The extremely expensive inputs of feed, fertilizer, and fuel costs have caused many cow calf operations to search for methods of becoming more efficient. One place where many smaller herds could gain some long-term efficiency is by moving to a shorter, more confined breeding season. When all the cows are bred at about the same time and are calving together, their nutritional needs are similar. By contrast, herds with long or year-round breeding seasons, have cows in different production stages consuming the same diet. Consequently, part of the cows are being underfed, or part of the cows are being over fed, or both.
In most herds on a year-round calving season, a natural calving concentration already exists. Nutrition is the major factor responsible for cows cycling and conceiving. Since pastures are usually at their peak of quality in spring and early summer, a natural concentration of calving may occur in late winter and spring. Moving to a spring calving season may be the easiest, however, some producers will benefit by converting the year round system to a fall-calving program. No system of getting on a controlled breeding program can completely eliminate the delaying of some cows from their current calving schedule. In many situations, down-sizing the herd to those cows that more closely fit the future calving schedule may be beneficial. If fertilizer applications are reduced due to price, then lighter stocking rates will be necessary.
Following is a system for converting from year round to a 90-day controlled calving season over a period of three years that would result in less cattle culling than trying to convert in one year. The following steps are suggested for getting a controlled breeding system:
- Build a good, strong bull pen or well fenced bull pasture. An electric fence in addition to regular fence may be needed.
- Remove bull from herd. Select removal date to coincide with latest date you want calves born. Look up the appropriate dates in a Gestation Table.
- Sixty days after removing the bulls from the herd (or at a convenient time near this date), pregnancy check all cows and cull all non-pregnant dry breeding-age females which have been running with the bull and all non-pregnant cows with calves five months of age or older.
- Put bulls back with herd the first year so that calving season will be six months long.
- Start breeding replacement heifers 20 to 30 days ahead of the final long-range planned breeding date for your herd.
- The second year, follow the same system as outlined above except start breeding so that calving season will be about 4-1/2 months long.
- The third year follow the same system as outlined above, except start breeding season so that calving season will be 75 to 90 days. Also, cull all open cows this year when pregnancy checking regardless of age of their calves. The breeding season may be reduced even further in the following years.
Maintaining a controlled breeding and calving season can be one of the most important management tools for cow calf producers. A uniform, heavier, and more valuable calf crop is one key reason for keeping the breeding season short. Plus, more efficient cow supplementation and cowherd health programs are a product of a short breeding season.
Source: Glenn Selk, OSU Extension Cattle Reproduction Specialist