Non-bloat legumes show promise in pastures

Incorporating non-bloat legumes into pasture stands could rejuvenate pastures and lead to better average daily gains, according to a three-year study at the University of Saskatchewan.

Bree Kelln undertook the study, planting cicer milkvetch and sainfoin varieties into sites at Lanigan, Sask., and Lethbridge in 2015.

She presented Lanigan results at the Saskatchewan Beef Industry Conference in January.

Kelln said there wasn’t a lot of research on these two particular legumes, how they would fare if introduced into an existing pasture and whether they would provide adequate forage.

“Overall, we found that the quality of these sod seeded non-bloat legumes really did meet the requirements of growing steer calves,” she said. “We were able to see increased weight gains on those pastures, as well as economic returns.”

There was also a decrease in enteric methane emissions from the cattle.

The Saskatchewan work was done on a 75-acre pasture split into 15 five-acre paddocks. The pasture was 13 years old.

A half-litre of glyphosate was applied twice to set the stand back, and then some of the paddocks remained control sites and others were seeded to either sainfoin or cicer milkvetch at the recommended rates of 23 pounds per acre and 15 lb. per acre, respectively.

The crops were seeded in a shallow bed with minimal disturbance, Kelln said.

In 2016, 60 steers were grazed, while the following two years only 45 were able to graze due to drought.

Kelln said 82 days of grazing the first year were followed by just 20 days in 2017 and 48 days in 2018.

She said the legumes established well at first.

“The cicer milkvetch really did quite well. It increased in the stand to close to 25 percent in 2017, then a little bit of a decrease in 2018, but really it was able to maintain its population under those four years of a grazing situation,” she said.

The sainfoin started well and then steadily declined.

Kelln observed lower dry matter intake with the cicer milkvetch and sainfoin, but higher average daily gains.

The ADG on the legume pastures was 2.3 lb. per day compared to 1.9 lb. per day on the control, she said.

“That’s a 20 percent increase,” she said. “It’s not statistically significant but I think it shows the benefit of having those legumes in that stand.”

She also saw lower methane production. Methane production comes from enteric fermentation that naturally occurs in the rumen and is proportional to dry matter intake, she said.

Kelln also said the cost per acre to seed the legumes, amortized over the suggested typical 10-year life of a pasture, was $24.49 for the cicer milkvetch and $21.97 for the sainfoin.

Net returns were $103.29 per acre for the cicer milkvetch, $109.93 for the sainfoin and $89.53 for the control.

Kelln said more detailed results on digestibility, methane production and what happens when different ratios of legumes are included in the stand will be available later this year.

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