scholarly journals Growth rate and body size differences in Rangifer, a study of causes and effects

Rangifer ◽  
1983 ◽  
Vol 3 (1) ◽  
pp. 3 ◽  
Author(s):  
Eigil Reimers

<p>The paper discusses growth rate- and body size differences in Rangifer; their causes and effects. Growth rates and autumn body weights vary considerably both within and between Rangifer subspecies. The variation measured is within limits found in animals of same genetical stock subjected to different environments. Reproductive age, pregnancy rate, calving time and mortality either are or may be functionally related to autumn body weights. The differences in growth rates and body size among Rangifer in different areas are caused primarily by differences in environmental factors during the summer, including stress. The quality of the winter pastures has a minor effect on the body size in areas where the summer conditions allow the animals to grow at their maximum rate. In areas where maximum growth rates for various reasons are counteracted, severely overgrazed winter pastures will contribute to reduced body size. Stress in the terms of human disturbance, insects and predators and the effect on Rangifer activity pattern and hence on growth rates and body size need to be more thoroughly dealt with.</p><p>Forskjeller i vekst og st&oslash;rrelse hos Rangifer, en studie over &aring;rsaker og virkninger.</p><p>Abstract in Norwegian / Sammendrag: Arbeidet diskuterer &aring;rsaker til og virkninger av vekst- og st&oslash;rrelsesforskjeller hos Rangifer. Vekst og h&oslash;stvekter varierer betydelig b&aring;de innen og mellom de enkelte &AElig;angj/er-underartene. Variasjonene er imidlertid ikke st&oslash;rre enn de som er beskrevet i bestander med samme genetiske utgangspunkt og utsatt for ulike milj&oslash;forhold. Alder ved kj&oslash;nnsmodning, drektighetsfrekvens, kalvingstid og d&oslash;delighet er eller synes &aring; v&aelig;re relatert til h&oslash;stvektene. Vekst-og st&oslash;rrelsesforskjeller hos rein og caribou i ulike omr&aring;der skyldes i f&oslash;rste rekke forskjeller i milj&oslash;faktorene om sommeren, stress inkludert. Kvaliteten av vinterbeitene har liten effekt p&aring; kroppsst&oslash;rrelse i omr&aring;der hvor forholdene sommerstid tillater maksimal veksthastighet. I omr&aring;der hvor dette av forskjellige grunner ikke skjer, vil sterkt overbeitede vinterbeiter bidra til reduserte kroppsvekter. Stress i form av menneskelige forstyrrelser, insekter og rovdyr og effekten p&aring; reinens/caribouens aktivitetsbudsjett og derigjennom p&aring; vekst og kroppsvekt har krav p&aring; st&oslash;rre forskningsinteresse.</p><p>Rangiferin kasvun ja suuruuden eroavaisuuksia. Tutkielma syist&aring; ja vaikutuksista.</p><p>Abstract in Finnish / Yhteenveto: Tyo k&aring;sittelee syit&aring; ja vaikutuksia Rangiferin kasvu - ja suuruuseroavaisuuksista. Kasvu ja syyspainot vaihtelevat huomattavasti sek&aring; yksitt&aring;isiss&aring; Rangifer - alalajeissa ett&aring; lajien kesken. Vaihtelu ei ole kuitenkaan suurempi kuin se mit&aring; on kerrottu laumoista, joilla on sama perinnollinen l&aring;htokohta ja jotka ovat joutuneet erilaisten ymparistotekijoiden vaikuttamiksi. Sukukypsyysik&aring;, tiinehtyvyystaajuus, vasonta-aika ja kuolleisuus on tai n&aring;ytt&aring;&aring; olevan suhteessa syyspainoihin. Syy kasvu - ja suuruuseroavaisuuksiin poroilla ja karibulla eri seuduilla n&aring;ytt&aring;&aring; ensi sijassa olevan ymp&aring;ristotekijoiden eroavaisuudet kes&aring;ll&aring;, stressi mukaanluettuna. Talvilaitumien laadulla on pieni vaikutus ruumiin suuruuteen seuduilla, joissa olosuhteet kes&aring;aikaan sallivat enimm&aring;iskasvunopeuden. Seuduilla, joissa t&aring;ta ei tapahdu - eri syist&aring; johtuen, voimakkaasti ylirasitetut talvilaitumet vaikuttavat alentuneisiin ruumiinpainoihin. Stressi, inhimillisten h&aring;irioden muodossa, hyonteiset ja petoel&aring;imet ja poron/karibun vaikutus toimintaan sek&aring; siten kasvuun ja ruumiinpainoon ovat seikkoja, jotka vaativat suurempaa tutkimuskiinnostusta.</p>

Author(s):  
D.F. Houlihan ◽  
K. Kelly ◽  
P.R. Boyle

Octopuses (Eledone cirrhosa (Octopoda: Cephalopoda)) held in an aquarium were subjected to varying conditions of feeding and starvation to evaluate putative indices of feeding and growth. Specific growth rate (%d−1) was linearly related to feeding rate (% of the body mass d−1) in animals with a mean body mass of 250 g at 15°C. Maximum growth rates varied between > 2% d−1 (body weights < 300 g) to < 1% d−1 (body weights ≤ 900 g) but specific growth rates were not related to body weight. Growth rates became negative (weight loss) after one week without food.The digestive gland index (DGI) was significantly correlated with short and long-term feeding and specific growth rates, and with body weight. Muscle RNA concentration was linearly correlated with growth rate during the previous 1–3 weeks but not with feeding rate. RNA:protein ratios were not different between mid-arm and mantle sample sites but arm tip values were significantly higher. RNA:protein ratio was related to body weight only in feeding animals. It is concluded that DGI is an index of feeding rate and that RNA:protein ratio can be used as an index of recent (~ 4 weeks) growth rate.


1980 ◽  
Vol 94 (1) ◽  
pp. 95-104 ◽  
Author(s):  
G. J. Rowlands

SummaryBlood samples were taken at 9, 10 and 11 weeks of age from 230 male Hereford × Friesian calves, the progeny of 12 Hereford bulls. Concentrations of blood glucose, serum albumin, inorganic phosphate and sodium were measured and correlated with body weights and growth rates until slaughter at 19½ months of age.Correlations between growth rates and glucose concentrations (0·44) and between growth rates and albumin concentrations (0·38) were observed until 4 months of age. Similar correlations between body weights and blood glucose or albumin concentrations persisted until 6 months of age. By 10 months, however, the correlations had begun to decline, and by slaughter they had become insignificant.Correlations between growth rates and inorganic phosphate or sodium concentrations were smaller, and also decreased with age.The effect of hypoglycaemia on growth rate was compared with the effect of enzootic pneumonia. Although the 10% of calves with the lowest glucose concentrations were growing 24% more slowly than the other calves at the time of sampling, this growth depression was not related to pneumonia, and they subsequently made up for most of the early loss of growth.Three blood samples were also taken from 22 Hereford bulls. No significant correlations were observed between the blood composition of the bulls and the body weights or weight gains of their progeny.


1994 ◽  
Vol 6 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Robert M. Malina

The growth status and rate of a mixed-longitudinal sample (N = 19) of female volleyball players 9–13 years of age were compared to reference data for the general population. The athletes were measured at the beginning and end of the school year. Growth rates in stature and weight adjusted to 6-month intervals were calculated. The results indicate mean statures that are above U.S. reference medians and mean weights that are near the medians (i.e., tall girls with average body weights). Estimated half-year growth rates in stature and weight from 10.0–13.0 years closely match the respective medians of the Fels longitudinal study. The data thus suggest that the larger body size of young volleyball players is not a function of accelerated growth rate during these early adolescent ages and, thus, not due to earlier maturation; body size is likely genotypic and probably reflects selection at relatively young ages for the size demands of the sport.


1969 ◽  
Vol 62 (2) ◽  
pp. 367-384 ◽  
Author(s):  
A. M. Sackler ◽  
A. S. Weltman ◽  
R. Schwartz ◽  
P. Steinglass

ABSTRACT This report was designed to determine combined effects of maternal endocrine imbalances and abnormal behaviour due to prolonged isolation stress of female mice on the behaviour, developmental growth rate and endocrine function of their offspring. Sixty female albino mice averaging 19 g were divided equally into isolated and control groups. The isolated females were housed singly; control females were maintained in groups of 2 mice per cage. After observation of behavioural and physiological effects characteristic of isolation stress in the test mice, all isolated and control mice were mated after a 6½ month experimental, isolation period. No differences were observed in fertility and fecundity of the two groups of mothers. Analyses of developmental growth rates of the litters of the isolated versus control mothers showed significantly lower body weights in the test offspring at 3 and 4 weeks of age. The body weights of the female offspring remained significantly lower from the 4th to 11th weeks. The effects on the body weights of the male offspring declined and were no longer statistically significant at the 5th to 11 weeks. Locomotor activity at 4½ and 8 weeks of age was markedly or significantly higher in the male and female mice from isolated mothers. Tail-blood samples taken prior to autopsy at 5 and 11 weeks of age revealed significant decreases in the total leukocyte and eosinophil counts of both sexes. At the two ages, the absolute and relative spleen and thymus weights of the male and female offspring were markedly and/or significantly lower than the values observed in counterpart young from control females. Significant decreases were also observed in the absolute gonadal organ weights of both sexes at 11 weeks of age. The various data indicated inhibited growth rates, heightened locomotor activity and evasiveness, as well as evidence of increased adrenocortical function in the offspring from test mothers. The gonadal weight decreases suggested retarded gonadal development. Further studies using split-litter techniques are required to differentiate the effects of prenatal endocrine imbalances versus postnatal maternal influence (i. e., nursing care) on the offspring.


1978 ◽  
Vol 14 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. L. Monteith

SUMMARYFigures for maximum crop growth rates, reviewed by Gifford (1974), suggest that the productivity of C3 and C4 species is almost indistinguishable. However, close inspection of these figures at source and correspondence with several authors revealed a number of errors. When all unreliable figures were discarded, the maximum growth rate for C3 stands fell in the range 34–39 g m−2 d−1 compared with 50–54 g m−2 d−1 for C4 stands. Maximum growth rates averaged over the whole growing season showed a similar difference: 13 g m−2 d−1 for C3 and 22 g m−2 d−1 for C4. These figures correspond to photosynthetic efficiencies of approximately 1·4 and 2·0%.


1997 ◽  
Vol 483 ◽  
Author(s):  
S. A. Ustin ◽  
C. Long ◽  
L. Lauhon ◽  
W. Ho

AbstractCubic SiC films have been grown on Si(001) and Si(111) substrates at temperatures between 600 °C and 900 °C with a single supersonic molecular beam source. Methylsilane (H3SiCH3) was used as the sole precursor with hydrogen and nitrogen as seeding gases. Optical reflectance was used to monitor in situ growth rate and macroscopic roughness. The growth rate of SiC was found to depend strongly on substrate orientation, methylsilane kinetic energy, and growth temperature. Growth rates were 1.5 to 2 times greater on Si(111) than on Si(001). The maximum growth rates achieved were 0.63 μm/hr on Si(111) and 0.375μm/hr on Si(001). Transmission electron diffraction (TED) and x-ray diffraction (XRD) were used for structural characterization. In-plane azimuthal (ø-) scans show that films on Si(001) have the correct 4-fold symmetry and that films on Si(111) have a 6-fold symmetry. The 6-fold symmetry indicates that stacking has occurred in two different sequences and double positioning boundaries have been formed. The minimum rocking curve width for SiC on Si(001) and Si(111) is 1.2°. Fourier Transform Infrared (FTIR) absorption was performed to discern the chemical bonding. Cross Sectional Transmission Electron Microscopy (XTEM) was used to image the SiC/Si interface.


Herpetozoa ◽  
2019 ◽  
Vol 32 ◽  
pp. 39-44 ◽  
Author(s):  
Fabio M. Guarino ◽  
Angelica Crottini ◽  
Marcello Mezzasalma ◽  
Jasmin E. Randrianirina ◽  
Franco Andreone

We characterized the body size (as snout-vent length), age, sexual size dimorphism, and growth rate in a population of one of the larger riparian frog from Madagascar (Mantidactylusgrandidieri) from a rainforest patch close to Vevembe, SE Madagascar. We identified a significant female-biased sexual size dimorphism. Age was estimated using phalangeal skeletochronology and was significantly higher in females than in males. Modal age class turned out to be 4 years in both sexes but a large percentage of adult females (75%) fell in the 5–6 years-old classes, while no male exceeded 4 years. We here report M.grandidieri as a medium-long-lived anuran species. Von Bertalanffy’s model showed similar growth trajectories between the sexes although the growth coefficient in females (k = 0.335) was slightly but not significantly higher than in males (k = 0.329).


2013 ◽  
Vol 10 (8) ◽  
pp. 5267-5280 ◽  
Author(s):  
F. H. Chang ◽  
E. C. Marquis ◽  
C. W. Chang ◽  
G. C. Gong ◽  
C. H. Hsieh

Abstract. Allometric scaling of body size versus growth rate and mortality has been suggested to be a universal macroecological pattern, as described by the metabolic theory of ecology (MTE). However, whether such scaling generally holds in natural assemblages remains debated. Here, we test the hypothesis that the size-specific growth rate and grazing mortality scale with the body size with an exponent of −1/4 after temperature correction, as MTE predicts. To do so, we couple a dilution experiment with the FlowCAM imaging system to obtain size-specific growth rates and grazing mortality of natural microphytoplankton assemblages in the East China Sea. This novel approach allows us to achieve highly resolved size-specific measurements that would be very difficult to obtain in traditional size-fractionated measurements using filters. Our results do not support the MTE prediction. On average, the size-specific growth rates and grazing mortality scale almost isometrically with body size (with scaling exponent ∼0.1). However, this finding contains high uncertainty, as the size-scaling exponent varies substantially among assemblages. The fact that size-scaling exponent varies among assemblages prompts us to further investigate how the variation of size-specific growth rate and grazing mortality can interact to determine the microphytoplankton size structure, described by normalized biomass size spectrum (NBSS), among assemblages. We test whether the variation of microphytoplankton NBSS slopes is determined by (1) differential grazing mortality of small versus large individuals, (2) differential growth rate of small versus large individuals, or (3) combinations of these scenarios. Our results indicate that the ratio of the grazing mortality of the large size category to that of the small size category best explains the variation of NBSS slopes across environments, suggesting that higher grazing mortality of large microphytoplankton may release the small phytoplankton from grazing, which in turn leads to a steeper NBSS slope. This study contributes to understanding the relative importance of bottom-up versus top-down control in shaping microphytoplankton size structure.


Author(s):  
M Wan Zahari ◽  
J K Thompson ◽  
D Scott

The effects of plane of nutrition on the body composition of growing sheep are very apparent when animals are compared at the same age following different nutritional histories. These differences are, however, less obvious when animals of the same breed and sex are compared at the same body weight and at present there is some conjecture whether composition is affected by growth rate. This uncertainty is not limited to fat and protein but includes the bone and ash, fraction and the ash composition.The primary objective of this trial was to study the effects of different growth rates achieved by feeding different amounts of the same concentrate diet on the composition of empty-body gain and on the retention of minerals by growing lambs. A secondary objective was to examine the effect of adding supplementary calcium carbonate to the basal diet at the fast rate of growth.


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