As consultants, the walk-around is a part of our routine. Among other things, we classically evaluate execution by observing the mixing of a TMR load, but there are details that may escape the eye.
A routine farm visit on a dairy milking 2,200 Jersey/Holstein cross cows in New Mexico revealed one of those hidden opportunities.
This dairy fed a fresh cow ration and a high cow ration during transition as a means to alleviate fresh cow problems.
Cows were moved to a primary fresh pen (pen 1) post-calving for five to seven days for intensive observation. A secondary fresh pen (pen 2) followed where cows were routinely examined, marked as OK to breed and moved to the AI pens at around 35 days in milk. Both pens 1 and 2 were fed the fresh cow ration. Cows were moved weekly to the high cow ration, the number also depending on the room available in the AI pens.
Yet, after observing the staff and reviewing the distribution of cows in pen 2, it became clear that some cows were staying in the secondary fresh pen longer than needed.
It had always been assumed that cows were being moved at approximately 35 DIM, depending on the calving pressure, and that DIM was being used to select such cows. This was clearly not the case and an appreciable number of cows with DIM greater than 35 DIM remained in pen 2 and on the fresh ration.
Understandably, the focus should and does fall on the early transition period. Staff is easily distracted by the early lactation fresh cow problems. We may neglect to pay attention to the other end of the transition cow period and cows on the fresh cow ration, even when the fresh cow problems have been resolved. From experience, it is not uncommon for cows to stay on a fresh cow ration longer than is needed or intended.
The relative differences in the nutrient content of the fresh and high cow rations, as well as number of days on the fresh cow ration and/or calving pressure, will determine the likely impact. It can only be partially captured by such indexes as 1st or 2nd test day milk and/or days to peak milk and/or week 4 milk. (Transition Management Checklist, M. W. Overton, W. Gene Boomer & Patrick J. Gorden).
Unfortunately, these numbers are averages and may not reflect the outliers and lost opportunity. A lactation curve generated with daily milk weights may reflect a plateau, or even decease in milk yield, revealing a double-peak milk lactation curve. Even monthly milk weights may reveal this as an issue when severe enough and when reviewing individual lactation curves.