Dairy Cattle Flashcards
In dairy cattle, when does milking begin?
At calving
How long is the lactation period of a dairy cow (per year)?
305 days
followed by a dry period (60 days)
How soon after calving is a dairy cow inseminated?
85 days post parturition
When does peak milk production occur in dairy cattle?
5 weeks after calving
Female calves are kept on artificial milk, weaned at ____ days and reared for another ___ days
Weaned: 35–45 days
Reared: additional 420 days
T/F: Dairy farms have births year round
True
This is different than beef cattle cow-calf operations
For how many lactations are dairy cattle typically profitable for?
3-5 lactations
Then usually culled
Issues include: lameness, mastitis, infertility
*lifespan is 20 years
Fat and protein content in milk will ____ until week 10, then stabilizes
Decrease
What must increase in dairy cattle as lactation increases?
DMI - dry matter intake
When is peak lactation in dairy cattle?
weeks 4-10 (5 is a good reference)
this is followed by a continually decrease until drying off
What percentage of dairy operation costs are feed costs?
40-50%
Milk production is always limited by ______ (25%) and __________ (75%) components
Genetic/heredity - 25%
Environmental - 75%
happy cows produce more milk
A cow in lactation that is feed correctly, will use what portion of feed for maintenance and what portion of feed for milk production?
Half for each
*Said this would be on the exam
What occurs when a cow in lactation is inadequately fed?
It will draw body reserves for maintenance needs and milk production will drop
**said this will be on the exam
In a dairy cow on the first 5 weeks of lactation, the fat content of milk ______, unlike milk _______
Fat content will decrease
unlike milk volume - which will increase (this is peak lactation)
What is the basis of most feed rations on dairy farms?
Roughages (pasture, hay, silage)
They are the cheapest source of nutrients
T/F: Dairy cattle can do well on high quality roughages alone
FALSE
Because milk production is very demanding, dairy cattle have to be supplemented (concentrate feeding/grains)
In cattle, what percentage of the dry matter intake should come from roughages?
60-80%
The rest will come from concentrates and or grain
What is the ideal time to produce good quality hay?
Spring
*20% or less moisture content when baled
T/F: As a crop matures, cows will eat more of the green chop = more energy intake
FALSE
They will eat LESS of the green chop which results in LESS energy intake
**said this would be on the exam
How are silages preserved? What is their moisture content like?
Anaerobic preservation (low O2) - stored in towers, bunkers, bags
Silages have a higher moisture content than dry roughages
What is one of the most popular roughages for dairy cattle?
Corn silage
- highly palatable
- made when kernels reach the “dent” stage
- easily stored and handled
- less labor to harvest and feed
- 8% DM is protein - low on minerals so supplementation is required
- 50% grain on a DM basis
Who is straw fed to on dairy farms?
Cheap alternative for feeding dry cows and older heifers
Who is pasture ideal for on dairy farms?
Dry cows and old heifers
When lactating cows are fed on pasture, what negative side effects may be seen?
Drop in milk production Drop in milk fat Bloating Reduced grain intake Watery feces Difficulty getting cows into milk parlor
What can be done to limit problems with lactating cows that have pasture as a source of nutrition?
Limit grazing to 1-2 hours a day
Feed dry forage before allowing cows on pastures
Bring cows to barn several hours before feeding (feed silage/hay at that time)
Why are grains included in dairy rations?
For energy content
energy content is a limiting factor in milk production
What issues occur if grain is too finely ground?
lower digestibility and lower % milk fat
Acidosis
What is the most commonly used grain in dairy cattle rations?
Corn
high energy
high palatability
Compared to corn cereal, what is the energy and protein content of oats?
Lower energy content than corn
Higher protein content than corn
(lower digestibility than corn)
Oats should not replace more than ____ of the corn in the ration
should not replace more than half
What cereals should NOT be more than half of the grain ration in dairy cattle?
oats
barley (higher protein than corn)
wheat (not commonly used due to high costs)
(Quality/Quantity)
________ of the protein is more important than the _______ of the protein
Quantity is more important than quality
What are some protein supplements that may be used in dairy cattle?
- Corn gluten meal (low palatability)
- Distillers’ grain
- soybean meal (high palatability)
- Sunflower meal (protein and phosphorus)
- Linseed meal (adds shine to hair coat/palatable but laxative)
- Cottonseed meal (palatable but may cause constipation)
What is a non by product meal used to supplement and boost protein levels in ruminant rations?
Nitrogen supplement: Feed-grade urea
**high protein equivalent
What protein supplements are NOT recommended for dairy cattle?
Fish, meat, blood meal
What other by-products of the food industry can be used to supplement cattle rations?
- alfalfa meal
- beet pulp - energy
- Citrus/tomato pulp - energy
- whole cottonseed - high in fat, fiber, energy
- Molasses - energy/palatability
What are some adequate sources for calcium supplementation in dairy cattle?
Limestone, Dicalcium phosphate
Dairy cows suffer more from lack of ____ than lack of any other nutrient
WATER
What is the purpose of placing a rumen cannula fistula?
These are generally placed in a mellow, easy to handle, non-milking cow
It allows you to removed rumen liquor and supplement/supply cows with poor rumen function
What are the four basic groups of microorganisms within the rumen?
Bacteria
protozoa
Fungi
viruses
What is the normal pH of a healthy rumen?
nearly neutral ~ pH 6.5
What is the major product produced by rumen digestion?
Volatile fatty acids (VFA)
**acetate, proprionate, butyrate
T/F: Ruminants are always lacking B vitamins
TRUE
they have a portion of the rumen that is making B vitamins (use of microorganisms) and a portion that needs the B vitamins
When cattle diets include large quantities of starch, what VFAs will be produced in greater amounts?
Proprionate and lactate
When cattle diets are high in fiber, what VFAs will be produced in greater amounts?
Acetate and butyrate
What can be added to a cows diet to enhance the function of the bacteria within the rumen and increase the production of proprionate?
Yeast culture
In early lactation, dairy cows should be fed no more than _____% crude protein (dry matter basis)
18-19%
gradually reduce to 13% CP in mid-late lactation
How much forage (dry matter) should be fed to dairy cows per 100 pounds body weight?
1.5 - 2.8 pounds of forage per 100 pounds body weight
T/F: Fiber in the ration of a dairy cow is required to maintain milkfat
TRUE
Minimum of 15% crude fiber in the diet
Early lactation: increase to 18%
Late lactation: increase to 21%
What would the most adequate (high quality) forage for high-yield lactation dairy cows be?
- straw
- prairie grass hay
- prairie grass silage
- corn silage
- pasture
corn silage
What would be the consequence of feeding a dairy cow a diet with a high level of soluble carbohydrates?
Acidosis and low milk fat
soluble carbs are recommended at a level of 30-35%
What are the most expensive parts of feed rations in dairy cows?
Grains and protein supplements
*home grown grains will lower costs
Describe the four feeding phases of dairy cows
Phase 1. critical occurs during the first 70 days of lactation – highest milk production. Increased grain, protein, fiber above 15%
Phase 2: 70-140 days after calving. Decreasing milk production. Highest dry matter intake
Phase 3: 140-305 days post calving. Continual decreased milk production
Phase 4: 60 day dry period
By how much should grains be increased in dairy cows during Phase 1?
increased by 1 - 1.5 pounds per day
Also increase CP supplementation
How much fat needs to be added to the diet of a dairy cow in phase 1 to avoid weight loss?
1 - 1.5 pounds of fat daily
During what phases does peak production occur in dairy cows?
Phase 1
During what phase does a dairy cow require the highest amount of dry matter intake?
Phase 2
During which phase does a dairy cow have the highest nutrient requirements?
Phase 1
Younger cows need extra amounts of nutrients for growth to reach their full potential.
A two year old requires ___% more nutrients
A three year old requires ____% more nutrients
Two = 20%
three = 10%
What should be done at the end of the dry period to prepare the animal for calving and lactation?
Gradual increase in grain
What are four methods of feeding dairy cows?
Traditional
Challenge or Lead feeding
Total Mixed Rations (TMR)
Automatic concentrate feeders
Is traditional feeding efficient for a large dairy farm?
No
*you need the same person to be feeding every meal to have consistency
This is most commonly done on older, smaller farms
What kind of feeding is described?
Roughages and concentrates are fed ad lib, but separately.
Concentrates may be fed to cows individually according to milk production
Traditional
What are some PROs and CONs to traditional feeding?
PROS: less specialized equipment, in theory - each cow is fed upon her individual needs, allows individual feeding to each cow
CONS: low producing cows are overfed, high producing cows are underfed, hygiene issues when feeding in the milking parlor and extra time cleaning, delayed milking due to slow eaters, less control over total feeding
**more cons to this method
What is challenge or lead feeding?
Variation of traditional: practice of feeding higher levels of concentrate to challenge the cow to reach max milk potential
Provides more concentrates to cows early in the lactation period - less later
What are some factors that go into challenge feeding? What farms use this method?
Used in very small operations and high producing dairy farms
Labor intensive, time intensive, requires good record keeping, requires daily milk weighing, *cows that do not respond to challenge should be culled :(
What is the most common feeding method used on dairy farms?
Total mixed rations
How does TMR work?
All or almost all of the ingredients are blended together. The ration is then fed free choice to all the cows in a large group.
Large herds may be split into multiple feeding groups
When using TMR - does any feeding occur in the milk parlor?
NO
This is a major benefit compared to other methods that may feed concentrates in the feeding parlor
What does TMR contain?
Roughages and concentrates combined to meet the energy, protein, mineral, vitamin, and crude fiber needs of all the animals
What are some benefits to feeding TMR?
each cow will receive a balanced diet that will challenge them to produce to their maximum genetic potential
Feeds more efficiently, fewer cows have GI issues or go off feed, less labor during feeding, not necessary for separate feedings of minerals etc etc etc
What feeding method is best for the hygiene and maintenance of the milking parlor?
TMR
This method eliminates any feeding in the milk parlor - less dust, less manure, less time in the parlor
What are some disadvantages to TMR method of feeding on a dairy farm?
Special equipment for weighing and mixing
Cows may not want to enter milk parlor if there is no food
Hay is hard to include in TMR (so if fed separate, it may be unbalanced for some cows)
Works best with silage
Low producing cows may get too fat
More complex management
What equipment is necessary for TMR feeding?
Mixer blender unit
(many variations)
Weighing device
How should feeding groups be established within large herds for TMR feeding?
It is important to divide the herd into homogenous groups with similar production and nutrition needs
Ex: if a low producing cow is fed with high producing cows - she will get fat. This should be avoided
What are the three types of automatic concentrate feeders and what is their purpose?
Magnetic, electronic, transponder
They are systems that control access to concentrate feeding by individual dairy cows
*a device is attached to each individual allowing them access = $$$$
What does TMR stand for?
Total mixed ration
T/F: When using TMR it is not important to weigh the amount of hay
FALSE
When using TMR, it is important to know the protein and moisture content of roughage such as corn.
- Yes, but only for moisture
- Yes, but only for protein
- Yes for both
- No, not necessary when using TMR
Yes for both
What is the feeding schedule of a calf from birth to rearing?
Colostrum first
Then replacement milk
Weaning diet
(weaned at 35-45 days)
Then reared for ~420 days —> roughage
What are some benefits of calf hutches?
Keeps the calves separate to prevent injury to one another (suckling), less feces exposure, practical and cost effective
Colostrum is the first course of nutrition in neonate ruminants. It promotes ______ transfer from the dam to newborn
Immunoglobulin (IgA, IgM, IgG)
protection against infections in the newborn Essential for survival
Colostrum is a mixture of what nutritional components?
Fat, lactose, vitamins, minerals, complex mixture of proteins
**colostrum proteins actively participate in the protection of the neonate against pathogens and environment
What kind of placenta do cows have? Why is this important for the neonate ruminant?
Epitheliochorial
There is not an adequate transfer of immunoglobulins during gestation –> making colostrum extremely important for survival
Besides immunoglobulins, what other important agents does colostrum contain to support the health of the neonate?
Antimicrobial and anti-inflammatory agents
Growth factors
Cytokines, enzymes, peptides
What form of immune transfer is colostrum to the neonate?
Passive immune transfer
Which animal would have the colostrum with a higher variety of immunoglobulins?
- Cow at first lactation
- Cow at second lactation
- Cow at third lactation
Cow at third lactation
Why is it so important that neonates get colostrum within the first 24 hours post parturition?
Their GI tract is permeable to antibodies at birth - but that closes down by 24 hours
The less than 48 hr old GI tract of neonates is also low in proteolytic activity - which favors uptake of antibodies
Colostrum composition is regulated by _______ during colostrogenesis
hormones
estrodiol and progesterone
What factors affect colostrogenesis?
Species, breed, age, nutrition status, litter size, length of dry period, health status
How much colostrum does a dairy calf need?
*** 1 gallon within 12 hours of birth
(2 quarts within the first hour of birth – then 2 more by 12 hours later)
**absolutely essential to avoid failure of passive transfer
(said this would be on the exam)
How do you feed an orphan calf?
use colostrum from other dairy cows (directly from mother or milked from mother and fed to calf)
*colostrum can be frozen and saved
T/F: Artificial colostrum is equivalent to natural colostrum and can be used for orphan calves?
FALSE
This is nutritionally equivalent but does not have the immunoglobulins the calf would get from it’s mother
Only used as a last resort, emergency situation
If a calf is not suckling after birth, how do you get the colostrum in them?
Colostrum tube feeding
Tube placement is crucial! Don’t want the tube to enter the rumen, need to place the tube in the distal esophagus before the forestomach so it can go down the esophageal groove and straight into the abomasum
***this process needs to be done as gently and cleanly as possible
What clinical signs might you see in a calf that has had failure of passive transfer?
Discharge from the eyes and nose
Polyarthritis - stiff or swollen joints, stiff stance
Depressed attitude
Scours - dhr on rear and back of the legs
What is fed to calves after colostrum?
Replacement/artificial milk
purchased in powder form - mixed with water in the farm and fed to calves collectively or individually
What nutritional qualities are essential for good milk replacer?
Fat: 10-20% (higher during cold weather)
Protein: greater thans 20% (must have milk origin- usually whey)
Fiber: less than .15%
What else can calves be fed (besides replacement milk)?
WASTE MILK
needs to be pasteurized to avoid toxins/illness
- 2nd and 3rd day postpartum milk
- Residue milk (antibiotics)
- mastitic milk
When does weaning from artificial milk begin for dairy calves?
at 6-8 weeks of age
Palatable pellets should be gradually introduced from week one (roughages are not digestible at this age, but it helps develop the rumen)
Second week of age –> clean, palatable, dry straw or hay should be offered
Weaning should take place abruptly when calves are eating ____ - ____ kg/head/day of an early weaning compound for three consecutive days
- 75 - 1 kg/head/day
* this is easier to keep track of, if using calf hutches
* this is commonly around 5-6 weeks of age
What should the diet of a growing heifer consist of?
Good quality forage, some grain/concentrate is needed for growth and development (should be increased in late gestation)
*want to feed them enough to grow, but cheaply since they are not yet producing
T/F: Corn silage is a good choice for breeding age heifers
FALSE
Results in poor growth and fat, short, dumpy heifers –> dystocia
Too much energy and too little protein
*if corn silage is used - must supplement protein to meet the needs
If milk fat is consistently below the average for the breed of dairy cow, you likely have a _____ problem
Nutritional
What is one of the most important characteristics of milk?
Milk fat
What non-nutritional factors affect milk fat?
Season of the year (highest in spring/summer)
Stage of lactation (lowest at peak lactation)
Genetics and breed selection
High somatic cells counts (Mastitis)
Milking equipment problems
Improper handling of samples (over 40F)
How do you evaluate the particle size distribution if feeding TMR?
Penn State Shaker Box
8 strong shakes in each box, then weigh the material in each, add the quantities of each box up to figure out the % of material in each
What is the % of total weight that should be found in each sieve of the Penn State Shaker Box? (upper, middle, lower, bottom pan)
upper sieve: 2-8%
Middle: 30-50%
Lower: 10-20%
Bottom pan: 30-40%
said this would be on the exam
How is body condition score evaluated on dairy cows?
Done by observing the amount of depression around the tail head, amount of fat covering the pin and pelvic bones, and fat around the loin area
T/F: You can make a fair BCS assessment by comparing a dairy cow to beef cow if needed for quick reference
FALSE
beef and dairy cows are scored differently and using different scales - they can not be compared (dairy cows are generally much thinner than beef cows)
What should a dairy cow with a BCS of three look like?
No cavity around the tail head
Fatty tissue over the whole rump and loin area
At what times in life should BCS be checked in dairy cows?
After calving
Early in lactation
Middle of lactation (4months)
End of lactation
What should a dairy cow’s BCS be shortly after calving?
3 - 3.5
then cows will drop weight
What should a dairy cow’s BCS be during her early lactation period between calving and before breeding?
2 - 2.5
cows reach peak (Phase 1 lactation) lactation at this stage
What should a dairy cow’s BCS be mid lactation?
3
At the end of lactation, what body condition score should a dairy cow have?
3.5
How often do adult cows pass feces? How much is produced daily?
Every 2 hours
100 pounds of manure daily
*amount and consistency will depend on the amount of water and the feed in their diet
What should cow manure be evaluated?
It can provide hints about what might be happening with the digestive process
What are the three C’s in manure observation?
Color
consistency
content
What influences the color of manure?
Feed type, bile concentration and passage of feedstuffs and digesta
dark green = fresh forage or pasture
dark brown = hay ration
yellow olive= TMR ration (combination of grain/forage)
Light green-yellow = bacterial infections
T/F: Normal cow feces should have consistency similar to porridge
True
forms a dome-shaped pile 1-2 inches high
If a cow has diarrhea, what concerns will come to mind?
Poisoning, infection, parasites
Extensive hindgut fermentation of carbs
What kind of feces results from heat stress?
Loose
Ideally, fecal samples should indicate _____ digestion
Uniform
What does large proportions of undigested grain or forage in the feces suggest?
poor rumen fermentation
hindgut or large intestine fermentation
What manure scoring should be expected with: Fresh cows Early lactation cows Late lactation cows Far off dry cows Close up dry cows ?
Fresh = 2 - 2.5 Early lactation = 2.5 - 3 Late lactation = 3 - 3.5 Far off dry cows = 3-4 Close up dry cows = 2.5 - 3.5
What color do you expect the feces of a cow on a TMR diet to be?
Yellow-olive
When are metabolic/nutritional disorders most commonly noted in dairy cattle?
around parturition or peak lactation
What causes a displaced abomasum? To which side does it usually migrate and how does that affect the prognosis?
Normally occurs in the first months of lactation due to a change in feed - may be related to the amount of fiber in the diet (causes are not super clear)
Usually will be displaced to the L of the rumen - good prognosis
When displaced to the right of the rumen - prognosis is worse
When does ketosis often occur in dairy cattle?
Common in high producing cows as a result of a negative energy balance –> mobilization of body fat
Can also occur as a complication of placenta retention or metritis
How do you prevent ketosis in dairy cattle?
Avoid overfeeding and over conditioning cows, increase grain after calving, avoid abrupt ration changes, feed good quality forages, do drenching as a routine
What nutritional disorder is most common in animals grazing on rapidly growing lush pastures during the beginning of pasture season?
Grass tetany - LOW magnesium
grass will have low Mg and high K
How do you prevent hardware dz in cattle?
Good feed bunk management
Magnets in the reticulum and feed processing equipment
What is lactic acidosis the result of?
Abnormal fermentation in the rumen
may be clinical or subclinical (pH 5 - 5.5)
Clinical = more severe (pH below 5)
How can lactic acidosis be prevented in cows?
Appropriate levels of fiber Adequate particle size for TMR Adjust cows to high-grain diet gradually Add grain to the dry cows rations before calving Feeding buffers to help maintain rumen
When do you see milk fever in cows?
aka parturient paresis
occurs in mature cows within 48hrs after calving
Low blood Ca = lack of muscle strength and contractility
Who is most susceptible to milk fever?
Older cows and Jersey cows
How can milk fever be prevented in cows?
Low dietary Ca in dry period will condition the cow to draw Ca from bone
Avoid excessive Ca intake during dry period
Supplement lg quantities of vitamin D 2-3 days prior to calving
T/F: Silages typically do not cause nitrate poisoning due to their fermentation process
TRUE
Nitrate poisoning will most often be noted in drought conditions and in green cut forages
Which metabolic disorder is related to low fiber and high grain intake?
Acidosis
Which metabolic disorder is caused by calcium deficiency?
Milk fever
Laminitis is associated with what metabolic disorder?
Acidosis
