Poultry Science- ICAR JRF/SRF 2024

• Rose Comb and Subfertility in Roosters:
• Homozygous Rose-comb cocks ($RR$) exhibit a well-documented genetic subfertility syndrome.
• The $R$ allele is associated with a chromosomal inversion that disrupts the sperm motility gene, resulting in abnormal flagellar function and extremely reduced duration of sperm motility in the oviduct storage tubules.

Correct option: (1) Rose comb

• Statement (I) is False: The magnum is the longest anatomical section of the avian oviduct (length $\sim 33\text{ cm}$), whereas the uterus (shell gland) measures only $10\text{ to }12\text{ cm}$.
• Statement (II) is True: In commercial chicken artificial insemination (AI), an insemination dose containing $20\text{ to }25\text{ million}$ motile spermatozoa administered weekly into the vagina achieves over $90\%$ fertility.
• Conclusion: Statement (I) is false, but Statement (II) is true.

Correct option: (4) Statement (I) is false but Statement ({I) is true.

• Sperm Nest $\to$ (IV) Infundibulum: Specialized tubular invaginations (sperm storage tubules / sperm nests) located in the infundibulum and uterovaginal junction store viable spermatozoa for up to 2–3 weeks.
• Cock Semen $\to$ (III) Alkaline: Normal rooster semen has an alkaline pH of $7.2\text{ to }7.6$.
• Ringer's Solution $\to$ (I) Semen Extender: Standard isotonic balanced salt solution used to dilute avian semen for artificial insemination.
• Shell Gland $\to$ (II) Uterus: The pouch-like segment where the egg resides for 20 hours for calcium carbonate shell deposition.

Correct option: (2) (A) - (IV), (B) - (III), (C) - (I), (D) - (II)