Metabolism and growth of young harp and grey seals

1987 ◽  
Vol 65 (6) ◽  
pp. 1377-1382 ◽  
Author(s):  
Graham A. J. Worthy

Metabolic rates and growth rates of juvenile harp and grey seals were monitored during the postweaning period after the onset of feeding. Growth rates varied from 0.03 to 0.32 kg d−1, depending on the level of energy intake and absolute body mass of the seal. Measurements of sculp mass (blubber with attached skin), as a percentage of total mass, indicated low rates of growth in the sculp and preferential growth in the core. When feeding started there was a 1.3- to 2.3-fold increase in standard metabolic rate, which was independent of the heat increment of feeding. Metabolic requirements of feeding seals, measured by indirect calorimetry, were between 1.2 and 7.2 W kg−1 in water and between 1.2 and 6.0 W kg−1 in air, similar to average daily metabolic rates calculated from net energy intake.

1986 ◽  
Vol 64 (2) ◽  
pp. 322-327 ◽  
Author(s):  
Lyle A. Renecker ◽  
Robert J. Hudson

Metabolic rates and thermoregulatory responses were studied in adult moose (Alces alces) exposed to various ambient temperatures during winter and summer. Resting energy expenditures followed a marked annual cycle with a maximum (940 kJ kg body weight−0.75 d−1) during spring – early summer and minimum (430 kJ kg body weight−0.75 d−1) during winter. The heat increment of feeding associated with a pelleted ration was 6–9 kJ kg body weight−0.75 h−1. The energy cost of standing was 4.2 kJ kg body weight−0.75 h−1, an increment of 25% over the lying posture. Although piloerection was observed between −25 and −30 °C, metabolic rates did not increase. In contrast to their cold tolerance, moose were easily heat stressed. During winter, moose increased respiration rates when ambient temperatures rose above −5 °C. Resistance to heat load was greater for standing moose during summer; respiration rate increased above 14 °C and open-mouthed panting began at 20 °C. Energy expenditure and heart rate followed a similar rise with increasing ambient temperature.


1999 ◽  
Vol 77 (2) ◽  
pp. 314-320 ◽  
Author(s):  
C L Gass ◽  
M T Romich ◽  
R K Suarez

Because of their small size and the high energetic costs of hovering and forward flight, hummingbirds achieve the highest mass-specific metabolic rates known among vertebrates. Rufous hummingbirds (Selasphorus rufus) stop to refuel on floral nectar in subalpine meadows as they migrate south from British Columbia to Mexico. In such habitats they face the challenge of achieving daily net energy gain despite the high energetic costs of flight and thermoregulation at near-freezing morning temperatures. Hummingbirds provided with 15 or 20% sucrose while subjected to these conditions for 4 h in the laboratory did not remain in energy balance and lost mass. However, they achieved energy balance or net energy gain on 30% sucrose. Because these sucrose concentrations are within the range observed in the nectar of hummingbird-visited flowers, the results suggest that the energetic cost of thermoregulation may influence the coevolution of hummingbirds and flowers. Hummingbirds maintaining energy balance at low ambient temperature via high foraging frequencies and high rates of energy intake can sustain average metabolic rates of about 250 W/kg over a 4-h period. These are the highest metabolic rates known among vertebrates at which rates of dietary energy intake equal rates of energy expenditure.


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).


2009 ◽  
Vol 276 (1664) ◽  
pp. 2103-2108 ◽  
Author(s):  
K.J. Millidine ◽  
J.D. Armstrong ◽  
N.B. Metcalfe

Basal or standard metabolic rate (SMR) has been found to exhibit substantial intraspecific variation in a range of taxa, but the consequences of this variation are little understood. Here we explore how SMR is related to the energy cost of processing food, known as apparent specific dynamic action or the heat increment of feeding. Using juvenile Atlantic salmon Salmo salar , we show that fishes with a higher SMR had a higher peak and a greater total energy expenditure when digesting a given size of meal. However, the duration over which their metabolism was elevated after consuming the meal was shorter. The greater energy costs they incur for processing food may be related to their assimilation efficiency. These relationships are likely to have implications for feeding strategies and growth rates, since individuals with a higher SMR have higher routine costs of living but recover more quickly following feeding and so may have a greater potential for processing food.


2016 ◽  
Vol 94 (2) ◽  
pp. 123-135 ◽  
Author(s):  
Mariana Diaz Gomez ◽  
David A.S. Rosen ◽  
Andrew W. Trites

Understanding whether northern fur seals (Callorhinus ursinus (L., 1758)) are negatively affected by changes in prey quality or diversity could provide insights into their on-going population decline in the central Bering Sea. We investigated how six captive female fur seals assimilated energy from eight different diets consisting of four prey species (walleye pollock (Gadus chalcogrammus Pallas, 1814, formerly Theragra chalcogrammus (Pallas, 1814)), Pacific herring (Clupea pallasii Valenciennes in Cuvier and Valenciennes, 1847), capelin (Mallotus villosus (Müller, 1776)), and magister armhook squid (Berryteuthis magister (Berry, 1913))) fed alone or in combination. Net energy was quantified by measuring fecal energy loss, urinary energy loss, and heat increment of feeding. Digestible energy (95.9%–96.7%) was high (reflecting low fecal energy loss) and was negatively affected by ingested mass and dietary protein content. Urinary energy loss (9.3%–26.7%) increased significantly for high-protein diets. Heat increment of feeding (4.3%–12.4%) was significantly lower for high-lipid diets. Overall, net energy gain (57.9%–83.0%) was affected by lipid content and varied significantly across diets. Mixed-species diets did not provide any energetic benefit over single-species diets. Our study demonstrates that diet quality was more important in terms of energy gain than diet diversity. These findings suggest that fur seals consuming low-quality prey in the Bering Sea would be more challenged to obtain sufficient energy to satisfy energetic and metabolic demands, independent of high prey abundance.


2013 ◽  
Vol 216 (21) ◽  
pp. 4109-4123 ◽  
Author(s):  
R. E. Whitlock ◽  
A. Walli ◽  
P. Cermeno ◽  
L. E. Rodriguez ◽  
C. Farwell ◽  
...  

1989 ◽  
Vol 54 (11) ◽  
pp. 2951-2961 ◽  
Author(s):  
Miloslav Karel ◽  
Jaroslav Nývlt

Measured growth and dissolution rates of single crystals and tablets were used to calculate the overall linear rates of growth and dissolution of CuSO4.5 H2O crystals. The growth rate for the tablet is by 20% higher than that calculated for the single crystal. It has been concluded that this difference is due to a preferred orientation of crystal faces on the tablet surface. Calculated diffusion coefficients and thicknesses of the diffusion and hydrodynamic layers in the vicinity of the growing or dissolving crystal are in good agreement with published values.


1976 ◽  
Vol 56 (3) ◽  
pp. 523-529 ◽  
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY

A total of 13,561 Holstein 305-day lactation records were studied to examine the effects of correcting records for linear and quadratic effects of 305-day net energy intake from silage, hay, pasture and meal feeding on estimates of genetic parameters of milk, fat and protein yield and fat and protein percent. Correcting records for net energy intake reduced variances of yield traits, but had little effect on composition trait variances. When expressed as a percentage of the total variance, the relative importance of sire and sire–herd components were unchanged using corrected records, and heritabilities, except for that of protein yield, were unaltered. Cow components of yield traits were reduced relative to other components after records were corrected for feeding levels. Consequently, repeatabilities were reduced as well, suggesting that a large portion of the permanent environmental effects on yield traits may be of nutritional origin. Genetic and phenotypic correlations between yield traits were also reduced appreciably after records were corrected for feed intake. Genetic relationships between milk, fat and protein yield may not be as great as commonly believed.


Nature ◽  
1969 ◽  
Vol 223 (5202) ◽  
pp. 213-213 ◽  
Author(s):  
M. J. STOCK

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