The aim of this paper is to define the critical periods within the lifetime of the cow where metabolic load is likely to have an influence on health, welfare and reproductive performance and to devise management strategies which will reduce the metabolic ‘load’ at those critical periods. The paper uses the data from the SAC Acrehead ‘metabolic stress’ study as its base. This systems study examines a low input (LI) and a high output (HO) strategy and their influence on financial performance, nutrient balance and the health and welfare of dairy cows. Milk yields ranged from 53371 (LI spring calving heifers) to 100191 (HO autumn-calving cows). By using weight and condition-score losses, reduced milk yield and metabolic profiles as indices of metabolic stress, two critical points were identified in the systems. These were in LI systems in years of low forage supply and spring-calving cows at grass in spring. The Acrehead study is remarkable in that it shows that cows of relatively high genetic merit have, in the main, a similar incidence of disease and level of immune function in both systems. However the general level of reproductive performance and incidence of lameness, although comparable with other studies, is disappointingly poor and reproductive performance at Acrehead has been declining over time. Thus there is reason for decreasing the degree of load in both systems. Strategies over the lifetime of the cow designed to overcome these problems in critical periods are examined. These periods are identified as rearing, pre-partum, calving and early lactation. Within each of these periods, management options to overcome load, such as feeding, housing and, where applicable, milking, are discussed. From the combination of systems results from Acrehead and reference to the literature it is concluded that, in the past, too much emphasis has been placed on examining the effects of nutrition alone on metabolic load and its implications. On the other hand, too little research has been conducted on the interaction between nutrition and the management of the cow, in terms of housing and grouping, food trough access and building design. It is also important to recognize that each day within the lifetime of the cow is not independent. Thus management during one period could have an influence during a subsequent period, not only on the likelihood of the cow to experience metabolic load but also on her ability to ameliorate its effects on health and reproduction.