Lab Practical 2 Flashcards
What are the functions of the 4 placental membranes?
-Protection
-Nutrition
-Respiration
-Hormone Production
What does the crown-rump length growth curve suggest about energy requirements during the first stages of gestation?
Low requirement prior to attachment then High energy needed during logarithmic (exponential) growth phase
Cow/Sheep/Goat Pregnancy Signal
Interferon Tau
Pig Pregnancy Recognition signal
Estrogen
Horse Pregnancy Recognition Signal
Not sure, most likely movement of embryo
Mouse Pregnancy Recognition
Prolactin
Human Pregnancy Recognition Signal
Human Chorionic Gonadotropin
What type of placenta is most efficient and why
discoid- fewer layers of blood to pass from mother to fetus
Which placenta is least efficient and why
cotyledonary (or diffuse) – more layers of nutrients have to travel between maternal blood and fetal blood
Rugae
Maternal Side of the placenta in pigs
Areola
Fetal Side of Placenta in Pigs
Cotelydon
Fetal Side of Placenta in cows
Caruncle
The maternal side of placenta in cows
What animals have diffuse placentas
horses and pigs
what animals have cotyledonary placentas
ruminants
What animals have zonary placentas
Carnivores
What animals have discoid placentas
Primates and rodents
Blastocoele
blastocyst cavity
trophectoderm
becomes fetal portion of placenta
Inner Cell Mass
Becomes fetus
How many layers does the zonary placenta have
Endotheliochorial
5 layers of tissue between the fetal and maternal blood supply
How many layers does a cotyledonary placenta have
Epitheliochorial
6 layers of tissue between the fetal and maternal blood supply
How many layers does the diffuse placenta have
Epitheliochorial
6 layers of tissue between the fetal and maternal blood supply
How many layers does a discoid placenta have
Hemochorial
3 layers of tissue between the fetal and maternal blood supply
How far along is a cow fetus if it feels like a mouse
2 months
How far along is a cow fetus if it feels like a rat
3 months
How far along is a cow fetus if it feels like a small cat
4 months
How far along is a cow fetus if it feels like a large cats
5 months
How far along is a cow fetus if it feels like a medium beagle sized dog
6 months
Ewe/Doe Gestation length
150 days or 5 months
cattle gestation length
282 days or 9 months
Sow Gestation Length
114 days, 3 months, 3 weeks and 3 days
Mare Gestation length
340 days-11 months
Mice Gestation length
21 days
Elephant Gestation Length
616 days or 2 years
What is the earliest an experienced palpator can detect pregnancy in cattle
28-30 days post insemination through feeling for the amniotic vesicle, the fetal membrane slip, or the fetus in the uterus.
An advantage of early pregnancy detection in cattle
-Can identify non pregnant cattle sooner and have the oppprtunity to get them re-bred quicker
Disadvantage of early pregnancy detection in cattle
Slipping of the amniotic vesicle during this early stage og pregnancy could disturb the implantaion resulting in pregnancy loss
Why do we palpate through the rectum as opposed to the vagina to detect pregnancy
If we palpate via the vagina we could rupture the cervical plug of pregnancy allowing for bacteria or pathogens to enter the into the uterine body, which could posibly terminate the pregnancy.
What substance is detected in the blood pregnancy test used for ruminants? What tissues produce this substance?
aPregnancy Specific Protein B (PSPB).
binucleated cells of the trophectoderm
Where is the milk produced and stored within the mammary gland
Produced in the Alveoli and stored in the glands cistern
What ligament forms a sling around the udder
Lateral Suspensory Ligament
What is the function of the streak canal
streak canal retains the milk in the udder against the pressure developed by the accumulation of milk and is also the main barrier against infection
What hormone inhibits milk letdown?
Catecholamines (epinephrine and norepinephrine)
What hormone stimulates milk letdown
oxytocin
Why is post-dip used on the udder after milking?
To help prevent mammary infection when the animals are returned to their living enviroment.
Describe the milk letdown response
- Stimulation of the teats send a nerve pulse from the mammary gland via the spinal cord to the brain.
- goes to the hypothalamus signaling release of oxytocin from the posterior pitutary into the capilaries
- The capilaries carry the oxytocin to the myo epithelial cell in the mammary gland.
Oxtocin binds to its receptor causing smooth muscle contractions forcing the milk from the aveoli through the lacteriferious ducts past the glands cistern and teat cistern and out of the gland.
Median Suspensory Ligament
divides the udder into right and left halves, and is located along the center of the udder, it can stretch as the gland fills with milk
Mammary Aveoli
Milk will be produced in cells that are grouped together in tiny storage units called alveoli
They appear as sac-like structures
They are lined with epithelial cells that produce milk
Gland Cistern
This is the largest storage area for milk
Located above the teat cistern at the base of the udder, it is separated from the teat cistern by the annular or cricoid fold
The gland cistern will fill rapidly during milk letdown
Teat Cistern
Holds 0.5 to 1.5 ounces of milk
This is where milk will accumulate before being removed through the teat end during milking
Continuously refills during milking
How long (total length of time) are sows in the farrowing barn at the Swine Education Unit?
1 month, (1 week prior to farrowing and then 21 days of nursing piglets)
What hormone is used to induce parturition in sows? Why
Lutalyse or Prostaglandin F2A, it removes the source of progesterone i.e. the CL
When is an animal culled from the breeding herd?
3 or Three strikes equaling being not pregnant after being bred 3 separate times
Sign a sow will exhibit prior to parturition
Udder development & presence of milk
Species variations in timing
Hollowing & relaxation
Flank, loin & tail head areas
Nesting
Isolation
Off feed
Colicky / discomfort
How many females farrow in a group
50
What are pigs that dies after day 100 called
stillborns
What are piglets that die between day 50 and 100 called
mummies and have been partially reabsorbed by the sow
At what days post insemination do the farm crew ultrasound females (sows and gilts) at the Swine Education Unit? Why are those days important in determining pregnancy
Farm crew scans at 35 and 56 days, At 35 days they would be able to see fluid filled uteri following the initial breeding. At 56 day this is the time that the animals would be returning into estrus.
Uterus on an ultrasound
– Dense gray circles looking like doughnut if open, dark fluid filled circles if pregnant
Follicles on an ultrasound
dark fluid filled circles
Bladder on an ultrasound
Large dark fluid filled object
Bone on an ultrasound
very bright objects
Preparatory Parturition Stage One
- Uterine contractions
- Rotation of the fetus
- Dilation of the cervix
Fetal Expulsion: Stage 2
*Chorioallantoisnruptures
-Water breaking
*Fetus forced through birth canal
-Abdominal and uterine contractions -Remains inside amnion
-Rupture of amnion
-Delivery of fetus
-Umbilical cord severed
Delivery of Membranes: Stage 3
-CHorionic Villi Loosen and Detach
-Afterbirth is shed
What Body Condition Scoring Scale is used at the NCSU Beef Unit?
Scale is 1-9 with 1 being emaciated and 9 being very obese, ideally we want cattle to be around a 5-6
At what temperture are sperm stored in a liquid nitrogen refrigerator.
-320 Farenheit
Why arent sperm cells destroyed in this extremely cold environment
Sperm cells are placed in an extender containing a cryopreservant, in addition the sperm are rapidly frozen which prevents the formation of ice crystals
What is the critical danger zone
This is the neck region of the liquid nitrogen refrigerator, where the temperature rapidly increases
At what temperature and for how long do we thaw a semen straw
Thaw semen at 95F (35C) for 30-45 seconds
What are the 6 main areas that we observe in cattle to determine a body condition score?
The six main areas we observe are the tail head, back, hooks, pins, ribs, and brisket
5) What is capacitation and why is it important
Capacitation is final maturation step of spermatozoa,it is a biochemical event that alters the sperm head,induces hypermotility and enables the sperm cell to attach and penetrate the egg
What is the volume and sperm concentration of an AI straw
The volume is 0.5 cc (mL) and 20 to 40 million sperm per straw
How does time and temperature impact semen quality post thaw
Changes in temperature either too cold or hot will kill the sperm, additionally We observed that sperm moltilty decreased over time post thaw
What species has the easiet semen to preserve
ttle, Dairy Cattle are the leading species where AI is used; therefore, a lot of research has been focusing on preserving cattle semen
What information can we find on a semen straw
AI Center code (1-312)
Bull’s Breed (AN)
Bull’s ID within AI center (100)
Cane and Goblet
A cane and goblet help keep the ampules and the straws organized
They also keep the straws from falling into the bottom of the liquid nitrogen refrigerator
Can also get canes with built in goblets
Goblet
unit that holds the semen straws
Primary abnormalities of sperm
head of sperm
-pear shape, slender, double head, micro or macro cephalic
Secondary Abnormalities Midpiece and Tail
Midpiece: kinked, double, swollen
Tail: coiled, cytoplasmic droplet
