Replacing hay with corn-based feeds in cow diets
The recent drop in corn prices represents a tremendous change in the feed cost environment for cattle producers.
“Corn and corn-derived feeds such as distiller’s grains and silage are much lower in price compared to recent history. Hay and roughage costs are lower as well, but on a percentage basis the price decline has not been as dramatic as compared to corn prices,” said Warren Rusche, SDSU Extension Cow/Calf Field Specialist.
Taking into account differences in energy concentration, corn becomes a much cheaper source of energy than hay. Rusche explores opportunities producers may have to exploit these differences in feed prices to reduce winter feed expenses.
He points to three different rations for 1,400-pound cows in late gestation that are shown in Table 1.
“Rations were formulated to meet protein requirements and maintain body condition,” he said.
Ration 1: Is a traditional hay based diet using alfalfa hay (19 percent CP) and grass hay (7 percent CP).
Ration 2: Is a limit-fed diet consisting of corn silage, grass hay, and modified distiller’s grains.
Ration 3: Is a limit-fed diet using grass hay combined with corn and modified distillers.
Mineral content was not considered for the purposes of this illustration. The prices are based on published price data from SD feed markets in early October.
Rusche said these examples illustrate that diets based on corn or corn-derived feeds are more cost effective in comparison to diets based completely on hay. “Of course every situation is different and hay costs in some markets may not be as high as the values used here,” he said.
Rusche added that the corn price is for dry corn (15 percent moisture). “In some cases there may be an opportunity to utilize wetter corn for cattle diets, which would avoid drying charges and shrink resulting in reduced costs for corn growers that also feed cattle,” he said.
He said there are also potential advantages in harvesting corn at higher moisture content due to greater flexibility in harvest timing and reduced risk of inclement weather causing harvest delays and losses.
Rusche said that implementing some of these strategies requires limiting feed intake to match cattle nutrient requirements. In order to do that successfully, there are some management factors that need to be considered. Some of these include:
Diets should be based on actual nutrient analyses.
The body weight of the cows also needs to measured or estimated accurately. Feeding 1,500 pound cows a ration developed for cows weighing 1,300 or 1,400 pound could result deficiencies sufficient to affect this year’s or next year’s calf crop.
Gradually adapt cattle to diet changes, especially if high-starch diets are used (e.g., greater than 70 percent 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 ft2 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.
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.