Editor’s note: The following answer is provided by Maurice Eastridge, dairy scientist at The Ohio State University.
Q: What is a good nutritional checklist for improving reproductive efficiency?
A: Almost all dairy farmers would like to improve the reproductive efficiency of their dairy herd, but they must manage many aspects to achieve this goal, including the nutritional program. The feeding program during the dry period, for the fresh cows, and throughout the breeding period is very important for optimizing reproductive efficiency in a herd. Although the voluntary waiting period (VWP) for first insemination following calving is typically 60 days, feeding the herd must be on target before and during this time period.
√ Energy balance: Greatest nutritional impact on reproduction
Energy balance has the greatest effect on reproduction. Intake of cows can begin to drop within one week before calving, and feeding practices today focus on trying to minimize the drop in dry matter (DM) intake before calving to minimize the extent and magnitude of a negative energy balance. Negative energy balance after calving caused by low DM intake and increasing milk yield can be affected by the transition diets fed. Stable DM intake before and high DM intake after calving usually minimize metabolic problems after calving, which, in turn, minimize the impact on energy balance. The goal is for cows to have a body condition score (BCS) of no greater than 3.5 during the dry period and to lose less than 1 BCS during early lactation. Earlier Cornell University data revealed that the first ovulation after calving typically occurs about 10 to 14 days after energy balance is at its most negative point. However, the occurrence of this first ovulation sets in place the timing of the subsequent ovulations, where the third ovulation will likely occur near the VWP.
In addition, it is important to keep in mind that the follicle that will ovulate near the VWP began development about 14 days before calving (the follicle takes about 10 weeks to develop). Thus, the follicles ovulating near the time of breeding were developing during the time of negative energy balance before calving and shortly after calving. The extent and magnitude of the negative energy balance may affect the fertility of the ovum released. So the two keys to achieving good reproductive efficiency are 1) managing the feeding program of transition cows to maintain DM intake before calving and obtain high DM intake after calving and 2) minimizing metabolic problems. To learn more about how pre-calving feeding and management programs impact herd health and future milk production, click here.