scholarly journals The effect of dietary protein and energy restriction on heat production and growth costs in the young rat

1987 ◽  
Vol 58 (1) ◽  
pp. 73-85 ◽  
Author(s):  
Penny A. Coyer ◽  
J. P. W. Rivers ◽  
D. J. Millward

1. The effect of dietary protein and energy restriction on heat production and growth costs has been examined in rats fed on a marginal (MP) or high (HP) protein diet, containing 9.2 % or 22 % respectively of the gross energy content as casein. Diets were given either ad fib. or at approximately 25, 50 or 75 % of the ad lib. intake.2. Heat production (kJ/kg body-weight (W)0.75 per d) was increased by 23% in rats fed on the MP diet ad Lib., as compared with their HP controls (P < 0.01).3. Factorial analysis of the data showed that the overall cost of energy deposition (kJ/kJ; Ee) was elevated on the MP diet (MP 1.7, HP 1.28; P < 0.001). Maintenance requirements (kJ/kg W0.75 per d) for zero energy balance were unchanged (MP 562, HP 573).The partial energy cost of protein deposition (Ep) varied with dietary manipulation. If the partial energy cost of fat deposition (Ef) was assumed constant at 1.25 kJ/kJ, and maintenance requirements were assumed to vary with metabolic body size (W0.75), Ep was elevated on the MP diet. On both diets, Ep was reduced at low energy intakes.5. The significance of these results is discussed in the context of current approaches to the analysis and interpretation of findings describing dietary induced changes in the rate of heat production.

1979 ◽  
Vol 6 (3) ◽  
pp. 337 ◽  
Author(s):  
CE Cannon

Captive Trichoglossus haematodus were given a restricted diet of bread and honey or a supplemented diet of bread, honey and the fortified milk powder 'Complan'. On the former diet they lost weight and were less active compared to those on the latter. Both diets were very fluid and birds consumed the equivalent of 38 to 47% of their bodyweight daily. However, they ate significantly more of the supplemented diet, 15.1 g DM daily, than of the bread and honey diet, 12.8 g daily. Birds given the supplemented diet voided more excreta and lost more excretory energy, 28.9 kJ/day, than the others, 17.9 kJ/day, but the 2 groups did not differ in their gross energy intake or maintenance requirements. A captive lorikeet weighing about 150 g required about 230 kJ/day for existence, with an efficiency of food use of 89%. Allowing a higher energy cost for free existence, it is suggested that wild lorikeets could gather sufficient energy daily in 2.5 h.


2021 ◽  
Vol 34 (1) ◽  
pp. 109-118
Author(s):  
Zhongchao Li ◽  
Zhiqian Lyu ◽  
Hu Liu ◽  
Dewen Liu ◽  
Neil Jaworski ◽  
...  

Objective: The objective of this study was to determine net energy (NE) of expeller-press (EP-RSM) and solvent-extracted rapeseed meal (SE-RSM) and to establish equations for predicting the NE in rapeseed meal (RSM) fed to growing pigs.Methods: Thirty-six barrows (initial body weight [BW], 41.1±2.2 kg) were allotted into 6 diets comprising a corn-soybean meal basal diet and 5 diets containing 19.50% RSM added at the expense of corn and soybean meal. The experiment had 6 periods and 6 replicate pigs per diet. During each period, the pigs were individually housed in metabolism crates for 16 days which included 7 days for adaption to diets. On day 8, pigs were transferred to respiration chambers and fed their respective diet at 2,000 kJ metabolizable energy (ME)/kg BW<sup>0.6</sup>/d. Feces and urine were collected, and daily heat production was measured from day 9 to 13. On days 14 and 15, the pigs were fed at 890 kJ ME/kg BW<sup>0.6</sup>/d and fasted on day 16 for evaluation of fasting heat production (FHP).Results: The FHP of pigs averaged 790 kJ/kg BW<sup>0.6</sup>/d and was not affected by the diet composition. The NE values were 10.80 and 8.45 MJ/kg DM for EP-RSM and SE-RSM, respectively. The NE value was positively correlated with gross energy (GE), digestible energy (DE), ME, and ether extract (EE). The best fit equation for NE of RSM was NE (MJ/kg DM) = 1.14×DE (MJ/kg DM)+0.46×crude protein (% of DM)–25.24 (n = 8, R<sup>2</sup> = 0.96, p<0.01). The equation NE (MJ/kg DM) = 0.22×EE (% of DM)–0.79×ash (% of DM)+14.36 (n = 8, R<sup>2</sup> = 0.77, p = 0.018) may be utilized to quickly determine the NE in RSM when DE or ME values are unavailable.Conclusion: The NE values of EP-RSM and SE-RSM were 10.80 and 8.45 MJ/kg DM. The NE value of RSM can be well predicted based on energy content (GE, DE, and ME) and proximate analysis.


1990 ◽  
Vol 51 (2) ◽  
pp. 389-397 ◽  
Author(s):  
D. S. Rao ◽  
K. J. McCracken

ABSTRACTThe effects of dietary protein (151 to 282 g crude protein per kg dry matter (DM)) and lysine (8·5 to 16·4 g/kg DM) on the carcass composition and energy metabolism of entire male pigs, given food close to appetite, was studied from 33 to 88 kg. Four replicates (three Landrace and one Duroc) of four littermates were used. Energy and nitrogen (N) balances were conducted at approximately 35 to 43, 58 to 65 and 78 to 85 kg and body composition was determined at slaughter. There was no effect of dietary treatment on the crude protein content of the empty body (EBW) but the DM (P < 0·001), fat (P < 0·001) and ash (P < 0·05) proportions and fat: protein ratio in EBW (P < 0·01) increased with decreasing dietary protein level. The mean maximum protein retention was 183 g/day. Retention of protein (P < 0·05) and proportion of protein energy in the gain (P < 0·01) decreased linearly and fat retention (P < 0·001) and energy content of the gain (P < 001) increased with decreasing dietary protein. The N retention values calculated from balance data were proportionately 0·21 higher at high protein intakes (509 g/day) and 0·056 higher at low protein intakes (329 g/day) than the values obtained by slaughter. Using the ideal protein system the value for the efficiency of utilization of apparently digested ideal protein for protein deposition (a2) fell linearly (P < 0·001), based on the slaughter data, as dietary protein content increased. Heat production, calculated from slaughter data, was proportionately 0·07 higher than that measured by indirect calorimetry and 0·17 higher than the computed value for heat production using the standard values of energy costs for maintenance and for protein and fat deposition.


1972 ◽  
Vol 23 (3) ◽  
pp. 499 ◽  
Author(s):  
DJ Farrell ◽  
RA Leng ◽  
JL Corbett

The fasting heat production (kilocalories per kilogram liveweight) of sheep normally kept at pasture decreased during a period of 4 months when their liveweight was declining owing to low availability of pasture herbage, but increased considerably after shearing in autumn. It subsequently remained higher than for well-nourished sheep, which showed an effect of loss of fleece for only a few weeks. In thin animals critical temperature was higher after shearing, and their rate of increase in heat production as ambient temperature fell below critical was greater than in sheep in good body condition. Energy expenditure per unit of horizontal locomotion or vertical ascent (calories per metre per kilogram) did not vary significantly with body condition, but total daily expenditure at pasture was probably greater for the undernourished sheep. These results, and energy expenditures at pasture calculated from estimates of carbon dioxide entry rate, were consistent with observations on ruminal concentrations of volatile fatty acids and body energy content. The observations indicated that maintenance requirements (kilocalories per kilogram liveweight) of undernourished grazing sheep might be up to 45% greater than those of well-nourished sheep, particularly during inclement weather. __________________ *Part I, Aust. J. Agric. Res., 23: 483 (1972).


1976 ◽  
Vol 56 (3) ◽  
pp. 451-456 ◽  
Author(s):  
M. IVAN ◽  
J. P. BOWLAND

Four castrated pigs, each fitted with a re-entrant cannula in the terminal ileum, were used to study digestion in the small intestine. A nitrogen-free diet was used for the estimation of metabolic nitrogen and amino acids. Faba beans, as the sole source of dietary protein, were used raw or after autoclaving for 30 or 60 min. The four diets were fed to the pigs in a 4 × 4 latin square experiment. The pigs were fed each diet for 6 days prior to a 24-hr collection of total ileal contents. Autoclaving of faba beans had no significant effect on digestibility of dry matter, gross energy, nitrogen and individual amino acids except arginine, which was significantly increased. The intestinal uptake of arginine was the highest and of cystine the lowest in all faba bean diets. It was concluded that autoclaving faba beans had no beneficial effect on the digestion of nutrients in the small intestine of the pig.


1981 ◽  
Vol 240 (6) ◽  
pp. E712-E721 ◽  
Author(s):  
K. J. Motil ◽  
D. E. Matthews ◽  
D. M. Bier ◽  
J. F. Burke ◽  
H. N. Munro ◽  
...  

Whole-body leucine and lysine metabolism was explored in young adult men by a primed constant intravenous infusion of a mixture of L-[1–13C]leucine and L-[alpha-15N]lysine over a 4-h period. Subjects were studied after an overnight fast (postabsorptive state) or while consuming hourly meals (fed state) after adaptation to diets providing either a surfeit level of protein (1.5 g.kg body-1.day-1), a level approximating maintenance requirements (marginal intake) (0.6 g.kg body wt-1.day-1), or a grossly inadequate level (0.1 g.kg-1.day-1). The change in protein intake from a marginal to a surfeit level was associated with an increased leucine flux and incorporation of leucine into body protein. In the fed state, oxidation of leucine increased sharply and release of leucine from tissue protein diminished. When dietary protein intake was reduced from the requirement to inadequate level, leucine flux and body protein synthesis and protein breakdown were reduced, together with a smaller reduction in leucine oxidation. The response of the metabolism of [15N]lysine was responsible for maintenance of leucine and other essential amino acid economy, and they appear to be related to the nitrogen and amino acid requirements of the subject. These findings also demonstrate an effect of meals, modulated by their protein content, on the dynamics of whole-body amino acid metabolism.


1963 ◽  
Vol 5 (1) ◽  
pp. 11-16 ◽  
Author(s):  
J. P. Langlands ◽  
J. L. Corbett ◽  
I. McDonald ◽  
G. W. Reid

SUMMARYThe mean daily digestible organic matter intake (D) of each of 47 adult sheep during a grazing period of mean length 48 days was estimated by the chromium sesquioxide/faecal nitrogen technique. Mean live-weights (W) and mean daily weight gains (G) were also measured.The regression of D on W and G, and the underlying or functional relationship between D, W and G were both estimated. From the underlying relationship, the preferred equation, the maintenance requirement of a 100 lb. sheep at pasture is estimated to be 1·02 lb. digestible organic matter daily. This value is 24% higher than the corresponding value for housed sheep obtained previously by us.This result is compared with other estimates of the energy cost of grazing and it is concluded that further work is needed in order to define those circumstances which elevate the maintenance requirements of grazing animals.


1977 ◽  
Vol 37 (3) ◽  
pp. 355-363 ◽  
Author(s):  
J. D. Pullar ◽  
A. J. F. Webster

1. Measurements were made of energy balance by direct calorimetry, and of nitrogen balance in groups of lean and congenitally obese (‘fatty’) Zucker rats at body-weights of 200 and 350 g given a highly digestible semisynthetic diet at 14.0 or 18.4 g/rat per 24 h.2. Losses of food energy and N in faeces were very small. The fatty rats lost much more N in urine than did lean rats. Despite this the proportion of gross energy that was metabolized was 0.92 for both fatty and lean rats.3. In all trials, fatty rats lost a smaller proportion of metabolizable energy (ME) as heat and deposited less as protein than thin rats but deposited much more as fat.4. The amounts of ME required to deposit 1 kJ of protein and 1 kJ of fat respectively were shown by regression analysis to be 2.25 (±0.16) and 1.36 (±0.06) kJ respectively. These values agree extremely closely with recent, more tentative, estimates based on assumptions as to maintenance requirement which the present experiments were able to circumvent. It may be concluded with confidence that the energy costs of depositing 1 g of protein or fat are almost identical at 53 kJ ME/g.


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