As one comes in, one goes out
Late Autumn and early Winter are more than a time for changing weather. With our dairy herd, it also means a change in the milking rotation as some girls go dry for their yearly vacation, and others begin to calve in and start their lactations. With Libby drying off just as Big Mama joined the herd, I thought it was a great time to share some of the details (at least how they pertain to our herd, every dairyman runs his farm differently) and explain how we plan to keep milk flowing throughout the coldest parts of the year.
Starting with the basics:
A cow is a mammal and must give birth to produce milk. Similarly to humans, her pregnancy is approximately 9 months long (280-ish days depending on breed). The first milk that comes in is nutrient-rich colostrum, vital for healthy calves. Dairy cows have been bred over time to over-produce, and the vast majority will produce more colostrum than a newborn calf can consume. When that happens we collect and freeze it, usually holding some over for future calves just in case. Occasionally we’ll sell it to our farm customers for their own uses.
A typical cow’s lactation will last for about ten months, beginning with the day she calves and ending on the day she “dries off” in preparation for the next calf. There are many, many variations of this, and no two cows are exactly alike. Some farmers have kept individuals in milk for a year or more, some cows dry themselves up at six months. Our breeding schedule is designed to give our herd a minimum of two months between drying off and their next calving, and in some cases up to three months. This year our cow Liberty needed some extra time to put on winter weight before her due date in March, so she was dried off just this week. Her body was giving us all of the signs that she needed a break and as her caretakers, it was our job to listen.
A cow’s lactation cycle will ebb and flow. Once her colostrum changes over to milk, she will hit peak production between 30 and 90 days in milk. First time moms will be at the later part of this range, and experienced moms will hit their peak sooner. Maintaining production is a matter of nutrition, water, comfort (happy cows actually do produce more milk), and sunlight.
Many of you are probably wondering why it can be difficult to source fresh milk in the winter months, and there are a few reasons for it.
1. The first reason can be farmer preference. Many of us milk twice a day, every day, in rain, snow, sleet, hail, and hurricanes. Milking cows is a very physical, outdoorsy job and a lot of folks take the winter off when they can.
2. Nutrition plays a large role in milk production. Cows are herbivores meaning they rely solely on plants for their nutrition, and in the winter the available plant material will be less nutrient-dense than in the spring and summer. Stored hay also degrades over time, which reduces its nutrient quantity/quality over time. For consumers looking for milk from cows solely fed on grass and hay (no grain), this probably affects you the most. While certain grains can be a controversial topic in the human health world, there is no question that adding grain to a cow’s diet increases her milk production, and not all cows will produce and thrive on a grass only diet.
3. This one you might not have seen coming: daylight. Just like chickens need a certain amount of daylight to produce eggs regularly, cows need 16 hours of daylight to produce the hormones needed to increase milk production (melatonin and IGF-1 specifically). In the winter time the hours of daylight are drastically reduced, which affects the cow’s production of these hormones, which reduces their overall milk output. Here’s a link for anyone curious about natural hormones and milk production, as it relates to the day/night cycle.
As for our herd specifically, we have decided to split it into two groups; our spring calvers and fall calvers. We recently brought home our first Brown Swiss (affectionately called “Big Mama”) who calved in September, and we are looking forward to the addition of another in a few weeks who will have calved in December. These two girls will be partnered up with our Holstein/Jersey cross named Iris, and together they will carry our farm over the winter months while the Shorthorn girls rest. In the spring there will be an overlap, and later next summer when the winter crew is ready for their break, the spring group will carry the farm.
I hope that this helps all who read it to understand some of the intricacies of dairy farming and milk production. If you’re one of our customers you’re probably already aware that I am more than happy to talk your ear off about cows and milk; if you’re not one of our customers then I highly encourage you to ask your farmer what their plan is. Get to know the science and the whys behind their farming methods, because we’re all a little different and that’s a beautiful thing.
