SPILLERS was the only UK feed company to have research presented at the 2017 Equine Science Society (ESS) Symposium, a leading scientific conference held in the US. Five scientific studies conducted in collaboration with the WALTHAM Equine Studies Group were presented and we wanted to share the key take home messages with you. With research relating to body condition scoring, vitamin E, digestibility and the diagnosis of insulin dysregulation, we hope there is something for everyone…
Study 1: Reliability of the Combined Glucose/ Insulin Test in native ponies
Scientific Title: Repeatability of the combined glucose/ insulin test in ponies of the same breed and gender, across time.
The combined glucose/ insulin test (CGIT) is recommended for the diagnosis of insulin dysregulation. However it is unknown whether the current reference values which were defined in horses are reliable in ponies. As a result, CGIT’s were completed in 6 Welsh Mountain Ponies on 4 separate occasions.
Our take home message: The high degree of variability within individuals highlights a need to redefine the cut of values used for diagnosing insulin dysregulation in native ponies. This supports our other research that also suggests that ponies need to have different threshold values for other important diagnostic tests such as the Oral Sugar Test.
Study 2: Relationship between body condition score & other assessments of body composition
Scientific Title: Relationship between total body water, ultrasonic measures of fat depots and morphometric measurements in horses
Body condition scoring is the most common assessment of body composition used by horse owners but other methods have also been used. This study explored the relationship between body condition score (BCS), fat depth measured by ultrasound, total body water (TBW – which provides an estimate of total body fat as we have previously confirmed in ponies), weight and several ‘morphometric’ measurements such as heart girth, height and belly girth in horses and found: An increase in TBW was related to a decrease in BCS
- As fat around the tailhead (assessed by ultrasound) increased, TBW decreased and BCS increased
- BCS was related to weight, belly girth: height ratio, heart girth: height ratio, heart girth: bodyweight ratio, and belly girth: bodyweight ratio.
Our take home message: These results suggest that a number of additional measurements could be used to strengthen the assessment of fat coverage made by body condition scoring, the accuracy of which may vary between assessors.
Study 3: Feed digestibility in different breeds
Scientific Title: Digestibility of different diets after a weight gain protocol in Standardbreds, Andalusians and mixed-breed ponies
Ponies and some breeds of horses tend to gain weight easily and are often referred to as ‘good doers’. However it is not yet known whether increased digestive efficiency is responsible for this. In this study Standardbred horses, Andalusian horses and mixed breed ponies were either fed for maintenance (hay, balancer, chaff and soya hulls) or fed for weight gain using the same hay but either a ‘high fat’ or ‘high cereal’ diet providing around double their maintenance requirements at the end of the 20 week study.
Our take home message: Although nutrient digestibility was affected by the type of diet, breed had no significant effect. This suggests that differences in digestibility may not be a major factor in the tendency for some breeds to gain weight more easily than others.
Study 4: Natural vs. synthetic vitamin E for exercising horses
Scientific Title: Assessment of oxidative stress and muscle damage in exercising horses in response to level and form of vitamin E
Vitamin E is an important antioxidant that works to combat damage caused by free radicals – potentially damaging substances which are produced as a result of any bodily process which uses oxygen. Vitamin E is typically abundant in fresh green forage but due to increased work and often limited access to grazing, performance horses may have to rely even more on supplemental sources. The aim of this study was to assess whether (1) feeding vitamin E above published requirements is beneficial and (2) the effect of feeding natural vs. synthetic vitamin E. Eighteen horses were divided into 3 diets groups; 1. Synthetic vitamin E fed at the published requirement 2. Synthetic vitamin E fed at 4 times the published requirement and 3. Natural vitamin E fed at 4 times the published requirement. All horses completed an exercise before and after completion of the same 6-week exercise programme.
Our take home message: The preliminary results reported suggest no negative effects of feeding high levels of vitamin E as monitored in this study and some potential beneficial effects especially of the natural form of Vitamin E
Study 5: Age & Nutrient Digestibility
Scientific Title: Comparison of nutrient digestibility between three diets for aged and adult horses
In this study 8 healthy adult horses (5-12 years) and 9 healthy aged horses (19-28 years) were fed either hay only, hay plus a sugar and starch based feed or hay plus a fibre and oil (fat) based feed. Energy, protein, NDF (fibre) and mineral digestibility was measured using feed, urine and faecal analysis.
Our take home message: Age did not significantly affect any of the parameters measured suggesting that in healthy horses, an increase in age does result in decreased digestion. However protein and mineral digestion was lower in the hay only diet regardless of age, highlighting the importance of feeding a balancer even in horses that are retired/ at rest.
- Morrison PK, Dugdale AHA Grove-white DH Harris PA Barfoot CF & Mcg Argo C (2017) Repeatability of the combined Glucose/insulin test in ponies of the same breed and gender, across time Journal of Equine Veterinary Science, 52, p57
- Fowler AL Pyles MB Bill VT Hayes SH Crum A Parsons J Walling L Moffet- Krotky A Harris PA Laurence L (2017) Relationships between total body water, ultrasonic measures of fat depots and morphometric measurements in horses Journal of Equine Veterinary Science, Vol. 52, p50–51
- Potter SJ Bamford NJ Harris PA & Bailey SR Digestibility of different diets after a weight gain protocol in Standardbreds, Andalusians, and mixed-breed ponies Journal of Equine Veterinary Science, Vol. 52, p85–86
- Fagan MM Pazdro R Call JA Abrams A Harris P Krotky AD & Duberstein KJ (2017) Assessment of oxidative stress and muscle damage in exercising horses in response to level and form of vitamin Journal of Equine Veterinary Science, Vol. 52, p80–81
- Elzinga S Nielsen BD Schott HC Prapson J Robison CI Mc Cutcheon J Geor R Harris PA (207) Comparison of nutrient digestibility between three diets for aged and adult horses DOI: Journal of Equine Veterinary Science, 52, p89