Lipolysis and the distribution of lipase activity in XXXX milk in relation to stage of lactation and time of milking.

@entity1718 @entity291 @entity41837
The increase in levels of free @entity1718 (FFA) in morning and afternoon milk after 48 h cold storage at 5 degrees C was determined at two stages of lactation in milk from 96 @entity291 . Lipolysis was positively correlated to day of lactation (r = 0.6, P less than 0.001), while the correlations between lipolysis and milk yield and fat content respectively were due to these factors being related to day of lactation. In afternoon milk the level of FFA increased almost three times above that in morning milk. Lipolysis was closely related to the @entity41837 ( @entity41837 ) activity associated with the cream fraction (r = 0.8, P less than 0.001). Afternoon milk had higher @entity41837 activity in the cream fraction than morning milk. Lipase activity in the cream increased with increasing stage of lactation. Cooling of milk increased @entity41837 activity associated with the fat phase. This effect was greater in afternoon milk from late lactation than in morning milk from early lactation. When heparin was added to milk the @entity41837 activity associated with the fat increased substantially; again, this effect was greater in afternoon milk from late lactation than in morning milk from early lactation. Lipolysis was higher in heparinized milk than in normal milk, and there was a close correlation between lipolysis and @entity41837 activity associated with the fat (r = 0.82, P less than 0.001). Characteristics of the milk fat globule influencing the attraction of @entity41837 were found to be fundamentally important to lipolysis.
