And that chemical causes ryegrass staggers in livestock. A major pain and loss of production and profit in my early years of farming, but something I haven’t seen much of for the last decade or two until recently.
I had thought one of the reasons for that is that I’ve bred my sheep to be facial eczema tolerant and that tolerance also conferred tolerance to other fungal toxins. Now, I’m not so sure about that.
Back in the 1980s, we were complaining that our new ryegrass pastures weren’t lasting. Even then they were relatively expensive to establish and if they were only lasting a year or two, it was a waste of money. And money was very tight.
I had a discussion with a plant breeder and told him that my definition of perennial was a plant that lasted an indefinitely long time. He reckoned it was a plant that lasted more than two years.
The nearby Takapau Research Station, ably led by Mike Slay, did some sterling work on why our ryegrasses weren’t persisting and discovered that it was Argentine Stem Weevil (ASW) that was taking them out. They had thought the main problem was grass grub. Then they found that many of the seed lines being sold to us didn’t have the endophyte that protected the ryegrasses from ASW and with that knowledge, I started sowing a locally-bred cultivar called Droughtmaster.
It was terrifically persistent and caused unbelievable ryegrass staggers in the late summer and autumn.
The next bit of research from the station was that it was the endophyte, or more particularly Lolitrem B, that was causing the staggers, so we were faced with either having grasses that wouldn’t persist but didn’t give staggers or putting up with the staggers. Then they gave us some decent management advice about not grazing too low into the pastures in the autumn, as this was where the endophyte was concentrated so we learned to keep stock rotating.
Then a couple of years later, the scientists discovered that it was a chemical produced by the endophyte called peramine that conferred protection of the ryegrass to ASW and probably other insects.
Why not serve us up an endophyte that had peramine in it but not Lolitrem B, we all thought? And that’s exactly what the clever scientists did, and we were able to use ryegrasses with the novel endophytes in them which didn’t cause staggers but protected the plants from insect damage.
Another lot of clever scientists bred up and released a parasite which preyed on ASW, further helping us out.
Over the years, we take a lot of these excellent science outcomes for granted, so next time you come across a scientist, give them a hug. Covid levels allowing.
Mind you, last year I ended up with terrible staggers for the first time in a long time on some new grass paddocks with AR37. These swards were recovering really well from the drought due to their insect tolerance compared to the rest of the farm proving their worth. But it turns out that in particular circumstances, AR37 can induce bad staggers and it did.
Ironically, I’m using those same paddocks this year as ‘hospital’ paddocks as the old resident pastures full of the original endophyte have brought on staggers again.
I’m surprised because after the ravages of the drought and then losing control after the good November rains as I destocked, they look more dominated by rubbish grasses like browntop, dogstail and the like. But there must be older ryegrass in there than it appears.
Because the ewes are in such good order, I’ve been asking them to clean up some of these paddocks in the lead up to tupping, so the poor things have had their faces buried down in the base of the swards.
I haven’t lost any yet, but find myself carting the worst affected four at a time in my little motorbike trailer to the novel endophyte paddocks, which also include AR1 strains of endophyte, so that hopefully they get over it before the ram turns up and they get all excited and topple over during mating. It’s no easy matter dragging 65 or 70kg ewes to the trailer, but at least they aren’t hard to catch.
The problem being that the Lolitrem B (trem for trembles) is stored in the fat of these good conditioned ewes and takes some time to dissipate.
I’ve said it before and will do so again: if farming were easy, everyone would be doing it.
