When cows are fed well, they produce well
The percentage of protein in milk directly relates to the amount of energy a cow receives from her diet. If she consumes adequate amounts of a high-quality, high-energy diet, she will in turn produce milk with a high protein percentage. Conversely, if a cow's diet is not providing enough energy, her milk protein percentage will be low or declining.
Throughout the season, milk protein will rise and fall in tandem with herd dietary changes. Changes in milk protein % will often occur before you see any change in overall production so a drop in protein is a great early-warning system that all is not well. Monitoring these changes using dockets can be difficult, but when graphed over time, changes become more obvious.
Franklin Vets has invested in a system called Infovet
that allows us to download these graphs very easily. They take some skill at reading, but we have found them a fantastic tool to help our clients monitor and troubleshoot nutrition issues on farm. You can also find these graphs through Fencepost.
The Australian InCalf study identified low milk protein as a key difference between farms with good reproductive performance and those with poor performance, reflecting what an important tool it can be on farm.
The protein cures shown below are from two very different farms. A curve like that of Farm A is ideal and reflects the normal shape we would expect to see through a lactation which resembles a "tick". We are looking for a stable curve that holds at a high milk protein % in early lactation, gets on a rising plane through mating and consistently climbs for the rest of lactation.
The second graph from Farm B shows more variation, especially through November and December; reflecting a drop in intakes over the dry spell. This played havoc with the mating on this farm and many others in the district.
With vats starting to fill again, avoid running into problems by keeping an eye on your protein levels and if you are at all concerned or haven't seen your farm's graph, don't hesitate to get in touch.