11 June 2012

4 minute read

Beef on grass sounds so simple: Open the gates and let the cattle graze. However, the questions outpace the answers. What is the optimal gain for cattle on grass? What is the optimal gain for steers on grass?

The nutritional needs of the cattle must be met by the grass that is in front of them. The grass will sustain the cattle. However, the grass must not only sustain the cattle, in particular the cow, but also add weight to the steers or market cattle.

Cattle gain is the same as money. Growing grass is good and harvesting the grass through the cattle is great, but the end product must increase in value every day to make the process worthwhile.

So how does one set goals? Some thoughts at various meetings bring some interesting concepts to the table. For instance, if one wants to market 1,300-pound live-grass steers by 2 years of age, the steers will need to gain 1.7 pounds per day to meet the challenge. In fact, at 1.7 pounds per day, the steers easily should weigh more than 1,300 pounds.

Figure that 365 days per year for two years equals 730 days gain. At 1.7 pounds per day for 730 days - equals 1,241 pounds of gain. Add in the typical birth weight of 86 pounds and you get the 1,300-pound or more steer at 2 years of age.

Will the cattle gain that weight? It is well understood that cows and calves gain well on grass. The cows will lose some weight as they nurse their calves, but the calves will gain weight throughout the summer by nursing momma and eating grass.

Typically, for those producers enrolled in the North Dakota Beef Cattle Improvement Association’s CHAPS program, young nursing calves gain approximately 2.5 pounds per day on pasture. However, once those calves are weaned, the questions have fewer answers.

The Dickinson Research Extension Center summered yearling steers last year. Those steers gained more than 2 pounds of body weight per day on summer grass. So, the limited work at the center would suggest that grass will support 2 pounds of average daily gain, even for yearling steers.

Although the center has not evaluated growth through all the grazing months, given the starting and ending weights, the average daily gain of 2-plus pounds from May through a good part of October seems very plausible. That would account for two six-month periods that the steers can gain 2 pounds a day, or 730 pounds total. Adding in the typical 86-pound birth weight, the center should be able to produce 816 pounds of saleable beef coming directly off grass.

Last fall, a sample set of steers came off grass at just more than 1,100 pounds in mid-October. So from weaning to grass turnout the following spring, these steers only gained slightly less than 300 pounds for the six winter/spring months. That is less than 1.7 pounds per day. If one wants to be more critical and assume that 2.25 pounds of gain can be obtained during two growing seasons, then 820-plus pounds should be gained. If you add in the 86 pounds of birth weight, then 900 pounds of saleable beef should have been produced.

That only leaves 200 pounds of gain that need to be produced during the winter/spring months, or just more than a pound per day of average daily gain. That is not acceptable.

So everyone around the table gets kind of fidgety and even questions how in the world a grass system can work during the nongrowing season. The growing season is good, but providing enough forage during the nongrowing season is a real challenge. Extending the grazing season so that those winter/spring fall gains can be met in a pasture system is even more of a challenge, so some leave the room.

However, challenges are good and some goals have been framed. To start with, at least a minimum average daily gain of 2 pounds per day should be expected and certainly achieved during the normal growing season for calves and yearlings. In reality, 2.25 to 2.5 pounds per day during the entire forage-growing season may be a reachable goal.

It only seems right to expect calves following weaning to be able to maintain summer performance. In which case, the same goal could be set, which is 2 pounds of average daily gain through the nongrowing months. If that can be achieved, then during the course of 18 months (initial six-month growing season, six months of winter/spring nongrowing season and then a second six-month growing season), a producer could have a goal to market 1,200 pounds of saleable beef off grass and harvested forage.

Well, 1,200 pounds is not 1,300 pounds. Reaching 2 pounds per day of gain on forage during the nongrowing season has not been achieved at the center. However, we are up to the challenge.