Evaluation of Milk Enzymes and Electrolytes, Plasma Metabolites, and Oxidative Status in Twin Cows Milked in an Automatic Milking System or Twice Daily in a Conventional Milking Parlor

Daily milk production in the conventional milking system (CM) and in the automatic milking (AM) system throughout the experimental period of 39 wk. Data represent least squares means±SEM. The asterisks indicate that means within week of lactation differed for P<0.05.

Differences between milking frequency in the automatic milking (AM) system and the conventional milking (CM) system in each period before milk sampling. Data represent least squares means (pooled SEM=0.161). The asterisks indicate that mean within period differed from 0 for P<0.05 (*) and P<0.01 (**).

Body condition score in the conventional milking system (CM) and in the automatic milking (AM) system throughout the experimental period of 39 wk. Data represent least squares means±SEM.

Plasma concentrations of glucose and urea in the conventional milking system (CM) and in the automatic milking (AM) system throughout the first 14 wk of lactation. Data represent least squares means±SEM. The asterisks indicate that means within period differed for P<0.05.

Plasma NEFA/total cholesterol ratio in the conventional milking system (CM) and in the automatic milking (AM) system throughout the first 14 wk of lactation. Data represent least squares means±SEM. The asterisks indicate that means within period differed for P<0.05.

Plasma concentrations of reactive oxygen metabolites and thiols in the conventional milking system (CM) and in the automatic milking (AM) system throughout the first 14 wk of lactation. Data represent least squares means±SEM.

Milk pH, and Na and Cl concentrations in milk from cows in the conventional milking system (CM) and in the automatic milking (AM) system throughout the 39 wk of the trial. Data represent least squares means±SEM. When means within week of lactation were different, or a trend was evident, the P-value was reported above them.

Plasminogen, plasmin, and plasminogen/plasmin ratio in milk from cows in the conventional milking system (CM) and in the automatic milking (AM) system throughout the 39 wk of the trial. Data represent least squares means±SEM. When means within week of lactation were different, or a trend was evident, the P-value was reported above them.