An Investigation of the Palatability of a Novel Ingredient Fed to Horses

Palatability is defined as the physical and chemical characteristics that evoke appetite but is not well understood in the horse. Palatability is best determined during the initial feed offering. Characteristics associated with palatability trigger sensory responses by olfactory, gustatory, and tactile stimuli (Scharenberg et al., 2007). Preliminary studies have reported intake is largely influenced by odor, taste, ease of prehension, and texture (van den Berg et al., 2016). Our study was designed to investigate the enhanced palatability of horse treats containing three levels of a proprietary ingredient. Treatments were: A = 0 palatant (control); B = 1x palatant; and C = 2x palatant. Institutional Animal Care and Use approval (#16-032) was obtained prior to the initiation of this study. Ten adult horses (BCS = 5.5±0.5) receiving daily turnout and ad libitum access to water and white salt blocks were used for the study. Horses were trained to eat from identical buckets in identical stocks for 3 days prior to study. Horses were offered two buckets simultaneously (each containing 5 treats) and were allowed 10 seconds for olfactory perception and then 50 seconds for consumption. Each treatment period consisted of three consecutive days with three treatment periods total. The following variables were recorded: first action (sniff/eat), body weight, BCS, first choice, first sniff, aversive behavior, water consumption, and abnormal activity post-consumption. First sniff is defined as the first treatment sniffed during the first 10-second period; first choice is defined as the first treatment chosen after the 10-second sniff period. Categorical data were analyzed as a Chi Square using the PROC FREQ procedure of SAS while body weight was analyzed using PROC MIXED (SAS version 9.4). Body weight, BCS, and post-consumption water intake were unaffected by treatment (P > 0.05). Abnormal behaviors that were observed included hypersalivation, difficulty chewing, and excessive licking/chewing of the stall door. These data demonstrated a preference for Treatment A as compared to Treatments B and C when first choice was identified (P < 0.05). Additionally, there was pattern observed between first choice and first sniff (P < 0.01). Trained observers noted that the first consumption choice tended to mirror the bucket that was sniffed first. This may indicate that first-choice consumption is strongly affected by the first offering the horse smells. The propriety ingredient utilized in this study did not enhance palatability. Further work is needed to better understand how olfactory perception affects feed selection in horses.