Getahun Legesse

Greenhouse gas emissions of Canadian beef production in 1981 as compared with 2011

The present study compared the greenhouse gas (GHG) emissions, and breeding herd and land requirements of Canadian beef production in 1981 and 2011. In the analysis, temporal and regional differences in feed types, feeding systems, cattle categories, average daily gains and carcass weights were considered. Emissions were estimated using life-cycle assessment (cradle to farm gate), based primarily on Holos, a Canadian whole-farm emissions model. In 2011, beef production in Canada required only 71% of the breeding herd (i.e. cows, bulls, calves and replacement heifers) and 76% of the land needed to produce the same amount of liveweight for slaughter as in 1981. Compared with 1981, in 2011 the same amount of slaughter weight was produced, with a 14% decline in CH4 emissions, 15% decline in N2O emissions and a 12% decline in CO2 emissions from fossil fuel use. Enteric CH4 production accounted for 73% of total GHG emissions in both years. The estimated intensity of GHG emissions per kilogram of liveweight that left the farm was 14.0 kg CO2 equivalents for 1981 and 12.0 kg CO2 equivalents for 2011, a decline of 14%. A significant reduction in GHG intensity over the past three decades occurred as a result of increased average daily gain and slaughter weight, improved reproductive efficiency, reduced time to slaughter, increased crop yields and a shift towards high-grain diets that enabled cattle to be marketed at an earlier age. Future studies are necessary to examine the impact of beef production on other sustainability metrics, including water use, air quality, biodiversity and provision of ecosystems services.

Economic performance of small ruminants in mixed-farming systems of Southern Ethiopia

This study evaluates the household income contribution and the profitability of traditional small ruminant enterprises in two mixed-farming systems of southern Ethiopia (viz. Adilo and Kofele). Small ruminant production is an integral part of mixed systems in the Ethiopian highlands. The assessment of the current economic performance of small ruminants indicates production-related opportunities and constraints and provides baseline data against which the success of future interventions can be measured. Detailed information on economic parameters was gathered through a 1-year period of flock and household monitoring (155 households) between September 2005 and August 2006. Structured surveys were conducted with the participating households to elicit information on income-expense details of small ruminant and other agricultural enterprises. Small ruminants contributed considerably to cash income and to a limited extent to human nutrition especially when other sources were in short supply. The annual profit per animal ranged from 20 to 37 Ethiopian Birr. The return to capital was 17% in Kofele and 29% in Adilo, with both values vastly exceeding the national interest rate. The sale of small ruminants contributed to 39% and 23% of total farm cash income among small ruminant keepers in Adilo and Kofele, respectively. Sale prices are highest before holidays. Researches should target at how to use available feed resources in a timely and cost-effective fashion to make use of the seasonal market opportunities.

Water use intensity of Canadian beef production in 1981 as compared to 2011

The amount of beef produced per animal in Canada increased significantly from 1981 to 2011, due to enhanced production efficiency and increased carcass weight. This study examined the impact of improvements in production efficiency on water use intensity over this period. Temporal and regional differences in cattle categories, water use for drinking, feed production and meat processing, feeding systems, average daily gains, and carcass weight were considered in the analysis. Potential evapotranspiration (PET) was estimated by the National Drought Model (NDM) from 679 weather stations across Canada using the Priestley and Taylor equation. To adjust PET estimates for each crop included in cattle diets, FAO crop coefficients were used to calculate total feed water demand. Estimates of drinking water consumed by a given class of cattle accounted for physiological status, body weight and dry matter intake as well as ambient temperature. In both years, drinking water accounted for less than 1% of total water use with precipitation (i.e., green water) included for feed and pasture production. With exclusion of green water, drinking water accounted for 24% and 21% of total water use for Canadian beef production in 1981 and 2011, respectively. The estimated intensity of blue water (surface and groundwater) use per kilogram of boneless beef was 577L in 1981 and 459 in 2011, a 20% decline. The observed reduction in water use intensity over the past three decades is attributed to an increase in average daily gain and slaughter weight, improved reproductive efficiency, reduced time to slaughter as well as improvements in crop yields and irrigation efficiency. Given that feed production accounts for the majority of water use in beef production, further advances may be achieved by improving feeding efficiencies and reducing water use per unit of feed crop and pasture production.

Off-Stream Watering Systems and Partial Barriers as a Strategy to Maximize Cattle Production and Minimize Time Spent in the Riparian Area.

Simple Summary The implementation of off-stream waterers (OSW) may reduce the amount of time cattle spend in riparian areas, thus minimizing impacts such as removal of vegetation, soil compaction, and deterioration in water quality. Furthermore, when used with natural barriers as a partial exclusion method, these management strategies may offer a cost-effective alternative to completely excluding cattle via streambank fencing. This study was conducted to determine the impact of OSW and barriers on animal performance and watering behavior. The presence of OSW had no significant effect on cow and calf weights averaged over the grazing season. Although the results were not consistent over the periods and locations, the data provided some indication of the efficacy of the natural barriers on deterring cattle from the riparian area. Cattle watered at the OSW when available, but they did not use the OSW exclusively. The observed inconsistency may, in part, be attributed to the environmental conditions present during this field trial. Abstract A study was conducted in 2009 at two locations in Manitoba (Killarney and Souris), Canada to determine the impact of off-stream waterers (OSW) with or without natural barriers on (i) amount of time cattle spent in the 10 m buffer created within the riparian area, referred to as the riparian polygon (RP), (ii) watering location (OSW or stream), and (iii) animal performance measured as weight gain. This study was divided into three 28-day periods over the grazing season. At each location, the pasture—which ranged from 21.0 ha to 39.2 ha in size—was divided into three treatments: no OSW nor barriers (1CONT), OSW with barriers along the stream bank to deter cattle from watering at the stream (2BARR), and OSW without barriers (3NOBARR). Cattle in 2BARR spent less time in the RP in Periods 1 (p = 0.0002), 2 (p = 0.1116), and 3 (p < 0.0001) at the Killarney site compared to cattle in 3NOBARR at the same site. Cattle in 2BARR at the Souris site spent more time in the RP in Period 1 (p < 0.0001) and less time in Period 2 (p = 0.0002) compared to cattle in 3NOBARR. Cattle did use the OSW, but not exclusively, as watering at the stream was still observed. The observed inconsistency in the effectiveness of the natural barriers on deterring cattle from the riparian area between periods and locations may be partly attributable to the environmental conditions present during this field trial as well as difference in pasture size and the ability of the established barriers to deter cattle from using the stream as a water source. Treatment had no significant effect (p > 0.05) on cow and calf weights averaged over the summer period. These results indicate that the presence of an OSW does not create significant differences in animal performance when used in extensive pasture scenarios such as those studied within the present study. Whereas the barriers did not consistently discourage watering at the stream, the results provide some indication of the efficacy of the OSW as well as the natural barriers on deterring cattle from the riparian area.

Effect of changes in management practices and animal performance on ammonia emissions from Canadian beef production in 1981 as compared to 2011

Abstract: The present study compared ammonia (NH3) emissions from Canadian beef production in 1981–2011. Temporal and regional differences in cattle categories, feed types and management systems, average daily gains, carcass weights, and manure handling practices were considered. A scenario-based sensitivity analysis in 2011 estimated the impact of substituting corn dried distillers’ grains with solubles (DDGS) for grain in feedlot diets. On average, 22% of the total nitrogen (N) intake was lost as ammoniacal nitrogen (NH3-N) in both years. Manure emission sources were consistent across years, averaging 12%, 40%, 28%, and 21% for grazing, confinement, storage, and land spreading, respectively. Emissions per animal in 1981 and 2011 were 16.0 and 18.4 kg NH3 animal-1 yr-1, respectively. On an intensity basis, kilogram of NH3 emitted per kilogram of beef decreased 20%, from 0.17 in 1981 to 0.14 in 2011. This reduction was attributed to increases in reproductive efficiency, average daily gain and carcass weight, and improved breeding herd productivity. In 2011, substituting DDGS for grain in feedlot diets increased total NH3 emissions and losses per animal. Although addition of by-products from the bioethanol industry can lower diet costs, it will be at the expense of an increase in NH3 emissions.

Economic and greenhouse gas emissions impacts of doubling of ofrage area in Manitoba, Canada

Forages are an important part of crop rotations in many agricultural systems. In Manitoba, Canada, almost 40% of the 7 million ha agricultural area is devoted to forage crops and pastures. Use of legume forages to reduce fertilizer cost to producers can improve soil quality and productivity and may provide more options for diversification of the agricultural production system. We tested that whether a twofold increase in forage production for feeding beef cattle would change greenhouse gas (GHG) emissions for the agriculture and agri-food system and economic returns at the farm in the year 2011. The forage resulting from the increased production was fed to beef cattle. The GHG emissions were calculated using Intergovernmental Panel on Climate Change Tiers 1 and 2 methodologies and economic returns through an optimization algorithm maximizing net financial margin. The results suggest that the economic effects, in terms of farm-level profitability, may be minimal (decrease of 0.6%) but are likely sensitive ...

Economic and greenhouse gas emission impacts of doubling of forage area in Manitoba, Canada1

Abstract: Forages are an important part of crop rotations in many agricultural systems. In Manitoba, Canada, almost 40% of the 7 million ha agricultural area is devoted to forage crops and pastures. Use of legume forages to reduce fertilizer cost to producers can improve soil quality and productivity and may provide more options for diversification of the agricultural production system. We tested that whether a twofold increase in forage production for feeding beef cattle would change greenhouse gas (GHG) emissions for the agriculture and agri-food system and economic returns at the farm in the year 2011. The forage resulting from the increased production was fed to beef cattle. The GHG emissions were calculated using Intergovernmental Panel on Climate Change Tiers 1 and 2 methodologies and economic returns through an optimization algorithm maximizing net financial margin. The results suggest that the economic effects, in terms of farm-level profitability, may be minimal (decrease of 0.6%) but are likely sensitive to the market conditions in different years. Doubling the forage area and increasing the cattle herd increased GHG emissions from agriculture by 7.6%, mostly because of methane from enteric fermentation by cattle. The GHG emissions were mitigated by carbon sequestration in soil, but this is likely ephemeral, suggesting that the longer term emissions would be even greater. However, a twofold increase in forage production implies less energy use, change in water dynamics, and a reduction in the use of nitrogenous fertilizer, which could be beneficial for ecosystem services, and needs to be assessed.