NUTRITION
Selenium in the equine diet While providing a balanced diet that meets nutritional requirements should be the main aim for horse owners, there are certain nutrients that have been discussed more by the equine community in recent years. Most significantly for New Zealand horses, selenium.
requirements of 1mg per day for
Selenium has a number of roles in
and because of this, horse owners
the body, most importantly that of
have been advised to supplement
a powerful antioxidant that helps to
accordingly. Perhaps due to the well-
counteract oxidative stress and prevent
known soil deficiency, selenium is
cell damage. Before being identified
one of the most scrutinised nutrients
as an essential nutrient, selenium was
in blood tests for New Zealand
known for its toxicity – high levels
horses. Blood selenium levels are
causing alkali disease and seleniosis.
a routine test, or when the horse is
For this reason, horse owners are wary
displaying a variety of symptoms,
of providing excessive amounts.
many of which aren’t linked to
So, what is the optimum amount to
selenium deficiencies or toxicity.
provide daily? National Research
A New Zealand study from 2016
Council states minimum selenium
showed that a group of
an average 500kg horse in work (Anonymous 2007), however Kentucky Equine Research have established an optimum requirement of between 2 and 3mg per day. New Zealand soils have long since been identified as deficient in selenium
un-supplemented horses grazing pasture in the Manawatu had blood selenium levels below the healthy range. Dr Erica Gee measured selenium monthly for one year and found that all horses in the group had average blood selenium levels of 5 – 10 times lower than normal, however all horses in the study appeared healthy throughout. While the horses in Dr Gee’s study showed low selenium levels when on pasture alone, there have been incidences of higher readings in leisure and sport horses receiving feeds and supplements which contain selenium. Observations have found that many of the horses returning high test results weren’t receiving more than 3mg of selenium per day through dietary additions. Further research is required around selenium levels in New Zealand forages, selenium blood levels of leisure and performance horses and the current blood reference ranges used to establish the reasoning behind these observations. NRM and McMillan equine formulations are constantly evolving to compliment New Zealand environments and ensure horses are being provided with correct nutrition. Horse owners are advised to consider all forages, feeds and supplements provided to their horse and consult with a qualified nutritionist to ensure a balanced diet is provided daily. Article supplied by Luisa Wood, Equine Nutritionist *Anonymous. (2007). ‘Nutrient Requirements of Horses.’ Washington DC: National Academy Press.
| Consider all forages, feeds and supplements to ensure a balanced equine diet.
WWW.FARMLANDS.CO.NZ
*Gee, E.K., Rogers, C.W. and Bolwell, C.F. 2016. ‘Selenium status of unsupplemented adult horses at pasture in the Manawatu region, New Zealand: Preliminary results’. Proceedings of the Australasian Equine Science Symposium, Volume 6.
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