Growth of vibrissae in the marsupial Trichosurus vulpecula

1974 ◽  
Vol 22 (2) ◽  
pp. 117 ◽  
Author(s):  
AG Lyne ◽  
AM Downes ◽  
HB Chase

The autoradiographic technique was used to study the growth of the vibrissae in the mystacial, genal, and supraorbital regions of three brush-tailed possums. During the first cycle there were well-marked gradients in length within and between the rows of mystacial vibrissae. The length growth rates of the corresponding vibrissae on the left and right sides of the body were almost identical at any particular time, although the growth rates varied throughout the cycle. The variations in the final lengths of the vibrissae were due to variations in both the growth rate and the length of the cycle. The diameters increased continuously throughout the cycle. The rate of regrowth after plucking vibrissae from active and resting follicles was also studied. The new vibrissa in a particular follicle initially grew at a much faster rate than either the corres- ponding undisturbed vibrissa on the other side of the head or the vibrissa which had just been plucked. The subsequent rate of growth decreased progressively throughout the cycle. In spite of differences in growth rates during the first and later cycles, the overall dimensions of the successive vibrissae from a particular follicle were very similar. The normal retention of vibrissae was studied in one animal. At least some vibrissae were retained for more than a year after they had stopped growing. The results demonstrate that the vibrissae of T. vulgecula provide an excellent model for studies of the factors controlling follicle activity.

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.


1993 ◽  
Vol 41 (2) ◽  
pp. 141 ◽  
Author(s):  
RT Gemmell ◽  
JK Hendrikz

Although the bandicoot Isoodon macrourus and the brushtail possum Trichosurus vulpecula give birth to similar-size young, about 200 mg, the pouch young of the bandicoot grow more quickly than those of the possum. The bandicoot is weaned at 59 days when the body weight is between 90 and 250 g. A young possum weighs about 20 g at Day 60 and between 780 and 1031 g when weaned at Day 170-180 post partum. The body weight of both species has been described previously as a continuous curve expressed by a quadratic equation. In this study, instead of assuming the growth curve to be continuous, the growth curve has been expressed as two components. The growth rates of both species were similar from birth until Day 12 post partum; the bandicoot then had a faster growth rate. The results from iterative analysis indicated a change in growth rate at Day 30 (data for Days 31 and 32 were missing) and Day 96 post partum for the bandicoot and possum, respectively. Thus, both marsupials showed a change in growth rate as hair appeared, eyes opened and the young first left the pouch.


2011 ◽  
Vol 9 (3) ◽  
Author(s):  
Muhammad Mansur

Ecological studies on the Nepenthes species at Barito Ulu, Central Kalimantan, Indonesia were conducted between August 2005 and September 2006. Surveys and two small plot inventories were used to determine the diversity and population of Nepenthes at the study site. We found eight Nepenthes species around the BaritoUlu study area: N. albomarginata, N. ampullaria, N. gracilis, N. hirsuta, N. rafflesiana, N. reinwardtiana, N. stenophylla, and N. hispida. Plot A was dominated by N. rafflesiana with one other species found; whilst in plot B we found five species but it was also dominated by N. rafflesiana. In plot A, the one year stem length growth rate of N. albomarginata was faster than N. rafflesiana (5.0 and 3.5 cm respectively). While in plot B, N. gracilis (21.7 cm) and N. reinwardtiana (13.1 cm) showed faster growth rates than N. albomarginata (5.2 cm), N. rafflesiana (7.0 cm) and N. stenophylla (8.5 cm). Generally, the habitat of Nepenthes in the study site is heath forest.


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.


1967 ◽  
Vol 15 (1) ◽  
pp. 95 ◽  
Author(s):  
RF Parsons ◽  
RL Specht

In southern Australia, deep calcareous and deep siliceous sands each carry a distinctive assemblage of eucalypts. Three of these species with contrasting edaphic ranges were investigated: Eucalyptus baxteri, which is widespread on acidic soils and is never found on highly alkaline soils like the calcareous sands; E. incrassata, which is widespread on acidic and neutral soils, occurs occasionally on some highly alkaline soils, but is also absent from calcareous beach sands; and E. diversifolia, which is found on both acidic and highly alkaline soils and is widespread on calcareous beach sands. All three species occur on siliceous sands, with E. baxteri in wetter areas than the other two species. Comparative pot experiments in which typical calcareous and siliceous sands were used showed that: (1) E. baxteri is stunted by severe lime chlorosis when grown on calcareous sand, while the other two species are not affected. (2) E. baxteri markedly outyields the other two species on siliceous sands. It is suggested that E. baxteri is absent from calcareous sands because it is physiologically intolerant of highly alkaline soils, and that E. baxteri replaces the other two species on the wetter siliceous sands because its faster growth rate enables it to outcompete them when rainfall is adequate. However, the slower growth rates of E. diversifolia and E. incrassata will be accompanied by slower rates of water use and this may give them an advantage over E. baxteri on drier siliceous sands. The wide edaphic range of E. diversifolia is considered to be the outcome of the wide physiological tolerance of individual plants rather than of intraspecific differentiation.


2005 ◽  
Vol 72 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Alfonso Zecconi ◽  
Enrica Binda ◽  
Vitaliano Borromeo ◽  
Renata Piccinini

Staphylococcus aureus isolates produce several pathogenic factors. The combination of these products influences the pathogenic role of different isolates, but their specific effects are well known in the pathogenesis of udder infections. This study focused on the association of polymorphism of the coagulase gene, protein A gene, collagen-binding protein gene, and of fibrinogen-binding protein gene on somatic cell count (SCC) and on Staph. aureus growth rate. Fifty Staph. aureus isolates from 13 dairy cow herds, located in seven different provinces, were considered. The results showed a low frequency of cna gene, similar to the one observed in human isolates. Meanwhile, the high frequency of efb gene indirectly confirmed the role of this factor in bacterial pathogenesis, being associated with adhesion to epithelia. The association of these two single genes with SCC and growth rate showed to be not significant. The polymorphism of spa gene was confirmed to be significantly associated with inflammatory response and growth rate, albeit with a pattern different from the one suggested for human isolates. Sorting of isolates based on the clusters obtained by combining polymorphisms of spa and coa genes and the presence of cna and efb genes, showed that a single cluster (cluster V) was prevalent in the different herds and provinces, while the other six clusters identified were widely spread among the remaining 60% of the isolates. Results showed that clusters VI and VII had significantly higher growth rates at 3, 4, and 6 h in comparison with the other clusters. Meanwhile, quarters infected with these strains showed significantly lower SCC levels. The frequency of isolates from cluster V, suggested that they should possess pathogenic factors increasing their invasiveness, even if in the presence of a stronger inflammatory response. These results indirectly confirm previous findings on the different interactions between isolates and the udder immune system. They also suggest that isolates with higher growth rates and inducing a lower inflammatory response have better chances to spread among the herd. The relatively simple genomic method proposed in this study could be applied by an increasing number of diagnostic laboratories and could be useful in studying the epidemiology of Staph. aureus intramammary infections in dairy herds when collecting data from the field.


1983 ◽  
Vol 23 (122) ◽  
pp. 228 ◽  
Author(s):  
MPB Deland ◽  
RW Ponzoni ◽  
RW McNeil

Hereford, Charolais and Brahman sires were mated to Hereford, Shorthorn, Jersey and Friesian xshorthorn cows for four successive years from June 1969 at Struan Research Centre in South Australia. Assistance was given during 15 .9% of calvings resulting from Charolais sires, 6.8% resulting from Brahman sires and 2.1% from Hereford sires (differences statistically significant, P < 0 05). A greater percentage of Friesian x Shorthorn (13.8) than of Shorthorn (5.0) or Jersey (4 3) cows were assisted at birth (P< 0.05). There were no significant differences between the percentage of Hereford cows assisted (10.9) and that of any of the other dam breeds. There were no significant differences in calf mortality among sire breeds or among dam breeds. Charolais-sired calves were heavier at birth, 270,340 and 430 d old and had heavier (1 95 kg) carcasses with a smaller proportion of fat than Brahman- and Hereford-sired carcasses (180 and 167 kg respectively) at 430d old. Brahman-sired calves were heavier than Hereford-sired calves at birth, 370, 430 d old. However, they were significantly lighter at 270 d old. Hereford cows gave birth to significantly heavier calves than Shorthorn and Jersey cows but there were no clear differences due to dam breed in growth rates of calves, carcass weights or composition. It was concluded that the use of Charolais sires in the lower South East of South Australia can result in significant increases in the growth rate of slaughter cattle and in the production of leaner carcasses. Brahman sires did not exhibit clear advantages over Hereford sires. No definite conclusions could be drawn about the dam breeds examined in the study.


1971 ◽  
Vol 48 (4) ◽  
pp. 815-827 ◽  
Author(s):  
D. A. Saville

The interactions between electrical tractions at the interface of a liquid jet and instability phenomena are studied with emphasis on effects due to interfacial charge relaxation. Charge relaxation causes the oscillatory growth of a perturbation. When viscous effects are small, small fields tend to decrease the growth rate of the axisymmetric mode, up to a point, and precipitate instability of the non-axisymmetric modes. Still larger field strengths increase the growth rates of asymmetric as well as axisymmetric modes. Instabilities characterized by highfrequency oscillations appear to persist even though the charge relaxation phenomena may be quite rapid. When, on the other hand, viscous effects predominate the only unstable disturbance form is the axisymmetric one, although the manner of growth may be oscillatory.


2002 ◽  
Vol 139 (2) ◽  
pp. 169-181 ◽  
Author(s):  
L. E. R. DAWSON ◽  
A. F. CARSON

A study was carried out on five lowland farms in Northern Ireland over 3 years to investigate the effect of crossbred ewe and ram genotype on ewe prolificacy, lamb viability and weaned lamb output. Four crossbred ewe genotypes were sourced from six hill farms involved in a previous study – Bluefaced Leicester×Blackface (BLXB), Texel×Blackface (TXB), Suffolk×Cheviot (SXCH) and Texel×Cheviot (TXCH). On each farm, groups of 20–30 of each crossbred ewe genotype were mated with Suffolk or Texel rams. Throughout the 3 years of the study, the ewe genotypes lambed at 1, 2 and 3 years of age. Within each of the ram breeds, high lean growth index rams sourced from UK sire reference schemes were compared with rams sourced from flocks not involved in objective genetic improvement programmes (control). BLXB ewes were the most prolific of the four ewe genotypes producing 1.73 lambs per ewe lambed compared with 1.47 for TXB, 1.46 for SXCH and 1.41 for TXCH (P<0.001). Lamb mortality was similar for the four ewe genotypes, thus number of lambs weaned was greatest for the BLXB ewes (P<0.001) with the other three crosses producing similar numbers of lambs. A greater proportion (P<0.05) of SXCH ewes lambed without assistance compared with BLXB and TXB ewes and a greater proportion of TXCH ewes had abundant supplies of colostrum compared with the other crosses (P<0.10). Output of weaned lamb per ewe lambed and per ewe metabolic live weight (P<0.001) was greatest in the BLXB ewes. Ewe productivity, prolificacy, number of lambs weaned and the proportion of ewes lambing without assistance increased with ewe age (P<0.001). Lamb growth rate from birth to 6 weeks and from birth to weaning increased with ewe age (P<0.05). Crossbred ewes lambing at 3 years old had a greater output of weaned lamb compared with ewes lambing at 1 and 2 years old (P<0.001). Ram genotype had no effect on ewe prolificacy, lamb viability or pre-weaning growth rates, although Texel-sired lambs had lower birth weights than Suffolk-sired lambs and control-sired lambs had lower birth weights than high lean index-sired lambs (P<0.05).


2000 ◽  
Vol 34 (2) ◽  
pp. 202-206 ◽  
Author(s):  
C. Jacobson

As a routine postoperative treatment, a single dose of buprenorphine was given to rats at a dose of 0.05 mg/kg subcutaneously. However, some rats developed abnormal secretions around the nose and mouth and some animals died 3-5 days after surgery and analgesic treatment. At autopsy a yellow fibrous mass was found in the stomach and intestines. Observations of animals given buprenorphine revealed an abnormal ingestion of bedding material. This caused a disturbance to normal digestion, with gastric distension, weight loss or decreased growth rate, constipation and occasionally death. In this study rats were monitored for 6 days following surgery and analgesic treatment. A comparison of growth rates was made between rats given saline and buprenorphine or na1buphine and between animals kept on bedding or grid floors for the first 24 h after treatment. Of the animals held on bedding, the buprenorphine-treated animals did not lose weight as the other animals did, but had on the other hand a decreased growth rate during the measuring period of 6 days after surgery. When denied access to bedding for the first 24 h after surgery, rats given saline or na1buphine had a reduced weight gain over the first 24 h, similar to the groups held on bedding. Rats held on grid floors and given buprenorphine continued to gain weight for the first 24h. From day 3, there was no significant difference between the groups, which all gained weight.


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