scholarly journals Energy and nitrogen intake, expenditure and retention at 32° in growing fowl given diets with a wide range of energy and protein contents

1992 ◽  
Vol 67 (2) ◽  
pp. 195-206 ◽  
Author(s):  
M. G. Macleod
Keyword(s):  
Energy Intake ◽  
Energy Cost ◽  
Diet Composition ◽  
Metabolizable Energy ◽  
Energy Concentration ◽  
Dietary Energy ◽  
Unit Energy ◽  
Wide Range ◽  
Energy Retention ◽  
Fat Diets

Heat production (HP) and the intake and retention of energy and nitrogen were measured in growing broiler fowl kept at 32° and given diets with metabolizable energy contents from 8 to 15 MJ/kg and crude protein (N × 6·25; CP) contents of 130 and 210 g/kg. The temperature of 32° was chosen for comparison with earlier measurements at 20° to minimize heat produced for the maintenance of body temperature. The effects of diet composition were observed when the same birds were taken from 20 to 32°. The tendency for energy intake to increase with dietary energy concentration was less at 32 than at 20°. The lower heat increments measured for the high-fat diets did not, therefore, confer an increased ability to sustain higher energy intake at 32°. HP was about 17% lower at 32 than at 20°; the change in HP between 20 and 32° was not significantly influenced by diet composition. The absence of significant effects of diet composition on HP, combined with the significant trend in energy intake, produced significant differences (related both to dietary energy and dietary protein concentrations) in total energy retention and in the partition of retained energy between protein and fat. As at 20°, variation in energy retention and in the composition of retained energy were the main responses to variation in dietary CP concentration and energy intake; a significantly higher energy cost of unit protein accretion on the low-CP diets was insufficient to produce an elevation in total HP because the higher unit energy cost was balanced by a lower absolute rate of protein accretion.

scholarly journals Energy and nitrogen intake, expenditure and retention at 20° in growing fowl given diets with a wide range of energy and protein contents

1990 ◽  
Vol 64 (3) ◽  
pp. 625-637 ◽  
Author(s):  
M. G. Macleod
Keyword(s):  
Energy Intake ◽  
Energy Requirement ◽  
Metabolizable Energy ◽  
Retention Efficiency ◽  
Protein Nitrogen ◽  
Body Protein ◽  
Wide Range ◽  
Energy Retention ◽  
Maintenance Energy Requirement ◽  
Diet Induced Thermogenesis

Heat production (HP) and the intake and retention of energy and nitrogen were measured at 20° in growing female broiler fowl given diets with metabolizable energy (ME) contents ranging from 8 to 15 MJ/kg at each of two crude protein (nitrogen × 6.25; CP) contents (130 and 210 g/kg). ME intake was partially controlled by the birds, but increased by 30% over the range of dietary ME concentration. CP intake varied directly with dietary CP:ME ratio, indicating that control of energy intake took priority and that food intake did not increase in order to enhance amino acid intake on low-CP diets. Maintenance energy requirement and fasting HP were not affected by diet. Although the HP of fed birds was significantly affected by dietary energy source, there was no evidence for regulatory diet-induced thermogenesis as energy intake increased. Total energy retention doubled on the higher-energy diets as a result of increased intake and retention efficiency in the absence of any compensation by diet-induced thermogenesis. The proportion of energy retained as fat was negatively correlated with dietary CP:ME ratio. It was concluded that the growing female broiler fowl responded to large differences in energy intake and dietary CP concentration not by changes in rate of energy dissipation as heat but by changes in the quantity of energy retained and in the partition of retained energy between body protein and body fat.

Energy intake regulation by layers according to diet, productivity and environment

1974 ◽  
Vol 14 (67) ◽  
pp. 133 ◽  
Author(s):  
JF Dillon
Keyword(s):  
Energy Intake ◽  
Egg Production ◽  
High Energy ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Dietary Energy ◽  
Unit Energy ◽  
Daily Energy ◽  
The Cost ◽  
Intake Regulation

The voluntary nutrient intake and productivity of White Leghorn x Australorp crossbred layers given diets ranging in metabolizable energy (M.E.) from 11.30 to 13.81 MJ kg-1 were examined to determine their ability to adjust daily energy intake. Pullets housed on deep litter and in cages had a characteristic M.E. intake of 1.35 and 1.30 MJ per bird day respectively. Pullets in deep-litter pens regulated their energy intake until the M.E. content of the diet reached 12.97 MJ kg-1 but 'overconsumed' by 7.7 per cent when the dietary energy was raised to 13.81 MJ M.E. kg-1. Caged pullets were less able to regulate energy intake and 'overconsumed' by 8.0 and 14.8 per cent when the diet contained 12.97 and 13.81 MJ M.E. kg-1 respectively. During the period of production studied it would appear to be economic to use diets of up to 12.1 3 MJ M.E. kg-1 though the optimum may be less, depending on the production situation. Productivity was not significantly altered when the protein of the diets was either reduced according to predicted 'overconsumption', or lowered to as little as 14.2 per cent when the highest energy diet was given. Savings in the cost of high energy diets may, therefore, be achieved by adjusting the protein content for 'overconsumption'. Birds offered a diet containing 13.81 MJ M.E. kg-1 for five hours per day had a productivity and efficiency of energy utilization similar to that of birds on lower energy diets ad libitum. The greater cost per unit energy of such a diet, however, militates against restricted feeding of high energy diets under field conditions. An unexpected peak in egg production and efficiency of energy utilization was observed when access to the diet with an M.E. content of 13.81 MJ kg-1 was allowed between 11.00 a.m. and 4.00 p.m. each day. The possible significance of this observation is discussed.

The utilization of dietary energy by steers during periods of restricted food intake and subsequent realimentation

1977 ◽  
Vol 88 (1) ◽  
pp. 27-33 ◽  
Author(s):  
H. P. Ledger
Keyword(s):  
Food Intake ◽  
Energy Cost ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Concentration ◽  
Standard Diet ◽  
Dietary Energy ◽  
Additional Energy ◽  
Total Distance ◽  
Daily Energy

SUMMARYAn investigation was carried out to determine the daily energy intakes necessary to maintain, the live weights of ‘maintenance-stabilized’ steers (i.e. those held at constant live weight in pens for not less than 15 weeks) when walked at 5 km/h for distances of 5, 10 and 15 km/day.The experiment utilized groups of Boran Zebu and Hereford × Boran Zebu steers at live weights of 275 and 450 kg.Fed a standard diet of energy concentration 10·477 MJ metabolizable energy (ME)/kg D.M. it was found that the Hereford × Boran steers required significantly less food per day, at both live weights, than did the Borans to maintain live weight when walking distances of 15 km/day.Based on the data relating to the total distance walked of 1120 km in 133 days it was calculated that the additional energy cost of maintaining live weight when walking was close to 4·184 kJ ME/kg/km walked. The efficiency of conversion of ME for walking was 50%.For ‘maintenance-stabilized’ steers it was calculated that the 275 kg steers required 24, 49 and 73% more daily D.M. intake and the 450 kg steers 34, 69 and 97% more daily D.M. intake when walked 5, 10 and 15 km/day respectively than would have been the case if they had been kept inactive in pens.

Some aspects of the energy and nitrogen metabolism of boars, gilts and barrows given diets containing different concentrations of protein

1980 ◽  
Vol 31 (3) ◽  
pp. 279-289 ◽  
Author(s):  
C. W. Holmes ◽  
J. R. Carr ◽  
G. Pearson
Keyword(s):  
Energy Intake ◽  
Crude Protein ◽  
Nitrogen Retention ◽  
Live Weight ◽  
Negative Influence ◽  
Metabolizable Energy ◽  
Energy Concentration ◽  
Nitrogen Intake ◽  
Energy Retention ◽  
Metabolizable Energy Intake

ABSTRACTFour diets which varied in crude protein concentration from 140 to 240 g crude protein per kg dry matter were given to gilts in experiment 1, and two diets containing 140 and 200 g crude protein per kg dry matter were given t o boars and barrows in experiment 2. Two levels of feeding were offered in both experiments and energy and nitrogen balances were measured at 30 and 90 kg live weight in both experiments, and also at 50 kg in experiment 1. Nitrogen intake had a small negative influence on energy retention by pigs of all sexes, an effect which was independent of the large positive effect of metabolizable energy intake. The ratio of metabolizable energy concentration to digestible energy concentration decreased in association with increases in crude protein concentration of the diets. The results show that comparisons of feeds on the basis of their digestible energy concentrations would lead to overestimation of the energy values of those containing high protein concentrations. Live weight (or age) and metabolizable energy intake exerted positive influences on the amount of energy retained per kg live-weight gain, whereas nitrogen intake exerted a negative influence. Values for energy retained per kg live-weight gain predicted from multiple regression equations, together with calculated values for maintenance and net efficiency, were used to predict the energy retention and growth rate of pigs in various circumstances.Nitrogen retention increased in association with increases in nitrogen intake for pigs of all sexes at 30 kg live weight; there was also a corresponding increase for boars at 90kg live weight, but not for gilts or barrows at this weight. Boars retained more nitrogen than did barrows at 30 and 90 kg live weight only if given the diet with the higher concentration of protein.Metabolizable energy intake appeared to exert a small positive influence on the nitrogen retention by pigs of all sexes at 90kg live weight; however, it appeared to have no influence on nitrogen retention by pigs at 30kg live weight.

The effect of dietary energy concentration on protein utilization during late pregnancy in ewes

1975 ◽  
Vol 85 (1) ◽  
pp. 175-184 ◽  
Author(s):  
J. A. Guada ◽  
J. J. Robinson ◽  
C. Fraser
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Nitrogen Retention ◽  
Late Pregnancy ◽  
Nitrogen Utilization ◽  
Metabolizable Energy ◽  
Late Gestation ◽  
Energy Concentration ◽  
Dietary Energy ◽  
Unit Increase

SUMMARYFrom 62 days of gestation to parturition, 20 Finnish Landrace x Dorset Horn ewes were each offered one of four diets with roughage to concentrate ratios of 20:80; 40:60; 60:40 and 80:20, at daily metabolizable energy and digestible crude protein intakes of 490 kJ and 3·55 g/kg W0·75respectively. Plasma concentration of free fatty acids, glucose and urea were determined weekly, and nitrogen balance and digestibility trials were carried out at 70–80 and 130–140 days of gestation.On all treatments the concentration of plasma free fatty acids increased during pregnancy from approximately 200–600 μ-equiv./l and the concentration of glucose and urea decreased by approximately 25%.Digestibility coefficients for dry matter and organic matter increased from 58 to 68% and from 60 to 70% respectively as the proportion of concentrates in the diet increased and were not affected by stage of gestation. The apparent digestibility of nitrogen was not affected by the energy concentration of the diet.Between mid and late gestation there was a mean increase in daily nitrogen retention of 2·5 g and an improvement in the efficiency of nitrogen utilization of 19 percentage units.Nitrogen retention and the efficiency with which the apparently digested nitrogen intake was retained increased as the dietary energy concentration was increased. The mean daily increases in nitrogen retention were 0·0135 and 0·0039 g for each percentage unit increase in the concentrate portion of the diet at mid and late gestation respectively. The corresponding values for the improvement in the efficiency of nitrogen utilization were 0·13 and 0·10%.

The effect of method of conservation of grass and supplementation on energy and nitrogen utilization by lambs

1999 ◽  
Vol 133 (4) ◽  
pp. 409-417
Author(s):  
D. E. KIRKPATRICK ◽  
R. W. J. STEEN
Keyword(s):  
Energy Intake ◽  
Heat Production ◽  
Dry Matter ◽  
Agricultural Research ◽  
Nitrogen Retention ◽  
Linear Increase ◽  
Nitrogen Utilization ◽  
Metabolizable Energy ◽  
Agricultural Research Council ◽  
Energy Retention

An experiment was carried out in 1994 to examine energy and nitrogen utilization of lambs offered two contrasting grass-based diets. The two forages, which were from the same parent herbage, were grass silage and grass which was conserved by freezing. They were offered as sole diets or supplemented with either 250 or 500 g concentrates per kg total dry matter intake (DMI) to give a total of six experimental treatments. Seventy-two Dutch Texel × Greyface (Border Leicester × Blackface) lambs, consisting of 36 males which were initially 36 (S.D. 4·9) kg liveweight and 36 females which were initially 34 (S.D. 2·5) kg liveweight were used. Ensiling significantly increased apparent digestibility of dry matter, energy and nitrogen (P<0·001), but had no significant effect on methane energy loss as a proportion of gross energy intake, metabolizable energy intake (MEI), heat production, energy retained, efficiency of utilization of energy for growth (kg) or nitrogen retention. Supplementation of forage with concentrates resulted in a curvilinear decrease in heat production expressed as a proportion of MEI (P<0·05) and a linear increase in energy retention, expressed as an absolute value or as a proportion of MEI (P<0·05). Supplementation of forage tended to increase kg when calculated using Agricultural Research Council estimates of maintenance energy requirements, but had no significant effect when alternative estimates of maintenance were used. It is concluded that ensiling had no effect on efficiency of utilization of energy or nitrogen as measured by indirect calorimetry.

A note on the response of British Friesian steers to trenbolone acetate and hexoestrol, and to alternation in dietary energy intake

1982 ◽  
Vol 35 (2) ◽  
pp. 277-280 ◽  
Author(s):  
H. Galbraith ◽  
K. J. Geraghty
Keyword(s):  
Growth Hormone ◽  
Energy Intake ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Dietary Energy ◽  
Plasma Urea ◽  
Trenbolone Acetate ◽  
Blood Constituents ◽  
Dietary Energy Intake ◽  
Main Effects

ABSTRACTFour steers from a group of eight British Friesian steers were implanted with 300 mg trenbolone acetate and 30 mg hexoestrol at the beginning of a 90-day trial period. The remainder were untreated. They were offered diets that varied in estimated content of metabolizable energy as follows (MJ/day): day 0 to 34 (period A), 100; day 35 to 60 (period B), 50; and day 61 to 90 (period C), 75 increasing to 110. Implanted steers gained significantly more live weight in periods A and C, and lost less in period B, than controls. Implanted steers had significantly elevated concentrations of plasma glucose in period A, and lower values for plasma urea and serum albumin throughout. Differences between control and implanted steers for the other blood constituents studied, including growth hormone, insulin and prolactin, were small and not significant. The main effects of changes in dietary energy intake on blood composition included significant increases in both groups of animals in the concentration of free fatty acids and growth hormone during underfeeding (period B). These concentrations decreased in period C, concomitant with significant increases in the concentrations of insulin and prolactin.

An assessment of whether energy was the first factor limiting production of dairy cows grazing kikuyu grass pasture

1979 ◽  
Vol 19 (100) ◽  
pp. 530 ◽  
Author(s):  
KW Moir ◽  
HG Dougherty ◽  
PJ Goodwin ◽  
FJ Humphreys ◽  
PR Martin
Keyword(s):  
Dairy Cows ◽  
Dry Matter ◽  
Body Weight Loss ◽  
Metabolizable Energy ◽  
Energy Concentration ◽  
Limiting Factor ◽  
Dietary Energy ◽  
Predominant Species ◽  
Kikuyu Grass ◽  
Whole Plants

Whole plants of kikuyu grass were taken at intervals over a 9-month period from four commercial dairy farms on which this grass was the predominant species. The plants were separated into leaf and stem fractions and their metabolizable energy (ME) concentrations were estimated from their cell-wall contents. The overall mean ME in the dry matter of leaf and stem on each farm was of the order of 11 and 9 MJ kg DM-1, respectively. From considerations of appetite limits depending upon whether energy was derived mainly from leaf or stem, and taking into account ME supplied from supplementary feeds, and ME requirements for milk production, it was concluded that the production of the herd with the highest mean production cow-1 (4140 kg lactation-1) was limited by dietary energy concentration, although the genetic capacity of the cows to produce milk at the expense of body weight loss overcame this limitation to some extent. On the other farms with low to intermediate levels of productivity, the amount of food on offer was the first limiting factor.

scholarly journals The effects of plane of nutrition and environmental temperature on the energy metabolism of the growing pig

1978 ◽  
Vol 40 (3) ◽  
pp. 433-438 ◽  
Author(s):  
W. H. Close
Keyword(s):  
Protein Turnover ◽  
Environmental Temperature ◽  
Growing Pigs ◽  
Metabolizable Energy ◽  
Energy Costs ◽  
Growing Pig ◽  
Wide Range ◽  
Energy Retention ◽  
Curvilinear Relation ◽  
Environmental Temperatures

1. From the relation between metabolizable energy (me) intake and heat loss (H), energy retention (ER), protein (P) and fat (F) deposition the energy costs of maintenance (MEm) and the partial efficiencies of energy retention (k) and protein (kp) and fat (kf) retention were determined in growing pigs at environmental temperatures of 10, 15, 20, 25 or 30°.2. k decreased with increase in environmental temperature from 0.79 at 10° to 0.63 at 30° with 0.67 at the thermally-neutral temperature of 25°. Each 0.04 decrease in k was associated with a 100 kJ/kg0.75 per d decrease in mem Analysis, within several ranges of environmental temperature, suggested a curvilinear relation between ER and me intake indicating a decrease in k with increase in level of feeding, particularly at thermally-neutral temperatures.3. Both kp and kf were similar at each environmental temperature and decreased from 0.78 at 10° to 0.63 at 30°. These values are discussed in relation to those predicted from experimentation and it is suggested that the wide range of predicted estimates of kp could be attributed to differences in the rate of protein turnover.

Review: Energy partitioning in broiler chickens

2008 ◽  
Vol 88 (2) ◽  
pp. 205-212 ◽  
Author(s):  
G. Lopez ◽  
S. Leeson
Keyword(s):  
Physical Activity ◽  
Heat Production ◽  
Broiler Chickens ◽  
The Body ◽  
Metabolizable Energy ◽  
Energy Concentration ◽  
Body Tissues ◽  
Energy Retention ◽  
Gross Energy ◽  
Concentration Changes

In commercial nutrition and in research studies, metabolizable energy (ME) is the standard measure of energy used in describing energy requirements and diets for poultry. The provision of dietary energy will influence the intake of all other nutrients. Broilers exhibit an outstanding ability to control their energy intake by adjusting their feed intake as diet energy concentration changes. There is still considerable debate on the accuracy, precision and usefulness of different procedures used for determining ME values of diets and ingredients. ME intake is generally partitioned into energy retained (ER) in body tissues (mainly as fat and protein) and as heat production (HP): ME = HP + ER. There are few reported estimates of HP and its components, fasting heat production (FHP), heat production due to physical activity and the thermic effect of feeding (TEF). Requirements for maintenance (MEm), including major components of FHP and physical activity, are established at around 155 kcal kg BW0.60. We recentlyreported that maintenance requirements for young broilers based on kg BW0.75 were 8% lower than the values estimated using kg BW0.60, and that BW raised to the exponent 0.60, was a more precise estimator. Gross energy retained in the body as fat (TERF) and protein (TERP), together contribute most of the total energy retained (TER) in the body. Efficiency of ME utilization above maintenance varies from 70 to 84% for lipid deposition in adult birds and between 37 and 85% in growing birds. Key words: Energy, broiler, metabolic rate, energy retention

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