scholarly journals Is there a relationship between genetic merit and enteric methane emission rate of lactating Holstein-Friesian dairy cows?

animal ◽  
2015 ◽  
Vol 9 (11) ◽  
pp. 1807-1812 ◽  
Author(s):  
L.F. Dong ◽  
T. Yan ◽  
C.P. Ferris ◽  
D.A. McDowell ◽  
A. Gordon
Keyword(s):  
Dairy Cows ◽  
Methane Emission ◽  
Emission Rate ◽  
Genetic Merit ◽  
Holstein Friesian ◽  
Enteric Methane ◽  
Methane Emission Rate

Physiological characteristics of high genetic merit and low genetic merit dairy cows: a comparison

1998 ◽  
Vol 1998 ◽  
pp. 4-4
Author(s):  
A. Sorensen ◽  
M. Alamer ◽  
C. H. Knight
Keyword(s):  
Dairy Cows ◽  
Research Effort ◽  
Genetic Selection ◽  
Plasma Samples ◽  
Major Research ◽  
Genetic Merit ◽  
Casting Technique ◽  
Biological Variables ◽  
Holstein Friesian ◽  
Key Enzyme

Genetic selection has greatly improved individual cow productivity. A high genetic merit Holstein Friesian cow will produce 10,000 of litres of milk in a 305 day lactation, those of lower genetic merit half this amount. Despite major research effort in generating these differences, quantitative biological description of what has been achieved is lacking. The aim of this study was to compare biological variables of relevance to milk synthesis in well defined high genetic merit and lower genetic merit dairy cows.12 cows of high genetic merit (HGM: top 5% of UK national herd) and 12 of lower genetic merit (LGM: close to UK average) were purchased from the Blythbank and Langhill herds; the ontogeny of these selection lines has been described elsewhere (Woolliams et al, 1993). Mean parity was 3.7±0.3 and was balanced between HGM and LGM. Management of the two groups was identical. Measurements were made over a period of two weeks close to peak lactation. Milk yield was recorded at each milking. Plasma samples were collected and analysed for a variety of hormones by radioimmunoassay and metabolites by established spectrophotometric assays. Udder size was determined by a casting technique (Dewhurst et al., 1993) and mammary biopsies for key enzyme activities were obtained as described by Knight et. al. (1992). Differences between lines were analysed by analysis of variance (ANOVA).

Forage and Flax Seed Impact on Enteric Methane Emission in Dairy Cows

2011 ◽  
Vol 4 (1) ◽  
pp. 1-8 ◽  
Author(s):  
V. Sejian ◽  
J. Lakritz ◽  
T. Ezeji ◽  
R. Lal
Keyword(s):  
Dairy Cows ◽  
Methane Emission ◽  
Flax Seed ◽  
Enteric Methane

Physiological characteristics of high genetic merit and low genetic merit dairy cows: a comparison

1998 ◽  
Vol 1998 ◽  
pp. 4-4 ◽  
Author(s):  
A. Sorensen ◽  
M. Alamer ◽  
C. H. Knight
Keyword(s):  
Dairy Cows ◽  
Research Effort ◽  
Genetic Selection ◽  
Plasma Samples ◽  
Major Research ◽  
Genetic Merit ◽  
Casting Technique ◽  
Biological Variables ◽  
Holstein Friesian ◽  
Key Enzyme

Genetic selection has greatly improved individual cow productivity. A high genetic merit Holstein Friesian cow will produce 10,000 of litres of milk in a 305 day lactation, those of lower genetic merit half this amount. Despite major research effort in generating these differences, quantitative biological description of what has been achieved is lacking. The aim of this study was to compare biological variables of relevance to milk synthesis in well defined high genetic merit and lower genetic merit dairy cows.12 cows of high genetic merit (HGM: top 5% of UK national herd) and 12 of lower genetic merit (LGM: close to UK average) were purchased from the Blythbank and Langhill herds; the ontogeny of these selection lines has been described elsewhere (Woolliams et al, 1993). Mean parity was 3.7±0.3 and was balanced between HGM and LGM. Management of the two groups was identical. Measurements were made over a period of two weeks close to peak lactation. Milk yield was recorded at each milking. Plasma samples were collected and analysed for a variety of hormones by radioimmunoassay and metabolites by established spectrophotometric assays. Udder size was determined by a casting technique (Dewhurst et al., 1993) and mammary biopsies for key enzyme activities were obtained as described by Knight et. al. (1992). Differences between lines were analysed by analysis of variance (ANOVA).

The influence of cow genetic merit for milk production on response to level of concentrate supplementation in a grass based system

2003 ◽  
Vol 2003 ◽  
pp. 57-57 ◽  
Author(s):  
P. Dillon ◽  
J. Kennedy ◽  
P. Faverdin ◽  
L. Delaby ◽  
F. Buckley ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Yield ◽  
Yield Potential ◽  
Genetic Merit ◽  
Concentrate Supplementation ◽  
Holstein Friesian

Pre-1990 published responses to supplementation at pasture ranged from 0.4 to 0.6kg milk/kg concentrate fed. However since 1990 higher responses to concentrate supplementation at pasture have been published (Delaby 2001). The objective of this study was to determine if milk production responses of Holstein-Friesian dairy cows to concentrate supplementation at pasture are influenced by genetic merit (milk yield potential) in a spring calving grass based system of milk production.

scholarly journals Comparing facility-level methane emission rate estimates at natural gas gathering and boosting stations

Elem Sci Anth ◽  
2017 ◽  
Vol 5 ◽  
Author(s):  
Timothy L. Vaughn ◽  
Clay S. Bell ◽  
Tara I. Yacovitch ◽  
Joseph R. Roscioli ◽  
Scott C. Herndon ◽  
...  
Keyword(s):  
Natural Gas ◽  
Confidence Intervals ◽  
Methane Emission ◽  
Emission Rate ◽  
National Study ◽  
Aircraft Measurements ◽  
Component Level ◽  
Facility Level ◽  
Unburned Fuel ◽  
Methane Emission Rate

Coordinated dual-tracer, aircraft-based, and direct component-level measurements were made at midstream natural gas gathering and boosting stations in the Fayetteville shale (Arkansas, USA). On-site component-level measurements were combined with engineering estimates to generate comprehensive facility-level methane emission rate estimates (“study on-site estimates (SOE)”) comparable to tracer and aircraft measurements. Combustion slip (unburned fuel entrained in compressor engine exhaust), which was calculated based on 111 recent measurements of representative compressor engines, accounts for an estimated 75% of cumulative SOEs at gathering stations included in comparisons. Measured methane emissions from regenerator vents on glycol dehydrator units were substantially larger than predicted by modelling software; the contribution of dehydrator regenerator vents to the cumulative SOE would increase from 1% to 10% if based on direct measurements. Concurrent measurements at 14 normally-operating facilities show relative agreement between tracer and SOE, but indicate that tracer measurements estimate lower emissions (regression of tracer to SOE = 0.91 (95% CI = 0.83–0.99), R2 = 0.89). Tracer and SOE 95% confidence intervals overlap at 11/14 facilities. Contemporaneous measurements at six facilities suggest that aircraft measurements estimate higher emissions than SOE. Aircraft and study on-site estimate 95% confidence intervals overlap at 3/6 facilities. The average facility level emission rate (FLER) estimated by tracer measurements in this study is 17–73% higher than a prior national study by Marchese et al.

A prediction equation for enteric methane emission from dairy cows for use in NorFor

2013 ◽  
Vol 63 (3) ◽  
pp. 126-130 ◽  
Author(s):  
N. I. Nielsen ◽  
H. Volden ◽  
M. Åkerlind ◽  
M. Brask ◽  
A. L. F. Hellwing ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Methane Emission ◽  
Prediction Equation ◽  
Enteric Methane

scholarly journals Predicting enteric methane emission of dairy cows with milk Fourier-transform infrared spectra and gas chromatography–based milk fatty acid profiles

2018 ◽  
Vol 101 (6) ◽  
pp. 5582-5598 ◽  
Author(s):  
S. van Gastelen ◽  
H. Mollenhorst ◽  
E.C. Antunes-Fernandes ◽  
K.A. Hettinga ◽  
G.G. van Burgsteden ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Fourier Transform ◽  
Fatty Acid ◽  
Dairy Cows ◽  
Infrared Spectra ◽  
Methane Emission ◽  
Fourier Transform Infrared ◽  
Milk Fatty Acid ◽  
Fatty Acid Profiles ◽  
Enteric Methane

scholarly journals Enteric methane emission, milk production, and composition of dairy cows fed 3-nitrooxypropanol

2021 ◽  
Vol 104 (1) ◽  
pp. 357-366
Author(s):  
A. Melgar ◽  
C.F.A. Lage ◽  
K. Nedelkov ◽  
S.E. Räisänen ◽  
H. Stefenoni ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Methane Emission ◽  
Enteric Methane

scholarly journals A Basic Model to Predict Enteric Methane Emission from Dairy Cows and Its Application to Update Operational Models for the National Inventory in Norway

2021 ◽  
Author(s):  
Puchun Niu ◽  
Angela Schwarm ◽  
Helge Bonesmo ◽  
Alemayehu Kidane ◽  
Bente Aspeholen Åby ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Methane Emission ◽  
Neutral Detergent Fiber ◽  
Published Data ◽  
Operational Model ◽  
National Inventory ◽  
Basic Model ◽  
Ch4 Production ◽  
Wide Range ◽  
Enteric Methane

The aim of this study was to develop a basic model to predict enteric methane emission from dairy cows and to update operational calculations for the national inventory in Norway. Basic models were developed using a database with 63 treatment means from 19 studies. The database included records for enteric CH4 production (MJ/day), dry matter intake (DMI), and dietary nutrient composition. The basic models were evaluated against an external database (n=36, from ten studies) along with other extant models. When evaluated by low root mean square prediction errors and high concordance correlation coefficients, the developed basic models that included DMI, dietary concentrations of fatty acids and neutral detergent fiber performed slightly better in predicting CH4 emissions than extant models. In order to propose country-specific values for the CH4 conversion factor Ym (% of gross energy intake partitioned into CH4) and thus to carry out the national inventory for Norway, the existing operational model was updated for the prediction of Ym over a wide range of feeding situations using energy corrected milk and dietary concentrate share as predictor variables. Input values of Ym were updated based on the results from the basic models. The predicted Ym ranged from 6.22 to 6.72%. In conclusion, the prediction of CH4 production from dairy cows was improved with the help of newly published data, which enabled an update of the operational model for calculating the national inventory of CH4 in Norway.

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