by Sydney Vanderhoff, South Dakota State University

Backgrounding systems are known to have a large effect on animal performance and carcass characteristics. In Midwest production systems, it is common to fall-wean calves and background them during the winter before allowing them to either graze in the summer or be placed on finishing diets. The purpose of backgrounding is to increase the body weight of calves after weaning and before the finishing phase.

Following winter, LOW-rate-of-gain steers had greater ADG than HIGH, which could be a result of compensatory gain.

No matter the backgrounding system used, rate of gain can be improved by increasing the amount of energy and protein available beyond the animal’s maintenance requirements. Distillers’ grains are a common supplement used in backgrounding systems because of their high energy and high protein content. Corn residue is an abundant forage resource and, with the addition of supplementation, can be used to background growing calves during the winter.

A key definition to understand is compensatory gain, which many of us have heard of, but may not know what exactly it is. Compensatory gain is described as, “Cattle on a low plane of nutrition will compensate (make up) when being fed a higher plane of nutrition.” While compensatory gain is complex, and not completely understood, this study is a good illustration of a compensatory gain response.

Investigating backgrounding systems

A two-year study at the University of Nebraska–Lincoln evaluated the effects of backgrounding systems on growing calf performance. We wanted to determine if compensatory gain can be partially explained by differences in intake and if smaller cattle of a similar age eat more as a percentage of their body weight. During the winter period, two different backgrounding systems were used — either drylot or grazing corn residue. They were fed to target 1 pound (lb.) of average daily gain (ADG) (LOW) or 2 lb. of ADG (HIGH). Steers grazing corn residue received supplementation of 6 lb. dry matter (DM) (HIGH) or 2 lb. DM (LOW) of distillers’ grains per head daily. Following the winter period, steers entered the feedlot for a mimicked grazing period to measure intake and cattle gain. The diet consisted of corn silage, wheat straw, grass hay and a supplement with urea. This diet was formulated to mimic grazing cattle with a similar total digestible nutrients (TDN, or energy) to grass pasture.

Results from the winter period and summer period have some key takeaways for producers. At the end of the winter period, calves backgrounded at a high rate of gain (2 lb. ADG) had greater ADG and ending body weight, which was by design to produce a potential compensatory gain response in the following phases. Entering the summer phase, HIGH steers had a greater body weight than LOW; however, LOW steers gained 0.20 lb. per day more during the summer (see Table 1). The difference in ADG in the summer represents a compensatory gain response. Calves backgrounded at a LOW rate-of-gain during the winter period compensated during the summer. With the additional body weight from the winter phase, HIGH steers resulted in a greater ending body weight compared to LOW.

A big factor we looked at during the summer phase was DM intake. DM intake was not different between LOW and HIGH steers. However, intake expressed as a percent of body weight was greater for LOW than HIGH, 2.4% compared to 2.1%.

Key takeaways

Some key points to take away from this data are that wintering at a HIGH rate of gain gives greater gains and ending body weights than LOW rate of gain. Following winter, LOW-rate-of-gain steers had greater ADG than HIGH, which could be a result of compensatory gain. Cattle backgrounded at a LOW rate of winter gain had a greater intake as a percent of body weight, indicating that smaller cattle of a similar age do, in fact, eat to body weight. Reducing performance during the wintering phase results in compensatory gain, but still results in fewer pounds during the entire system. Stocking rate for smaller and larger cattle should be the same, as each group consumed the same amount of DM.

Editor’s note: Sydney Vanderhoff is an extension beef nutrition field specialist for South Dakota State University.