Feedlot Nutrition in Today’s Climate

Tactics For Improving Animal Health and Productivity

By Zachary Smith, Ph.D. Department of Animal Science, South Dakota State University

Three factors that influence the profitability of a cattle feeding enterprise include: an abundant supply of feeder cattle, readily available and economically priced feed, and a favorable production environment. For example, in South Dakota, we are fortunate to be close to an abundance of quality feeder cattle and feedstuffs. However, South Dakota must combat wintertime and summertime weather conditions which challenge even the best cattle feeders. Challenges to cattle and their caretakers in the wintertime include cold temperatures, wind, snow and freezing rain, all of which result in undesirable pen surface and cattle hide conditions. Challenges to cattle and their caretakers in the summertime include warm weather and humid conditions, coupled with very long days with limited opportunity for nighttime cooling.

Mitigation of Environmental Stress in Feedlot Cattle

Bedding application as a means to improve cattle comfort during wintertime has been commonplace for Northern Plains cattle producers for many years. However, the exact degree to which bedding application improves growth performance has not been well established. As such, an experiment was conducted at the Ruminant Nutrition Center in Brookings, South Dakota, from January to July of 2019. The goal of bedding application was to ensure all steers within a bedded pen had a dry spot to lay down at all times during the course of the experiment. Steers that received bedding were provided on average 4 lbs (as-is basis) of wheat straw bedding per day. The average ambient temperature and the average wind chill was 5.2°F and -0.3°F for the first 36 days on feed (January to February) and 39.8°F and 37.3°F for the cumulative feeding period that lasted from January to July.

Steers from the bedded treatment had 4.2% greater body weight on day 36, 48% increased average daily gain, and were 74.4% more efficient in the first 36 days. During the entire finishing period, steers from the bedded treatment had increased average daily gain by 21%, greater dry matter intake by 5.9%, improved feed conversion by 14.6%, and required 35 fewer days on feed to reach an industry acceptable level of rib fat compared to nonbedded steers.

The return on investment (ROI) for bedding after accounting for labor, equipment and material needs ranged from 2:1 to 1:1 depending upon bedding material cost. While the ROI was modest with more expensive bedding, a key point here is that one will likely incur the cost associated with bedding cattle no matter what they choose to do (i.e. the extra 35 days of yardage and feed costs for the non-bedded steers). Another factor to consider is for an integrated crop-livestock business the nutrient value of the crop residue will be returned to cropland as part of the manure, hence, reducing the net cost of the bedding. There are also less tangible, but still important, benefits to bedding that should be considered like enhanced visual appeal of cattle to be sold as backgrounded feeders and improvements in overall cattle comfort and welfare. These data indicate that enhancements of growth performance for bedded steers compared to non-bedded steers were not solely attributable to increased dry matter intake, but rather, reducing the impact of cold-stress on their maintenance energy requirement.

Summer in the Northern Plains is generally quite pleasant. There are times, however, when summer feeding conditions can severely impact cattle growth performance. Typically, the worst summertime feeding conditions occur sometime during June or July. Warmer weather coupled with limited nighttime cooling and humidity create many challenges to cattle feeders. While we cannot control Mother Nature, we can work to ensure cattle comfort and productivity by altering time of feeding, providing access to additional sources of water, and not shipping or handling cattle during extreme heat events.

In the summer of 2022, we had a set of black-hided steers on feed at the Southeast Research Farm located near Beresford, South Dakota. All steers were placed on feed at the same time, were of similar genetic make-up, and had been under our care since early March. These were high-quality steers that had been well backgrounded the previous winter and had tremendous growth potential. For the cumulative feeding period, cattle growth performance was within 1% of expectations based upon intake and diet energy density. From early May to early June, cattle growth performance was 4% better than expectations (range of 13% better to 5% poorer) based upon intake and diet energy density. From early June to early July, cattle growth performance was 33% poorer than expectations (range of 3% to 65% poorer) based upon intake and diet energy density. Upon further investigation, it was revealed the cattle that performed the poorest were in a location in the feedyard with the poorest wind movement across the feedyard (Figure 1; Location 1). These pens were surrounded by the shelterbelt to the west and an old hoop-barn to the south. The cattle that performed the best were on the side of the feedyard with the best opportunity to capture wind movement across the feedyard (Figure 1; Location 6). These data indicate that understanding potential problem areas within the yard can allow for more timely and meaningful heat stress mitigation practices. The shelterbelt provides protection from the north wind during winter months coupled with the old hoop-barn resulted in poor air movement across the pen for cattle fed in Location 1. Pens with greater protection for wintertime feeding can become problem areas during the summer months.

Economic Benefits of Implanting Finishing Steers

Beef cattle producers must choose the best production system for their situation. Conventional production systems use steroidal implants with anabolic activity, ionophores and betaadrenergic agonists to improve animal productivity; feed grade and injectable antimicrobials are also used to control, treat or prevent disease, and improve animal health. For the purpose of this discussion, we will only discuss steroidal implants with anabolic activity. Steroidal implants with anabolic activity have been safely used to enhance food security and environmental sustainability for nearly 66 years. Typically, implants increase average daily gain by 10%-30%, slightly increase intake, and enhance dry-matter feed conversion by 5%20%. Technologies like steroidal implants with anabolic activity, in part, have allowed each cow on the prairie to produce 50% more beef than she did in 1980. Put another way, U.S. beef producers produce as much beef today with a cow herd that has 33% fewer cattle than in 1980. However, some prefer to have beef raised without conventional technologies. Not using these technologies increases the cost of production. These production losses must be off-set by premiums when the cattle are marketed and sold.

Premiums for non-hormone treated cattle (NHTC) can easily reach up to $25/cwt compared to implanted cattle. While this seems like a very nice premium, it is important to remember that a single finishing phase implant can add up to an additional 100 lbs. of carcass weight. If the carcass price for the finished cattle is $250/cwt, and a single implant can increase carcass weight by 100 pounds, we can assume the non-implanted steers would have an 800 lb. carcass and the implanted steer would have a carcass weight of 900 lbs. The cost differential is an extra $250 per steer of additional revenue at the time of selling, when this $250 per steer of additional money is divided by the carcass weight of the steer, the value of the additional weight gain is $27.77/cwt. When the math is presented in this manner, the $25/cwt premium for the non-implanted steer is not nearly as attractive. A disclaimer here, the math is not as simple as shown here due to the fact that additional feed intake by the implanted cattle was not considered, alternatively, increased initial purchase cost for the NHTC feeder calf was also ignored in this example. The purpose of this demonstration is to show that you should always run the numbers and not be lured into a management strategy that appears to generate more income based solely upon a “premium.”

Conducting applied confinement cattle research in the 21st century is exciting. We have much to be proud of in regard to enhancements in productivity in the last 40 years. The challenge moving forward is to keep the momentum. In 1980, I am sure beef producers looked back on the previous 40 years and thought, how will we ever make the same progress since 1940? They stepped up to the plate and made huge progress. It is now time to make the same commitment. Doing so will guarantee beef is at the center of the plate, and beef will remain the undisputed and preferred protein both domestically and internationally.