(T2) Lecture 9a - Lifecycle nutrition of horses Flashcards
What is the estrous cycle influenced by?
- photoperiod
- nutrition
- physiological condition
- environmental temperature
What is reason for seasonal polyestrous?
- most forage available in spring and summer
- seasonal effect of food being available in excess and short supply; also tied to photoperiod
- want foal to be born when more food is available
How to nutritionally manage good estrous?
body condition score
Body Condition Scoring
Poor: 1-3
Moderate: 4-6
Fat: 7-9
What is an example of how to score a horse’s body condition?
Based on 6 body sites
Cresty Neck Score: you can use the neck for scoring body condition in a horse
What is very important during gestation?
Body Condition Score
Optimum BCS during estrous cycle =
- increase fertility
- increase milk yield
- increase health
- shorter follicular phase in estrous = increase cycles
- shorter winter anestrous
How does a low BCS affect the estrous cycle?
longer anestrous
- decreased hormone levels
Homeorhesis vs Homeostasis
Homeorhesis: controlled change
Homeostasis: controlled lack of change
What is the ideal gain during gestation?
Gain 12-15% above normal BW
5 energy requirements to consider during pregnancy
- maintenance of dam
- deposition of fetal and placental tissue
- hypertrophy of the uterus
- mammary development
- maintenance of 2, 3, 4
Why do pregnant mares have added maintenance requirements?
Because the additional tissues grown are very metabolically active
What are the DE requirements for pregnancy if the mare is at a normal BCS?
Met by DEm for first 5 months, then increases gradually each month
- later into gestation, there is a gradual increase in energy requirement needed to support the mare and fetus
If additional energy is not supplied to pregnant mares with ideal BCS, what can happen?
- delayed estrous
- reduced conception
- embryonic death
What happens to protein requirements between pregnancy at 5 months to parturition?
Addition for fetal gain and non-fetal tissue needs
How are mineral and vitamin requirements affected by pregnancy?
Increased requirements during late gestation
- for vitamin A and E its a “safety factor”
What happens with feed during parturition?
- reduce feed intake 24 hrs before birth
- good quality hay, low-energy cereal - after parturition, energy and protein needs must be met
- first bran mash, secondly cereal and protein - restrict concentrate (aka starch and sugars) feeding to 10 days postpartum
- avoid excess milk secretion and Gi disturbances in foal
What is milk yield influenced by?
- feed consumption during late gestation
- feed quality
- water availability
- nutrient and energy intake
- interaction btw mare and foal(s)
What would be a consequence of decreased milk production?
malnutrition of the foal
Protein requirements for lactation
- sensitive to quality
- elevated CP requirement + milk production
Calcium requirements for lactaion
- Increased demand
- if you see an increase in PTH = not getting enough Ca
What are some factors that would increase energy requirements of stallions?
Increased activity
5 physical signs of aging in horses
- chronically low BCS
- loss of muscle mass
- “sway” backed appearance
- gray coat
- dental disease
2 general considerations of aged horses
- Large metabolic changes
- Dental abnormalities are common
- alter physical form of ration to increase digestibility
- feed haylage or chopped hay
- soak hay or hay cubes in water
- supplement oil to increase energy density
Why is MER typically lower in older animals?
less activity
Why is it suggested that protein requirements decline with aging?
Tie this to activity level and also if they lose muscle mass they have less protein turnover
What is Cushing’s Disease? What are 3 clinical signs? What are the symptoms?
Pituitary pars intermedia dysfunction
Clinical signs
- increase ACTH
- increase POMC
- increase CORTISOL!!!
Symptoms
- hypertrichosis (excess hair growth)
- sweating
- muscle wasting
- risk of laminitis
- insulin resistance
Treatment for Cushing’s Disease
Dopaminergic control
*with nutrition (less starch and sugar) we can help control the symptoms
Equine Metabolic Disease
- obese
- hyperinsulinemia
- laminitis
- etiology (unknown, genetic)
What would a possible treatment be for equine metabolic disease?
too much insulin = reduce amount of insulin by feeding less starch and sugar (cereal grains) and more forage
What is Laminitis? What are the causes?
Inflammation of laminae causing distal phalanx to detach from inner hoof
Causes
- sepsis/endotoxemia
- toxins
- obesity
- trauma
- fructans
Nutritional management of laminitis
*laminitis in most cases is preventable!!!
- >50% diet related
- too much pasture or grain (rapidly digestible CHO contributing to onset)
When do mares have increased nutrient needs?
During last 6 months of gestation
- increased requirements continue into lactation
