Year Round Grazing Program: Matching Cow Numbers to Standing Forages

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By Edward A. Hanes of the Department of Agricultural and Applied Economics, Virginia Tech

Commonly asked questions from farmers are how many cattle can I run on my farm in a Year Round Grazing Program (YRGP)? What choice of forages do I have in formulating this program?

To answer these questions you must first set some standards to help deal with the variability in cow sizes, forage yields, and animal performance. Second, you must establish a reasonable estimate of the number of days that the forage will not be available for grazing because of snow cover, ice or severe mud conditions. In Southside Virginia, use 60 days in which hay should be available for feeding. Other areas of the state may require more than a 60-day supply of hay. Do not underestimate your hay needs, but challenge yourself by trying to supply a grazeable crop that is of good quality, especially for the growing calves, every day of the year.

Allow 25 pounds of good quality hay daily for each 1,000-pound cow. If this cow ate only hay for 365 or 366 days she would require 9,150 pounds for the year, or 1,500 pounds for 60 days.

However, if this cow weighed 1400 pounds then you need to allow 1.4 times 9,150 pounds to equal 12,810 pounds of hay equivalent for grazing of which (1.4 X 1,500 = 2,100) 2,100 pounds is needed for the 60-day inclement weather period.

Or if this 1,000 pound-cow is nursing a calf that weighs nearly 600 pounds, she would require (9,150 X 1.6 = 14,640) 14,640 pound of hay equivalent for year-round grazing. Of this amount (1,500 X 1.6 = 2,400), 2,400 pounds of hay is needed to supply the cow and calf during the estimated 60-day hay feeding period.

YRGPs may be very simple, using fescue only, if lower animal performance and lower carrying capacities can be tolerated. The economics of the situation may warrant a more diversified forage program that will give better summer gains and/or higher forage yields such as dwarf pearl millet or small grains, Caucasian bluestem, switchgrass, clovers, orchard grass. (Refer to publication 418-015, 2:1 Year Round Forage System, publication 418-013 Planting and Managing Switchgrass for Forage, Wildlife and Conservation, publication 418-014 Establishing and Managing Caucasian Bluestem).

Next, you need to establish your farm's forage yields under your current management program. Establishing yields can be done by randomly weighing some of your bales and multiplying the weight by the number of bales per acre. Yields should be calculated on a field-by-field basis. However, hay losses must take into account weathering and feed losses. Remember the cow's hay requirement is based on good quality consumed hay. Since in mild winters hay may be carried over for one or more years, an incentive to build hay sheds or to use some type of cover to build inventories for severe winters exists. Ample hay for the most severe conditions is always recommended under any forage program.

Many of you can increase grazing days by using a better soil fertility program, fertilizing in the fall to maintain a thicker, longer-lived stand, stockpiling fescue, adding clovers or species that have higher yields potential, or grazing fescue when it is more digestible and efficient such as in the winter months. Soil maps are beneficial in determining the potential forage yields of each soil on your farm. These maps are available from local soil conservation offices.

If feeding calves creep to obtain the desired weaning or selling weight is necessary, corn, barley, soybean meal, and a vitamin-mineral mix that is 14 to 16 percent crude protein and 64 to 70 percent total digestible nutrients (TDN) is suggested. Broilers litter may be used in the ration if the calves are over 500 pounds.

Cows grazing on winter pasture should always have free choice access to a good quality mineral-vitamin mix to prevent winter tetany or breeding problems.