior in late term gestating mares. Late-term gestating mares (n = 5) and reproductively sound, open mares (n = 4) were evaluated via paired preference testing during the final 120 days of gestation. Oil-based flavors (corn oil, anise, and apple) were topically applied to a basal pelleted diet (0.375 ml/0.23 kg). Diets were offered simultaneously using a ground level feeding platform and individual box stalls with 20 minutes allotted for engagement. Behaviors assessed included: sniffing, hovering, checking, chewing, chewing with the head lifted, uninterested, ingestion, pawing, flipping of feed pan, moving of feed platform, and defecation. Variables of interest included: first diet sniffed, consumed, and finished; time to finish first diet; time to finish all diets, and number of olfactory and consumption engagements for each diet. Data were analyzed using PROC FREQ and PROC MIXED in SAS Studio. Data analysis revealed a faster rate of consumption for first diet finished (P = .05) of gestating mares when compared to open mares. Additionally, gestating mares had a greater frequency of olfactory interactions across all diets (P < .01), but less consumption interactions across all diets (P = .01). These novel data suggest a previously unreported increase in olfactory investigation for gestating mares as well as new insights into gestational feeding behaviors of horses.