SOUTHERN Scientific Services principal, Larry Walker has expressed concern there is a very high danger to livestock of staggers from perennial ryegrass and phalaris as well as the risk of phalaris sudden death syndrome.

The Hamilton-based Mr Walker undertakes pasture toxicology testing at his Port Fairy Road laboratory, as well as water quality and antibiotic meat withholding tests, and said the unusually dry late summer and autumn, coupled with the falling temperatures in late May, were the perfect conditions for these problems.

He said that there were two types of grass originated staggers, one from Perennial Ryegrass (lolium perenne) and the other from Phalaris (phalaris aquatica).

On top of these, there were two types of Phalaris Sudden Death Syndrome: Phalaris polioencephalomalacia-like sudden death syndrome and (PED) and Phalaris cardiac-sudden death syndrome (PCD).

Mr Walker told The Spectator that in late May 2013, in a similar season to that at present, there had been some severe cases of Phalaris Death Syndrome, especially in the Cavendish area.

He added that the last major outbreak of Perennial Ryegrass Staggers (PRGS) was in 2002 when there was a late autumn break after a good spring and summer of growth.

Perennial ryegrass staggers (PRGS)

PRGS is poisoning by Ergovaline (an LSD-related neurotoxin) which is contained in Perennial Ryegrass.

These toxins are produced by the endophytic fungus neotyphodium lolii which can be present in all parts of the grass plant, but tends to be concentrated in the lower part of the leaf sheaths, the flower stalks and seeds.

This condition can affect horses, cattle, sheep, farmed deer and alpacas.

Agriculture Victoria has advised: “PRGS is usually observed as temporary incoordination (hence the name ‘staggers’) in sheep and cattle. This occurs when endophytes…are established in older stands of perennial ryegrass pastures. The(y)…produce a toxin that protects the plant from insects and helps with establishment, but also interferes with the nervous system of sheep.

“Sheep, cattle and horses are all susceptible; however, PRGS is usually seen more in younger animals. Weaners should be closely monitored during this time.

“PRGS develops within 7–14 days of the ingestion of toxic pasture.”

Phalaris staggers (PS)

LOCAL Land Services NSW states: “Phalaris staggers (PS) is caused by ingesting green, actively growing phalaris at a time when the grass contains a high concentration of toxic alkaloids, generally in autumn during the first re-growth or after periods of pasture stress following frost or water stress.

“It usually takes a minimum of 10 days grazing on phalaris for staggers syndrome to develop. Most cases occur after one to two months of grazing”.

“First signs are usually fine tremors of the head. More severe signs are seen with exercise or under stress, such as mustering. These include stiff movements and incoordination, often resulting in collapse with stiffly extended limbs. “The ingested toxin can also induce high body temperatures, so sheep may try to cool themselves in dams and troughs, sometimes drowning or otherwise injuring themselves in the process.

“There is no specific treatment for PRGS. It is best to remove an affected flock from the source of the problem by moving them quietly (without a dog) into another paddock. It is important to avoid stressing affected stock, as this will worsen their condition. Animals will recover once removed from the pasture for one to two weeks. Cases will cease following a significant break in the season and onset of cooler weather.

“If exposure to toxin is prolonged, permanent neurological damage can occur.”

The alkaloids guilty of causing PS have complicated names such as DMT, 5-MeO-DMT, and 5-OH-DMT (also known as Bufotenine, an ingredient of the cane toad’s skin-borne poison).

Mr Walker said that these chemicals happen to be similar in nature to those favoured by South American Shamans in the psychoactive brews used in their ceremonies.

Phalaris Sudden Death Syndromes (PED & PCD)

THESE two syndromes, PED and PCD are more mysterious than Phalaris Staggers, the exact cause or causes remaining unidentified.

Included in a summary of PED and PCD from Local Land Services NSW is the following information:

“Phalaris sudden death is thought to be a completely separate syndrome to ‘Phalaris staggers’. The sudden death syndrome also occurs in autumn to early winter, but occurs within 36 hours of introducing stock onto phalaris pastures.

“The sudden death syndrome is poorly understood. It is proposed to occur as a result of ingesting a compound in phalaris that decreases nitrogen metabolism, resulting in peracute ammonia poisoning.

“The polioencephalomalacia-like (i.e. PED) sudden death syndrome occurs in autumn to early winter within 12-36 hours of introducing stock onto pastures with new phalaris growth.

“The first six weeks post autumn break after a dry season is the most risky period for phalaris PED-like sudden death.

“The toxins in the grass result in animals presenting with high levels of ammonia in their system. It takes stock 24 hours to develop effective nitrogen metabolism on phalaris.

“Phalaris cardiac-sudden death (PCD) outbreaks may occur as soon as 24 hours following introduction to the pasture, however in some reports sheep had been grazing the toxic pastures for 2 weeks before outbreaks occurred.”

Pre-autumn break water tank advice

IN addition to his concerns about pasture feed, Mr Walker said water tanks and collection pipes were worth checking before the rains come, as the extended dry break has potentially given opportunity for the plumbing to be “clogged with ugliness” that just “stews away”.

He said he has fielded calls after a burst of wet weather where “all it did was wash all the really nasty (stuff) … and spit it in the tank without any follow up volume to dilute it out”.

“If you’ve got a system where it’s a wet-connect (where it) comes up the side of the tank, usually at ground level on the riser, there’ll be a screw cap installed - all you do is pop the screw cap off, let it all drain out and put the cap back on,” Mr Walker said.

“What I’ve actually suggested to a few people when they’ve got enough tanks, is take the cap off and leave it off, put a bit of mesh on there so nothing crawls in there (and) magnifies the problem.”

While farmers should take the advice of qualified professionals in managing the risks and, heaven forbid, occurrence of these outbreaks, Larry Walker’s clarion call should not be ignored.