Reproductive Activity

Question 1

when do bovine hit puberty

Answer 1

11 months

Question 2

when do equine hit puberty

Answer 2

17 months M
18 months F

Question 3

when do ovine hit puberty

Answer 3

7 months

Question 4

when do porcine hit puberty

Answer 4

7 months M
6 months F

Question 5

when do canine hit puberty

Answer 5

9 months M
12 months F

Question 6

when do feline hit puberty

Answer 6

9 months M
8 months F

Question 7

what changes from the release of GnRH pre-puberty to during puberty

Answer 7

pre-pubity Steroid hormones inhibit GnRH (Negative Feedback)
during puberty steroid hormones cause a positive feedback - so an increase in GnRH release

Question 8

what does induced ovulation by exogenous GnRH show

Answer 8

that brain puberty is independent of gonadal puberty

Question 9

what occurs in the female during brain puberty

Answer 9

GnRH release inreases, so more LH is released, more follicle development, more oestrogen release with increases surge centre of GnRH
tonic centre become less sensitive to oestrogen

Question 10

how does light pass to the pineal gland

Answer 10

light in the retina passes to hypothalamus via retino-hypothalmic tract, then to super chiasmatic nucleus (SCN), then to Bilateral superior cervical ganglia, then pineal gland

Question 11

what is the function of the pineal gland, how is this important for reproduction

Answer 11

controls melatonin levels for body rhythms.
most melatonin is released in the dark, so more is released in the winter months.
hypothalamus is most sensitive to melatonin in the afternoon, so the body can sense when it is winter and therefore when to raise or decrease GNRH levels for fertility so offspring are born during spring/ summer in order to have higher nutrient and easily digestible grass.

Question 12

what can be given to decreas GnRH secretion

Answer 12

2-deoxyglucose
(puts body into fasting)