A note on energy requirements for maintenance of lean and fat Angus, Hereford and Simmental cows

1984 ◽  
Vol 39 (2) ◽  
pp. 305-309 ◽  
Author(s):  
C. L. Ferrell ◽  
T. G. Jenkins

ABSTRACTMature Angus (A), Hereford (H) and Simmental (S) cows (16 each) that had been randomly assigned and fed a maize silage-based diet at different levels of intake during lactation were selected.Lean and fat A, H and S cows were fed the maize silage-based diet individually to provide metabolizable energy (ME) intakes of 542, 506; 476, 437; and 624, 597 kj/kg0.75 per day respectively for 84 days. Daily weight gains of lean cows were greater than those of fat cows (0·40 v. 0·11 kg/day) even though daily ME intakes were less (55·2 v. 62·4 MJ/day). Theoretical estimates of ME requirements for maintenance were less for lean than for fat cows, and maintenance of A and H cows tended to be less than those of S cows.These results suggest that cow maintenance requirements increased in association with fatness that resulted from the previously imposed nutritional regimes and tended to differ among cow breeds.

1996 ◽  
Vol 63 (3) ◽  
pp. 549-561 ◽  
Author(s):  
P. W. Knap

AbstractA dynamic model for simulation of growth in pigs, that was extended by a module to describe protein turn-over, was made stochastic in order to simulate groups of pigs with among-animal variation in the maximum daily protein deposition (Pdep, maxK in the minimum lipid to protein deposition rate (Ri/pimin), and in the distributionof body protein over protein pools (muscle, connective tissue, and other proteins). As a result, these simulated pigs show among-animal variation in body protein content and composition. This in turn leads to among-animal variation in energy requirements for protein turn-over and this causes among-animal variation in maintenance metabolizable energy requirements (MEmaint)as a result of variation in body composition.Simulated population means for PieVimax were varied in seven steps from 100 to 250 g/day, with an among-animal variation coefficient of 0·10; the feeding level was also varied in seven steps. Dependent on the levels of these input variables, 100-kg pigs showed within-population standard deviations in body protein and lipid content of 0·31 to 0·54 kg and 1·22 to 2·17 kg, respectively. ME showed a protein-turn-over-related, within-population coefficient of variation of 0·014 to 0·02. Comparisons over populations suggests that a 1·50 proportional increase in Pdep, max (from 100 to 250 g/day) would increase protein-turn-over-related MEmaint by 11 to 15%, from between 470 and 486 to 541 k] ME per kg body weight0'75 per day. The inferences that can be made from this with regard to experimental design are discussed.


1994 ◽  
Vol 74 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Z. Jiang ◽  
R. J. Hudson

Seasonal energy intakes of 6- to 14-mo-old wapiti hinds were determined in energy balance trials under pen and field conditions in winter, spring and summer. Six animals grazed native pastures supplemented with alfalfa hay when pasture availability declined in winter. Another six were penned and fed alfalfa-barley pellets to maximize growth throughout the year. Season and diet-specific metabolizable energy requirements for maintenance and liveweight gain were determined from regression of metabolizable energy intake on gain. Daily maintenance requirements of penned wapiti ranged from (mean ± SE) 473 ± 35 kJ kg−0.75 in winter to 728 ± 78 kJ kg−0.75 in summer. On spring and summer pasture, daily ecological maintenance requirements ranged from 900 ± 26 to 984 ± 37 kJ kg−0.75. Energy requirements for gain were the same in pen and field trials, ranging from 25 ± 6 to 33 ± 5 kJ g−1 in winter and from 40 ± 6 to 43 ± 12 kJ g−1 in spring and summer. This study provides basic information on the metabolizable energy needs of wapiti and insights into how their seasonal requirements can be optimally met. Key words: Elk, metabolizable energy requirement, growth, physiological maintenance, ecological maintenance, seasonality, energy balance


1975 ◽  
Vol 33 (2) ◽  
pp. 127-139 ◽  
Author(s):  
B. R. Patle ◽  
V. D. Mudgal

1. Twenty-seven energy and protein balances were done using nine cross-bred (Brown Swiss × Sahiwal) mature bullocks in a series of three balance trials. The bullocks were fed 75, 100 and 125 % of the metabolizable energy (ME) and digestible crude protein standard values recommended by the (US) National Research Council (1966). Heat production was estimated by indirect calorimetry, by collection and analysis of respiratory gases2. Utilization of energy for maintenance and fat production was estimated by computing regression of energy balance v. digestible energy (DE) and ME separately on a metabolic body size (kg body-weight (W)0·75) basis. Maintenance energy requirements and efficiency of utilization of ME for lipogenesis were estimated using multiple regression of ME intake, also. Heat production (and thus energy balance) was corrected for excess nitrogen intake3. An attempt was made to measure basal heat production of bullocks so that the net energy requirements for maintenance could be estimated. Extrapolation of the regression line of energy balance v. ME intake below maintenance on a W0·75 basis gave a basal metabolism of 348·09 kJ/W0·75 per d4. Energy requirements for maintenance were (kJ/kg W0·75 per d): 539·43 DE, 448·81 ME and 348·09 net energy. The results of multiple regression gave a requirement of 432·15 kJ ME/kg W0·75 per d for maintenance5. The efficiency of utilization of ME for maintenance was 81·34% while for lipogenesis it was 54·5 %.


1974 ◽  
Vol 19 (1) ◽  
pp. 1-12 ◽  
Author(s):  
C. W. Holmes ◽  
N. R. McLean

SUMMARY1. The heat production of four sows, approximately 17 months old at the start of the experiment, was measured at five ambient temperatures from 23° to 6°C. Food intake was controlled at different levels for different sows; one sow conceived during the experiment.2. Heat production increased consistently as temperature decreased from 23° to 6°C; the relative effect on heat production of exposure to low temperatures was greater the lower the level of feeding.3. Estimated values for whole body conductance decreased as ambient temperature decreased to minimum values of 73 to 77 kcal/m2. day. °C for three sows and 87 kcal/m2. day.°C for the fourth sow, which had a considerably thinner backfat than the others.4. Estimated values for lower critical temperature varied from 10° to 20°C, with the lower values associated generally with the higher levels of feeding; nevertheless heat production was consistently lower at 23°C than at 18°C.5. Differences in level of feeding were generally associated with differences in live weight, and it was difficult to obtain reliable estimates of metabolizable energy requirements for maintenance and of net efficiency of utilization of metabolizable energy above maintenance; however analysis on the basis of live weight0·75 produced values of 92 kcal/kg0·75 per day at 23°C and 106 kcal/kg0·75 per day at 18°C for maintenance and between 67 and 75% for the efficiency of utilization above maintenance.


1979 ◽  
Vol 29 (3) ◽  
pp. 339-355 ◽  
Author(s):  
Pamela A Geisler ◽  
C. Merryl Jones

ABSTRACTA computer program is described which allows the calculation throughout pregnancy of the energy requirements of a ewe of any weight carrying any number of foetuses. The calculations rely on a prediction of potential lamb birth weight, from which a foetal growth curve of weight against time from conception is generated. Tied to the foetal growth curve are the growths of the placenta and fluids, while growth of the uterus is related to the ewe's weight at mating. Weights are converted to energy through energy density curves applicable through pregnancy for each component. An efficiency factor converts this energy requirement into a metabolizable energy requirement. With assumptions on the maintenance requirements for the ewe-foetus system, the total requirement for energy during pregnancy is calculated.Predictions from the model are compared with other estimates of energy requirements available in the literature. The sensitivity of the predictions of energy requirements for the pregnant ewe to variations in the assumptions made in the construction of the model is discussed. The most important assumptions are those on the maintenance requirements for the ewe-foetus system. Effects on the predicted energy requirements of varying either the efficiency for foetal growth or the gestation length are also discussed.


1990 ◽  
Vol 63 (2) ◽  
pp. 155-163 ◽  
Author(s):  
C. Prieto ◽  
J. F. Aguilera ◽  
L. Lara ◽  
J. FonollÁ

Sixteen adult castrated male goats of the Granadina breed, with initial live weights ranging from 26.0 to 33.3 kg were used in two experiments to determine their protein and energy requirements for maintenance. Digestibility, nitrogen and energy balance measurements were made during the experiments. Two diets, which were based on pelleted lucerne (Medicago sativa) hay alone or on this forage and barley, were individually given at about maintenance level once daily. Gas exchange was measured using open-circuit respiration chambers. Fasting heat production was also determined. By regression analysis endogenous urinary N and maintenance requirements for N were estimated to be 119 mg/kg body-weight (W)0.75 per d and 409 mg total N/kg W0.75 per d respectively. Fasting heat production was 324 kJ/kg W0.75. The energy requirement for maintenance was calculated by regression of energy balance on metabolizable energy (ME) intake and a value of 443 kJ/kg W0.75 per d was found. The overall efficiency of utilization of ME for maintenance was 0.73.


1972 ◽  
Vol 14 (1) ◽  
pp. 17-23 ◽  
Author(s):  
C. A. Zulberti ◽  
J. T. Reid

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.


1982 ◽  
Vol 48 (3) ◽  
pp. 527-541 ◽  
Author(s):  
B. R. Cottrill ◽  
D. E. Beever ◽  
A. R. Austin ◽  
D. F. Osbourn

1. A total of six diets based on maize silage were formulated to examine the effect of protein- and non-protein-nitrogen, and energy supplementation on the flow of amino acids to the small intestine and the synthesis of microbial amino acids in the rumen of growing cattle. All diets contained 24 g totai nitrogen (N)/kg dry matter (DM), of which 550 g N/kg total N was supplied by either urea or fish meal. Four diets contained low levels of barley (estimated total dietary metabolizable energy content of 10·4 M J/kgDM) and urea-N and fish meal-N were supplied in the ratios 3:1, 1·4:1, 0·6:1 and 0·3:1. The other two diets contained between 300 and 400 g barley/kg total diet (11·3 MJ metabolizable energy/kg DM) and the urea-N to fish meal-N ratios were 3:1 and 0·3:1.2. On the four low-energy diets, fish meal inclusion tended to reduce the extent of organic matter (OM) digestion in the rumen but significantly increased duodenal amino acid supply (P< 0·05) in a quadratic manner. Microbial-N synthesis was increased by the two intermediate levels of fish meal supplementation but declined at the highest level of inclusion. With increasing levels of fish meal inclusion, a greater proportion of the dietary protein was found to escape rumen degradation and the apparent degradabilities of fish meal and maize-silage protein of all four diets were estimated to be 0·22 and 0·73 respectively.3. The substitution of barley for part of the maize silage enhanced duodenal supply of amino acids, irrespective of the form of the N supplement, and stimulated microbial amino acid synthesis. For all diets efficiency of microbial-N synthesis was found to vary between 22·5 and 46 g N/kg rumen-digested OM. Contrary to what was found for low-energy diets, the inclusion of fish meal tended to reduce the flow of dietary protein to the small intestine, but these differences were not statistically significant.4. The results appertaining to microbial synthesis, dietary protein degradabilities and duodenal amino acid flow for all diets are discussed in relation to the Agricultural Research Council (1980) proposals for the protein requirements of ruminants, and the production responses observed when similar diets were fed to growing cattle.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 84-85
Author(s):  
Luis O Tedeschi

Abstract The understanding of how nutrition influences the body composition of growing animals has fascinated researchers for centuries. It involves the expertise of scientists with different areas of knowledge, encompassing the composition of the diet and its nutritive value to the fermentation and digestion of substrates to the absorption and metabolism of nutrients, and finally, to the deposition of fat, protein, and minerals in body tissues. The comparative slaughter technique is the preferred method to assess the body composition of growing and finishing animals. However, the methodological procedures are labor-intensive, expensive, and time-consuming, facilitating the incidence of errors and inconsistencies of the measurements that are collected, including the initial animal’s body composition. First, retained fat and protein (RP) are used to compute retained energy (RE). Then, RP and RE are used to compute protein and energy requirements for growth. Heat production, calculated from the metabolizable energy (ME) intake for animals at maintenance, is used to compute maintenance requirements. Three areas of concern exist for this approach: 1) the efficiencies of possible mobilization of fat and protein tissues during the feeding period are unaccounted for, especially for the animals fed near the maintenance level of intake; 2) the correlation between observed and predicted RP when using predicted RE is higher than when using observed RE (0.939 vs. 0.679); and 3) the disconnection when predicting partial efficiency of use of ME for growth using the proportion of RE deposited as protein — carcass approach — versus using the concentration of ME of the diet — diet approach. These concerns raised questions about the interdependency between predicted RP and RE and the existence of internal offsetting errors that may prevent overall adequacy in predicting energy and protein requirements of beef cattle.


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