Farm Chemical Hazards Exposure Risks Rise Over Season

REGINA - Jun 27/05 - SNS -- Annual cereals produce more dry matter per acre when harvested at the soft dough stage, according to the Saskatchewan Agriculture and Food.

"There is more dry matter yield per acre in waiting to the soft dough stage before cutting. For years, we didn't know the answer. We assumed it amounted to more or less the same yield," Rangeland and Forage Agrologist Lorne Klein says.

In the summer of 2003, simulated grazing forage yields were collected from the Cool Season and Warm Season Annuals Forage Trial plots at Redvers and Indian Head. Annual spring cereals, which are seeded in spring, are one of the forage options available to livestock producers.

"Generally, there are two methods of harvesting a spring seeded spring cereal," explains Klein. "Either the crop can be grazed in the vegetative stage two to four times during the summer, or the crop can be allowed to develop to the milk/soft dough stage and cut once. After cutting, the windrow can be baled, chopped for silage, or left in the field for swath grazing."

Producers have questioned whether the cumulative dry matter yield of multiple grazing is similar to the single cut dry matter yield at the milk/soft dough stage. Saskatchewan research comparing dry matter yields of the two harvest options was not available. Research from Alberta from 1981-1983 had shown that simulated grazing yields are significantly less than single cut yields.

Research conducted in Saskatchewan in 2003 showed that simulated grazing yield of the cool season crops (oats, barley) averaged 59% of the single cut greenfeed yield. Further to that, the simulated grazing yield of the warm season crops (Golden German, Siberian Red, Strain R German, White Wonder) averaged 51% of the single cut greenfeed yield.

Tests were conducted again in 2004. Results indicated that simulated grazing of cool season crops yielded 50% of the single cut at the milk/soft dough stage, while simulated grazing of warm season crops yielded 45% of the single cut.

"We found that there was considerably less dry matter yield in the simulated multiple grazing plots, whereas on the plots where we waited an extra 35 days before harvesting the cereals, the yield far outweighed that."

Klein believes producers are going to think twice about seeding annuals to graze their cattle in the future.

Given the magnitude of the differences, producers wishing to graze annuals should consider allowing the crop to reach the greenfeed stage, and then windrow and swath graze.

Of course, harvesting costs and feed quality of simulated grazing and greenfeed need to be factored against the expected yield differences.