Aspects of digestive function in sheep related to phenotypic variation in methane emissions

2019 ◽  
Vol 59 (1) ◽  
pp. 55 ◽  
Author(s):  
J. J. Bond ◽  
M. Cameron ◽  
A. J. Donaldson ◽  
K. L. Austin ◽  
S. Harden ◽  
...  

Ruminant livestock contribute to atmospheric methane (CH4) from enteric microbial fermentation of feed in the reticulo-rumen. Our research aimed to increase understanding of how digestive characteristics and rumen anatomy of the host animal contribute to variation in CH4 emissions between individual sheep. In total, 64 ewes were used in an incomplete block experiment with four experimental test periods (blocks). Ewes were chosen to represent the diversity of phenotypic variation in CH4 emissions: there were at least 10 offspring from each of four sires and a range of liveweights. Throughout the experiment, the ewes were fed equal parts of lucerne and oaten chaff, twice daily, at 1.5 times the maintenance requirements. Daily CH4 emission (g/day) increased significantly (P < 0.001) with an increasing dry-matter intake (DMI) and reticulo-rumen volume (P < 0.001). Lower methane yield (g CH4/kg DMI) was associated with shorter mean retention times of liquid (r = 0.59; P < 0.05) and particle (r = 0.63; P < 0.05) phases of the digesta in the rumen. Significant between sire variation was observed in CH4 emissions and in rumen volume (P = 0.02), the masses of liquids (P = 0.009) and particles (P < 0.03) in the rumen and the proportion of gas in the dorsal sac of the rumen (P = 0.008). The best predictors of variation in CH4 emissions due to the host were DMI, CO2 emissions, rumen volume, liveweight, mean retention time of particles in the rumen, dorsal papillae density and the proportion of liquid in the contents of the rumen compartments.

2016 ◽  
Vol 56 (11) ◽  
pp. 1897 ◽  
Author(s):  
C. A. Ramírez-Restrepo ◽  
H. Clark ◽  
S. Muetzel

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.


1981 ◽  
Vol 32 (2) ◽  
pp. 171-178 ◽  
Author(s):  
F. J. Gordon

ABSTRACTA randomized block experiment was used to assess the effects of wilting of herbage prior to ensiling. Three silages, each a composite of three harvests taken over the season, were prepared by ensiling herbage as unwilted, medium-wilted or high-wilted material with mean dry-matter contents in the resulting silages of 192, 254 and 455g/kg respectively. The silages were ensiled in bunker silos using the same harvesting machinery and with formic acid applied at the rate of 2 81/t of herbage. The silages were offered to 81 January- and February-calving cows from the 8th day post partum until going to pasture on 27 April, with a mean period on treatmen t of 92 days. In addition, all animals received a fixed concentrate allowance of 7·6 kg/day. Wilting increased silage dry-matter intake, the mean intakes being 9·2, 9·4 and 10·0kg/day for the unwilted, medium-wilted and high-wilted material respectively, but resulted in a significant depression in milk yield, with the yields obtained during the final 14 days on treatment being 23·6, 21 -8 and 21·5kg/day respectively. Milk composition, live weight, body condition, total ration digestibility and nitrogen-balance data are also presented.


2020 ◽  
Vol 60 (1) ◽  
pp. 96 ◽  
Author(s):  
Arjan Jonker ◽  
Peter Green ◽  
Garry Waghorn ◽  
Tony van der Weerden ◽  
David Pacheco ◽  
...  

Enteric methane (CH4) emissions and dry-matter intake (DMI) can be accurately and precisely measured in respiration chambers (RC), whereas automated head chambers (GreenFeed; GF) and the SF6 tracer method can provide estimates of CH4 emissions from grazing cattle. In New Zealand, most dairy cattle graze pasture and, under these conditions, DMI also has to be estimated. The objective of the current study was to compare the relationship between CH4 production and DMI of New Zealand dairy cattle fed forages using the following four measurement methods: RC with measured DMI (RC); sulfur hexafluoride (SF6) with measured DMI (SF6-DMI); SF6 with DMI estimated from prediction equations or indigestible markers (SF6); GF with measured or estimated DMI (GF). Data were collected from published literature from New Zealand trials with growing and lactating dairy cattle fed forage-based diets and data were analysed using a mixed-effect model. The intercept of the linear regression between CH4 production and DMI was not significantly different from zero and was omitted from the model. However, residual variance (observed–predicted values) increased with an increasing DMI, which was addressed by log-transforming CH4 per unit of DMI and this model was used for final data analysis. The accuracy of the four methods for predicting log CH4 per unit of DMI was similar (P = 0.55), but the precision (indicated by residuals) differed (P &lt; 0.001) among methods. The residual standard deviations for SF6, GF and SF6-DMI were 4.6, 3.4 and 2.1 times greater than the residuals for RC. Hence, all methods enabled accurate prediction of CH4 per unit of DMI, but methodology for determining both CH4 and DMI affected their precision (residuals).


2008 ◽  
Vol 48 (2) ◽  
pp. 240 ◽  
Author(s):  
T. W. Knight ◽  
G. Molano ◽  
H. Clark ◽  
A. Cavanagh

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.


1994 ◽  
Vol 74 (2) ◽  
pp. 305-313 ◽  
Author(s):  
J. Z. Adamczewski ◽  
P. F. Flood ◽  
R. K. Chaplin ◽  
J. A. Schaefer

We studied changes in body weight, intake, retention time and apparent digestibility of a supplemented brome-alfalfa hay by mature muskoxen held near Saskatoon, Saskatchewan during two seasonal cycles. Body weights and voluntary intake were monitored during 16 trials from late March 1990 to December 1991, in four annually breeding females and in three hysterectomized females. Retention time of the hay and apparent digestibility of the diet were estimated in winter and summer 1991 from fecal excretion of chromium (Cr) after a pulse dose of Cr-mordanted hay, and from forage/fecal concentrations of chromic oxide, respectively, in six non-breeding muskoxen. Mean (±SE) body weights of breeding females were greatest in February and March (248 ± 5 kg) and lowest following calving in late May or early June (216 ± 6 kg), while mean weight of hysterectomized females declined little from a peak of 228 ± 21 kg in February-March to a low of 213 ± 21 kg in July. Mean dry matter intake of breeding females was highest in July and August (62 ± 3.6 g d−1 kg−0.75) then declined slowly to its lowest point in March and April (41 ± 0.7 g d−1 kg−0.75). Dry matter intake of hysterectomized cows was less clearly seasonal but averaged 42 ± 1.7 g d−1 kg−0.75 in late winter and 50 ± 4.9 g d−1 kg−0.75 in mid-summer. Mean retention time of hay, calculated using a noncompartmental model, declined significantly from 114 ± 4 h in March to 95 ± 4 h in July. Apparent organic matter digestibility decreased significantly from 73.8 ± 0.8% in winter to 61.7 ± 1.3% in summer. Compared with other ruminants, muskoxen are grazers exceptionally well-suited to digesting graminoid forage, with relatively low maintenance requirements and prolonged retention times. Most of the seasonal changes in weight and intake of breeding females could be ascribed to reproductive cost, but there also appeared to be seasonal effects on intake, retention time and body weight in non-breeding muskoxen. Key words: Digestibility, intake, maintenance requirements, muskoxen, retention time, seasonal variation


2008 ◽  
Vol 48 (2) ◽  
pp. 234 ◽  
Author(s):  
C. S. Pinares-Patiño ◽  
G. Molano ◽  
A. Smith ◽  
H. Clark

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.


1972 ◽  
Vol 12 (57) ◽  
pp. 365 ◽  
Author(s):  
MJ Playne ◽  
KP Haydock

The voluntary dry matter intake, digestibility and chemical composition of Townsville stylo and of black spear grass cut at different times of the year from a site near Townsville, Queensland, have been examined using penned sheep. Nitrogen, sulphur, and phosphorus intakes and retention in the sheep were measured. The concentrations of N, P, S, Na, and Ca in most cuts of spear grass and P and Na in Townsville stylo were less than the published requirements of animals. With spear grass, digestible dry matter intake declined rapidly from January to April and more slowly from April to October and by mid-March fell below the estimated energy requirements for maintenance of sheep. There was little change in digestible dry matter intake of Townsville stylo between February and May and the level was well above maintenance requirements. Dry matter intake and dry matter digestibility were linearly related but only about 50 per cent of variations in intake were caused by variations in digestibility. Nitrogen balance was linearly related to nitrogen intake, and sulphur balance was linearly related to sulphur intake. Phosphorus intakes were usually less than 1 g P day-l and animals were usually in negative P retention.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 475-476
Author(s):  
Emily Conlin ◽  
Herbert Lardner ◽  
Jennifer L Ellis ◽  
Ira B Mandell ◽  
Katharine M Wood

Abstract Reducing greenhouse gas (GHG) emissions from beef cattle production systems has continuously been recognized as an important strategy to help mitigate climate change. This experiment was conducted to determine the optimum inclusion level of biochar (Oregon Biochar Solution, White City, OR) in the diet to reduce enteric methane (CH4) emissions from beef cows. Biochar is a stable form of carbon produced through low-oxygen and high-temperature pyrolysis of organic matter (typically forestry waste). Using a 4 x 4 Latin square design, pregnant beef cows (n = 8) of similar weight and stage of pregnancy were supplemented with biochar daily at 0, 1, 2, or 3% of total dry matter intake (DMI). Biochar was added to a pellet containing 45% biochar, 42.5% wheat midds, 10% canola oil, and 2.5% dry molasses to facilitate ease of feeding and encourage biochar consumption. Each 21-day period consisted of 14 days for diet adaptation and 7 days for data collection. Enteric gas emissions were measured using C-Lock GreenFeed trailers (C-Lock Inc., Rapid City, SD, USA) and DMI was collected using Insentec feeders (Insentec, Voorsterweg, The Netherlands). Enteric CH4 emissions expressed in g CH4/day, g CH4/kg DM, and g CH4/kg BW were not affected by biochar supplementation (P ≥ 0.41), although the 3% inclusion was numerically lowest. For all parameters expressing CH4 emissions, linear and quadratic effects for inclusion rate were not significant (P ≥ 0.19). Dry matter intake and cow body weights were not affected by biochar supplementation (P ≥ 0.34). These results suggest that biochar was ineffective for reducing CH4 emissions from beef cows fed a high forage diet (50% haylage, 30% straw, 17% corn silage) with no effects on animal performance. Further research should investigate whether type of biochar or higher inclusion levels of biochar can reduce CH4 emissions from beef cattle.


2019 ◽  
Vol 59 (5) ◽  
pp. 891 ◽  
Author(s):  
P. J. Moate ◽  
S. R. O. Williams ◽  
M. H. Deighton ◽  
M. C. Hannah ◽  
B. E. Ribaux ◽  
...  

There has been little research that has quantified methane (CH4) yields when dairy cows consume diets containing wheat grain. Furthermore, although rumen-fistulated animals have been used in many experiments concerned with measuring CH4 emissions, no research has examined the effect of rumen fistulation on in vivo CH4 emissions and yield. This experiment examined the effects of including either wheat or corn grain in the diet and the effects of rumen fistulation on yields of milk and milk components, CH4 emissions, yields, and intensities. Eight rumen-fistulated and six non-fistulated Holstein dairy cows in late lactation were offered a wheat-based diet (WHT) and a corn-based diet (CRN) in a crossover design. For the WHT diet, cows were offered daily, 22.4 kg DM containing 45.5% lucerne hay, 8.9% canola meal, 0.5% mineral mix, 0.5% molasses powder and 44.6% rolled wheat. The CRN diet was similar to the WHT diet except that rolled corn replaced the wheat. There was no difference between the WHT and CRN diets on mean milk yields (27.8 vs 27.9 kg/day), but the WHT diet substantially reduced milk fat concentration (2.76 vs 4.23%) and milk fat yield (0.77 vs 1.18 kg/day). Methane emissions (218 vs 424 g/day), CH4 yield (11.1 vs 19.5 g/kg dry matter intake) and CH4 intensity (7.6 vs 15.7 g/kg milk) were all reduced ~45% by the WHT diet compared with the CRN diet. Rumen fistulation did not affect dry matter intake, milk production, milk composition or CH4 emissions, but decreased CH4 yield and intensity. Including wheat in the diet of dairy cows has the potential to be an effective strategy to reduce their greenhouse gas emissions. In addition, rumen fistulation was associated with a small reduction in CH4 yield and intensity, and this should be considered when using rumen-fistulated cows in research concerned with CH4 emissions.


1976 ◽  
Vol 23 (1) ◽  
pp. 125-128
Author(s):  
F. J. Gordon

SUMMARYTwenty-four lactating cows were used in a 6-week randomized block experiment to assess the effect of replacing 2·4 kg of cereal-based concentrate dry matter by either 2·6 or 3·2 kg of kale dry matter for cows with ad libitum access to grass silage. Milk yield, milk composition and live-weight change were not affected by the inclusion of kale. Silage dry-matter intake was significantly lower on the kale treatments than with concentrate, being 8·51, 7·89 and 7·95 kg per day for the concentrate, low-kale and high-kale supplements respectively. Energy digestibilities were 68·1, 74·4 and 76·4% and nitrogen digestibilities 67·1, 74·9 and 78·8% for the three treatments respectively.


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