Testing of New Sainfoin Lines for Bloat-free Alfalfa Pasture Mixtures

Trial Site: Fairview Research Farm

Collaborator: Dr. Surya Acharya - Agriculture & Agri-Food Canada, Lethbridge

Research Coordinator: Dr. Akim Omokanye

From: Peace Country Beef & Forage Association 2016 Annual Report

Sainfoin is a perennial forage legume that does not cause bloat because of its condensed tannin concentration. The condensed tannin is very effective at preventing deadly pasture bloat in ruminants. Studies have shown that 15% or more sainfoin in alfalfa mixture can significantly lower, and in certain cases eliminates, the risk of pasture bloat. However, until recently, available sainfoin varieties have not survived well in mixed stands with alfalfa or have not regrown at the same rate after the first cut or grazing and so cannot be used with alfalfa for reducing pasture bloat. Recent studies have shown that new experimental sainfoin lines are more competitive and have improved regrowth rates compared to older sainfoin varieties. Sainfoin is said to be as nutritious and palatable as alfalfa, and more cold and drought tolerant.

In collaboration with Dr. Surya Acharya (AAFC, Lethbridge), PCBFA tested some experimental sainfoin lines (LRC 3900, LRC 3901 & LRC 3902) in mixtures with AC Grazeland alfalfa variety to evaluate their growth, persistency and forage yield. The experimental sainfoin lines were developed by Dr. Surya Acharya. The tests were to help us determine if these experimental sainfoin lines developed for their ability to survive with alfalfa could outperform an older sainfoin variety called Nova. One of the experimental sainfoin lines (LRC-3902) was recently re-leased as AC Mountainview by Dr. Surya Acharya.

Methods

Three experimental sainfoin lines (LRC05-3900, LRC05-3901, LRC05-3902) along with an older sainfoin variety called Nova (check) were each seeded in mixtures with AC Grazeland alfalfa on May 23, 2013 at the Fairview Research Farm (NW5-82-3W6) on RR #35. Both sainfoin and alfalfa were seeded in the same row (same row mixtures). AC Grazeland alfalfa is a low-bloat potential alfalfa, because this variety results in a slower initial rate of digestion, which helps prevent the onset of bloat. The soil at the test site had a pH of 5.4 and 8.8% organic matter before seeding. Each mixture was seeded with 15 lbs/acre of sainfoin and 6 lbs/acre of AC Grazeland alfalfa, indicating that half of the usual recommended seeding rates were used for both legumes. The 4 treatment mixtures were replicated 4 times in small plots, which had been arranged in a randomized complete block design. Seeding was 0.5-0.7” deep, and the seed was inoculated. We applied 40 lbs/acre of 11-52-0 at seeding in 2013. Assure II and Basagran Forte were used to control volunteer oats & canola and other broad leaf weeds in the seeding/establishment year (2013).

Cutting was done twice yearly from 2014 to 2016. The first cut was when sainfoin was at 40-50% bloom (alfalfa was at 20-30% bloom) and mostly from June 20-23 every year. The second cut was at 6 weeks after the first cut. Please note that the highest risk of bloat occurs when legumes are in the pre-bud or vegetative stage. In 2015, only one cut was possible because deer had selectively grazed down all sainfoin stands in the mixtures just before the second cut was to be taken. From 2014 to 2016, forage dry matter (DM) yield and percent composition (proportion) of sainfoin and alfalfa in the mixtures were determined. In 2016, second cut was done on August 2. Rainfall received at the site from April 1 to August 31 was 9.516” (2013), 4.944” (2014), 6.726” (2015) and 13.504” (2016).

Results Obtained and Implications

Forage Dry matter yield (Figure 1)

In general, DM yield at any particular cut was statistically similar for the sainfoin - alfalfa mixtures in 2014, 2015 or 2016. In 2014 (one year after seeding), DM yield was generally lower for the 2nd cut (1143-1495 lbs DM/acre) than 1st cut (3114-3685 lbs DM/acre). The lower DM yield obtained for the 2nd cut in 2014 was due to low moisture. In Fairview and area, 2014 was a very dry year.

Overall, from 2014 to 2016, including any particular sainfoin in the legume mix did not appear to reduce yields.

Proportion of Sainfoin and alfalfa in the mixtures

The proportions of sainfoin in alfalfa mixtures at every cut are shown in Table 1. Generally, except for Nova sainfoin in 2016 (which had 5-6% sainfoin in the mixtures), sainfoin formed 18% or more of the total forage composition. Overall, the 3 experimental sainfoins produced higher proportion of DM in alfalfa pasture mixtures than Nova. The 3 experimental sainfoins consistently formed 20% or more in the mixtures. This is important because at least 15% sainfoin needs to be present in the alfalfa stand to avoid bloat.

Compared to the 3 experimental lines, the drastic drop in the proportion of sainfoin for Nova from a mean of 22% in 2014 to a mean of 6% in 2016 (Figure 2) probably confirms that an older sainfoin variety such as Nova would not be as competitive as the new sainfoin in alfalfa pasture mixtures.

Overall, LRC-3900, LRC-3901 and LRC-3902 dropped by 14, 11 and 8% over the 3 years of cut. Nova dropped by 16% over the same period. Our study further shows that when seeded with alfalfa, the experimental sainfoins should be able to provide bloat protection for more growing seasons than Nova or other older sainfoin varieties.

Conclusion

Our results show that Nova sainfoin may not be good competitor with alfalfa in pasture mixtures compared to any of the 3 experimental lines. As indicated earlier, studies have shown that 15% or more sainfoin in an alfalfa pasture mixture would significantly lower, and in certain cases eliminates, the risk of bloat. Our study here at the Fairview Research Farm, indicates Nova sainfoin, which contained only 6% in 2016 in alfalfa pasture mixtures may not have the potential to lower bloat a few years after seeding.

One (LRC05-3902) of the 3 experimental sainfoin lines used in this study has been released as AC Mountainview sainfoin. The use of AC Mountainview sainfoin variety in alfalfa pasture mixtures is recommended.

Some Tips to Manage Bloat (Extracts from AAF: Feeding Legumes to Cattle, Agdex 420/62-1)

• Use non-bloating legumes such as cicer milkvetch, sainfoin and birdsfoot trefoil. Be aware, these forages are not as good as alfalfa in terms of yield, re-growth and persistence in the stand.

• Low-bloat potential alfalfa - AC Grazeland. This variety results in a slower initial rate of digestion, which helps prevent the onset of bloat.

• Legume-grass mixtures - improves animal and pasture productivity as well as managing bloat. When legumes are planted with grasses, their presence can improve animal performance by as much as 30%, and even more when seeded in pure stands.

• Products or supplements to manage bloat - AlfasureT, Bloat Guardr (Poloxalene) and ionophores.

• NEVER move hungry cattle into legume pastures in the morning.

• Put animals out to pasture in the afternoon, so plants have a chance to dry off.

• Feed another source of dry roughage (long fibre) before grazing bloat-causing legumes.

• Maintain a uniform and regular intake of forages. Once cattle have started grazing, leave them on the pasture, even at night.

• When animals are first put on pasture, check them at least twice a day. Some animals are chronic bloaters. Watch for these animals, and remove them from the pasture if needed.

• Graze full bloom mature plants.

PCBFA On-going High Legume Pasture Project with Sainfoin

Collaborator: Conrad Dolen, Fourth Creek

PCBFA is part of a two-year province wide field scale trial (10 acres) to showcase the potential of sainfoin in a high-legume pasture mix. Our site is at the Dolen’s in Fourth Creek. A high legume pasture mix (60% legumes, 40% grasses) was seeded in 2016. AC Mountainview sainfoin variety was used in the mixture. PCBFA is planning a field day at the site in summer 2017 to highlight the project.

For more information on the province wide High legume Pasture Project with Sainfoin, visit: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/faq14389