ANSC 3040 QUIZ 2 QUESTIONS AND CORRECT ANSWERS
What is dependent for puberty? - answers - - maturation of the reproductive tract and
hpg axis
- genetics (species differences)
- environment (nutrition, health, social cues, and photoperiods)
How do we know if a male is fertile? - answers - 1) behavioural traits
2) first ejaculation
3) first ejaculation with spermatozoa
4) the ejaculate contains the correct threshold of sperm for fertilization
When is the male reproductive tract done forming? - answers - by day 125 in utero,
everything after is focused on maturing
What occurs when bulls are 25 woa? - answers - the lumination process which is the
significant growth of the seminiferous tubules
What is the importance of early bloomers in bulls? - answers - they have higher lh
secretions compared to later bloomers
What occurs from 0-5 weeks after being born for bulls? (think hormones) - answers - not
much gnrh, lh or testosterone present but an increasing responsivity of fsh secretion
What occurs from 6-15 weeks with the bull's hormones? - answers - - increasing
frequency of gnrh and lh
- fsh remaining at same levels
- low testosterone levels
- priming of leydig and sertoli cells
What occurs from 16-25 weeks of a bull's hormones? - answers - - gnrh, lh, and fsh
levels decrease
- testosterone remains low
- some growth of seminiferous tubules
-no spermatogenesis yet
What occurs from 26-45 weeks of the bull's hormones? - answers - - gnrh, lh, and fsh
levels increase
- testosterone levels increase dramatically
- proliferation and increased activity of leydig and sertoli cells
- big growth of seminiferous tubules
- spermatogenesis occurs here!
What occurs after 45 weeks of age? - answers - maturation of the reproductive tract
, - especially 4 weeks after puberty
What decreases for most males when puberty is reached? - answers - - time to mount
- total number of mounts
- time to erection
- time to ejaculation
How do genetics influence puberty? - answers - - early maturing breeds reach puberty
earlier than others
- maternal breeds reach puberty earlier than paternal breeds (milk vs meat production)
- note that there are variations in species
How is nutrition important for puberty? - answers - - the hypothalamus can sense the
nutritional status of the animal
- it also senses leptin, glucose and fas
- neurons will secrete gnrh to help the onset of puberty
Tl;dr: better fed animals reach puberty faster than others
What is important with metabolites and puberty? - answers - as the animal grows, the
body develops along with the adipose tissue and muscles until an animal reaches a
threshold for puberty
Why are social cues important in puberty? - answers - - pheromones are volatile
chemical compounds and are detected by olfactory senses
- some species are seasonal breeders
How can age of puberty affect an industry? - answers - the more of a population at the
correct age will increase supply for the industry
- especially industries that sell semen, embryos, etc.
What are the ways we are able to perform castration? - answers - - surgical
- elastic bands
- burdizzo clamps (ruminant only)
- immunocastration (swine only)
- chemical castration
Why do we castrate? - answers - - contraceptive method (pop. Control)
- reduction of sexual/ aggressive behaviour
- unpleasant smell removal (boars)
- meat properties (composition, marbling, and tenderness)
- health (tumors, severe lesions, etc.)
How does immunocastration work? - answers - vaccine will create antibodies against
gnrh and they cannot act in the pituitary
- this reduces lh and fsh = repro tract not developing
What is dependent for puberty? - answers - - maturation of the reproductive tract and
hpg axis
- genetics (species differences)
- environment (nutrition, health, social cues, and photoperiods)
How do we know if a male is fertile? - answers - 1) behavioural traits
2) first ejaculation
3) first ejaculation with spermatozoa
4) the ejaculate contains the correct threshold of sperm for fertilization
When is the male reproductive tract done forming? - answers - by day 125 in utero,
everything after is focused on maturing
What occurs when bulls are 25 woa? - answers - the lumination process which is the
significant growth of the seminiferous tubules
What is the importance of early bloomers in bulls? - answers - they have higher lh
secretions compared to later bloomers
What occurs from 0-5 weeks after being born for bulls? (think hormones) - answers - not
much gnrh, lh or testosterone present but an increasing responsivity of fsh secretion
What occurs from 6-15 weeks with the bull's hormones? - answers - - increasing
frequency of gnrh and lh
- fsh remaining at same levels
- low testosterone levels
- priming of leydig and sertoli cells
What occurs from 16-25 weeks of a bull's hormones? - answers - - gnrh, lh, and fsh
levels decrease
- testosterone remains low
- some growth of seminiferous tubules
-no spermatogenesis yet
What occurs from 26-45 weeks of the bull's hormones? - answers - - gnrh, lh, and fsh
levels increase
- testosterone levels increase dramatically
- proliferation and increased activity of leydig and sertoli cells
- big growth of seminiferous tubules
- spermatogenesis occurs here!
What occurs after 45 weeks of age? - answers - maturation of the reproductive tract
, - especially 4 weeks after puberty
What decreases for most males when puberty is reached? - answers - - time to mount
- total number of mounts
- time to erection
- time to ejaculation
How do genetics influence puberty? - answers - - early maturing breeds reach puberty
earlier than others
- maternal breeds reach puberty earlier than paternal breeds (milk vs meat production)
- note that there are variations in species
How is nutrition important for puberty? - answers - - the hypothalamus can sense the
nutritional status of the animal
- it also senses leptin, glucose and fas
- neurons will secrete gnrh to help the onset of puberty
Tl;dr: better fed animals reach puberty faster than others
What is important with metabolites and puberty? - answers - as the animal grows, the
body develops along with the adipose tissue and muscles until an animal reaches a
threshold for puberty
Why are social cues important in puberty? - answers - - pheromones are volatile
chemical compounds and are detected by olfactory senses
- some species are seasonal breeders
How can age of puberty affect an industry? - answers - the more of a population at the
correct age will increase supply for the industry
- especially industries that sell semen, embryos, etc.
What are the ways we are able to perform castration? - answers - - surgical
- elastic bands
- burdizzo clamps (ruminant only)
- immunocastration (swine only)
- chemical castration
Why do we castrate? - answers - - contraceptive method (pop. Control)
- reduction of sexual/ aggressive behaviour
- unpleasant smell removal (boars)
- meat properties (composition, marbling, and tenderness)
- health (tumors, severe lesions, etc.)
How does immunocastration work? - answers - vaccine will create antibodies against
gnrh and they cannot act in the pituitary
- this reduces lh and fsh = repro tract not developing
