The Lactation Curve

It seems like every year at some point I feel the need to explain the Dairy Cow's lactation curve and how that impacts what we do. Some of you may understand it completely. If that's you I apologize for repeating myself. To many women who have breastfed their own babies, it makes perfect sense. So let's dig in. The graph that I included is key. This graph shows the "volume of milk produced" curve for one cow. Soon after calving milk production peaks. The actual quantified amount of this peak will depend on many factors like breed, feed, genetics, etc. In our system of small jerseys that are not pushed for production with lots of grain, that peak number is probably around 5 gallons per day. Over the course of 10 months, notice that that peak gets cut by more than half. In our case, that means cows that are in the last phase of their lactation are only producing around 2 gallons per day. However, it is also important to notice that the curve ends at 42 weeks (about 10 months). Cows have the natural ability to have 1 calf every year. The reason the chart ends at 10 months is that we give the cow a dry period of 2 months before she has her next calf. During this dry period, the cow doesn't milk at all. She is fed well and allowed to let her body rest and prepare for the next lactation. Now that you have a good understanding of the lactation curve, let me explain our problematic situation this time of year. If you took all of our cows and spread out their calving dates throughout the calendar so that we had the same number of calves each month, production would be relatively flat. Looking at the chart of one cow above, imagine that there was a new graph that started every week or so. In that case, the peaks would be staggered throughout the year, and the aggregate production would be steady. I'll admit, that sounds like a perfect world. The reality however is that a big percentage of our cows have become synchronized. This means that all of their individual lactation curves line up together on the graph. This causes us to have ample milk production when they all have babies but also causes us to have a shortage when they are in the late phase of lactation and in the dry period. Right now, as most of you know, we are in the time of year when that group of synchronized cows is in their dry period. Our dry cow pasture is full of expecting mommas. Our milking herd is as small as it ever is right now. The bad news is that we currently have a very limited milk supply. We are still milking all of the cows that are not synchronized, and we have even had a few babies (very recently). I know we haven't been able to get everyone the amount of milk they wanted, and for that we are sorry. However, there is good news. Soon it will feel like a maternity ward around the dairy. Babies will start dropping soon, and those mamma cows will then take their place back in the milking herd. Milk will be flowing and everyone can rejoice. Until that time, we appreciate everyones patience and understanding. This is a cyclical business, and we will not do unscrupulous things to try to artificially control what is a natural process.