Exam 3 Flashcards
(367 cards)
1
Q
How many sperm does the turkey produce compared to the boar?
A
Turkey: 9 billion /cc
Boar: 200 million/cc
2
Q
How much sperm does the rooster produce?
A
35,000 every second
3
Q
How long does it take the avian male to make sperm compared to the human?
A
Avian: 2 weeks
Human: 2.5 months
4
Q
Where are the paired testes located in poultry?
A
Within the body cavity near the backbone and kidneys
5
Q
What temperature are the testes maintained at in poultry?
A
Body temperature
6
Q
During the poultry breeding season, how can the testis size increase?
A
300-500 fold
7
Q
How much seminiferous tubules are there in each testicle?
A
Several miles
8
Q
How much of the hen’s daily energy intake is used to make an egg?
A
40%
9
Q
What percentage of the female’s weight are the eggs?
A
Between 2 and 25%
10
Q
How many eggs are laid in a clutch before the hen incubates them?
A
Between 1 and 23
11
Q
How many ovaries do most female birds have a maturity? Why?
A
One left ovary
Decreases weight for flight
12
Q
What does the ovary in birds produce?
A
Egg yolk
13
Q
What does the oviduct in birds produce?
A
Egg white and shell
14
Q
How long does it take for the egg shell to form?
A
20 hours
15
Q
How long does complete egg formation take?
A
25 hours
16
Q
How often do birds lay eggs?
A
Some almost every day (chickens)
Some once every 2-8 days (megapodes)
17
Q
What is the site of fertilization in poultry?
A
Infundibulum
18
Q
When is the egg fertilized?
A
Within 20 minuted of release from the ovary
19
Q
What does the magnum do in poultry?
A
Engulf the ovum in albumen (egg white)
20
Q
What does the isthmus form in poultry?
A
Shell membranes
21
Q
What does the shell gland do?
A
Creates the hard shell from calcium and adds the color
22
Q
How long is sperm stored in female birds?
A
Up to 90 days
23
Q
Where is sperm stored in female birds?
A
Sperm storage tubules by the shell gland
24
Q
What are storage tubules? How do they work?
A
Blind ended pockets
Last sperm in is the first one out
25
By the time the egg is laid, how many cells does the embryo have?
Over 20,000
26
How long is the female bird "pregnant" for?
25 hours
27
What are the layers of albumen? (5)
```
Outer thin
Firm
Inner thin
Chalaziferous
Chalazae
```
28
What are the layers of the shell? (3)
Cuticle
Spongy (calcareous) layer
Mammillary layer
29
What are the layers of the yolk? (5)
```
Germinal disk
Latebra
Light yolk layer
Dark yolk layer
Yolk membrane
```
30
What are the layers of the membrane? (3)
Air cell
Outer shell membrane
Inner shell membrane
31
What are the steps to fertilization? (7)
1. Mating occurs
2. Sperm enter oviduct and are stored in sperm storage tubules
3. Sperm travel to ovum
4. Sperm bind to perivitelline layer
5. Sperm digest a hole through the layer and enter via acrosome reaction
6. Many sperm enter egg around germinal disc region
7. Male DNA from one sperm and female DNA within yolk combine to form embryo
32
Does sperm capacitation occur in poultry?
No
33
What happens instead of capacitation in poultry?
Oviductal secretions remove carbohydrates and proteins from sperm-egg receptors to prepare sperm for acrosome reaction
34
What does sperm bind to?
Receptors on the perivitelline layer
35
What is chZPC?
A protein that is a key component in sperm binding to perivitelline layer
36
What is chZPC homologous to?
Mammalian zona pellucida glycoprotein ZP3
37
What is chZPC synthesized from?
Granulosal cells surrounding oocyte
38
What does the binding of chZPC do?
Initiates the acrosome reaction
39
Does one sperm or several sperm penetrate the perivitelline layer of the avian ovum?
Several
40
What does a fast block/vitelline block do?
Changes the electrical potential and prevents further sperm fusion to egg membranes
41
What is the slow block to polyspermy?
Zona reaction
42
What happens during the zona reaction to prevent polyspermy?
Enzymes cleave sperm receptors, removing sperm bound to them
43
Do the reactions/blocks occur in the chicken?
No
44
How long does it take for the baby bird to become fully developed and hatch?
21 days
45
What can unfertilized chicken and turkey eggs produce?
Male embryos that will hatch and reach sexual maturity
46
How many of the unfertilized eggs from a turkey develop embryos?
45%
47
How many of the 45% unfertilized eggs develop to sexual maturity?
1%
48
What 4 steps must be taken before the embryo attaches to the uterus?
1. Development within the confines of the zona pellucida
2. Hatching of the blastocyte from the zona pellucida
3. Maternal recognition of pregnancy
4. Formation of the extraembryonic membranes
49
What is an ootid?
The cell after fertilization when both pronuclei are present
50
What is an embryo?
An organism in the early stages of development after the pronuclei fuse
51
What is a zygote?
One cell with diploid chromosomes following fusion of pronuclei
52
Is a zygote an embryo?
Yes, but an embryo is not necessarily a zygote
53
What are cleavage divisions?
Series of mitotic divisions dividing the cells into 2, 4, 8, and 16 daughter cells
54
What are blastomeres?
The cells generated from cleavage divisions
55
What is a fetus?
Potential offspring that is still within the uterus, but old enough to be able to detect what species it is
56
What is a conceptus?
The product of conception that consists of the embryo, extraembryonic membranes, fetus, and placenta
57
What are the first 8 cells of an early embryo?
Totipotent
58
What is totipotent?
Each cell could give rise to a complete individual
59
What are identical twins from?
A two-celled embryo that divides independently
60
If an early embryo is cut in half and put back into a recipient, what can happen?
Both can develop into healthy individuals
61
What do all cleavages within the zona pellucida create?
More cells, but not more mass
62
What happens after each embryo gets to be about 32 cells?
Cells can no longer be counted individually
63
What stage of embryonic development is it when there are 32 cells?
Morula stage
64
What happens during the morula stage?
Cells on the inside of the embryo develop gap junctions that allow for communication
65
What do the outer cells develop?
Tight junctions
66
What are tight junctions?
Cell-to-cell adhesions
67
What do the tight junctions do?
Make the zona more permeable and fluid begins to enter the morula and form a blastocoele
68
What is a blastocoele?
A fluid-filled cavity
69
What happens when a distinct cavity is recognizable?
The embryo becomes a blastocyst
70
What are the distinct cell populations that form?
Inner cell mass
| Trophoblast
71
What is the inner cell mass from? What does it form?
From the inside group of cells
| Forms the body of the embryo
72
What is the trophoblast from? What does it form?
From outside group of cells
| Forms chorion
73
As the blastocoele continue to accumulate fluid, what happens inside the zona?
Pressure increases
74
What do enzymes released from the trophoblast do?
Weaken the zona
75
What happens once the zona cracks open?
Blastocyst hatches
76
What is the blastocyst like in the cow and ewe on day 13?
3 mm in diameter
77
What is the blastocyst like in the cow and ewe on day 17?
250 mm in length
78
What is the blastocyst like in the cow and ewe on day 18?
Occupies both uterine horns
79
What is the blastocyst like in the pig on day 10?
2 mm spheres
80
What is the blastocyst like in the pig within 48 hours after day 10?
Grows to 200 mm in length
81
What is the blastocyst like in the pig on day 16?
1000 mm in length
82
What are the 2 groups of embryos?
Long preattachment period
| Short preattachment period
83
Which animals have a long preattachment period for embryos?
Most domestic animals
84
How long is the long preattachment period within the uterus?
Several weeks
85
When do extraembryonic membranes form in long preattachment?
Before attachment
86
Which animals have a short preattachment period for embryos?
Primates
87
What happens during short preattachment shortly after entering the uterus?
Embryo implants
88
When do extraembryonic membranes form in short preattachment?
After attachment
89
What are the extra embryonic membranes? (4)
Yolk sac
Chorion
Amnion
Allantois
90
In pigs, sheep, and cows, what do blastocysts become?
Filamentous or threadlike
91
In horses, what do blastocysts become?
Remain spherical
92
What must occur in order for maternal recognition of pregnancy to happen?
Luteolysis must be prevented
| Progesterone must be maintained
93
What is maternal recognition of pregnancy?
When the female recognizes she is and pregnant and sends a signal to block luteolysis
94
In the cow and ewe, what is the signal for maternal recognition of pregnancy?
Glycoprotein Interferon tau
95
What are interferons produced by? (4: * the one we care about)
Leukocytes
Fibroblasts
Lymphocytes
Trophoblastic cells*
96
When is interferon tau present in the uterus of the ewe and cow?
About day 13
97
Does INF-τ affect CL?
Not directly
98
What does INF-τ do?
Inhibits oxytocin receptors
| Promotes protein synthesis by uterine glands
99
What are 2 major differences between sow compared to the the cow and ewe for maternal recognition of pregnancy?
1. Conceptus produces estradiol that serves as the signal of pregnancy
2. PGF2α is produced, but is rerouted into uterine lumen due to the estradiol
100
What does E2 do for maternal recognition of pregnancy in the sow?
Increases contractions which distributed the conceptuses around the uterine horns
101
In the sow, how many conceptuses must be present to maintain pregnancy?
2 in each horn
102
In maternal recognition of pregnancy for the mare, what must the conceptus do?
Migrate within the uterus from one horn to the other
103
How many times and when does the migration of the conceptus in the mare occur?
12-14 times per day
| Day 12-14 of pregnancy
104
What does the migration of the conceptus in the mare do?
Inhibits PGF2α
105
Why is the conceptus migration necessary?
It does not elongate, so pregnancy recognition factors must be spread around
106
What have embryos in eutherian mammals evolved to do?
Attach and form a relationship with the uterus to ensure adequate nutrition and protection
107
What species does implantation occur in?
Rodents and humans
108
What is implantation?
When the embryo buries itself
109
What is the placenta?
A transient organ of metabolic interchange between the conceptus and the dam
110
What kind of organ is the placenta classified as? Why?
Endocrine organ
| Produces a variety of hormones
111
What is the chorion?
The fetal component of the placenta
112
What is the uterine endometrium?
The maternal component of the placenta
113
What does the fetus initiate? How?
Parturition
| By endocrine events that promote contractions, dilation of cervix, and expulsion of fetus and extraembryonic membranes
114
What is chorionic villus?
Finger-like projections on the surface of the chorion that protrude toward the uterine endometrium
115
How can placentas be classified? (2)
Distribution of chorionic villi
| Number of tissue layers separating maternal and fetal blood
116
What are the 4 types of placentas?
Diffuse
Zonary
Discoid
Cotyledonary
117
What species have a diffuse placenta?
Pigs and horses
118
What is the diffuse placenta like in pigs?
Velvet-like surface with many closely spaced chorionic villi distributed over the enter surface of the chorion
119
When does attachment occur in the diffuse placenta of the pig?
Day 12 after ovulation
120
What is the diffuse placenta like in the mare?
Microscopic microzones of chorionic villi (microcotyledons)
121
What else does the mare placenta contain?
Endometrial cups
122
What are endometrial cups?
Discrete areas of both trophoblastic and endometrial origin
123
When do endometrial cups develop?
Between days 35 and 60 of gestation
124
When are endometrial cups sloughed off?
After day 60 of gestation
125
What do endometrial cups produce?
Equine chorionic gonadotropin (eCG)
126
When does attachment occur in the diffuse placenta of the mare?
Day 24
127
What species have a zonary placenta?
Dogs and cats
128
What are the 3 regions of the zonary placenta?
A prominent region of exchange that forms a broad zone around chorion
A second region (paraplacenta) that consists of a highly pigmented zone containing blood clots
The transparent zone at the ends of the chorion that absorbs material from the uterine lumen
129
What species have a discoid placenta?
Primate and rodents
130
What is a discoid placenta?
One or two distinct discs that contain chorionic villi that interface with the endometrium and provide exchange for nutrients and waste
131
What animals have a cotyledonary placenta?
Ruminant animals
132
What is a cotyledon?
A placental unit of trophoblastic origin consisting of abundant blood vessels and connective tissue
133
What is the placentome?
The place of interface that consists of the fetal cotyledon and the maternal cotyledon
134
Where does the fetal cotyledon come from?
Chorion
135
Where does the maternal cotyledon come from?
Caruncular regions in the uterus
136
How many placentomes are in sheep? Cattle?
90-100
| 70-120
137
What does the chorion initiate in cotyledonary placentas?
Attachment to the caruncles of the uterus
138
Prior to the attachment to caruncles, what type of placenta is the cotyledonary placenta?
Diffuse
139
As gestation progresses, what happens to cotyledons?
The increase in diameter to increase surface area
140
If there are fewer layers in a placenta, that is the relationship like?
More intimate
141
What does the prefix of the word describing placental classification by layers describe?
Maternal side
142
What does the suffix of the word describing placental classification by layers describe?
Fetal side
143
What are the 4 different types placentas classified by layer?
Epitheliochorial
Syndesmochorial
Endotheliochorial
Hemochorial
144
How many layers are in the epitheliochorial placenta?
6
145
What animals have a epitheliochorial placenta?
Sow
| Mare
146
What is the epitheliochorial placenta?
Least intimate type
| Placenta and endometrium have an intact layer of epithelium
147
How many layers are in the syndesmochorial placenta?
6
148
What animals have a syndesmochorial placenta?
Ruminants
149
What is the syndesmochorial placenta?
Epithelium erodes and the regrows
150
What is unique to the syndesmochorial placenta?
Binucleate giant cells
151
How much of the syndesmochorial placenta is made up of binucleate giant cells?
20%
152
What do binucleate grant cells do?
Invade endometrial epithelium and transfer complex molecules from fetal to maternal placenta
153
What do binucleate giant cells secrete?
Placental lactogen
| Pregnancy specific protein B
154
What do binucleate cells produce?
Progesteron
| Estrogen
155
How many layers are in the endotheliochorial placenta?
5
156
What animals have a endotheliochorial placenta?
Dogs and cats
157
What is the endotheliochorial placenta?
Complete erosion of the endometrial epithelium
| Maternal capillaries are directly exposed to epithelial cells of the chorion
158
How many layers are in the hemochorial placenta?
3
159
What animals have a hemochorial placenta?
Primates and rodents
160
What is the hemochorial placenta?
Most intimate type
| Chorionic epithelium in direct apposition to maternal pools of blood
161
In a hemochorial placenta, how are nutrients and gases exchanged?
Directly from maternal blood
162
Look at pages 296-299 and 300-301 for pictures of different placenta types
Look at pages 296-299 and 300-301 for pictures of different placenta types
163
What does placental exchange involve?
Simple diffusion
Facilitated diffusion
Active transport
164
What is simple diffusion?
Gases and water pass from high concentration to low concentrations
165
What is facilitated diffusion?
Specific carrier molecules transport glucose, amino acids, etc.
166
What is active transport?
Ion pumps for sodium and potassium
167
What is the major source of energy for the fetus?
Glucose
168
Where is a majority of the glucose for the fetus derived from?
Maternal circulation
169
What can happen near the end of gestation due to the fetus' needs?
It can drain the maternal supply
170
When the maternal supply is drained, what happens? Why?
Ketosis
| Dam begins to metabolize fat with generate ketones for energy
171
What is ketosis common in?
Dairy cows
172
What does not cross the placental barrier? (3)
Maternal proteins
Lipids
Large peptide hormones
173
What does cross the placental barrier? (5)
```
Smaller peptides
Vitamin and minerals at variable rates
Many toxic substances
Many drugs
Microorganisms, pathogens, and viruses
```
174
What is teratogenic?
Inducing abnormal development from certain substances
175
What can hormones produced by the placenta do? (4)
Stimulate ovarian function
Maintain pregnancy
Influence fetal growth
Stimulate mammary function
176
What does eCG do?
Act as luteotropin and stimulates maintenance of the CL
| Promotes development of supplementary CL
177
When is eCG produced?
At time of attachment
178
When does eCG perform its function?
Betweens days 40 and 70 of gestation
179
What is human chorionic gonadotropin produced by?
Trophoblastic cells
180
When is hCG secreted?
When blastocyst hatches from the zona pellucida
181
When can hCG be detected in urine?
As early as day 8-10 of pregnancy
182
What does hCG bind to? What does that do?
LH receptors
| Increases P4 production
183
What does a progesterone block do?
Inhibits myometrial contractions
184
What does P4 stimulate?
Secretion by endometrial glands
185
In the ewe, mare, and human, is the CL necessary for all of gestation? Why?
No
| Placenta takes over production of P4
186
In the sow and rabbit, is the CL necessary for all of gestation?
Yes
187
In the cow, is the CL necessary for all of gestation?
It is needed for most, but could be removed at the end of gestation
188
What is estrogen produced by? When?
Placenta
| The last of part of gestation
189
What does the peak of estrogen in most species signal?
Early preparturient period
190
What is placenta lactose found in? (4)
Rodents
Sheep
Cows
Humans
191
What is placental lactogen similar to?
Growth hormone
192
What does placental lactogen do?
Promote growth of fetus
| Stimulates mammary gland of dam
193
What is relaxin produced by?
Placentas
| Ovary
194
What animals is relaxin produce in? (7)
```
Humans
Mares
Cats
Dogs
Rabbits
Pigs
Monkeys
```
195
What does relaxin do?
Softens connective tissue and allows muscles to stretch
196
Near the end of gestation, what happens to the fetus?
It becomes stress and the fetal anterior pituitary release adrenal corticotropin (ACTH)
197
What is ACTH?
A peptide hormone that stimulate the fetal adrenal cortex to produce corticoids
198
What do the corticoids do?
Initiate a cascade of events that cause changes in the endocrine condition of the dam
199
What 2 major events do endocrine changes in the dam cause to occur?
Removal of progesterone block
| Increased reproductive tract secretions
200
What are the 3 stages of parturition?
Initiation of myometrial contractions
Expulsion of the fetus
Expulsion of the fetal membranes
201
What does fetal cortisol promote?
Synthesis of 3 enzymes that convert P4 to estradiol
202
What do fetal corticoids cause to the placenta to do?
Synthesize PGF2α
203
What happens as E2 and PGF2α increase?
The myometrium becomes more active and contractions begin
204
As pressure inside the uterus increases, what happens to the fetus?
It rotates
205
Where should the front feet and head be positioned at?
Posterior of the dam
206
What will result if the fetus is not in the proper position?
Dystocia
207
What happens to E2, PGF2α, and contractions at the end of stage 1?
They all continue to increase
208
What does the fetus do at the end of stage 1?
Begins to push toward the cervix, applying pressure on the cervix
209
What do pressure-sensitive neurons in the cervix do at the end of stage 1?
Cause neural response and oxytocin release from the hypothalamus
210
What does oxytocin cause at the end of stage 1?
Contractions to increase and the fetus moves into cervical canal
211
What other hormone is important in the movement of the fetus to the cervical canal?
Relaxin
212
What does stage 2 of parturition do?
Initiates secretory activity of the reproductive tract
213
What is produced during stage 2? What does it do?
Mucus
| Washes out the cervical seal of pregnancy and lubricates the cervical canal and vagina
214
In stage 2, what do the fetal head and front legs do?
Put pressure on fetal membranes, rupturing them
215
Other than mucus, what lubricates the birth canal?
The loss of amniotic and allantoic fluid
216
What happens as the fetus enters the brith canal? What does this cause?
It is deprived of oxygen
| Promotes the movement of the fetus causing more contractions
217
What in the dam is important in expulsion of the fetus?
Abdominal contractions
218
What does the expulsion of fetal membranes require?
The chorionic villi must become dislodged from the crypts of the maternal side
219
What assets with the chorionic villi becoming dislodged?
Vasoconstriction of arteries in the villi
220
What is important during stage 3 in species with a hemochorial placenta?
Vasoconstriction on the maternal side
221
What are some causes of dystocia? (3)
Abnormal presentation (26% of all dystocia in beef)
Excessive size of fetus (46% in beef)
Multiple births in monotocous species
222
What can be some problems with multiple brits in monotocous species? (3)
Both twins may present simultaneously
First fetus is abnormal and blocks the second
Uterus experiences fatigue due to sustained contractions
223
What is dystocia a major cause of?
Fetal death
224
what does dystocia increase the chances of?
Retained placenta
225
What happens to postpartum estrus due to dystocia?
Delayed
226
What happens to fertility due to dystocia?
Decreases
227
What happens to calving interval due to dystocia?
Increases
228
What body weight should cattle be before breeding? Sheep?
55% of mature weight
| 65% of mature weight
229
What can induced parturition be used for?
Facilitate close observation
230
What does induced parturition do?
Shortens gestation and generation interval
231
What can be a result of induced parturition?
Large fetuses
232
What is used to induce parturition?
PGF2α and/or corticoids
233
What is the gestation length of cows?
9 months
234
What is the gestation length of ewes and goats?
5 months
235
What is the gestation length of mares?
11 months
236
What is the gestation length of sows?
3.8 months
237
What is puerperium?
The period after parturition when the reproductive tract returns to its non-pregnant condition
238
What is lactation?
Synthesis, secretion, and removal of milk from the mammary gland
239
What is the goal during puerperium?
To restore reproductive function
240
What are the 4 major events of the puerperium?
1. Myometrial contractions and expulsion of lochia
2. Endometrial repair
3. Resumption of ovarian function
4. Elimination of bacterial contamination of the reproductive tract
241
What do the myometrial contractions after parturition serve to do? (3)
1. Facilitate discharge of fluids and tissue debris from uterus
2. Compress the uterine vasculature and help minimize the possibility of hemorrhage
3. Reduce the overall size of the uterus
242
What does suckling do?
Induces the release of oxytocin, which induce contractions
243
What is lochia?
Bloody discharge expelled from the vulva
244
What does lochia contain?
Remnants of fetal placenta and endometrial tissue
245
When does lochia increase in dairy cows?Why?
Between days 5 and 10 postpartum
| Sloughing of caruncles
246
When does lochia end in cows?
By days 14-18
247
Is bacterial contamination of the uterus normal? Why?
Yes
| The warm, wet environment after parturition provides a good environment
248
What is bacteria removed with?
Lochia
249
What does high estradiol do for bacterial contamination?
Increase leukocytes, so the immune response removes bacteria
250
When can uterine infection occur?
When high number of bacteria overwhelm the natural defense mechanism
251
What can increase the incidence of uterine infection? (3)
Retained fetal membranes
Dystocia
Weak myometrial contractions
252
What can a uterine infection cause? (2)
Prolonged involution
| Delay in subsequent pregnancies
253
What is the most affective way to get rid of an infection?
Return to cyclicity
254
What is an economical reason to determine pregnancy?
A female that is not pregnant costs money to feed and house, but is not contributing to income
255
How can you save money on an animal after determining that she is not pregnant?
The earlier you discover that she is open and sell her, the less money you waste
256
Other than selling, why might a producer determine that an animal is open?
So they she can be submitted to a second AI
257
What else can determining pregnancy be used for?
Management strategy
258
What are 5 ways to determine pregnancy in cattle and when can they be done?
```
Palpation per rectum (day 35)
Ultrasonography per rectum (day 28)
Milk progesterone (days 18-24)
Blood progesterone (days 18-24)
Pregnancy specific protein B (day 26)
```
259
What are 5 ways to determine pregnancy in a ewe and doe and when can they be done?
```
Ultrasonography per rectum (day 28)
Milk progesterone (days 18-2
Blood progesterone (days 18-24)
Vaginal biopsy (day 40)
Pregnancy specific protein B (day 26)
```
260
What are 6 ways to determine pregnancy in horses and when can they be done?
```
Palpation per rectum (day 35)
Ultrasonography per rectum (day 28)
Milk progesterone (days 18-2
Blood progesterone (days 18-24)
Equine chorionic gonadotropin (day 40)
Estrone sulfate (day 70 up to 2 weeks prior to foaling)
```
261
What are 3 ways to determine pregnancy in swine?
Return to estrus
Abdominal ultrasonography
Blood progesterone
262
What does BioPRYNes for equine do? How much does it cost?
Measures estrone sulfate in blood via ELISA
| $25
263
What does BioPRYN for cattle do? How much does it cost?
Measures pregnancy specific protein B in blood via ELISA
| $2.50
264
What does BioPRYN for sheep and goats do? How much does it cost?
Measures pregnancy specific protein B in blood via ELISA
| $6.50
265
What are 3 suggestive palpable signs of pregnancy?
Increase in size of one horn
Presence of fluid
Presence of function CL
266
What are 3 positive palpable signs of pregnancy?
Fetal membrane slip
Presence of amnionic vesicle
Presence of placentomes
267
What is a pro to palpation compared to blood?
You know much quicker if the animal is pregnant
268
When can you find the fetal membrane slip?
At 35 days
269
How can you find the fetal membrane slip?
Palpation of the fetal membranes
| Place widest part of thumb between thumb and forefinger and slide up
270
When do cotyledons begin to appear?
Around 100-120 days
271
What is not a good method of determining stage of pregnancy? Why?
Placentome
| Size varies
272
What does the ultrasound transducer do?
Acts to send and receive sound waves
273
How are sound waves created by the transducer?
Crystals that vibrate
274
What does a fluid look like on an ultrasound?
Black because there is no image
275
What is bone like on an ultrasound?
Reflects sound waves because it is the most dense tissue, so it is white
276
What do other tissue look like on an ultrasound?
Various shades of gray
277
What is the earliest someone could detect pregnancy?
Day 22, but day 30-35 for a more positive diagnosis
278
What are some advantages do ultrasound? (6)
Pregnancy can be detected earlier the palpation
Direct manipulation of the gravid tract is unnecessary
More accurately measure age
Detect fetal sex
Detect infections of uterus
View ovarian structures
279
What has artificial insemination been deemed?
The single most important physiological technology devised for acceleration of genetic improvement
280
What was the first reported use of AI?
In 1300 by Arabian horse breeders
281
What was the first documented report of successful AI?
In 1780 in Italy with dogs
282
Where did AI in cattle begin?
Russia
283
What are the steps of AI? (3)
Collect of semen from the male
Preservation and extension of sperm
Insemination of female
284
How many dairy cows are AI'ed?
7 million per year
285
How many beef cows are AI'ed?
2 million per year
286
How many turkeys are AI'ed?
All–300 million
287
How many sows and gilts are AI'ed?
75%
288
Describe commercial semen compared to custom collection (6)
```
More stringent guidelines on bull care and semen quality
Better gurantee
Beteer EPD information
More expensive
Sexed seme is an option
Other products besides semen
```
289
Describe custom collection compared to commercial semen (6)
```
Eliminates middle man
Reduced cost
More profit goes to bull owner
Producers can maintain ownership
More risk when buying semen
No extras
```
290
What must be determined to properly dilute sperm? (3)
Volume of ejaculate
Concentration of sperm
Percent motile sperm
291
What percentage is good for motile sperm?
60%
292
How can you calculate the total amount of sperm?
ejaculate volume x sperm/mL
293
What does knowing the total number of sperm in the ejaculate allow for?
The determination of the number of doses
294
How many units of sperm can bulls produce?
200,000 each year
295
How many units of sperm can boars produce?
1,500 to 2,000 each year
296
What are seminal extenders used to do?
Preserve sperm
Extend the lifetime of sperm
Extend the number of sperm
297
Why must extenders be isotonic?
So that water neither moves into or out of the sperm cell
298
What must extenders be? Why?
Good buffers
| Reduce the change in pH
299
What are cryoprotectants used for?
As protection against cold damage
300
When letting the seminal extenders temperature decline, what rate do a bull and stallion require?
Slow decline
301
What do sperm use for energy?
Fructose and glucose
302
Why must antibiotics be added to an extender? (3)
Ejaculated same is not sterile
Bacteria is present of penis and sheath
Seminal plasm and extender are ideal for microbial growth
303
At what temperature do most species prefer short-term storage to be? Swine
5ºC (near freezing)
| 18ºC
304
What does long term storage of semen require?
Freezing in liquid nitrogen and specific thawing techniques
305
What does freezing and thawing do?
Comprises viability and fertility
306
What does sperm contain?
An X or Y chromosome to determine sex of the embryo
307
What drives the desire to separate sperm by sex?
Either sex has a significantly more economic value in some production settings
308
What are some disadvantages to sexed semen? (5)
```
Expensive equipment
Slow rate of separation
Damage to sperm
Few bulls available
Semen sold in smaller doses
```
309
What kind of insemination is used in cattle? Where is semen deposited?
Transcervical
| Uterine body
310
What kind of insemination is used in swine? Where is semen deposited?
Intracervical
| Cranial cervix
311
What kind of insemination is used in dogs and cats? Where is semen deposited?
Intravaginal
| Vagina
312
What method is used to inseminate cows?
Recto-vaginal method
313
Which animal is insemination the easier in?
Sow
314
How much semen is used in pigs?
80 mL
315
How much semen is used in horses?
50 mL
316
What are reasons to use estrus synchronization? (5)
Establish pregnancy in all females in all females on the 1st day of breeding season
Increase number of opportunities to breed
Advances calving season and increases days at postpartum
Uniform calf crop
Facilitate AI
317
What 4 hormones are used to synchronize estrus?
Progesterone
Gonadotropin releasing hormone
Prostaglandin F2α
hCG and eCG
318
How can be P4 given?
Orally (Melengestrol acetate–MGA)
| Intravaginally (Controlled Internal Drug Release–CIDR)
319
What will happen with the administration of P4?
The animal will not ovulate
320
What will happen with the removal of P4?
The group will into estrus about the same time
321
What can progesterone also do?
Jumpstart anestrous animals into cycling
322
What is an injection of GnRH used to do?
Induce ovulation
323
In order for GnRH to induce ovulation, what must be present on the ovary?
A large enough follicle
324
What does PGF2α do?
Regresses the CL
325
What must be present for PGF2α to have any effect?
A functional CL
326
What is the oral progesterone used in mares and swine?
Alternogest
327
Look at protocols! Know why hormones are given when they are and some pros and cons of each protocol when compared to another
Look at protocols! Know why hormones are given when they are and some pros and cons of each protocol when compared to another
328
What are some advantage to embryo transfer? (5)
Circumvention of seasonal reproduction
Enhanced generation of offspring
Assisted reproduction for infertility
Enhanced reproductive potential of endangered species
Enhanced genetic diversity across a wide region
329
What is superovulation used to do?
Increase the potential offspring from a donor animal
330
What is superovulation due to?
An abnormally high number of follicles that are selected followed by ovulation
331
What does superovulation require?
Administration of exogenous gonadotropins
332
In superovulation, what percentage of the cows respond by producing one or fewer viable embryos?
30%
333
In superovulation, what percentage of the cows will produce as many as 30 embryos?
2%
334
How can oocytes be recovered? (3)
Surgically exposing ovary and aspirating follicles
Non-surgically aspirating follicles with ultrasonography
Aspirating follicles postmortem
335
How is fertilization completed after oocytes are collected?
in vitro
336
When can recipient females be set up to receive embryos?
At the time they are flushed (fresh transfer) or later (frozen transfer)
337
What must the recipients estrous cycle be like when flushed?
At the same point as the donor's
338
What day of her cycle must the recipient be on? Why?
Day 7
| Flushing usually occurs on day 7
339
What is the practical application of IVF?
Quickly multiple genetics of the best cow with the best bull
340
What is the research application of IVF?
Convenient way to study early embryo
341
What are some disadvantages to IVF? (4)
Expensive
Technical
Non-efficient
Sensitive process
342
What are the 3 steps to in vitro fertilization?
Maturation
Fertilization
Culture
343
What is intracytoplasmic sperm injection (ICSI)?
A singe sperm is placed directly into cytoplasm of oocyte
344
What does ICSI work well in? What is it limited in?
Humans
| Livvestock
345
What was ICSI developed to do?
Overcome fertility problems with the male
346
What are the 3 methods of cloning?
Embryo splitting
Nuclear transfer
Cloning using somatic cells
347
What is the most common method of cloning in production?
Embryo splitting
348
What decreases the viability of an embryo?
Further divides than being split in half
349
What is nuclear transfer?
The nucleus of an unfertilized oocyte is removes and cells from a trophoblast cell are placed in the enucleated cell
350
What method of cloning was used for Dolly the sheep?
Cloning by somatic cells
351
What are some anatomical abnormalities that are reproductive failures? (7)
```
Freemartinism
Underdeveloped reproductive system
Incomplete structures
Hermaphrodite
Cryptorchid
Injuries
Vaginal or uterine prolapse
```
352
What is an example of physiological abnormalities?
Cystic ovaries
353
What are follicular cysts?
When the follicle get large, but do not ovulate
354
What are luteinized follicles?
When the follicles become covered in luteal tissue even though they did not ovulate
355
What is a cystic CL?
A large fluid-filled cavity in the CL
356
What is the embryonic period?
Conception to the end of differentiation (day 45)
357
What is the fetal period?
Day 45 to delivery
358
What is early embryonic loss?
Loss before day 24
359
What is late embryonic loss?
Loss between day 24 and day 42-50
360
What is pregnancy loss?
Greater than day 50
361
What has a major impact on fertilization?
Heat stress
362
Why is there reduced fertility in negative energy balance?
Reduced embryo quality and viability
363
How much of all pregnancies are lost in high producing dairy cows?
60%
364
What factors can influence embryonic loss? (9- name a few)
```
Oocyte quality and persistent follicles
Progesteron and uterine environment
Maternal recognition of pregnancy
Heat stress
BCS
Cycling status
Dietary ingredients
Sire
Diseases
```
365
What are persistent follicles?
Old follicles that if ovulated have decrease fertility
366
What is a dietary ingredient that can cause problems? (3)
Gossypol in cottonseed
Mycotoxins produced by molds
Various vitamin and mineral deficiencies
367
What do high environmental temperatures do? (3)
Decrease viability of oocytes
Reduced oocyte quality
Reduced fertilization rate
