scholarly journals Investigation of intra-day variability of gaseous measurements in sheep using Portable accumulation chambers 1

2021 ◽  
Author(s):  
E O’ Connor ◽  
N McHugh ◽  
T M Boland ◽  
E Dunne ◽  
F M McGovern
Keyword(s):  
Small Ruminants ◽  
Live Weight ◽  
Optimal Time ◽  
Body Volume ◽  
Gaseous Emissions ◽  
O2 Consumption ◽  
Time Points ◽  
Ch4 Production ◽  
Measurement Protocol ◽  
Carbon Dioxide Co2

Abstract Portable accumulation chambers (PAC) enable short term spot measurements of gaseous emissions including methane (CH4), carbon dioxide (CO2) and oxygen (O2) consumption from small ruminants. To date the differences in morning and evening gaseous measurements in the PAC have not been investigated. The objectives of this study were to investigate: 1) the optimal measurement time in the PAC, 2) the appropriate method of accounting for the animal’s size when calculating the animal’s gaseous output, and 3) the intra-day variability of gaseous measurements. A total of 12 ewe lambs (c. 10 to 11 months of age) were randomly selected each day from a cohort of 48 animals over nine consecutive days. Methane emissions from the 12 lambs were measured in 12 PAC during two measurement runs daily, AM (8 to 10 h) and PM (14 to 16 h). Animals were removed from Perennial ryegrass silage for at least 1 hour prior to measurements in the PAC and animals were assigned randomly to each of the 12 chambers. Methane (ppm) concentration, O2 and CO2 percentage were measured at 5 time points (T1 = 0.0 min, T2 = 12.5 min, T3 = 25.0 min, T4 = 37.5 min and T5 = 50.0 min from entry of the first animal into the first chamber) using an Eagle 2 monitor. The correlation between time points T5-T1 (i.e. 50 min minus 0 min after entry of the animal to the chamber) and T4-T1 was 0.95, 0.92 and 0.77 for CH4, O2 and CO2, respectively (P<0.01). The correlation between CH4 and CO2 output and O2 consumption, calculated with live-weight and with body volume was 0.99 (P<0.001). The correlation between the PAC measurement recorded on the same animal in the AM and PM measurement runs was 0.73. Factors associated with CH4 production included: day and time of measurement, the live-weight of the animal and the hourly relative humidity. Results from this study suggest that the optimal time for measuring an animal’s gaseous output in the PAC is 50 min, that live-weight should be used in the calculation of gaseous output from an animal and that the measurement of an animal’s gaseous emissions in either the AM or PM does not impact on the ranking of animals when gaseous emissions are measured using the feeding and measurement protocol outlined in the present study.

scholarly journals Repeatability of gaseous measurements across consecutive days in sheep using Portable accumulation chambers

2021 ◽  
Author(s):  
E O’ Connor ◽  
F M McGovern ◽  
D T Byrne ◽  
T M Boland ◽  
E Dunne ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Small Ruminants ◽  
Prediction Equation ◽  
Gaseous Emissions ◽  
Time Points ◽  
Ewe Lambs ◽  
Carbon Dioxide Co2 ◽  
High Level

Abstract Portable accumulation chambers (PAC) enable gaseous emissions from small ruminants to be measured over a 50 min period, to date however, the repeatability of consecutive days of measurement in the PAC has not been investigated. The objectives of this study were to investigate: 1) the repeatability of consecutive days of gaseous measurements in the PAC, 2) the number of days required to achieve precise gaseous measurements, and 3) to develop a prediction equation for gaseous emissions in sheep. A total of 48 ewe lambs (c. 10 to 11 mo of age) were randomly divided into four measurement groups each day, for 17 consecutive days. Gaseous measurements were conducted between 0800 h and 1200 h daily. Animals were removed from perennial ryegrass silage for at least 1 h before measurements in the PAC and animals were assigned randomly to each of the 12 chambers. Methane (CH4; ppm) concentration, oxygen (O2; percentage) and carbon dioxide (CO2; percentage) were measured at 3 time points (0, 25, and 50 min after entry of the first animal into the first chamber). To quantify the effect of animal and day variation on gaseous emissions, between-animal, between-day and error variances were calculated for each gaseous measurement using a linear mixed model. The number of days required to gain a certain precision (defined as the 95% confidence interval (CI) range) for each gaseous measurement was also calculated. For all 3 gases the between-day variance (39% to 40%) accounted for a larger proportion of total variance compared to between-animal variance, while the repeatability of 17 consecutive days of measurement was 0.36, 0.31 and 0.23 for CH4, CO2 and O2, respectively. Correlations between consecutive days of measurement were strong for all 3 gases; the strongest correlation between d 1 and the remaining days for CH4, CO2 and O2 was 0.71 (d 1 and d 6), 0.77 (d 1 and d 2) and 0.83 (d 1 and d 5), respectively. A high level of precision was achieved when gaseous measurements from PAC were taken over 3 consecutive days. The prediction equation over-estimated gaseous production for all 3 gases: the correlations between actual and predicted gaseous output ranged from 0.67 to 0.71, with the r 2 ranging from 0.45 to 0.71. Results from this study will aid the refinement of the protocol for the measurement of gaseous emissions in sheep using the PAC.

scholarly journals Strategies for Reducing Methane Emissions from Ruminants (Estratégias para a Redução da Emissão de Metano por Ruminantes)

2012 ◽  
Vol 4 (6) ◽  
pp. 1315
Author(s):  
Carlos E. Lascano ◽  
Juan E. Carulla ◽  
Juan De Jesus Vargas
Keyword(s):  
Production Systems ◽  
Global Climate ◽  
Small Ruminants ◽  
Live Weight ◽  
Feed Conversion ◽  
Enteric Fermentation ◽  
Ch4 Emissions ◽  
Animal Product ◽  
Ch4 Production ◽  
Grazing System

Há fortes evidências que as atividades humanas estão afetando o clima global por meio da produção de Gases de Efeito Estufa (GEE), dos quais o metano (CH4) tem elevado potencial de aquecimento. A fermentação entérica e o esterco dos ruminantes representam cerca de 30 a 40% do total das emissões antropogênicas de CH4. Este artigo traz um resumo de tecnologias existentes para reduzir as emissões de CH4 entéricas dos ruminantes, com ênfase à manipulação dietética e ruminal, à seleção/reprodução animal e à melhoria dos sistemas de produção. As diferenças na produção de CH4 entérica entre as espécies animais com base na anatomia do trato gastrointestinal, fisiologia digestiva, fermentação ruminal e nos hábitos de pastejo também são discutidas. A inibição da emissão de CH4 entérica é possível por meio do uso de ionóforos, ácidos orgânicos e óleos. Plantas alimentares contendo metabólitos secundários (taninos e saponinas i.e.) também podem reduzir a produção de CH4. O uso de animais reprodutores para melhorar a eficiência de conversão alimentar (menor consumo residual) pode contribuir com a redução da emissão total de CH4, além de reduzir a emissão por unidade de produto. Resultados utilizando o modelo IPCC nível II prevê que caprinos e vacas de elevada produção leiteira podem apresentar menor emissão de CH4 por unidade de produto em comparação com animais zebuínos e ovinos, enquanto os pequenos ruminantes (caprinos e ovinos) produzem menos CH4 por unidade de ganho de peso corporal (carne), em relação aos bovinos. A melhoria da qualidade das forragens e a implementação de práticas eficientes de uso das pastagens (sistema de pastejo e taxas de lotação) podem na maioria dos casos promover maior produção animal e incrementar a emissão absoluta de CH4, mas também reduzir a emissão de CH4 por unidade de produto animal. Palavras - chave: mudanças climáticas, gases do efeito estufa, bovinos, ovinos, caprinos, manipulação da dieta, manipulação ruminal, criação de animais, intensificação, modelagem.  Estratégias para a Redução da Emissão de Metano por Ruminantes  A B S T R A C T There is irrefutable evidence that human activities are affecting the global climate through the production of Green House Gases (GHG) of which methane (CH4) has a high warming potential. Enteric fermentation and manure from ruminants represent about 30 to 40% of the total anthropogenic CH4 emissions. This paper summarizes existing technologies to reduce enteric CH4 emissions in ruminants given emphasis to dietary and rumen manipulation, animal selection/ breeding and improvement of production systems. Differences in enteric CH4 production among animal species based on anatomy of the GI tract, digestive physiology, rumen fermentation and grazing habits are also discussed. Inhibition of enteric CH4 emission is possible through the use of ionophores, organic acids and oils. Feeding plants containing secondary metabolites (i.e. tannins and saponins) can reduce CH4 production. Breeding for improved feed conversion efficiency (lower residual feed intake) is likely to reduce total and per unit product CH4 emissions. Results using the IPCC Tier II model predict that goats and high producing dairy cattle can potentially produce less CH4 emissions per unit of milk than Cebu cattle or sheep, while small ruminants (goats and sheep) produce less CH4 per unit of live weight gain (meat) than cattle. The introduction of improved high quality forages and the implementation of efficient pasture utilization practices (grazing system and stocking rate) can result in most cases in improved animal production and in increased absolute CH4 emissions, but in reduced CH4 per unit of animal product. Keywords: climate change, greenhouse gases, cattle, sheep, goats, dietary manipulation, rumen manipulation, animal breeding, intensification, modelling

scholarly journals 178 Use of silvopastures and woodlands to expand the grazing opportunity for small ruminants

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 67-68
Author(s):  
Uma Karki
Keyword(s):  
Body Condition Score ◽  
Small Ruminants ◽  
Warm Season ◽  
Live Weight ◽  
Limited Resource ◽  
Ground Level ◽  
Vegetation Biomass ◽  
Meat Goats ◽  
Condition Score ◽  
And Behavior

Abstract Pasture-based small-ruminant farming is a popular enterprise in the Southeast, especially for small and limited-resource producers. Although woodlands occupy a majority of the land cover in the South and can be a promising resource for raising small ruminants, not much attention has been given on using such resources. A series of studies were conducted at the facilities of Tuskegee University with the overall objective of exploring the potential of using silvopastures and woodlands for raising small ruminants. Grazing studies were conducted from 2015 to 2019 using meat goats and hair sheep in silvopastures and woodland plots. Silvopastures were developed by thinning down the existing woodlands and planting suitable cool- and warm-season forages. Grazing facilities were installed in the study plots and animals were rotationally stocked each year during both cool- and warm-season grazing periods. In 2017, non-pine plants in woodlands were cut to three different heights (ground level and 0.9 m and 1.5 m from the ground level) or left uncut (control) to see the effects on understory vegetation biomass production and utilization by small ruminants. Data on vegetation biomass and quality, canopy height, animal performance and behavior, browsing height, and vegetation preference were collected and analyzed. Small ruminants were found to utilize all planted forages (silvopastures) well and most of the understory plants in woodlands. Vegetation biomass in woodlands increased in areas where non-pine plants were cut versus the control (36–106%; P < 0.0001). Mature animals maintained a desirable body condition score (≥2.6) and FAMACHA score (≤2.6) in woodlands. However, young, growing animals showed a poor live weight gain, especially during some portion of the study. Animals performed well when they were stocked in silvopastures. Both species showed a similar preference for most plant species available in woodlands. Results show a tremendous potential of using silvopastures and woodlands for expanding the grazing opportunity for small ruminants. However, the provision of some supplements would be necessary while stocking young animals in woodlands.

scholarly journals Methane and nitrous oxide sources and emissions in a subtropical freshwater reservoir, South East Queensland, Australia

2014 ◽  
Vol 11 (18) ◽  
pp. 5245-5258 ◽  
Author(s):  
K. Sturm ◽  
Z. Yuan ◽  
B. Gibbes ◽  
U. Werner ◽  
A. Grinham
Keyword(s):  
Nitrous Oxide ◽  
Water Column ◽  
Water Flux ◽  
No Production ◽  
Pore Waters ◽  
Ch4 Production ◽  
N2o Fluxes ◽  
Ch4 And N2o ◽  
Diffusive Fluxes ◽  
Carbon Dioxide Co2

Abstract. Reservoirs have been identified as an important source of non-carbon dioxide (CO2) greenhouse gases with wide ranging fluxes for reported methane (CH4); however, fluxes for nitrous oxide (N2O) are rarely quantified. This study investigates CH4 and N2O sources and emissions in a subtropical freshwater Gold Creek Reservoir, Australia, using a combination of water–air and sediment–water flux measurements and water column and pore water analyses. The reservoir was clearly a source of these gases as surface waters were supersaturated with CH4 and N2O. Atmospheric CH4 fluxes were dominated by ebullition (60 to 99%) relative to diffusive fluxes and ranged from 4.14 × 102 to 3.06 × 105 μmol CH4 m−2 day−1 across the sampling sites. Dissolved CH4 concentrations were highest in the anoxic water column and sediment pore waters (approximately 5 000 000% supersaturated). CH4 production rates of up to 3616 ± 395 μmol CH4 m−2 day−1 were found during sediment incubations in anoxic conditions. These findings are in contrast to N2O where no production was detected during sediment incubations and the highest dissolved N2O concentrations were found in the oxic water column which was 110 to 220% supersaturated with N2O. N2O fluxes to the atmosphere were primarily through the diffusive pathway, mainly driven by diffusive fluxes from the water column and by a minor contribution from sediment diffusion and ebullition. Results suggest that future studies of subtropical reservoirs should monitor CH4 fluxes with an appropriate spatial resolution to ensure capture of ebullition zones, whereas assessment of N2O fluxes should focus on the diffusive pathway.

scholarly journals Genomic predictions for enteric methane production are improved by metabolome and microbiome data in sheep (Ovis aries)

2020 ◽  
Vol 98 (10) ◽  
Author(s):  
Elizabeth M Ross ◽  
Ben J Hayes ◽  
David Tucker ◽  
Jude Bond ◽  
Stuart E Denman ◽  
...  
Keyword(s):  
Methane Production ◽  
Prediction Accuracy ◽  
Live Weight ◽  
Ovis Aries ◽  
Prediction Algorithm ◽  
Genomic Relationship ◽  
Time Points ◽  
Genomic Relationships ◽  
Genomic Predictions ◽  
Time Point

Abstract Methane production from rumen methanogenesis contributes approximately 71% of greenhouse gas emissions from the agricultural sector. This study has performed genomic predictions for methane production from 99 sheep across 3 yr using a residual methane phenotype that is log methane yield corrected for live weight, rumen volume, and feed intake. Using genomic relationships, the prediction accuracies (as determined by the correlation between predicted and observed residual methane production) ranged from 0.058 to 0.220 depending on the time point being predicted. The best linear unbiased prediction algorithm was then applied to relationships between animals that were built on the rumen metabolome and microbiome. Prediction accuracies for the metabolome-based relationships for the two available time points were 0.254 and 0.132; the prediction accuracy for the first microbiome time point was 0.142. The second microbiome time point could not successfully predict residual methane production. When the metabolomic relationships were added to the genomic relationships, the accuracy of predictions increased to 0.274 (from 0.201 when only the genomic relationship was used) and 0.158 (from 0.081 when only the genomic relationship was used) for the two time points, respectively. When the microbiome relationships from the first time point were added to the genomic relationships, the maximum prediction accuracy increased to 0.247 (from 0.216 when only the genomic relationship was used), which was achieved by giving the genomic relationships 10 times more weighting than the microbiome relationships. These accuracies were higher than the genomic, metabolomic, and microbiome relationship matrixes achieved alone when identical sets of animals were used.

Gaseous emissions of slurry from pigs offered low crude protein diets

1996 ◽  
Vol 1996 ◽  
pp. 57-57
Author(s):  
P.J. Hobbs ◽  
B.F. Pain ◽  
T.H. Misselbrook ◽  
R.M. Kay ◽  
P.A. Lee
Keyword(s):  
Crude Protein ◽  
Nitrogen Concentration ◽  
Live Weight ◽  
Livestock Production ◽  
Nitrogen Excretion ◽  
Emission Characteristics ◽  
Gaseous Emissions ◽  
Air Samples ◽  
Odour Concentration ◽  
Protein Diets

Increasingly emissions from livestock production has caused problems for the industry. If the problem can be reduced at source by a change of diet this could be the simplest solution, requiring the minimum of effort.Reducing nitrogen excretion by pigs offered low crude protein (CP) diets may not only reduce nitrogen polluting potential of slurry, but also change gaseous and odorous emission characteristics.Slurry was collected from beneath slatted pens at the end of the fmishing period (65 to 90 kg live weight) of groups of pigs offered either a commercially available finisher diet (F-com), slurry A, or a low CP diet (F-lc) formulated using a commercial least cost database which has been shown to reduce the nitrogen concentration of the slurry, slurry B. Slurry samples were placed in a closed odour emission chamber and air samples taken after 0, 15, 40, 65, 95, 155 and 225 minutes. Odour concentration (OC) was determined by dynamic dilution olfactometry.

scholarly journals Carbon exchange between the atmosphere and subtropical forested cypress and pine wetlands

2014 ◽  
Vol 11 (11) ◽  
pp. 15753-15791
Author(s):  
W. B. Shoemaker ◽  
J. G. Barr ◽  
D. B. Botkin ◽  
S. L. Graham
Keyword(s):  
Carbon Dioxide ◽  
Methane Emission ◽  
Vegetation Index ◽  
Overland Flow ◽  
Net Ecosystem Exchange ◽  
Forested Wetland ◽  
Carbon Dioxide Exchange ◽  
Cypress Swamp ◽  
Ch4 Production ◽  
Carbon Dioxide Co2

Abstract. Carbon dioxide exchange between the atmosphere and forested subtropical wetlands is largely unknown. Here we report a first step in characterizing this atmospheric–ecosystem carbon (C) exchange, for cypress strands and pine forests in the Greater Everglades of Florida as measured with eddy covariance methods at three locations (Cypress Swamp, Dwarf Cypress and Pine Upland) for one year. Links between water and C cycles are examined at these three sites, and methane emission measured only at the Dwarf Cypress site. Each forested wetland showed net C uptake (retained in the soil and biomass or transported laterally via overland flow) from the atmosphere monthly and annually. Net ecosystem exchange (NEE) of carbon dioxide (CO2) (difference between photosynthesis and respiration, with negative values representing net ecosystem uptake) was greatest at the Cypress Swamp (−1000 g C m-2 year-1), moderate at the Pine Upland (−900 g C m-2 year-1), and least at the Dwarf Cypress (−500 g C m-2 year-1). Methane emission was a negligible part of the C (12 g C m-2 year-1) budget when compared to NEE. However, methane (CH4) production was considerable in terms of global warming potential, as about 20 g CH4 emitted per m2 year was equivalent to about 500 g CO2 emitted per m2 year}. Changes in NEE were clearly a function of seasonality in solar insolation, air temperature and water availability from rainfall. We also note that changes in the satellite-derived enhanced-vegetation index (EVI) served as a useful surrogate for changes in net and gross atmospheric–ecosystem C exchange at these forested wetland sites.

scholarly journals Greenhouse gas production in degrading ice-rich permafrost deposits in northeast Siberia

2018 ◽  
Author(s):  
Josefine Walz ◽  
Christian Knoblauch ◽  
Ronja Tigges ◽  
Thomas Opel ◽  
Lutz Schirrmeister ◽  
...  
Keyword(s):  
Greenhouse Gases ◽  
Greenhouse Gas ◽  
Late Glacial ◽  
Gas Production ◽  
Depositional Environments ◽  
Co2 Production ◽  
Glacial Deposits ◽  
Ch4 Production ◽  
Carbon Dioxide Co2

Abstract. Permafrost deposits have been a sink for atmospheric carbon for millennia. Thaw-erosional processes, however, can lead to rapid degradation of ice-rich permafrost and the release of substantial amounts of organic carbon (OC). The amount of the OC stored in these deposits and their potential to be microbially decomposed to the greenhouse gases carbon dioxide (CO2) and methane (CH4) depends on climatic and environmental conditions during deposition and the decomposition history before incorporation into the permafrost. Here, we examine potential greenhouse gas production in degrading ice-rich permafrost deposits from three locations in the northeast Siberian Laptev Sea region. The deposits span a period of about 55 kyr and include deposits from the last glacial and Holocene interglacial periods. Samples from all three locations were aerobically and anaerobically incubated for 134 days at 4 °C. Greenhouse gas production was generally higher in glacial than Holocene deposits. In permafrost deposits from the Holocene and the late glacial transition, only 0.1–4.0 % of the initially available OC could be decomposed to CO2, while 0.2–6.1 % could be decomposed in glacial deposits. Within the glacial deposits from the Kargin interstadial period (Marine Isotope Stage 3), local depositional environments, especially soil moisture, also affected the preservation of OC. Sediments deposited under wet conditions contained more labile OC and thus produced more greenhouse gases than sediments deposited under drier conditions. To assess the long-term production potentials, deposits from two locations were incubated for a total of 785 days. However, more than 50 % of the aerobically produced and more than 80 % of anaerobically produced CO2 after 785 days of incubation were already produced within the first 134 days, highlighting the quantitative importance of the slowly decomposing OC pool in permafrost. CH4 production was generally observed in active layer samples but only sporadically in permafrost samples and was several orders of magnitude smaller than CO2 production.

scholarly journals Reproductive Qualities of Romanov Sheep with Regard to the Paratypic Factors

2019 ◽  
Vol 9 (1) ◽  
pp. 3897-3901
Keyword(s):  
Best Practices ◽  
Live Weight ◽  
Optimal Time ◽  
Reproductive Ability ◽  
Early Maturing ◽  
Tver Region ◽  
Autumn And Winter ◽  
Pedigree Breeding ◽  
Birth Type

The article discusses the results of own studies of the authors, the literature data, and the best practices of Romanov sheep breeding. The research was performed at the two Romanov sheep pedigree breeding units in the Tver region, LLC Rassvet and LLC PF Pokrov. This breed has several advantages, such as the possibility of insemination in any season, early maturing, multiparity, the quality of sheepskin, and the taste of the lamb meat. The authors studied the productivity and the reproductive ability of ewes depending on the season, the age of insemination, the live weight, the birth type of the lamb crop. More lambs are obtained in the lambings during the autumn and winter from the ewes after three and more lambings. The survival rate is higher in the winter and summer lambings. The optimal time of insemination is 12 – 13 months. At these farms, three lambings were obtained in two years.

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