The general characteristics of a group of thirtynine herds of dairy cows in the Eastern Counties of England, and the method of obtaining information about their diet during the winters 1938–9 to 1942–3 inclusive, are briefly described.

The first three winters of the war show a continuous decline in starch equivalent and protein equivalent per cow, followed by a recovery during winter 1942–3.

Comparing winter 1942–3 with winter 1938–9: Consumption per cow of concentrates declined by one-third, reductions in proprietary compounds and mixtures and in maize and wheat products being outstanding.

The more important increases were in oats, straw and succulent foods, notably mangolds, sugar-beet tops and kale.

Hay retained its important place with little overall change; a modest increase in silage was restricted to a few herds.

The crude weight of the average daily ration increased from 44 to 61 lb., but its dry matter only from 21·0 to 22·6 lb.

The residue: total dry matter less digestible organic matter—increased from 7·2 to 8·4 lb. per cow daily. Reference is made to changes in palatability.