Written by: Dr. Andrea Ellis
The 9th European Workshop in Equine Nutrition took place at SLU in Uppsala, Sweden from the 16-18th August 2018. Here are a few highlights of what’s being discussed and presented in the professional equine research and nutrition world.
Session I – Nutrition and Behaviour
1. The first session focused on behaviour and nutrition and started with a very interesting plenary lecture by Prof. Helgi Schioth from the Swedish University of Agricultural Sciences, who came from the direction of human medicine and focused on what we know about the link between temperament, aggression and mood changes in humans in relation nutrition. In human high sugar and starch meals have now been implicated in being ‘addictive’ through the dopamine pathways, leading to aggression and depression during fasting/withdrawal of these foodstuffs. Prof Schioth highlighted the strong palatability and flavour effect in relation to this in humans. Feed intake in horses is regulated via similar pathways and this may explain the extreme aggressive behaviour seen around concentrate feeding times.
My take away message and tip: Horses never evolved to eat distinct meals of high palatability. Constant access to forage feed and ideally various types of forages to provide variety and allow for choice helps to avoid rapid mood swings while keeping interest in feed.
Tip: Why not put layers of two types of forages into your Forager Slow Feeder bin? Ensure of course that you have acclimatised your horse slowly to another forage first by introducing no more than a kilogram (2 pounds) initially and slowly building this up over 2 weeks.
2. Dr Andrea Ellis from Unequi Ltd, presented the collaborative Masters work of Pam Bennet-Skinner, University of Edinburgh, focusing on the effect of haynets and the pressure needed to pull hay from these as well as the head-neck position in horses. Haynets are used to keep hay off the floor and to slow down feed intake behaviour. The average pressure exerted under the experimental conditions described here (fairly short cut hay with little resistance) was equivalent to 5-8kg for a single haynet and 8-10kg for a double haynet with small hole sizes (3cm2). More pressure was exerted on lower hanging haynets. Some extreme head-neck angles were recorded when horses lifted the haynet up while pulling and the nose was seen to be above the withers up to 10 times per minute.
My take away message: The majority of hay was pulled out fairly easily but having longer, late cut hay may increase the pressure. The high lifting of the neck and head could be avoided if the haynets are also tied down at the bottom, rather than if they lift off the wall because only attached at the top. Feeding from the ground or a ground trough is most natural and will avoid these extreme angles.
3. Maria Wilhelmsson presented a poster from her Masters Research, University of Edinburgh, which highlighted that show jumpers in training continued to work and compete effectively when moved from a 40% concentrate : 60% forage diet to a 15% concentrate diet with 85% forage of higher quality and quantity. The change also re-established a much more natural feeding pattern.
My take away message: To all owners of performance horses – there is enough evidence out there now to show that horses can perform well on a high forage diet. Consult with an independent nutritionist and make the changes for your horses! At best it will reduce occurrence of ulcers and colic and at worst it may well increase longevity and give you a more mentally balanced horse.
4. During another forage feeding study, Phillippa Tuthill from the Royal Agricultural University, UK, fed one group of TB foals a traditional concentrate/forage ration that the stud has always fed, whereas the other group of foals were fed a total forage based ration, consisting of some Soya, Linseed and high quality haylage. The foals on the total mixed ration showed equal growth rates, but managed to avoid the ‘sudden dip’ in bodyweight seen in the high concentrate foals after weaning, and were scored as being generally calmer.
My take away message: Both the show jumpers and the foals’ study underline the ability of horses to maintain performance and growth when fed on mainly high forage diets, if balanced and of good quality. Interestingly in both studies the owners returned to the original diets in order to save money once the ‘free supply’ of the novel forage-based feed from the study ran out. Is it then so, that many professional owners are too short-sighted at times to see the long-term potential of saving money through prevention of health issues, even if the feed bill is a little higher initially?
5. Two posters by Sveinn Ragnarsson from Holar University College, Iceland, highlighted that horses will not self-regulate quantities of mineral licks or salt licks, eating considerably more when they are given free access, especially when restricted forage is fed. Owners should only allow restricted access to these as overconsumption can have detrimental health effects.
My tip: By weighing a mineral bar or box-lick, the amount ingested per day can be easily calculated and this should be done on a weekly basis. Divide the weight that has disappeared since the last weighing by 7 to get a daily intake rate and compare this to the recommended amount on the package. If your horse has taken an ‘unhealthy’ liking to the lick, it may be better to supplement the diet with specific amounts or restrict access.
6. Linda Kjelberg, from the Swedish National Equestrian Centre, presented a study highlighting that Warmblood riding school horses living in an open yard feeding system with feeding stations will visit the stations numerous times throughout the day and that forage intake rates vary considerably between and within horses. We later had the opportunity to see the open yard system for ourselves.
7. Malin Connysson also worked on this evaluating the free-range housing system in comparison to box housing. Her team found that horses recovered faster from a race-like exercise test when kept on the free-range group housing system.
The free-range Group Housing System at the Swedish National Equestrian Centre, Stromsholm: Top Left shows the Forage Feeding Station and top right the area which contains shelters as well as the feeding stations. The lower picture highlights the entrance to the concentrate feeding station. Horses can walk in but only if they have not yet eaten their daily allowance for that half of the day will they receive a feed ration. The collar they wear around their neck has a microchip through which the feed computer recognises each horse.
References: All from: Proceedings of the 9th European Workshop on Equine Nutrition, Uppsala 2018, Sweden
- Professor Helgi Schiöth: Why is feeding causing aggression frustration in horses and can diet affect temperament and mood? Uppsala University, Sweden
- Pam Bennet-Skinner, Andrea D. Ellis and Pat Harris : Measuring neck angels and the pressure horses exert when pulling hay from haynets
- Maria Wilhelmsson, Malin Olson, Ingrid Vervuert, Bryony Lancaster and Andrea D. Ellis: Observations on digestive and ingestive parameters in 6 performance horses when moved from a traditional high concentrate diet to a high forage diet – A field study
- Phillippa Tuthill, Meriel Moore-Colyer and Simon Daniels: The effect of a concentrate based diet or a total mixed fibre ration on growth rates in Thoroughbred foals
- Sveinn Ragnarsson, Sibriour Guobjartsdottier and Anna Jansson: Voluntary salt consumption in stabled Icelandic horses
- Sveinn Ragnarsson, Sibriour Guobjartsdottier and Anna Jansson: Voluntary sweet mineral lick consumption in stabled Icelandic horses
- Linda Kjellberg and Karin Morgan: Measurement of Horses’ Feeding Rate in Automatic Roughage Stations
- Malin Connysson, Marie Rhodir and Anna Jansson: Housing system affects feed intake, body weight and recovery of energy balance