Limit Feeding Cows in the Absence of Distillers Grains
October 2012
The drought this year has left many producers with a limited supply of high and medium quality hay. University of Nebraska recommendations have included mixing low quality forages such as ground wheat straw, cornstalks, or Conservation Reserve Program (CRP) hay with corn distillers grains and limit feeding that diet to confined cows.
Limit fed cows are not allowed ad libitum access to feed. Rather, dry matter intake of a high energy diet is limited to less than 2% of body weight while still meeting the nutrient requirements of the cow. This allows producers to reduce the amount of feed required to maintain their cows in adequate body condition. Unfortunately, as a result of the drought, distillers grains are not readily available, especially in the western part of the state.
Due to the drought this year, dryland corn not suitable for a corn crop was chopped for silage. Corn silage can be mixed with medium to low quality forages and limit fed to maintain dry, pregnant beef cows in confinement. Cows that are not lactating and are in the middle third of gestation, have fairly low energy requirements.
The example diet in Table 1 could be limit fed at 1.75% of body weight to 1200 lb cows. The diet contains 8.1% crude protein, 62.5% TDN, 46% dry matter, and supplies 12.7 Mcal/d when 21 lb of DM are fed. This diet was formulated using corn silage containing 72% TDN and 11% CP and poor quality CRP hay (48% TDN and 3.5% CP).
| Table 1. Example Limit-Fed Diet Containing High Quality Corn Silage and Poor Quality Roughage for Confined Cows | ||
|---|---|---|
| Item | DM lb/hd | As is or Actual lb/hd |
| CRP hay or wheat straw | 8.25 | 9.3 |
| Corn silage | 12.75 | 36.4 |
| Total | 21 | 45.7 |
All forages should be sampled and sent to a commercial laboratory for crude protein, dry matter, TDN, and nitrate concentration. Please see the video below for UNL Extension Beef Specialist Rick Rasby's explanation of how to properly take a sample in a bunker.
Knowing the quality of the forage will be critical for balancing the diet to meet the needs of the cow. If the silage available is lower in quality, some supplemental protein or energy may be required.
Table 2 is an example of a diet formulated with drought stressed corn silage containing 64% TDN and 9% CP. This diet contains 8.2% CP, 60% TDN, and 50% DM. It supplies 12.3 Mcal/d when 21 lb of dry matter are fed to 1200 lb cows.
| Table 2. Example Limit-Fed Diet Containing Drought Stressed Corn Silage, Poor Quality Roughage, and Range Cubes for Confined Cows | ||
|---|---|---|
| Item | DM lb/hd | As is or Actual lb/hd |
| CRP hay or wheat straw | 8 | 9 |
| Corn silage | 10.5 | 30 |
| 20% CP Range Cube | 2.5 | 2.8 |
| Total | 21 | 41.8 |
Contact your local extension office for help balancing a limit-fed diet.
When feeding diets that are limit-fed, make sure there is plenty of bunk-space (24 to 36 inches) per cow. In addition, if possible, separate young cows from older cows as it may be difficult for young cows to eat their share of the diet. Young cows are the ones that are likely being pushed away from the bunk by the "boss" cows when the ration is fed once daily.
Karla H. Jenkins
Cow/Calf, Range Management Specialist
Panhandle Research and Extension Center
University of Nebraska–Lincoln