Jørgen Steen Madsen

Methods for Measuring and Estimating Methane Emission from Ruminants

Simple Summary Knowledge about methods used in quantification of greenhouse gasses is currently needed due to international commitments to reduce the emissions. In the agricultural sector one important task is to reduce enteric methane emissions from ruminants. Different methods for quantifying these emissions are presently being used and others are under development, all with different conditions for application. For scientist and other persons working with the topic it is very important to understand the advantages and disadvantage of the different methods in use. This paper gives a brief introduction to existing methods but also a description of newer methods and model-based techniques. Abstract This paper is a brief introduction to the different methods used to quantify the enteric methane emission from ruminants. A thorough knowledge of the advantages and disadvantages of these methods is very important in order to plan experiments, understand and interpret experimental results, and compare them with other studies. The aim of the paper is to describe the principles, advantages and disadvantages of different methods used to quantify the enteric methane emission from ruminants. The best-known methods: Chambers/respiration chambers, SF6 technique and in vitro gas production technique and the newer CO2 methods are described. Model estimations, which are used to calculate national budget and single cow enteric emission from intake and diet composition, are also discussed. Other methods under development such as the micrometeorological technique, combined feeder and CH4 analyzer and proxy methods are briefly mentioned. Methods of choice for estimating enteric methane emission depend on aim, equipment, knowledge, time and money available, but interpretation of results obtained with a given method can be improved if knowledge about the disadvantages and advantages are used in the planning of experiments.

Accuracy of noninvasive breath methane measurements using Fourier transform infrared methods on individual cows

Individual methane (CH(4)) production was recorded repeatedly on 93 dairy cows during milking in an automatic milking system (AMS), with the aim of estimating individual cow differences in CH(4) production. Methane and CO(2) were measured with a portable air sampler and analyzer unit based on Fourier transform infrared (FTIR) detection. The cows were 50 Holsteins and 43 Jerseys from mixed parities and at all stages of lactation (mean=156 d in milk). Breath was captured by the FTIR unit inlet nozzle, which was placed in front of the cows head in each of the 2 AMS as an admixture to normal barn air. The FTIR unit was running continuously for 3 d in each of 2 AMS units, 1 with Holstein and another with Jersey cows. Air was analyzed every 20 s. From each visit of a cow to the AMS, CH(4) and CO(2) records were summarized into the mean, median, 75, and 90% quantiles. Furthermore, the ratio between CH(4) and CO(2) was used as a derived measure with the idea of using CO(2) in breath as a tracer gas to quantify the production of methane. Methane production records were analyzed with a mixed model, containing cow as random effect. Fixed effects of milk yield and daily intake of the total mixed ration and concentrates were also estimated. The repeatability of the CH(4)-to-CO(2) ratio was 0.39 for Holsteins and 0.34 for Jerseys. Both concentrate intake and total mixed ration intake were positively related to CH(4) production, whereas milk production level was not correlated with CH(4) production. In conclusion, the results from this study suggest that the CH(4)-to-CO(2) ratio measured using the noninvasive method is an asset of the individual cow and may be useful in both management and genetic evaluations.

The Danish Model of Industrial Relations: Erosion or Renewal?

The Danish model represents one of the most solidly-based industrial relation (IR) systems in Europe, and is today internationally regarded as an exemplar owing to its effective combination of flexibility and security in labour-market regulation. But in an increasingly globalized world even this model has come under pressure. The pressure comes from three different directions: (1) from EU regulation; (2) from the national political system; and, (3) from the parties at enterprise level. The organized or centralized decentralization of the collective bargaining system that was seen as the answer to the increased competitive pressure of internationalization would appear to have reached its limit and to have been replaced by a trend towards multi-level regulation. Whether this trend will lead to renewal or erosion of the Danish model will be revealed over the coming years. There are signs that indicate the models continued robustness, but there are also signs of weakening. The outcome is not only of national interest, but also has international relevance, since Denmark can be seen as the IR model par excellence. As a critical case the development of the Danish model is an indicator of the traditional IR systems future prospects in general.

Challenging Scandinavian employment relations: the effects of new public management reforms

Building on the convergence/divergence approach, this paper examines whether recent new public management (NPM) inspired reforms entailing inter alia cutbacks in the public sector, marketisation and management by performance measures have had significant implications for service provision and employment relations in the Danish, Norwegian and Swedish public sector. In this paper, we argue that although differences exist across the Scandinavian countries, it is evident that they have managed to adopt and implement NPM-inspired reforms without dismantling their universal welfare services and strong traditions of collective bargaining in the public sector. However, this restructuring is taking its toll on the work environment.

The survival of the Danish model : a historical sociological analysis of the Danish system of collective bargaining

Part 1 A theoretical basis for the analysis of industrial relations - the development of institutions: the end of institutions? Part 2 The Danish system of collective bargaining - the origins of the Danish system negotiation rules and concatenation the third actor structural stagnation. Part 3 Centralized decentralization - complementary concepts: degrees of centralization a surge in structural development towards the year 2000.

Endogenous Amino Acid Flow in the Duodenum of Dairy Cows

Larsen M., Madsen T. G., Weisbjerg M. R., Hvelplund T., Madsen J. (Danish Institute of Agricultural Sciences, Foulum, P.O. Box 50, DK8830 Tjele, Denmark, and The Royal Veterinary and Agricultural University, Grønnegaardsvej 2, DK-1870 Frederiksberg C, Denmark). Endogenous amino acid flow in the duodenum of dairy cows. Accepted October 4, 1999. Acta Agric. Scand., Sect. A, Animal Sci. 50: 161– 173, 2000.

Appropriate methods for the evaluation of tropical feeds for ruminants

Abstract The nutritive value of a feedstuff is dependent on the intake and on the amount of nutrients absorbed from the ingested feedstuff during its passage through the gastro intestinal tract. This paper, however, focuses only on the potentials and limitations of some methods found appropriate to estimate the feed intake, energy value and the protein value of feedstuffs. It was concluded that experiments should be made to establish the potential feed intake of different tropical feeds. A system based on the physical fill of feed in the rumen is appropriate as the dominant limitation for intake in ruminants is physical fill of partly digested plant fibers in the rumen. The degradation and passage rates of NDF in the rumen is a potentially useful method to predict the physical fill of fibrous feeds. The potential digestibility of a wide variety of feeds can be determined with reasonable accuracy by using rumen fluid in vitro. The energetic value of concentrate feeds can moreover be determined by enzymatic methods which do not require rumen fluid. For very poor roughage, in vitro methods are less reproducible and should be supplemented with the nylon bag method. The traditional chemical analyses, e.g. for crude fibre, NDF or ADF do not predict the digestibility well, except for feeds where the relationship between the chemical analysis and the digestibility has been established beforehand. The protein value of a feed depends on rumen degradation as well as the amino acid content and digestibility of the undegraded protein passing to the small intestine. The nylon bag method is the only available tool to generally predict the rumen degradation but the between laboratory variation is too big and figures obtained can only be used within laboratory. To improve reproducibility and reduce costs an alternative method is required, e.g. an enzymatic method. The intestinal digestibility of undegraded protein can only be predicted with the mobile bag technique and also here there is a need for alternative methods. Too little research is concerned with quantitative and qualitative protein need of the rumen microbes.

Phases and dynamics in the development of EU industrial relations regulation

In this article the authors discuss whether it is possible to identify the existence of a European IR-system. They try to identify important phases and dynamics in the emergence of what is termed the European IR-model. It is argued that traditional IR-theory should be combined with theories which allow more extensive consideration of politological and institutional phenomena when analysing IR developments at pan-European level.

The influence of urea supplementation or treatment of rice straw and fish meal supplementation on rumen environment and activity in sheep

The rate and extent of degradation of dry matter (DM) of untreated rice straw (URS) was studied in four rumen environments created by feeding urea-supplemented rice straw (USRS) or urea-treated rice straw (UTRS) as basal diets with or without fish meal (FM) supplement. In addition the animals were given rice bran (RB) to form a straw to RB ratio of 70:30 and adequately supplemented with a mineral and vitamin premix. Four rumencannulated adult sheep in a 4 × 4 Latin square were used. Rumen pH, NH3-N and volatile fatty acids (VFA) were measured in the same experiment. An incomplete but balanced 4 × 4 Latin square was used to measure the rate and extent of degradation of USRS and UTRS in the rumen of sheep where the same feeds were fed as basal diets. The results showed that the extent and rate of degradation of URS were more or less similar when incubated in the rumen of sheep fed the four treatment diets. Similarly, there was little difference in degradation between USRS and UTRS incubated in the rumen of sheep given these feeds as basal diets with or without FM supplementation. The UTRS was degraded to a higher degree than URS and USRS and this was reflected in a significantly (P < 0.001) lower concentration of rumen NH3-N in the two UTRS diets compared with USRS diets. The rumen pH and VFA concentrations did not show any differences between the four rumen environments. Although urea treatment and FM supplementation had been expected to show a stimulatory effect on microbial density and colonisation of cellulolytic bacteria it was not possible to detect any difference in the URS degradation between the four treatment diets. The reason may be that USRS together with 30% RB created an optimal rumen environment for rice straw degradation which was not improved by FM supplementation or by feeding the more degradable UTRS.

Influence of urea treatment or supplementation on degradation, intake and growth performance of goats fed rice straw diets

Rice straws were either treated with urea (50 g urea in 600 ml of water) and stored for 2 weeks or sprayed with urea solution (20 g urea in 600 ml of water kg−1 DM straw) and fed immediately. These two basal diets were supplemented with rice bran (RB), mineral and vitamin premix, common salt, with or without fish meal (FM) to form four treatment diets. In situ degradability studies and chemical analyses were used to test the effectiveness of urea treatment or supplementation in a completely randomized design using three fistulated sheep fed a standard diet. Animal response when fed urea-treated rice straw (UTRS) or urea-supplemented rice straw (USRS), supplemented with RB with or without FM, was studied using 32 growing female dairy goats in a completely randomized design. Growth rate and dry matter intake (DMI) were recorded for 90 days. The results showed that N content increased from 7.0 (untreated rice straw (URS)) to 17.4 and 18.6 g N kg−1 DM for USRS and UTRS, respectively. The rate of DM degradation was significantly (P < 0.01) increased from 1.9% (URS) and 3.5% (USRS) to 4.5% h−1 (UTRS). The 48 h DM degradability was improved from 42.5% (URS) and 55.1% (USRS) to 65.7% (UTRS). The effective degradability (ED) calculated assuming passage rates of 2% h−1 and 4% h−1, respectively, were 39.6% and 31.3% (URS), 45.3% and 37.3% (USRS) and 53.6% and 44.1% (UTRS). Urea treatment increased daily straw DMI to 59.3 g kg−1W0.75 compared with 23.1 g for USRS. This corresponds to 2.9% and 1.2% of body weight, respectively. The total DMI was increased from 45.8 (2.3% of body weight) to 89.4 (4.3% of body weight) g kg−1W0.75 day−1 for USRS and UTRS based diets, respectively. Both urea treatment and FM supplementation significantly (P < 0.001) increased average daily gain (ADG) from 3.3 ± 1.5 (USRS) to 36.9 ± 1.5 g day−1 (UTRS) and from 13.0 ± 1.5 g day−1 (USRS + FM) to 49.1 ± 1.5 g day−1 (UTRS + FM). It was concluded that urea treatment promoted DMI with a corresponding increased growth performance by goats due to increased rate and extent of degradation of UTRS compared with USRS. Similarly, when a small amount of FM was supplemented increased weight gains and feed efficiency were observed on both USRS and UTRS based diets.