Five spring-seeded winter annuals went head-to-head in three years of simulated grazing trials at three Agriculture and Agri-Food Canada sites in three different growing zones in Saskatchewan.
The Swift Current site represented the brown soil zone; Saskatoon, the dark brown soil zone; and Melfort, the grey-wooded/ black soil zone.
The varieties were CDC Buteo winter wheat, Bobcat winter triticale, Prima fall rye, Botrus Westerwolds ryegrass and Italian ryegrass.
The result was a tie in total digestible nutrients (TDN), but Westerwolds lagged behind the rest in terms of crude protein (CP). Westerwolds ryegrass had the clear yield advantage in the Parkland area, while winter wheat was the most productive in the drier, brown soil zones. An economic analysis showed that, across the three sites and all three years, winter wheat was the most profitable crop for grazing and Westerwolds was a close runner-up.
The plots were sown in May and clipped for the first time when the Westerwolds ryegrass was heading, generally the last week in July. The second clipping was taken when there was about 10 inches of regrowth. This ranged from mid-August to early October, depending upon growing conditions. When possible, third cuts were taken just before freeze-up. The yield results are given in dry matter tonnes per hectare (DM t/ha). If you prefer tons per acre, multiply by 0.446.
At Swift Current, winter wheat produced the highest first-cut yield. The three-year average was 3.2 DM t/ha. Westerwolds ryegrass and winter rye were close seconds. On the second cut, winter wheat produced slightly more than Westerwolds, Italian and winter rye. There was only one third cut. Winter triticale produced the most, while Italian ryegrass had the poorest yield. Overall (total of all cuts), winter wheat produced the most forage, averaging about 5.5 DM t/ha per year, and Italian ryegrass produced the least forage, averaging about 4 DM t/ha per year during the three-year trial.
The overall standings were the same at Saskatoon, with total average yields being equal to or higher than those at Swift Current. The first cuts on winter wheat averaged 3.1 DM t/ha through the three years. Winter rye and winter triticale were nearly as productive as winter wheat on the first cuts while winter triticale was the runner up to winter wheat on the second cuts. While Italian ryegrass produced the least on the second cuts, it produced the best third-cut yields in the two years when a third cut was possible. Winter rye had the poorest third-cut yield.
At Melfort, Westerwolds ryegrass yielded the most on the first cuts, averaging 4.0 DM t/ha. The first-cut yields of the other species were similar to each other. Westerwolds produced the most forage on the second cuts as well, followed by Italian ryegrass, while winter rye produced the least. There was only one third cut and both ryegrass varieties showed the best yields. Again, winter rye had the lowest yield. Overall, Westerwolds ryegrass produced the most forage each year — close to 10 DM t/ha — and winter rye the least, at just under 6 DM t/ha.
All species had excellent TDN (70 to 75 per cent) that would support very good gains on yearlings and calves. Westerwolds had slightly lower TDN and CP than the other species at the Saskatoon and Swift Current sites. The CP ranged from 23 to 28 per cent.
At Melfort, the CP levels were much lower all around, ranging from 11 to 15 per cent, with Westerwolds being the lowest. However, that’s still on the high end of CP levels of perennial grasses.
It was expected that Westerwolds would have a lower CP level than the others because the first clipping was timed for the heading stage of Westerwolds when the other species were still in the vegetative stage. Westerwolds ryegrass is a spring annual that does produce seed in the first year, whereas Italian ryegrass is a biennial that doesn’t survive prairie winters to set seed. Winter cereals won’t head out and set seed until after they have been exposed to low temperatures.
The forage quantity and quality data was entered into the Cowbytes 4.6 program to predict gains on animals grazing these winter-seeded annuals.
The modelling showed that either of the ryegrasses would produce more pounds of beef per acre than any of the winter cereals in areas with soil and growing conditions similar to those at Melfort. Conversely, any of the winter cereals would produce more beef per acre than either of the ryegrasses in areas similar to Swift Current and Saskatoon.
All five forages showed potential to yield more pounds of beef at Melfort than at the other two locations. The projection showed that Westerwolds or Italian ryegrass would support gains of 1,000 pounds per acre and the other varieties would support gains of about 800 pounds per acre. At Swift Current, top gains of 600 pounds of beef per acre could be possible with winter wheat or winter rye. Winter wheat or winter triticale could produce gains of 600 pounds per acre in areas similar to Saskatoon.
The project summary was published last year. The fact sheet can be viewed at www.wbdc.sk.ca.For more information, call Paul Jefferson at 306-682-3139.