Team 7 Report - Ministry of Forests, Lands and Natural Resource ...

Team 7 

Evaluating the environmental impact of the British Columbia 

cattle ranching industry in the Lac du Bois Grasslands. 

THOMPSON RIVERS UNIVERSITY, KAMLOOPS, BC 

Submitted by 

Allan F. Raymond and John S. Church 

November 30, 2011 

Page 1 of 17


INTRODUCTION 

Methane (CH 4 ) is a greenhouse gas (GHG) whose atmospheric concentrations have increased 

dramatically over the last century. The rising concentration of CH 4 is strongly correlated with increasing 

populations, and currently about 70% of its production arises from anthropogenic sources (Moss, 2000) 

(IPCC, 2007). Methane released to the atmosphere by domestic ruminant livestock is considered to be 

one of the three largest anthropogenic sources (Steinfeld, 2007). Globally, ruminant livestock emit 

roughly 80Tg (1 Tg = 10 12 g = 1 million metric ton) of methane annually, accounting for about 20-25% 

percent of the global anthropogenic CH 4 emissions, and roughly 12% of the total atmospheric CH 4 load 

(Gagen, 2007). Methane is considered by many to be one of the largest potential contributors to climate 

change (Stejian, 2010). Methane is a concern for livestock production because it is generated by 

ruminant animals in large quantities during the normal process of feed digestion (Beauchemin, 2009). In 

a life cycle assessment (LCA) of beef production in Western Canada, Beauchemin et al. (2010) 

determined that enteric CH 4 was the largest contributing source of GHG from the beef industry, 

contributing 63% to total emissions. They further determined that the cow/calf sector accounted for 

approximately 80% of total industry emissions, with 84% of enteric CH 4 coming from mature cows. Many 

governments have implemented strategies and policies to reduce greenhouse gas emissions from 

agriculture, and significant efforts are being directed towards developing animal husbandry methods 

that lower enteric methane emissions (Beauchemin, 2007). In addition to GHG issues, methane 

emissions from cattle represent a carbon loss pathway that results in reduced productivity. If the energy 

that is lost in generating methane could contribute to weight gain, it would be cost effective to the 

producer. Past studies have shown that methane production is dependent on the quality and quantity of 

the diet (Beauchemin, 2007). Generally highly digestible feeds yield lower methane emissions when 

compared to poorer quality diets. Dietary manipulation may provide a mechanism for reducing methane 

emissions from domestic livestock. 

The ranching industry and beef production has a long and storied history both in Canada and 

specifically in British Columbia. In much of rural B.C. ranching is a mainstay of local economies. Most 

beef ranches in B.C. are cow/calf, or cow/yearling operations. There were 4,086 cattle ranches in B.C. as 

reported in the 2006 agricultural census. Revenue from cattle sales in 2008 was $250 million. The B.C. 

beef herd was approximately 212,000 cows in 2009, which represents 4.5% of Canada’s herd. Alberta is 

the largest producer of beef in Canada, with 45% of the national herd (Government of British Columbia, 

2009). 



Not unlike other sectors in B.C. during these recessionary times, the cattle sector has 

experienced financial distress. At the same time, the cattle industry in B.C. remains optimistic that world 

demand for beef is increasing. Forecasters are predicting that North American demand for beef will 

level off, and growth will be focussed upon export markets. A portion of the B.C. sector may also turn its 

attention to local markets and finish more cattle to take advantage of opportunities for value-added B.C. 

beef products. As producers explore opportunities such as “grass-fed” branding to diversify and create 

additional value for their product, the grasslands and grazing areas in B.C. become an ever increasingly 

important component of the production system. As ranchers endeavour to develop these brands based 

on a healthier, environmentally friendly platform, it will be important for them to understand the 

environmental impact of their product, and the environmental consequences of certain management 

practices. 

The purpose of this study was to assist producers to: 1) accurately assess greenhouse gas 

emissions from cattle grazing on crown range land in the central interior of British Columbia., and 2) 

incorporate this information into a whole system modelling approach, or life cycle assessment (LCA) to 

determine the carbon footprint of the cattle ranching industry of British Columbia. 

A measurement technique that makes use of an inert tracer gas (SF 6 ) was been developed that 

allows methane production from individual grazing ruminants to be measured by placing a calibrated 

source of SF 6 (a permeation tube) in the rumen and determining the ratio of methane to SF 6 in the 

animals breath (Ulyatt, 1999). This technique provided estimates of methane production that are 

comparable with those determined by respiration calorimetry in actual grazing conditions, avoiding the 

limitations of other controlled measurement techniques. 

In addition, a life cycle assessment (LCA) model was constructed to estimate the GHG emissions 

associated with a cow/calf production system that utilizes the grazing system predominant in B.C. 

ranching. The emissions were determined using “Holos”, a whole-farm modelling LCA package 

developed by Agriculture and Agri-Food Canada. At present, mathematical models are used to estimate 

CH 4 emissions from enteric fermentation at a national and global level. The Intergovernmental Panel on 

Climate Change publishes guidelines (IPCC, 2006) that are used for official estimates of CH 4 emissions. 

However, the accuracy of these models have been widely challenged (Kebreab, 2006). The actual 

emissions measurements collected in this study helped to validate the accuracy and reliability of the 

model results obtained in this study. 



OBJECTIVES 

This study was comprised of two distinct, yet inter-related components: 

1. Methane measurements using the SF 6 tracer technique from cattle grazing the grasslands of the 

central interior of British Columbia. 

2. A thorough accounting of the environmental impacts of the ranching industry in the grasslands 

of the central interior of BC through life cycle assessment modeling. 

METHODS 

METHANE MEASURMENTS 

The SF 6 calibrated tracer technique in ruminants was pioneered at Washington State University 

by Johnson et al (1994). Various improvements have subsequently taken place, and the current version 

that we utilized is a modification developed by the Dept. of Animal Science, University of Manitoba 

(McGinn, 2006) and from Ag Research Limited, N.Z (Pinares-Patino, 2007a). 

In the sulphur hexafluoride (SF 6 ) tracer technique method, a small, calibrated permeation tube 

containing SF 6 gas was inserted into the rumen of the cattle. A halter fitted with a capillary tube was 

placed on the animals head and was connected to an evacuated sampling canister (PVC yoke). As the 

vacuum in the sampling canister slowly dissipates, a sample of the air around the mouth and nostril of 

the animal was collected at a constant rate over a 24 hour period. After collecting a daily sample, the 

yoke is removed, pressurized with nitrogen, and then the methane and SF 6 concentrations were 

determined by gas chromatography. Methane emission rate was calculated as the product of the 

permeation tube emission rate and the ratio of CH 4 to SF 6 concentration in the sample. 

This technique of capturing enteric methane eliminates the necessity of restraining the animal in 

a chamber. By measuring methane output from a grazing animal we are able to associate the methane 

emissions directly with the animal’s diet while on the native grasslands. 

Since the majority (98%) of the methane is eructated and respired in ruminant animals (Pinares- 

Patino, 2007), collection around the mouth and nose resultd in an accurate estimation of the methane 

production by the animal for inventory purposes. Most hindgut methane is absorbed into the 

bloodstream and respired, so the SF 6 technique will capture most of it as well. 



During the original development of the SF 6 procedure certain key assumptions were examined, and 

for the technique to be reliable in measuring CH 4 it had to meet several criteria: 

1. The release rate of the permeation tube must be constant and predictable. 

2. The tracer must have no impact on ruminal fermentation. 

3. The tracer must be detectable in low concentrations. 

4. The tracer must be inert and non-toxic. 

All of these variables have been satisfactorily addressed by other research groups (Boadi, 2002) 

(Johnson, 2007) (Pinares-Patino, 2007a). To prove the validity of the tracer technique, a series of studies 

have been conducted comparing the measurements of methane production from the SF 6 technique to 

measurements made using indirect open-circuit respiration calorimetry. After 55 measurements using 

the tracer method and 25 chamber measurements, no significant difference in could be detected 

between the two methods. The tracer technique resulted in estimates of 11.53 +0.41 L/h, while the 

chamber measurements averaged 12.36 + 0.33 L/h (Johnson, 2007). 

MATERIALS 

PERMEATION TUBE 

The permeation tube body is constructed from a brass rod, drilled out in the centre to provide a 

cavity for the SF 6 . The open end is threaded to allow the attachment of a Swaglock nut. A thin Teflon 

window, and a stainless steel frit are placed between two Teflon washers and assembled between the 

brass body and nut. The thickness and type of Teflon window dictates the permeation rate. TFE Teflon of 

12mm thickness and a 2 micron frit provide SF 6 permeation rates in the range of 1,000-2,000 ng/min at 

39 o C. The purpose of the frit is to stabilize and protect the Teflon membrane. Weight of the assembled 

tube is taken and an identification number is stamped onto the tube. 

To charge the tube with pure SF 6 , the tube body is immersed into liquid nitrogen. After the tube 

has reached the cryogen temperature, it is removed and any liquid is poured out of the cavity. The 

cavity is then filled with pure SF 6 . This is accomplished by injecting the gas into the permeation tube 

body with a syringe. Once completed, the cap assembly is quickly installed, and the entire device is 

weighed. This procedure provides a tube containing about 600 mg of SF 6 . The tube is then placed in a 

glass receptacle in a 39 o C water bath. A small flow of clean N 2 gas is maintained to purge the glass 

receptacle of any SF 6 emissions. Weights of the tubes are taken weekly to determine the release rate of 

the SF 6 . 



Figure 1: Permeation tube and components used in the study ( photo courtesy of study collaborator 

Alan Iwaasa, 2005). 

HALTER CONSTRUCTION 

The sampling apparatus consists of the collection canister (PVC yoke) and a modified halter. A 

snug, proper fitting halter was critical, as the position of the inlet over the nostril needed to be 

maintained to ensure sampling success. Halters with an adjustable chin strap were utilized, and 

additional holes were installed to ensure a snug fit to the noseband. A leather flap was riveted onto the 

halter noseband to provide support for the capillary tube inlet and filter. 

Figure 2: Modified Halter assembly (Raymond, 2010) 

CAPILLARY TUBING 



The length of the capillary tubing regulates the sampling rate. Stainless steel tubing with an 

inside diameter of 0.127 mm and an outside diameter of 1.59 mm serve as the flow restrictor and 

transfer line. Capillary system is designed to deliver about half the volume contained in the yoke during 

a normal 24 hour collection period. Filling to ½ atm ensures the fill rate will be constant. A 50 micron 

filter system will need to be installed on the upstream (nose) end of the capillary tube to protect it from 

filling with foreign material. The filter assembly will be attached to the leather noseband so the filter 

and inlet tubing are located above the nostril of the animal. The stainless steel calibration tubing is 

located within a PVC tube for protection purposes. On the downstream end of the protective tube, the 

capillary tubing is connected to a length of 3.17 mm PTFE tubing, and a male quick-connect installed on 

the end for connection to the yoke. 

Figure 3: Stainless Steel capillary tubing housed in PVC tube for protection (Raymond 2010, Iwaasa et al, 

2005) 

The sampling apparatus consists of a PVC canister that is designed to fit around a cow’s neck, and then 

attached to the modified halter with approximately 40 cm long electrical tie straps. 

Figure 4: PVC canister placed around the cows neck (Raymond 2010, Iwaasa et al, 2005) 



Figure 5: Schematic – SPARC PVC Methane collection apparatus (yoke) (Iwaasa et al, 2005) 

DILUTION SYSTEM AND VACUUM PUMP 

A vacuum pump was required to evacuate the canisters, a pressure gauge was utilized to 

measure the pressure after filling with a gas sample, and a dilution system was necessary to pressurize 

the sample with nitrogen gas. All items were fitted with a quick-connect system to facilitate use. 



Prior to sampling, a collection canister was evacuated, and the pressure recorded. After the 

sampling period, the pressure was again recorded to validate the sampling was satisfactory. The canister 

was then connected to the dilution system, and nitrogen was slowly added until the pressure in the 

canister increased to about 1.5 atm. The exact pressure is recorded to calculate the dilution factor. A 

sample is then drawn out of the canister with a syringe. Subsequently analysis by gas chromatography 

reveals the methane concentration in the sampling canister. 

Figure 6: Each yoke is over-pressured with pure nitrogen to about 1.5 atm. After 1 hour a sub sample is 

taken (30 ml) to be analyzed by gas chromatography. 

GAS ANALYSIS 

The tracer method utilizes SF 6 to account for dilution as gasses exiting the cow’s mouth mixed 

with ambient air. It is assumed that the SF 6 emission exactly simulates the CH 4 emission; thus the 

dilution rates for SF 6 and CH 4 are identical. 

Determination of the SF 6 and CH 4 mixing ratio (μmol mol -1 ) in the yoke canisters (C sf6 and C ch4 , 

respectively) is needed, and the pre-determined SF 6 release rate (Q sf6 in g d -1 ) are used to determine the 

CH 4 emission (Q ch4 in g d -1 ) (refer to Equation 1). Background SF 6 and CH 4 mixing ratios (CB sf6 and CB ch4 , 

respectively) were measured in the vicinity of the sampling or collection area using background yoke 

canisters and these will be subtracted from C sf6 and C ch4 , respectively. The ratio of molecular weights 

(MV) is used to account for the difference in density between the gases. 

Q ch4 = C ch4 – CB ch4 Q sf6 MW ch4 

C sf6 – CB sf6 

MW sf6 



EXPERIMENTAL DESIGN 

SAMPLING SITE 

The La du Bois Provincial Park grasslands served as the study location for this research. The La 

du Bois grassland area is a large multi-use area located on the outskirts of Kamloops, B.C. This area has 

served as an important grazing reserve for many years. Cattle use is managed in the park under five 

separate grazing licenses administered by the Kamloops Forest District, in accordance with the Range 

Act and the Forest Practices Code Act. The Lac du Bois Grasslands Park is in three Range Units: Dewdrop, 

Watching Creek and Lac du Bois, with each unit divided into a number of fenced pastures. Established in 

1976, the pasture rotation system serves to move cattle around, based on elevation, season of the year, 

availability of water, and actual conditions. In general, cattle move from the lowest pastures in the 

spring up to higher elevation forests outside the park in the summer, then back to the grassland 

pastures again in the fall before being gathered for return to home ranches. The lowest elevation 

pastures have an 18-month rest period with no grazing in a three year cycle (Ministry of Environment, 

Lands and Parks, 2000). 

The sample size consisted of six young cows. The cows had calibrated permeation tubes 

“installed” in the rumen in advance (seven days) of the animals (with calves) being placed into the low 

elevation grazing area in the spring. The sampling program consisted of four, five day sampling periods 

during the grazing season. The first two sampling periods occured in the spring (May, 2010) in the lower 

and mid-elevation areas ; and two sampling periods occured in the fall (late October 2010) in the same 

elevation locations as in the spring. 

Results 

The results from the methane analysis is displayed in Figure 7. The cattle grazing in Lac du Bois 

Grasslands Park produced approximately 364.06 L/day of methane during the course of the 

study, which is comparable to the amount of methane observed by other research groups for 

beef type animals (Ding et al. 2010). 



390 

380 

370 

360 

350 

340 

First Week 

Second Week 

Total 

330 

320 

Spring 2010 Fall 2010 

Figure 7. The amount of methane produce from 6 young cows in Lac du Bois grasslands during 

the 2010 grazing season in L/day 

It was observed that the six young cows produced more methane in the spring vs. the fall 

grazing period (369.63 vs. 358.50 L/day), which was surprising as we had anticipated more 

methane in the fall as the digestibility of the plants begins to drop off. However, the increase in 

methane observed in the spring might have been attributable to the metabolic stress of 

lactation, which often necessitates a dramatic increase in feed consumption. The cows had 

calves at foot, and were likely at peak lactation during the spring; whereas the metabolic 

demand from the nursing calves would have decreased in the fall, which was just prior to the 

normal weaning period. 

LIFE CYCLE ASSESSMENT 

Life Cycle Assessment (LCA) is a methodological framework for quantifying the environmental 

and health impacts occurring along the life cycle of a particular product, activity or service. LCA is used 

across agricultural, industrial, medical, corporate, marketing, retail, policy and research fields. LCA is a 

system-wide approach that typically encompasses the entire life cycle from “cradle-to-grave”, including 

the extraction of raw materials, processing, manufacturing, product use, disposal, and recycling 

(Keoleian, 1993). The results of an LCA analysis enable producers, distributors or retailers to identify and 

address areas along supply chains where the greatest reductions in environmental impacts are possible. 



LCA also allows consumers to make environmentally-conscious choices by comparing the impacts of 

different products, while policy makers have used LCA to guide legislation on a wide range of issues, 

including packaging (Anderson, 1994). 

LCA is typically comprised of four stages: 

1. Defining the purpose and system boundaries of the LCA (goal and scope 

definition). 

2. Modelling the activity and calculating resultant impacts (life cycle inventory). 

3. Interpreting results (life cycle impact assessment). 

4. Exploring improvements (improvement analysis). 

In order to develop a comprehensive footprint tool, it is necessary to gather specific data on the 

impacts associated with various factors along all relevant stages of an activity. All data must be 

transparent enough to distinguish between various production phases. The validity of any LCA relies 

upon inclusion of the most important factors (Jensen, 1997) (Environmental Protection Agency, 1993). 

To adequately assess the relative impact of an activity, and potential GHG mitigation strategies, 

it is necessary to use a whole system modelling approach (Schils, 2007). Such a life cycle assessment 

(LCA) encapsulates an entire system, and accounts for any changes in GHG emissions arising from a 

prospective mitigation practice (Beauchemin, 2010). Often reducing GHG emissions in one area of a 

farming system can lead to an unintended and undesirable increase in emissions in another sector – a 

whole systems approach avoids ill-advised practices based on preoccupation with a single GHG (Janzen, 

2006). In order to provide the information on relevant impacts to the environment of an activity, it is 

necessary to utilize LCA software tools, such as Holos, or SimaPro, that provides an interface with LCA 

data for the purposes of modelling and interpreting impacts. 

For this study, greenhouse gas (GHG) emissions and the environmental impact assessment of 

B.C. grass-fed beef were calculated using Holos 1.1.2, the whole-farm modelling software program 

developed by Agriculture and Agri-Food Canada (Little, 2008). Holos is an empirical model, with a yearly 

time step, based on the IPCC (2006) methodology, modified for Canadian conditions and farm scale. 

Holos estimates whole-farm GHG emission, calculating emissions for soil-derived N 2 O, enteric CH 4 , 

manure-derived CH 4 and N 2 O, CO 2 from on farm energy use and the manufacturing of fertilizer and 

herbicide, and CO 2 emission/removal from management changes in carbon stocks. This systems 



approach allows net whole-farm emissions to be calculated to account for management changes on any 

part of the farm (Beauchemin, 2010). 

To estimate GHG emissions from beef production in the central interior of B.C., we simulated 

Lac du Bois provincial park as a representative farm, incorporating current, conventional farming 

practices. To ensure we considered all aspects and associated emissions, we included all of the cattle 

present within the park during the 2010 grazing season, including the cow/calf pairs, stockers (grassers) 

and bulls. We modeled all pastures within Lac du Bois provincial park based on the Lac du Bois and 

Watching Creek Range Use plan and information compiled by Dr. Reg Newman, Range Scientist with the 

BC Ministry of Forests and Range. For simplicity purposes, we are reporting only the results from the 

Figure 8: Green house gas emissions from the Halston Pasture of Lac du Bois provincial park 

under both the native and intensive management scenarios. 

Halston Pasture, a pasture comprising of approximately 1332 ha of native grasslands, which 

was grazed by 464 cow calf pairs for 16 days, along with 7 bulls, as well as approximately 100 

steers for an additional nine days. The Holos model assumes that native grasslands have 

reached a “steady state” and the soils are no longer able to sequester any additional CO 2 . This 



was contrasted with a more intensive theoretical scenario, in which the pastures received more 

intensive management, in this case reseeding. Any land use changes in Holos triggers dramatic 

increases in the amount of CO 2 sequestered by the soils. Based on the two scenarios presented, 

the grasslands can either be an “emitter” of greenhouse gas emissions, or serve as a 

tremendous carbon sink, depending on the model inputs (see appendix). In the near future, we 

will incorporate the amount of CO 2 that is actually being sequestered based on empirical 

measurements . 

RELEVANCE 

Western range livestock producers have been through a 25 year period of large supplies of 

cheap grain. Cheap oil has effectively under-pinned the green revolution, resulting in the abundance of 

cheap grain (Holechek, 2009). During this era, meat production systems were reorganized to utilize this 

cheap grain supply by feeding it to large concentrations of confined domestic animals. This system has 

provided the consumer with an abundance of cheap meat, and artificially undermined the profitability 

of the producers. However, there are now compelling reasons to believe that the era of cheap and 

abundant food may be ending , driven by: depletion of fossil fuels, limits to the green revolution, losses 

of farmland to development, global warming, changing farm policies, imminent inflationary pressures, 

and continuing human population growth (Holechek, 2009). 

In recent years there has been a significant increase in world grain prices, and a major 

contributor to this trend has been the crop-based fuel ethanol program in the United States (Brown, 

2008). When oil rose above $50 USD a barrel in 2005, it became cost effective to convert grain into 

ethanol (Brown, 2008). Several other countries, including China, France, Spain, and Germany are also 

converting part of their grain crop to ethanol. Poor crop production is occurring in some Asian and 

African countries, for example, and this could further contribute to higher grain prices, and make food 

much more expensive throughout the world (Holechek, 2009). 

Since 2006, higher grain prices have adversely impacted range cattle prices because of the 

squeeze on feedlot profit margins. The feedlot operators have passed part of these costs onto the 

ranchers by lowering the prices they are willing to pay for cattle going from grass to the feedlot, and 

greatly reducing the number of days-on-feed. Meat imports have moderated the impact of higher grain 

prices on meat products in the grocery store. The continuing increase in grain prices (and fuel prices) 

could change meat production systems away from grain back to forage based systems (Holechek, 2009). 



The present system of confined animal meat production confronts other serious ecological 

challenges beyond those relating to energy (Pollan, 2006). Animal treatment concerns, as well as health 

issues associated with feedlot produced beef have generated a demand for meat from animals grown 

under natural (grass-fed) conditions. There is evidence that products from pastured animals contain 

higher levels of beneficial, essential omega-3 fatty acids. Health problems assigned to beef consumption 

may be due to the animal’s grain based diet, while conversely, the grass-fed animal’s meat may be 

nutritionally advantageous. More people are becoming believers in the health benefits of grass-fed 

meat, consumers are increasingly willing to pay a premium for the product, and it is anticipated the 

grass based beef production will continue to grow in British Columbia. 

This research has provided significant insight into the environmental footprint, the impact of 

cattle production on BC rangelands from an emissions perspective. While beef cattle do produce 

greenhouse gas emissions, especially from the enteric methane produced by the mature beef cows as 

measured empirically in this study; modelling work has clearly demonstrated that the grasslands of the 

central interior have huge potential to offset those emissions through carbon sequestration. The key 

outcome from this research was to providing the ranching community with insight with respect to their 

carbon footprint; to pinpoint the sources of greenhouse gas emissions from their operations, and to 

provide the information enabling them to effectively add value to their products by marketing and 

branding them as healthy, environmentally-friendly alternatives. If indeed the era of cheap oil and grain 

is ending, and consumers continue to demand a healthier, and more environmentally responsible 

product, it seems likely that the profitability of range livestock, and grass-fed production systems will 

improve, especially if it can be demonstrated that it is ecologically sustainable, and not contributing to 

the accumulation of greenhouse gas emissions. 

LITERATURE CITED 

Agency, Environmental Protection. (1993). Life Cycle Assessment: Inventory Guidelines and Principles. 

Office of Research and Development , EPA/600/R-92/245. 

Anderson, K. O. (1994). Life Cycle Assessment (LCA) of food products and production systems. In Trends 

in Food Science & Technology 5(5) (pp. 134-138). 

Beauchemin, K. e. (2010). Life cycle assessment of greenhouse gas emissions from beef production in 

western Canada: A case study. Agr. Sys. 

Beauchemin, K. M. (2009). Dietary mitigation of enteric fermentation from cattle. CAB Reviews: 

Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 4(35). 



Beauchemin, K. M. (2007). Methane abatement strategies for cattle. Can. J. Anim. Sci. 87 , 431-440. 

Boadi, D. W. (2002). Methane production from dairy and beef heifers fed forages differing in nutrient 

density using sulfur hexaflouride (SF6) tracer gas technique. Can. J. Anim. Sci. 82: 201-206. 

Brown, L. R. (2008). Mobilizing to save civilization: Plan B30. W.W. Norton & Company. 

Canadian Beef Export Federation. (2009). Government of Canada. 

Ding, X. Z., Long, R. J., Kreuzer, M., Mi, J. D., and B. Yang. 2010. Methane emissions from yak (Bos 

grunniens) steers grazing or kept indoors and fed diets with varying forage: concentrate ratio during the 

cold season on the Qinghai-Tibetan Plateau. Animal Feed Science and Technology. 162: 91-98. 

Gagen, E. D. (2007). Direct Global Warming Potentials. Applied Environmental Microbiology. 

Government of British Columbia. (2009). Ranching Task Force. British Columbia Ranching Task Force 

Report to Government. 

Holechek, J. L. (2009). Range Livestock Production, Food, and the future: A Perspective. Society for Range 

Mangement. 

IPCC. (2007). Climate Change: Synthesis Report; Summary for Policymakers. Intergovernmental Panel on 

Climate Change. 

IPCC. (2006). Guidelines for National GHG Inventories. Japan: IGES, Hayama, Kanagawa. 

IPCC. (2001). Third Assessment Report, Climate Change: The Scientific Basis Contribution of Working 

Group 1 to the Third Assessment Report of the IPCC. 

Janzen, H. e. (2006). A proposed approach to estimate and reduce net greenhouse gas emissions from 

whole farms. Can. J. Soil Sci. 86,401-418. 

Jensen, A. H. (1997). Life Cycle Asessment (LCA): A guide to approaches,experiences and information 

sources. Environmental Issues Series (6). 

Johnson, K. M. (1992). The use of SF6 as an inert gas tracer for use in methane measurements. J. Anim. 

Sci. 70 (Suppl. 1) . 

Johnson, K. W. (2007). The SF6 Tracer Technique: Methane Maeasurement from Ruminants. In H. a. 

Makkar, Measuring Methane Production from Ruminants (pp. 33-67). 

Kebreab, E. C.-R. (2006). Methane and Nitrous Oxide emissions from Canadain animal agriculture - a 

review. Can. J. Anim. Sci. 86: 135-158. 

Keoleian, G. &. (1993). Life Cycle Design Guidance Manual: Environmental Requirements and the Product 

System. Washington, DC: U.S Environmental Protection Agency. 



Little, S. L. (2008). HOLOS - a tool to estimate and reduce greenhouse gasses from farms. Agriculture and 

Agri-Food Canada. 

McGinn, S. B. (2006). Assessment of the sulphur hexafluoride (SF6) tracer technique for measuring 

enteric methane emissions from cattle. J. Environ. Qual. 135: 1689-1691. 

Ministry of Environment, Lands and Parks. (2000). Lac du Bois Grasslands Park - Management Plan 

Background Document. Kamloops, BC. 

Moss, A. J. (2000). Methane production by ruminants: its contribution to global warming. Ann Zootech 

49:231-252. 

PFRA, Government of Canada. (1996). 

Pinares-Patino, C. H. (2007a). Evaluation of the sulfur hexafluoride tracer technique for methane 

emission measurement in forage-fed sheep. Proc. N.Z. Soc. Anim. Prod. 67: 431-435. 

Pinares-Patino, C. M. (2007). The SF6 tracer technique for measurements of methane eimission from 

cattle - effect of tracer permeation rate. Can. J. Anim. Sci. 88: 309-320. 

Pollan, M. (2006). The omnivore's dilemma. Penguin Books. 

Rance, L. (2010). How Green is Grass-Fed Beef? Winnipeg Free Press. 

Schils, R. O. (2007). A review of farm level modelling approaches for mitigating greenhouse gas 

emissions from ruminant livestock systems. Livest. Sci. 112, 240-251. 

Steinfeld, H. W. (2007). The role of livestock production in carbon and nitogen cycles. Annu. Rev. 

Environ. Resour. 32 , 271-294. 

Stejian, V. L. (2010). Measurement and prediction of enteric methane emission. International Journal of 

Biometeorology. 

Subak, S. (1999). Global environmental costs of beef production. Ecological Economics (30) 79-91. 

Ulyatt, M. B. (1999). Accuracy of SF6 trcer technology and alternatives for field measurments. Australian 

Journal Of Agricultural Research 50(8) , 1329-1334.

Team 7 Report - Ministry of Forests, Lands and Natural Resource ...

Create successful ePaper yourself

Delete template?

Save as template?