To observe the animals 'digestive processes more closely, Chen used a "Rumen Fistulated Cattle Experiment" which involved inserting a plastic "window" in the cow's stomach.
所謂「牛胃開窗」，又稱為「瘤胃管手術」，就是在幾條實驗乳牛的肚子上開個大洞，等傷口癒合後，在洞口加上一面圓型的塑膠「窗子」，牛胃裡飼料消化的情形，可透過「窗子」看得一清二楚。