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

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.

1984 ◽  
Vol 38 (2) ◽  
pp. 221-231 ◽  
Author(s):  
W. H. Close ◽  
M. W. Stanier

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.


1989 ◽  
Vol 49 (2) ◽  
pp. 333-334
Author(s):  
E. Sanz ◽  
V. Ortiz ◽  
C. de Blas ◽  
M. J. Fraga

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.


1999 ◽  
Vol 69 (1) ◽  
pp. 191-202 ◽  
Author(s):  
C. McG. Argot ◽  
J. S. Smith ◽  
R. N. B. Kay

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.


1985 ◽  
Vol 53 (2) ◽  
pp. 267-279 ◽  
Author(s):  
W. H. Close ◽  
J. Noblet ◽  
R. P. Heavens

1. The heat losses and energy and nitrogen balances of pregnant gilts, and of their non-pregnant litter sisters (controls), were measured for periods of 7 d at feed intakes of 1.8 or 2 3 kg/d (20 or 30 MJ metabolizable energy (ME) respectively) at an environmental temperature of 20°. The measurements were made within three separate periods of gestation; 40–60 d (early), 60–80 d (mid) and 90–110 d (late). Values for ME intake, heat loss, energy retention (ER), protein deposition and fat deposition were determined for both the pregnant and control animals on each treatment.2. When expressed per kg body-Weight 0.75 per d, there was little difference in heat loss between pregnant and non-pregnant animals and between pregnant animals at the different stages of gestation at any given ME intake. However, heat loss was higher at the higher ME intake.3. ER vaned inversely with heat loss. The decrease in ME intake (kJ/kg body-Weight 0.75 per d) during pregnancy resulted in a decrease in ER so that the pregnant animals were in negative energy balance at the low feed intake during late gestation. From the relation between ER and ME intake, estimates of the maintenance energy requirement (MEm) of 411 and 401 kJ/kg body-weight0.75 per d were calculated, with corresponding partial efficiencies of energy utilization (k) of 0.74 and 0.68 for the pregnant and non-pregnant animals respectively.4. For the pregnant animals, protein deposition was highest during mid-pregnancy and was relatively independent of level of feeding during mid- and late pregnancy. There was little difference in protein deposition between pregnant and non-pregnant animals at the high feed intake. At the low feed intake, the pregnant animals generally had a higher protein deposition than their non-pregnant litter sisters and this was entirely associated with the accretion in reproductive tissue.5. Fat deposition depended on the level of feeding, and at any given ME intake was similar for pregnant and control animals. In late gestation the low level of feeding was insufficient to prevent the pregnant animals losing fat. It was calculated that at term these animals lost 140 g fat/d from maternal stores.6. From the relation between ME intake and protein and fat deposition, estimates of ME, and the energetic efficiencies of protein (k,) and fat (k,) deposition were determined. There was little difference in ME, (422 and 420 kJ/kg body-weight 0.5 per d) and k, (0.88 and 0.90) between pregnant and non-pregnant animals respectively. However, the pregnant animals had a higher k, (0.69 compared with 0.49 for controls) and this reflected the higher rates of protein deposition associated with pregnancy.7. The efficiency of energy deposition in the reproductive tissue was calculated to be 0.72.


2002 ◽  
Vol 138 (2) ◽  
pp. 221-226 ◽  
Author(s):  
A. ALLAN DEGEN ◽  
B. A. YOUNG

Body mass was measured and body composition and energy requirements were estimated in sheep at four air temperatures (0 °C to 30 °C) and at four levels of energy offered (4715 to 11785 kJ/day) at a time when the sheep reached a constant body mass. Final body mass was affected mainly by metabolizable energy intake and, to a lesser extent, by air temperature, whereas maintenance requirements were affected mainly by air temperature. Mean energy requirements were similar and lowest at 20 °C and 30 °C (407·5 and 410·5 kJ/kg0·75, respectively) and increased with a decrease in air temperature (528·8 kJ/kg0·75 at 10 °C and 713·3 kJ/kg0·75 at 0 °C). Absolute total body water volume was related positively to metabolizable energy intake and to air temperature. Absolute fat, protein and ash contents were all affected positively by metabolizable energy intake and tended to be related positively to air temperature. In proportion to body mass, total body water volume decreased with an increase in metabolizable energy intake and with an increase in air temperature. Proportionate fat content increased with an increase in metabolizable energy intake and tended to increase with an increase in air temperature. In contrast, proportionate protein content decreased with an increase in metabolizable energy intake and tended to decrease with an increase in air temperature. In all cases, the multiple linear regression using both air temperature and metabolizable energy intake improved the fit over the simple linear regressions of either air temperature or metabolizable energy intake and lowered the standard error of the estimate. The fit was further improved and the standard error of the estimate was further lowered using a polynomial model with both independent variables to fit the data, since there was little change in the measurements between 20 °C and 30 °C, as both air temperatures were most likely within the thermal neutral zone of the sheep. It was concluded that total body energy content, total body water volume, fat and protein content of sheep of the same body mass differed or tended to differ when kept at different air temperatures.


1964 ◽  
Vol 15 (1) ◽  
pp. 127 ◽  
Author(s):  
N McCGraham

At intervals throughout gestation, the energy, carbon, and nitrogen exchanges of four Merino ewes were determined with the aid of closed-circuit indirect calorimetry. Six similar but non-pregnant animals were studied at the same time. The food consisted of equal parts of lucerne and wheaten hay; half the sheep in each group were given a constant 600 g/day and half 900 g/day, and the non-pregnant ewes were fasted on one occasion. Free fatty acids, glucose, and ketones in the blood were also determined during the final stages of pregnancy. Balance measurements were continued during lactation, the ewes being given 1200 g food/day for the first month and 900 g for the second. The digestibility of the food was not affected by pregnancy or lactation, but urinary nitrogen loss decreased as pregnancy advanced and was least during lactation. Although a constant amount of food was eaten, the heat production of each pregnant animal increased throughout gestation. The heat increment of pregnancy at term was 90 kca1/24 hr/kg foetal tissue. The most direct measurements of oxygen uptake by the foetus in utero indicate much lower levels of heat production per kilogram of tissue; it is concluded that these are underestimates. The metabolic rate was unusually high immediately before parturition, and in two cases decreased to near non-pregnant levels 24 hr after lambing. The total energy retention of the ewes became smaller as pregnancy advanced, and in two cases was negative at term. Metabolizable energy was used for reproduction with a gross efficiency of 15–22% and a net efficiency of 13%. The metabolizable energy used per kilogram of foetus was approximately 10% of the maintenance requirement of the ewe herself. Daily energy utilization by the conceptus at term probably accounted for 70% of the glucogenic substances available from the food. There was no evidence of increased gluconeogenesis from protein by the pregnant ewe. The nutrition of the ewe during gestation affected lactation mainly in the first week or two. The data indicate that nitrogen intake rather than energy intake limited milk production. Irrespective of the amount of energy in the milk, the heat increment due to feeding was 20% smaller for lactating than for dry fatteningewes. It is suggested that efficient use of acetate by the mammary gland permits more efficient lipogenesis by other tissues.


1969 ◽  
Vol 72 (3) ◽  
pp. 479-489 ◽  
Author(s):  
D. W. F. Shannon ◽  
W. O. Brown

SUMMARYExperiments to determine the net availabilities of the metabolizable energy (NAME) of a cereal-based diet and a maize-oil diet for maintenance and lipogenesis and the effect of environmental temperature on the NAME of the cereal-based diet are described. Four 1- to 2-year-old Light Sussex cockerels were used.The relationship between ME intake and energy retention was linear for each diet. The NAME'S of the cereal-based diet given at 22° and 28 °C (70.6 ± 1.83 % and 73.6 ± 3.54%, respectively) were significantly (P < 0.05) lower than the NAME of the maize-oil diet (84.1 ± 1.85%). It is concluded that the beneficial effect of maize oil on the efficiency of energy utilization is due to a reduced heat increment rather than a reduction in the basal component of the heat production. The higher efficiency from the maize-oil diet led to an increase in the energy retained as fat.The mean fasting heat production at 28 °C was 15 % lower than at 22 °C (43.2 ± 1.45 and 51.2 ± 1.09 kcal/kg/day, respectively). The NAME of the cereal-based diet was not significantly different when the birds were kept at 22° or 28 °C. The lower metabolic rate at 28 °C was reflected in a lower maintenance requirement and in an increase in the deposition of body fat.


1979 ◽  
Vol 41 (1) ◽  
pp. 223-229 ◽  
Author(s):  
D. J. Thomson ◽  
J. S. Fenlon ◽  
S. B. Cammell

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.


1991 ◽  
Vol 52 (3) ◽  
pp. 535-543 ◽  
Author(s):  
S. A. Beech ◽  
R. Elliott ◽  
E. S. Batterham

ABSTRACTAn experiment was conducted to determine the effect of sucrose as an energy source on energy utilization and protein retention by growing pigs. Growing pigs (20 to 50 kg live weight) were restrictively fed (three times maintenance) either a control wheat-based diet (14 MJ digestible energy (DE) per kg), a sucrose-based diet (15 MJ DE per kg) or a wheat-based diet made i so-energetic with the sucrose diet by the addition of oil. Net energy (NE) content of the diet, energy utilization, protein and fat deposition were measured.Both the sucrose- and the iso-energetic wheat-based diets improved energy utilization and increased NE retention. They also increased fat deposition (P < 0·05) but had no effect on protein deposition (P > 0·05) compared with the wheat-based control. Increased DE utilization in the sucrose-based diet appeared due to (i) lower dietary fibre, (ii) a better balance of amino acids, or possibly due to (iii) increased fat synthesis due to sucrose metabolism. The lack of effect of sucrose on protein deposition appeared due to either (i) an increased amino acid requirement as a result of the higher NE content of the diet or (ii) preferential use of sucrose for fat deposition.


2019 ◽  
Vol 3 (3) ◽  
pp. 999-1010
Author(s):  
Izabelle A M A Teixeira ◽  
Amélia K Almeida ◽  
Márcia H M R Fernandes ◽  
Kleber T Resende

Abstract The aim of this review is to describe the main findings of studies carried out during the last decades applying the California net energy system (CNES) in goats. This review also highlights the strengths and pitfalls while using CNES in studies with goats, as well as provides future perspectives on energy requirements of goats. The nonlinear relationship between heat production and metabolizable energy intake was used to estimate net energy requirements for maintenance (NEm). Our studies showed that NEm of intact and castrated male Saanen goats were approximately 15% greater than female Saanen goats. Similarly, NEm of meat goats (i.e., &gt;50% Boer) was 8.5% greater than NEm of dairy and indigenous goats. The first partial derivative of allometric equations using empty body weight (EBW) as independent variable and body energy as dependent variable was used to estimate net energy requirements for gain (NEg). In this matter, female Saanen goats had greater NEg than males; also, castrated males had greater NEg than intact males. This means that females have more body fat than males when evaluated at a given EBW or that degree of maturity affects NEg. Our preliminary results showed that indigenous goats had NEg 14% and 27.5% greater than meat and dairy goats, respectively. Sex and genotype also affect the efficiency of energy use for growth. The present study suggests that losses in urine and methane in goats are lower than previously reported for bovine and sheep, resulting in greater metabolizable energy:digestible energy ratio (i.e., 0.87 to 0.90). It was demonstrated that the CNES successfully works for goats and that the use of comparative slaughter technique enhances the understanding of energy partition in this species, allowing the development of models applied specifically to goat. However, these models require their evaluation in real-world conditions, permitting continuous adjustments.


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