The effects of sheep αs1-casein CC, CD and DD genotypes on milk
composition and cheese yield were studied. Processed bulk milk was collected from
three groups of 15 ewes, carrying αs1- casein
CC, CD and DD genotypes. CC milk was
higher in casein content than CD or DD milk (+3·5 and +8·6% respectively), and
had a higher protein[ratio ]fat ratio and a smaller casein micelle diameter. In addition, DD
milk had a significantly lower αs1-casein content.
The main differences were in curd
formation: CC milk had better renneting properties. Cheesemaking trials, carried out
in a pilot plant, showed that CC milk had better cheesemaking characteristics than
DD milk, while CD milk was intermediate. Both 1 d old and fully ripened cheeses had
different fat[ratio ]dry matter ratios and αs1-I-casein
electrophoretic mobilities: these were
lower for DD cheese. As a consequence, these genotypes could be considered as
markers of milk and/or cheese quality.