Within- and between-animal variance in methane emissions in non-lactating dairy cows

2008 ◽  
Vol 48 (2) ◽  
pp. 124 ◽  
Author(s):  
J. B. Vlaming ◽  
N. Lopez-Villalobos ◽  
I. M. Brookes ◽  
S. O. Hoskin ◽  
H. Clark
Keyword(s):  
Sulfur Hexafluoride ◽  
Energy Levels ◽  
Tracer Technique ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
Lactating Dairy Cows ◽  
Coefficients Of Variation ◽  
Lactating Dairy Cattle ◽  
Over Time

Several studies on methane (CH4) emissions have focussed on selecting high and low CH4-emitting animals. One challenge faced by this work is the lack of consistency, or repeatability, in animal rankings over time. Repeatability for individual animals over time needs to be high to reliably detect high and low CH4-emitting animals. A possible explanation for the lack of repeatability is a relatively high within-animal variation in daily CH4 emissions, meaning that animals could then change their ranking when compared at different points in time. An experiment was undertaken with four non-lactating dairy cattle to assess the within- and between-animal variation in CH4 emissions over time when measured using the sulfur hexafluoride (SF6) tracer technique. Two contrasting diets were fed to the cattle at maintenance energy levels: lucerne silage (diet 1) and a cereal + lucerne + straw mixed ration diet (diet 2). Daily CH4 measurements were undertaken for 23 days on diet 1 and 30 days on diet 2. There was a significant (P < 0.001) difference between diet 1 and diet 2 in daily CH4 production, with mean (±s.e.) production of 124.3 (11.1) g CH4/day from diet 1 and 169.8 (±11.0) g CH4/day from diet 2. Lower CH4 yield (g CH4/kg dry matter intake) was recorded on diet 1 (22.8 ± 2.0) than diet 2 (32.0 ± 2.0). Cows differed significantly (P < 0.05) from one another in daily CH4 yield (diet 1: cow 1 = 19.4 ± 0.6, cow 2 = 22.2 ± 0.8, cow 3 = 23.2 ± 0.7, cow 4 = 25.4 ± 0.6; diet 2: cow 1 = 26.0 ± 0.7, cow 2 = 36.4 ± 0.7, cow 3 = 29.3 ± 0.7, cow 4 = 36.6 ± 0.7). Variances for daily CH4 yield were smaller for diet 1 (within animal = 6.91, between animals = 6.23) than for diet 2 (within animal = 10.09, between animals = 27.79). Estimates of repeatability (variation between animals/total variation) for daily CH4 yield were 47 and 73% in diet 1 and 2, respectively. Coefficients of variation in average daily CH4 emissions in this experiment ranged from 8 to 18% despite the fact that each animal received the same quantity and quality of feed each day. While further research is required, the high within-animal variability in CH4 emissions measured using the SF6 tracer technique may explain why there has been difficulty in obtaining consistent rankings in CH4 yields when animals are measured on multiple occasions. The results also suggest that the SF6 tracer technique may exaggerate apparent between animal differences in CH4 emissions.

Supplementation with crushed rapeseed causes reduction of methane emissions from lactating dairy cows on pasture

2017 ◽  
Vol 57 (1) ◽  
pp. 81 ◽  
Author(s):  
T. M. Storlien ◽  
E. Prestløkken ◽  
K. A. Beauchemin ◽  
T. A. McAllister ◽  
A. Iwaasa ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Fat ◽  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Effective Means ◽  
Fat Content ◽  
Tracer Gas ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
Lactating Dairy Cows

The main objective of this study was to investigate the effect of supplementing a pasture diet with crushed rapeseed on enteric methane (CH4) emissions from lactating dairy cows. The experiment was conducted as a crossover design using eight multiparous lactating Norwegian red dairy cows [(means ± s.d.) 548 ± 52 kg bodyweight, 38 ± 14 days in milk and 35 ± 3.7 kg milk/day, at the start of the experiment] maintained in two groups and fed two diets in two periods with the second period extended (18 days) to investigate the persistence of the CH4 response. Four of the eight cows were fitted with a rumen cannula with two cannulated cows assigned to each group. Cows were maintained on pasture (24 h/day) with access to 9 kg/day of concentrate containing 10% crushed rapeseed (RSC) or a control concentrate (CC). Dietary fat content was 63 g/kg dry matter for RSC and 42 g/kg dry matter for CC. The CH4 production was measured for five consecutive days in each period using the sulfur hexafluoride tracer gas technique. Compared with CC, RSC caused a reduction in enteric CH4 emission (221 vs 251 g/day and 8.1 vs 9.0 g/kg of energy-corrected milk), and this response persisted in the extension period. Cows fed RSC had higher milk yield compared with cows fed CC (31.7 vs 29.6 kg/day). However, milk fat and protein content were lower in milk from cows fed RSC than CC. Therefore, energy-corrected milk was not affected by treatment. Feeding RSC lowered milk fat content of palmitic acid compared with CC. The study showed that adding crushed RSC to the diet can be an effective means of reducing CH4 emissions from lactating dairy cows on pasture, without negatively affecting milk production.

Methane emissions from young and mature dairy cattle

2016 ◽  
Vol 56 (11) ◽  
pp. 1897 ◽  
Author(s):  
C. A. Ramírez-Restrepo ◽  
H. Clark ◽  
S. Muetzel
Keyword(s):  
New Zealand ◽  
Emission Factor ◽  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Dry Matter Intake ◽  
Tracer Technique ◽  
Ch4 Emissions ◽  
Dairy Heifers ◽  
Age Related ◽  
The Mean

Daily methane (CH4) emissions (g) and CH4 yield (g/kg dry matter intake) were measured from 10 dairy heifers (<1 year old) and nine rumen-fistulated cows (>6 years old) fed ryegrass (Lolium perenne) chaffage indoors. The CH4 emissions were estimated using the sulfur hexafluoride tracer technique in four ~5-day periods beginning in June 2008 and repeated 4, 6 and 7 months later. Respiratory chambers were used in four ~13-day periods beginning in November 2008 and repeated 2, 5 and 6 months later. Third and fourth sulfur hexafluoride tracer periods overlapped with the first and second chamber measurement periods, respectively. Averaged over the four measurement periods the CH4 yields determined using both techniques were similar for heifers and cows. The mean CH4 yield estimated by the sulfur hexafluoride tracer technique was 25.3 ± 0.52 for heifers and 24.1 ± 0.55 for mature cows, whereas the mean CH4 yield measured in respiratory chambers was 23.7 ± 0.66 for heifers and 23.6 ± 0.66 for mature cows. Averaged over the eight measurements irrespective of technique, CH4 yields for heifers (24.5 ± 0.42) and cows (23.8 ± 0.43) were similar. There was also no difference between CH4 methods for assessing CH4 yield during the overlapping measurement periods. It was concluded that no consistent differences in CH4 yield existed between heifers and mature cows. Therefore, we do not recommend adoption of an age-related emission factor for cattle in the national inventory calculations for New Zealand.

Repeatability of enteric methane determinations from cattle using either the SF6 tracer technique or the GreenFeed system

2016 ◽  
Vol 56 (3) ◽  
pp. 238 ◽  
Author(s):  
M. Arbre ◽  
Y. Rochette ◽  
J. Guyader ◽  
C. Lascoux ◽  
L. M. Gómez ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Tracer Technique ◽  
Short Term ◽  
Experimental Conditions ◽  
Ch4 Emissions ◽  
Lactating Dairy Cows ◽  
Significant Difference ◽  
Enteric Methane ◽  
Expired Gas ◽  
Measurement Period

The SF6 tracer technique (SF6) and GreenFeed system (GF) are two methods for measuring enteric methane (CH4) emissions from cattle. Both methods estimate individual daily CH4 emissions from expired gas samples collected either continuously over 24 h in a canister (SF6) or several times a day during short-term periods (3–8 min) when cattle visit an automated head chamber (GF). The objective of this work was to study repeatability (R) of each method according to duration of measurement period as an indicator of their precision. The R of CH4 measurements was evaluated in two different trials using cows. For Experiment 1, the SF6 technique was used for 20 days in six non-lactating dairy cows fed a hay-based diet; for Experiment 2, the GF system was used for 91 days in seven lactating dairy cows fed a maize silage-based diet. The CH4 data were grouped by periods of 1–10 days (SF6) and 1–45 days (GF). The CH4 emissions averaged 23.6 ± 3.9 g/kg dry matter intake (DMI) for the SF6 and 17.4 ± 3.3 g/kg DMI for the GF on the measurement period. To achieve an R value of 0.70 for CH4 emissions (g/kg DMI), 3-day periods were necessary for SF6 and 17-day periods for GF. The R did not increase after 4-day periods for SF6 (R = 0.73), but increased for GF until 45-day periods (R = 0.90). In our experimental conditions and R = 0.70, the total number of cows necessary to detect a significant difference in CH4 emissions (g/kg DMI) between two treatments (e.g. diet) was similar for SF6 and GF.

Methane emissions from weaned lambs measured at 13, 17, 25 and 35 weeks of age compared with mature ewes consuming a fresh forage diet

2008 ◽  
Vol 48 (2) ◽  
pp. 240 ◽  
Author(s):  
T. W. Knight ◽  
G. Molano ◽  
H. Clark ◽  
A. Cavanagh
Keyword(s):  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Methane Emissions ◽  
The Other ◽  
Dry Matter Intake ◽  
Ch4 Emission ◽  
Tracer Technique ◽  
Ch4 Emissions ◽  
The Mean ◽  
Measurement Period

Daily methane (CH4) emissions and dry matter intake (DMI) were measured on 14 mature ewes (3–4 years old) and 13 lambs when the lambs were 13, 17, 25 and 35 weeks of age. During the four CH4 measurement periods, all animals were kept in individual metabolism cages and fed pasture cut daily and fed at 1.5 times maintenance. Feed was offered in equal amounts at 0800 and 1500 hours daily. Methane emissions were measured using the sulfur hexafluoride tracer technique and values reported were the mean of measurement on 4–5 days for each animal. In the intervals between CH4 measurements, ewes and lambs grazed separate paddocks containing predominantly ryegrass. Daily CH4 emissions for the ewes ranged from 21.5 to 22.5 ± 1.50 g/day and were significantly higher than those of the lambs which ranged from 10.7 to 17.5 ± 1.50 g/day. Averaged across all four periods, the overall mean CH4 emission for lambs was 8% lower (P < 0.05) than for ewes (21.9 v. 23.8 ± 0.95 g CH4/kg DMI). However, within each measurement period, the emissions of CH4/kg DMI from lambs was significantly lower (P < 0.05) than those of ewes only in the fourth period when the lambs were 35 weeks of age (17.9 v. 21.9 g/kg DMI for lambs and ewes, respectively). The pasture offered to both ewes and lambs in this period was of higher quality than in the other periods (organic matter digestibility of 80% DM v. 68–71% DM at other times) and CH4 emission per kg DMI was lower in both groups of animals than in the other periods. This study supports the hypothesis that young sheep have lower CH4 emissions per unit of intake than mature animals. However, the age at which the lambs produced similar CH4/kg DMI to adult sheep could not be determined precisely because of the changes in pasture quality between different measurement periods.

Methane emissions from dairy cattle divergently selected for bloat susceptibility

2008 ◽  
Vol 48 (2) ◽  
pp. 234 ◽  
Author(s):  
C. S. Pinares-Patiño ◽  
G. Molano ◽  
A. Smith ◽  
H. Clark
Keyword(s):  
Titanium Dioxide ◽  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Methane Emissions ◽  
Dry Matter Intake ◽  
Tracer Technique ◽  
Ch4 Emissions ◽  
The Mean ◽  
Female Cattle ◽  
Mixed Age

Bloat susceptibility is a genetically inherited trait and this study explored whether cattle divergently selected for this trait (low or high bloat susceptibility) also differ in methane (CH4) emissions. Twelve low bloat (402 ± 12 kg liveweight, LW) and 12 high bloat (334 ± 13 kg LW) Friesian × Jersey mixed age (2–4 years old) non-lactating and non-pregnant female cattle were used in a late autumn (June) grazing experiment involving two periods (P1 and P2). Methane emissions were measured during 5 (P1) or 4 (P2) consecutive days using the sulfur hexafluoride (SF6) tracer technique. In P1 only, titanium dioxide (TiO2) was used for faecal output and feed dry matter intake (DMI) estimations and it was found that the selection lines did not differ in DMI per unit of LW (17.3 ± 1.3 v. 15.4 ± 1.3 g DMI/kg LW, P > 0.05; for low and high bloat cows, respectively). In both periods, the mean absolute CH4 emissions from low bloat cows were significantly higher (P < 0.001) than from high bloat cows (144.5 ± 6.3 v. 107.4 ± 7.2 and 147.9 ± 4.6 v. 119.6 ± 6.5 g/day for P1 and P2, respectively), but on per unit of LW basis, CH4 emissions from low and high bloat animals were not different from each other (P > 0.05) either at P1 (346 ± 16 v. 312 ± 11 mg/kg LW) or P2 (345 ± 11 v. 347 ± 10 mg/kg LW). In P1, when DMI was estimated using TiO2, the selection lines did not differ (P > 0.05) in CH4 yields per unit of intake (20.6 ± 0.8 v. 21.3 ± 1.4 g/kg DMI for low and high bloat, respectively). Previous studies with the same herd showed that the selection lines did not differ in DMI per unit of LW, which was confirmed by the present study from estimations of DMI by TiO2 dosing in P1. It is concluded that low and high bloat susceptible genotypes did not differ in their CH4 yields per unit of feed intake.

scholarly journals Pendugaan Emisi Metana pada Sistem Pengelolaan Tanaman Padi di Kabupaten Minahasa (The Estimation of Methane Emission in The Rice Management System in Minahasa Rregency)

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Susan Marlein Mambu
Keyword(s):  
Methane Emission ◽  
Rice Fields ◽  
Soil Types ◽  
Wetland Rice ◽  
Calculation Formula ◽  
Ch4 Emission ◽  
Irrigated Rice ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
Over Time

AbstrakPemanasan bumi secara global karena emisi gas rumah kaca ke atmosfir yang disebabkan oleh kegiatan manusia, cenderung mengalami peningkatan dari waktu ke waktu. Pertanian padi sawah, khususnya sawah teririgasi juga merupakan penyumbang terbesar gas metana ke atmosfer. Oleh karena itu, perlu adanya upaya pengurangan emisi CH4 dari kegiatan budidaya tanaman padi sawah. Penelitian dilakukan untuk mengetahui emisi CH4 dari budidaya padi sawah di kabupaten Minahasa, dengan melakukan estimasi emisi CH4 menggunakan model perhitungan formula untuk estimasi emisi CH4 pada padi sawah. Hasil penelitian ini memberikan informasi keberadaan CH4 dan jumlah produksi emisi CH4 dari lahan padi sawah di Kabupaten Minahasa, yang cenderung mengalami peningkatan dari tahun ke tahun (data tahun 2002 – 2010). Peningkatan emisi CH4 dari lahan padi sawah di Kabupaten Minahasa disebabkan oleh beberapa faktor yaitu luas panen, jenis tanah, jenis varietas, jenis pengairan dan kegiatan budidaya lainnya seperti pemupukan dan pemberian bahan organik (jerami).Kata kunci: emisi metana, padi sawahAbstractGlobal warming from greenhouse gas emissions to the atmosphere that is caused by human activities tends to be increased over time. Fields of wetland rice, particularly irrigated rice, are also the largest contributor to methane gas to the atmosphere. Therefore, CH4 emissions should be reduced from paddy rice cultivation. This research aimed to measure the production of CH4 emission in the wetland rice fields of Minahasa, using a model calculation formula to estimate CH4 emissions in the rice fields. The results informed the existence and the amount of CH4 production resulted from wetland rice fields in Minahasa, which tended to be increased from year to year (data of year 2002 to 2010). The increment of CH4 emission from wetland rice fields in Minahasa was caused by several factors, i.e. the harvested area, soil types, types of variety, types of irrigation and other cultivation activities such as fertilization and providing organic material (straw).Keywords: methane emission, wetland rice

The effect of level of intake and forage quality on methane production by sheep

2008 ◽  
Vol 48 (2) ◽  
pp. 219 ◽  
Author(s):  
G. Molano ◽  
H. Clark
Keyword(s):  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Mean Values ◽  
Ch4 Emissions ◽  
Highly Correlated ◽  
Dietary Treatments ◽  
Two Stages ◽  
Vegetative Phases

In an experiment to determine the effect of level and quality of forage intake on methane (CH4) emissions, 16 wether lambs were allocated over two periods to two dietary treatments consisting of ryegrass at two stages of physiological maturity: an advanced stage of flowering and seeding (reproductive phase) and before flowering (vegetative phase). Additionally, in each period the lambs were divided into four groups and fed differing levels of food, from three-quarters maintenance to twice maintenance, to ensure a range of dry matter intakes amongst lambs. Apparent in vivo digestibility was measured and the mean values were 62.5% and 75.3% (s.e.d. = 0.84) for reproductive and vegetative ryegrass, respectively. Methane emissions were measured with the sulfur hexafluoride tracer technique. Daily methane emission was highly correlated with the amount of dry matter intake (DMI) (R2 = 0.83) and the regression was similar for both types of feed. Mean CH4 emissions per unit of DMI were 23.7 and 22.9 g/kg DMI (s.e.d. = 0.59) for reproductive and vegetative phases of ryegrass, respectively. The CH4 emissions per unit of DMI were not related to either level of DMI or diet quality.

scholarly journals Effect of tannin-containing hays on enteric methane emissions and nitrogen partitioning in beef cattle1

2019 ◽  
Vol 97 (8) ◽  
pp. 3286-3299 ◽  
Author(s):  
Elizabeth K Stewart ◽  
Karen A Beauchemin ◽  
Xin Dai ◽  
Jennifer W MacAdam ◽  
Rachael G Christensen ◽  
...  
Keyword(s):  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Beef Cows ◽  
Nitrogen Partitioning ◽  
Sample Collection ◽  
N Retention ◽  
Treatment Groups ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
Enteric Methane

AbstractThe objective of this study was to determine whether feeding tannin-containing hays to heifers and mature beef cows influences enteric methane (CH4) emissions and nitrogen (N) excretion relative to feeding traditional legume and grass hays. Fifteen mature beef cows (Exp. 1) and 9 yearling heifers (Exp. 2) were each randomly assigned to treatment groups in an incomplete bock design with 2 periods and 6 types of hays with 3 hays fed each period (n = 5 cows and 3 heifers per treatment). Groups were fed tannin-containing [birdsfoot trefoil (BFT), sainfoin (SAN), small burnet (SML)] or non-tannin-containing [alfalfa (ALF), cicer milkvetch (CMV), meadow bromegrass (MB)] hays. Each period consisted of 14 d of adjustment followed by 5 d of sample collection. Nine cows and 9 heifers were selected for the measurement of enteric CH4 emissions (sulfur hexafluoride tracer gas technique), and excretion of feces and urine, while dry matter intake (DMI) was measured for all animals. The concentration of condensed tannins in SAN and BFT was 2.5 ± 0.50% and 0.6 ± 0.09% of dry matter (DM), respectively, while SML contained hydrolyzable tannins (4.5 ± 0.55% of DM). Cows and heifers fed tannin-containing hays excreted less urinary urea N (g/d; P &lt; 0.001) and showed lower concentrations of blood urea N (mg/dL; P &lt; 0.001) than animals fed ALF or CMV, indicating that tannins led to a shift in route of N excretion from urine to feces. Additionally, cows fed either BFT or CMV showed the greatest percentage of retained N (P &lt; 0.001). Enteric CH4 yield (g/kg of DMI) from heifers (P = 0.089) was greatest for MB, while daily CH4 production (g/d) from heifers (P = 0.054) was least for SML. However, digestibility of crude protein was reduced for cows (P &lt; 0.001) and heifers (P &lt; 0.001) consuming SML. The results suggest that tannin-containing hays have the potential to reduce urinary urea N excretion, increase N retention, and reduce enteric CH4 emissions from beef cattle. The non-bloating tannin-free legume CMV may also reduce environmental impacts relative to ALF and MB hays by reducing N excretion in urine and increasing N retention.

Methane emissions from lactating and non-lactating dairy cows and growing cattle fed fresh pasture

2017 ◽  
Vol 57 (4) ◽  
pp. 643 ◽  
Author(s):  
Arjan Jonker ◽  
German Molano ◽  
John Koolaard ◽  
Stefan Muetzel
Keyword(s):  
Dairy Cows ◽  
Physiological State ◽  
Physiological Status ◽  
Published Data ◽  
Ch4 Emissions ◽  
Dairy Heifers ◽  
Ch4 Production ◽  
Lactating Dairy Cows ◽  
A Minor ◽  
The Relationship

Currently, a fixed methane (CH4) emission factor is used for calculating total CH4 emissions from cattle in the national greenhouse gas inventory of New Zealand, independent of diet composition, cattle class (beef, dairy) or physiological state (growing, lactating, non-lactating). The objectives of this study were to determine CH4 emissions from lactating and non-lactating dairy cows (118 dairy cows; 81 lactating and 37 non-lactating, over 10 periods) and growing dairy heifers (12 measured twice) fed 100% fresh pasture forage in respiration chambers, which in combination with the published data of beef cattle (36 measured twice) fed fresh pasture were used to determine the relationship between CH4 emissions and dry matter intake (DMI), feed quality, cattle class (dairy vs beef) and physiological state (lactating, non-lactating and growing). Before regression analysis the dominant variables (DMI, CH4) needed to be transformed using natural logarithms (Ln) to make the variation in CH4 emissions more homogeneous across the range of data (i.e. stabilise the variance). Over all periods, average DMI ranged from 3.1 to 13.9 kg/day, average CH4 production from 64 to 325 g/day and average CH4 yield from 21.4 to 26.5 g/kg DMI. The DMI alone explained 90.8% of the variation in CH4 production (LnCH4 (g/day) = 3.250 + 0.9487 × LnDMI). Regression was improved to a minor extent (<3%, with associated increased prediction error) by including physiological status, cattle class or dietary composition in the model, in addition to LnDMI, on LnCH4 production. In conclusion, DMI alone was the strongest predictor for CH4 emissions from cattle fed fresh pasture with minor but irrelevant improvements in the prediction when considering pasture quality, cattle class or physiological status.

Psychological and Cognitive Aspects of Borderline Intellectual Functioning

2017 ◽  
Vol 22 (3) ◽  
pp. 159-166 ◽  
Author(s):  
Bastianina Contena ◽  
Stefano Taddei
Keyword(s):  
Quality Of Life ◽  
Systematic Review ◽  
Intellectual Functioning ◽  
Clinical Impact ◽  
Review Of The Literature ◽  
Borderline Intellectual Functioning ◽  
General Quality ◽  
Meta Analyses ◽  
Over Time

Abstract. Borderline Intellectual Functioning (BIF) refers to a global IQ ranging from 71 to 84, and it represents a condition of clinical attention for its association with other disorders and its influence on the outcomes of treatments and, in general, quality of life and adaptation. Furthermore, its definition has changed over time causing a relevant clinical impact. For this reason, a systematic review of the literature on this topic can promote an understanding of what has been studied, and can differentiate what is currently attributable to BIF from that which cannot be associated with this kind of intellectual functioning. Using Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) criteria, we have conducted a review of the literature about BIF. The results suggest that this condition is still associated with mental retardation, and only a few studies have focused specifically on this condition.

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