Winter feed impacts summer, feedlot performance
Research shows the effect of winter rate of gain on subsequent grazing gains and feedlot performance is worth considering prior to developing a backgrounding program. Vet science articles suggest that realizing the long-term effects of utilizing a winter feeding program to achieve certain gains can potentially improve management and marketing decisions.
In the Journal of Animal Science Article (JAS) titled “Effects of rate of gain during winter on subsequent grazing and finishing performance,” authors J.M. Lewis, T.J. Klopfenstein and R.A. Stock conducted a two-year study comparing winter rate of gains of .62, .84 and 1.1 pounds per day.
All cattle in the study were implanted at the beginning of the grazing phase and re-implanted 116 days later at the beginning of the finishing phase. Winter grazing diets consisted of crop residue feeds supplemented with protein and alfalfa hay. Summer diets were comprised of smooth bromegrass, switchgrass and big bluestem grasses with free choice salt. Finishing diets contained corn silage and an alfalfa hay mixture at 11.5 percent protein.
“A decrease in pasture gain was observed as level of winter gain increased due to less compensatory growth made by those animals that gained faster during the winter. At the end of the grazing phase, cumulative total gain from winter and pasture was the same for all three levels of winter rate of gain,” states the article.
University of Wyoming Beef Cattle Specialist Steve Paisley comments that the ability to capitalize on compensatory gains can be very beneficial to producers who have access to quality forages and who have managed cattle for proper frame growth over the winter.
“The amount on compensatory gain is somewhat related to how they were managed over the winter months, but there’s the potential for a very efficient gain for the first 60 days or more after turning out on a higher quality grass,” notes Paisley.
The article concludes it wasn’t beneficial to winter cattle on a program where they gained over .62 pounds per day. This was due to the compensatory gains cattle made on pasture the following summer that resulted in all weights being equal when cattle entered the feedlot. Research also found no effects on finishing performance based on winter rates of gain.
According to Paisley a gain between .50 and .60 pounds per day is the minimum producers should aim for when developing winter feeding systems.
“You can restrict calves too much. If they’re managed for too little growth you can have a negative impact and limit their ability to respond upon being introduced to green grass,” he explains.
A second JAS article titled “Influence of wintering weight change on subsequent pasture and feedlot performance by steers,” was written by T.W. White, F.G. Hembry, P.E. Humes and A.M. Saxton and compared winter feeding programs that fed both above and below maintenance requirements and the resulting performance of those steers.
The three-year trial used black baldy steers fed a winter ration designed to cause a loss of .51 pounds per day or .15 pounds per day, or a gain of .35 pounds per day or 1.57 pounds per day.
Cattle managed for a loss is something Paisley strongly advises against, nothing there will be some frame growth regardless of management and when producers manage for too little growth, future response can be compromised.
“At the end of the wintering phase, 10 steers from each treatment were finished on a 20 percent roughage, 80 percent concentrate diet to a live weight of approximately 925 pounds. The remaining 10 steers from each treatment were grazed for 112 days then finished in the same manner,” explain the researchers.
Results found that cattle grazed after the winter months showed gains that were inverse to those recorded during the wintering phase. Steers from the highest winter rate of the gain program recorded the lowest average daily gain during the following grazing phase. However, the lighter cattle only compensated for roughly 20 percent of the difference in body weights at the end of the winter phase. This was the lowest recorded compensatory gain of all studies looked at.
A third JAS article conducted two experiments and is titled “Effect of live weight gain of steers during winter grazing: I. Feedlot performance, carcass characteristics, and body composition of beef steers” was written by M.J. Hersom, G.W. Horn, C.R. Krehbiel and W.A. Phillips. It compared three groups of cattle in each experiment that were implanted and vaccinated. The first group was fed winter wheat that was always over 15 centimeters tall, while the second group was limited to pastures where wheat was under five centimeters in height. The third group was turned out on dormant tallgrass native range and supplemented with 41 percent crude protein cottonseed meal.
In experiment one, steers average daily gains were 2.89, 1.19 and .35 pounds, respectively. In experiment two they gained 2.43 pounds, 1.50 pounds and .33 pounds per day, respectively.
“At the end of winter grazing, four steers were selected randomly from each treatment to measure initial carcass characteristics. All remaining steers were fed a high–concentrate diet to a common backfat end point,” states the article.
In experiment one the initial feedlot weights of the steers with the highest winter rate of gain were 123 pounds more than those fed limited wheat and 205 pounds more than those fed grass. The final body weights showed steers wintered on grass weighed 68 pounds less than those fed limited wheat and 86 pounds less than those fed the free choice wheat winter diet.
The cattle wintered on grass also required 47 more days on feed than those fed limited wheat and 74 more days on feed than those fed high quality wheat. However, they did exhibit equal or higher average daily gain numbers in both experiments while in the feedlot.
When carcass traits were compared, steers fed dormant grass hung heavier carcasses than those fed limited wheat and lighter carcasses than those fed free choice wheat in both experiments. Dormant grass fed steers also exhibited the lowest percentage of kidney, pelvic and heart fat but were comparable in their marbling scores in both experiments.
“Differences in average daily gain during winter grazing and initial body fat content did not affect rate of gain or gain efficiency during finishing. However, maintenance energy requirements during finishing were increased for nutritionally restricted steers that were wintered on dormant native range,” concludes the article.
Paisley recommends calculating the cost per pound of added gain on calves to identify a decision point.
“It’s about looking at the price you could purchase calves for in the fall verses the price you would receive selling them in the spring and the price slide at those two times. This spring the value of added gain was crazy,” comments Paisley.
He also recommends producers keep future marketing goals in mind when feeding cattle over the winter. Marketing calves as feeders as opposed to grass cattle in the spring impacts how they should be managed over winter months.
Heather Hamilton is editor of the Wyoming Livestock Roundup and can be reached at email@example.com.