horses . Foals at risk for hock osteochondrosis ( OCD ) are heavier at 15 days and 8 months of age . Those at risk for stifle OCD are heavier at 25 days and 4 months of age . Studies on the growth and body composition of Quarter Horse foals found height increased by 25cm but fat thickness only by 0.6cm between birth and weaning . The mares milk provides the nutrients the foal needs until it is 2 to 3 months old . Foals do not need to have access to the mares feed before this age due to the risk of higher body weight gains and fat deposition .
PG . 45
PERFORMANCE HORSES Fat covers the horse ’ s body like a blanket , similar to a blubber layer in seals and walruses – and fat on the outside is matched by fat on the inside . This makes it extra hard to get rid of body heat . An overheated or dehydrated horse won ’ t perform well and can get into serious trouble with heat stroke / stress . Fatter horses are carting around a weight handicap - one BCS = around 17kg ! This is also a disadvantage in competition , slowing the horse down , making it harder for jumpers to get off the ground , for dressage horses to achieve suspension and for barrel horses to execute tight turns . Joints , tendons and ligaments are under heavy strain
laminitis . Fat cells are capable of producing hormones that promote insulin resistance and obesity is a cause as well as an effect of insulin resistance .
PREGNANT MARES : Insulin resistance is a normal part of pregnancy and occurs at around 28 weeks gestation . The mare becomes insulin resistant so blood glucose can be diverted to the growing foal . Fatter mares are more insulin resistant than normal mares by late gestation . A diet high in sugar and starch exacerbates the insulin resistance of pregnancy and increases the risk of hoof problems and sub-clinical and clinical laminitis in pregnant mares . Feeding a diet rich in fibre and fat allows for adaptation of glucose metabolism to pregnancy and lactation .
Mares that are overweight at the time of insemination have foals with more osteochondrosis lesions from birth to 18 months of age . Although there is no difference in birth weight or subsequent growth , insulin resistance is greater in foals at 6 and 18 months of age . By 18 months of age , 30 % foals of obese mares had OCD lesions , compared to 10 % of foals from normal mares .
Broodmares that are too forward in condition are more likely to ‘ run milk ’ before foaling – reducing the supply of protective colostrum to the newborn foal . If there is significant milk loss ( constant and considerable dripping and streaming of milk ) the vital first milk ( colostrum ) will be lost before the foal can ingest it . This alone could be life-threatening to the foal ( failure of passive transfer ).
FOALS AND WEANLINGS Gains in height and body weight are linked to bone and joint problems in young
MANAGING BODY WEIGHT
1 . Reduce sugars in the horse ’ s diet - remove molassesbased feeds , grains and grain by-products ( including extruded and pelleted feeds that contain bran , pollard , millrun etc ). Beet pulp is a good feed for horses needing extra energy for work or lactation . It has as much energy as grains but doesn ’ t affect blood insulin . Don ’ t feed grain to horses that don ’ t need it , and if they do need grain , feed it after exercise , not early in the morning . For the overweight horse , grain is absolutely not needed .
2 . Feed frequent small meals - this mimicks natural grazing and doesn ’ t result in dramatic and damaging spikes in blood glucose and insulin that occur when fewer , larger meals are served .
3 . Restrict grazing – pasture can be really high in sugar . Levels rise through the day reaching maximum levels at sundown . The safest time for grazing is between 3am and midday . Grazing muzzles , strip grazing or mixed grazing with sheep or cattle are other ways to reduce horses sugar intake from grass . Some horses may not be able to have any pasture until their insulin levels are regulated .
See www . jenquine . com / laminitis for more information and tips on grazing .
4 . Maintain mineral and protein intakes . Microminerals such as copper , manganese , zinc , selenium and iodine are essential to metabolism , provide a complete and balanced supplement that meets the horse ’ s minimum requirements . Ensuring an adequate source of quality protein is important to preserve muscle mass during weight loss .
AQHA MARCH / APRIL ISSUE 2022