The digestible energy, metabolizable energy, and net energy content of dietary fat sources in thirteen- and fifty-kilogram pigs1

AbstractTwo experiments were conducted to measure rates of ruminal disappearance, and energy and nutrient availability and N balance among cows fed corn husks, leaves, or stalks. Ruminal disappearance was estimated after incubation of polyester bags containing husks, leaves or stalks in 2 separate ruminally cannulated cows in a completely randomized design. Organic matter (OM) that initially disappeared was greatest for stalks and least for husks and leaves (P < 0.01), but amounts of NDF that initially disappeared was greatest for husks, intermediate for stalks, and least for leaves (P < 0.01). Amounts of DM and OM that slowly disappeared were greatest in husks, intermediate in leaves, and least in stalks (P < 0.01). However, amounts of NDF that slowly disappeared were greatest in leaves, intermediate in husks, and least in stalks (P < 0.01). Rate of DM and OM disappearance was greater for leaves, intermediate for husks and least for stalks, but rate of NDF disappearance was greatest for stalks, intermediate for leaves, and least for husks (P < 0.01). Energy and nutrient availability in husks, leaves, or stalks were measured by feeding ruminally cannulated cows husk-, leaf-, or stalk-based diets in a replicated Latin square. Digestible energy lost as methane was less (P = 0.02) when cows were fed leaves in comparison to husks or stalks, and metabolizable energy (Mcal/kg DM) was greater (P = 0.03) when cows were fed husks and leaves compared with stalks. Heat production (Mcal/d) was not different (P = 0.74) between husks, leaves, or stalks; however, amounts of heat produced as a proportion of digestible energy intake were less (P = 0.05) among cows fed leaves in comparison to stalks or husks. Subsequently, there was a tendency (P = 0.06) for net energy available for maintenance from leaves (1.42 Mcal/kg DM) to be greater than stalks (0.91 Mcal/kg DM), and husks (1.30 Mcal/kg DM) were intermediate. Nitrogen balance was greater when cows were fed leaves, intermediate for husks, and least for stalks (P = 0.01). Total tract digestion of NDF was greater (P < 0.01) for husks and leaves compared with stalks. Husks had greater (P = 0.04) OM digestibility in comparison to stalks, and leaves were intermediate. Apparently, greater production of methane from husks in comparison to leaves limited amounts of energy available for maintenance from husks even though total-tract nutrient digestion was greatest when cows were fed husks or leaves.

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Energy content of intact and heat-treated dry extruded-expelled soybean meal fed to growing pigs

Journal of Animal Science ◽

10.1093/jas/skab131 ◽

2021 ◽

Author(s):

Bonjin Koo ◽

Olumide Adeshakin ◽

Charles Martin Nyachoti

Keyword(s):

Heat Production ◽

Soybean Meal ◽

Energy Content ◽

Basal Diet ◽

Growing Pigs ◽

Metabolizable Energy ◽

Energy Utilization ◽

Experimental Unit ◽

Net Energy ◽

Heat Treated

Abstract An experiment was performed to evaluate the energy content of extruded-expelled soybean meal (EESBM) and the effects of heat treatment on energy utilization in growing pigs. Eighteen growing barrows (18.03 ± 0.61 kg initial body weight) were individually housed in metabolism crates and randomly allotted to one of three dietary treatments (six replicates/treatment). The three experimental diets were: a corn-soybean meal-based basal diet and two test diets with simple substitution of a basal diet with intact EESBM or heat-treated EESBM (heat-EESBM) at a 7:3 ratio. Intact EESBM was autoclaved at 121°C for 60 min to make heat-treated EESBM. Pigs were fed the experimental diets for 16 d, including 10 d for adaptation and 6 d for total collection of feces and urine. Pigs were then moved into indirect calorimetry chambers to determine 24-h heat production and 12-h fasting heat production. The energy content of EESBM was calculated using the difference method. Data were analyzed using the Mixed procedure of SAS with the individual pig as the experimental unit. Pigs fed heat-EESBM diets showed lower (P < 0.05) apparent total tract digestibility of dry matter (DM), gross energy, and nitrogen than those fed intact EESBM. A trend (P ≤ 0.10) was observed for greater heat increments in pigs fed intact EESBM than those fed heat-EESBM. This resulted in intact EESBM having greater (P < 0.05) digestible energy (DE) and metabolizable energy (ME) contents than heat-EESBM. However, no difference was observed in net energy (NE) contents between intact EESBM and heat-EESBM, showing a tendency (P ≤ 0.10) toward an increase in NE/ME efficiency in heat-EESBM, but comparable NE contents between intact and heat-EESBM. In conclusion, respective values of DE, ME, and NE are 4,591 kcal/kg, 4,099 kcal/kg, and 3,189 kcal/kg in intact EESBM on a DM basis. It is recommended to use NE values of feedstuffs that are exposed to heat for accurate diet formulation.

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How did Lofgreen and Garrett do the math?

Translational Animal Science ◽

10.1093/tas/txz072 ◽

2019 ◽

Vol 3 (3) ◽

pp. 1011-1017

Author(s):

James W Oltjen

Keyword(s):

Body Weight ◽

Energy Content ◽

Energy System ◽

Metabolizable Energy ◽

Net Energy ◽

Significant Difference ◽

Linear Fit ◽

Metabolizable Energy Intake ◽

Logarithmic Equation ◽

Finishing Beef Cattle

Abstract Lofgreen and Garrett introduced a new system for predicting growing and finishing beef cattle energy requirements and feed values using net energy concepts. Based on data from comparative slaughter experiments they mathematically derived the California Net Energy System. Scaling values to body weight to the ¾ power, they summarized metabolizable energy intake (ME), energy retained (energy balance [EB]), and heat production (HP) data. They regressed the logarithm of HP on ME and extended the line to zero intake, and estimated fasting HP at 0.077 Mcal/kg0.75, similar to previous estimates. They found no significant difference in fasting HP between steers and heifers. Above maintenance, however, a logarithmic fit of EB on ME does not allow for increased EB once ME is greater than 340 kcal/kg0.75, or about three times maintenance intake. So based on their previous work, they used a linear fit so that partial efficiency of gain above maintenance was constant for a given feed. They show that with increasing roughage level efficiency of gain (slope) decreases, consistent with increasing efficiency of gain and maintenance with greater metabolizable energy of the feed. Making the system useful required that gain in body weight be related to EB. They settled on a parabolic equation, with significant differences between steers and heifers. Lofgreen and Garrett also used data from a number of experiments to relate ME and EB to estimate the ME required for maintenance (ME = HP) and then related the amount of feed that provided that amount of ME to the metabolizable energy content of the feed (MEc), resulting in a logarithmic equation. Then they related that amount of feed to the net energy for gain calculated as the slope of the EB line when regressed against feed intake. Combining the two equations, they estimate the net energy for maintenance and gain per unit feed (Mcal/kg dry matter) as a function of MEc: 0.4258 × 1.663MEc and 2.544–5.670 × 0.6012MEc, respectively. Finally, they show how to calculate net energy for maintenance and gain from experiments where two levels of a ration are fed and EB measured, where one level is fed and a metabolism trial is conducted, or when just a metabolism trial is conducted—but results are not consistent between designs.

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Determination of the yield characteristics and in vitro digestibility of barley forage harvested in different vegetation periods

Indian Journal of Animal Research ◽

10.18805/ijar.9365 ◽

2016 ◽

Author(s):

Mehtap Guney ◽

Cagri Kale ◽

Duran Bolat ◽

Suphi Deniz

Keyword(s):

Organic Matter ◽

Dry Matter ◽

Energy Content ◽

Vegetation Period ◽

Metabolizable Energy ◽

Mature Stage ◽

In Vitro Digestibility ◽

Net Energy ◽

Seed Formation

This study planned to determine the differences among nutrient composition, in vitro digestibility, energy content, digestible dry matter and organic matter yields of barley forage harvested at three different stages of maturity. Each vegetation period (heading stage, seed formation stage and mature stage) was randomly assigned to 5 replication from 1 square meter area and fifteen samples were harvested in total. DM, ADF (p<0.001), and NDF (p<0.05) contents were different in each stages of barley forage. In vitro dry matter (IVDMD), organic matter digestibility (IVOMD), metabolizable energy (ME), and net energy for lactation (NEL) values of samples were determined to be lower than the other two stages at the mature stage (p<0.05). Yield parameters of barley were significantly affected by vegetation period (p<0.001). It can be concluded that all three vegetation period had significantly higher digestibility. Digestible DM, OM and energy yields were higher when harvested at the mature stage of vegetation.

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The utilization of the dietary energy of pangola and setaria by young growing beef cattle

The Journal of Agricultural Science ◽

10.1017/s0021859600041940 ◽

1982 ◽

Vol 98 (2) ◽

pp. 395-404 ◽

Cited By ~ 7

Author(s):

G. D. Tudor ◽

D. J. Minson

Keyword(s):

Protein Content ◽

Dry Matter ◽

Production Systems ◽

Energy Content ◽

Live Weight ◽

Initial Energy ◽

Metabolizable Energy ◽

Net Energy ◽

Lower Efficiency ◽

Tropical Grasses

SUMMARYThe net energy values for growth and fattening of two artificially dried tropical grasses-, pangola (Digitaria decumbens) and setaria (S. sphacelata var. sericea cv. Nandi), of similar estimated metabolizable energy content (8·07 and 7·96 MJ/kg D.M.) were determined with cattle using a slaughter technique. Growing cattle with a mean initial weight of 175 kg were given equal quantities of dry matter of the two grasses at each of three planes of nutrition above maintenance for a period of 152 days.The initial energy, fat and protein content of the total body of the 24 test animals was estimated from regressions relating fasted live weight to theśe components, derived from 12 similar cattle slaughtered at the beginning of the feeding period. The final energy, fat and protein content of the test animals was determined directly by chemical analysis. The metabolizable energy (ME) content of the grasses was estimated from the level of digestible energy (DE) determined with eight cattle, assuming that ME = 0·815 DE.The cattle fed pangola gained more live weight, empty-body weight, fat, protein and energy than animals fed similar quantities of setaria. The net energy value for growth and fattening (NEf) was determined using regressions relating energy retention to the quantity of dry matter eaten. NEf in MJ/kg dry matter was 2·27 for pangola and 1·31 for setaria.Efficiency of utilization of ME for growth and fattening (kf) was.27·7% for pangola and 16·9% for setaria. These values for tropical grasses are lower than any values reported for temperate pasture species. Thus the lower efficiency of utilization of ME may cause the lower production of cattle which graze tropical grasses.It was concluded that as the kf values of different tropical grasses are not constant, kf values should be measured on a wider range of tropical grasses so that this factor can be taken into account when evaluating grasses in animal production systems.

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Metabolizable energy and net energy content of corn, wheat bran, soybean meal, fish meal and soybean oil for broilers

Scientia Agropecuaria ◽

10.17268/sci.agropecu.2020.03.05 ◽

2020 ◽

Vol 11 (3) ◽

pp. 335-344

Author(s):

Juan Moscoso-Muñoz ◽

Oscar Gomez-Quispe ◽

Victor Guevara-Carrasco

Keyword(s):

Soybean Oil ◽

Wheat Bran ◽

Soybean Meal ◽

Fish Meal ◽

Energy Content ◽

Metabolizable Energy ◽

Net Energy

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The net energy value of three subtropical forages

Australian Journal of Agricultural Research ◽

10.1071/ar9670137 ◽

1967 ◽

Vol 18 (1) ◽

pp. 137 ◽

Cited By ~ 11

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%).

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Estimating digestible energy values of feeds and diets and integrating those values into net energy systems

Translational Animal Science ◽

10.1093/tas/txy119 ◽

2018 ◽

Vol 3 (3) ◽

pp. 953-961 ◽

Cited By ~ 4

Author(s):

William P Weiss ◽

Alexander W Tebbe

Keyword(s):

Energy System ◽

Metabolizable Energy ◽

Neutral Detergent Fiber ◽

Net Energy ◽

Nutrient Analysis ◽

Digestible Energy ◽

Important Variation ◽

Negative Effect ◽

Gross Energy

Abstract The California Net Energy System (CNES) used a combination of measured and tabular metabolizable energy (ME) values and changes in body composition gain to determine net energy requirements for maintenance and gain and their corresponding dietary concentrations. The accuracy of the CNES depends on the accuracy of the feed ME values. Feed or diet ME values can be measured directly but are expensive and require specialized facilities; therefore, most ME values are estimated from digestible energy (DE) values, which are often estimated from the concentration of total digestible nutrients (TDN). Both DE and TDN values are often from tables and not based on actual nutrient analysis. The use of tabular values eliminates important within-feed variation in composition and digestibility. Furthermore, the use of TDN to estimate DE does not account for important variation in the gross energy value of feeds. A better approach would be to estimate DE concentration directly from nutrient composition or in vitro (or in situ) digestibility measurements. This approach incorporates within-feed variation into the energy system and eliminates the issues of using TDN. A widely used summative equation based on the commonly measured feed fractions (ash, crude protein, neutral detergent fiber, and fat) has been shown to accurately estimate DE concentrations of many diets for cattle; however, deficiencies in that equation have been identified and include an overestimation of DE provided by fat and an exaggerated negative effect of intake on digestibility. Replacing the nonfiber carbohydrate term (which included everything that was not measured) in the equation with measured starch concentration and residual organic matter (i.e., nonfiber carbohydrate minus starch) should improve accuracy by accounting for more variation in starch digestibility. More accurate estimates of DE will improve the accuracy of ME values, which will ultimately lead to more accurate NE values.

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Efficiency of energy utilization in cattle given food ad libitum: predictions according to the ARC system and practical consequences

Animal Science ◽

10.1017/s0003356100007480 ◽

1994 ◽

Vol 59 (1) ◽

pp. 43-47 ◽

Cited By ~ 22

Author(s):

B. J. Tolkamp ◽

J. J. M. H. Ketelaars

Keyword(s):

Energy Intake ◽

Agricultural Research ◽

Energy Content ◽

Live Weight ◽

Metabolizable Energy ◽

Energy Utilization ◽

Net Energy ◽

Ad Libitum ◽

Overall Efficiency ◽

Diet Type

AbstractOverall efficiency of energy utilization (i.e. total net energy intake as a fraction of metabolizable energy intake) in cattle given food ad libitum was calculated from information included in the United Kingdom energy evaluation system as published by the Agricultural Research Council. For growing cattle (live weight 250 kg), overall efficiency was estimated for five levels of diet metabolizability (ranging from q = 0·45 to q = 0·65) for each of two diet types: coarse/long roughage and fine/pelleted diets. The overall efficiencies varied from 0·58 to 0·62 and were not systematically affected by diet type or diet metabolizability. For lactating cattle (live weight 600 kg), overall efficiency was also calculated for five diets with metabolizability ranging from 0·45 to 0·65. Calculations were made for cows at equilibrium intake (i.e. zero energy balance) and at milk production levels proportionately 0·30 higher or lower than those attained at equilibrium intake. Overall efficiencies varied from 0·60 to 0·63 and were not systematically affected by diet metabolizability.It is concluded that, in practical cattle production systems with ad libitum feeding, the net energy content of food may be estimated at 0·6 of the metabolizable energy content (or 0·5 of the digestible energy content), irrespective of diet type, diet metabolizability or productive function.

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