scholarly journals Protein requirements of growing lambs

1973 ◽  
Vol 30 (1) ◽  
pp. 45-60 ◽  
Author(s):  
J. L. Black ◽  
G. R. Pearce ◽  
D. E. Tribe
Keyword(s):  
Energy Intake ◽  
Protein Intake ◽  
Milk Proteins ◽  
Live Weight ◽  
Metabolizable Energy ◽  
N Balance ◽  
Net Energy ◽  
Protein Requirements ◽  
Reference Protein ◽  
Group 2

1. The protein requirements of lambs were established by measuring nitrogen balance in seventy-four animals given liquid diets which passed direct to the abomasum. Four groups of lambs weighing approximately 8 kg (group 1), 13 kg (group 2), 21 kg (group 3) and 30 kg (group 4) received diets in which 0·10, 0·15, 0·20, 0·25, 0·30, 0·35 or 0·40 of the digestible energy was provided as protein (DPE:DE ratio) and a gross energy intake of from 1·30 to 1·42 MJ/kg0·73 per d.2. When the protein requirements were taken to correspond to the protein intake at the point of intersection of the line describing the increase in N balance with increase in protein intake and the line representing the maximum N balance, values of 0·25, 0·23, 0·17 and 0·12 DPE:DE ratio were obtained for groups 1–4 respectively. The requirements expressed in these terms can be applied only to lambs fed on liquid diets which contain milk proteins and escape fermentation in the rumen. To enable the results to be applied to lambs given other diets, the requirements were expressed as g reference-protein (defined as a theoretical protein with the ideal pattern of amino acids) per MJ net energy and were 11·6, 10·4, 8·0 and 6·2 for groups 1–4 respectively. The relationship between protein requirement (Y, g reference protein/MJ net energy) and live weight (X, kg) was: Y = 13·4–0·242X.3. The influence of energy intake on protein requirements in lambs is discussed and it is concluded that the results obtained are applicable to lambs given a metabolizable energy intake of more than about 1·75 times their maintenance requirement.4. Application of the estimated requirements to ruminant lambs and methods of formulating diets to supply the required quantity of reference protein/MJ net energy are discussed.

Effects of variations in energy and protein intake on digestibility, nitrogen balance and carcass composition in British Friesian castrate male cattle

1978 ◽  
Vol 26 (3) ◽  
pp. 233-243 ◽  
Author(s):  
T. W. Griffiths
Keyword(s):  
Protein Intake ◽  
Live Weight ◽  
Carcass Composition ◽  
Metabolizable Energy ◽  
N Balance ◽  
Favourable Effect ◽  
Castrate Male ◽  
Meat Content ◽  
Digestible Crude Protein ◽  
Total Fat

AbstractTwenty-seven castrate male cattle were used in two nutritional balance and slaughter experiments to measure the effects of increasing levels of dietary protein (9 to 15% in the dry matter) at two levels of feeding (approximately 16 and 22 MJ metabolizable energy (ME)/100 kg live weight (LW) per day) on digestibility, nitrogen (N) balance and carcass growth and composition over the LW range 130 to 390 kg.The higher level of feeding increased LW gain and carcass gain (CG) but higher protein intake increased LW gain and CG only at the higher feeding level as a result of its favourable effect on digestibility. N balance tended to overestimate carcass N retention at higher levels of protein intake.The higher level of feeding increased the separable fat and total fat in the carcass. Increased protein intake had no effect on the lean meat content but increased the percentage protein in the edible portion of the carcass. LW gain, CG and carcass energy deposition were related to ME intake only but N balance and carcass protein gain were related to both ME and digestible crude protein intake.

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

1994 ◽  
Vol 59 (1) ◽  
pp. 43-47 ◽  
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.

scholarly journals Effects of live weight and energy intake on nitrogen balance and total N requirements of lambs

1975 ◽  
Vol 33 (3) ◽  
pp. 399-413 ◽  
Author(s):  
J. L. Black ◽  
D. A. Griffiths
Keyword(s):  
Body Weight ◽  
Energy Intake ◽  
Nitrogen Balance ◽  
Live Weight ◽  
Metabolizable Energy ◽  
N Balance ◽  
Total N ◽  
Biological Value ◽  
Protein Energy ◽  
N Requirement

1. Results of 298 nitrogen balance studies from experiments with male cross-bred lambs, ranging in weight from 3 to 38 kg, which had been either fasted, or fed entirely on liquid diets of varying protein content at various energy intakes up to ad lib. intake, were used to quantitatively describe the effects of the amount and quality of absorbed protein, energy intake and live weight on N balance and total N requirement of lambs.2. When N intake was less than the amount required, N balance was independent of energy intake, but linearly related to absorbed N and metabolic body-weight (live weight0·75). In the fitted relationship, the coefficient of absorbed N was shown to be an estimate of the biological value of absorbed protein and the coefficient of metabolic body-weight was an estimate of the loss of endogenous N in both urine and faeces. For the milk-based diets used in the experiment biological value was 0·72 and the total endogenous N loss in urine and faeces was 148 mg N/kg0·75 per d.3. When N intake was in excess of the amount required, N balance in lambs of a constant live weight increased linearly with metabolizable energy (ME) intake, at a rate that decreased with increasing live weight. Similarly at constant ME intake, N balance was a curvilinear decreasing function of metabolic body-weight. When N balance was expressed per unit metabolic body-weight, it was constant for lambs of all weights when ME intake was about 0·23 MJ/kg0·75 per d, but it decreased linearly with increasing metabolic body-weight for ME intakes above this level.4. N balance of fasted lambs was several times less than predicted by either of the relationships established for fed animals, and was found to be linearly related to metabolic body-weight.5. The effects of energy intake and live weight on the total N requirement of lambs were determined. When total N requirement was expressed per unit of energy intake, it was found to be constant at 0·9 g N/MJ ME for all lambs irrespective of live weight when ME intake was 0·23 MJ/kg0·7 per d. However, as ME intake/unit metabolic body-weight was raised above this level, N requirement/unit ME intake increased for lambs weighing less than c. 23 kg, but decreased for heavier animals.

A comparative evaluation of functions for describing the relationship between live-weight gain and metabolizable energy intake in turkeys

2004 ◽  
Vol 142 (6) ◽  
pp. 691-695 ◽  
Author(s):  
H. DARMANI KUHI ◽  
E. KEBREAB ◽  
S. LOPEZ ◽  
J. FRANCE
Keyword(s):  
Energy Intake ◽  
Energy Requirement ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Net Energy ◽  
General Validity ◽  
Energy Needs ◽  
Functional Forms ◽  
Metabolizable Energy Intake ◽  
Predicted Values

The suitability of models specifically re-parameterized for analyzing energy balance data relating metabolizable energy intake to growth rate has recently been investigated in male broilers. In this study, the more adequate of those models was applied to growing turkeys to provide estimates of their energy needs for maintenance and growth. Three functional forms were used. They were: two equations representing diminishing returns behaviour (monomolecular and rectangular hyperbola); and one equation describing smooth sigmoidal behaviour with a fixed point of inflexion (Gompertz). The models estimated the metabolizable energy requirement for maintenance in turkeys to be 359–415 kJ/kg of live-weight/day. The predicted values of average net energy requirement for producing 1 g of gain in live-weight, between 1 and 4 times maintenance, varied from 8·7 to 10·9 kJ. These results and those previously reported for broilers are a basis for accepting the general validity of these models.

Experiments on the nutrition of the dairy heifer IV. Protein requirements of 2-year-old heifers

1963 ◽  
Vol 60 (3) ◽  
pp. 393-398 ◽  
Author(s):  
W. H. Broster ◽  
Valerie J. Tuck ◽  
C. C. Balch
Keyword(s):  
Weight Gain ◽  
Energy Intake ◽  
Protein Intake ◽  
Crude Protein ◽  
Live Weight ◽  
Mean Value ◽  
Live Weight Gain ◽  
Protein Requirements ◽  
Dietary Nitrogen ◽  
Digestible Crude Protein

1. In the winters of 1959–61 three randomized block experiments were carried out to study protein requirements of heifers of 800–1000 lb. live weight. 24 animals were used in each experiment. Half the animals were kept indoors; the remainder stayed out of doors except for 1 hr. per day when they came into covered yards to receive their concenrates ration.2. Rations were based on straw, cereals and roots. The intake of crude protein was varied by replacing cereals by decorticated ground nut meal. The estimated level of energy intake varied from 7·2–8·2 lb. starch equivalent/day between experiments, but the level was constant for all treatments within an experiment.3. At the end of each feeding trial the nitrogen balance was measured for 2 animals from each treatment. The results confirmed the estimated levels of digestible crude protein intakes upon which the experiments were based.4. An increase in intake of digestible crude protein (as determined in the metabolism trials) from 0·35 lb./day to 0·72 lb./day gave a marked response of 0·45 lb./day in the rate of live-weight gain. Further increases in protein intake gave little response in live-weight gain. It was concluded that for heifers of 800–900 lb. live weight the protein requirement for maintenance and a live-weight gain of 1·2 lb./day was 0·70 lb. digestible crude protein/day.5. Comparison of the estimated starch equivalent intakes in the three experiments showed that in heifers receiving 0·52 lb. digestible crude protein per day the rate of gain increased from 0·25 to 0·90 lb./day as the level of energy intake increased from 0·78 lb. starch equivalent/100 lb. live weight per day to 1·01 lb./100 lb. live weight.6. Biological value of the dietary nitrogen decreased as level of protein intake increased. The values for individual animals ranged from 61·3 to 82·4. The mean value was 69·5.7. The weather during these experiments was typical of winters in south-east England with mean minimum ground temperatures about 30° F. and mean maximum and minimum air temperatures of about 50° F. and 35° F., respectively. Snow fell occasionally only; 3½–5½ in. of rain fell in the period 1 January to 31 March. In 2 years out of 3 the outdoor group grew slightly faster than the indoor groups. In the third year this trend was reversed.

Effect of Diethylstilbestrol on Utilization of Energy by the Growing Chick

1958 ◽  
Vol 195 (3) ◽  
pp. 654-658 ◽  
Author(s):  
F. W. Hill ◽  
L. B. Carew ◽  
A. van Tienhoven
Keyword(s):  
Energy Consumption ◽  
Linear Function ◽  
Heat Production ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Yield ◽  
Net Energy ◽  
Lower Protein ◽  
Energy Gains ◽  
Total Tissue

Increased fat production in diethylstilbestrol-treated chicks was found to be due primarily to increased energy consumption and to a lesser extent to preferential synthesis of fat at the expense of protein tissue. This was shown in experiments comparing normal and estrogen-treated male chicks with respect to gains in live weight, fat and protein at two planes of nutrition, and the yield of metabolizable and productive (net) energy which they obtained from the diet. It was found that the fattening effect could not be due to increased digestibility, increased net energy yield from absorbed nutrients, or lowered heat production. Under the influence of estrogen, total tissue gain expressed in Calories was increased, and was composed of greater fat gain and lower protein gain. Tissue energy gains were a linear function of metabolizable energy consumption. This relationship predicted equal tissue energy gains under pair-feeding conditions, which was confirmed experimentally.

scholarly journals Relationships of retained energy and retained protein that influence the determination of cattle requirements of energy and protein using the California Net Energy System

2018 ◽  
Vol 3 (3) ◽  
pp. 1029-1039 ◽  
Author(s):  
Luis O Tedeschi
Keyword(s):  
Body Fat ◽  
Energy System ◽  
The Body ◽  
Metabolizable Energy ◽  
Net Energy ◽  
Body Protein ◽  
Protein Requirements ◽  
Growing Cattle ◽  
Lower Correlation

Abstract Interrelationships between retained energy (RE) and retained protein (RP) that are essential in determining the efficiency of use of feeds and the assessment of energy and protein requirements of growing cattle were analyzed. Two concerns were identified. The first concern was the conundrum of a satisfactory correlation between observed and predicted RE (r = 0.93) or between observed and predicted RP when using predicted RE to estimate RP (r = 0.939), but a much lower correlation between observed and predicted RP when using observed RE to estimate RP (r = 0.679). The higher correlation when using predicted vs. observed RE is a concern because it indicates an interdependency between predicted RP and predicted RE that is needed to predict RP with a higher precision. These internal offsetting errors create an apparent overall adequacy of nutrition modeling that is elusive, thus potentially destabilizing the predictability of nutrition models when submodels are changed independently. In part, the unsatisfactory prediction of RP from observed RE might be related to the fact that body fat has a caloric value that is 1.65 times greater than body protein and the body deposition of fat increases exponentially as an animal matures, whereas body deposition of protein tends to plateau. Thus, body fat is more influential than body protein in determining RE, and inaccuracies in measuring body protein will be reflected in the RP comparison but suppressed in the RE calculation. The second concern is related to the disconnection when predicting partial efficiency of use of metabolizable energy for growth (kG) using the proportion of RE deposited as protein—carcass approach—vs. using the concentration of metabolizable energy of the diet—diet approach. The culprit of this disconnection might be related to how energy losses that are associated with supporting energy-expending processes (HiEv) are allocated between these approaches. When computing kG, the diet approach likely assigns the HiEv to the RE pool, whereas the carcass approach ignores the HiEV, assigning it to the overall heat production that is used to support the tissue metabolism. Opportunities exist for improving the California Net Energy System regarding the relationships of RE and RP in computing the requirements for energy and protein by growing cattle, but procedural changes might be needed such as increased accuracy in the determination of body composition and better partitioning of energy.

Threshold of Daily Energy and Protein Requirements to Prevent Weight Loss in Patients with Alzheimer’s Disease in Japan

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Nakamura T ◽  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Weight Loss ◽  
Energy Intake ◽  
Protein Intake ◽  
Care Hospital ◽  
Point Energy ◽  
Protein Requirements ◽  
Food Records ◽  
Daily Energy

Background and Aims: Patients with Alzheimer’s Disease (AD) frequently develop weight loss. However, little is known about the energy and protein thresholds that cause weight loss. The purpose of this study was to determine the threshold of daily energy and protein requirements to prevent weight loss in patients with AD. Methods: We included 75 Japanese long-term care hospital patients with probable AD (22 men and 53 women, aged 65–101 years) in an interventional study. After a one-week survey using weighed food records weighed food records, the relationship between the obtained energy and protein intake and weight loss after three months was examined. Multiple regression analysis was used to examine the daily determinants of weight loss. Subsequently, receiver operating characteristic curves were used to examine the threshold for discriminating weight loss. Results: Sixty-one (81.3%) patients were malnourished or at risk of malnutrition. Twenty patients (26.7%) had >5% weight loss. The significant associations with weight loss were Mini Nutritional Assessment (MNA) point, energy intake, and protein intake; with a MNA point at cutoff of 17.25, an energy intake at cutoff of 29.93kcal/kg, and a protein intake at cutoff of 1.122g/kg. Conclusion: To prevent weight loss in AD patients, it is important to prevent malnutrition and administer more than 30kcal/kg energy intake and more than 1.1g/kg protein intake. Future studies with a larger sample size are needed to determine the threshold of daily energy and protein requirements to prevent weight loss.

Effect of feeding level and dietary protein content on the growth, body composition and rate of protein deposition in pigs growing from 45 to 90 kg

1984 ◽  
Vol 38 (2) ◽  
pp. 233-240 ◽  
Author(s):  
R. G. Campbell ◽  
M. R. Taverner ◽  
D. M. Curic
Keyword(s):  
Energy Intake ◽  
Body Fat ◽  
Protein Intake ◽  
Crude Protein ◽  
Energy Content ◽  
Live Weight ◽  
Feeding Level ◽  
Protein Deposition ◽  
Dietary Crude Protein ◽  
Protein Diets

ABSTRACT1. Eight diets of similar energy content, ranging in crude protein concentration from 95 to 256 g/kg, were given at either 2·5 or 3·2 times the energy level for maintenance to entire male pigs growing from 45 to 90 kg live weight.2. Growth rate improved with increase in feeding level and with increasing dietary crude protein up to 164 g/kg (P < 0·05). The food conversion ratio improved with each increase in dietary CP up to 186 and 164 g/kg on the lower and higher feeding treatments, respectively (P < 0·05). It was also improved with increase in level of feeding of the lower-protein diets but deteriorated with increase in level of intake of the higher-protein diets (P < 005).3. Rate of protein deposition improved with increasing dietary crude protein up to 186 and 164 g/kg on the lower and higher feeding treatments, respectively (P < 005). The results showed that, for pigs given diets deficient in crude protein, rate of protein deposition was linearly related to protein intake (P < 0·001) but independent of energy intake. For pigs given a diet adequate in crude protein, rate of protein deposition was related to energy intake and independent of crude protein intake.4. Body fat content at 90 kg decreased with increasing dietary crude protein up to 210 and 164 g/kg on the lower and higher feeding treatments, respectively (P < 0·05), and was increased by raising the level of intake of the higher-crude protein diets (P < 0·05). However, the influence of feeding level on body fat diminished as dietary crude protein was reduced.

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.

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