Ostertagia and liver fluke

A mild winter coupled with a wet spring has produced fantastic conditions for growing pasture this season; however, this has also encouraged favourable hatching conditions for gastrointestinal parasites.

It is possible grazing cattle have picked up a greater number of infective larvae, which is likely to result in higher worm burdens in autumn.

With this in mind, and prior to summer drenching of stock, now may be a good time to speak with your animal health adviser and evaluate your strategic control program for the coming year.

There some of the key factors to consider in the management and control of the small brown stomach worm, Ostertagia ostertagi, and liver fluke, Fasciola hepatica.

Ostertagia ostertagi is the most production-limiting parasite; particularly in weaners, yearlings and heifers.

According to MLA (2005) the net financial benefit of Ostertagia control alone in growing cattle suggest gains of $3000-$8000 for a 100cow herd.

Control of worms, particularly in younger stock, is achieved through a combination of grazing safe pastures to limit the ingestion of larvae, monitoring worm burdens through faecal egg counts (FEC), and drenching cattle strategically throughout the year to kill worms at optimal times and minimise the risk of parasite resistance to drenches.

Ostertagia live in the lining of the fourth stomach of cattle, destroying the stomach tissues and glands and inhibiting the digestion of nutrients.

The eggs are passed in the faeces and hatch as dung pats begin to dry.

Ostertagia develop through three larval stages, before migrating up the pasture leaves where they can be ingested by cattle.

The infection and damage caused as larvae mature is categorised as either type one or type two Ostertagiasis.

Type one is caused by the ingestion of large From the team at Claas Harvest Centre Gippsland, we would like to thank all our customers for their continued support in 2016. Through a busy harvest season we have enjoyed working with you and understand that excellent customer service leads to long term customers and new business. In 2017 we are implementing more innovative ways of delivering excellent aftersales service. Our Harvest Centre in Gippsland is supported by many of Warragul’s local businesses who assist with the daily operation of our services. We would like to acknowledge the efforts and support from the Warragul Business Group, Trac Mac Farm Equipment, McNeil Transport, Metal Form Industries, Ace Industrial Supplies, Warragul Machinery and Mechanical, Henry’s Truck & Trailer Pty Ltd, Warragul & Drouin Gazette, BJ Bearings, Legible Signs, Young’s Refrigeration, Farm Depot Warragul, Olsson’s Transport and the many services that have helped us along the way. Agriculture is the foundation of everything we do on this planet. Our farmer’s products impact every major industry, not only in this country, but across the globe. Farmers are our hard working community who don’t always receive acknowledgement for the long hours, tough working conditions and supplier demand. So to all our farmers, contractors and support groups, thank you for everything you do! numbers of larvae within a short period and the subsequent maturation of these larvae.

It is more common in young cattle, particularly weaners.

Type two occurs as the arrested larvae break dormancy simultaneously; causing damage as thousands of worms mature at once.

Pastures can be managed to minimise the contamination of infective larvae, creating safepastures for younger stock to graze.

This generally requires using low risk pastures with long periods of rest between grazing, such as pastures that have been cropped or cut for silage and hay.

Alternating with sheep is also used, as the major worm burden in sheep and cattle are different.

Yearling cattle are the ‘worm egg generators’ as they have little resistance to the development of the worms.

Older cattle shed fewer worm eggs, so calves and weaners should not follow yearlings on pastures.

For weaners and yearlings it is advised that these stock are routinely drenched/treated at weaning (December-February for autumn-drop calves).

Adult cattle generally develop an immunity or resilience to worms. Unless adult cows are in a high stocking rate system and/or within higher rainfall zones (+600mm annual rainfall) routine treatment should not be required after their second calf.

Areas of lying water can be a major contributor to liver fluke infections in cattle.

Liver fluke requires wet environments and an

Market report for 4th and 5th January Wednesday Fat Sale 369 head. Thursday Cow Sale 35 Bulls, 238 Cows.

The new year started with a lighter than expected yarding of 369 head for the fat sale and prices remained steady on the previous sale for most categories. Bullock, heifer and steer numbers still remain on the lighter side with condition mixed. Lighter steers failed to fire and pulled their average back 10 cents. Vealers sold strongly in the better pens with only a few secondary pens on offer. This week’s yard average remained firm on the previous sale at 320 cents per kilo. 2 bullocks made to 269.2, to average 269.2. 29 heifers made to 325.2, up 18 and averaged 315.8 25 steers made to 330, up 15 and averaged 269.7, back 10.

313 vealers made to 360, back 17 and averaged 328.8, back 4.

On Thursday the bull and cow sale saw good competition force prices upward. 35 bulls topped at 291.2, to average 9 cents better at 251.2. There were 238 cows yarded with the top selling to 279.2, and averaging 6 cents up at 223.4, with the yard average 4 cents up at 227.8.

2 LimX I&G Parkin, Thorpdale 370 360.0 2 LimX J Vicary, Drouin 348 360.0 1 LimX P&H Hatswell, Neerim Est 380 358.0 1 R/Ang E Lambourne, Tyers 385 352.2 2 LimX K&L Young, Ellinbank 405 352.0 1 Char R Stipani, Willung Sth 475 351.6

6 Ang 4 SimX

16 Char 7 Ang

2 AngX D Stoll, Buln Buln 1 Lim N Rysko, Mt View 3 CharX M Romanin, Warragul Sth 1 Fleck R&C Monk, Poowong 1 Ang A&H Rhodes, Darnum

8 Frn 1 Frn

1 Bld 1 Bld 1 Ang 1 Frn 1 Frn

R&R Gray, Torwood W Miller, Rokeby

P&S Gardiner, Warragul R&R Gray, Torwood

M Romanin, Warragul Sth 666 239.2 1593 J Pratt, Darnum

S Granieri, Warragul Sth 925 291.2 2839 C Bragagnolo, Trafalgar 800 283.6 2268 Stanvale Farm, Neerim Est 845 278.2 2350 G&B Geary, L/warry Nth 985 264.6 2606 Jayanal, Longwarry 820 258.2 2117

1. Landmark, 2.

SEJ, 3. Gibbon, 4. Elders, 5. Scotts.

478 326.6 493 309.6

452 325.2 436 315.6

1332 1252 1360 1355 1425 1670

1562 1524

1468 1375

565 279.2 1577 680 277.2 1884 650 265.2 1723 550 258.6 1422 550 243.2 1337 555 279.2 1549 intermediate host, the small freshwater lymnaeid snail to survive and complete its development.

Adult liver fluke in the bile ducts of sheep and cattle, can produce up to 50,000 eggs per day which are passed in the faeces.

The eggs require wet conditions to hatch and separate from faecal matter in which the first larvae, or miracidium, emerge.

Within three hours the larvae must locate and invade the lymnaeid snail.

The first larvae bores into the host snail and undergoes three development stages where it also multiplies and emerges as a cercaria. Up to 600 cercaria can develop from one miracidium and these form cysts on pastures that become the infective larvae.

When ingested by sheep, cattle or other animals, these cysts break open in the intestines and the immature flukes burrow through the intestinal wall and into the liver.

Damage to the intestines and liver caused by a large number of migrating immature fluke is known as acute liver fluke disease.

It is more common for cattle to be affected with chronic liver fluke disease with symptoms including weight loss, reduced growth rates, reduced milk production, anaemia, oedema and diarrhoea.

Ingestion of infective larvae is usually greatest in autumn and summer in irrigated or wet areas as the cattle graze the wet ‘flukey’ areas which are the main source of green pasture.

Acute liver fluke disease can occur in late spring and early summer in heavily infested areas and a drench at this time may be required.

A summer fluke drench should only be administered to cattle on high-risk areas/properties and when the presence of fluke is determined in consultation with a vet.