Originally published in Progressive Cattle magazine:

http://www.agproud.com/articles/61010-southeast-managing-the-first-calf-heifer 

First-calf heifers are a group that often presents challenges to cow-calf producers. They are demanding not only due to potential calving difficulties but also because they have the greatest nutrient needs in the herd, and their reproductive performance has long-term effects on herd success. Rebreeding early in the season is essential to ensure their long-term contribution to the herd. This starts with breeding them early as replacement heifers, allowing earlier calving and extra time to return to estrus for the next breeding season. Studies show that breeding failures in two- and three-year-olds can significantly affect overall herd reproductive success, not to mention profitability of the cow-calf enterprise.

The high energy needs of first-calf heifers stem from dietary energy being divided among various requirements. Energy use in the body is prioritized, meaning if basic needs aren’t met, additional performance is impossible. The first priority is maintenance, ensuring the animal’s survival and basic physiological functions. Next, lactation needs are met so the heifer can produce high-quality milk for her calf. Remember, these first-calf heifers are not fully grown yet, either. First-calf heifers are only about 80% of their mature body weight, so growth is another requirement. Under these conditions, establishing a new pregnancy is not a priority for the body, making timely rebreeding difficult, particularly if dietary energy is insufficient.

To manage first-calf heifers effectively post-calving, separate them from the mature cow herd. This allows for tailored nutritional management, ensuring they receive adequate nutrients without underfeeding heifers or overfeeding mature cows. Closely monitor their body condition during the post-calving period, especially if transitioning to pasture. Moving to lush pasture or consuming wet feeds, such as baleage or silage, can limit dry matter intake, potentially causing energy deficiencies. In such cases, additional energy or ration adjustments may be needed. A body condition score of 6 is optimal for successful calving and reproductive performance. Heifers should enter the calving season and maintain body condition about one score higher than mature cows. Finally, provide a high-quality mineral supplement. While energy and protein are like bricks in a wall, minerals and vitamins are the mortar holding it together. A good mineral program supports lactation and breeding efforts for this demanding but highly valuable group of cattle.

An investment in nutritional management is an investment in reproductive success and good investments pay dividends in return. Time and money well spent on the management first-calf heifers can set your cow-calf operation up for long-term success.