Impact of nutrition on carbon emissions (Efficiency, feeding & production system) Dr Jimmy Hyslop Beef Specialist
Environmental Impacts • UK agricultural GHG emissions: expressed as CO 2 equivalents – Carbon dioxide (GWP 1) • Energy use, burning fossil fuels – Methane (GWP 25) • Enteric fermentation, manure management – Nitrous oxide (GWP 296) • Fertilizer, manure management 2 2
EU livestock Greenhouse Gases Mton CO 2 equivalent Enteric fermentation (CH 4 ) 148 Manure handling (CH 4 ) 52 Manure handling (N 2 O) 33 Pasture manure (N 2 O) 26 Total 260 CE Delft, 2008 3
Greenhouse Gas Emissions from UK Agriculture 2007 1990 Other Other 0.46% 1.0% Arable Arable Pigs & Pigs & 19.0% 19.1% Poultry Poultry 6.9% 8.1% Ruminants Ruminants 73.1% 72.4% Total: 43.22 Mt CO 2 e Total: 54.64 Mt CO 2 e Gill, 2012 Source: AEA (2009) and Dairy Co (2009) 4 4
Proportional contribution of livestock species in UK to production & GHGs Species Contribution to Contribution to production GHG emissions Poultry 0.48 0.26 Pigs 0.21 0.16 Cattle 0.22 0.27 Sheep 0.1 0.21 5 5 Gill, 2012
UK Livestock Population % Change 1990 to 2010 Dairy Cows -36 Beef Cows +6 Sheep -29 Pigs -41 Poultry +28 DEFRA statistics 6
Output per Head % Change 1990 to 2010 Milk yield per cow + 42 Prime beef carcase weight + 21 Lamb carcase weight + 7 Pig carcase weight +20 DEFRA statistics 7 7
IPCC Methane inventory (kg/head/year) Enteric Manure Dairy cattle* 100+ 44 Other cattle 48 20 Sheep 8 0.28 Pigs 1.5 10 Poultry N/A 0.117 * Based on 4,200 kg milk/yr. Actual figure used is calculated from NE intake as 6.5% of GE 8
Origin of Methane Grass Cereals (cellulose) (starch) Pyruvate Pyruvate Archaea H 2 Archaea CO 2 Methane Acetate Propionate 9 9
Strategies to reduce GHG • Individual animal – Improve milk yield or LWG (↓ maintenance, time to finish) – Improve FCE (↓ carbon emissions/kg DMI, ↓ excretion) – Change diet (↓ carbon emissions/kg DMI , methane and excretion) • System level – Reduce animal wastage (e.g. lose fewer replacement heifers) – Better fertility and health (spread emissions over more output) – Improve longevity (less emissions for replacements) 10 10
Strategies to reduce GHG • Modify rumen fermentation – More concentrates, less forage so less methane – Increase dietary oil content (reduces fibre fermentation) – Additives (silver bullets) – nitrate seems to be current favourite • Manure management – Reduce CP content of diet - (yes but watch productivity) – Slurry management - (store so can spread at right time) – Slurry application - (injection = good: splash plates = bad) 11 11
CH 4 500 L Urine/Faeces (69%) N 340 g Feed Milk DM 18 kg Yield 30 kg N 490 g Daily Input & N 150 g Output for an Average Cow 12 12
Methane and Milk Yield 250 cows 100 cows 1 million litres 60 50 Methane (t/yr) 40 6.5% GE 30 20 Diet adjusted 10 0 4000 5000 6000 7000 8000 9000 10000 Milk yield (l/cow/yr) 13 13 Garnsworthy (2004)
Predicted Methane Emissions • Rowett feed factors (ME system) – ME determination includes CH 4 measurement • Animal equation - Total daily Methane production is related to Dry Matter Intake Positive Proportion of concentrates in diet Negative Fibre content of diet Positive CH 4 (MJ/d) = 1.36 + 1.21 DMI – 0.825 DMconc + 12.8 NDF (Yates et al. , 2000) 14 14
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Effect of low and high methane diets on CH 4 Methane Diet Low High sed P . Dry matter intake (kg/d) 23.6 20.3 0.31 <0.001 Milk yield (kg/d) 32.7 32.1 0.28 0.034 Methane emission rate (g/d) 373 395 8.2 0.042 (g/kg DMI) 15.8 19.5 0.58 <0.001 42 cows, 14 days per diet, crossover design Diets: Low = commercial TMR (maize, grass & whole-crop silages; SBP, rape, soya, fat, M&V) High = Low + double grass silage (13% -> 30%) + peas (2kg/d) 16 16
Replacement numbers 1984-2007 3 500 35 Number of Animals (000) 3 000 Dairy cows Replacement rate (%) 2 500 30 2 000 Replacement rate 1 500 25 3 lactations 1 000 Heifers in calf 500 0 20 4 lactations 1980 1985 1990 1995 2000 2005 Year Defra Statistics 17 17
Dairy production - Conclusions • Production efficiency (number of animals) is the main driver of total emissions and excretions • Feed intake is the main determinant of GHG per animal • Feed efficiency affects product per unit pollution • Methane and nitrogen can be manipulated by nutrition – both directly and indirectly 18 18
Efficiency of production and climate change Beef production systems 19
Efficiency & carbon emissions in beef production What is it all about ? Better conversion of feed into meat (FCR) Net Feed Efficiency (RFI) Lower Greenhouse Gas Emissions (Carbon Footprint) Also More calves / 100 cows mated (fertility) Improved animal health (more calves to sell) More output / £ spent on fixed costs (More profit & lower environmental impact / kg beef) 20 20 20
Hill Suckler Herds 21 21 21
Nutrition, feeding, efficiency & emissions in beef systems 22 22 22
Efficiency & carbon emissions in beef production Nutrition, efficiency, systems & carbon emissions Measure main inputs (feed intake) Quantify beef outputs (LWG, carcass wt etc) Measure CH 4 & N 2 O etc (Carbon Footprint) (More profit & lower environmental impact / kg beef) 23 23 23
Implications for beef systems - EFFICIENCY IS KEY Waste / Pollution e.g. GHG & NH 3 Inputs Processes Outputs Feed Cellular Fixed costs Tissue (rumen) Supply for human needs/wants Animal e.g. Beef System • The way to reduce Global warming in practice is to improve the efficiency of the processes that we use to turn raw inputs into a 24 24 supply of human needs/wants 24
Results Factors affecting methane production/day Concentrate Forage:Concentrate Methane produced g/day 142 205 *** (l/day) (237) (342) Methane Yield g/kg DMI 13.7 21.5 *** (35.8) (l/kg DMI) (22.8) 25 25 25 25 25
Results Factors affecting methane production/day Breed effects ? – Little effect seen between AAx & LIMx when scaled to DMI or LWG (now looking at CHx & Luings) BUT:- CH 4 output between sires within AA & LIM breeds (g/day) (g/kg LWG) 250 205 200 176 170 157 191 189 172 Methane/ADG (g/kg*d) 180 169 170 200 136 147 151 137 130 160 122 136 132 Methane (g/d) 117 140 150 120 100 100 80 60 50 40 20 0 0 AA1 AA2 AA3 AA4 AA5 LIM1 LIM2 LIM3 LIM4 AA1 AA2 AA3 AA4 AA5 LIM1 LIM2 LIM3 LIM4 Sire Sire Scope for selection within breeds ????? 26 26 26 26 26
Dry suckler cows (no sig breed effects) Straw/Silage Straw/BG LIMx Luing LIMx Luing sed Diet DMI (kg/d) 9.9 9.8 9.2 9.4 0.89 NS CH 4 (g/d) 140 161 125 129 18.3 *** (g/kg DMI) 14.6 15.8 14.2 13.5 2.21 NS % of GEI 4.34 4.70 4.10 3.89 0.65 * (4.52) (4.00) (12% less) 27 27 27
Key Messages • Wide range in methane outputs - differences between animals – scope for genetic selection • Confirms what we already know – less methane per kg gain in high concentrate & high oil diets • Within any system, the more efficient the animals are, the less methane / kg gain • What about choice of system ? 28 28 28
Results - CO 2 Eq. / CCW sales from 100 cow suckler herd (tonnes CO 2 Eq. / tonne CCW sold) Figure 5. Relative GWP contributions (t CO 2 eq. / t CCW) from the suckler breeding herd, heifer replacements and finishing cattle system (H x FS) 24 Suckler herd Replacements Finishing system 20 Total CO 2 eq. (t/t CCW) Dx PB RO CO SS 16 12 8 4 0 12 18 24 30 12 18 24 30 12 18 24 30 12 18 24 30 12 18 24 30 Finishing system (months) • Without changing the efficiency of the individual animal through breeding: – Greatest scope for reducing GHG in beef systems is to shorten the finishing system – Has major implications for the nutrition / feeding of these animals 29 29 29
NFE results – 1 st batch of bulls Net Feed Efficiency (82 Stabiliser Bulls) Low NFE Mid NFE High NFE 2.00 1.50 NB: @ feed cost of £155/t DM - 12 weeks on Wold farm NFE test 1.00 NFE (kg/d) 0.50 0.00 -0.50 -1.00 Low NFE Average High NFE -1.50 -2.00 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 Bull Mean LW (kg) 567 574 582 DLWG (kg/d) 1.9 1.9 1.9 Fat depth (mm) 6.0 6.4 6.2 DMI (kg/d) 12.0 12.9 13.8 FCR (DMI:LWG) 6.5 7.1 7.5 NFE (kg/d) -0.75 0.0 +0.76 Cost deviation from average - £11 0 + £12 Methane (l/day) 436 467 499 30 30 30
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