Hi Akmal. I am a member of the Technical Service Team at Balchem. Your question is a good one. Most of our research has been done with Transition Cows (3 weeks prepartum to 3 weeks postpartum). The benefits of increased milk production (whole lactation) and cow health are consistent and repeatable. We have also seen clear benefits to calf health and growth (out to first calving). We believe the calf growth response is an epigenetic effect of supplying additional methyl-donors during late gestation.
We have conducted a couple studies looking at supplementation beyond the 1st 21 days of lactation. These studies were focused on production. We did not see any advantage to feeding beyond 21 days postpartum. But there are areas that we still need to explore (methionine sparring, methyl-donation and potential epigenetic effects on the developing fetus for example). We are also looking at the potential benefits of extending prepartum feeding to encompass the entire dry period but do not have any data on that at this time.
Given that some methionine is used in the synthesis of choline ensuring adequate supply of the later spares the former for other vital functions including production of milk protein and immune function.