Studied by 0 peopleWhat is Fescue Toxicosis (KY 31)?
Endophyte fungus produces ergot alkaloid toxins
What happens when broodmares eat too much Fescue?
Dystocia, prolonged gestation, enlarged foals, thickened placenta, and agalactia
What happens when cattle eat too much Fescue?
“Summer Slump,” Agalactia, thickened placenta, aborted fetuses, poor appetite
Exacerbated by fertilizing with high N; fat necrosis causes problems with digestion and calving
How to prevent Fescue Toxicosis
Pasture Management is the only option
pull mares off 60 days before foaling; hay
Test pasture for fungus; reseed
Dilute by the planting of red/ white clovers, alfalfa
Consider endophyte-free stains
Keep pastures short to prevent seed heads
Fertilization may make the problem worse
Factors that affect reproductive performance
Nutrition, Environment (temp, humidity, seasonality), Anatomical defects in the reproductive tract, Endocrine system imbalance, diseases
Over-condition
rarely observed, increased dystocia, you see them a lot in “hobby farmers” and show animals
“Flushing”
Increasing the level of nutrition (30 days before breeding)
Why is flushing done
Increases the rate of ovulation in the herd
Effective for heifers, ewes, and sometimes guilts
How often do producers want a cow to calve
every 12 months
Most cows probably won’t show estrus until after day 45 postpartum, therefore only ____ estrous cycles to get them bred (21 d)
2
A ___________ program is especially important for heifers calving for the first time
nutrition
Why do they need extra nutrients?
Will be lactating for the first time, still growing, uterine involution (preparation for another pregnancy)
Highest percentage in A.I. and why?
95% is turkey because they need a lot of muscling, 80-90% is dairy cattle because the bulls are mean
Advantages of A.I.?
Maximum use of genetically superior sire
greater number of offspring
facilitates progeny testing of young sire
enhances genetic progress
Greater selection of affordable sires
Use deceased or dangerous sires
Aid in reduction of diseases
Improvement management
improved her record
improve uniformity of calf crop
Disadvantages of A.I.
Increased labor, management, and facilities
Accentuate poor genetics by using inferior sire
Future of A.I.
Brightened by the use of Lutalyse, Estrumate, and Synchromate-B for the synchronization of estrus
Future use would be increased if we could
Successfully sex semen
Breed lactational an-estrous cows
Semen Collection
Artificial vagina
for bulls, stallions, and rams
Not for boar (apply pressure by gloved hand)
Used when mounting female or train to mount dummy
Electro-ejaculator
Probe inserted into the rectum
Electrical stimulation causes ejaculation
If collected too frequently, number of semen per ejaculate decreases
After collection, semen evaluated for:
volume, sperm concentration, motility of sperm, abnormalities of sperm
frozen semen lasts _____________
indefinitely
For maximum conception, the sperm and ova must be at the site of fertilization at the __________
peak of their fertility
Site of semen deposition
In uterus of cows and mares
Deposition in uterine horn and has lower conception due to uterine trauma and possible infection
Superovulation
Hormone treatment of the female to induce multiple ovulations
Uses: multiple births and embryo transfer
Embryo Transfer of Advantages
Increased reproduction of valuable dams
Decreased time of proof of dam through a greater number of progeny
Extended reproductive life of injured or older dams
Transport of exotic breeds or proven stock to restricted or underdeveloped areas
Embryo Transfer Disadvantages
Costly…although it is decreasing
ET offspring are not necessarily genetically superior
Success rate is variable and not guaranteed
_______ hormone is commonly used to induce cattle
FSH
___________ are used to synchronize the estrous cycles of the donor cow and recipient cows
Prostaglandins
What are prostaglandins?
They resemble hormones in their actions, but are quite different chemically (produced by many tissues in the body)
Embryo Transfer Procedures
Selection (transfer donor must be healthy, cyclic animals of superior genetic makeup)
Synchronization (donor and recipient animals must be in the same stage of the estrous cycle)
___________ is the distinguishing feature of animals
Lactation
Mammary glands serve two functions ________ and ____________
Provides nutrition and source of passive immunity to offspring
In the U.S. milk primarily comes from _____ lesser extent _____ and ________
cows
goats and sheep
What makes a mammal?
Most have hair, all have mammary glands (modified sweat gland)
Critical part of repro strategy in mammals
Lactation
Great variation in __________ glands among species
glands
How many glands and teats do cows have?
4 glands, terminate in 4 teats
How many glands and teats in the mare?
4 glands and 2 teats
How many glands in the sheep and goat?
2 glands and 2 teats
How many glands for multiparous animals?
6-20 glands in two rows along abdominal wall
A gland is __________
a secreting organ
A secretion may be _____, _____, or ________
poured out (secreted) onto the surface, poured into cavity, or taken into blood
Milk is synthesized and secreted from epithelial sells in a tissue consisting of ___________
alveoli
What is an exocrine gland?
Gland that secretes fluid into a duct
What is the endocrine gland
Ductless glands that secrete hormones into bloodstream, endocrinology
What are antimicrobial proteins in milk?
Lactoferrin (binds iron (Fe) required for bacterial growth), and Lysozyme (enzyme that hydrolyzes bacterial cell walls), Immunoglobulins (Ig)
What is the composition of milk? What makes up the most of it?
Water makes up the most of milk
Solids: Also contains lactose (1 glucose + 1 galactose), fat, protein, minerals, vitamins, other
How much of cows milk make up water and solids?
88% water and 12% of solids
The more fat in the milk, the more _______ the milk is
yellow
Time of sampling during milking
First-drawn milk (fore-milk) lower in fat and increases as milk is removed
“Fat leaves _________”
last
Fat % varies by __________
season
Higher in ________ and __________
fall and winter
Lower in ___________ and _____________
spring and summer
Temperatures >85
milk accentuated with high humidity
What are factors that affects milk production
Inheritance determines potential
Low producers vs. high producers
Feed and management determine whether potential is reached
Proper feed and care
Production influenced by herd health
Male offspring cause ________ milk production
greater
males are heavier and grow more quickly
Adjust production to the ________ of the calf
consumption
continue milking the cow or put on another calf
Multiple births produce _________ milk than females with single births
more
Age of animal- max production at _____ yrs.
6
Younger and older females produce less milk vs. females that have had _________ lactations
several
__________ needs greater during lactation than gestation
nutritional
Inadequate _______ or _________ forces cow to draw from her own body to sustain milk production
quality or quantity
Mastitis
Inflammation of the udder
Most costly disease of dairy cattle
What is mastitis caused by?
Usually caused by chronic infection of streptococcus and staphylococcus bacteria
What are the three main causes of mastitis?
Dirty or poorly adjusted milking equipment, poor milking practices (dirty animals), and injuries to cows because of their surroundings
Mastitis is recognized by ___________
milker
Detection or a symptom of mastitis is
clots or flakes in milk
What happens to the udder when the cow has mastitis
quarter of udder is sensitive to touch
she kicks a lot when touching there
swollen or hot to touch
How to test for mastitis?
Tested for via California mastitis test
How to treat mastitis?
Treated by intramammary injection of antibiotics
Antibiotics in milk are illegal; not destroyed by heat
Observe withholding periods
Dump it down the drain or use it to feed calves
How to avoid mastitis?
More frequent milking to reduction pathogen load and reduce growth medium (milk)
Prior to birth, fetus is in a ___________________ environment
sterile, protected, moist, and warm
At birth, fetus is exposed to ___________ environment
cold, dry
exposed to harmful organisms and predators
_______ is of paramount importance and why
Milk
survival, development, and growth of young
Why is Colostrum important?
Newborn has little or no immunity
Transfer of immunoglobulins
passive immunity transfer
Protect from harmful microorganisms that cause illness
Intestinal absorption of Ig lasts only 24 hours
Intestinal wall of newborn permits antibody absorption
Newborns must receive colostrum early
The gut wall becomes less porous allowing little absorption
Should have frozen colostrum on hand
Greater variation in milm composition occurs after ________
calving
Colostrum
Greatest variation in milk composition occurs after calving
Transition from producing colostrum to producing normal milk takes _____________
3-5 days
Milk not salable until the __________ milking
11th
Composition of Colustrum
Contains antibodies, Vitamin A and D, fat, protein, most minerals
Mammary gland that lactates ___________ is not genetically favorable
Continually
Glands develop and function in concert with the _______________ cycle
reproductive
Mammals reproduce ___________ times in their lives
multiple
Mammogenesis
structural development or growth of mammary gland
Lactogenesis
associated with the end of pregnancy and parturition; tissues changes from non-lactating to lactating state
Milk secretion
synthesis of milk by epithelial cells
Milk removal
passive removal from cisterns and ejection of milk from alveolar lumen
Lactation
milk secretion + milk removal
Galactopoesis
maintenance of lactation
Suspension
Maintain attachment to the body
Median Suspensory Ligament
Separates left and right halves of udder
Lateral suspensory ligament
outer wall of udder
Four Glands or Quarters
Separate from each other- milk cannot move between quarters
Teats are ____ inches long in cow
2-2.5
hollow tubes of skin, muscle and erectile tissue hanging from udder
Valve close top and bottom; sphincter muscle closes
Bottom opening = “streak canal”
What happens when cows are born with extra teats?
Removed less than 1 year old
Milk collecting system explain
Many collecting ducts (large and small)
Gland cistern and teat cistern
Alveolus
Sac-like structure with hollow center
Basic milk-producing structure in udder
Very small ~1 million/ cu. inch
Alveolus
Lumen lined with single layer of epithelial cells, what does the lumen do?
Remove nutrients from the blood
Transform nutrients into milk
Discharge milk into the center of the alveolus
Epithelial cells are surrounded by contractile _____________ cells involved in milk ejection
myoepithelial
Innervation (neural system) inside udder is _______
sparse
Note
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