Tools for managing g pasture

Transcription

1 Tools for managing g pasture John Roche Principal Scientist, Animal Science Managing Director, Down to Earth Advice Ltd.

2 Room service for Stacey Hamilton

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11 Objective: To grow and utilise as much pasture as possible

12 Pasture Utilised & Operating profit ng profit t, US$/ac y = 289.9x R² = 0.60 Operati Ton/ac utilised

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14 Grazing Residual and Intake % increase in intake Cow Intak ke lb DM/ /cow 50% increase in residual Post Grazing Residual lb DM/ha

15 There is no greater force than the control of stocking rate in Grassland Farming -C.P. McMeekan (c1950)

16 Pasture grown/uti ilised, kg DM/ha 25,000 20,000 15,000 y = 985.6x R² = 0.64 For every 0.5 cows/acre you grow an additional 1,100lb DM/ac y = 2073x R² = , Stocking rate, cows/ha

17 Pasture grown/uti ilised, kg DM/ha 25,000 20,000 15,000 y = 985.6x R² = 0.64 For every 0.5 cows/acre you utilise an additional 2,300lb DM/ac y = 2073x R² = , Stocking rate, cows/ha

18 Do you know Your adjusted acreage Your milking platform acreage Optimum SR = 180 lb Lwt/ton total feed (pasture +supp) 6 ton DM/ac, 1100 lb cow, 1,000 lb purchased supplement/ac Optimum SR = 1.1 cows/ac Do you know what each paddock produces/yr 100% difference between your best and worst paddock If you don t measure, you can t manage

19 Managing pasture is as easy as 1, 2, 3

20 Energy allocation Animals Maintenance Production - milk -growth - reproduction Body condition score

21 Energy allocation Animals Maintenance Production Plants Maintenance (respiration) Production - milk - leaves -growth -roots - reproduction - tillers Body condition score Storage

22 How pasture grows Pas sture yie eld, kg DM M/ha Days post-grazing

23 How pasture grows Pas sture yie eld, kg DM M/ha Days post-grazing

24 How pasture grows Delay grazing Pas sture yie eld, kg DM M/ha % 26% 65% Leaf 1 Leaf 2 Leaf 3 Leaf Days post-grazing

25 Canopy closure

26 Canopy closure When you can t see the ground or pasture base directly below (usually > 2,500 lb DM/ac) If > 25% of paddock is affected: Poor quality pasture Decline in tillering Post-grazing residuals will increase

27 What about Quality? NDF (%DM M) Number of leaves/tiller

28 The sweet spot maximising gpasture grown and quality Pas sture yie eld, kg DM M/ha Days post-grazing

29 How tight should we graze?

30 How hard to graze 1.5 inches

31 How hard to graze 1.5 inches 3 inches 3 inches (following 2 to 3 rotations) ti

32 How hard to graze 0.75 inches (following 2 to 3 rotations) 0.75 inches 1.5 inches 3 inches 3 inches (following 2 to 3 rotations)

33 Phenotypic plasticity 2 inches residual 1 inch residual

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36 Spring Grazing Trial Ruakura 1992 Grazing Residual at Start of 52 day Grazing Interval Cover after 52 day grazing Interval September Accumulated Growth Kg DM/ha/day /d (52 days) Average growth rate Kg DM/ha/day lb DM/ac

37 How hard to graze pasture Ideal height is ~ 1.5 to 2.0 inches (equates to ~ 7 8 clicks on rising platemeter) Irrespective of (cool season) pasture species NEED to get it right early!

38 What about the cows Set pastures up at 1.5, 2.0 and 2.5 inches Cows then grazed to previous height Milk yield not different at 1.5 or 2.0 inches Milk yield reduced at 2.5 inches

39 Impact of grazing Residues on Pasture ME 6 Canterbury Monitor Dairy farms 2003 season ME Target residual 7 "clicks" 11.5 High residual "clicks" June Aug Oct Dec Feb Apr June

40 To summarise grazing management Graze when more than 2 leaves on >75% tillers Graze prior to canopy closure Exception during late fall with dry cows Graze to 1.5 inches Must begin as you intend to continue

41 Tools to enable efficient management Anything that allows you to estimate pregrazing mass, leaf stage, and post-grazing height Plate meter, C-Dax, eye-ometer Rotation planner/wedge

42 Spring Rotation Planner Rotation Length Round le ength (day ys) Point A 26th August graze 1/60 th of the farm = 2 ac ha/day for a 120 ac ha farm Point B 10 1-Aug 6-Aug 11- Aug 16- Aug 21- Aug 26- Aug 31- Aug 5-Sep 10- Sep Rotation Sep 20- Sep 25- Sep 30- Sep

43 Rotation Length After Calving Target Cover Low Cover, Fast Rotation Low Cover, Slow Rotation Cover Pasture Jan Jul Aug Feb Sept Mar Oct Apr Nov May Dec June Jan July Aug Feb

44 It requires flexibility and adaption

45 It requires flexibility and adaption Feb 15 th Mar 31 st Apr 15 th Silage Silage Silage

46 Tools Plate meter, C-Dax, etc. Rotation planning, grazing wedges, etc. Your eyes and your brain

47 Phew. Thank God Willy John s not here to graze