Animal Nutrition Test 2 Flashcards
A chicken is a…
Omnivore
How many times does a typical dairy cow chew a day?
42,000
4,700 to eat grain, 10,500 to eat forage, 26,400 for rumination
How much saliva does a dog (carnivore) produce per day?
200 mL
How much saliva does an omnivore (man) produce per day?
1500 mL
How much saliva does a sheep (herbivore) produce per day?
10 L
How much saliva does a horse (herbivore) produce per day?
40 L
How much saliva does a cow (herbivore) produce per day?
60 L
How much saliva does a high producing dairy cow (herbivore) produce per day?
120-200 L
What percentage water is saliva?
99% water
What electrolytes are present in saliva?
Salts of Na, K, and some Cl and Mg
Nah Kendra, Meg and Clara aren’t coming
4 major proteins found in saliva?
Mucin (lubricant)
Lysozyme (disinfectant)
Amylase (starch–> maltose, only farm animal that has it is pigs)
Lipase
8 functions of saliva?
- Moisten
- Solvent (taste)
- Washing
- Disinfectant
- Buffer (bicarbonates buffer VFAs so they don’t damage the rumen wall)
- Nutrients (N from mucin and urea, P, and Na)
- Antifrothing (no foam=no bloat because the cow can burp/eruct)
- Excretion (toxic metals like Hg and Pb are secreted by salivary glands, also fermentation makes blue sulfide line on gums)
What is deglutition?
Swallowing
Chemicals and enzymes in the stomach?
Chemicals: HCl (breaks down proteins, activates pepsin from pepsinogen, optimal pH for enzymes, kills all bacteria so stomach is sterile)
Enzymes: pepsin and rennin (proteins) and lipase. Rennin hydrolyzes casein in milk.
How long is the duodenum or “duodenal loop”?
1 ft
Longest part of the small intestine?
Jejunum
What are the folds in the mucosa layer of the small intestine (primarily the jejunum) called?
Valvulae conniventes
Chief site of food digestion in monogastric?
Small intestine (not stomach!)
3 ALKALINE secretions into small intestine to mix with chyme?
Bile, pancreatic juice, and succus entericus (lubricate, dilute, make more basic)
These are all basic secretions so the can neutralize acidic chyme
What does duodenal juice do?
Secretes enterokinase to activate trypsin, which then activates chympotrypsin
Secreted by the Brunners glands
2 ways that bile salts help with fat digestion?
Solublize and emulsify fats so lipase can digest it, and form an absorbable complex with fatty acids
Digestive enzymes of the pancreas:
For protein digestion: trypsin, chymotrypsin, carboxypeptidase, aminopeptidase
For fat digestion: intestinal lipase (steapsin)
For starch digestion: amylase (amylopsin or pancreatic diastase)
For maltose digestion: maltase (into glucose)
For sucrose digestion sucrose (into glucose and fructose)
For the phospholipid lecithin: lecithinase
How much bacteria do the feces contain by weight?
50 %
This is mostly coliform bacteria, which produces some vitamins (like vitamin K in chickens)
Who has the most extensive and greatest volume in their large intestine?
Monogastric herbivores
Their large intestine (cecum and colon) is about the size of the rumen so it has a large fermentation capacity
It can digest cellulose, make B vitamins, and make bacterial protein (which can’t be digested)
The VFAs produced here are absorbed just like in the ruminant!
What is the valsalva maneuver?
Breathe deep, close glottis, flex ab muscles
What are the components of urine?
Nitrogen compounds, sulfurous metabolites, minerals (Na, P, K, Cl), and water
Minerals found in urine are the same as the electrolytes found in saliva except Mg is replaced with P
Common name for rumen?
Paunch
Common names for reticulum?
Honeycomb and hardware stomach
Common names for omasum?
Many plies and stockmans bible
Common name for abomasum?
True stomach
Relative volume of rumen?
80%
Relative volume of reticulum?
5%
Relative volume of omasum?
7-8%
Relative volume of abomasum?
8-9%
Contents of the rumen generally equal what percentage of body weight?
20%
Amount of liquid in the rumen?
5-60 gallons
Amount of solid material in the rumen?
5-50 lbs
What is the lining of the forestomachs made of?
Stratified squamous (nonglandular so doesn’t make mucus)
When is the rumen partially functional by?
6-8 weeks
What percentage of food is fermented to some degree?
85-95%
What covers the rumen wall?
Papillae. These increase absorption, so the rumen is both secretory and absorptive just like the small intestine
Microorganisms are made of:
50% crude protein with 3% lysine content, and this microbial protein often meets the protein requirements of the animal
They also contain energy, vitamin K, and B vitamins
The B vitamins satisfy the animals B requirements except for niacin in dairy cows and thiamin in feeder cows and animals under stress
They also make enough essential fatty acids for the animal
What percentage of energy do VFAs supply for the ruminant?
50%-70%
Function of the omasum?
Unclear, but probably involved in water and VFA absorption
How much gas do rumen microorganisms make a day?
600 L
Poloxalene
Bloatguard, anifoaming agent that has to be ingested in 12 hour intervals
Other solutions for bloat
2-3 oz of laundry detergent (breaks down the foam by changing the surface tension)
Trocar and cannula in emergency situations
In feedlot cattle, ionophores and increasing the forage portion of the diet
What percent of total digestion occurs postgastrically in the ruminant?
5-15%
Mean time spent in rumen digestive tract
3-4 days, first through after 12 hrs and last through after 10 days
How long do ruminants ruminate?
8 hours a day
What percentage of water and dry matter make up the rumen?
75% water and 25% dry matter
Concentration of bacteria in the rumen
15-50 billion/mL
Number of species of Protozoa found and in each animal
35 species found, 12 in each individual animal
Concentration of Protozoa in ruminant
20,000-500,000/mL
Total number of microorganisms in the rumen
2.5*10^15
Are more VFAs produced from grain or forage diets?
Grain
Gas composition:
65% CO2
25% CH4
7% N2
Some O2, H2, and H2S
What is produced as a fermentation product from deamination of dietary amino acids or NPN sources? What happens to it?
Ammonia (NH3), either absorbed into bloodstream or incorporated into microbial protein or lost as urea
Starch is found in:
Grain
Cellulose is found in:
Forage
What percent forage are dairy rations kept at to avoid Low Milkfat Syndrome?
40% or higher
Rumensin and Bovatec
Ionophores to favor propionate
Not useful for dairy cows bc it would cause poor milkfat and they can make more propionate by adding more grain in the diet
Pasture cattle increase gain by 0.2 lb/day and feed efficiency
Feedlot cows don’t increase gain, increase feed efficiency by 5-8%
Maximum fat to be fed unless its bypass fat
5%, otherwise it’ll hinder fiber fermentation
Megalac and Energy Booster
Protected fats
Can increase fat in a ruminant diet up to 7-8%
Increases milkfat and helps with energy balance
How do bacteria affect protein quality?
Either increase or decrease quality so that it’s the same as theirs (6.8% lysine, similar to soybean meal)
Higher percentage of lysine means higher quality
Bypass proteins
= rumen undegradable proteins like fish, meat, or blood. Benefit: no microbial filter so animal gets it all to itself
Who can better utilize urea: feedlot cattle or range cattle?
Feedlot cattle because they are more energy efficient
Positive associative effect example
N in diet increases utilization of forage
Oklahoma Gold program: feed soybean or cottonseed protein and it’ll help calves better use the energy in grass
Unique mastication qualities of horse
Vertical and lateral jaw movements
Only chew on one side of jaw at a time
Unique saliva qualities of horse
No enzymes in saliva
Liters in a gallon?
4
Unique stomach qualities of horse
Smaller stomach than other specifies (8% capacity. This is a study question!), so feed at least 2 smaller meals a day. Ruptured stomach occurs
Not a lot of muscle activity so food ends up in layers = colic and gastric ulcers
Unique small intestine qualities of horse
No gall bladder, so secrete 300 mL of bile an hour.
Unique large intestine qualities of horse
Big, accounts for over 60% of total gut capacity, 25 feet long
Divided into large and small colon
Horse on a forage diet will get most of its energy from the large intestine bc of VFA absorption
Cecum is the primary area of water absorption
Problem: impaction of large intestine may easily occur and be fatal
What can be made from propionate?
Glucose, probably why it’s so energy efficient
Compare fiber digestion in the horse and ruminant
Horse is only 2/3 as good at fiber digestion because food goes through their digestive tract much faster
Horse fat digestion success rate
90% or better in rations up to 20% fat
Do horses and cows need to be fed essential amino acids?
Just horses bc they can’t digest the microbial protein made in their large intestines, but cows can digest the microbial protein made in the rumen when it gets to the abomasum
How long after birth can a baby horse absorb immune antibodies in colostrum?
36 hours
Another name for amylase
Ptyalin
Human amylase is 100 times more powerful than pig amylase
Capacity of a pig stomach
2 gallons
Unique stomach qualities of pig
No rennin in gastric juice
24 hours to empty full stomach
Unique small intestine qualities of pig
60 ft long
2.5 gallon capacity
Pancreas makes insulin for carb metabolism
Trypsin
Activated by calcium and enterokinase
Chymotrypsin
Has coagulating action on milk (makes sense because pigs don’t have rennin in gastric juice)
Functions of bile other than in fat digestion and absorption:
Aids in absorption of soluble vitamins
May activate pancreatic lipase
May accelerate the action of pancreatic amylase
Unique large intestine qualities of pig
16 feet long
2.5 gallon capacity (cecum holds .5 and colon holds 2). This is the same capacity as the small intestine
Unique mouth qualities of bird
No teeth
No soft palate
No separation from pharynx
Few, poorly functioning salivary glands that produce amylase
Order of bird digestive organs starting with esophagus:
Esophagus, crop, proventriculus, gizzard (ventriculus)
Crop
Food storage, moistening
Produces milk in doves and pigeons
Some species undergo fermentation here
Doesn’t affect bird if removed
Proventriculus
Stomach, no digestion occurs here bc food passes through in 14 seconds, except for in carnivorous birds
Gizzard
Muscular grinding organ, contains grit for grinding
No enzymes secreted here but enzymes from proventriculus work here
Unique small intestine qualities of bird
Jejunum and ileum aren’t separated
No lactase found here
Villi don’t have lacteals (lymph capillaries)
Unique ceca qualities of bird
2 of them
Water reabsorption, fiber digestion, and water-soluble vitamin synthesis happens here
Chicken doesn’t need its ceca
Unique large intestine qualities of bird
No colon or rectum, only 2-4 inches long
Water absorption
Vitamin K synthesis occurs here in chicken
Rate of passage in birds
24 hours, half is passed within 4-6 hours so this is fast
What measurements do growth experiments usually include?
Absolute gain and then rate of gain (average daily/weekly absolute gain or relative gain)
What diet do animals get in growth trials?
Some get test feed and others get known basal diet
Feed efficiency
Weight gain per unit of feed
Paired feeding experiment
2 animals eat same amount so we know feed intake isn’t affecting performance
Advantages of growth trials
Lots of data for cheap
Conditions are similar to normal environmental conditions
Easy to get measurements
Can be applied to commercial production
How to determine body composition changes without grinding a whole carcass?
9-10-11 rib cut
Digestion trial preliminary period
3-10 days
Digestion trial collection period
4-10 days
Number of animals needed for a digestion trial
4-6 animals
Why use indicator method?
When it’s difficult to measure total feed intake or collect total feces. Remember, apparent digestibility is (I-F)/I times 100
Internal indicator
Indigestible thing usually found in feed, such as lignin or silica
Problem: difficulty in analysis and incomplete recovery
External indicator
Not usually found in feed, chemicals
Chronic oxide has to be given in a pill or mixed in a feed
Irregular excretion
Incomplete recovery
Have to recover stained particles by washing and sieving
Digestibility by Difference
One feed might affect digestibility of another (associative effect) so you use this method to test a feed that’s mixed with other feeds
Some animals get basal diet, others get basal diet AND test feed (not either or!)
How do you determine true digestibility of N in ruminants?
Regression line to find amount of N in feces when fed no protein (this is the endogenous nitrogen) then subtract this from the nitrogen found in the feces
Balance trial
What happens AFTER absorption. Is it used or expelled?
Find total intake and total excretion (urine, feces, expelled air, everything!) to see if there’s a net retention or loss of the nutrient
Why use purified diets?
To determine quantitative nutrient requirements!!
You can change the concentration of one nutrient and not change the others, and there’s no unwanted stuff that could change the utilization and requirements for the nutrient in question
Advantage of simulation techniques (like cannula) for rumen digestibility?
Cheaper; digestibility trials cost a lot for cows
Why do similar animals digest diets to different extents?
Differences in mastication and stomach capacity
How do you get an accurate weight in growth trials?
Get 2-3 consecutive daily weights
Gut fill hindering true weight measurement is a problem, especially in ruminants
Why use the nylon bag technique?
Comparing feedstuffs (actual values aren’t the same as digestion trials but you can still compare) and study rumen digestion of GRAIN
What can the body lose and still survive (fat, protein, water?)
Almost all of its fat, half of its protein, but 10% water loss causes death for most (20% loss is possible for some)
What chemical component yields the most metabolic water upon hydrolysis?
Fat
What chemical component supplies the most net metabolic water?
Carbs
What percentage of their total water do cows and horses derive from metabolic water?
5-10%
In some species it can contribute up to 50% of it
Water content of most species:
70-75%
Water content in individual tissues:
90%
How much water (percent) does a normal adult human have?
60-65%
Intracellular fluid compartment water accounts for how much of total body weight?
40-45% of body weight
Extracellular fluid compartment water accounts for how much of total body weight?
20% of body weight
1/3 of all body water.
Water in the gut and urinary tract accounts for how much of total body weight?
25-30%
How saturated is air when it’s expelled?
90% saturated
What percent of water is eliminated by the kidneys, lungs, feces, and skin?
Kidneys: 60%
Skin: 18%
Lungs: 15%
Intestines: 7%
Water to dry matter intake ratio?
3-6 water: 1 DM
2-5 kg water: 1 kg dry feed
Water to milk production ratio
1 water: 1 milk
What portion of body mass is water? Molecules?
1/2 - 2/3 of body mass in adults, up to 90% in newborns
99% of molecules in body are water
How many Cal does 1 g of water take up?
580 Cal
Water to DM for cows?
4:1
Water to DM for sheep?
2.5-3 :1
Better at conserving water than cows
