Improving feed efficiency with the EcoFeed index reduces greenhouse gas emissions in dairy cattle

Journal of Dairy Science · 2026-02-10

Genetic selection for feed efficiency in dairy cattle is a promising strategy to mitigate environmental emissions reduce the environmental footprint of dairy production.In this study, genetic selection for residual feed intake (RFI) using the EcoFeed index developed by STgenetics was evaluated as a tool to improve feed efficiency and reduce GHG emissions.A life cycle assessment approach was used to quantify emissions from feed production, enteric fermentation, and manure management under 3 RFI selection scenarios: baseline (average genomic RFI [gRFI]), a 1-SD improvement in the genomic breeding value for RFI in heifers and cows (gRFIheifer and gRFIcow), and fa 3-SD improvement in gRFIheifer and gRFIcow.As expected, selection for improved gRFI led to enhanced feed efficiency.Animals with a 1-SD improvement in gRFI consumed 2.73% less feed over their lifetime, whereas those with a 3-SD improvement consumed 8.2% less, with no impact on productivity.These improvements in feed efficiency translated into a 2.42% reduction in lifetime CO 2 equivalent (CO 2 e) emissions (35,769 vs. 34,902 kg CO 2 e) in the 1-SD group, and a 7.31% reduction (35,769 vs. 33,153 kg CO 2 e) in the 3-SD group.Enteric CH 4 emissions were the largest contributor to the lifetime carbon footprint, accounting for 38.9% of total emissions in the baseline scenario, highlighting the importance of genetic selection for methane mitigation.Feed production and manure management accounted for 17.51% and 32.53% of total emissions, respectively.These findings suggest that genetic selection for RFI using the EcoFeed index significantly reduces the carbon intensity of milk production through improved lifetime feed efficiency and subsequently reduced feed intake per unit of milk production, establishing it as a key strategy for reducing GHG emissions the dairy sector.

Variations in methane emissions associated with rumen accessible fatty acids, dietary characteristics, and ruminal fermentation in lactating dairy cows – a meta-analytical approach

Journal of Dairy Science · 2026-04-01

emission in dairy cows.

Weather-driven US milk yield losses and economic damages revealed by 9 million cows

Research Square · 2026-01-21

Climate neutral dairy in California? A study based on life cycle assessment and radiative forcing

Journal of Dairy Science · 2026-04-01

Ruminants play a key role in achieving the global climate goal of limiting surface temperature increase to 1.5 to 2C by 2100.In California, the dairy sector is subject to ambitious methane (CH 4 ) reduction targets, specifically, a 40% decrease by 2030 from 1990 levels, through strategies such as alternative manure management, anaerobic digestion and anti-methanogenic feed additives.These mitigation measures are intended to put California dairy on a path toward climate neutrality.However, questions remain: Are current technological improvements enough to achieve climate neutrality in dairy?What is the role of non-CH 4 greenhouse gases (GHG), such as carbon dioxide (CO 2 ) and nitrous oxide (N 2 O), in shaping long-term climate impacts?This study analyses the historical climate impact of California dairy from 1950 until 2020, and forecasts different scenarios to 2030, 2050 and 2100 based on current public policies and technological development.The analysis integrates Life Cycle Assessment (LCA) with the recently developed Radiative Forcing Climate Footprint (RFCF), a metric that quantifies climate impact over time in terms of radiative forcing (W/m 2 ), later translated into temperature change (C).The RFCF results were further processed to assess climate neutrality and stability, as well as the sector's relative contribution to achieving global climate goals.Results indicate that projected reductions in CH 4 emissions drive a rapid decline in short-and middle-term climate impacts, decreasing from 1.67 mW/m 2 in 2020 to 1.32 mW/m 2 in 2050 and 0.98 mW/m 2 in 2100 under the lowest-emissions scenario.However, achieving long-term climate goals is likely to require additional reductions on CO 2 and N 2 O emissions.The study also identified the need for systemic changes in livestock and food production systems to achieve climate neutrality in the 21st Century.

Energy requirements of growing small ruminants raised for meat production in contrasting climatic regions: a meta-analysis

Translational Animal Science · 2025-01-01 · 1 citations

Abstract The objective of this meta-regression was to evaluate the influence of ruminant species, sex, and climatic regions on the metabolizable energy (ME) requirements for maintenance (MEm) and weight gain (MEg) in growing small ruminants raised for meat production across different climatic regions. Data included 655 and 337 treatment means from 173 and 99 studies on sheep and goats, respectively. Metabolizable energy intake (MEI; MJ/kg^0.75) was regressed against average daily gain (ADG; g/kg^0.75), with the study included as a random effect. The analysis found that MEm was not affected by species (P = 0.50), but MEg (MJ/g ADG) was significantly different between species (P = 0.02), with sheep requiring 0.032 (± 0.002) and goats 0.026 (± 0.002) MJ/g ADG. Sex did not affect MEm in either species (P ≥ 0.32). However, in goats, intact males had a greater MEg (P = 0.02) than females (0.030 ± 0.003 vs. 0.013 ± 0.006 MJ/g ADG). MEm was lower (P = 0.03) in small ruminants raised in subtropical regions (0.497 ± 0.046 MJ/kg^0.75) compared to those in semi-arid (0.600 ± 0.038 MJ/kg^0.75) and tended to be lower than those in arid regions (0.529 ± 0.050 MJ/kg^0.75). However, these differences disappeared when adjusting for maturity, diet composition, digestibility, or altitude. MEg was significantly higher (P < 0.05) in animals raised in arid regions (0.032 ± 0.006 MJ/g ADG) compared to those in Mediterranean (0.009 ± 0.004 MJ/g ADG) or semi-arid regions (0.009 ± 0.004 MJ/g ADG) after adjusting for diet composition and digestibility. Similarly, ruminants in Mediterranean regions had lower MEg (0.019 ± 0.004 and 0.009 ± 0.004 MJ/g ADG) than those in tropical regions (0.033 ± 0.002 and 0.024 ± 0.002 MJ/g ADG), respectively after adjusting for maturity, diet composition, and digestibility. MEg in semi-arid regions was consistently lower than in tropical regions, regardless of the covariates tested. For predictive purposes, the global model exhibited the best accuracy (CCC = 0.57 and RSR = 0.79), comparable to the model derived specifically for the tropical region (CCC = 0.58 and RSR = 0.80). This meta-analysis provides a comprehensive evaluation of species-specific differences in ME requirements in small ruminants while recognizing the challenges posed by confounding effects and climatic variability inherent in global datasets. The analysis suggests that animals raised in tropical conditions may have lower MEm than current feeding systems that use data from temperate climates.

A meta-analysis of 3-nitrooxypropanol effects on methane production and yield in beef cattle

bioRxiv (Cold Spring Harbor Laboratory) · 2025-08-25

Abstract Beef cattle are a major source of enteric methane (CH 4 ) emissions, a potent greenhouse gas (GHG). The feed additive 3-nitrooxypropanol (3-NOP) has been shown to reduce CH 4 emissions by inhibiting methyl-coenzyme M reductase, an enzyme critical to methanogenesis in archaea. This study aimed to quantify the effects of 3-NOP on CH 4 production (g/d) and yield (g/kg DM intake; DMI) in beef cattle and to evaluate how diet composition influences the mitigation response. A systematic literature review identified 17 peer-reviewed in vivo studies, yielding 45 treatment means. Treatment effects were expressed as absolute and relative mean differences versus control groups. Predictor variables included 3-NOP dose, 3-NOP dose 2 , DMI, dietary concentration of NDF, CP, starch, fat, and organic matter (OM), roughage proportion, BW, and dietary inclusion of monensin (yes/no). Four types of models were developed, all including the intercept and 3-NOP dose as fixed predictors, differing as follows: (model 1) optional inclusion of 3-NOP dose 2 when P < 0.10; (model 2) model 1 plus pre-inclusion of NDF concentration; (model 3) pre-inclusion of NDF concentration plus additional predictors (pairwise r ≤ 0.5) that significantly improved model accuracy ( P < 0.10); and (model 4) additional predictors selected under the same criteria as model 3, without pre-inclusion of NDF concentration. For models 3 and 4, a maximum of 5 predictors were considered and evaluated using leave-one-out cross-validation. Across studies, 3-NOP doses ranged from 32 to 338 mg/kg of DM. On average, 3-NOP reduced CH 4 production by 49.9 ± 28.61 g/d (36.2 ± 24.42%) and CH 4 yield by 5.3 ± 3.61 g/kg DMI (33.2 ± 25.54%). The best models were selected based on biological interpretability, statistical significance, and predictive accuracy (as measured by RMSE) and included 3-NOP dose, dietary NDF concentration, DMI, and BW as significant predictors (the latter two only for absolute CH 4 production). Mitigation efficacy increased with higher DMI and declined with increasing NDF concentration and BW. Absolute reductions of 53.1 g/d and 5.88 g/kg of DMI, and relative reductions of 37.6% in CH 4 production and 35.0% in CH 4 yield were predicted when moderators were at their mean value (3-NOP dose = 134.4 mg/kg of DM; NDF concentration = 32.8% of DM; DMI of 8.6 kg/d). These results support the effectiveness of 3-NOP in mitigating enteric CH 4 emission in beef cattle and provide quantitative models to be used in assessment tools and GHG inventory methodology. Implications The feed additive 3-nitrooxypropanol effectively reduces enteric methane emissions in beef cattle. This meta-analysis found average reductions of 36.2% in methane production and 33.2% in methane yield. Efficacy depended on diet composition; declining with increasing NDF concentration for both methane production (g/d) and yield (g/kg of DM intake; DMI). Greater DMI increased absolute methane production reduction but did not influence absolute methane yield reduction or relative reduction of both methane production and yield. These results support the targeted use of 3-nitrooxypropanol as a mitigation strategy and provide empirical models to inform greenhouse gas inventories and carbon accounting.

The effect of Rumin8 Investigational Veterinary Product—a bromoform based feed additive—on enteric methane emissions, animal production parameters, and the rumen environment in feedlot cattle

Translational Animal Science · 2025-01-01 · 13 citations

Abstract The livestock sector plays a crucial role in mitigating global climate change by reducing greenhouse gas emissions, with enteric fermentation as the largest source. Although various approaches have been proposed to decrease enteric methane (CH4) emissions, feed additives containing bromoform (CHBr3) have shown promise with minimal impact on animal production parameters. This study aimed to evaluate the effects of two Rumin8 Investigational Veterinary Products (IVP) containing synthetic CHBr3 on enteric gas emissions, animal production parameters, and the rumen environment. Twenty-four Angus beef steers were randomly assigned to one of three treatment groups: Control, Oil (8 mL Rumin8 oil IVP/kg DMI), and Powder (1.2 g Rumin8 powder IVP/kg DMI). The Rumin8 oil IVP treatment resulted in a CHBr3 intake of 32.2 mg/kg DMI, while the Rumin8 powder IVP provided a CHBr3 intake of 2.0 mg/kg DMI during weeks 1–8. In week 9, a new batch of Rumin8 powder IVP increased the CHBr3 intake to 17.9 mg/kg DMI. The Oil group exhibited 95.0%, 95.0%, and 96.1% reductions in CH4 production (g/day), yield (g/kg DMI), and intensity (g/kg average daily gain), respectively, accompanied by 925%, 934%, and 858% increases in H2 production, yield, and intensity, respectively. Neither treatment significantly affected animal production parameters or rumen environment variables. These findings suggest that Rumin8 oil IVP containing synthetic CHBr3 has the potential to reduce enteric CH4 emissions. This warrants further investigation, as this is the first published in vivo study to assess compound efficacy.

A meta-analysis of effects of seaweed and other bromoform containing feed ingredients on methane production, yield, and intensity in cattle

bioRxiv (Cold Spring Harbor Laboratory) · 2025-05-20 · 4 citations

ABSTRACT Methane (CH 4 ) emissions from ruminants contribute significantly to global GHG emissions. Bromoform (CHBr 3 )-containing feed ingredients, such as Asparagopsis seaweed, have emerged as promising tools to reduce enteric CH 4 emissions. This meta-analysis quantitatively assessed the effects of CHBr 3 -containing seaweeds and synthetic CHBr 3 -based additives on CH 4 production (g/day), CH 4 yield (g/kg DMI), and DMI, as well as CH 4 intensity (g/kg product) and production (milk or daily gain in dairy and beef cattle, respectively). Data were collected from 14 studies, with 39 treatment mean differences for CH 4 production, comprising both beef and dairy cattle fed CHBr 3 -containing ingredients, while accounting for dose, DMI, and diet composition. The random-effects model’s estimates revealed that at an average CHBr 3 dose of ≈28.3 mg/kg DM, CH 4 production was reduced by 47.3%, CH 4 yield by 43.3%, and CH 4 intensity by 39.0%, with increases in CHBr 3 dose resulting in larger efficacy in mitigating CH 4 emissions. The efficacy of CHBr 3 was influenced by cattle type, with greater mitigation effects in beef cattle than dairy catle, and by dietary composition, with greater reductions observed in diets higher in starch, whereas higher NDF levels attenuate its effect. At the average CHBr 3 dose, estimated DMI was significantly reduced by 6.45% and 3.26% in dairy and beef cattle, respectively. The significant reduction in DMI did translate into a significant effect on milk yield (-4.60%) at average CHBr 3 dose. Carrier type (oil vs. biomass), measurement technique and cattle type influenced the results. Oil carrier potentially leading to more pronounced reductions, particularly for CH 4 intensity, respiration chambers yielded significantly greater CH 4 reductions compared to other methods, and beef cattle showed stronger mitigation effects than dairy cattle. This study highlights the CH 4 mitigating potential of CHBr 3 -containing feed ingredients, providing predictive models to optimize CH 4 reduction strategies under diverse production conditions. Future research should address long-term effects, dietary optimization, and practical implementation.

Neddylation inhibition affects cell proliferation and steroidogenesis in sheep follicular granulosa cells

Theriogenology · 2025-02-18

294 Pelleted seaweed (Asparagopsis taxiformis) effectively reduces enteric methane emissions in grazing beef cattle.

Journal of Animal Science · 2025-10-01

Abstract The ruminant livestock sector contributes to global greenhouse gas emissions. Thus, there is a need to develop novel mitigation strategies, especially for pasture-based systems as less than half of the identified strategies are applicable to grazing systems. This study aimed to examine the use of pelleted bromoform-containing seaweed (Asparagopsis taxiformis) marketed as Brominata, as an enteric methane (CH4) inhibitor in grazing beef cattle under real-world farm conditions. The study was conducted at the Selkirk division of Matador Ranch and Cattle in Dillon, Montana, USA, situated in a semi-arid climate with cold, dry winters and hot, wet summers. Twenty-four crossbred Wagyu-Angus beef steers, with an average liveweight of 399 ± 21.7 kg, were allocated to two treatment groups: Control and Brominata. Measurements of CH4, carbon dioxide (CO2), and hydrogen (H2) emissions were conducted using the GreenFeed system which also was used to administer the pelleted supplements. The control group received a pellet composed of 65% wheat mids, 15% molasses, and 20% bentonite (CHS Nutrition, Great Falls, Montana, USA). The Brominata group received a pellet containing Brominata (20%, Blue Ocean Barns, Kailua Kona, HI, USA), distillery solubles (15%), wheat mids (65%), a palatability enhancer (Inhace, 0.25%, Qualitech, Chaska, Minnesota, USA), molasses coating, and wheat mids dusting. The bromoform concentration in the pellets was 1.4 mg g/dry matter. The study was conducted in an intensive irrigated pasture, where the steers remained together throughout the experiment. Central pivot irrigation and rotational grazing management were used with a fixed stocking rate. Statistical analysis was conducted using SAS 9.4, with a model incorporating fixed effects for treatment, time, their interaction, and a covariate, while accounting for animal variations as a random effect within each phase. Three phases of bromoform intake were identified: a 3-week ramp-up phase, a 3-week optimal phase, and a 2-week decreasing phase. No differences were observed between the groups in terms of weekly initial and final liveweight, average daily gain, or predicted dry matter intake. However, during the optimal and decreasing phases, average enteric CH4 emissions were significantly (P < 0.05) reduced in steers that received Brominata supplementation compared to the Control (115 vs. 185 g/d, respectively). CO2 emissions were similar between the two groups (6.8 vs. 7.2 kg/d), while H2 emissions were lower (P < 0.05) in the control group (3.4 vs. 1.8 g/d). The findings suggest that pelleted bromoform-containing feed additive has the potential to reduce enteric CH4 emissions from grazing beef cattle. The observed 37.7% average reduction in CH₄ production, achieved without compromising animal performance, suggests a promising approach for mitigating the environmental impact of livestock farming.