This is regarded as the prolongation of the effects of differential feeding after this itself has ceased. Compensatory effect Supernormal performance on re-alimentation following a period of underfeeding, as with growing stock, is included in this category. Buffering effect This is regarded as the cow's ability to counter nutritional insults by withdrawal of body reserves to support milk production. Total effect This is the summated effect over the total period of application of differential feeding. The main emphasis in this review will be placed on cumulative and residual effects of plane of nutrition within a single lactation together with effects over multiple lactations. These discussions are preceded by notes on the lactation curve, relevant aspects of experimentation, and immediate effects on performance of plane of nutrition.