The Influence of Topically Applied Oil–Based Palatants on Eating Behavior in Horses

Impacts of olfactory cues on equine feeding behavior

Anise has demonstrated equine palatability but its olfactory effect is underexplored. The objective was to investigate the effect of the aroma of anise on consumptive behavior. Stock-type horses (n = 8) were used in a crossover 6-day preference test. Palatability stocks were utilized. Bowls containing oats were situated on plates holding gauze soaked with 0.375 ml of anise or corn oil (control). Variables included first diet sniffed (FS), first consumed (FC), first action (FA), and amount consumed (AC). Each trial was video-recorded. Behavior data were analyzed using chi square and Kruskal-Wallis tests. FS and FC were elevated for anise treatment (P = 0.02; P = 0.04). For FA, sniffing was more frequent versus consuming (P < 0.01). AC for anise was twice the daily average of control (P < 0.01). Data represents an important relationship between olfactory stimuli and feeding in horses. To determine thresholds, more work is needed.

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 = 0.05) of gestating mares when compared to open mares. Additionally, gestating mares had a greater frequency of olfactory interactions across all diets (P < 0.01), but less consumption interactions across all diets (P = 0.01). 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.

Horses’ Response to a Novel Diet: Different Herbs Added to Dry, Wet or Wet-Sweetened Oats

Simple Summary

The commercial horse feed industry uses palatants to mask undesirable tastes of feed and enhance consumption. However, an unknown smell or taste may also hinder feed intake, due to, among other aspects, novelty. The acceptability of herbs by horses has not been studied. We analysed whether five herbs (field mint, common yarrow, common chamomile, common sage and common nettle) added alternately to oats and presented within a dry, wet or wet-sweetened diet influence horses’ willingness to consume. Twenty horses were given different diet combinations of a feed presentation and a herb consecutively, once daily. Seven parameters showing the willingness to consume were measured: times of olfaction and consumption, times and numbers of intervals in consumption and drinking water, and mass of leftovers. The results show that the herbs in the amount offered did not influence the time of intake and only the dry oats with common sage added were smelled longer before consuming. However, wetting or wetting and sweetening the feed increased the willingness to eat. In conclusion, herbs in small amounts do not affect the feed intake, whereas wetting and sweetening the diet is of great importance and should be regarded when preparing horse diets.

Abstract

The commercial horse feed industry uses palatants to mask undesirable tastes of feeds and enhance product acceptance. However, an unknown odour or taste may also hinder feed intake, due to, inter alia, novelty. The objective of the study was to assess the horses’ response to novel diet: five different herbs added alternately to dry, wet or wet-sweetened oats. Twenty adult horses were given different diet combinations of a feed presentation and a herb: field mint, common yarrow, common chamomile, common sage and common nettle, consecutively, once daily. The response to novelty was assessed regarding traits showing the willingness to consume: times of olfaction and consumption, times and numbers of intervals in consumption and drinking water, and the mass of leftovers. The results show that properties of the herbs studied did not hinder the consumption and only the odour of the dry common sage delayed the intake. Wetting or wetting and sweetening the diet accelerated the intake. In conclusion, herbs in small amounts do not significantly affect the willingness to consume feed. Although wet and wet-sweetened diet presentations may be novel to horses, they increase the feed palatability and can be suggested for use when preparing horse diets.

Feed Concentrate Palatability in Welsh Ponies: Acceptance and Preference of Flavors

In horses, it is well established that nutrients and the palatability of feed material (odor and taste) play an important role in diet selection. For example, high-fiber feed taste is not well accepted by horses. Consequently, manufacturers have begun to supplement horse feed with flavors to mask feed bitterness, to overcome feed neophobia and to encourage water drinking. However, only few studies have been performed to evaluate the acceptance and preference of flavors in horses. The aim of this study was to evaluate the acceptance and preference of flavors supplemented on top of concentrate offered to ponies. Thirty-three female Welsh ponies aged between four to 13 years were enrolled in the experiment. Ponies were offered 4 flavored concentrates and one control with no flavor. The flavored concentrates were anise, caramel, raspberry and apple. The inclusion rate of the flavors was 300 g/t on an as-is basis. During the adaptation period (one week), the ponies were gently guided to each bucket containing the flavored concentrate (200 g) during 10 sec/bucket for olfaction only. During the test period, ponies were allowed to freely choose flavored concentrates for 2 minutes. The flavors and the position of the buckets in front of the ponies were randomized. Each period was video-recorded and number of chews were counted during test period. The concentrate intake, eating time, and animal behavior were recorded during the test period. The apple concentrate was consumed the most at 116 g/2-min offering, whereas the raspberry and control concentrates were consumed the least, at 85.31 and 90.80 g/2-min offering, respectively. Apple flavor was preferred over caramel, raspberry and anise as indicated by higher consumption rate (g/sec) (chi-squared=16.68, df=4, P<0.05). There was no effects on chews, smell or headshaking time per sec between treatments. In conclusion, the ponies accepted a wide range of flavors with a preference for apple over raspberry flavored concentrate.