Efficient Beef Production

Transcription

1 Efficient Beef Production a view from the paddock Glenn Judson

2 Introduction Principles of efficient meat production Importance of farm system Factors affecting grazing intake Forages system example Cocksfoot for beef production

3 Fast is Efficient Liveweight gain (kg/day) Feed intake (kg DM/day) Days to target weight ( kg) Total feed consumed (t DM) Feed conversion (kg DM/kg LWG)

4 Fast is Efficient Daily Intake (MJ ME/head/day) Energy for Energy maintenance for maintenance maintenance maintenance 0 Low Intake High Intake

5 The Growth Wheel Pasture quality / quantity Stocking rate Birth date Genetics Rapid liveweight gain Animal Health Management Trace elements Weather & geography

6 Stocking rate Liveweight gain/ha/yr maintenance maintenance Stocking rate (head/ha) Adapted from Clark (1992) 50 Liveweight gain/head/yr

7 Target Growth Path kg/day 0.5 kg/day Liveweight (kg) maintenance maintenance 250

8 Marshdale Beef production

9 15-Oct 3-Apr 17-Apr 1-May 15-May 29-May 12-Jun 26-Jun 10-Jul 24-Jul 7-Aug 21-Aug 4-Sep 18-Sep 2-Oct 16-Oct 30-Oct 13-Nov 27-Nov 11-Dec 25-Dec 8-Jan 22-Jan 5-Feb 19-Feb 5-Mar 19-Mar 2-Apr 16-Apr 30-Apr 14-May 28-May 11-Jun 25-Jun 9-Jul 23-Jul 6-Aug 20-Aug 3-Sep 17-Sep 1-Oct Marshdale Beef production Liveweight gain Series1 All Autumn Winter Spring Summer 2 nd Autumn 2nd Winter Liveweight (kg)

10 Subdivision maintenance maintenance

11 Target Growth Path Liveweightgain Disaster OK to be here After beer! OK to be here Relative Stocking rate

12 Factors Affecting Intake Energy for maintenance maintenance Feed in here Feed quality

13 Grazing Intake Daily grazing intake = bite size x bite rate x grazing time (g/bite) (bites/minute) Hours/day

14 Grazing intake = bite size x bite rate x grazing time Bite size has greatest influence on intake Affected by pasture height (mass) Diet selection / preference

15 Grazing intake = bite size x bite rate x grazing time Bite size and dimensions of yearling cattle grazing pastures of three different heights Pasture height (cm) Bite weight (g fresh) Bite weight (g DM) Depth (cm) Area (cm 2 ) Volume (cm 3 ) Density (mg/cm 3 ) Source: Mursan et al Proc. NZ Society Animal Production

16 Grazing intake = bite size x bite rate x grazing time Pasture availability Pasture species with more leaf DM towards the top of the plant support higher intake because it is more easily harvested Source: Jagusch et al. 1979

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19 Grazing intake = bite size x bite rate x grazing time Bite rate limited to 30000/day Physiological drive increase bite rate Affected by sward structure and mass Affected by diet selection Effect is relatively small

20 Grazing intake = bite size x bite rate x grazing time Forages Bite rate Bite weight Eating rate (bites/min) (g DM/bite) (g DM/min) A B C D E F Source: Dynes et al Proc. NZ society of Animal Production

21 Grazing intake = bite size x bite rate x grazing time Grazing time rarely exceeds 10 hours/day, usually 6-9hrs As availability declines GT increase but intake declines Physiological drive increase GT Grazing fatigue reduces intake when availability is very low

22 Digestibility usable DM Dig % = 10.0 kg Eaten 2.5kg excreted 10 kg eaten Dig % = 75% Steer gets to use0.75 kg Dig % = 10 kg Eaten 4.5 kg excreted 10 kg eaten Dig % = 55% Steer gets to use0.55 kg

23 Rate of clearance from the rumen Fractional degradation rate (/hr) Hrsto Fresh Forage 50 % Perennial ryegrass Kikuyu Paspalum White clover Chicory Plantain Adapted from Burke et al Proc. NZ Soc. An Prod.

24 Evaluation of pasture species

25 DM production Yield (kg DM/ha) May April March February January December November October Sptember Winter Savvy Native Prospect

26 Beef production Forage Grazing days AV. LWG Stocking rate LWG/ha Native Prospect (P. ryegrass) Savvy (Cocksfoot)

27 Summary Fast is efficient Stocking rate critical Bite size drives intake Forage systems

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