690. An investigation of fourteen herds producing substandard milks in the East of Scotland

Abstract

1. Four hundred and sixteen individual cow samples of milk from fourteen herds were analysed for fat, total solids, crude protein, lactose and chloride.2. Wherever possible information concerning feeding, incidence of mastitis, age of cow, stage of lactation and successful service dates was collected.3. The milk samples were divided into normal (with 8·50% S.N.F. or over) and substandard (with less than 8·50% S.N.F.) groups.4. The difference in S.N.F. content between the normal and substandard groups was due almost equally to a drop in lactose and protein, but with the latter playing the major part. Thus, although inadequate feeding was probably a major factor in lowering the S.N.F. in this population the fact that the lactose content was so often low was taken as indicating that mastitis was also important.5. Breed, age of cow and stage of lactation all affected the incidence of low S.N.F. milks.6. On average the substandard milks showed a reduced fat content as well as a lowered S.N.F. level.