The Effect of Locality and Season on the Composition of South African Whole Milk

The aim of this study was to determine the effect of locality (region) and season on the nutrient composition of South African whole milk as consumed. Whole milk was collected in main cities identified within five climatic regions in South Africa in summer (January and February) and in winter (June, July and August) over a period of 24 months (N=200) and analysed for nutrient composition. The nutrient composition of whole milk in South Africa differed between the five localities and between winter and summer. Most of the variation could be related to the differing composition of the feed and practices (implying the level of feeding and the quality of the cow's diet). These results were confirmed by the analyses of variance results for whole milk, which showed highly significant differences for 44 of the 52 nutrients analysed between localities. CVA showed that locality was responsible for 72% of the variation in the data. When the effect of season was investigated, the analyses of variance results for whole milk showed highly significant differences for 36 of the 52 nutrients analysed between seasons. In the CVA with the season by locality interaction, a clear separation between the nutrient composition of summer and winter milk was observed.