‘Tried and True’ won’t cut it when it comes to stocking numbers

In recent months I have repeatedly stated that beef producers should take a hard look at downsizing herd numbers. In light of high fertilizer, feed and fuel prices, many producers are choosing not to fertilize introduced pastures this year; and understandably so. However, choosing to keep the same numbers of cattle without a fertility program is likely an unrealistic goal that will lead to overgrazed pastures this summer, increased feed and hay dependency this fall and winter, and thinner cows with lowered reproductive performance next spring. It is a vicious cycle, but the problem did not just arise in the last year or two.
Many stocking rates today are considered “static.” If Dad or Granddad stocked at 10 acres per cow, it is assumed that the pasture site is still capable of supporting the same stocking rate of 10 acres per cow today. I would contend that this assumption is erroneous, often times, for multiple reasons:
n The average mature size of our cow herd is larger today than it was 30 years ago. With the introduction of the “Continental” or “European” breeds of the latter 20th Century, cow size increased in proportion to the choice of which breed and/or breeds were used in mating programs.
n Additionally, personal selection for increased frame size and increased milking ability, even within our “British” breeds has also led to heavier mature cows. Purebred Angus, Hereford and Shorthorn cattle, whether registered or commercial, are larger today than they were a mere 30 years ago.
The selection of “Big Northern” as Grand Champion Angus Bull at the 1969 Chicago International Livestock Exposition set the industry on a path toward larger framed, more efficient cattle. However, as is often the case in human history, in many instances we may have erred in our single-trait selection and swung the pendulum too far in terms of mature frame size and mature weights.
n Lastly, many pastures and range sites are not as productive today as they were 40 years ago and are not capable of forage production estimates that served as the basis for those “traditional” stocking rates of your Dad and your Granddad.
A soil’s inherent fertility does not remain constant over time and even if a site has had a history of fertility, the fertility program may not have matched the specific needs of that site. With regards to native range, very few sites are as productive today as they were historically, due to years of overstocking, inadequate rest periods, and a decline in the plant community makeup toward low seral stage grasses, brush and forbs.
Further justification of my position on cow size today is offered by Dr. Glen Selk, OSU Extension Cattle Reproduction Specialist, in a recent edition of the COW/CALF CORNER, a weekly newsletter from the Oklahoma Cooperative Extension Service.
In the newsletter, Dr. Selk says; “Mature weight and milk production of many commercial beef cows are both greater than they were 30 to 40 years ago. Many ranchers have not recently weighed the adult cows in their herd to know what average mature weight to expect. Therefore, most commercial ranchers would underestimate the mature size of the cows.
To expect large, heavy-milking cows to be in moderate body condition at calving and maintain condition through breeding, they must receive more feed than smaller, lighter-milking cows. National Research Council guidelines published in 1996 show the energy needs of a 1,250-pound heavy-milking cow to be about 34% greater than the energy needs of an 1,100-pound moderate-milking cow. Consequently, an operation that was carrying 100 of the smaller cows must carry only 66 of the larger, heavier-milking cows in order to utilize the same quantity of forage produced from that farm or ranch. The same cow will require 34  percent more winter hay and supplement to maintain an equal body condition.
Because we have very high feed, fertilizer and fuel costs, this is a time to reconsider her size to better fit the stocking rate that is adequate for a particular farm or ranch. Reduced stocking rates will be necessary on introduced pastures if lower amounts of fertilizer are applied.
A larger cow size also impacts the principle of percent expected mature body weight for heifers to reach puberty. Many beef producers underestimate the target weight for replacement heifers. If the cow is expected to weigh 1,100 pounds at maturity, the target for breeding her for her first conception is 650 pounds; if she is expected to weight 1,250 pounds at maturity, then she needs to weigh 812 pounds going into her first breeding season to expect a high rate of conception.”
“We let a river shower its banks with a spirit that invades the people living there, and we protect that river, knowing that without its blessings the people have no source of soul.” 
–– Thomas Moore