Title: Carbohydrate Nutrition of Canines
1Carbohydrate Nutrition of Canines
2Carbohydrates
- Major energy-containing constituents of plant
material - 60-90 of plant DM
- Cellulose is most abundant CHO in nature
- Animals have no specific reqt. for CHO
- In spite of physiological significance of glucose
- Sufficient precursors (AA, glycerol), dogs can
synthesize glucose - gluconeogensis
3Carbohydrates
- Certain physiological states require more glucose
- Necessary for nerve, blood, and mammary cell
synthesis - While not an essential nutrient, important in
feed formulation - Inexpensive, used in extrusion to maintain shape,
gelling agents in canned dog food
4Classification of CHO
- Monosaccharides simple sugars containing single
unit (glucose, fructose, galactose) - Disaccharides 2 monosaccharides linked together
(sucrose, lactose-only CHO of animal origin)
5Classification of CHO
- Oligosaccharides 3-80 units with /-
nutritional properties - Polysaccharides multiple monosaccharides linked
together in long, complex chains - Starch main CHO in pet food (hydrolytically
digested) - Cellulose, Hemicelluose, Lignin, Pectin, Gums
structural CHO or fiber (fermentatively digested)
6Polysaccharides
- Most common type of CHO in pet foods
- Largest single type of CHO found in pet food is
STARCH - Economical and available
- Supplied by plant feedstuffs (corn, rice, wheat)
7Evaluation of selected high starch flours as
ingredients in canine diets
- Background
- Cereal grain represent 30-60 DM of many pet
diets - Starch component can be an excellent source of
energy - Form of starch is variable and the result is
incomplete digestion - Digestibility ? with cooking/processing
- Effect of extrusion not extensive investigate
prior to this research effort
8Evaluation of selected high starch flours as
ingredients in canine diets
- Objectives
- Quantify amount of different starch fractions in
cereal flours - Alone and part of extruded dog diet
- Determine effects of addition on nutrient
digestion - Prior to terminal ileum (hydrolytic digestion)
- Total tract (hydrolytic and fermentative
digestion)
9Evaluation of selected high starch flours as
ingredients in canine diets
- Results (see tables in text)
10Glycogen
- Primary storage CHO in animal tissues
- Glycogen loading of athletes high CHO intakes
and submaximal training strategies shown to
increase muscle glycogen storage and prolonged
exercise intensities - humans
11Glycogen
- Loading not effective in dogsWHY?
- CHO loading ? fecal bulk
- Increasing CHO ? energy density
- Canine athletes rely more heavily on lipid (fat)
metabolism - Downey et al. found that CHO intake was
negatively correlated with endurance time of
Beagles (fat spared glycogen in muscle) - Reynolds et al. observed that sled dogs fed high
fat diets used less muscle glycogen than those
fed a high CHO diet - Glycogen sparing more effective
- Remember glycogen depletion deterioration in
performance
12Dietary Fiber
- Definition structural CHO resistant to
digestion by mammalian intestinal enzymes - Bond configuration
- Resists enzymatic hydrolysis to monosaccharides
- Components pectin, hemicellulose, cellulose,
gums, and lignin (only non-CHO fiber) - Methodologies crude fiber, detergent fiber,
total dietary fiber (soluble vs. insoluble
distinction)
13Action of fiber in GIT of dogs
- Food intake and nutrient digestion
- Byproducts such as fruit pomaces at 8 of diet
will decrease digestibility - Viscosity of ileal digesta prevents nutrient
digestion/absorption - Beet pulp added at 8 does not alter digestion
- Energy diluent
- Food intake is not altered when fiber added at
these physiological concentrations
14Action of fiber in GIT of dogs
- Intestinal Transit Time
- Viscous, soluble fibers (pectin, gums) slow TT
- Insoluble (bulk) fiber can increase TT by as much
as 50
15Action of fiber in GIT of dogs
- Fermentation
- Fibers vary on rate and extent of fermentation
- Major endproducts of fermentation SCFA
(short-chain fatty acids) - Acetate, propionate, butyrate
- Health benefits (discussed later)
16Action of fiber in GIT of dogs
- SCFA
- Dogs cannot use to extent ruminants canare still
important energy source - Cells of large intestine are very active and have
a high turnover rate - Cells rely on SCFA as energy source to regenerate
new intestinal cells
17Dietary Fiber Fermentation in Dogs
18Action of fiber in GIT of dogs
- Insoluble fiber (lowly fermentable)
- Bulk
- Satiety
- Improve intestinal tract motility to maintain
optimal transit time through the intestinal tract - Soluble fiber (moderately to highly fermentable)
- Delays gastric emptying
- Increases fermentation and SCFA production
19Incorporating fiber into pet food diets
- Generally, most standard diets will contain 4-6
fiber - Premium pet foods intestinal health
- Generic pet foods least cost formulation (so
may exceed 6 fiber) - What type of fiber should be used?
- Single source should provide good stool
characteristics w/o significantly decreasing
nutrient digestibility
20Incorporating fiber into pet food diets
- Fiber blends have been formulated to simulate
ideal fiber - 80 insoluble and 20 soluble
- BUT, some insoluble fibers too unfermentable
(peanut hulls) and some soluble fibers too
fermentable (liquid stools) - This blending alleviates necessity of finding
single fiber source and expands number of
potentially beneficial fiber sources
21Fibers used in pet food industry
- Grain co-products (rice bran, soy hulls, wheat
middlings, corn gluten feed) - Pomaces (apple, grape, tomato)
- Wood cellulose (not fermentable)
- Peanut hulls (not fermentable)
- Beet pulp (standard fiber source)
- Gums
22Oligosaccharides (OS)
- Definition Glycosides (CHO) of 3 to 10
monosaccharide units - Contain unique glycosidic linkages, OS are
INDIGESTIBLE in small intestine - fermentable
23Where do they come from?
- Enzymatic synthesis from simple sugars
- Lactose in high concentrations will form
transgalactooligosaccharide (TOS) - Controlled hydrolysis of polysaccharides
- Inulin ? Fructooligosaccharide (FOS)
- Extraction from plant material
- Soybean OS (raffinose, stachyose, verbascose)
24Properties of OS
- Not pure
- Mixtures of different chain lengths
- Contain mono and disaccharides
- Contain parent compound
- Water soluble
- Mildly sweet (0.5 times that of sucrose)
25Properties of OS
- Energy value of 1.5 to 2.3 kcal/g
- Less efficient source due to fermentation
- Some are PREBIOTICS
- Indigestible food ingredient that positively
effects the host by selectively increasing
beneficial bacteria in the gut
26Significance of OS in companion animal nutrition
- Prebiotic OS are fermented in the colon where
they selectively stimulate health-promoting
bacterial populations - At the expense of deleterious bacteria
- Beneficial bacteria Bifidobacteria,
Lactobacilli, Eubacteria - Deleterious bacteria Staphylococci, Clostridia
- Neutral bacteria Streptococci, Bacteroides, E.
coli (not all are bad)
27Why do beneficial bacteria increase?
- These good bacteria grow best on easily
fermentable substances (OS!) - As they grow, they produce lactate
- Acidic product which decreases intestinal pH
- Bad bacteria decrease
- WHY?
- Can not survive at low pH
- Have no where to bind to on intestinal wall
because good bacteria are occupying binding sites
28Bifidobacteria
- Associated with reduced susceptibility to enteric
pathogens and intestinal disease - Reduces the concentrations of gut ammonia,
amines, and phenols (toxins that are a source of
odor and can be carcinogenic) - Stimulate immune function (antibody levels)
- Enhance mineral absorption by as much as 40
29Adverse effects of OS in pet food diets
- At high supplementation levels
- Loosely formed stools
- Flatulence
- Abdominal pain
30Do natural foodstuffs contain OS?
- Wheat
- Middlings (0.5)
- Bran (0.4)
- Germ (0.5)
- Peanut hulls (0.3)
- Barley (0.2)
- Soybean meal (1.5)
31Considerations in feeding OS to pets
- Consider the type of pet being fed
- Cats less fermentative capacity than dogs
- Consider the age of animal being fed
- Geriatric population tends to have less desirable
intestinal microbial balance (deleteriousgtbenefici
al) - Geriatric population more prone to intestinal
diseases
32Considerations in feeding OS to pets
- Consider the type of diet being fed
- Plant-based diets will contain more OS
- Usefulness of OS may be increased in high
protein, meat based diets - WHY?
- High protein diets result in increased production
of odorous compounds which may increase risk of
cancer - High protein diets are low in fermentable CHO
which results in higher colon pH - Higher pH is associated with increased
concentrations of deleterious bacteria
33Considerations in feeding OS to pets
- Determine the level of OS to supplement
- Minimize potential side effects
- Gradual adaptation to OS is advised
- About a week prevents flatulence, diarrhea, etc.
- OS must be consumed on a regular basis to be
effective - To maintain beneficial bacteria populations
34Recommendations for feeding OS
- Studies have shown levels between 0.1 to 10
- Remember, these products are expensive!
- Generally see 0.1 to 0.5 inclusion rates