The 2011 tax season just finished. Many producers may have considered the amount of money they have spent on feed. This can be purchased or home-grown feeds. Okay, this year might be less than other years due to the great winter, but annual feed cost is normally the largest portion (60 to 75%) of the cow’s cost. You might be asking what this has to do with calving season.
The highest nutrient demands for a cow is early lactation. These nutritional demands need to be met through harvested feed or standing forage. The next year’s calf crop will be influenced by the condition of the cows at the start of the breeding season. However, if cows are in excellent body condition and can lose some condition meeting their nutrients, needs are less critical. Some producers have changed their calving season to eliminate or reduce the need for harvested feeds. Other producers are meeting the cow’s nutrient demands through harvested feeds. I can’t tell you who is making the most money or who is doing it “right”.
In South Dakota, you can find calving seasons from January to June and again in the fall. So what calving season fit your resources?
The answer depends on each operation’s goals, resources and management strategies. There are more factors what play into calving season than just grass/forage production. Let’s say that your primary consideration is to cut costs by matching calving season with forage production. Ideally, the peak forage production and quality would match the cow’s peak nutritional demands. Would you start calving cows, first of March, April, May or June? This answer would depend on your forage source; do you have a stand of native range or a monoculture of smooth brome.
Forage production varies by grass species, temperatures, and moisture, so every year is different. I have seen years with good grass by the middle of May or as late as the middle of June, but have also seen that July 1st is the last of the green grass during drought years. It is difficult to perfectly match the animal’s nutrient requirements with forage production and nutrient content. A producer that is focused on forage based system and trying to limit the amount of harvested feed, matching calving season to forage production/nutrient content is more important. These producers are probably shooting for a later calving season. However, there are other considerations such as labor/field work, grazing permits, land resources, and marketing.