The time period of events of courtship and copulation in horses... | Agrigyan

• Unique Endocrinology of the Bitch (Canis lupus familiaris):
• In most domestic mammals (cow, ewe, mare, sow), luteinization of follicular granulosa cells occurs strictly post-ovulation under the influence of the LH surge.
• In the Bitch:
• Follicular granulosa cells undergo extensive pre-ovulatory luteinization $24 - 48\text{ hours}$ before ovulation in response to the initial rise in baseline LH.
• This causes circulating plasma progesterone levels to rise significantly ($\gt 2\text{ ng/ml}$) prior to follicular rupture, serving as the definitive clinical indicator for timing breeding and artificial insemination.
• nalysis:
• (Bitch): Correct.

Correct option: (4) Bitch

• Bovine Freemartinism:
• Occurs in over $90\%$ of heterosexual twin pregnancies in cattle.
• Early chorionic vascular anastomoses allow sharing of fetal blood circulation between the male and female co-twins.
• Testicular hormones from the earlier-developing male fetus (Anti-Müllerian Hormone [AMH] and testosterone) enter the female co-twin's circulation:
• Müllerian ducts regress, preventing normal development of the uterus, cervix, and cranial vagina.
• The female co-twin is rendered permanently sterile (Freemartin).
• The male co-twin develops normal reproductive tracts and is typically fertile.
• nalysis:
• (Female is sterile): Correct.

Correct option: (2) Female is sterile

• Blom's Classification of Sperm Defects:
• Primary Abnormalities: Arise in the testis during spermatogenesis:
• Double head, microcephalic/macrocephalic head, piriform head.
• Double midpiece, coiled tails, abaxial attachments.
• Secondary Abnormalities: Arise after leaving the seminiferous tubules (in the epididymis or during ejaculation/laboratory smearing):
• Detached normal heads (decapitated sperm).
• Distal cytoplasmic droplets, bent tails.
• nalysis:
• (Detached normal head): Correct (this is a secondary abnormality, not primary).

Correct option: (4) Detached normal head