equine nutrition Flashcards
what makes up the foregut
- mouth
- esophagus
- stomach
- small intestine
what makes up the hindgut
- cecum
- large colon
- small colon
- rectum
what is the function of the mouth
- selection
- chewing
- saliva
- swallowing
what type of teeth do horses have and what are incisors and molars used for
- hypsodont teeth
- incisors: shear forage
- molars: grind food
what is the capacity of the small stomach
only holds 2-4 gallons in a 1100 lb horse
what does the stomach continually secrete
HCl and Pepsin
how long is the small intestine
50-70ft
what occurs in the SI
- most nutrients digested (proteins, CHO, fat)
- most vitamins and minerals absorbed
- water not absorbed - helps move the food through GI
what does the pancreas do
- islet cells secrete insulin and glucagon
- production/secretion of enzymes
what does the liver do
- emulsification of fat
- bile secreted continuously by liver
- no gall bladder for bile storage
what is the purpose of LI
- forage fermentation
- water absorptoin
where are liquids passed to in the GI tract
cecum
what is the cecum
- 3-4 ft long
- contains bacteria to digest fiber and simple CHO
- blind pouch, digesta moves in and out
what is microbial fermentation in the cecum
- bacteria, protozoa, fungi
- VFA
- B-vitamins, VK
- gas production
absorption in cecum
- fermentation products
- VFA usef for energy
transit time in cecum
- slow - 38 to 48 h
- liquids - 5 h
how long is the LI and how many gallons is it
- 10-12 ft long
- 14-26 gallons
what are the 4 parts of the LI
- right ventral colon
- sternal flexure to left ventral colon
- pelvic flexure to left dorsal colon
- diaphragmatic flexure to right dorsal colon
where are common places for impaction
sternal and diaphragmatic flexures
how long is the small colon and how many gallons does it hold
- 10 ft long
- 5 gallons
what is the function of the small colon
- water absorption
- formation of fecal balls
how long is rectum
1 ft
what is the function of the rectum
storage reservoir
what are the functions of carbs
- glucose - fuel for tissues (muscle and liver glycogen)
- fiber - affects GI motility and alter absorption of other nutrients
what are the types of feeds that contain CHOs
- starch - faster breakdown (cereal grains)
- fiber - slower breakdown (forages)
- high CHO to glucose then fat (obesity and excitability)
lipids
- high energy density
- absorb fat sol vitamins
- natural feedstuffs = 2-4%
- high fat feed 10-12%
- no gallbladder so can’t digest high fat diets
what can fats do
- increase energy density
- improve body condition
what are the most common fats
vegetable oil or rice bran
how much fat can the average horse digest
17-18 oz of fat
what is the most expensive component of the diet
protein
what does protein do to diet
- provides AA
- used to increase muscle mass
- important for lactating mares and growing foals
- provides some energy
what are signs of protein deficiency
- weight loss, muscle
- poor performance
- rough, course hair
what are minerals needed for
- maintenance
- fluid balance
- nerve conduction
- muscle contraction
what does sweating increase the need for
Na, Cl, and K
what is the best source of vitamins and minerals
pasture
calcium
important for foals skeletal growth
phosphorus
ratio of Ca:P = 2:1
magnesium
role in protein synthesis and metabolism
copper
deficiency could lead to cartilage malformation
zinc
interfere with Cu absorption if too high
manganese
needed for cartilage generation and some repair
what are structural CHO
forages or roughages
* pasture, hay, cubes
what are non-structural CHO
concentrates
* cereal grains
* protein supplements
* mineral supplements
* vitamin supplements
how much should horses consume of forage per day
at least 1.5% of their BW
* 1000 lb horse = 15 lb DM as forage minimum
legumes
- higher in protein and energy
- more leaves than the grasses
- require optimal growth conditions (warm weather and good soil)
grasses
- grow in humid and cold weather
- survive in poor soil conditions
what is an example of a cool season grass
timothy
what is an example of a warm season grass
orchardgrass
what is an example of a legume
alfalfa
properties of grains (concentrates)
- fiber - low
- energy - high
- protein - low
- cost - reasonable
oats
- most popular
- lower energy value
- higher fiber
- more palatable
- more digestive
- can be expensive
corn
- very palatable
- 2x energy as oats
- low in fiber
- easy to over feed
- mold can be lethal
wheat
- mostly for humans
- expensive
- small hard kernels
- high energy
- lower palatability
milo
- small hard kernel
- not palatable
- used in grain mixes
- high energy
- low fiber
barley
- hard hulls
- medium fiber and energy
flaxseed
- high in omega 3
- 35% protein
- 85% digestible
rice bran
- high energy
- high in fat
- high in fiber
- very palatable
beet pulp
- highly fermentable fiber
- used in high fiber feeds
- low calorie, sugars
rye
- high energy ingredient
- used in mixtures
how many hrs per day do horses graze
12-16 hrs
how much do horses consume daily
2.5% BW
what are balancer pellets
- pellets with concentrated vitamin and minerals
- fed with a commercial concentrate or oats of a horse requiring higher energy to maintain weight
males
- less susceptible to reproductive problems caused by nutrition
- more nutrient requirements than maintenance
- obestity can make lethargic (lose libido, less fertile)
females with poor nutrition
- prevent cycling
- decrease # of eggs ovulated
- decreased birth weight
obese females
- delay puberty
- decrease fertility
- increase embryonic mortality
physiological events in trimesters 1 &2
early gestation
- embryo development
- fetus has priority
- no extra nutrients required for mares
nutrition in trimesters 1&2
- maintenance
- mostly pasture or grass/legume hay
- 10% CP
events during trimester 3
late gestation
- fetal growth/development
- fetal priority over mare
- decreased GI space
- maintain condition for early lactation
nutrition during trimester 3
- forage: ad libitu, to quality hay or pasture
- energy: increase 12-14% above maintenance
- CP: 12%
- vitamin A and E increase (IgG)
- mineral requirements Ca .5: P .35
tall fescue can be ___
toxic
* contain endophyte that produces ergolavine
symptpms is grazed in last trimester
- prolonged gestation
- abortions
- premature separation of placenta
- retained placenta
- agalactia
fescue
- check for tall fescue in pastures
- unless endophyte-free varieties planted
- remove brood mares 30-90 days before foaling
early lactation
- highest energy requirement
- dietary protein and fat influence milk composition
nutrition in early lactation
- forage: high quality grass/legume mix
- CP: 14-16%
- Ca (.5%): P (.35%)
physiological events in late lactation
- milk yield decreasing
- maintain mare and foal condition
- pasture quality decreasing
- growth rate stable
- foals cartilage and bone maturing
nutrition in late lactation
- forage increasing
- milk decreasing
- creep feeding foals
order of growth
- bone
- muscle
- fat
what is the growth rate
~2.8 lbs/day
what is wrong with rapid growth
- lead to bone growth problems
- DOD = developmental orthopedic disease
what growth stage has the highest growth requirements
weanlings
* rapid growth rate
* protein and energy needs to be higher
when does creep deeding occur
8-12 weeks old
issues with weanlings
- winter and weaning - diet change
- developmental disorders
- attention to growth, condition, and development
- maintain stable growth
- minimize stress
nutrition in weanlings
- quality forage
- multiple feedings
- CP - 14-16%
- Ca - 0.8-1%
- P - 0.5-0.7%
nutrition in yearlings
- quality forage
- CP: 12%
- Ca: 0.8-1%
- P: 0.5-0.7%
- multiple feedings
season in yearlings
- day length
- temo
- pastyre grows rapidly
- increase intake
how much energy is needed for very heavy activity level (race, event, endurance)
- 2x energy needed
- from 16.7 to 34.5 DE
what are readily available CHO
- sugars and starches
- rapidly digested and absorbed in SI
what are slower available CHO
- beet pulp or soy hulls
- fermented in LI
- takes longer to turn to energy
endurance horses
energy utlilization
- long term exercise utlilizes fatty acids as primary energy source
- need muscle glycogen
racehorses
energy utilization
- short term exercise
- perfominantly uses muscle glycogen
pre-exercise feeding
- hyperglycemia occurs after digestion of grain meals
- glucose and insulin peak 60-90 min after meal (insulin promotes fat storage) (exercise wil use the more available CHO)
post-exercise feeding
- specifically for endurance horses (replete the glycogen, 2-4 lb of a cereal grain an hour after exercise)
water
- exercise: increases heat production
- dissipated in sweat and respiration
- increase losses of electrolytes (Na, Cl, K)
- dehydration decreases performance
what are the largest portion of electrolytes
Na, Cl, K and in smaller amounts Ca and Mg
what should the first ingredient be in electrolytes
salt (sodium chloride)
* if it doesn’t taste like salt it will not do anything
