Pay attention to the quality of byproducts you feed your heifers.
Can a heifer’s rumen handle the low cost byproducts that she’s often stuck with eating? Do those byproducts really pay off in terms of long-term health and productivity?
Heifers frequently get the low-cost end of a dairy’s feeding program, with little or no attention paid to their health or growth rates.
That’s a mistake, according to Robert Corbett, a veterinarian with Dairy Health Consultation in Spring City, Utah. Corbett spoke about byproducts at the Dairy Calf & Heifer Association Conference in Visalia, Calif., in March.
In fact, it’s just as important to feed a balanced ration to the growing heifer as it is to the lactating cow, he says. And improving the conversion of feed to growth will result in lower-cost rations and improved growth rates.
“In the past, it was thought that regardless of feed quality, the heifer would do just fine,” Corbett says. “Even now, poor-quality forages are often sought for heifers because of the lower price, and heifers receive very little concentrate in comparison to forages.”
The goal has traditionally been to raise the heifer for the least amount of cost, not focus on its health or growth rate, he says. The same approach has been taken when purchasing concentrates. Cost per ton has typically taken precedence over the value of the individual nutrient.
But heifers have special needs, and their protein requirements change. If those needs aren’t met, a heifer’s feed efficiency, growth rate and future milk production are reduced. Ration costs are higher because feed conversion to body weight is lower.
“It’s important to provide high-quality protein sources to meet the requirements of the various protein fractions,” Corbett adds.
Heifers require four types of protein: Nonprotein nitrogen; soluble protein; rumen degradable protein (RDG); and rumen undegradable protein (RUP). Each type needs to be formulated into the ration.
Because the young heifer has a poorly developed rumen, it requires butyric acid for rumen development. That’s produced when microbes in the rumen ferment the carbohydrates found there. Those microbes need both energy and a protein source in proper ratio to optimize rumen fermentation.
Younger heifers require RDG to supply the rumen microbes with the necessary protein. Feeding high levels of RUP decreases the efficiency of rumen fermentation, inhibiting rumen development and forage digestion. Feed efficiency and growth rates are reduced, making ration costs higher because feed conversion to body weight is lower.
One typical byproduct, corn distillers’ grains (DDGs), includes a high percentage of RUP. “That’s not good for young heifers,” Corbett says.
DDGs tend to show high variability between loads, and their protein availability is mostly unknown. They’re also high in unsaturated fat, which suppresses rumen fermentation, and have poor amino acid balance.
Feeding heifers a balanced ration that includes quality byproducts results in improved growth rates, Corbett says. He points to these benefits:
- The cost per pound of gain is reduced when feed effi ciency is improved.
- The heifer’s immune system function is improved.
- Cull rates and death loss are reduced.
- Breeding size is reached earlier.
- Heifers will enter the lactating herd earlier and become productive.
- They produce more milk during their first lactation.
Corbett isn’t opposed to feeding byproducts to heifers. “In some areas, byproducts may be available at a price that can allow them to be effectively utilized in a well-balanced ration,” he says.
But he does encourage heifer raisers to look closely at the quality, not just the cost. “The ultimate goal is to produce a healthy, productive heifer that is allowed to grow according to its genetic potential and is not limited in development by poor-quality feed and/or the lack of a balanced ration,” he says.
CHECKLIST FOR FEED BYPRODUCTS
Veterinarian Robert Corbett says feed byproducts for young heifers should:
- be purchased based on type and cost of nutrient, not cost per ton.
- be consistent from one load to another.
- contribute quality nutrients to a well-balanced ration. “The nutrients present in byproducts may not meet requirements for optimum rumen function,” he says.
- be fed in a constant supply, if possible.
- undergo a nutrient analysis from a reputable lab. Don’t assume that library values are accurate.