Exam #2 Review Flashcards
Unit #4
1
Q
What is Puberty
A
Puberty is the period during which teens reach sexual maturity and become capable of reproduction.
2
Q
What is Hormone Cascade
A
Produces each needed hormone by choosing different pathways
3
Q
Puberty depends on three things
A
on age, sex, and genotype
4
Q
Genotype
A
Internal Factor. Its a genetic factor that determines the onset of puberty
5
Q
High muscle-fat animals tends to reach puberty Sooner or later?
A
Sooner
6
Q
What is Genetic Variability?
A
The presence of genetic differences
7
Q
How is body weight crucial factor influencing puberty?
A
Having the right body weight means the body has the right amount of energy to start puberty at the right time.
8
Q
Heavy animals reach puberty sooner or later?
A
Sooner
9
Q
How does body condition influence puberty?
A
Our bodies need a certain amount of energy (from Food) to influence the puberty onset
10
Q
If the animal body has alot of energy stored as fat, the body….
A
The body will go into puberty sooner
11
Q
If the animal body does not have enough energy?
A
The body would wait longer to start puberty
12
Q
What is a internal factor and secondary factor?
A
Age
13
Q
Why is age a secondary factor in puberty onset?
A
It is influence by genetics
14
Q
What are the 4 external factors of puberty?
A
- Environmental Conditions
- Photoperiod
- Nutriton
- Socio-Sexual Interactions
15
Q
What is heat expenditures?
A
how our body uses energy to control temperature
16
Q
What is Photoperiod?
A
The duration of daylight hours influence melatonin
17
Q
what happens when a animal is in cold stress?
A
The energy expenditure increases to keep warm and their stored energy increases and their hormones changes will delay puberty
Example: Video games characters using “Warmth power ups” to stay warm, if they use too much they will have to find more power ups to level up (puberty).
If its too cold the hormones might delay puberty.
18
Q
A
19
Q
Is Photoperiod external or internal factor?
A
External
20
Q
Why is nutrition important for puberty?
A
sufficient quanity/quality leads to a positive energy balance.
21
Q
Is nutrition a internal or external factor?
A
external
22
Q
Why is Socio-sexual interactions positive for puberty?
A
The presence of males can stimulate sexual activity in females which leads to hormonal changes and potential earlier puberty
23
Q
what is male effect?
A
the presence of a male stimulating sexual activity in the female.
24
Q
What does HPG axis Stand for?
A
Hypothalamic-pituitary-gonadal axis
25
What is HPG axis?
hormone regulating mechanism that controls reproductive activity
26
What did Frish Theory highlight?
the importance of energy balance and body composition in the timing of puberty.
Light/Taller: later puberty
Short/fat: Sooner puberty
27
What is the primary driving force behind the onset of puberty?
The onset of puberty is primarily driven by a hormone cascade
28
What role does genotype play in puberty?
Genotype plays a significant role in determining the onset of puberty.
29
Provide an example of how breed affects puberty in livestock.
Saanen and Nubian goats have different weights and heights, despite having similar mature sizes, which affects their puberty onset.
30
How does litter size impact the timing of puberty?
Singletons attain puberty earlier than twins or triplets due to increased feed intake and growth factors.
31
Explain the relationship between body weight and puberty onset
Heavier animals generally reach puberty sooner.
32
What does body condition scoring (BCS) assess?
Body condition scoring (BCS) assesses the relative fatness or energy balance of livestock.
33
Why might singletons generally reach puberty sooner?
Singletons generally reach puberty sooner due to increased feed intake and growth factors.
34
How does heat stress affect puberty?
Heat stress can delay puberty due to increased energy expenditure, depleted fat stores, and hormonal changes.
35
What is the impact of photoperiod on puberty in spring-born lambs?
Spring-born lambs, exposed to longer daylight hours, attain puberty earlier.
36
Describe the effect of inadequate nutrition on puberty.
Inadequate nutrition can delay puberty due to a negative energy balance.
37
What is the "male effect" in the context of puberty?
The "male effect" refers to the stimulation of sexual activity in females due to the presence of males, potentially leading to earlier puberty. [
38
Which part of the brain secretes gonadotropin-releasing hormone (GnRH)?
The hypothalamus secretes gonadotropin-releasing hormone (GnRH)
39
What are the functions of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in puberty?
LH and FSH stimulate the gonads to produce sex hormones, leading to the development of secondary sexual characteristics and reproductive capabilities.
40
Which hormones do the gonads produce in response to LH and FSH?
The gonads produce sex hormones (estrogen or testosterone) in response to LH and FSH.
41
What is the primary source of the hormone leptin?
Leptin is primarily produced by adipose tissue.
42
How does leptin influence puberty onset?
Leptin signals the body's energy status to the brain, influencing puberty onset.
43
What is the main idea behind the Frisch Theory?
The Frisch Theory suggests that a critical body fat percentage is necessary for the onset of puberty in females
44
According to the Frisch Theory, shorter and heavier girls tend to experience puberty sooner True or False?
true
45
What is the role of melatonin in regulating seasonal reproduction?
Melatonin, influenced by daylight hours, plays a role in regulating seasonal reproduction
46
Name the internal factors influencing puberty.
The internal factors influencing puberty are genotype, liveweight, body conditon and "Age"
47
What is the estrus cycle?
a specific part of the estrous cycle. It is when the female is ready to mate with the male.
48
How many main phases is the estrous cycle divided into?
two
49
What are the two main phases in the estrous cycle
Follicular phase and Luteal Phase
50
What is the follicular phase?
Its where the body sends hormones telling the follicular to grow, as the follicular grows and ready to pop, a egg comes out.
The popping is "ovulation"
51
What does Peppy Elephants March Daily Across
Proestrus, Estrus (heat), metestrus, Diestrus, and anestrus
52
In most farm animals, if there's not pregnancy, the lining of the uterus is
reabsorbed
53
How does the farm animals reabsorbed the uterine lining?
The blood vessels shrink down, the cells break down and then reuse
54
The stages of the follicular phases are
proestrus and estrus
55
What does progesterone have to do with the estrous cycle?
helps build up the lining of the uterus, where the fertilized egg can settle and grow
Stops the estrus phase
Supports pregnancy
56
What stages are in the luteal phase?
metestrus and diestrus
57
when does ovulation occur?
right before the luteal phase
58
Luteal phase is about?
Getting ready for a baby and taking care of a pregnancy or resetting for next time
59
What is proestrus?
The preparation phase: Sending hormonal signals to get the eggs ready, preparing the uterus for the potential fertilized egg
follicles start to grow
60
what does follicles do?
hold the egg
61
What stage does follicles start to grow?
Proestrus phase
62
What makes progesterone?
Corpus lutem
63
Why does progesterone decrease during the proestrus cycle?
because this hormone’s primary role is to prepare and maintain the uterus for pregnancy after ovulation has occurred.
64
What happens during the Estrus phase?
the female is receptive to the male
65
How would one know if a female is in the estrus phase?
1. The cervix will produced clear/transparent mucus
2. inflammation of the vulva occurs
3. Estradoil is responsible for sexual behavior
66
This is the longest stage, and it involves pregnancy recognition
Dieestrus
67
Progesterone levels are high in this stage
Dieestrus
68
Metaestrus
The female is no longer receptive to the male
69
Metestrus
The body prepping for a baby
70
It winds down if no baby
Metestrus
71
Quiet time part of the cycle if no baby
Dieestrus
72
What is Estradiol?
Responsible for sexual behavior during estrus
73
What is Prostaglandin (PGF2a)?
a chemical messenger
73
increase from the uterus during the proestrus
Prostaglandin (PGF2a)
74
causes regression of the corpus lutem
Prostaglandin (PGF2a)
75
Monoestrous
Animals with one estrous cycle per year
76
Seasonally Polyestrous
Animals with cycles during a limited season
77
Continue polyestrous
animals with cycles throughout the year
78
Examples of monoestrous
Dogs, Wolves, and Foxes
79
Examples seasonally polyestrous
sheep, goats and mares
80
examples of continue polyestrous?
Cattle, pigs and rodents
81
What is the primary function of the estrous cycle in female animals?
To regulate female receptivity for mating.
82
Name the two primary phases of the estrous cycle.
Follicular Phase and Luteal Phase.
83
During which phase of the estrous cycle does follicular selection occur?
Follicular Phase
84
What is the key hormone responsible for the onset of estrus?
Estradiol.
85
Describe two behavioral changes in cows during estrus
Allows mounting by other cows, Increased urination frequency, Displays restlessness or agitation.
86
What is the primary function of the corpus luteum?
To produce progesterone, which prepares the uterus for pregnancy.
87
In which stage of the estrous cycle does the corpus luteum reach its full functionality?
Diestrus.
88
What hormone is responsible for the regression of the corpus luteum?
Prostaglandin (PGF2α).
89
What is the average duration of the estrous cycle in goats?
21 days (18-22 days).
90
How does the duration of estrus differ between cows and mares?
Cows: 4-24 hours; Mares: 5-7 days
91
What is a monoestrous cycle? Provide an example of an animal that exhibits this type of cycle.
One estrus cycle per year (e.g., dogs, wolves, foxes).
92
Explain how the estrous cycle ensures the optimal timing for mating and reproduction.
By coordinating hormonal changes and behavioral signals to ensure that the female is receptive to mating when an egg is ready for fertilization.
93
What triggers the release of FSH from the ovary, and what is its role in the estrous cycle?
A low pulse rate of gonadotropin-releasing hormone (GnRH) triggers FSH release, stimulating follicle growth and development.
94
What is reproductive seasonality?
When the animals chooses the "best" season to have babies.
Example: lots of food, and good weather
95
How does reproductive seasonality benefit seasonal breeders?
seasonal breeders aligning their cycle with the best season that can provide them with the best weather and best food source
96
What is the primary environmental factor influencing reproductive seasonality in small ruminants and equines?
is light, specifically the duration of daylight or photoperiod.
97
What is anestrus, and how does it relate to reproductive seasonality?
Anestrus is a period of temporary ovarian inactivity or reproductive rest
98
How does the pineal gland play a role in regulating reproductive seasonality?
is responsible for producing melatonin
99
Where is the pineal gland located?
The pineal gland, located in the brain
100
What is melatonin
a hormone that plays a crucial role in regulating seasonal reproductive cycles.
101
Explain the relationship between melatonin and reproductive activity in seasonal breeders.
Melatonin levels are inversely related to light exposure; longer periods of darkness increase melatonin secretion, which, in turn, influences reproductive activity in seasonal breeders
102
Besides light, what other factor significantly influences reproductive seasonality in farm animals?
the genotype of an animal significantly influences its reproductive seasonality.
103
Provide three examples of goat breeds known for their distinct reproductive seasonality.
Three goat breeds known for their distinct reproductive seasonality are Saanen, Alpine, and Toggenburg, originating from the French Alps.
104
What is the average gestational length in small ruminants? Why is this information relevant to understanding reproductive seasonality?
The average gestational length in small ruminants is approximately 5 months. This is important because it helps plan when the baby will be born and to make sure there is plenty of food and the weather is nice
105
List three key management practices influenced by an animal's reproductive seasonality.
timing of mating/breeding, planning for lambing/kidding, and adjusting nutritional programs to support the demands of pregnancy and lactation during specific seasons.
106
What are two methods used to manipulate night duration for out-of-season breeding?
using artificial lighting to extend daylight hours and simulating shorter days by keeping animals in darkness for specific periods.
107
Explain the objective of modifying night duration from November 1st to January 15th (16 hours of light and 8 hours of dark).
is to optimize the reproductive efficiency of males by the time they are needed for breeding.
108
How does the administration of melatonin implants affect reproductive activity in seasonal breeders?
by mimicking natural melatonin production, can manipulate reproductive activity in seasonal breeders, inducing estrus or enhancing reproductive responsiveness.
109
What is the role of progestogens in managing reproductive seasonality, particularly in females?
They can be used to synchronize estrus, terminate pregnancy, or re-activate sexual behavior in females, particularly during the non-breeding season.
110
What is stimulus quality?
how strong and effective the signals are to led to interactions that could lead to mating.
for example: depending on things like whether the male is around, how dominant he is, and how much of a scent he produces that can attract mates.
111
What is refractoriness?
time when the animals are not interested in mating signals
112
Why is it important to understand and manage reproductive seasonality in farm animals?
crucial for optimizing breeding efficiency, ensuring successful pregnancies, and maximizing the overall productivity and profitability of livestock operations
