"Hirosima" method of artificial insemination of the domestic Fowl

にわとりの人工授精の実用化を目ざして，技術上の改善を行なった.
1. 精液の採取にはマッサージ法を応用したが，従来のものと異なり鶏体保定台と精液受容器の新型を創案し，これを応用した.
2. この方法によると精液を質量共に最も自然に近い状態で， しかも，半無菌状態で回収できる.
3. 精液注入技術に対しては，注入管を約10cm 延長して，深部注入を可能にし，腟内注入と共に子宮内注入を可能にした.
4. 多数実験の結果，若干の熟練は要するが，子宮内出入が腟内注入よりも，高い受精率を示し，しかも，爾後の産卵率にも悪影響のないことを知った.
5. にわとりの精子は射精後，中片部で屈折して，いわゆる首曲り現象を起こし，これが卵子の受精率を著しく減殺することを確かめたので，その防止策として，稀釈液の改善が必要なことを論じた.
6. 差し当たりブドウ糖・クエン酸ソーダ緩衝液の滲透圧を調節して，Δ=-0.90℃ ~ -1. 03℃に引揚げることにより.首曲りを抑止し，その結果，精子は1-2週間にわたり高い受精率を保持することを確認した.
7. 広島方式人工授精は，以上のように改善された3技術から成立する.

In fowl semen, probably avian semen in general, the sperm is not placed in an osmotic equilibrium with the surrounding seminal plasma. Especially the transparent fluid from the lymph folds and vascular bodies exerts hypotonically upon the midpiece of the sperm though it is a regular component of natural semen, resulting in swell-up or disruption of the midpiece. This hydrating action induces further the
sperm to be bent at the damaged midpiece in association with the movement of its tail. It was also found that any medium with the Δ lower than -0.9°C, be it body fluid or physiological saline salution or other artificial dilutors available to mammalian sperms, causes the neck-bending in fowl sperms. Hence, the medium with the optimum concentration for the motility of sperm reversely affects its midpiece, resulting in neck-bending, eventually in low fertility. It seems, therefore, to be justified to conclude that the basic principle for making up the dilutor of fowl semen is to inhibit the outbreak of this defectiveness of the sperm by adjusting the osmotic pressure of its medium by promoting the Δ to - 0.90°C or - 1.03 °C. The experimental data with egg-yolk citrate-glucose buffer osmotically adjusted showed clearly the promotion of biweekly fertility on eggs produced per bird.

This range of ideas appears to be significant in the routine insemination of the fowl.