Validation of the UK metabolisable energy system and other energy systems

2000 ◽  
Vol 2000 ◽  
pp. 95-95
Author(s):  
T. Yan ◽  
R. E. Agnew
Keyword(s):  
Dairy Cattle ◽  
Dairy Cows ◽  
Energy Systems ◽  
Energy System ◽  
Net Energy ◽  
Calorimetric Data ◽  
Lactating Dairy Cows ◽  
The World ◽  
Metabolisable Energy ◽  
The Uk

The UK metabolisable energy (ME) system for dairy cattle and net energy (NE) systems presently used in Europe and America were developed over 30 years ago. Recent studies have however indicated that these systems could under-predict the ME (MEm) or NE (NEm) requirement for maintenance for current dairy cows (e.g., Yan et al., 1997). The objective of the present study was to validate these systems using calorimetric data produced with lactating dairy cows and published around the world since 1976.

The use of production data of feeding studies in lactating dairy cows to validate energy feeding systems

2002 ◽  
Vol 2002 ◽  
pp. 102-102
Author(s):  
T. Yan ◽  
R. E. Agnew ◽  
J. J. Murphy ◽  
C. P. Ferris ◽  
F. J. Gordon
Keyword(s):  
Dairy Cows ◽  
Production Data ◽  
Net Energy ◽  
Calorimetric Data ◽  
Production Studies ◽  
Lactating Dairy Cows ◽  
Metabolisable Energy ◽  
Using Data ◽  
Feeding Systems

There is little information available in the literature on the validation of the currently adopted energy feeding systems developed from calorimetric data, using data obtained in production studies. The objective of the present study was to use production data from feeding studies to validate some metabolisable energy (ME) systems (AFRC, 1990 and 1993; SCA, 1990) and net energy (NE) systems (Van Es, 1978, INRA, 1989; NRC, 2001).

The use of regression techniques on calorimetric data to estimate the metabolisable energy requirements of lactating dairy cows

1997 ◽  
Vol 1997 ◽  
pp. 4-4
Author(s):  
T. Yan ◽  
F. J. Gordon ◽  
R. E. Agnew ◽  
M. G. Porter ◽  
D. C. Patterson
Keyword(s):  
Dairy Cows ◽  
Open Circuit ◽  
Energy Requirements ◽  
Gaseous Exchange ◽  
Calorimetric Data ◽  
Grass Silage ◽  
Lactating Dairy Cows ◽  
Holstein Friesian ◽  
Regression Techniques ◽  
Metabolisable Energy

The metabolisable energy (ME) requirement for maintenance (MEm) can be determined by measuring the fasting metabolism of the non-lactating cow, but this approach cannot encompass any differences in maintenance metabolic rate between lactating and non-lactating animals. The MEm and efficiency of ME use for lactation (k1) can also be estimated by regression of energy outputs against ME intake (MEI). During 1992 to 1995, a total of 221 Holstein/Friesian lactating dairy cows, which were offered grass silage-based diets, were subjected to gaseous exchange measurements in indirect open-circuit respiration calorimeters. The objective of the present study was to use these data to predict the MEm and k1 by a range of regression techniques for lactating dairy cows offered grass silage-based diets.

Metabolisable energy requirements of lactating dairy cows offered a straw/concentrate ration

1999 ◽  
Vol 1999 ◽  
pp. 33-33
Author(s):  
R.M. Kirkland ◽  
F.J. Gordon
Keyword(s):  
Dairy Cows ◽  
Energy Requirements ◽  
Calorimetric Data ◽  
Grass Silage ◽  
Lactating Dairy Cows ◽  
Regression Techniques ◽  
Metabolisable Energy

Previous studies at this Institute (Yan et al., 1997), using regression techniques on calorimetric data obtained with dairy cows offered grass silage based diets, have indicated that the metabolisable energy (ME) requirement for maintenance (MEm) is higher than that predicted using the equations of AFRC (1990). It was hypothesised, (Yan et al., 1997), that this higher MEm may reflect the use of diets containing ensiled grass and, furthermore, that ratio of grass silage:concentrates also influences MEm. In contrast, kl calculated by regression techniques was in line with that predicted using the equations of AFRC (1990). Against this background, the objective of the current study was to establish, using regression techniques, the MEm and kl on a non-grass silage based ration.

Identifying land cover suitability factors for photovoltaic installations with focus on cropland and urban areas

2021 ◽  
Author(s):  
Madhura Yeligeti ◽  
Wenxuan Hu ◽  
Yvonne Scholz ◽  
Kai von Krbek
Keyword(s):  
Land Cover ◽  
Urban Areas ◽  
Energy Systems ◽  
Energy System ◽  
Climatic Conditions ◽  
System Modelling ◽  
Solar Photovoltaic ◽  
Land Cover Types ◽  
The World ◽  
Urban Settlements

<p>Solar photovoltaic (PV) systems will foreseeably be an integral part of future energy systems. Land cover area analysis has a large influence on estimatiin of long-term solar photovoltaic potential of the world in high spatial detail. In this regard, it is often seen in contemporary works, that the suitability of various land cover categories for PV installation is considered in a yes/no binary response. While some areas like natural parks, sanctuaries, forests are usually completely exempted from PV potential calculations, other land over categories like urban settlements, bare, sparsely vegetated areas, and even cropland can principally support PV installations to varying degrees. This depends on the specific land use competition, social, economic and climatic conditions, etc. In this study, we attempt to evaluate these ‘factors of suitability’ of different land cover types for PV installations.</p><p>As a basis, the openly available global land cover datasets from the Copernicus Land Monitoring Service were used to identify major land cover types like cropland, shrubland, bare, wetlands, urban settlements, forests, moss and snow etc. For open area PV installations, with a focus on cropland, we incorporated the promising technology of ‘Agri-voltaics’ in our investigation. Different crops have shown to respond positively or negatively, so far, to growing under PV panels according to various experimental and commercial sources. Hence, we considered 18 major crops of the world (covering 85% of world cropland) individually and consequently, evaluated a weighted overall suitability factor of cropland cover for PV, for three acceptance scenarios of future.</p><p>For rooftop PV installations in urban areas, various socio-economic and geographical influences come in play. The rooftop area available and further usable for PV depends on housing patterns (roof type, housing density) which vary with climate, population density and socio-economic lifestyle. We classified global urban areas into several clusters based on combinations of these factors. For each cluster, rooftop area suitability is evaluated at a representative location using the land cover maps, the Open Street Map and specific characteristics of the cluster.</p><p>Overall, we present an interdisciplinary approach to integrate technological, social and economic aspects in land cover analysis to estimate PV potentials. While the intricacies may still be insufficient for planning small localized energy systems, this can reasonably benefit energy system modelling from a regional to international scale.</p>

Efficiencies of use of the metabolisable energy from feeds based on barley or sugar beet feed in immature sheep

1989 ◽  
Vol 1989 ◽  
pp. 60-60 ◽  
Author(s):  
G.C. Emmans ◽  
M.R. Cropper ◽  
W.S. Dingwall ◽  
H. Brown ◽  
J D Oldham ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Energy Systems ◽  
Quantitative Relationship ◽  
Energy System ◽  
Single Dimension ◽  
Energy Retention ◽  
Gross Energy ◽  
Metabolisable Energy

The ARC (1980) energy system sees growth in the single dimension of energy retention (ER) which increases, with diminishing marginal efficiency, as ME intake increases. The quantitative relationship between ME intake and ER is predicted from q, the proportion of the gross energy which is metabolisable. An experiment on growing sheep on controlled feeding of different feeds was carried out to provide data suitable for testing ARC (1980) and other energy systems.Scottish Blackface wether sheep in single pens, entered the experiment at 25 kg liveweight (LW), when 11 were slaughtered. The remainder were allocated to 3 x 3 x 3 treatments with an intended 4 replicates per treatment. The factors were (i) feeds: feeds B, U and M shown in Table 1, (ii) levels of feeding. L, M and H where H was 936 g/d at 25 kg and was increased by 52 g/d each week, L was half H and M half-way between L and H, (iii) slaughter point, after 9 or 18 weeks, or at 40 kg liveweight.

scholarly journals Prediction of nitrogen use in dairy cattle: a multivariate Bayesian approach

2014 ◽  
Vol 54 (12) ◽  
pp. 1918 ◽  
Author(s):  
K. F. Reed ◽  
L. E. Moraes ◽  
J. G. Fadel ◽  
D. P. Casper ◽  
J. Dijkstra ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Energy Content ◽  
Model Development ◽  
Parameter Estimate ◽  
Absorption Efficiency ◽  
Net Energy ◽  
Energy Status ◽  
Covariate Effects ◽  
Metabolisable Energy ◽  
N Use

Quantification of dairy cattle nitrogen (N) excretion and secretion is necessary to improve the efficiency with which feed N is converted to milk N (ENU). Faecal and urinary N excretion and milk N secretion are correlated with each other and thus are more accurately described by a multivariate model that can accommodate the covariance between the three observations than by three separate univariate models. Further, by simultaneously predicting the three routes of excretion and taking advantage of the mass balance relationships between them, covariate effects on N partitioning from feed to faeces and absorbed N and from absorbed N to milk and urine N and animal ENU can be estimated. A database containing 1094 lactating dairy cow observations collated from indirect calorimetry experiments was used for model development. Dietary metabolisable energy content (ME, MJ/kg DM) increased ENU at a decreasing rate, increased the efficiency with which feed N was converted to absorbed N and decreased the efficiency with which absorbed N was converted to milk N. However, the parameter estimate of the effect of ME on post-absorption efficiency was not different from zero when the model was fitted to a data subset in which net energy and metabolisable protein were at or above requirement. This suggests the effect of ME on post-absorption N use is dependent on the energy status of the animal.

scholarly journals GREEN ENERGY: SALVATION OR THREAT TO THE GLOBAL ECONOMIC AND ENERGY SYSTEM

2021 ◽  
Author(s):  
Sergiy Korinnyi ◽  
Mariia Mikhailutsa ◽  
Anastasiia Bondarenko
Keyword(s):  
Energy Storage ◽  
Alternative Energy ◽  
New Technologies ◽  
Renewable Energy Sources ◽  
Energy Systems ◽  
Energy System ◽  
Green Energy ◽  
Human Potential ◽  
Energy Sources ◽  
The World

The article examines a set of issues related to "green energy" in the world, problems and opportunities from the introduction of alternative energy sources for greening the economy, developing sustainable economy and preserving human potential. Analytical works of some Ukrainian authors have been studied, in which the current state, obstacles to the realization and prospects of "green energy" in the world have been determined. The purpose of the article is to refute the allegations about the need to immediately stop the introduction of "green technologies", including the construction of solar stations. There are two opposing views on the need for green energy, which have been being discussed around the world for the past few decades. The most popular evidence from both sides on this issue is given, in particular, that the planet can be saved only through the active use of renewable energy sources, and on the other hand, that "green energy" at the current level of human development will cause even more environmental and economic problems. The arguments most often expressed by opponents of the active introduction of "green energy" are highlighted, namely: the high cost of new technologies compared to existing types of generation; the inability of "green energy" to solve the problem of warming on the planet with reference to scientific research on the amount of CO2 emissions from different types of generation as a major factor in warming; danger to the energy systems of all countries of the world due to the instability of energy production by natural factors. Counter-arguments on these issues are provided and evidence of the ability and necessity to use clean technologies is provided. The problem, on which the opinions of both parties coincide, is highlighted - the reluctance of "green" investors to spend money on storage systems, energy storage and stabilization of energy systems due to their high cost, size, insufficient energy consumption and insufficient duration of work. It is noted that the issue of developing the latest energy storage and stabilization systems and their installation at new and existing RES stations needs to be addressed immediately, but is not an obstacle to the further development of green energy.

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