High frequency of Swedish Landrace goats are the carriers of a mutation, where the affected goats are not able
to produce αS1-casein (αS1-CN) in the milk. As a consequence the lack of this protein is connected to lower cheese yield.
The aim of this study was thus to determine the relationship between the αS1-CN content and coagulation properties of
milk from Swedish Landrace goats. Milk samples from 62 dairy goats from two herds were analysed. As many as 44%
goats showed low or no production of αS1-CN. Only 24% of the investigated goats showed high production of this protein.
The coagulation properties of milk from the dairy goats were clearly influenced by the concentration of αS1-CN. The milk
from low level αS1-CN animals resulted in 15% longer coagulation time and 60% weaker gels compared to the gel
firmness of the high expressing group. The coagulation time was strongly associated with the pH of the milk (p<0.001),
where the milk with low αS1-CN content had higher pH. Further, goat milk with low levels of αS1-CN was shown to have
significantly lower total protein (p<0.05) compared to milk from high expressing αS1-CN goats.