The relative value of concentrates and roughage for fattening cattle

1971 ◽  
Vol 13 (4) ◽  
pp. 569-579 ◽  
Author(s):  
D. Levy ◽  
Z. Holzer
Keyword(s):  
Research Council ◽  
Agricultural Research ◽  
Energy Content ◽  
National Research Council ◽  
Energy System ◽  
Metabolizable Energy ◽  
Equal Weight ◽  
Net Energy ◽  
Agricultural Research Council ◽  
Daily Gain

SUMMARYIn three similar experiments, 2 or 3 kg of a commercial concentrate mixture, forming part of a high concentrate ration, were replaced by an equal weight of dry matter of one of four roughages: hay, straw, silage and green soilage.The metabolizable energy content of the concentrate was 2-4 Mcal/kg. Expected daily gain was calculated according to the following energy systems: Scandinavian feed units (SFU), starch equivalent (SE), total digestible nutrients (TDN), the U.K. Agricultural Research Council system (ARC), and the U.S. National Research Council net energy system (NRC).The replacement of 2 kg of concentrate significantly reduced daily gain only in the straw treatment. Reduction of the fat content of the carcasses was significant for all roughage treatments. The differences between the observed daily gain and the expected, as calculated by the SFU, SE and NRC systems, were highly significant, while those between the observed and those cal culated by the TDN and ARC systems were not significant. The TDN system overestimated the nutritional value of the roughages, while the SFU and SE systems underestimated it.

A new net energy system for ruminants

1974 ◽  
Vol 19 (2) ◽  
pp. 141-148 ◽  
Author(s):  
J. Harkins ◽  
R. A. Edwards ◽  
P. Mcdonald
Keyword(s):  
Linear Programming ◽  
Research Council ◽  
Agricultural Research ◽  
Energy System ◽  
Metabolizable Energy ◽  
Net Energy ◽  
Iterative Approach ◽  
Agricultural Research Council ◽  
Growing Cattle

SUMMARYA simplified Net Energy system for ruminants is described. It is based on the Metabolizable Energy system outlined by the Agricultural Research Council (1965) and enables a non-iterative approach to be used in the formulation of rations. The method is suitable for use in linear programming work and is illustrated, with appropriate tables, for growing cattle.

Protein and energy requirements and responses : a United States perspective

1995 ◽  
Vol 19 ◽  
pp. 43-50
Author(s):  
L. D. Satter ◽  
T. R. Dhiman
Keyword(s):  
Milk Production ◽  
Research Council ◽  
Agricultural Research ◽  
National Research Council ◽  
Protein Supplementation ◽  
Metabolizable Energy ◽  
Net Energy ◽  
Food Protein ◽  
Response Curves ◽  
Agricultural Research Council

AbstractA comparison of UK (Agricultural Research Council; ARC) and USA (National Research Council; NRC) feeding standards for dairy cows is made. The two standards appear similar in terms of food energy required for milk production, even though the ARC uses metabolizable energy and the NRC uses net energy. The two systems have the same basic approach to calculating protein supply, although ARC incorporates information on level of food intake in calculating rumen microbial protein synthesis and in estimating undegraded food protein. The maintenance requirement for protein is much less with the ARC system because NRC assigns a large maintenance charge to metabolic faecal nitrogen. The result is that ARC has lower dietary protein recommendations than NRC. Milk production response to incremental additions of energy (grain) or protein diminishes as the point of maximum response is approached. The most profitable level of energy and/or protein supplementation is often below the supplementation level required for maximum milk production. More emphasis must be given to lactation studies for information to improve accuracy of the feeding standards and for construction of milk response curves to incremental additions of supplements.

The nutritive value for ruminants of a complete processed diet based on barley straw

1970 ◽  
Vol 74 (2) ◽  
pp. 311-314 ◽  
Author(s):  
F. W. Wainman ◽  
K. L. Blaxter ◽  
J. D. Pullar
Keyword(s):  
Organic Matter ◽  
Research Council ◽  
Nutritive Value ◽  
Agricultural Research ◽  
Nitrogen Retention ◽  
Metabolizable Energy ◽  
Barley Straw ◽  
Energy Value ◽  
Agricultural Research Council

SUMMARYCalorimetric experiments were made with a complete extruded diet for ruminants, ‘Ruminant Diet A’ prepared by Messrs U.K. Compound Feeds Ltd. Twelve determinations of energy and nitrogen retention were made using sheep and it was found that the diet had a metabolizable energy value of 2–32 kcal/g organic matter, and the net availabilities of its metabolizable energy were 42–7 % for fattening and 68–0 % for maintenance. These values agreed well with those predicted from equations published by the Agricultural Research Council. On a dry basis the starch equivalent was 38–3 %.

The me system : The biological basis

1986 ◽  
Vol 1986 ◽  
pp. 60-60
Author(s):  
D.J. Thomson ◽  
M.J. Haines ◽  
S.B. Cammell ◽  
M.S. Dhanoa
Keyword(s):  
Research Council ◽  
Agricultural Research ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Nutrient Requirements ◽  
Animal Performance ◽  
Biological Basis ◽  
Additional Information ◽  
Agricultural Research Council ◽  
New System

The Starch Equivalent (SE) system devised by Kellner for expressing the energy requirements of ruminants and the energy value of feeds was used in Britain from 1912. Metabolizable energy (ME) was proposed (Agricultural Research Council, 1965) and adopted (MAFF, DAFS and DANI, Technical Bulletin 33, 197S), as a basis for a new system relating diet to the energy requirements of animals. Additional information was incorporated in the extensive Technical Review (The Nutrient Requirements of Ruminant Livestock, 1980). Metabolizable energy was retained, and animal performance it was claimed, was predicted more precisely with ME than SE. Results presented in this paper are for the comparison, and interpretation, of observed and predicted (Technical Bulletin 33) rates of gain, and other components of the ME system, for growing lambs and cattle fed forage and mixed forage and concentrate diets.

Energy and protein utilization for maintenance and growth in Omani ram lambs in hot climates. I. Estimates of energy requirements and efficiency

2001 ◽  
Vol 136 (4) ◽  
pp. 451-459 ◽  
Author(s):  
R. J. EARLY ◽  
O. MAHGOUB ◽  
C. D. LU
Keyword(s):  
Research Council ◽  
Geometric Mean ◽  
National Research Council ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Maximum Temperature ◽  
Net Energy ◽  
Linear Quadratic ◽  
Temperate Climates

Energy requirements for maintenance and growth were estimated by comparative slaughter in Omani male lambs during the hot summer months (July–October: maximum temperature, 48 °C). Weaned lambs (n = 10 per diet) were fed one of three totally mixed, 160 g CP/kg DM diets that contained 600, 400 or 200 g rhodesgrass hay/kg for low (9·98 MJ/kg, medium (10·3 MJ/kg) and high (11·4 MJ/kg) energy contents, respectively. All diets were balanced to meet the minimum nutritional needs for maximum growth. The trial lasted for 113–114 days. The purpose of having three diets was to induce a broad spectrum of growth rates that could be used in regression analysis (tested for linear, quadratic and exponential effects). Metabolizable energy (ME) intake was regressed on live weight (LW), empty body weight, tissue energy and tissue protein gain and vice versa. Coefficients of determinations were not significantly improved by quadratic or logarithmic regressions over linear relationships. Geometric mean regressions were used to control further biases due to major axis dependence when Y is regressed on X or vice versa. Based on tissue energy gain, the best estimates of ME required for maintenance (MEm) and gain (MEg) were 526 kJ/kg LW0·75/d and 42·1 kJ/kg LW0·75/g LW gain, respectively. Net energy values for maintenance (NEm) and gain (NEg) were 278 kJ/kg LW0·75/d and 20·6 kJ/kg LW0·75/g LW gain, respectively. These equations predicted MEm and NEm requirements that were similar to or slightly greater than those established by the US National Research Council (1985) and the UK Agricultural and Food Research Council (1993) for growing male lambs. The MEg and NEg requirements were substantially greater (by 43–89%) in this respect. Efficiency values were calculated as net energy available for maintenance or gain divided by the metabolizable energy available for maintenance or gain. The efficiency of metabolizable energy used for maintenance and gain was 0·50 and 0·52, respectively, and did not appear to be much different from values for other breeds of sheep in temperate climates. Dietary energy concentrations did not affect the efficiency of energy deposition. The data suggest that Omani sheep in hot climates have greater NEg requirements, and consequently MEg requirements, than other breeds of sheep in temperate climates.

scholarly journals How did Lofgreen and Garrett do the math?

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.

Evaluation of the National Research Council (NRC) nutrient requirements for beef cattle: Predicting feedlot performance

2003 ◽  
Vol 83 (4) ◽  
pp. 787-792
Author(s):  
E. K. Okine ◽  
D. H. McCartney ◽  
J. B. Basarab
Keyword(s):  
Beef Cattle ◽  
Dry Matter ◽  
Research Council ◽  
Average Daily Gain ◽  
National Research Council ◽  
Metabolizable Energy ◽  
Dry Matter Intake ◽  
Net Energy ◽  
Feeder Cattle

The accuracy of predicted CowBytes® versus actual dry matter intake (DMI) and average daily gain (ADG) of 407 Hereford × Angus and Charolais × Maine Anjou (445.6 ± 36 kg) feeder cattle using digestable enery acid detergent fiber (DE) estimated from the (ADF) content [Laboratory analysis method (LAB)] and from values determined in vivo (INVIVO method) was examined. The diet consisted of a 73.3% concentrate diet, 22.0% barley silage, 1.6% molasses, and 3.1% feedlot supplement fed ad libitum (as-fed basis). The calculated DE values of the feed were used to predict the metabolizable energy (ME), net energy of maintenance (NEm), and net energy of gain (NEg) of the diet. These energy values were then used in CowBytes® to predict dry matter intake (DMI), ADG, and days on feed (DOF) necessary to meet targeted quality grade of AA and weights of 522 and 568 kg for the heifers and steers, respectively. There was no effect of gender and prediction method interaction (P > 0.10) on any of the variables measured. There were no (P > 0.05) differences in predicted DMI by either the INVIVO or LAB method but both methods underestimated DMI actually consumed by the cattle by 6.8 and 4.9% (P = 0.007), respectively. Indeed, regression values from these predictive methods and actual DMI were (P < 0.05) different from the one-to-one relationship expected by definition. In spite of the higher actual DMI, the actual ADG of the cattle was 14 and 11% (P = 0.0004) lower than was predicted by either the INVIVO or LAB methods. A possible reason for the lower ADG could be an overestimation of DE of the diet. Thus, if available, users of CowBytes® should use actual DMI from their experience in ration formulation. In addition, the effects of environmental temperature on digestibility of diets should be taken into consideration when using the DE of the diet as determined from in vivo digestibility trials or calculated from chemical analyses in determining the DMI of feedlot cattle. Key words: Beef cattle, performance, CowBytes®, National Research Council

AN EVALUATION OF TOTAL DIGESTIBLE NUTRIENTS, METABOLIZABLE ENERGY, AND NET ENERGY FOR THE PREDICTION OF ENERGY REQUIREMENTS FOR BEEF CATTLE IN ONTARIO

1973 ◽  
Vol 53 (3) ◽  
pp. 471-477
Author(s):  
D. I. DICKIE ◽  
J. W. WILTON ◽  
T. D. BURGESS
Keyword(s):  
Beef Cattle ◽  
Research Council ◽  
National Research Council ◽  
Domestic Animals ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Net Energy ◽  
Nutrient Requirements ◽  
National Academy Of Sciences ◽  
Academy Of Sciences

Four studies and populations of beef animals were used to evaluate different methods of expressing energy requirements by comparing actual to predicted gains of bulls and steers fed in Ontario. Large differences between predicted and actual gains occurred. Based on a total of 503 animals, gains predicted by the net energy method (National Academy of Sciences–National Research Council. 1970. Nutrient requirements of domestic animals. 4. Nutrient requirements of beef cattle. (4th rev.). Nat. Acad. Sci., Publ. ISBN 0-309-01754-8; Washington, D.C.) were approximately 20% below the actual gains but exceptions within treatment groups were evident. Three hundred and twenty-five individually fed bulls were used to compare the accuracy with which gains were predicted from equations using total digestible nutrients (National Academy of Sciences–National Research Council. 1963. Nutrient requirements of domestic animals. 4. Nutrient requirements of beef cattle. Nat. Acad. Sci., Publ. 1137, Washington, D.C.) net energy (National Academy of Sciences–National Research Council. 1970. Nutrient requirements of domestic animals. 4. Nutrient requirements of beef cattle. (4th rev.). Nat. Acad. Sci., Publ. ISBN 0-309-01754-8, Washington, D.C), and metabolizable energy (Agricultural Research Council. 1965. The nutrient requirements of farm animals. No. 2. Ruminants. London, England). The metabolizable energy method predicted gains most accurately.

A study of the energy requirements of weaned lambs

1969 ◽  
Vol 11 (3) ◽  
pp. 389-397 ◽  
Author(s):  
T. J. Forbes ◽  
J. J. Robinson
Keyword(s):  
Organic Matter ◽  
Research Council ◽  
Agricultural Research ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Feeding Level ◽  
Agricultural Research Council ◽  
Digestible Organic Matter ◽  
High Level

SUMMARYTwo experiments were carried out to study the energy requirements of young fattening lambs for maintenance and production. Forty weaned lambs were used in each experiment, 20 being allocated to a high level of feeding (900 g air-dry feed per day) and 20 to a low level (540 g). The animals used in Experiment 1 were approximately 12 months of age and their mean live weight was 35·3±4·03 kg. Those in Experiment 2 were approximately seven months of age and their mean live weight was 36·7 ± 4·57 kg. Experiment 1 continued for 100 days and Experiment 2 for 47 days. Three digestibility trials, involving three animals from each feeding level, were carried out during the course of each experiment to obtain precise estimates of digestible organic matter intake (DOMI). The estimated mean DOMI required for maintenance for a 45-kg lamb was 400 g (0·88 lb) or 1500 kcal metabolizable energy per day. The estimated maintenance requirement was not affected by the age of the animal. The DOMI required for production ranged from 1·55 kg per kg live-weight gain for the younger animals to 1·71 kg for the older animals. Both these requirements were lower than those obtained by other workers and those suggested by the Agricultural Research Council (1965).

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