lecture 3 Flashcards
what is the water requirement
25-70 ml/kg/day
average horse 500kg
500kg x 50 ml/kg = 25, 000 ml/day
average horse requires : 6 gallon
most of the horses (>90%)get their water requirement by
periprandial drinking = eating and drinking at same time
what is a calorie (cal)
amount of heat (produced by oxdation) required to raise the temperature of 1g of water by 1°Celcius
Kcal = ? cal
1000 cal
1 Mcal = ? kcal = ?cal
1000 kcal = 1,000,000 cal
What will usually be use in horse to calculate the energy value of a feed
Digestible energy (DE) Mcal/day = 1.4 + 0.03 x(Kg body weight = 450) = 14.9 Mcal DE/day
what is the required DE for horses: 1. maintenance 2. light work 3. moderate work 4. heavy work
- 15 Mcal/d
- 20 Mcal/d
- 25 Mcal/d
- > 30 Mcal/d
what are the source of energy
- CHO :
- Non-structural (soluble/non-fiber)
- structural (insoluble Fiber) - fat
- protein
Structural CHO have what type of bones
B-1,4 linkage which are NOT digestible but are fermentable
- Requires cellulase to hydrolyze the linkage
what are the commonest forages
- pasture
- hay
- legumes (alfalfa)
- grasses
> 50% of equine diet should come from what ?
forage feeds
best fermentation occurs at what pH
6.5
fiber will give energy by
the production of VFA during fermentation
what is the 1° energy source
VFA - 30-70% of total DE in horses
why is acetate a better VFA than propionate and butyrate
acetate is better because it provides immediate energy to the muscle cells.
Propionate and acetate have to be converted to glucose before (GNG in liver)
does grain increase the production of acetate
no you decrease acetate with increase grain fed
what are the main VFA in horse
- Acetate : energy for muscle
- propionate: contribute greatly to liver and muscle glycogen storage
- butyrate: least utilized VFA
where are VFA absorbed
in the L.I by passive diffusion and goes directly into the portal blood to travel to the liver and the muscle tissues
T or F: FFA absorption maintains the intestinal pH at an optimal level of 6.5
False it is the VFA
what are more energy-dense feed
- non-structural CHO
- Fat
what are non-structural CHO
- simple sugar (alpha-1,4 linkage)
- digestion begins in the S.I.
what enzyme are required to digest NSC
- amylase
- sucrase
- lactase
are released from pancreas via common bile duct
T or F: horses have limited production of amylase
True: the production is variable from horse to horse. You have to test it
50-70% of NSC will be digested where ?
S.I
the cecum has specialized microbes to digest NSC
- bacillus, lactobacillus, streptococcus
- This is why it is important to know how much amylase the horse produce otherwise a too bid amount will be fermented to lactic acid and cause health problems like acidosis by injuring the mucosa
what are some examples of NSC
- Oats, corn, molasses
- Sweet feed = 50%
NSC is a well-know cause of what kind of disease
colics
how can you improve pre-cecal digestion of NSC
by feeding NSC separately from forage
- processing of starch : corn requires processing to increase digestability
T or F: NSC provide rapidly available energy for horses with a high energy requirement
True
in what kind of disease should NSC be avoided
- cushing’s syndrome
- equine metabolic syndrom
- laminitis
- obesity
excess energy = excess NSC may create what ?
- “hot” horse = hard to handle
- weight gain; excess fat stored
- developmental orthopedic Diseases (young horses)
what are the structural CHO
- -> rouphage:
- low starch
- high fiber
- low DE
what are the non-structural CHO
- -> grains:
- high startch
- low fiber
- high DE
what is the glycemic index
it measures the effects of CHO on blood glucose
what are high and low glycemic feed
- Non-structural CHO breaks down quickly during digestion, releasing glucose rapidly into circulation
- Structural CHO break down more slowly, releasing glucose more gradually into the bloodstream
Corn releases more glucose
what is the difference between Non-structural and structural CHO
Non-structural: they occur either as simple sugars of CHO that can be broken down by the horses enzyme
e.g. glucose, fructose, sucrose, starch
- range from being almost non-existent in grass hay to being a major component in grain diets
Structural: CHO that cannot be digestive by the horse’s digestive enzyme
