Seasonal changes of metabolism and appetite in Soay rams

1999 ◽  
Vol 69 (1) ◽  
pp. 191-202 ◽  
Author(s):  
C. McG. Argot ◽  
J. S. Smith ◽  
R. N. B. Kay
Keyword(s):  
Seasonal Changes ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Maintenance Energy ◽  
Dietary Energy ◽  
Energy Retention ◽  
Photoperiodic Regime ◽  
Ad Libitum ◽  
Metabolizable Energy Intake

AbstractRelationships between photoperiod and cycles of voluntary food intake (VFI) and maintenance energy requirements (MER) were determined in Soay rams, subjected to a 6-month photoperiodic regime. Food was offered ad libitum (no. = 5) or at a predicted maintenance level (no. = 5). All rams demonstrated 6-month cycles of VFI, growth and reproductive status. Metabolizable energy intake (MEI) was greatest in rams given food ad libitum (666 (s.e. 21.7) kJ/kg metabolic live weight (M0·75) and food-restricted (528 (s.e. 12.2) kJ/kg M0·75) rams during sexual quiescence. Conversely, MEI was minimal (ad libitum, 289 (s.e. 8.4) kJ/kg M0·75; restricted, 428 (s.e. 8.1) kJ/kg M0·75) during the rut. Distinct cycles of heat production (HP) accompanied changes in MEL Changes in HP were similar (P > 0·05) for both groups (ad libitum, 520 (s.e. 22.1) to 394 (s.e. 9.2) kJ/kg M0·75; restricted 503 (s.e. 14.0) to 407 (s.e. 17.5) kJ/kg M0·75) and therefore energy retention varied more (P < 0·015) when rams were given food ad libitum (ad libitum, 131 (s.e. 43-1) to -106 (s.e. 38.2) kJ/kg M0·75; restricted, 78·0 (s.e. 27.1) to -53.0 (s.e. 38.2) kJ/ kg M0·75). Apparent digestibility of dietary energy varied inversely with MEI (P < 0·01). MERs ranged from 524 (s.e. 35.0) kJ/kg M0·75 to 401 (s.e. 27.3) kJ/kg M0·75, a proportional fluctuation of ±0·13. Changes in metabolic rate preceded those in appetite, suggesting a causal relationship.

scholarly journals Estimates of maintenance requirement of growing lambs

1979 ◽  
Vol 41 (1) ◽  
pp. 223-229 ◽  
Author(s):  
D. J. Thomson ◽  
J. S. Fenlon ◽  
S. B. Cammell
Keyword(s):  
Live Weight ◽  
Metabolizable Energy ◽  
Alternative Analysis ◽  
Maintenance Requirement ◽  
Common Value ◽  
Residual Variation ◽  
Energy Retention ◽  
Metabolizable Energy Intake ◽  
Total Body ◽  
Body Energy

1. Total body energy retention (ER) and metabolizable energy intake (MEI) values from experiments with 231 lambs (Suffolk ♂× (Border Leicester ♂× Cheviot ♀) ♀) housed indoors and given thirteen forage diets were used to estimate the metabolizable energy (ME) required for maintenance.2. ER was measured using the comparative slaughter technique, and the lambs were fed at several planes of nutrition above maintenance between 2 and 5 months of age.3. The daily ER and MEI results were scaled to live weight (kg0.75) and linear regression lines fitted to the values for individual diets. Extrapolation of the fitted lines to zero ER gave estimates of maintenance requirement ranging from 141 to 466 kJ ME/kg0.75 per d and values for the efficiency of utilization of ME for growth and fattening (kf) of 0.25–0.53 (mean 0.39).4. An alternative analysis constrained the estimated maintenance requirement to be the same for all diets. An iterative search procedure indicated minimal residual variation at 339 kJ/kg0.75 per d. This common value of ME for maintenance gave kf values ranging from 0.30 to 0.54 (mean 0.39).5. The implications of the technique were considered togethe with some discussion of the variability of the estimate. Allowing the minimum RSD to vary by 10% gave a maintenance requirement of between 231 and 408 kJ/kg0.75 per d.

Net utilization of roughage and concentrate diets by sheep

1976 ◽  
Vol 35 (2) ◽  
pp. 201-209 ◽  
Author(s):  
P. I. Wilke ◽  
F. J. Van Der Merwe
Keyword(s):  
South African ◽  
Energy Requirement ◽  
Experimental Period ◽  
Energy Gain ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Maintenance Energy ◽  
Energy Retention ◽  
Maintenance Energy Requirement ◽  
Body Energy

1. Two diets, an all-roughage diet and a high-concentrate diet, were fed at two levels, a low level of estimated 1.5 times maintenance energy requirement and a higher level of estimated two times maintenance energy requirement, to South African Mutton Merino castrated male sheep, aged 13 months and in fairly lean condition at the start of the 93 d experimental period..2. Body composition and energy retention were determined using the comparative slaughter technique and two series of digestibility and balance studies were done during the course of the experiment. Metabolizability of each diet was estimated and corrected for fermentation heat using the fermentation balance approach..3. Although there were significantly different rates of energy gain on different diets and feeding levels, fat energy gained (% total energy gained) was similar for the four groups, i.e. 78–80..4. Regression of energy gain v. corrected metabolizable energy (ME) intake indicated that the maintenance energy requirements of sheep used in this experiment were 310.2 and 302.3 kJ ME/kg body-weight0.75 per d and the values for net utilization of ME for body energy gain were 0.411 and 0.479 with the roughage and concentrate diets respectively..5. It was concluded that the estimated maintenance energy requirements of sheep obtained in this study are realistic values and that the efficiency of utilization of surplus ME for the two diets did not differ significantly.

A note on the critical temperature of sucking rabbits

1989 ◽  
Vol 49 (2) ◽  
pp. 333-334
Author(s):  
E. Sanz ◽  
V. Ortiz ◽  
C. de Blas ◽  
M. J. Fraga
Keyword(s):  
Critical Temperature ◽  
Heat Production ◽  
Similar Rate ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Critical Temperatures ◽  
Ambient Temperatures ◽  
Energy Retention ◽  
Metabolizable Energy Intake ◽  
New Zealand Rabbits

Five hundred and fifty sucking New Zealand rabbits of three ages (1, 10 and 20 days) were used to measure metabolizable energy intake and heat production at five ambient temperatures varying between 12 and 36°C according to age. Critical temperatures and rate of heat production below them, decreased with age (32, 28 and 24°C; 20·8, 10·8 and 9·2 kJ/kg0·07 per day and °C at 1, 10 and 20 days of age respectively) as a result of the increase in thermal insulation. Energy retention also decreased below critical temperature at a similar rate to the increase of heat production, because rabbits could not increase their milk intake to meet their higher energy requirements.

Influence of body condition on maintenance energy requirements of Charolais cows

1993 ◽  
Vol 57 (1) ◽  
pp. 47-53 ◽  
Author(s):  
I. Ortigues ◽  
M. Petit ◽  
J. Agabriel
Keyword(s):  
Body Weight ◽  
Body Condition ◽  
Fat Body ◽  
Live Weight ◽  
Beef Cows ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Maintenance Energy ◽  
Body Fatness ◽  
Acid Detergent Fibre

AbstractThe objective of the experiment was to test whether maintenance energy requirements of non-lactating, non-pregnant beef cows increased with body fatness. Twelve Charolais cows were initially fed to attain either lean or fat body condition. Subsequently, over a period of 66 days food allowances were regularly adjusted for zero live-weight change. For the following 76 days, lean and fat cows received either 400 or 553 kJ metabolizable energy (ME) per kg initial live weight 0·75 per day, respectively. Fat cows maintained their body weight and composition whereas lean cows lost 296 g body weight, 221 g lipid and 65 g protein daily. Calculated maintenance energy requirements averaged 516 and 536kJ ME per kg live weight 0·75 per day for lean and fat cows respectively but were not significantly affected by body fatness. Diet dry matter, organic matter, crude protein and energy apparent digestibilities but not acid-detergent fibre digestibility were significantly higher in fat animals.

Effects of cimaterol on energy utilization for maintenance and for protein and fat deposition by wether and ewe lambs given chopped lucerne hay or lucerne-barley pellets

1990 ◽  
Vol 50 (1) ◽  
pp. 129-139 ◽  
Author(s):  
R. D. Sainz ◽  
J. E. Wolff ◽  
M. P. Upsdell
Keyword(s):  
Fat Deposition ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Energy Requirements ◽  
Quadratic Regression ◽  
Protein Deposition ◽  
Ewe Lambs ◽  
Energy Retention ◽  
Metabolizable Energy Intake ◽  
Diet Intake

ABSTRACTThe effects of sex (wethers v. ewes), diet (chopped lucerne hay v. lucerne-barley pellets) and cimaterol on energy utilization by Suffolk cross lambs were determined by comparative slaughter. Quadratic regression of energy retention (RE) on metabolizable energy intake (MEI) enabled estimation of maintenance energy requirements (Em), efficiencies of gain (ktotal) and maximum rates of gain (REMAX). Regressions using RE in fat and protein v. MEI yielded analogous parameters for fat and protein deposition (Em fat, kfat, REMAX fat and Emprotcin, kprolein, REMAXprotcin respectively). Em was lower in wethers than ewes (455 v. 510 kJ/kg M0·75 per day respectively), but was unaffected by diet or cimaterol. Sex and cimaterol did not affect ktotai. which was higher in lambs given pellets compared with lambs given hay (0·417 v. 0·224 respectively). Similarly, REMAX was higher in lambs given pellets than in lambs given hay (326 v. 114 kJ/kg 0·75 per day respectively). None of the groups differed significantly in the parameters of fat deposition, which averaged 480 kJ/kg 0·75 per day for Em fal, 0·224 for ktat, and 250 kJ/kg M0·75 per day for REMAX, fat- Em.protein was lower in wethers than in ewes (466 v. 569 kJ/kg 0·075 per day, respectively), and was further reduced by cimaterol (418 and 507 kJ/kg 0·75 per day for wethers and ewes respectively). Estimates of kprotcin were higher in wethers than in ewes (0·091 v. 0·064 respectively), and were increased by cimaterol (0·115 and 0·089 for wethers and ewes respectively). Similarly REMAX protein was higher in wethers than in ewes (47 v. 37 kJ/kg 0·75 per day respectively), and was increased by cimaterol (58 and 48 kJ/kg 0·75 per day for wethers and ewes respectively). The repartitioning action of cimaterol was additive with effects of diet, intake and sex.

Effects of plane of nutrition and environmental temperature on the growth and development of the early-weaned piglet 2. Energy metabolism

1984 ◽  
Vol 38 (2) ◽  
pp. 221-231 ◽  
Author(s):  
W. H. Close ◽  
M. W. Stanier
Keyword(s):  
Heat Loss ◽  
Energy Intake ◽  
Environmental Temperature ◽  
Fat Deposition ◽  
Metabolizable Energy ◽  
Maintenance Energy ◽  
Protein Deposition ◽  
Energy Retention ◽  
Metabolizable Energy Intake ◽  
Environmental Temperatures

ABSTRACT1. Measurements of heat loss, energy and nitrogen balance were made on 18 groups of piglets weaned at 2 weeks, at environmental temperatures of 18, 23 and 28°C, and at three levels of feeding at each temperature.2. From the experimental results, values of heat loss, energy retention, protein and fat deposition were derived for each temperature, at each of the three levels of metabolizable energy (kJ/kg M0·75 per day) intake: 550 (1·0MEm), 825 (1·5MEm) and 1100 (2·0MEm). The lowest of these levels was the calculated thermoneutral maintenance energy requirement (MEm).3. From the results the following deductions were made, (a) Heat loss varies with both environmental temperature and metabolizable energy intake, and at an intake of 2·0MEm is minimal between 23 and 28°C. Energy retention varies in an inverse manner to heat-loss, and at 1·0MEm is negative at all environmental temperatures below 28°C. (b) Protein and fat deposition increase significantly with increase in metabolizable energy intake (P < 0·05), with fat deposition being more dependent on temperature than protein deposition. The mean increase in protein deposition per 1°C increase in environmental temperature is 2·05 kJ/kg M0·75 per day. Fat deposition is negative at all temperatures at l·0MEm; at l·5MEm it is zero at 23°C and negative at temperatures below this.4. Critical temperature was calculated to decrease from 26·9°C at l·0MEm to 23·9°C at 2·0MEm.5. The efficiency of energy utilization (k) was 0·58 at 18°C, 0·81 at 23°C and 0·74 at 28°C. The corresponding values of the maintenance energy requirements were 739, 615 and 550 kJ/kg M0·75 per day. Estimates of the energetic efficiency of protein deposition (kp) of 0·60 to 0·65, and of fat deposition (k/) of 0·82 to 0·86, were determined at 23 and 28°C.

scholarly journals Requirements for maintenance and live weight gain of moose and wapiti calves during winter

Rangifer ◽  
1996 ◽  
Vol 16 (1) ◽  
pp. 41 ◽  
Author(s):  
Normand Cool ◽  
Robert J. Hudson
Keyword(s):  
Weight Gain ◽  
Energy Intake ◽  
Cervus Elaphus ◽  
Alces Alces ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Live Weight Gain ◽  
Metabolizable Energy Intake

Energy requirements of moose (Alces alces) and wapiti (Cervus elaphus) calves were compared from December to February to determine whether metabolic requirements were lower in a boreal-adapted than in a parkland-adapted wild cervid. Eight calves of each species were divided equally into groups given high or low quality diets. Regression of metabolizable energy intake on liveweight gain provided estimates for maintenance and gain, Metabolizable energy requirements for liveweight maintenance were 560 kj/kg0.75.d and for gain were 27 kj/g. Neither value was significantly different between moose and wapiti nor between genders within species. This similariry in winter metabolism and consistency with the interspecies mean suggests that winter metabolic dormancy is not necessarily an important part of a seasonal energetic strategy. The main difference was that moose calves maintained appetite and continued to grow throughout the winter.

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.

Responses to variations in dietary energy intakes by growing pigs 1. Estimates of digestible and metabolizable energy requirements for maintenance

1972 ◽  
Vol 15 (2) ◽  
pp. 111-116 ◽  
Author(s):  
J. L. Davies ◽  
I. A. M. Lucas
Keyword(s):  
Body Weight ◽  
Live Weight ◽  
Growing Pigs ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Dietary Energy ◽  
Digestible Energy ◽  
Significant Change

SUMMARYGroups of individually-fed pigs, each of three gilts and three castrates of mean live weights 18, 31, 46, 58, 72 and 80 kg, were given for 20 days feed allowances based on the ARC estimates of energy required for maintenance, assuming an efficiency of utilization of digestible energy (DE) of 77% for maintenance. As the actual diet used had a higher DE value than that calculated before the start of the experiment, DE intakes (260·3 W056) were about 4·0% above the ARC values.There was no statistically significant change in live weight over the period of study. This supports the validity of the ARC estimates, if maintenance is defined as a lack of change in body weight.The metabolizable energy (ME) intakes (248·3 W0·56) which maintained weight were also close to other estimates of ME requirements.

A two-diet system andad libitumlactation feeding of the sow 1. Sow performance

1996 ◽  
Vol 62 (2) ◽  
pp. 337-347 ◽  
Author(s):  
M. Neil ◽  
B. Ogle ◽  
K. Annèr
Keyword(s):  
Food Consumption ◽  
Post Partum ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Backfat Thickness ◽  
Conventional Diet ◽  
Feeding Regimes ◽  
Ad Libitum ◽  
The Difference ◽  
Depth Condition

AbstractEffects of a two-diet system combined withad libitumlactation feeding of sows on food consumption, sow live weight (LW), backfat depth, condition scoring, rebreeding interval, symptoms of agalactia and culling were studied on 60 sows followed for four parities. Feeding regimes were: CR, conventional i.e. restricted during gestation and lactation; SA, a simplified diet offered at a restricted level during gestation and a conventional dietad libitumduring lactation; CA, conventional during gestation and the same dietad libitumduring lactation. During lactation CR sows consumed 5·9 kg food daily (71 MJ metabolizable energy (ME)), whereas SA and CA sows consumed on average 7·0 kg (85 MJ ME), the difference being larger in multiparous than in primiparous sows and larger in the first than in later weeks of lactation. From the second farrowing onward sows on CR treatment were lighter and had thinner backfat and lower condition scores than sows on CA treatment, with sows on SA treatment in between, i.e. approaching the CR sows in the gestation periods and the CA sows in the lactation periods. At first service LW was 130 kg and backfat thickness 14 mm. During the fourth lactation LW averaged 190 kg in CR sows and around 220 kg for SA and CA sows, and backfat thickness was 11 mm in CR sows and around 16 mm in SA and CA sows. SA sows tended to rebreed earlier after weaning than did CR or CA sows. CA sows and in particular SA sows had higher incidences of agalactia symptoms and higher rectal temperatures post partum than CR sows. The culling rates did not differ between feeding regimes, although the predominant causes for culling did, being shoulder lesions and abscesses in thin CR sows and leg disorders in SA and CA sows. At the end of the experiment, however, more SA sows than others were retained in the experimental herd. It was concluded that the SA feeding regime was superior in terms of sow performance, despite an increased incidence of agalactia symptoms.

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