scholarly journals 384 Metabolizable energy content of feeds: Errors that need attention

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 157-158
Author(s):  
Fredric N Owens ◽  
Richard Zinn

Abstract Feedlot performance is predicted reliably from DMI and diet NE. Tabular NE values in turn commonly are calculated from TDN either measured in digestion trials or predicted from nutrient compositions. When estimated from nutrient composition (NRBC, 2016), TDN values for feeds were related imprecisely (R2 = 0.83) to in vivo TDN values (NRC, 2000); deviations ranged from -29% to 162%. Traditionally, DE has been calculated as TDN percentage times 0.044, an assumed calorie content of carbohydrate (4.4 kcal/g). Surprisingly, this value is 5% greater than the heats of combustion of DM from isolated starch, cellulose, and glycogen (4.1788, 4.1810, and 4.1868 kcal/g; Blaxter, 1962; The Energy Metabolism of Ruminants). Being “carbohydrate-equivalent energy,” TDN includes the extra calories from lipid whereas urinary energy (UE) lost during catabolism of digested protein automatically is deducted. When determined calorimetrically, ME equals DE minus both gas energy (GasE) loss and UE. But when DE is being calculated from TDN, UE from digested CP already has been subtracted. Double deduction for UE underestimates ME content of high protein feeds. When DE is calculated from TDN, ME equals DE minus only GasE. Using data assembled by Galyean et al. (2016), multiple regression revealed that GasE was predicted more accurately from dietary NDF and lipid concentrations (GasE, % of DE = 4.87 + 0.131 x NDF - 0.331 x EE; R2 = 0.69) than from diet DE (R2 = 0.27). From this formula, GasE loss as a fraction of DE of feeds ranges from 5 to 15% except for isolated fats than have a negative value; non-additivity across feeds complicates formulation of least cost diets. Correcting discrepancies in calculating ME from TDN should improve reliability of predicting the cost of ME from various feeds and for quantifying feed requirements for maintenance and gain of cattle fed diverse diets.

1996 ◽  
Vol 1996 ◽  
pp. 41-41
Author(s):  
A.T. Adesogan ◽  
E. Owen ◽  
D.I. Givens

Estimates of the metabolisable energy (ME) content of whole crop wheat (WCW) derived using measured energy losses as methane (ELMm) are lacking due to the cost of measuring ELMm. Published ME values of WCW are largely calculated using predicted energy losses as methane (ELMp, Blaxter and Clapperton, 1965) or digestible organic matter content (DOMD) in vivo. However, there appears to be no published information about the accuracy with which DOMD in vivo or ELMp predicts the ME content of WCW. Therefore, this study assessed the validity of such ME predictions by comparing them with ME contents calculated using ELMm.


2014 ◽  
Vol 15 (1) ◽  
pp. 172-181 ◽  
Author(s):  
Vanessa Peripolli ◽  
Ênio Rosa Prates ◽  
Júlio Otávio Jardim Barcellos ◽  
Cássio André Wilbert ◽  
Cláudia Medeiros Camargo ◽  
...  

The interest in using crude glycerol in animal feeding has reemerged due to its increasing availability and favorable price resulting from the expansion of biofuel industry. The objective of the present study was to evaluate the effects of substituting corn for crude glycerol at different levels in the diet on ruminal fermentation using in-vitro true digestibility parameters. The experimental treatments consisted of substituting corn for liquid crude glycerol (0; 4; 8 and 12%) in dry matter basis. Diets consisted of 60% alfalfa hay and 40% corn and glycerol substituted the corn in the diet. In addition to the 48 hours traditionally applied in digestibility assays, different in-vitro digestibility times were used (0; 4; 8; 16; 48, 72 and 96 hours) in order to study digestion kinetics. The dietary corn substitution for increasing crude glycerol levels did not affect ammonia nitrogen content, metabolizable energy content, in-vitro digestibility of organic matter and neutral detergent fiber, nor ruminal degradation parameters. However this by-product of biodiesel production may be tested in-vivo as an alternative energy feedstuff in ruminant diets.


1979 ◽  
Vol 93 (1) ◽  
pp. 217-222 ◽  
Author(s):  
K. H. Menke ◽  
L. Raab ◽  
A. Salewski ◽  
H. Steingass ◽  
D. Fritz ◽  
...  

SUMMARYA rapid method for measuring gas production during incubation of feedingstuffs with rumen liquor in vitro is described. Gas production in 24 h from 200 mg feed dry matter was well correlated with digestibility of organic matter, determined in vivo with sheep. Multiple regression analysis, when it included data from proximate analysis, resulted in an equation (R = 0·98) for prediction of metabolizable energy content, based on 30 experiments with rations varying in protein and crude fibre content, and 59 other experiments with concentrates. Energy content was in the range of 7·7–13·2 MJ ME/kg D.M. (± S.D. = 11·17 ± 1·08). The residual standard deviation of the equation was 0·25 MJ. Gas production was measured in calibrated syringes. The only chemical determinations needed are dry matter, protein and fat. Differences in activity between batches of rumen liquor are corrected by reference to gas production with standard feedingstuffs (hay meal and maize starch).


Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 907
Author(s):  
Olga Lasek ◽  
Jan Barteczko ◽  
Justyna Barć ◽  
Piotr Micek

The study aimed to determine the effect of nutrients of wheat (nine cultivars) and maize (nine cultivars) grain on nitrogen balance and apparent metabolizable energy (AMEN) content for broiler chickens. In vivo digestibility and balance trials were carried out with 90 Ross 308 chickens (2 × 9 groups with 5 birds per group) aged from 42 to 49 days, separately for each cultivar. Considerable variation within each cereal species in fiber and non-fiber carbohydrate fractions and nutrient digestibility of grain were demonstrated. Additionally, regression equations were proposed which allow the estimation of AMEN content of wheat and maize grain varieties based on simple analytical procedures, including cell wall components, starch, and sugars. For practical purposes, these equations seem to be the best solution while reducing time, labor, and cost of analytical procedures.


1970 ◽  
Vol 24 (2) ◽  
pp. 517-535 ◽  
Author(s):  
D. A. T. Southgate ◽  
J. V. G. A. Durnin

1. The intake and excretion of total nitrogen, fat and the various forms of carbohydrate, and the heats of combustion of the diet, urine and faeces were measured in groups of young men, young women, elderly men and elderly women.2. Each group was studied while the subjects were eating two diets in turn, which differed in their contents of unavailable carbohydrate; the young women were also studied on a third diet which was rich in unavailable carbohydrate.3. Increasing the intake of unavailable carbohydrate resulted in a greater faecal loss of energy, and in most instances of nitrogen and fat.4. There was no significant effect of sex or age on the apparent digestibility of protein, fat or available carbohydrate.5. The results are used to evaluate the use of calorie conversion factors for calculating the metabolizable energy content of mixed diets.6. These show that for practical purposes the classical Atwater factors can be used to calculate the metabolizable energy of a diet with reasonable accuracy, provided that when available carbohydrate (as monosaccharides) values are used in the calculation a factor of 3.75 kcal/g (15.7 kJ/g) is used.7. The studies demonstrate that the accuracy of any method for calculating the metabolizable energy of a diet is largely determined by the accuracy with which the method is capable of predicting the gross energy of the diet.


1995 ◽  
Vol 74 (3) ◽  
pp. 289-302 ◽  
Author(s):  
G. Livesey ◽  
T. Smith ◽  
B. O. Eggum ◽  
I. H. Tetens ◽  
M. Nyman ◽  
...  

The performance of methods to determine energy conversion factors for dietary fibre (DF) supplements and fermentability (D) values of their non-starch polysaccharides (NSP) was investigated. Heats of combustion, digestible energy (DE) and D values were determined on five DF supplements in five European laboratories on five separate occasions. In each instance the DF supplements were fed to juvenile male VVistar rats at two doses, 50 and 100 g/kg basal diet, for 3 weeks with food and faeces collected in the 3rd week. Among-laboratory variations in heats of combustion (DHC<) were <2%. DE values (kJ/g dry weight) at the upper and lower doses respectively were: 10·4 and 9·9 for a high-methoxyl apple pectin, 9·5 and 9·4 for a sugar-beet DF supplement, 12·2 and 12·7 for soyabean DF supplement, 38 and 4·0 for maize bran, and 0·3 and 0·3 for Solka-floc cellulose. Variations among laboratories, among occasions and among animals were <1, <2 and <2·5 kJ/g respectively. The among-occasion: among-laboratory variance ratio for DE was 0·5, suggesting the method performed equally well in all laboratories. There was no evidence of learning or fatigue in the performance of the method. D values were also independent of dose and at the high and lower doses were: pectin 0·92 and 0·95, sugar-beet NSP 0·68 and 0·68, soyabean NSP 0·86 and 0·88, maize bran 0·17 and 0·18, cellulose 0·07 and 0·06. Among-laboratory variance tended to increase with decreasing fermentability and ranged from 0·03 to 0·18. The DE and D data were not significantly different from a previously proposed relationship DE = 0·7 × DHc × D, where DHc is the heat of combustion of the supplement. We conclude that while the among-laboratory variation in the D of difficult-to-ferment NSP is too large for the reliable prediction of energy value the method for the direct determination of DE is both reproducible and repeatable, that DE is independent of dosage of DF supplement up to 100 g/kg diet, and that it is safe to discriminate between energy values with a precision of 3 kJ/g. The conversion of both DE and D to net metabolizable energy for the purpose of food labelling, tables and databases is described.


2016 ◽  
Vol 67 (3) ◽  
pp. 121-131
Author(s):  
Martin Gierus ◽  
Birgit Eickler ◽  
Reinhard Resch ◽  
Ralf Loges ◽  
Friedhelm Taube ◽  
...  

SummaryTwoin vitromethods were tested to establish their potential to predict the metabolizable energy (ME) content of forage legumes: the Tilley and Terry (TT) method and the pepsin-cellulase method (CM). Different samples of white clover (Trifolium repensL.), red clover (Trifolium pratenseL.), kura clover (Trifolium ambiguumM. Bieb.), lucerne (Medicago sativaL.), and birdsfoot trefoil (Lotus corniculatusL.) were derived from field trials with several defoliation systems at two sites. The CM was more precise due to its repeatability within and between analysis runs, but eventually overestimated the ME contents of the samples, as it was shown for the standard samples with knownin vivodigestibility. ME contents were found to be consistently higher based on CM, with a difference of up to 1.5 MJ ME/kg DM compared to TT. Although white clover was, in general, the species with the highest ME content, the influence of legume species over all cuts and defoliation systems was inconsistent. Such observations may influence the method of choice for ME estimation for large datasets.


1996 ◽  
Vol 1996 ◽  
pp. 41-41
Author(s):  
A.T. Adesogan ◽  
E. Owen ◽  
D.I. Givens

Estimates of the metabolisable energy (ME) content of whole crop wheat (WCW) derived using measured energy losses as methane (ELMm) are lacking due to the cost of measuring ELMm. Published ME values of WCW are largely calculated using predicted energy losses as methane (ELMp, Blaxter and Clapperton, 1965) or digestible organic matter content (DOMD) in vivo. However, there appears to be no published information about the accuracy with which DOMD in vivo or ELMp predicts the ME content of WCW. Therefore, this study assessed the validity of such ME predictions by comparing them with ME contents calculated using ELMm.


2014 ◽  
Vol 84 (5-6) ◽  
pp. 244-251 ◽  
Author(s):  
Robert J. Karp ◽  
Gary Wong ◽  
Marguerite Orsi

Abstract. Introduction: Foods dense in micronutrients are generally more expensive than those with higher energy content. These cost-differentials may put low-income families at risk of diminished micronutrient intake. Objectives: We sought to determine differences in the cost for iron, folate, and choline in foods available for purchase in a low-income community when assessed for energy content and serving size. Methods: Sixty-nine foods listed in the menu plans provided by the United States Department of Agriculture (USDA) for low-income families were considered, in 10 domains. The cost and micronutrient content for-energy and per-serving of these foods were determined for the three micronutrients. Exact Kruskal-Wallis tests were used for comparisons of energy costs; Spearman rho tests for comparisons of micronutrient content. Ninety families were interviewed in a pediatric clinic to assess the impact of food cost on food selection. Results: Significant differences between domains were shown for energy density with both cost-for-energy (p < 0.001) and cost-per-serving (p < 0.05) comparisons. All three micronutrient contents were significantly correlated with cost-for-energy (p < 0.01). Both iron and choline contents were significantly correlated with cost-per-serving (p < 0.05). Of the 90 families, 38 (42 %) worried about food costs; 40 (44 %) had chosen foods of high caloric density in response to that fear, and 29 of 40 families experiencing both worry and making such food selection. Conclusion: Adjustments to USDA meal plans using cost-for-energy analysis showed differentials for both energy and micronutrients. These differentials were reduced using cost-per-serving analysis, but were not eliminated. A substantial proportion of low-income families are vulnerable to micronutrient deficiencies.


Author(s):  
I. F. Gorlov ◽  
A. A. Mosolov ◽  
G. V. Komlatskiy ◽  
M. A. Nesterenko ◽  
K. D. Nimbona ◽  
...  

The article presents materials on the study of the possibility of reproduction and increase in the herd of highly productive cows through the use of embryo transplantation technology. The classical (in vivo) and more modern, developing (in vitro) methods of embryotransfer, their positive and negative sides are considered in detail. The possibility of accelerating the breeding process by using the method of transplantation, in which from one cow can be obtained from 10 to 100 calves, which will allow for 4-5 years, almost any herd (of any size and breed) with the help of biotechnology to turn into a cattle-breeding enterprise of the most modern level. At the same time, heifers obtained from unproductive cows can be used as "surrogate" mothers who are transplanted with the best donor embryos, which allows to obtain a full-fledged offspring adapted to local environmental conditions. A detailed scheme of obtaining, evaluation, storage, as well as the cost and economic effect of embryo transplantation was calculated, the market was evaluated, the required annual volume of transplants and the number of donor cows for large livestock farms were determined. As a positive example of "Scientific-production enterprise "Centre of biotechnology and embryo transfer" in 2014, implemented a project for accelerated replacement and genetic improvement of the dairy herd, engraftment averaged 57-69%, and the economic effect of the enterprise from getting a single animal by the method of embryo transfer, compared with imports of similar close in quality, ranged from 60 to 100 thousand rubles on his head. It is shown that it is necessary to organize at the state level a developed service for embryo transplantation to reduce the cost of embryo transfer and the possibility of creating in a short time in the country's own highly productive breeding nucleus of dairy and beef cattle, which will reduce, and in the future completely eliminate, import dependence on cattle products.


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