Source: South Dakota State University Extension
Author: Julie Walker, Professor & SDSU Extension Beef Specialist
Additional Author: Warren Rusche
Balancing Rations
Research at Ohio State University reported that pregnant beef cows can be fed as little as 3 pounds of hay plus corn and supplements to meet nutrient requirements. Research at Purdue University has shown that late-gestation cows could successfully be fed diets limiting hay to 0.5 or 1.0 percent of bodyweight (dry matter basis). Rations were balanced to meet nutrient requirements, and performance (weight gain) was equal or greater compared to cows receiving hay at 2% of body weight. In both of these research projects, corn plus a protein supplement were used to balance the ration.
In Table 1, rations were formulated to meet protein requirements and maintain body condition. Ration 1 is a traditional hay-based diet using alfalfa hay (19% CP) and grass hay (7% CP). Ration 2 is a limit-fed diet consisting of corn silage, grass hay, and dried distiller’s grains. Ration 3 is a limit-fed diet using grass hay combined with corn and dried distillers. Mineral content was not considered for the purposes of this illustration.
These examples illustrate that diets based on corn or corn-derived feeds are more cost-effective in comparison to diets based completely on hay. Based on the prices used, incorporation of corn reduced the feed cost per day and would stretch the forage supply. It is very important to note that, although the nutritional requirements of these cows are met, appetite is not.
| Feedstuff | ||||
|---|---|---|---|---|
| Corn grain | ||||
| Alfalfa Hay | ||||
| Grass Hay | ||||
| Corn Silage | ||||
| Corn Stalk | ||||
| Dried Distillers Grain | ||||
| Feed cost per day |
*Late gestation diets for a 1400-pound cow maintaining body condition, pounds per-head per-day (as fed basis).
Management Considerations
Of course, every situation is different, and hay costs in some markets may not be as high as the values used in our example. These examples are for late gestation; however, rations can be formulated for early lactation.
Implementing some of these strategies requires limiting feed intake to match cattle nutrient requirements. However, limit feeding creates some alternative management considerations.
- Diets should be based on actual nutrient analyses. Conducting feed tests on forages and other feeds allows purchasing of the right supplements to meet the animal’s requirements.
- The body weight of the cows also needs to be determined accurately. Feeding 1,500-pound cows a ration developed for cows weighing 1,300 or 1,400 pounds could result in nutritional deficiencies, which might impact this year’s or next year’s calf crop.
- Gradually adapt cattle to diet changes, especially if high-starch diets are used (for example, greater than 70% corn inclusion).
- Proper bunk management is extremely important to avoid digestive upsets, as well as some way to accurately weigh and/or mix limit-fed diets.
- Allow plenty of room at the bunk and in the lot (at least 30 inches of bunk space and 500 square-feet per cow).
- Limit-fed rations will meet the cows’ nutrient needs but won’t satisfy their appetite. Strong fences are essential. Providing access to low-quality (cheap) roughage, such as baled or grazed corn stalks, may help satisfy their appetite and provide additional fill. However, this increases the feed costs.
- Just like under more traditional management systems, body condition needs to be monitored to make sure that the cattle are on track to meet production goals.
The Bottom Line
At current feed prices, substituting corn for forage is a viable option to feed beef cows. For operations with the right facilities and management ability, replacing forage with corn can stretch forage supplies and potentially reduce feed costs.
