Final answer:
Milk production in cattle peaks after calving once the placental hormones inhibiting milk synthesis are no longer present, and the daily milk output on a farm is best measured in gallons.
Step-by-step explanation:
The peak milk production in dairy or beef cattle typically occurs after the cow has calved and the inhibition of milk synthesis by estrogen, progesterone, and other placental hormones is lifted with the expulsion of the placenta. Near the fifth week of pregnancy, prolactin levels begin to rise significantly, reaching a plateau in late pregnancy that's sufficient to initiate milk production. However, actual milk production does not commence until after the birth of the calf when the inhibitory effects of the placental hormones are removed. Megan, who runs a small dairy farm, would measure the daily milk output in gallons, which is the most appropriate unit given the volume produced by her 85 cows