With a dairy as a new neighbor, Chris Urbanczyk had another market for his corn silage. But with rising irrigation costs, he wasn't sure that he could increase his production economically. He hopes brown midrib (BMR) forage sorghum is the answer.
BMR forage sorghum has had some promising showings in key dairy regions. Due to its lower lignin content, it offers better digestibility than other forage sorghums without sacrificing yield. And for irrigators like Urbanczyk, costs for supplemental watering are about 50% lower than with silage corn.
“With BMR sorghum, our production costs declined by $100 or more per acre,” says the Hereford, TX, grower.
That Panhandle community, always a mecca for feedyards, is the site for several current and proposed dairies. However, with an annual rainfall of 18" or less,25" or more of supplemental irrigation are needed to produce a 25- to 30-ton corn silage crop.
“Even though there is a market for corn silage, we needed crops with lower input costs,” says Urbanczyk. ”From what we've seen from Texas A&M forage trials and our own production, BMR sorghum could be the solution.”
Brent Bean, Texas A&M extension agronomist at Amarillo, says 2001 and '02 trials of 77 forage sorghum and sorghum-sudangrass varieties yielded promising results.
“Some have feed value, yield and digestibility numbers that approach those of corn,” says Bean. “Dairies are really interested in the potential for BMR forage sorghum as an alternative to corn silage.”
In Bean's 2002 study, 27 BMR forage sorghums had an average yield of just over 26 tons/acre, about 2.6 tons below the overall study average. Crude protein for most of the BMR lines was just over 7.5%, compared to 7.2% for the entire test. ADF levels were a little over 30%, compared to 34% for the overall test. NDF averaged about 49%, compared to 53% for the overall test. In vitro true digestibility (IVTD) for nearly all of the BMR lines averaged about 80%, compared to 76% for the entire test.
He also tested four corn silage hybrids yielding just over 25 tons. Crude protein was 7.46%; ADF, 26.9%; NDF, 44.8%; and IVTD, 81.2%.
“Some BMRs were comparable to corn,” says Bean. ”And BMR forage sorghums received 14.5" of in-season irrigation compared to 24.6" needed for corn silage.”
Urbanczyk saw 24-ton BMR sorghum yields from hybrids from two seed companies: Richardson Seed, Inc., Vega, TX, and Garrison & Townsend, Hereford, TX. His corn silage yielded about 30 tons.
“We had an excellent corn silage crop, but we still had to apply much more water than for the forage sorghum,” he reports.
Overall corn silage production costs were about $250/acre, compared to $125-150 for the sorghum. He's waiting for the BMR silage nutritional readings from neighboring Mission Dairy, scheduled to start feeding the forage sorghum this spring.
Mike and Zeba Schouten opened the dairy early last year. They currently milk 3,100 cows, with a production average over 70 lbs/cow/day. The typical ration includes 52 lbs of corn silage and 8 lbs of wheat silage.
“We hope the BMR silage mixture can produce the same levels of milk,” says Mike, who put up an 18-month supply of silage in 2001-02. “We do things by the numbers and track any changes. If the results are good with the BMR, we could make it 50-100% of our silage needs.”
One strike against BMR sorghum is its reputation for lodging. But Bean says that varies among hybrids. In his tests, the average lodging rate of BMR sorghums was 11.8%, about 3 percentage points higher than that of conventional forage sorghums.
“Potential for lodging can be decreased by variety selection, keeping plant population down and taking care not to overapply nitrogen fertilizer,” says Bean.
Urbanczyk holds sorghum lodging down by not pushing for the highest yield. Also, he starts harvesting as soon as plant moisture content falls below 70%.
He says BMR sorghum requires much less N — 100 lbs/acre vs. 250 lbs/acre for corn. The seed is also less expensive.
“The seed cost for corn silage hybrids is $35-40/acre, compared to only $10/acre for BMR sorghum,” he says. “That's why we want this crop to work with the dairy. It will be better for us and better for the dairy that is seeking ways of cutting its feed costs without hurting its milk production.”