scholarly journals Digestion and nitrogen balance using swine diets containing increasing proportions of coproduct ingredients and formulated using the net energy system1

2017 ◽  
Vol 95 (3) ◽  
pp. 1243-1252 ◽  
Author(s):  
J. A. Acosta ◽  
R. D. Boyd ◽  
J. F. Patience
Keyword(s):  
Nitrogen Balance ◽  
Net Energy ◽  
Swine Diets

The net energy value of three subtropical forages

1967 ◽  
Vol 18 (1) ◽  
pp. 137 ◽  
Author(s):  
N McCGraham
Keyword(s):  
Chemical Composition ◽  
Nitrogen Balance ◽  
Crude Protein ◽  
Chemical Constituents ◽  
Metabolizable Energy ◽  
Net Energy ◽  
Crude Fibre ◽  
Digestible Energy ◽  
Net Energy Value ◽  
Low Nitrogen

Energy and nitrogen balance experiments with three subtropical forages, a legume and two grasses, are reported. Each forage was given to four sheep at several levels of feeding. One of the forages had a low nitrogen content (4% crude protein) and was supplemented with urea and molasses containing 7 g nitrogen and 56 kcal/day. This caused voluntary consumption to increase by 50% and digestibility of all chemical constituents to increase by 6–12 units. Utilization of metabolizable energy for maintenance also improved by approximately 10%. Digestible energy (42–62%) was predicted quite accurately from chemical composition by means of published equations which refer to forages grown in temperate climates. Metabolizable energy was close to 82% of digestible energy, as found with non-tropical forages. Net availability of metabolizable energy for maintenance ranged from a very low 60% to 80%. It was predicted more accurately from percentage metabolizable energy than from digestible crude fibre: the reverse applied to net availability for production (40–50%).

scholarly journals 167 Analysis of variation in net energy prediction of feed ingredients fed to swine

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 62-62
Author(s):  
Noud Aldenhoven ◽  
Nestor A Gutierrez ◽  
Neil W Jaworski ◽  
Harmen van Laar
Keyword(s):  
Chemical Component ◽  
Chemical Components ◽  
Net Energy ◽  
Feed Ingredients ◽  
Energy Prediction ◽  
Fiber Analysis ◽  
Analysis Of Variation ◽  
Swine Diets ◽  
Analytical Variation

Abstract Precision of NRC and CVB net energy (NE) prediction equations was investigated by taking into account natural and analyzed variation of the chemical components (e.g., moisture, protein, starch, NDF, ADF, sugars, fat) for six feed ingredients used in swine diets. Precision is defined as the variation of the NE formula given the variation of its chemical components. Stochastic variables were substituted for the component values and the variation in nutrient composition was algebraically, not statistically, propagated to the NE value for both equations. This was done both, for the naturally occurring variation as published in CVB, and for a range of analytical variation values associated with wet chemistry analysis based on a range of values obtained by published ring-tests. Consequently, variation of the NE value and the contribution to variation of each chemical component in the NE equation were calculated. The variation of NE prediction using CVB is lower than using NRC. The main contributor for increased variation of the NRC NE is the NDF fraction. Whereas in CVB, this is replaced by the NSP fraction which is computed as a residue from the other chemical component values, forcing the sum of the composition to add to 100%. Furthermore, it was determined that analyzing all nutrients, in particular NDF and ADF, did not always reduce the variation of the NE equations. In conclusion, analytical variation, especially fiber analysis, must be critically examined and, preferably, sum to 100% to increase precision in the prediction of NE in feed ingredients. Otherwise, the use of a residue fraction, although nutritionally difficult to justify, actually increased precision in the NE equations. Note that it is unfair to compare both NE formulas based on precision alone. An interesting follow-up question is to take accuracy also into account when comparing CVB and NRC.

Effects of corn processing and cattle size on total tract digestion and energy and nitrogen balance

2021 ◽  
Author(s):  
E A Petzel ◽  
S Acharya ◽  
J M Zeltwanger ◽  
E A Bailey ◽  
D W Brake
Keyword(s):  
Nitrogen Balance ◽  
Gas Production ◽  
Metabolizable Energy ◽  
Net Energy ◽  
Eating Rate ◽  
Digestible Energy ◽  
Different Types ◽  
Physical Processing ◽  
Corn Processing ◽  
Calorimetry Data

Abstract This study used 18 calves (295 ± 29 kg) and 18 yearlings (521 ± 29 kg) fed whole, cracked or steam-flaked corn (SFC) to evaluate nutrient digestion and energy balance across different types of processed corn and sizes of cattle. Cattle were fed a diet comprised of 75% corn (DM-basis) from whole, cracked or SFC to 2.5-times maintenance energy requirements. Subsequently, cattle were placed in individual stanchions and urine and feces was collected together with measures of gas production via indirect calorimetry. Data were analyzed using the MIXED procedure of SAS. There was no interaction of corn processing and cattle size (P ≥ 0.40). Time spent ruminating (min/d) and rumination rate (min/kg DM intake; DMI) was not affected by corn processing or cattle size. Eating rate (min/kg DMI) was faster (P < 0.01) for yearlings compared to calves. Total tract starch digestion was greatest (P = 0.01) for cattle fed SFC (97.5%), intermediate in cattle fed cracked (92.4%) and least in cattle fed whole corn (89.5%). Dietary digestible energy and metabolizable energy (Mcal/kg DMI) were greater (P ≤ 0.05) for cattle fed SFC compared to cracked or whole. A greater proportion of digestible energy was lost to heat production (P = 0.01) in cattle fed whole corn compared to cracked and tended to be greater (P = 0.08) in cattle fed SFC than cracked. Conversion of digestible energy to metabolizable energy in this study was more closely related to a dynamic model used to estimate metabolizable energy of feeds to dairy cows than to a linear model used to predict metabolizable energy of feeds to beef cattle. If library estimates of net energy for maintenance are correct, then retained energy (Mcal/d) should have been similar between each type of processed corn; however, retained energy was greater (P < 0.01) for cattle fed cracked compared to whole corn and tended to be greater (P = 0.06) compared to SFC. Yet, observed amounts of net energy based on measures of retained energy were not different (P ≥ 0.60) between cracked and SFC. Nitrogen balance was not affected (P ≥ 0.30) by corn processing or cattle size, although cattle fed cracked had numerically greater (P ≤ 035) N retention. These data indicate that physical processing of corn provides greater net energy to cattle in comparison to whole corn.

BP Global Energy Outlook 2030

2013 ◽  
pp. 109-128 ◽  
Author(s):  
C. Rühl
Keyword(s):  
Emerging Economies ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Net Energy ◽  
Global Energy ◽  
The Past ◽  
Market Shares ◽  
The Us ◽  
Almost All ◽  
Oil Gas

This paper presents the highlights of the third annual edition of the BP Energy Outlook, which sets out BP’s view of the most likely developments in global energy markets to 2030, based on up-to-date analysis and taking into account developments of the past year. The Outlook’s overall expectation for growth in global energy demand is to be 36% higher in 2030 than in 2011 and almost all the growth coming from emerging economies. It also reflects shifting expectations of the pattern of supply, with unconventional sources — shale gas and tight oil together with heavy oil and biofuels — playing an increasingly important role and, in particular, transforming the energy balance of the US. While the fuel mix is evolving, fossil fuels will continue to be dominant. Oil, gas and coal are expected to converge on market shares of around 26—28% each by 2030, and non-fossil fuels — nuclear, hydro and renewables — on a share of around 6—7% each. By 2030, increasing production and moderating demand will result in the US being 99% self-sufficient in net energy. Meanwhile, with continuing steep economic growth, major emerging economies such as China and India will become increasingly reliant on energy imports. These shifts will have major impacts on trade balances.

NITROGEN CYCLES IN CROP ROTATIONS DIFFERING IN FERTILIZATION

2015 ◽  
Author(s):  
Saulius GUŽYS ◽  
Stefanija MISEVIČIENĖ
Keyword(s):  
Crop Rotation ◽  
Soil Nitrogen ◽  
Nitrogen Fertilizer ◽  
Nitrogen Balance ◽  
Mineral Soil ◽  
Crop Productivity ◽  
Drainage Water ◽  
Perennial Grasses ◽  
Crop Rotations ◽  
Cereal Crop

The use of nitrogen fertilizer is becoming a global problem; however continuous fertilization with nitrogen ensures large and constant harvests. An 8 year research (2006–2013) was conducted to evaluate the relationships between differently fertilized cultivated plant rotations. The research was conducted in Lipliunai (Lithuania) in the agroecosystem with nitrogen metabolism in fields with deeper carbonaceous soil, i.e. Endocalcari Endohypogleyic Cambisol (CMg-n-w-can). The research area covered three drained plots where crop rotation of differently fertilized cereals and perennial grasses was applied. Samples of soil, water and plants were investigated in the Chemical Analysis Laboratory of the Aleksandras Stulginskis University certified by the Environment Ministry of the Republic of Lithuania. The greatest productivity was found in a crop rotation with higher fertilization (N32-140). In crop rotation with lower fertilization (N24-90) productivity of cereals and perennial grasses (N0-80) was 11–35 % lower. The highest amount of mineral soil nitrogen was found in cereal crop rotation with higher fertilization. It was influenced by fertilization and crop productivity. The lowest Nmin and Ntotal concentrations in drainage water were found in grasses crop rotation. Crop rotations of differently fertilized cereals increased nitrogen concentration in drainage water. Nmin concentration in water depended on crop productivity, quantity of mineral soil nitrogen, fertilization, and nitrogen balance. The lowest nitrogen leaching was found in the crop rotation of grasses. Cereal crop rotation increased nitrogen leaching by 12–42 %. The usage of all crop rotations resulted in a negative nitrogen balance, which essentially depended on fertilization with nitrogen fertilizer.

Net Energy vs. T.D.N. in Evaluating the Efficacy of an All-Alfalfa Hay Ration for Milk Production

1951 ◽  
Vol 10 (4) ◽  
pp. 947-960 ◽  
Author(s):  
H. M. Irvin ◽  
J. C. Shaw ◽  
P. Saarinen ◽  
L. A. Moore
Keyword(s):  
Milk Production ◽  
Net Energy ◽  
Alfalfa Hay
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