Environmental impact of animal production
Perugia, June 16th, 2017 – 22nd Congress of A.S.P.A.
G. Matteo Crovetto e Stefania Colombini
Luca Malagutti(Ω June 9, 2017)
World human growth
1960: 3.5 billion people; today: 7; in 2050: >9.
Today 50% of world people live in cities; in 2030 60%; in 2050 ??
A laid table for all the people of the world would be 2.8 million km long (7.5 times the distance Earth-Moon): quite a problem to feed everyone! (Pulina, 2011)
To produce food, crop and livestock systems need soil and water, both limited and diminishing resources.
G.M. Crovetto, Perugia 16-6-2017
World rural and urban population (1960-2050) (FAO, 2013)
Mission of agriculture and livestock systems
1° Supply food.
2° Preserve the environment.
For thousands of years man cultivates fields and rears animals for food.
Livestock systems: transform vegetable protein and fibre into animal protein of high nutritional value.
Animal kingdom: no fibre food of very high digestibility.
Food of animal origin: high nutritive value.
G.M. Crovetto, Perugia 16-6-2017
Meat, fish, eggs, milk and cheese supply man with essential nutrients hard to get from only vegetable-based diets. Among these:
essential amino acids (lysine, methionine, threonine, tryptophan, leucine, isoleucine, phenylalanine, histidine and valine)
essential fatty acids (e.g. ω3 and CLA)
minerals (e.g. Ca, P, Mg) and vitamins (e.g. B12)
Assets of food of animal origin
Contribute (%) of food of animal origin to human diet
16
37
56
2529
12
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Available protein and animal protein supply in the period 1990-2009 (FAO, 2013)
Which type of crop and animal production systems?
Basically 3 main systems:
Extensive (normally small-scale, family farming)
Semi-intensive (medium scale, group farming)
Intensive (large-scale, industrial farming)
Extensive systems rely on pasture (for ruminants) andscavenging and kitchen waste for monogastrics. Crop by-products
can be fed both to ruminants and monogastrics.
Intensive systems have high stocking rates and supply feeds heavily
or totally risk for the environment.
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Strengths and weaknesses of animal production systems
Extensive systems: very low costs and normally low levels ofproduction. 1-2 billion people rely on these systems for theirfood supply.
Intensive systems: high inputs and costs, and highproduction levels. The majority of the world populationdepends on these food supply systems. However: risk of
negative environmental impact.
Efficiency must be improved in both systems to attaineconomic and environmental sustainability.
Environmental impact should be assessed per kg product(meat, milk, eggs, fish) more than in absolute values.
G.M. Crovetto, Perugia 16-6-2017
Which are the most efficient animals?
100 kg feed (madeby 80% cereal grainand 20% proteinsuppl.) can produceabout:
45 kg chicken
meat
35 kg pork
15 kg beef
0
5
10
15
20
25
30
35
40
45
chicken pork beef
45
35
15
For fibre: ruminants (cattle, sheep and goats, buffaloes, camels).
For starchy feeds: monogastrics (pigs and poultry).
kg meat from 100 kg feed
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Maintenance, a fixed cost to be amortized
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Factors involved in the process of sustainable ruminant
production to feed the planet (Pulina et al., 2017)
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The environmental sustainability of food production
depends also on the types of human diet
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Mean dietary GHGEs per 2000 kcal for high meat-eaters (>100 g/d; n=8286), medium meat-eaters
(50–99 g/d; n=11971), low meat-eaters (>0 and<50 g/d; n=9332), fish-eaters (n=8123),
vegetarians (n=15751), and vegans (n=2041) in the United Kingdom (Perignon et al., 2017)
Types of diets and human health
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Prudent diets with plenty of fruits, vegetables, nuts, legumes, and unrefined cereals and adequate amounts of meat, fish, and dairy products have also demonstrated beneficial effects on health (WHO-FAO, 2003).
In addition, avoiding animal products does not necessarily provide health benefits (Key et al., 2006).
Animal products are sole providers of some essentials nutrients, so that restrictive and monotonous plant-based diets may result in nutrient deficiencies with deleterious effects on health (Millward and Garnett, 2010).
Types of diets and human health (cont.)
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The harmful impact of animal-based products on human health is only documented for processed and red meat at intakes higher than 50 and 100 g/d, respectively (IARC, 2015).
Moreover, the higher rate of mortality and chronic disease associated with Western diets is due not only to a high content of red and processed meat but also to excessive consumption of refined cereals, fried foods, soft drinks, sweets, and energy-dense, nutrient-poor food products.
IARC= International Agency for Reseach on Cancer
Effect of five diets on GHG emissions (Tilman and Clark, 2014)
Protein conversion ratios of livestock production systems (Tilman and Clark, 2014)
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Global warming potential for livestock products, in CO2eq
expressed per kg of product (de Vries and de Boer, 2009)
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Contribute (%) of different species to global CO2
equivalents emissions from livestock (FAO 2013)
41
20
98 8 6
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Global emission of CO2 equivalents per kg of protein from different sources (FAO 2013)
From poultry and pigs less GHG/kg protein than from ruminants
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Biomass use efficiencies for the production of edible protein from beef and milk for different production systems and regions
of the world.(Herrero et al., 2013. From IPCC 2014)
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GHG emissions intensities of selected major agriculture, forestry and other land use commodities for decades 1960s – 2000s.
As agricultural and silvicultural efficiency have improved over recentdecades, emissions intensities have declined.
Whilst emissions intensity has increased (1960s to 2000s) by 45% for cereals,emissions intensities have decreased by 38% for milk, 50% for rice, 45% forpig meat, 76% for chicken, and 57% for eggs.
(FAOSTAT 2013, from IPCC 2014)kg CO2eq/kg or m3 product
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Productivity and emission intensity
A large potential to mitigate emissions exists in low-yield ruminant production systems.
Improved productivity at the animal and herd level can lead to a reduction of emission intensities while at the same time increasing milk output.
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Environmental impacts (%) per unit of product of concentrate-based
relative to roughage-based beef production systems (de Vries et al., 2015)
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GWP=global warming potential; AP=acidification potential; EP=eutrophication potential.
Carbon footprint of conventional and organic beef production
systems: an Italian case study (Buratti et al., 2017)
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CONVENTIONAL and ORGANIC=18.2 and 24,6 kg CO2eq/kg LW, respectively
In ORG farm, the longer
finishing period and type
of diet caused the
higher enteric
fermentation and manure
management emissions,
despite
the advantage of the
absence of synthetic
fertilizing that allows a
low impact for feed
production.
Environmental impacts of Italian beef production: a comparison
between different systems (Bragaglio et al., 2017)
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CCI= Cow-Calf Intensive (cow-calf operations, with specialized beef animals constantly kept
in confinement)
FS= Fattening Systems (high grain fattening of specialized beef breed imported calves)
PoS= Podolian system (cow–calf operations, with Podolian cattle maintained on pasture and
finished in confinement.
SE= Specialized Extensive (specialized beef cattle maintained on pasture and finished in
confinement)
Functional unit: 1 kg of live weight of marketed beef cattle.
Environmental impacts of Italian beef production: a comparison
between different systems (Bragaglio et al., 2017)
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GWP of light and heavy pig production from LCA studies(adapted from Bava et al., 2017)
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3,10
4,26
GWP of heavy pig production from LCA studies: contributions of
different activities to environmental impact categories (Bava et al., 2017)
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Daily nitrogen (N) balance of pigs at 152 kg BW (Galassi et al., 2010)
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C=control; HF=high fibre; HFLP=high fibre-low protein.
Protein content (g/kg as-fed basis): C 120, HF 122, HFLP 98
Effects of dietary protein and essential amino acid content
on N balance in pigs of 129 kg BW (Galassi et al., 2015)
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CONV=conventional diet; LP1=low protein and low essential amino acids diet; LP2=low
protein and conventional essential amino acids diet.
CP and Lys (g/kg as-fed basis): CONV: 132-5.5; LP1: 104-4.3; LP2: 97-5.1
Energy yield from forage systems in Lombardy (Zucali et al.,
2014)
Cornsilage It. ryegrass Corn grain High moisture HM ear Perm. mead. Lucerne
silage + CS dried shelled corn corn hay hay
MJ
NE
l/h
a
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GHG and forage systems in Lombardy (Zucali et al., 2014)
Cornsilage It. ryegrass + CS Corn grain dried High moisture corn HM ear corn Perman. meadow hay Lucerne hay
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Forage systems for milk production in the Po plain
Base forage: mainly corn silage high DM and NE yield,
but also high economical and environmental costs (water,
GHG, fertilizers, pesticides, …) and need to purchase
protein supplement (e.g. soybean meal LUC, GHG, …
(Battini et al., 2016)
Nowadays there is more attention to permanent meadows
for their very low cost and their ability to improve C sink
in the soil.
Replanting grasses in lands previously sown with annual
crops can result in a significant increase in soil C, and in
some cases the soil C gain more than offset all the GHG
emissions from the farming system (Guyader et al., 2016).
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LIFE Project “FORAGE4CLIMATE”
LIFE4CLIMATE aims to demonstrate that the forage systems connected to milk production (dairy cattle and small ruminants) can contribute to climate change mitigation in terms of:
Reduction of GHG emissions per kg milk
Increase of soil carbon stocks
through:
Proper choice of forage system
Adoption of Good Practices
Use of simple tools for the evaluation of C stocks and GHG emissions
Forage systems for less GHG emission and more soil carbon sink in continental and mediterraneanagricultural areas
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Milk productivity and emission intensity (FAO 2013)
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Nitrogen in milk and protein content of the diet
Dietary Crude Protein (% on DM)
Mil
k N
/in
tak
e N
(%
)
(Crovetto and Colombini, 2010)
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Nitrogen in milk and dairy efficiency
Dairy efficiency (kg milk/kg DM intake)
Mil
k N
/in
tak
e N
(%
)
(Crovetto and Colombini, 2010)
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Methane production and dry matter, starch and NDF intakesin lactating cows (Colombini et al. 2015)
Higher CH4 emission with NDF than with starch.
Starch
NDF DM
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Methane emission per kg DM intake and milk yield
Pirondini et al., 2015.J. Dairy Sci. 98: 357–372
Open circuit respiration chamber
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High yielding dairy cows produce less methane/kg milk
40 kg milk/d 20 kg milk/d 20 kg milk/d
148 kg methane/year
(11,7 g CH4/kg milk)
234 kg methane/year (+58%)
(18,6 g CH4/kg milk)
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Less N to the soil and /kg milk from high yielding cows
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40 kg milk/day 20 kg milk/day 20 kg milk/day
99 kg N to soil/year
(7,8 g N to soil/kg milk)
157 kg N to soil/year (+59%)
(12,7 g N to soil/kg milk)
Cradle-to-farm-gate emissions of 45 typical farms(Hagemann et al., 2011)
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Total environmental impacts per kg of FPCM for 28 Italian dairy farms and on-farm contributions (Bava et al., 2014)
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Numbers of studies showing positive, negative or mixed/no difference when
species abundance and/or richness where compared in organic versus conventional farming (Tuomisto et al., 2012)
The key challenges in conventional farming are to improve soil quality (by
versatile crop rotations and additions of organic material), recycle nutrients and
enhance and protect biodiversity.
In organic farming, the main challenges are to improve the nutrient management
and increase yields.
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Also non-milk producing animals contribute to GHG emissions
A balanced breeding strategy optimizing milk production capacity
while minimizing the number of non-milk producing cattle is
important with regard to minimizing emissions from dairy
production systems.
For example Weiske et al. (2006) found that a reduction of 10% in
replacement rate, combined with a strategy to sell surplus heifers
at birth, reduced total emissions by 10%.
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Relative distribution of wasted mass and wastage CF for five supermarket departments studied (Scholz et al., 2015)
Over a three-year period, 1570 t of fresh food (excluding bread) were wasted in the
supermarkets. The associated total wastage CF was 2500 t CO2eq.
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Share of wastage carbon footprint (CF) and wasted mass of the meat total waste (BF = bone-free) (Scholz et al., 2015)
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Conclusions
Protein of animal origin can positively integrate a vegetable-based
human diet.
Natural meadows and pastures are to be utilized through ruminants
protein from fibre. No other use of these lands.
Extensive and family farming systems must be maintained (human
presence, land protection, less urbanization), but their efficiency must
be improved.
Semi-intensive and intensive livestock production systems are
essential for food supply and should not be demonized, but must
minimize the environmental impact through genetics,
nutrition&feeding, and management.