Juan N. Guerrero said the lack of a defined, uniform grass hay standard for these tropical species impairs the production from them of consistent, export-quality hay. During the recent 31st California Alfalfa & Forage Symposium in Modesto, he said the three species of grasses, when exported to the Orient, are judged solely by color, texture, weediness and other subjective means. No chemical tests other than that for nitrate content are required.
"To further cloud the issue," Guerrero added, "the final country of destination may have its own set of standards. Different hay trading companies from the same country may have different hay grading standards, and different geographical areas of the same country may also have differing hay preferences."
Green, soft hay has always been prized by the U.S. livestock industry, Guerrero noted. For the export trade, green-colored bermudagrass and kleingrass hays are also valued. But in certain areas of Japan sudangrass buyers prefer a nitrogen-deficient and thoroughly bleached product, counter to both maximum yields and economics for the grower.
He suggested that a test developed from well-defined research might show some connection between hay color and nitrate levels in sudangrass hay. Stem texture could be detected by the existing acid detergent fiber (ADF) test.
During 2000, Imperial County had 42,000 acres of bermudagrass and 55,000 acres of sudangrass, while kleingrass, a new crop, made up about 20,000 acres in the Imperial and Palo Verde Valleys and in Arizona along the Colorado River.
Citing interviews with Imperial Valley hay brokers, Guerrero said more than half the hay from the three grasses is exported. The lack of consistent standards for quality means that grading is generalized and may not apply to any one transaction.
Bermudagrass has hay, seed, and straw segments, and, depending on the price of seed, as much as half the Imperial Valley acreage may be allocated to seed production. About 10 to 15 percent of the acreage produces domestic-market horse hay.
Export bermudagrass hay has a grading system based on fiber length, texture, color, weediness and "rerake." Hay not meeting a C grade goes to the domestic market.
Rerake, Guerrero explained, is the portion of hay left in the windrow by the baler. It remains in the field and after flood irrigation turns brown. In subsequent cuttings it mixes with fresh, green hay, creating a discolored bale of diminished value.
Bermudagrass hay is gaining acceptance by the horse market, which requires it to have green color, no weeds, and bales weighing 75 to 100 pounds.
Giant bermudagrass, favored because of its longer fiber length, is put up as hay rather than common bermudagrass.
Kleingrass, he said, came to the Sonoran Desert about six years ago. It has a market in the Orient but has been dogged by palatability problems. On the other hand, in the southwestern U.S. beef range cattle relish kleingrass pasture.
Kleingrass hay is graded by texture, color, plant maturity, and weediness. Weed contamination will exclude it from export. Guerrero said about 20 percent of the volume fails to meet export grade and goes into the domestic market, mainly for dry dairy cows and beef feedlots, which, he warned, "may contain weeds, be rained-on, be off-color, and contain rerake."
Grades for kleingrass hay vary as to country of final destination, said Guerrero. Under certain growing conditions, according to reports from Texas, it can contain toxic saponins, which cause problems for sheep and horses but not cattle. "These saponin problems have not been reported under the drier, irrigated conditions of the Imperial Valley,’ he said.
Most sudangrass grown in the Sonoran Desert, where it has been a crop more than 40 years, goes to export. About 20 percent of the crop, or the portion from later cuttings, finds its way to domestic dry dairy cows, beef feedlots, zoos, and Mexico.
It may contain weeds, hard stems, and high nitrate content. No chemical test other than a nitrate test is required for export, but grade is determined by a subjective evaluation of weediness, stem thickness, and color.
"California hay producers are at the mercy of ill-defined, subjective grass hay export grades with no regard to objective chemical analyses," said Guerrero, who added that grass hay standards jointly developed by U.S., Japanese, and Korean scientists could benefit both the California growers and importers in the Orient.