feeding the breeding stallion Flashcards
nutrient requirements for stallions
maintenance+product
product=seamen+work of breeding and intensityxfrequency-depends on number of mounts per day
observations on breeding stallions
in one study, body weight was stable when stallions were fed at maintenance rates (=mature idle horse). In another study, stallions bw was maintained when stallions were fed at a rate similar to horses performing moderate exercise. Differences may be due to temperament, breed, turnout and level of use (AI horses used less than live cover horses)
nutrient requirements of breeding stallions
relatively small impact of semen production on nutrient needs compared to maintenance. variable breeding activity, voluntary exercise and temperament result in different nutrient needs, requirements probably range from moderate exercise (busy, alert, active stallions) to maintenance (inactive, sedentary stallions)
can nutritional supplements affect semen quality?
vitamins E/C-antioxidants that may prevent DNA damage
folate-may help with cell replication
omega-3 fatty acids-important for sperm membrane (DHA,EPA,ALA)
taurine-amino acid important for sperm production
in horses, antioxidants and omega 3 fatty acids have positive effects
positive effects of antioxidants and omega 3 fatty acids
improved 48hr motility in cooled semen, increased sperm number/motility and reduced abnormalities
but results are variable
sources of variability in supplementation results
basal diets-supplements less useful in diets that are already adequate ex. benefits of supplementing omega 3s were seen in areas where pasture was limited
length and level of supplementation, spermatogenesis takes approx. 60 days so a short period of supplementation may not help
differences among horses-most studies report that horses with poor semen characteristics improve more
obesity and fertility
results are variable, but human studies have reported alterations in sperm concentration, sperm motility, sperm morphology and sperm DNA integrity. weight probably plays a role in equine sperm too
more consistently, studies have observed decreased free and total testosterone concentration, decreased steroid hormone binding protein, decreased inhibin (hormone). Overall obesity may be a risk factor for reproductive endocrine controls
metabolic syndrome and fertility
metabolic syndrome results in increased visceral fat, insulin resistance and type II diabeties
men with metabolic syndrome have lower testosterone, lower inhibin, higher follicle stimulating hormone, lower steroid hormone binding protein, lower anti-mullerian hormone and suggested altered cell function in testes
ideal body condition for stallions
5-6 would be acceptable for most stallions, stallions that have difficulty maintaining weight during breeding season may be maintaind at a BCS of 6 during the off season. CS above 7 should be avoided due to fertility, difficulty mounting and increased laminitis risk
managing stallion body condition
most important dietary component affecting body condition is calorie content, overestimating calorie need will lead to weight gain, feeding only 2 lb of concentrate (3 Mcal/DE) above need per day for 1 year will produce 50-100 lb of weight gain
