This study assessed the environmental impacts of beef cattle production and their effects on the overall sustainability of Canadian beef production. Cradle to farm gate, cradle to processor’s gate, and cradle to consumer plate life cycle assessments were carried out to quantify greenhouse gases (GHG), resource use (i.e., water, land, and fuel), and potential water and air pollution (i.e., freshwater eutrophication, terrestrial acidification, and photochemical oxidants formation). Across the production chain, feed production had the greatest impact on most environmental indicators. The GHG intensity without dairy meat was estimated as 10.4 kg CO₂-eq per kg of live weight (LW), corresponding to 32.8 kg CO₂-eq per kg of consumed boneless beef. Including dairy meat reduced GHG intensity by 5.8% (0.6 kg CO₂-eq kg LW^–1) compared to when it was excluded. Other environmental metrics per kg of LW were 657 L, 38.7 m² annual crop-eq, 0.4 kg oil-eq, 2.6 kg P-eq, 115.9 kg SO₂-eq, and 8.7 kg NO_x-eq for water use, land use, fossil fuel use, freshwater eutrophication, terrestrial acidification, and photochemical oxidants, respectively. Data provide benchmarks for use in future regional and national assessments that are designed to encourage the adoption of sustainable management practices that can lower the environmental footprint of Canadian beef production.

The objective of this study was to evaluate the effects of using conventional productivity-enhancing technologies (PETs) with or without other natural PETs on the growth performance, carcass traits, and environmental impacts of feedlot cattle. A total of 768 cross-bred yearling steers (499 ± 28.6 kg; n = 384) and heifers (390 ± 34.9 kg; n = 384) were offered a barley grain-based basal diet and divided into implanted or non-implanted groups. Steers were then allocated to diets that contained either: (i) no additive (control); natural feed additives including (ii) fibrolytic enzymes (Enz), (iii) essential oil (Oleo), (iv) direct-fed microbial (DFM), (v) DFM + Enz + Oleo combination; conventional feed additives including (vi) Conv (monensin, tylosin, and beta-adrenergic agonists [βAA]); or Conv with natural feed additives including (vii) Conv + DFM + Enz; (viii) Conv + DFM + Enz + Oleo. Heifers received one of the first three dietary treatments or the following: (iv) probiotic (Citr); (v) Oleo + Citr; (vi) Melengesterol acetate (MGA) + Oleo + βAA; (vii) Conv (monensin, tylosin, βAA, and MGA); or (viii) Conv + Oleo (ConvOleo). Data were used to estimate greenhouse gas (GHG) and ammonia (NH₃) emissions, as well as land and water use. Implant and Conv-treated cattle exhibited improvements in growth and carcass traits as compared to the other treatments (P < 0.05). Improvements in the performance of Conv-cattle illustrated that replacing conventional feed additives with natural feed additives would increase both the land and water required to satisfy the feed demand of steers and heifers by 7.9% and 10.5%, respectively. Further, GHG emission intensity for steers and heifers increased by 5.8% and 6.7%, and NH₃ emission intensity by 4.3% and 6.7%, respectively. Eliminating the use of implants in cattle increased both land and water use by 14.6% and 19.5%, GHG emission intensity by 10.5% and 15.8%, and NH₃ emission intensity by 3.4% and 11.0% for heifers and steers, respectively. These results demonstrate that the use of conventional PETs increases animal performance while reducing the environmental impacts of beef production. Restricting use would increase the environmental footprint of beef produced for both domestic and international markets.

Use of productivity-enhancing technologies (PET: growth hormones, ionophores, and beta-adrenergic agonists) to improve productivity has recently garnered public attention regarding environmentally sustainability, animal welfare, and human health. These consumer perceptions and increased demand for PET-free beef offer opportunities for the beef industry to target niche premium markets, domestically and internationally. However, there is a need to critically examine the trade-offs and benefits of beef raised with and without the use of PETs. This review contains a summary of the current literature regarding PET products available. The implications of their use on resource utilization, food safety and security, as well as animal health and welfare are discussed. Furthermore, we identified gaps in knowledge and future research questions related to the sustainability of these technologies in beef production systems. This work highlights the tradeoffs between environmental sustainability of beef and supplying the dietary needs of a growing population.

The study determined in vitro enteric methane (CH₄) emission potential of whole-plant cereal (WPC) forages in relationship to nutrient composition, degradability, and rumen fermentation. Two varieties of each WPC (barley, oat, triticale, and wheat) were harvested from two field replications in each of two locations in central Alberta, Canada, and an in vitro batch culture technique was used to characterize gas production (GP), fermentation, and degradability. Starch concentration (g/kg dry matter (DM)) was least (p < 0.001) for oat (147), greatest for wheat (274) and barley (229), and intermediate for triticale (194). The aNDF concentration was greater for oat versus the other cereals (531 vs. 421 g/kg DM, p < 0.01). The 48 h DM and aNDF degradabilities (DMD and aNDFD) differed (p < 0.001) among the WPCs. The DMD was greatest for barley, intermediate for wheat and triticale, and least for oat (719, 677, 663, and 566 g/kg DM, respectively). Cumulative CH₄ production (MP; mL) from 12 h to 48 h of incubation was less (p < 0.001) for oat than the other cereals, reflecting its lower DMD. However, CH₄ yield (MY; mg of CH₄/g DM degraded) of barley and oat grown at one location was less than that of wheat and triticale (28 vs. 31 mg CH₄/g DM degraded). Chemical composition failed to explain variation in MY (p = 0.35), but it explained 45% of the variation in MP (p = 0.02). Variation in the CH₄ emission potential of WPC was attributed to differences in DMD, aNDFD, and fermentation end-products (R² ≥ 0.88; p < 001). The results indicate that feeding whole-plant oat forage to ruminants may decrease CH₄ emissions, but animal performance may also be negatively affected due to lower degradability, whereas barley forage may ameliorate emissions without negative effects on animal performance.

Greenhouse gas (GHG) and ammonia (NH₃) emissions, land and water use associated with feedlot cattle ( n = 40 hd treatment⁻¹ trial⁻¹) treated with or without productivity-enhancing technologies were modelled for a multiyear study ( n = 4). Heifers (H) were assigned to the following treatments: (1) implanted (HTBA); (2) provided with melengestrol acetate (HMGA); (3) nonimplanted control, weight-adjusted (CON_Adj) to achieve the same final carcass weight (CW) as 1 (HCON_AdjTBA); or (4) CON_Adj to achieve the CW as 2 (HCON_AdjMGA). Steers (S) were assigned as follows: (1) implanted (STBA); (2) implanted and provided with ractopamine hydrochloride (SRAC; conducted in the last 2 years); (3) CON_Adj to achieve the same CW as 1 (SCON_AdjTBA); or (4) CON_Adj to achieve the same CW as 2 (SCON_AdjRAC). The GHG and NH₃ emissions from HTBA, HMGA, STBA, and SRAC were 3.8%, 3.0%, 10.1%, and 8.5% lower and 4.3%, 2.9%, 7.4%, and 7.6% lower, respectively, than the respective control cattle. The land required to produce feed was also reduced by 6.6%, 4.8%, 9.9%, and 10.9%, while water use was reduced by 6.4%, 4.8%, 10.1%, and 11.1% for HTBA, HMGA, STBA, and SRAC, respectively. This modelling study clearly demonstrates that conventional beef production systems have a lower environmental footprint than nonconventional systems.

Environmental impacts of recently weaned Angus–continental steers raised without (NAT) or with (CON) productivity-enhancing technologies (PETs) in the form of hormonal implants (Ralgro®, Revalor®-G Revalor®-S, tylosin, monensin) were investigated. Heavy steers (295 ± 11 kg; SD) were direct finished, Medium steers (250 ± 11 kg) were confined backgrounded (98 ± 8 days) before finishing, and Light (205 ± 11 kg) steers were backgrounded (195.5 ± 7.5 days) and summer-grazed (67.5 ± 12.5 days) before finishing. Use of PETs resulted in six management strategies ( n = 40 hd treatment⁻¹): Heavy conventional (HCON), Heavy natural (HNAT), Medium conventional (MCON), Medium natural (MNAT), Light conventional (LCON), and Light natural (LNAT). The NAT steers were not implanted, while the CON steers were implanted at arrival, at the start of backgrounding and finishing. Steers were finished to a target weight of 646 kg. CON steers had 10%–13% lower greenhouse gas emissions (kg CO₂e), 10%–32% lower NH₃ emissions, 9%–22% lower land requirements (ha), and 12%–25% lower water use (m³) per kg boneless beef compared to NAT steers. Further, HCON steers had a lower environmental impact compared to MCON and LCON. In conclusion, PETs lowered the environmental impact of all beef production systems.