Foraging efficiency: energy expenditure versus energy gain in free-ranging black-tailed deer

1996 ◽  
Vol 74 (3) ◽  
pp. 442-450 ◽  
Author(s):  
Katherine L. Parker ◽  
Michael P. Gillingham ◽  
Thomas A. Hanley ◽  
Charles T. Robbins

Foraging efficiency (metabolizable energy intake/energy expenditure when foraging) was determined over a 2-year period in nine free-ranging Sitka black-tailed deer (Odocoileus hemionus sitkensis) in Alaska, and related to foraging-bout duration, distances travelled, and average speeds of travel. We calculated the energy-intake component from seasonal dry matter and energy content, dry matter digestibility, and a metabolizable energy coefficient for each plant species ingested. We estimated energy expenditures when foraging as the sum of energy costs of standing, horizontal and vertical locomotion, sinking depths in snow, and supplementary expenditures associated with temperatures outside thermoneutrality. Energy intake per minute averaged 4.0 times more in summer than winter; energy expenditure was 1.2 times greater in summer. Animals obtained higher amounts of metabolizable energy with higher amounts of energy invested. Energy intake during foraging bouts in summer was 2.5 times the energy invested; in contrast, energy intake during winter was only 0.7 times the energy expended. Changes in body mass of deer throughout the year increased asymptotically with foraging efficiency, driven primarily by the rate of metabolizable energy intake. Within a season, summer intake rates and winter rates of energy expediture had the greatest effects on the relation between foraging efficiency and mass status. Seasonal changes in foraging efficiency result in seasonal cycles in body mass and condition in black-tailed deer. Body reserves accumulated during summer, however, are essential for over-winter survival of north-temperate ungulates because energy demands cannot be met by foraging alone.

The Auk ◽  
2001 ◽  
Vol 118 (2) ◽  
pp. 519-524 ◽  
Author(s):  
Avner Anava ◽  
Michael Kam ◽  
Amiram Shkolnik ◽  
A. Allan Degen

Abstract Arabian Babblers (Turdoides squamiceps) are territorial, cooperative breeding passerines that inhabit extreme deserts and live in groups all year round. All members of the group feed nestlings in a single nest, and all group members provision at similar rates. Nestlings are altricial and fledge at about 12 to 14 days, which is short for a passerine of its body mass. Because parents and helpers feed nestlings, we hypothesized that the growth rate of nestlings is fast and that they fledge at a body mass similar to other passerine fledglings. Using a logistic growth curve, the growth rate constant (k) of nestlings was 0.450, which was 18% higher than that predicted for a passerine of its body mass. Asymptotic body mass of fledglings was 46 g, which was only 63% of adult body mass, a low percentage compared to other passerines. Energy intake retained as energy accumulated in tissue decreased with age in babbler nestlings and amounted to 0.29 of the total metabolizable energy intake over the nestling period. However, energy content per gram of body mass increased with age and averaged 4.48 kJ/g body mass. We concluded that our hypothesis was partially confirmed. Growth rate of babbler nestlings was relatively fast compared to other passerine species, but fledgling mass was relatively low.


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.


1977 ◽  
Vol 17 (86) ◽  
pp. 393
Author(s):  
DS Gillespie ◽  
JW McLaughlin

An experiment at Hamilton in western Victoria from June to October 1972 examined the feasibility of fattening two-year-old Corriedale wethers from 30 to 50 kg liveweight when fed simple rations in feedlots. Using a factorial design, treatments compared were mid-season or late cut pasture hay offered ad libitum and oat grain fed at 0, 0.25, 0.50 kg head-1 day-1 or ad libitum. Two additional groups were set stocked on green pasture; one of them was offered oat grain ad libitum. Performance of sheep in the feedlot (intake, liveweight and carcase gain, feed conversion and wool production) was influenced by hay type and level of oat feeding. Liveweight gain over the period of feeding increased linearly until oats comprised about 50 per cent of the daily dry matter intake, but the highest liveweight gain in the feedlot (127 g day-1) occurred when sheep were given a ration consisting of 25 per cent mid-season hay and 75 per cent oats. Sheep on pasture gained at an average of 146 g day-1. Irrespective of composition of the ration, liveweight gain increased by 20 g day1, carcase weight by 15 g day-1 and wool by 1.7 g day -1 for each additional MJ of metabolizable energy intake.


1991 ◽  
Vol 69 (8) ◽  
pp. 2128-2132 ◽  
Author(s):  
Scott R. Decker ◽  
Peter J. Pekins ◽  
William W. Mautz

Red oak acorns (Quercus rubra), fruits of multiflora rose (Rosa multiflora), common juniper (Juniper communis), winterberry holly (Ilex verticillata), and barberry (Berberis spp.), fertile fronds of sensitive fern (Onoclea sensibilis), corn, and apples were fed as mixed rations to eight eastern wild turkeys (Meleagris gallopavo silvestris). Crude protein content of the foods ranged from 2 (apples) to 19% (sensitive fern). Red oak acorns and juniper berries were 14% fat; other foods were 1–7% fat. Apples were lowest in gross energy content (3.9 kcal/g dry matter (1 cal = 4.1868 J)), and sensitive fern was highest (5.5 kcal/g). Little variation existed in nutrient composition and energy content of the mixed diets. Metabolizable energy values of the diets ranged from 65 to 84% of gross energy intake and from 3.1 to 4.0 kcal/g. Solution of simultaneous equations based on the mixed-diet data yielded metabolizable energy values of individual foods; juniper had the highest metabolizable energy (4.6 kcal/g) and sensitive fern the lowest (2.1 kcal/g); other foods ranged from 3.3 to 4.1 kcal/g. Acorns, corn, and shrubs with persistent fruits (juniper, winterberry, barberry, and multiflora rose) were the most nutritious foods. Metabolizable energy intake of the mixed diets, excluding the juniper-dominated diet, approximated or exceeded the predicted daily energy expenditure of wild turkeys.


2009 ◽  
Vol 89 (6) ◽  
pp. 1744-1750 ◽  
Author(s):  
Rajni Singh ◽  
Berdine R Martin ◽  
Yvonne Hickey ◽  
Dorothy Teegarden ◽  
Wayne W Campbell ◽  
...  

1970 ◽  
Vol 12 (3) ◽  
pp. 413-418 ◽  
Author(s):  
M. Kay ◽  
N. A. MacLeod ◽  
Margaret McLaren

SUMMARY1. A growth and digestibility trial was carried out with 27 British Friesian calves given diets having either 3·1, 2·8 or 2·4 Meal metabolizable energy per kg dry matter and either the same concentration of protein or the same protein-to-energy ratio.2. Daily dry-matter intake and rate of gain in live weight increased significantly as the energy concentration of the diet was reduced. There were no significant differences in digestible-energy intake between calves given the different diets, although the trend was the same as for dry-matter intake.3. Both dry-matter digestibility and energy digestibility were lowest for the low-energy diet.


2004 ◽  
Vol 78 (2) ◽  
pp. 293-303 ◽  
Author(s):  
Z. Fuller ◽  
C. A. Maltin ◽  
E. Milne ◽  
G.S. Mollison ◽  
J. E. Cox ◽  
...  

AbstractEvaluations of the energy requirements of working animals have been confounded by the constraints of indirect calorimetric techniques (Cal). This study sought to investigate a non-restrictive methodology, the doubly labelled water (DLW; 2H218O) technique, for the measurement of energy expenditure in free ranging equids. Six pony geldings were intravenously injected with DLW in two sequential studies that permitted first, isotope equilibration and half-lives to be determined and then second, heat production (HP) to be measured simultaneously by DLW and traditional (Cal) techniques.In study 1, three animals were injected with DLW, three animals were untreated controls. Blood samples were collected every 30 min for 12 h and thereafter at 24 h intervals for 14 days. Isotopes equilibrated throughout the body water pool within 300 (2H) and 240 (18O) min and half-lives were 6.3 ± 0.6 days (2H) and 5.6 ± 0.4 days (18O).In study 2, HP was simultaneously determined by Cal and DLW over a 4-day period. Animals (no. = 6) were assigned to pairs and in successive weeks two ponies were injected with DLW and confined to metabolism chambers 12 h later. Cal HP was 0.51 ± 0.02 MJ/kg M0.75 per day compared with 0.48 ± 0.29 MJ/kg M0.75 per day estimated by DLW. Maintenance metabolizable energy intake was 0.53 ± 0.01 MJ/kg M0.75 per day (Cal) and 0.50 ± 0.01 MJ/kg M0.75 per day (DLW). Validation of the DLW technique may empower essential, systematic appraisal of energy requirements in unrestrained working horses.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246208
Author(s):  
Helena Ferreira Lage ◽  
Ana Luiza da Costa Cruz Borges ◽  
Ricardo Reis e Silva ◽  
Alan Maia Borges ◽  
José Reinaldo Mendes Ruas ◽  
...  

The purpose of this study was to determine the energy partition of pregnant F1 Holstein x Gyr with average initial body weight (BW) of 515.6 kg and Gyr cows with average initial BW of 435.1 kg at 180, 210 and 240 days of gestation, obtained using respirometry. Twelve animals in two groups (six per genetic group) received a restricted diet equivalent to 1.3 times the net energy for maintenance (NEm). The proportion of gross energy intake (GEI) lost as feces did not differ between the evaluated breeds and corresponded to 28.65% on average. The daily methane production (L/d) was greater for (P<0.05) F1 HxG compared to Gyr animals. However, when expressed as L/kg dry matter (DM) or as percentage of GEI there were no differences between the groups (P>0.05). The daily loss of energy as urine (mean of 1.42 Mcal/d) did not differ (P>0.05) between groups and ranged from 3.87 to 5.35% of the GEI. The metabolizable energy intake (MEI) of F1 HxG animals was greater (P < 0.05) at all gestational stages compared to Gyr cows when expressed in Mcal/d. However, when expressed in kcal/kg of metabolic BW (BW0,75), the F1 HxG cows had MEI 11% greater (P<0.05) at 240 days of gestation and averaged 194.39 kcal/kg of BW0,75. Gyr cows showed no change in MEI over time (P>0.05), with a mean of 146.66 kcal/kg BW0. 75. The ME used by the conceptus was calculated by deducting the metabolizable energy for maintenance (MEm) from the MEI, which was obtained in a previous study using the same cows prior to becoming pregnant. The values of NEm obtained in the previous study with similar non-pregnant cows were 92.02 kcal/kg BW0.75 for F1 HxG, and 76.83 kcal/kg BW0.75 for Gyr (P = 0.06). The average ME for pregnancy (MEp) was 5.33 Mcal/d for F1 HxG and 4.46 Mcal/d for Gyr. The metabolizability ratio, averaging 0.60, was similar among the evaluated groups (P>0.05). The ME / Digestible Energy (DE) ratio differed between groups and periods evaluated (P<0.05) with a mean of 0.84. The heat increment (HI) accounted for 22.74% and 24.38% of the GEI for F1 HxG and Gyr cows, respectively. The proportion of GEI used in the basal metabolism by pregnant cows in this study represented 29.69%. However, there were no differences between the breeds and the evaluation periods and corresponded to 29.69%. The mean NE for pregnancy (NEp) was 2.76 Mcal/d and did not differ between groups and gestational stages (P>0.05).


2016 ◽  
Vol 46 (10) ◽  
pp. 1852-1857 ◽  
Author(s):  
Jorge Cunha Lima Muniz ◽  
Sérgio Luiz de Toledo Barreto ◽  
Raquel Mencalha ◽  
Gabriel da Silva Viana ◽  
Renata de Souza Reis ◽  
...  

ABSTRACT: This trial was carried out to evaluate the effects of dietetic metabolizable energy levels on performance and carcass traits of meat quails from 15 to 35 days old. Five hundred sixty, 15-d old, meat quails were randomly assigned to five treatments (2.850; 2.950; 3.050; 3.150 e 3.250kcal of ME kg-1 of diet), with eight replicates and fourteen birds per experimental unit. Feed intake, protein and lysine intake and feed conversion decreased linearly as the metabolizable energy content of diets increased (P<0.01), whereas metabolizable energy intake, body weight, weight gain and viability were not affected (P>0.05) by the treatments. Diets did not influence (P>0.05) carcass traits as dry matter, moisture and protein content in carcass. However a quadratic effect (P<0.04) were observed on carcass fat content. Based on these results, the adequate metabolizable energy level to ensure better meat quails' growth is 3.250kcal of ME kg-1 diet, that corresponds to a metabolizable energy: crude protein ratio of 139,24.


1979 ◽  
Vol 29 (2) ◽  
pp. 245-255 ◽  
Author(s):  
D. J. Thomson ◽  
S. B. Cammell

ABSTRACTA primary growth crop of perennial ryegrass (cv. S24), containing 17% crude protein and 9·9 MJ metabolizable energy/kg dry matter, was artificially dried, ground through a 3·0 mm screen and pelleted either without further treatment (C), or after the application of formaldehyde (T) at a rate of 1 g/100 g crude protein. The C and T diets were each fed to 20 lambs for 77 days. Diets C and T were given ad libitum and at three lower planes of nutrition. Similar amounts of dry matter, nitrogen and digestible energy were consumed at each of the four planes of nutrition by lambs fed diets C and T. Carcass energy, fat and protein retention, and total body energy retention were measured by the comparative slaughter technique and did not differ between the diets (P> 0·05). Metabolizable energy intake was calculated from digestible energy intake using the factor 0·81. The efficiency of utilization of the metabolizable energy for growth and fattening (kf) and the net energy value were calculated by linear regression analysis from the total body energy retention, the calculated metabolizable energy intake and dry-matter intake data scaled to M0·75. They did not differ between the diets (P > 0·05), and were 0·370 (C) and 0·431 (T) for kf, and 2·09 (C) and 1·97 MJ/kg dry matter (T) for net energy.


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