How we address the nutritional needs of a cow herd after calving is critically important if we’re going to have a successful start to next year’s calf crop. If we want a cow to stay on a 365 day calving interval then we have 82 days between calving and re-breeding. She needs to recover from calving and start cycling again during that time period while at the same time providing enough milk for her growing calf.
All of those demands impose a significantly higher nutrient requirement on our cows after calving. Depending on her potential for milk production, she could require as much as 40 to 50% greater amounts of energy and protein compared to the two months ahead of calving. Her needs for nutrients such as Vitamin A, calcium and phosphorus are much greater as well.
A major obstacle we face in meeting her needs during early lactation is the biological priority for nutrients. The first priority for any animal is to meet their maintenance needs first. The next priority in the case of 2- and 3-year old cows would be their requirements for growth. Providing milk for her calf is third in line for nutrients. Finally, if her nutrient intake is high enough she’ll reproduce. It’s very important to keep those priorities in mind when we consider that if she doesn’t breed back we’ll have no calf crop to sell the next year.
Another factor that we need to keep in mind is weather conditions. As we move closer to spring cold stress due to the absolute air temperature becomes less of a concern. However, spring moisture can create its own challenges. A haircoat that is completely soaked loses all of its insulation value. Under those conditions the energy requirements would increase by an additional 2 percent for every degree that the wind chill temperatures drop below 59⁰F. Furthermore, as little as 2 inches of mud can increase the maintenance requirements of beef cattle by 10%. This all can explain why spring storms can often have a larger impact on cattle than winter blizzards. Any steps that we take to improve the comfort and environment for our cow herd will be very helpful, especially during extended periods of cold, wet spring weather.
So how do we meet the needs of that cow in the most cost effective manner? The answer depends somewhat on when your calving season begins. If the start of your calving season is timed so that peak grass production coincides when your cows are in early lactation, the forage resources might very well be sufficient to meet her needs without relying very heavily on harvested feedstuffs. That savings in feed is the greatest single advantage for delaying the start of calving to match up with the grass production in your environment.
If your system involves calving earlier in the year, then we need to make sure that our nutritional plan takes the cow’s higher requirements during early lactation into account. Ideally you would have gone through the process of testing your feedstuffs so that you can save the highest quality forages for this time frame and then provide the right supplements if needed.
Source: Warren Rusche