APPETITE AND NEOPHOBIA OF HORSES
Horses almost invariably consume only small quantities of food when it is presented for the first time (van den Berg et al., 2016). This cautious sampling of new food types is referred to as neophobia (“fear of new”) and has been suggested as an innate herbivore survival mechanism for avoiding the over-consumption of toxic plants in the wild (Provenza & Balph, 1988). While feed neophobia has been anecdotally described in horses as “fussy eaters”, similar behaviour occurs in many animal species, including humans. One test was set up in a barn to measure the effect of horses’ feeding behaviour, when offered a new type of feed, with or without certain ingredients, with 2 main measurements: 1) the preference of the animals, between the new feed and the new feed with an ingredient on top; 2) the feed intake of horses during a limited time, during the same test, to measure the acceptance of feed and evaluate solutions that might modulate it.
MEASURING PREFERENCE OF HORSES AND ITS IMPACT ON FEED CONSUMPTION
An experiment was set up with a group of horses (7 horses / all geldings / all sport horse breeds / 350 – 500 kg / 3 – 22 years old / fed with pelleted feed) to evaluate the impact of various formulations and feed ingredients. All horses were exposed with a control diet (new mash feed) (NC – negative control) and 7 tested treatments (TT) = NC + 1 new ingredient (based on supplier standard recommended dose). Every horse was proposed 2 buckets simultaneously: 1 NC vs 1 TT. Each horse was proposed the 2 buckets for 5’ with the same fixed amount of feed (200 g x 2). Besides, all horses tested the 7 treatments in a random order to neutralize any temporal effect. With this protocol, one could measure the preference and the total feed intake of PC within 5 minutes based on one double choice feeding test (NC vs PC). Preference is based on the preference of each horse, i.e. the treatment that the horse starts to eat. (ex: 60% means 60% of horse started to consume PC treatment). Feed intake was expressed in percentage of the volume of positive treatment initially given to the horse (ex: 100% means that the horse finished the whole bucket in 5 minutes).
FIRST OBSERVATIONS ON THE EVALUATION
The test was performed over 7 weeks (once per week), with new mash feed to trigger neophobia and measure the adaptation to a new feed. The average consumption and the tolerance to new feed increased a bit over time, which means horses got used to the exercise to some extent. All horses showed a similar pattern in terms of consumption, except one thoroughbred horse who behaved as a “fussy eater”. Other parameters such as age or weight were analysed but no influence was. All horses were in good shape and practised exercise regularly (no specific challenge).
IMPACT OF FEED INGREDIENTS
ON FEEDING BEHAVIOUR
Various feed ingredients and additives were evaluated in that experimentation: different flavors from various suppliers (‘fenugreek’, ‘apple’, ‘vanilla’, ‘red fruits’), one garlic extract (‘garlic’), a solution based on yeast fermentation technology (‘yeast’), and finally a new technology based on the micro-granulation of natural palatants and phytogenics (‘fresh’).
Here’s a short summary of the main observations: When offered the ‘Fresh’ treatment and the negative control (new mash feed alone), most horses preferred the ‘Fresh’ treatment. Similar results are observed for vanilla, and to some extent for the Apple and Red fruits treatments (preferred in >50% of cases). Fenugreek seemed to slightly degrade the palatability of feed, at least did not increase it. The ‘umami like’ flavour of the yeast product (yeast fermentation product) seemed to be less attractive for horses. Finally, garlic clearly reduced the palatability and attractivity of feed for horses; indeed, most horses preferred the negative control and finish it before eventually starting the garlic treatment
INFLUENCE OF FEED INGREDIENTS ON THE TOTAL FEED CONSUMPTION
Some ingredients such as fenugreek or garlic, which reduced the palatability of feed, eventually reduced the total intake as well. The yeast fermentation technology triggered an intake of 65% in 5 minutes, even though it was not proactively preferred. The apple treatment triggered an intake of 66% but the response was quite heterogeneous among horses. The red fruit and vanilla flavors seemed to trigger a quite high intake (resp. 79 and 89%), despite some heterogeneity among horses. Finally, the ‘Fresh’ treatment triggered a very high and very consistent feed intake, since most of the horses managed to eat all feed within (all animals finished 80 to 100% of the ‘Fresh’ treatment after 5 minutes)
OPTIMAL TECHNOLOGIES TO SECURE INTAKE & LIMIT NEOPHOBIA OF HORSES
Some ingredients such as garlic, fenugreek or yeast products might degrade the attractivity of feed. While these products might have a positive impact on health of animals, formulators might want to combine it with more palatable ingredients, not to degrade feed intake. Among the different treatments, some flavors such as apple or red fruits show some effect on neophobia reduction during feed transition. In parallel, vanilla seems to be a preferred option. Finally, the combination of natural palatants and essential oils, with a sweet and anise-like fresh profile and processed through unique micro-granulation technology, seems to increase the palatability but also the feed intake, with high consistency. This technology helps to optimize the attractivity of feed, the feed intake and the overall bowel function of horses.