雄猫の性成熟過程における造精能の発達 Development of Spermatogenic Function in the Sex Maturation Process in Male Cats
Access this Article
Search this Article
去勢を依頼された4ヵ月齢〜2歳齢の雑種猫180頭を用いて,性成熟過程の造精能およびplasma testosterone(T)値を観察した.その結果,精巣および精巣上体重量は,それそれ10ヵ月齢,8〜9ヵ月齢でピークに達した.精巣への精子の出現は,早いもので5ヵ月齢でみられ,7ヵ月齢で96.2%と,ほぼ全例に認められた.精巣上体尾部への精子の出現は,6ヵ月齢で46.9%で,8ヵ月齢以降は全例に認められた.また.plasma T値は,8ヵ月齢で急上昇し,10ヵ月齢で平均2.64土0.68(SE)ng/mlとピークを示した.なお,180頭中3頭(1.67%)は片側潜在精巣であった.以上の成績から,雄猫の造精能は,8〜10ヵ月齢で成熟するものと思われた.
The spermatogenic function and plasma testosterone (T) level in the sex maturation process were investigated as to 180 mixed breed cats ranging from 4 months to 2 years in age to be castrated. Testis/epididymis weights reached a peak at 10 and 8 to 9 months of age, respectively. In the testis, sperm appeared at 5 months of age. At 7 months of age, sperm were observed in 96.2% of the cats. In the tail of the epididymis, sperm appeared in 46.9% of the cats at 6 months of age and in all cats at 8 or more months of age. Furthermore, the mean plasma T level rapidly increased at 8 months of age, and reached a peak (2.64 ± 0.68 (SE) <i>n</i>g/m<i>l</i>) at 10 months of age. Three of 180 cats (1.67%) had unilateral cryptorchidism. These results suggest that the spermatogenic function in male cats becomes mature at 8 to 10 months of age.<br>
- Journal of Veterinary Medical Science
Journal of Veterinary Medical Science 66(9), 1125-1127, 2004-09-25
Japanese Society of Veterinary Science