Perennial ryegrass toxicosis = potential summer risk

Most old or naturalised perennial ryegrass pastures contain fungal endophytes which can produce high levels of alkaloids that can be toxic to livestock.

Agriculture Victoria senior veterinary officer Robert Suter said the symptoms are collectively called perennial ryegrass toxicosis (PRGT) and cover a range of nervous disorders including staggers, ill thrift, heat stress, scours and possibly lower fertility.

Serious outbreaks occur in high rainfall areas across Victoria when big springs are followed by a hot and dry autumn.

Dr Suter said in 2002 it was estimated 90,000 sheep and 500 cattle died from direct causes of these alkaloids and a similar number from indirect causes.

The key indicators of high risk to animals (this includes sheep, cattle and alpaca) were identified as:

A dominance of perennial ryegrass in the pasture (with wild type endophyte)

A big spring with high rainfall in spring-summer that prolonged the length of the growing season

This was followed by dry conditions in March and high average maximum temperatures in March (23 degrees Celsius) and April (20 degrees Celsius).

While the forecast for autumn is not currently predicting hotter and/or drier conditions than usual, much of Victoria has experienced abundant spring growth. If you have experienced severe issues in the past, it is worth considering now what you might do to reduce the impacts this time. These would include: Assess each paddock on the farm for the risk of PRGT (knowledge of past effects).

Identify which paddocks shouldn’t be grazed by susceptible classes of stock (young sheep or cattle or breeding ewes) in the high risk period. If this is a high proportion of paddocks then consider using stock containment areas for joining ewes if spring lambing, and weaners.

Limit time stock spend grazing high risk paddocks; minimise seed head production and access to seed heads.

Ensure access to plentiful water with a low risk of drowning.

Supplementary feeding on high risk pastures is unlikely to reduce the risk, and may worsen the staggering.

For the long-term, consider resowing pastures with other pasture species (e.g. phalaris or fescue) or other ryegrass cultivars that have animal ‘safe’ endophytes but still have persistence attributes for the plant.

Market report for 11th and 12th January Wednesday Fat Sale 373 head. Thursday Cow Sale 71 Bulls, 313 Cows.

With a lighter than expected yarding of 373 head, same as last week for the fat sale, and prices were up on the previous sale for most categories. Heifer and steer numbers still remain on the lighter side with condition very good and vealers sold stronger.

This week’s yard average remained firm on the previous sale at 320 cents per kilo. 34 heifers made to 330, up 5. 25 steers made to 339, up 9 and averaged 304.2, up 20. 298 vealers made to 379, up 9 and averaged 334.3, up 4. On Thursday the bull and cow sale saw good competition force prices upward. 71 bulls topped at 314.6, up 22, they averaged 258.1. 313 cows yarded with the top selling to 300.2, which is 21 better and averaging the same as last week at 222.4, with the yard average 4 cents up at 230.4.

1 Baz 3 LimX 7 Ang 1 LimX 1 Char 1 LimX 7 LimX

2 Char 2 Ang 1 R/B

B/B

4 Char 3 Char

1 B/B 1 Hfd 3 Lim 1 Lim 1 Ang

1 Frn 3 Frn 1 Frn 1 Frn 1 Frn 8 Frn

1 Lim 1 Lim 1 Hfd 1 Hfd 1 Frn 1 Frn

Linderbrook Past, Bunyip 335 371.6 I&G Parkin, Thorpdale 370 366.0 G&L Bennett, Trafalgar 379 362.6 E&R Crowe, Narracan 415 360.6 I&A Hancock, Poowong 405 360.0 Batty & Ferguson, BB/East 415 355.0 C&K White, Yannathan 365 352.0

S Colbourn, Nilma LL&HM Wigg, Heyfield A Moyes, Boolarra Mrs M Kimbar

M McInnes, Trafalgar G & Mr Stephens, N/B

P&J Keily, Trafalgar R&J Pretty, Jindivick A&L Griffin, Lardner JF Britt, Lillico AM&PE Laidlaw, Tan/Sth

J&H Harvey, Yarragon McFox P&L, Modella RS Coster, Cloverlea Orvale Past, Darnum RW Hope, Catani J McCauley, Cora Lynn

A&L Griffin, Lardner JF Britt, Lillico I Manson, Newry R&J Pretty, Jindivick T Smethurst, Athlone Jayanal, Longwarry

3. Landmark, 4. Scotts, 4. NGL.

1224 1356 1375 1494 1438 1473 1284

448 331.6 1483 508 327.3 1661 545 322.0 1754 540 322.0 1738

549 325.6 1788 500 319.6 1598

535 300.2 1606 515 298.6 1537 660 267.2 1763 615 267.2 1643 645 265.0 1444

705 245.0 1727 666 243.6 1623 780 242.6 1892 755 242.0 1827 670 242.0 1621 671 232.0 1556

850 305.2 2594 735 301.2 2213 1160 290.2 3366 850 269.6 2291 1025 264.2 2708 810 257.2 2083 1. Elders, 2. SEJ,