Mepron® increased the Performance of Danish Dairy Herds

Many European dairy farmers suffered a lot from the bad milk price situation in the past few years. Fortunately, prices have stabilized over the last two years and farmers look to continue to be profitable. Nonetheless, a more volatile price situation for dairy products is expected for the future. With feed costs representing the largest input in cost of production, it is of high importance to use the available nutrients in the most efficient way.

Methionine is widely accepted as being the first limiting amino acid for milk protein production, and protein synthesis can only proceed to a level dictated by the most-limiting amino acid. Feeding sufficient amounts of methionine is of high importance for a successful lactation period. Avoiding amino acid imbalances improves efficiency and assists in achieving the genetic potential of the dairy cow. Furthermore, methionine plays an important role in the overall metabolism, as it has many more functions than only being used for protein synthesis.

Our Ruminant Technical Service Manager, Katrin Edelmann, optimized the rations of eight Danish dairy farms, with approximately 2,000 Holstein cows in total and a minimum milk yield of 10,000 kg ECM. The rations were balanced for amino acids in AMINOCow® and Mepron® was supplemented for 3 months. The average inclusion rate of Mepron® was 12 g per cow per day and either fed on-top (6 farms) or added in order to reduce the CP level of the ration (2 farms). This daily dosage was found to be sufficient to full fill the requirement for maintenance and milk production. The CP level of rations was around 17%. The last three months before the trial start were considered as a control period, with milk and feeding data obtained monthly. For the results evaluation, the average performance data of three month (without and with Mepron®) was used. For the farms that were feeding a low CP ration (Farm 7 & 8), the performance should have remained at the same level. There was no remarkable change in the production for Farm 7; however, at Farm 8, an increase of 1.4 kg ECM was observed, clearly indicating that an inadequate methionine level had previously been limiting production.

Then the average performance data of three months before the trial start (control) and three months with Mepron® were compared, 90% of all farms increased production. Overall, ECM increased by 0.7 kg per cow and day (Figure 1).

There was a slight decrease in milk fat and milk protein concentration over time, regardless of the treatment. This might be related to seasonal changes of milk solid concentration. Due to increased milk volume, milk fat and milk protein yield remained the same in the trial period.

For the different number of lactation and in all stages of lactation, an increase in ECM yield was observed as well (Figure 2). The milking control data after the end of the trial period showed an average decrease in production of 0.3 kg ECM per cow and day when Mepron® was withdrawn from the ration.

Of course, feed additives, which are added on top of an existing ration, need to pay off. Income over feed costs (IOFC) is a proven classification number to evaluate the profitability of a dairy farm. Based on the milk price in Denmark of 0.34 EUR/kg ECM (March 2017), IOFC increased by 0.13 EUR per cow and day.