Scientists examine ryegrass nutrients

Agriculture Victoria research scientists have developed a quicker and more costeffective way to measure the nutritive value of thousands of individual ryegrass plants, enabling pasture breeders to select for high-energy varieties.

The nutritive value of perennial ryegrass is an important driver of productivity for Australia’s red meat and dairy industries, as it contributes towards the total liveweight gain or milk production of grazing cattle.

However, the nutritive value of ryegrass is traditionally not targeted in pasture breeding programs because it is slow and expensive to measure with destructive sampling and laboratory-based low-throughput methods.

Left: Agriculture Victoria Research Scientist Chaya SmithResearch conducted at Agriculture Victoria’s Hamilton research centre is helping to overcome this.

Market report for 11th and 12th December

There was some very good vealers sold to top 315.0 in a yarding of 419 which is an increase of 119 from last week where good cattle sold well.

353 vealers sold to 315.0 cents, averaged 263.6 and per head $932.68, down 1.8 cents from last week.

52 heifers sold to 283.2 cents, averaged 183.1 and per head $617.38, down 56.3 cents from last week.

12 steers sold to 294.2 cents, averaged 243.5 and per head $1297.78, down 12.5 cents from last week.

The yard average for 419 head was 251.6 and $894.12 per head, down 6 cents on last week.

Vealers

1 Lim G&L Bennett, Trafalgar

1 LimX P&H Millar, Poowong

1 B/Blue G&M Fry, Bunyip

1 LimX Koyuga Downs Past, W/G

1 LimX D Oleary, Shady Creek

Heifers

2 Ang

Steers

2 Hfd G&M Fry, Bunyip

1 Ang G&R Scanlon, Drn South

Cows

1X1 PJ Higgins, Hazelwood Sth 1300 Thursday's cow and bull sale. Cow numbers were down slightly on last week and sold very well overall with averages mostly down across the field. Heavier cows were down this week while lighter cows were dearer.

224 cows, 71 less than last week, 43 steers, 53 heifers and 33 bulls with a full field of buyers.

224 cows sold to 260.0 cents, averaged 199.6 and per head $1050.40, up 4.6 cents from last week.

43 steers sold to 250.0 cents, averaged 237.4 and per head $1342.18, down 3.7 cents on last week.

53 heifers sold to 236.2 cents, averaged 220.0 and per head $979.07.

33 bulls sold to 241.2 cents, averaged 2204.6 and per head $1442.79, down 41.2 cents from last week.

Yard average for 354 cattle was 207.8 and per head $1114.63, down 4 cents on last week.

Beef

1 Char D&P Roberts, Yarragon 550 260.0 1430 1 Ang Campbell & Cromwell, Mod. 620 260.0 1612 1 Ang J Omealy, Yarragon 570 244.6 1394 1 Ang Harvest Field, Mt View 680 239.2 1626 5 AngX G&L Nuttall, Warragul 588 238.2 1400 2 R/Ang B Fraser, Warragul 570 238.0 1356 Dairy

2 Frn

2 Frn

2 Frn

1 Frn

2 Frn

Steers

2 Hfd

4 Frn

7 Frn

1 AngX

5 Frn

Heifers

6 FrnX

1 FrnX

Bulls

1 Lim

1 Ang

1 S/H

3 Frn

1 Jsy

Seaview Park, Seaview

ST Dyall, Hill End SR Bransgrove, Neerim L&L Allen, Hallora

C&D Kelliher, Neerim Sth Regano Farms, Ferndale

R Johnson, Longwarry CJ Williamson, Athlone ST Dyall, Hill End

G&R Scanlon, Leongatha Saxton & Waller, Yarragon

F&S Hedrick, Ellinbank B&H Saxton, Yarragon

M&D Reynolds, H/wood 860 241.2 2074 B Sibley, Darnum 985 221.2 2178 DMT Pentland, Trida 815 209.6 1708 Jayanal, Longwarry 347 207.2 1029 M&M Briggs, Drouin 855 200.0 1710

1. SEJ, 2. NGL, 3. Elders, 4.

Scotts, 5. Landmark

335 360 395 390 350

553 283.2

530 294.2 600 255.6 553 683 628 775 637

657 585 564 615 502

532 530

315.0 313.2 312.2 310.0 302.2 239.6 236.6 227.6 226.2 225.2

250.0 245.6 243.6 240.0 234.2

236.2 235.2

1055 1127 1233 1209 1057

1566

1559 1533 1323 1614 1428 1753 1435

1642 1436 1373 1476 1175

1257 1246

In this research, data was collected from ryegrass plants using a field spectrometer – a scientific instrument which can measure substances in plants such as sugars or fibres.

The data collected by the spectrometer was then used to develop prediction models for eight nutritive value parameters such as protein, fibre and digestibility.

Agriculture Victoria Research Scientist Chaya Smith said the new field-based model was very promising for pasture breeding programs and farmers.

“This will provide a way to improve the nutritive value of forage varieties that is much faster and cheaper than anything that currently exists,” she said.

The models also provide a tool for selection in breeding programs with a high degree of accuracy comparable to laboratory-based spectrometry.

“The accuracy varies with each of the eight nutritive value parameters, but protein, dry matter and digestibility were 80 per cent accurate,” Ms Smith said.

“For more complex traits such as fibre content, we are collecting more samples from different environments and growing seasons to make the prediction model more robust.

“We are also developing a machine learning approach to improve the prediction of sugar content, which is complex as grass sugar content changes over the course of the day.”

Australia’s grazing industries will benefit significantly from pastures with better nutritive value.

Ms Smith said improvement in these herbage quality traits would increase the amount of nutrition available for stock and would decrease the need for, and reliance on, costly supplements.

“Eventually, as the model is further developed, it could also be a tool for farmers to check the quality of their pasture in the field, providing relevant, real-time information for decision making,” she said.

The research is part of the DairyBio joint venture between Agriculture Victoria, Dairy Australia and the Gardiner Foundation.