If a longer lactation length (for example, 305 days) was used, the only difference, if any, could be slight changes in the recommended timeframes from which one should take TD samples.
In contrast, the plasma concentration of the vast majority of the identified phospholipids (five lyso-phosphatidylcholines, four phosphathidylcholines and two sphingomyelins) increased steadily with progression of early lactation post partum (see for example Fig. 12).
In dairy cattle, lactation yields and milk composition (for example protein percentage and fat percentage) are routinely recorded, and these vary greatly between individuals.
It is generally assumed a single measurement of POPs in the body reflects lifetime exposure, although there is variation in the elimination rate between individuals, caused by, for example, age, lactation, and changes in body weight.
For example, from a lactation of 280 DIM, if each combination of five (m = 5) randomly selected TD was tested, there would be over 1.6 × 10 possible combinations.
However, pathological HPRL has to be defined as sustained circulating PRL levels above normal range in conditions other than, for example, pregnancy and lactation, when physiological HPRL occurs [ 8].
Her research is far from armchair: she interviews, for example, a seal-lactation expert in Antarctica, a biologist who studies frozen "infant feces" at Boston College and an Australian dairy scientist who applied techniques from mining technology to measure human milk production.
For example, selection for better lactation ability and persistence, primarily over the past 5,000 years, has increased milk production [ 1, 7].
It has been suggested that persistency measures that are uncorrelated with total milk yield, for example using the shape of lactation curve independent of level of production, allows simultaneous selection for total lactation yield and persistency [ 4, 42].
The individual dairy cows' retention pay-off values differ depending on, for example, their parity, stage of lactation and milk yield [ 3].
