by Adam Hartfiel

For some producers, calving season is just around the corner, while others are preparing for it to begin in a couple of months. Throughout this calving season, remember that continuing proper cow management is necessary for your herd to have a successful, tight calving window next year. One of the most effective ways to manage the postpartum interval is to maintain the body condition scores of your herd.

Beef cattle body condition scoring uses a scale of 1 to 9 to quantify overall body condition, with 1 being an emaciated cow and 9 being an extremely overweight animal. Body condition scores help make management decisions because thin cows with a low BCS of 1 to 3 will experience low production and reproductive performance. Producers should target management of forages, feed and pasture so cows reach a BCS of 5 to 6 at breeding to achieve optimum conception success. Research has demonstrated that cows with a BCS of 4 or lower had pregnancy rates of 61%, in contrast to 90% for cows with a BCS of 5 or greater.

Cows with a BCS of 5 typically have a few ribs visible with little fat in the brisket region. Their hooks and pins are clearly defined with a smooth overall appearance. Overconditioned cows (BCS 8 and greater) also will experience reproduction issues, such as retained placentas, and likely will have a difficult time being rebred due to metabolic issues. Maintaining body condition at 5 to 6 with minimal changes throughout the year is usually the most economical way to manage a cow’s nutritional needs.

First-calf heifer challenges

Younger cows and first-time heifers often have more trouble maintaining their body condition because the nutrients they consume are going into lactation for their newborn as well as their own growth. First-calf heifers continue to grow to their mature size until about 4 years old. Nutrient allocation is prioritized to the young cow’s growth over lactation and reproduction.

First-calf heifers need to return to normal estrus 80 days after calving, but they will not be able to do that without sufficient nutrition. It may be beneficial to ensure first-calf heifers and younger cows are at a BCS of 6 prior to calving to accommodate the greater energy needs they have due to the demands of their own growth. However, feed costs and availability and pasture quality are obstacles producers may run into while trying to increase or maintain the body condition of their herd.

Maintaining body condition is just one piece of the puzzle that could help get cows bred back in an ideal time frame for a tighter calving window. Having a tight calving window is important. Calves born closer together provide a more uniform group at sale time due to being closer in size and age.

Replacement heifer calves born during the first 21 days of the calving season have increased weaning, pre-breeding and pre-calving body weight during their first reproduction period compared to calves born later in the same calving season. Calves born during the first 21 days of the season could mean higher average group weights come sale time, or increased chances of cycling before breeding.

Cows may experience a net-energy-deficient period prior to calving as the enlarged uterus effectively shrinks rumen capacity, unless the ration takes this reduced intake ability into account. The key is to manage this time so cows do not lose body condition. By maintaining good body condition early on, you set up yourself and your herd for better success in the future.

Hartfiel is the regional University of Wisconsin Extension livestock educator for Adams, Green Lake and Waushara counties.