Matching cattle type and feedlot performance

Cattle exhibit a predictable pattern of feed intake that closely relates to their starting weight. Overall, feed intake increases rapidly for all groups of cattle as they adapt to the feed. Intake then increases slowly or remains the same as weights increase until the end of the feeding period, when intake declines.

A similar pattern occurs across all cattle, regardless of starting weight. But intakes are higher at all points for heavier cattle when placed on feed. This suggests that predicting average daily gain (ADG) from estimated feed intakes that don’t consider start weight may overestimate the performance of heavy cattle.

Calf and yearling feed intake differ across the same number of days on feed. The difference in weight between calves and yearlings doesn’t fully explain the differences in feed intake.  

• Yearling cattle feed intake steadily increases for the first 40 to 50 days on feed, plateaus for 40 days, and then declines until slaughter.
• Calf feed intake gradually increases for about 70 days, then plateaus.

The general shape of the growth curve doesn’t differ between frame size, age, and weight. But cattle with the same age and weight will be at different points on the curve if they differ in frame size.

Separate from breed effects, increasing frame size results in:

• Increased growth rate.
• Increased time required to reach choice quality.
• Decreased fat thickness and marbling at equal weight.
• Increased weight at equal fat thickness.

Large-framed cattle have more efficient gains because they are less mature than small-framed cattle at equal weight or age. Large-framed cattle gain more muscle and less fat than small-framed cattle. But when fed to equal carcass makeup, large- and small-framed cattle are usually equally efficient.

The following table shows how frame size affects growth rate and profit. The rate of gain increases with frame size, but profit shows little change after yearling height reaches 47 inches. In this study, cattle with the most profit were those that grew quickly and reached choice quality grade.

Selection

Feeders should strive to get cattle from herds selected for performance. Frame size can help predict the weight at which cattle will grade choice, but it is only a minor predictor of performance.

Michigan State University fed two groups of cattle with similar frame scores. One group was an unselected line, and the other was a line selected heavily for growth but not for frame size. Over a 221-day feeding period, the selected cattle out-gained the unselected cattle 3.1 to 2.4 pounds per day. Selected cattle produced 155 more pounds of gain per head with similar frame sizes.

Dietary energy

In a 1977 study, small- and large-framed cattle were fed low-, medium-, and high-energy diets during feeding periods of varying lengths. Low-energy diets aren’t practical for an entire feeding period.

Increasing dietary energy had the following effects:

• Increased ADG in both cattle types.

• Improved feed conversion in both cattle types.

• Increased all measures of fatness in small-framed but not large-framed cattle.

• Promoted weight gain in both cattle types.

  • Small-framed cattle gained weight in fat.

  • Large-framed cattle gained weight in muscle

In this study, small-framed and large-framed cattle were slaughtered at an average yield grade of 4.2 and 3.0, respectively. The authors estimated that the dietary energy needed to deposit a pound of lean was the same across diet treatments and frame sizes.

Lightly muscled carcasses may result in deep discounts. Strive to produce carcasses with 2 square inches of ribeye area per 100 pounds of carcass weight. Carcasses with less than 1.6 square inches will receive severe penalties. Even carcasses less than 1.8 square inches may receive discounts.

Crossbreeding systems and within-breed bull and female selection resulted in an industry average of 1.8 square inches.

Performance and cutout

Colorado State University studied differences in performance and cutout between cattle with different levels of muscling. They fed feeder calves to slaughter. These calves included each of the feeder calf muscle scores (1 to 3; 1 is most muscled) and frame sizes (small, medium and large).

Frame size had expected effects on performance and slaughter weight. But muscling didn’t affect feedlot growth rate, even though muscled calves were much heavier entering the feedlot.

Change in live weight poorly describes the performance of cattle that differ in muscling. In this study, muscled cattle had higher dressing percentages and greater muscle yield, despite no difference in growth rate or live weight. The rate of muscle weight gain was greater in muscular cattle.

If carcass or live cattle pricing is based on the muscle or lean content of the carcass rather than weight, muscled cattle will have an advantage. Widespread use of hot fat trimming would enhance the value of muscular carcasses.

Weight

A study comparing cattle of 25 different beef and dairy breeds found that weight accounts for 88 percent of the differences in feed intake within a given breed, but only 14 to 33 percent between breeds.

For young, growing cattle, feed intake within a breed wasn’t proportionate to body weight. So cattle groups of the same breed will have similar feed intakes, which you can predict by weight. Cattle of another breed may be quite different, even at the same weight.

These researchers further found that genetically larger breeds ate relatively more feed at young ages. This may partly explain the effect of start weight on feed intake since cattle with higher start weights were likely more of the larger breeds. Breed comparisons of data from University of Minnesota studies saw low, insignificant links between start weight and rate of gain.

Maintenance needs

Cows

The energy required to maintain a cow’s weight differs by up to 30 percent between breeds. This also holds when the cows aren’t growing, are pregnant, or are lactating.

Work in cows shows that maintenance needs (per unit of weight) highly relate to potential milk production, even when cows are dry. This results from vital organs having a larger mass and a higher energy need in high milk breeds.   

Steers

Maintenance needs between breeds likely differ in steers.

Liver size is associated with within-breed performance in growing steers and is likely to differ between breeds. If so, steers of two breeds that consume similar amounts of feed could differ in ADG and F/G due to differences in maintenance requirements.

A 15 percent difference in maintenance needs between two breed types results in about a 9 percent difference in feed needed for the same ADG. Also, differences in gain composition may cause differences in gain efficiency, with no difference in rate of weight gain.

Dairy breed steers are thought to have maintenance requirements about 12 percent higher than those of beef breed steers. Steers from higher-milking beef breeds may have higher maintenance needs as well.

You can manage dairy breed steers to gain as much, or slightly less than beef breed steers. But they will eat about 8 percent more feed, and thus convert feed less efficiently than beef breed steers.

Feedlot cattle consist of four sex groups: bulls, steers, heifers and ovariectomized heifers. You can implant each of these groups with androgenic or estrogenic hormones. Implanted steers and heifers make up most of all feedlot cattle.

At equal carcass quality, heifers weigh 20 percent less than their steer mates. But since heifers mature earlier, they reach a given endpoint sooner than steers. The difference in feedlot ADG is less than 20 percent; most estimates range from 8 to 15 percent. These differences are similar when both groups have implants. Bulls would likely weigh 10 to 15 percent more than implanted steers at similar composition.

Comparing bulls to steers

When bulls were compared to steers slaughtered at the same age as bulls (Steers I) or at the same slaughter weight as the bulls (Steers II), the performance of the bulls was superior to both groups of steers, even though steers had excellent performance.

Daily carcass fat gain of bulls (0.96 pounds) was similar to Steers I (1.04 pounds) and Steers II (1.03 pounds). Thus, carcass leanness of the bulls is from greater lean gain per day rather than less fat gain. Steers have higher quality grades than bulls.

Most of the performance advantages are reduced if bulls are fed until they grade choice. But many reports show that bulls under 16 months old, fed a high-energy diet for at least 150 days, produce highly palatable beef despite low-quality grades.

There are many reasons why few bulls are fed for beef in the United States, but bull beef may have a future.

Cattle feeders can profit from buying thin feeder cattle and taking advantage of compensatory gain. Older studies (Lambert et al., 1983) have shown that buyers don’t favor fat calves at the time of sale.

Most reports show that cattle subject to restricted dietary energy, which may occur in a pasture or backgrounding system, will compensate when fed high-energy diets. Usually, this compensation will include the following for periods of up to 42 days:

• Increased feed intake (5 to 10 percent)

• Increased ADG (10 to 30 percent)

• Improved feed conversion (15 to 40 percent)

Projecting performance differs greatly between cattle with likely compensatory growth and those without. As condition increases, the energy needed for maintenance rises and the energy for gain declines. You can adjust diet energy or project gains of feedlot cattle based on condition at the start of the feeding period.

A 1982 study suggests caution when buying calves for compensatory gain. In this study, cattle fed 50 percent concentrate diets or grazed on irrigated wheat pasture until they reached 550 pounds had normal compensatory responses when placed on full feed. But cattle that received either of these treatments until 800 pounds compensated very little. The cause is unclear, but it may be that as cattle age or gain weight, their ability to compensate declines.

Condition code: 1 = very thin; 9 = very fleshy. (Fox et al., 1998.)

The following weather elements can affect beef cattle performance in the Upper Midwest.

• Cold
• Wind
• Snow
• Rain
• Heat
• Humidity

You can’t predict the weather, but using adjustment factors will help you adjust projections based on observed weather.

Maintenance needs can increase by over 24 percent during cold stress and during environmental adjustment in commercial feedlot cattle. Gains may decline by about 1/2 pound daily, with little change in intake. As a result, the feed needed per unit of gain increases by about 1 unit. If cattle are acclimated, cold weather can increase intake to meet the greater resting metabolism needs.

In a 1980s study of 14,199 cattle, intakes averaged 8% higher in winter months than in summer months in Minnesota. ADFI peaked in late fall, May and June. The lowest intake occurred in late winter, July and August.

Muddy pens also affect performance. Muddy feedlot pens have accounted for 25-37% declines in daily gain and 20-33% declines in efficiency. Rayburn and Fox 1990 developed prediction equations based on 15 years of Holstein steer data in Minnesota, Wisconsin and New York.