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).

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.

The nutritive value of silages

1978 ◽  
Vol 40 (2) ◽  
pp. 205-219 ◽  
Author(s):  
N. C. Kelly ◽  
P. C. Thomas
Keyword(s):  
Dry Matter ◽  
Research Council ◽  
Nutritive Value ◽  
Agricultural Research ◽  
Metabolizable Energy ◽  
Broad Agreement ◽  
Grass Silage ◽  
Agricultural Research Council ◽  
The Mean ◽  
High Level

1. Two calorimetric experiments were conducted to study the utilization of energy in sheep given diets of grass silage or grass silage and barley. Three silages were investigated. One was made from first-harvest grass in the spring (S) and the others from regrowth cut either early or late in the autumn (E and L respectively). All were of perennial ryegrass (Lolium perenne) and preserved with formic acid. Each silage was given at two levels of feeding, the lower providing approximately a maintenance energy intake. The S and L silages were also given supplemented with barley.2. The digestibilities of organic matter, cellulose and energy in the silages were high. Measured at maintenance, digestible energy (de) contents (MJ/kg dry matter (dm)) were 11.83, 14.67 and 12.90 for S, E and L respectively. The de contents of the S and E silages were depressed at the higher level of feeding but the effect was offset by changes in the energy losses as methane and urine. Metabolizable energy (me) contents (MJ/kg dm) for the three silages, S, E and L were respectively 9.88, 12.54 and 10.73 at the low level of feeding and 9.91, 11.99 and 11.08 at the high level of feeding. The mean me content of barley calculated by difference was 13.76 MJ/kg dm.3. The mean efficiencies of utilization of me for maintenance (km) for the S, E and L silages were 0.69, 0.71 and 0.68 respectively. Corresponding values for fattening (kf) were 0.21, 0.57 and 0.59. Excepting the kf for the S silage which was low, observed efficiencies were in broad agreement with those predicted by the equations of the Agricultural Research Council (1965). Similar agreement was obtained with all diets consisting of silage and barley.

Prediction of the Energy Requirements for Growth in Beef Cattle 1. The irrelevance of fasting metabolism

1974 ◽  
Vol 19 (2) ◽  
pp. 127-139 ◽  
Author(s):  
A. J. F. Webster ◽  
J. M. Brockway ◽  
J. S. Smith
Keyword(s):  
Energy Balance ◽  
Research Council ◽  
Agricultural Research ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Positive Energy ◽  
Agricultural Research Council ◽  
Energy Retention ◽  
Positive Energy Balance ◽  
Pelleted Diet

SUMMARY1. According to the Agricultural Research Council (1965) energy retention in cattle is predicted from metabolizable energy (ME) intake, the net availabilities of ME for maintenance (km) and for fattening (kf) and measurements made of fasting metabolism (F). The present experiments were designed to examine the validity of the use of F as a basis from which to predict energy retention.2. Four British Friesian and four Aberdeen Angus steers were fed, from weaning to slaughter at about 450 kg, a barley-based, pelleted diet at two levels calculated to yield overall efficiencies of retention of ME of 20% and 10% respectively. Successive measurements were made of the energy balance of each animal at intervals of 4 to 8 weeks.3. The metabolizability of the diet was measured for both sheep and cattle. In both species metabolizability was greater at the higher level of feeding. In sheep kf measured directly or estimated from metabolizability was 0·61.4. Measured values for F in cattle agreed closely with values given by the Agricultural Research Council.5. Basal metabolism in the growing animal (F') was predicted by extrapolation to zero intake of measurements made on animals in positive energy balance. Log F' during growth was proportional to log body weight0·73. Expressed in terms of the usual exponent of metabolic body size, F' was about 440 kJ/kg0·75 per 24 hr throughout growth. There were no major differences in F' attributable to breed or to level of food intake.6. The results indicate that F is not a good basis from which to predict energy retention in steers.

An equation, suitable for computer use, based on the ARC feeding system to determine the energy requirements of growing and fattening cattle

1972 ◽  
Vol 14 (1) ◽  
pp. 17-23 ◽  
Author(s):  
C. A. Zulberti ◽  
J. T. Reid
Keyword(s):  
Weight Gain ◽  
Computer Use ◽  
Agricultural Research ◽  
Energy Requirement ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Energy Concentration ◽  
Feeding System ◽  
Agricultural Research Council ◽  
Forward Calculation

SUMMARYBased on the Agricultural Research Council's feeding system, equations were developed that allow the calculation of the metabolizable energy requirements for maintenance and weight gain by cattle, separately or combined. A general equation was developed for the straight-forward calculation of the total metabolizable energy requirements of growing and fattening cattle for any combination of body weight, rate of weight gain, age, level of muscular work, and metabolizable energy concentration of the diet. The estimates of energy requirement made by the use of this equation are in excellent agreement with those made by the Agricultural Research Council using an iterative method.In addition to avoiding the awkward iterative process, the equations proposed are readily adaptable to computer use.

Validation of new systems for protein evaluation in ruminants by testing the effect of urea supplementation on intake and digestibility of straw with or without sodium hydroxide treatment

1978 ◽  
Vol 91 (2) ◽  
pp. 483-486 ◽  
Author(s):  
E. R. Ørskov ◽  
D. A. Grubb
Keyword(s):  
Organic Matter ◽  
Dry Matter ◽  
Research Council ◽  
Agricultural Research ◽  
Barley Straw ◽  
Protein Requirements ◽  
Agricultural Research Council ◽  
Ad Libitum ◽  
Four Levels ◽  
Sodium Hydroxide Treatment

SUMMARYMilled barley straw, either untreated or treated with 70 g of NaOH/kg straw was supplemented with four levels of urea, namely 0, 6, 12 or 18 g/kg and fed ad libitum to young sheep. For the untreated straw, dry-matter intakes were (g/day) 423, 451, 441 and 463, while the digestibility of organic matter was 458, 467, 490 and 483 g/kg, respectively. For the treated straw, the intakes of dry matter were 355, 402, 531 and 567 g/day and the digestibility of organic matter was 423, 480, 589 and 628 g/kg respectively.The different responses to urea supplementation of treated and untreated straw are discussed in relation to a new system of estimating protein requirements for ruminants put forward by the Agricultural Research Council.

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 Faecal endogenous loss of calcium in young sheep

1989 ◽  
Vol 61 (1) ◽  
pp. 59-65 ◽  
Author(s):  
J. S. Chrisp ◽  
A. R. Sykes ◽  
N. D. Grace
Keyword(s):  
White Clover ◽  
Dry Matter ◽  
Research Council ◽  
Agricultural Research ◽  
Energy Requirement ◽  
Energy Requirements ◽  
Maintenance Energy ◽  
Agricultural Research Council ◽  
The Mean ◽  
Maintenance Energy Requirement

1. Two groups of eight 6–7-month-old wether lambs were offered either a frozen ryegrass (Lolium perenne L.)-white clover (Trifolium repens L.) pasture or a ryegrass-white clover hay, containing 12.1 and 6.4 g calcium/ kg dry matter (DM) respectively. Within groups the amounts offered to individual sheep ranged from 0.5 to 2.0 times the estimated maintenance energy requirements.2. A single intravenous injection of 150 μCi 45Ca as CaCl2. 2H2O, and stable balances were used to determine absorption, faecal endogenous loss and balance of Ca.3. Faecal endogenous loss of Ca increased by 1.2 mg/kg body-weight (W) per d with each g/kg W per d increase in DM intake regardless of the diet. At any DM intake the mean faecal endogenous loss was 5.5 mg/kg W per d higher in the sheep offered the frozen herbage diet when compared with those on the hay diet. At any Ca intake the mean faecal endogenous loss was 6.9 mg/kg W higher in sheep offered the hay diet compared with those on the frozen herbage.4. At feeding levels of about 1.5–2 times the estimated maintenance energy requirement the observed faecal endogenous loss of Ca ranged from 35 to 50 mg/kg W per d, which is two- to threefold greater than the present estimate of the Agricultural Research Council (1980) of 16 mg/kg W per d.5. A simple model to explain the variation in faecal endogenous loss of Ca between the present study with young sheep and that with lactating ewes (Chrisp et al. 1989) also offered herbage diets is developed, which incorporates the concept of a true endogenous loss related to DM intake and a net endogenous loss reflecting the extent of re-absorption of Ca endogenous losses within the gastrointestinal tract.

An evaluation of prediction equations incorporated in a computer program to ration beef cattle

1988 ◽  
Vol 46 (2) ◽  
pp. 169-179 ◽  
Author(s):  
H. D. St C. Neal ◽  
M. Gill ◽  
J. France ◽  
A. Spedding ◽  
S. Marsden
Keyword(s):  
Beef Cattle ◽  
Computer Program ◽  
Agricultural Research ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Mathematical Basis ◽  
Agricultural Research Council ◽  
The Mean ◽  
Protein Supply ◽  
On Farm

AbstractEquations for the prediction of forage dry-matter intake, metabolizable energy (ME), rumen degradable protein and undegraded protein, based on those in the current Agricultural Research Council system, were incorporated into a computer program designed to be used by livestock advisors for on-farm rationing of beef cattle. The predictions of silage intake and live-weight gain are compared with experimental data.Voluntary intake of grass silage was generally over-estimated by the program by proportionately at least 0·06, with a root mean square error of ±0·18 of the mean observed silage intake for the all-silage rations. The prediction of ME requirement for observed production had an error of +0·15 of average ME intake but the calculations of ME intake were themselves dependent on the predictions of the ME concentrations of the silages and supplements. Similarly the comparison of protein supply with requirement was highly dependent on the value assigned to N-degradability. However, the program can be used to assess how changes in the input values would affect ration formulation.The mathematical basis of the program is described in the Appendix.

Responses to variations in dietary energy intakes by growing pigs 2. The effects on feed conversion efficiency of changes in level of intake above maintenance

1972 ◽  
Vol 15 (2) ◽  
pp. 117-125 ◽  
Author(s):  
J. L. Davies ◽  
I. A. M. Lucas
Keyword(s):  
Conversion Efficiency ◽  
Research Council ◽  
Agricultural Research ◽  
Daily Intake ◽  
Live Weight ◽  
Growing Pigs ◽  
Dietary Energy ◽  
Feed Conversion ◽  
Feed Conversion Efficiency ◽  
Agricultural Research Council

SUMMARYAllowances of about 1·4M, 1·8M, 2·2M, 2·6M, 3·OM, and 3·4M (M = feed required for maintenance) were compared for pigs growing over the live-weight ranges 20·40, 40·60, 60·80, and 80·100 kg, with feed conversion efficiency (FCE) as the main response criterion.Response to increased digestible energy (DE) allowance was curvilinear; FCE improved rapidly up to 2·2M-2·6M, and changed much less with intakes above 2·6M. It is concluded that optimum FCE occurs at about 2·7M for pigs of 30 kg and at about 3·OM for pigs of 50, 70 and 90 kg.Allowances of dietary DE suggested by the Agricultural Research Council correspond to 2·56M, 2·95M, 3·04M and 3·08M for pigs of 30, 50, 70 and 90 kg live weight, respectively. It appears that these are near to the optima in promoting the best FCE.Changes of −25%, −15%, −5%, +5% and +15% in daily intake around the optimum levels caused FCE to deteriorate by averages of about 13%, 4·5%, <1%, <1% and 4·5% respectively. Daily weight gains would then change by about −34%, −18%, −5%, +4% and +10%, respectively.

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