鶏の消化に関する基礎的研究 : VI 嗉嚢摘出が消化に及ぼす影響

嗉嚢が鶏の消化に果す役割を知るために，正常対照鶏と嗉嚢摘出手術後の嗉嚢摘出鶏について，粉餌および粒粉混合餌を給与した際の消化率を比較して，嗉嚢摘出が消化におよぼす影響を検討した.

嗉嚢の有無に関係なく，各成分とも粒粉混合餌の消化率は粉餌のものより有意に低い.嗉嚢摘出による消化率の低下は，粉餌については粗繊維を除く他は僅かであったが，粒粉混合餌についてはいずれの成分においても著しかった.

嗉嚢摘出鶏に粒粉混合餌を給与する際に砂礫を同時に給与すると，いずれの成分の消化率も著しく向上して粉餌給与の際の消化率に近くなった.

以上の結果から嗉嚢が消化に果す主な役割は機械的なものに関わりのあることが確かめられた.

The effects of cropectomy on the digestibility of feed have been studied in ten hens with artificial anus. Four digestion tests each of 5 days were carried out in the following order:
1. With control birds
a) fed with all-mash diet,
b) fed with mash-grain diet.
(after the test (1, h) all the birds were cropectomized.)
2. With cropectomized birds
a) fed with all-mash diet,
b) fed with mash-grain diet.
(half of the birds (2, b) were fed with grits.)

Independently to the presence of crop, the digestibility of mash-grain diet was less than the one of all-mash diet. In the case of cropectomized birds, although the digestibility of all-mash diet was only slightly lower than in the case of control birds, yet under mash-grain diet that digestibility lowered considerably. On the other hand a mash-grain diet fed together with grits improved largely the digestibility in the case of cropectomized birds and grew almost equal to that of all-mash diet.

These results indicate how closely the main function of the crop, in digestion, is related to the mechanical work.