Sound sorting concepts of the spring-calving beef cow herd in the fall should improve the efficiency of the feeding program throughout the winter. But, before dividing up the herd, it makes some sense to inventory the cows to be divided. How many cows of each age group do we have? From previous research data, there are three logical groups of cows to be pastured together for feeding efficiency.
Group 1: The two-year old first calf heifers. They have higher nutrient needs than other cows that are not growing. They are too small to compete with larger, older, boss cows for the supplement.
Group 2: The old cows (10 years and older) and the 2nd calf heifers. In addition, this group should include any of the middle aged cows that were thin and needed extra supplement. Cows that were Body Condition Score 4 or less would be considered.
Group 3: The remaining cow herd. This is the group that is mature in size and in adequate condition to enter the winter feeding period as at least Body Condition Score 5.
If only two groups are possible, putting groups 1 and 2 together would be another logical combination. Ranchers, then want to be certain that the feeding program is adequate to have cows in each group calve as Body Condition Score 5 or 6 next spring.
This may imply that higher quality hay or higher energy supplements (fed in larger quantities) will be given to the young/old/thin cows, while the middle aged cows in good body condition will be supplemented with high protein supplements (in smaller quantities) and free choice access to pasture or grass hays. Because the nutrient needs are not the same for all cows in the herd, improvement in feed efficiency can be made by sorting the cows before winter.
Source: Glenn Selk, Oklahoma State University