The Permeability to Water of the Cuticle of the Larva of Opifex Fuscus (Hutton) (Diptera, Culicidae)

1974 ◽  
Vol 60 (3) ◽  
pp. 593-603
Author(s):  
SUSAN W. NICOLSON ◽  
JOHN P. LEADER
Keyword(s):  
Body Weight ◽  
Permeability Coefficient ◽  
Sea Water ◽  
Deuterium Oxide ◽  
Tritiated Water ◽  
The Body ◽  
A Value ◽  
Diffusional Permeability ◽  
Freshwater Insects ◽  
Cuticular Surface

1. Fourth-instar larvae of Opifex fuscus were found to have a mean body weight of 7.61 mg, a water content of 85.2%, and a mean cuticular surface area of 29.3 mm2. 2. Larvae ligatured at neck and anus were found to lose 1 % of the body weight per hour when immersed in sea water. 3. The osmotic permeability coefficient of the cuticle was calculated from these data to be 2.4x10-2 cm. h-1. 4. Measurement of the diffusional permeability coefficient (Pd) by means of tritiated water and Deuterium oxide gave a value for this parameter of 4.8x10-3 cm.h-1. 5. The diffusional permeability of the cuticle of Opifex fuscus is thus less than that of typical freshwater insects, as predicted by Shaw & Stobbart.

Sodium Regulation and Adaptation to Fresh Water in Gammarid Crustaceans

1968 ◽  
Vol 48 (2) ◽  
pp. 359-380
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Body Weight ◽  
Fresh Water ◽  
Body Surface ◽  
Sea Water ◽  
Sodium Concentration ◽  
The Body ◽  
Outward Diffusion ◽  
Gammarus Zaddachi ◽  
Freshwater Habitats ◽  
Sodium Regulation

1. Sodium uptake and loss rates are given for three gammarids acclimatized to media ranging from fresh water to undiluted sea water. 2. In Gammarus zaddachi and G. tigrinus the sodium transporting system at the body surface is half-saturated at an external concentration of about 1 mM/l. and fully saturated at about 10 mM/l. sodium. In Marinogammarus finmarchicus the respective concentrations are six to ten times higher. 3. M. finmarchicus is more permeable to water and salts than G. zaddachi and G. tigrinus. Estimated urine flow rates were equivalent to 6.5% body weight/hr./ osmole gradient at 10°C. in M. finmarchicus and 2.8% body weight/hr./osmole gradient in G. zaddachi. The permeability of the body surface to outward diffusion of sodium was four times higher in M. finmarchicus, but sodium losses across the body surface represent at least 50% of the total losses in both M. finmarchicus and G. zaddachi. 4. Calculations suggest that G. zaddachi produces urine slightly hypotonic to the blood when acclimatized to the range 20% down to 2% sea water. In fresh water the urine sodium concentration is reduced to a very low level. 5. The process of adaptation to fresh water in gammarid crustaceans is illustrated with reference to a series of species from marine, brackish and freshwater habitats.

Growth in sheep. I. The chemical composition of the body

1972 ◽  
Vol 79 (3) ◽  
pp. 371-382 ◽  
Author(s):  
T. W. Searle ◽  
N. McC. Graham ◽  
M. O'Callaghan
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Energy Content ◽  
Phase 1 ◽  
Tritiated Water ◽  
The Body ◽  
Average Weight ◽  
Protein Energy ◽  
Rumen Development ◽  
Set Up

SUMMARYFifteen sheep were fed ad libitum from 2 days to 27 months of age, and another 15 sheep were each fed exactly half the average amount consumed by the first group, age for age. The body composition of each sheep (water, fat, protein, energy) was estimated from tritiated water space on 13 occasions during this period.To describe the course of growth in individual sheep in terms of the relationships between the various body components and body weight, a model was set up in which 4 phases of growth were distinguished, viz. the milk-feeding phase, the period of rumen development, and a prefattening followed by a fattening ruminant phase. Each phase was represented by a linear equation.Except for phase 1, mean composition within each phase differed significantly between well-fed animals and those which had been given a restricted diet. Individual animals differed in the body weight at which the final phase commenced; the average weight was ca. 31 kg. Fat storage was zero or negative during the main period of rumen development; otherwise the fat and therefore energy content of weight gain increased from phase to phase. The protein and water content of gain was high in phases 1 and 2 and decreased subsequently.Calculations based on data in the literature indicated that, in phase 4, the composition of weight loss was the same as that of weight gain. It is also suggested that the body weight at which this fattening phase commences is related to mature weight, with animals of large ultimate size starting to fatten at heavier body weights than those of small ultimate size.The application of the results to the determination of nutrient requirements is discussed.

The Physiology of the Antennal Gland of Carcinus Maenas (L.)

1969 ◽  
Vol 51 (1) ◽  
pp. 11-16
Author(s):  
R. BINNS
Keyword(s):  
Body Weight ◽  
Sea Water ◽  
Carcinus Maenas ◽  
Urine Flow ◽  
The Body ◽  
Antennal Gland ◽  
Urine Production ◽  
The Mean ◽  
Gland Function ◽  
Water Clearance

1. The space measured by inulin distribution, the ‘inulin volume’, has been determined, and represents approximately 20% of the body weight in crabs ranging in size from 20.0 to 57.2 g. 2. After the injection of labelled inulin into crabs, the increase in activity of the medium is equal to the fall in blood inulin in all dilutions of sea water. Clearance of inulin from the blood is due only to urine production, and therefore the molecule can be used for quantitative investigations of antennal gland function. 3. Urine production in various concentrations of sea water has been determined by measuring the clearance of inulin from the blood and the rates at which the tracer appeared in the external media. By these methods the mean rate of urine production in 100% sea water was estimated to be 4.4% body weight per day. In dilute sea water the rate of urine production increases; for example, in 50% sea water the urine flow is four times greater than in normal sea water.

The effect of dehydration on Sudanese desert sheep and goats

1986 ◽  
Vol 106 (1) ◽  
pp. 17-20 ◽  
Author(s):  
H. M. El-Hadi
Keyword(s):  
Body Weight ◽  
Body Temperature ◽  
Extracellular Space ◽  
Total Body Water ◽  
Tritiated Water ◽  
The Body ◽  
Water Turnover ◽  
Sheep And Goats ◽  
Fluid Compartments ◽  
Total Body

SUMMARYChanges in body weight and body temperature were observed in Sudanese desert sheep and goats, which had been subjected to the summer sun (20 °C min. to 42 °C max.), given water normally and then deprived of water for 3 days. Tritiated water was also used to measure total body water and water turnover in these animals together with measurements of plasma and extracellular space, intracellular fluid volume and blood osmolality. The body weight and the size of the fluid compartments decreased in the two species at varying degrees associated with haemoconcentration. The extent of some changes was more marked in sheep than in goats, suggesting better adaptation of the former species to desert life.

The composition of body-weight changes in underfed lactating beef cows

1981 ◽  
Vol 32 (1) ◽  
pp. 95-103 ◽  
Author(s):  
P. R. N. Chigaru ◽  
J. H. Topps
Keyword(s):  
Body Weight ◽  
Milk Production ◽  
Milk Yield ◽  
Deuterium Oxide ◽  
Tritiated Water ◽  
Body Weight Loss ◽  
Beef Cows ◽  
Weight Changes ◽  
Weight Losses ◽  
Unit Body Weight

ABSTRACTThe effects of reducing the feed intake of 12 winter-calving (Hereford male × British Friesian female) cows to the maintenance level for 6 weeks from week 10 of lactation were investigated during two consecutive lactation periods. Initially, six cows were in their first and six in their third lactation. In each year the period of ‘underfeeding’ was preceded by a period of ‘adequate feeding’ (maintenance plus milk production requirements) and succeeded by a period of ‘refeeding’ (2 × maintenance). Changes in body water, estimated by the dilution of tritiated water and deuterium oxide at the end of each feeding period, were used to calculate changes in body tissue. Milk yield during the period of ‘adequate feeding’ indicated that individual cows differed markedly in milk production potential. During ‘underfeeding’ milk yield was related to lactation potential. Cows of higher potential tended to maintain higher yields than those of lower potential but in doing so they incurred higher body-weight losses. The ‘refeeding’ period did not result in significant increases in milk yield. The weight losses during ‘underfeeding’ consisted mainly of fat but some cows apparently mobilized relatively large amounts of protein. More fat per unit body weight loss was mobilized by the heifers than by the cows, which, on the other hand appeared to mobilize relatively more protein. On ‘refeeding’, only a few cows were able to achieve complete tissue repletion.

scholarly journals Rate of endogenous methionine oxidation in rats at different levels of methionine intake

1983 ◽  
Vol 50 (1) ◽  
pp. 157-162 ◽  
Author(s):  
R. J. Neale ◽  
J. C. Waterlow
Keyword(s):  
Body Weight ◽  
Single Dose ◽  
Total Radioactivity ◽  
The Body ◽  
Female Rats ◽  
Methionine Oxidation ◽  
A Value ◽  
Intake Level ◽  
Different Levels ◽  
Fractional Loss

1. The fractional rates of loss of 14C and body-weight were measured in growing female rats after a single dose of [1-14C]methionine. After the dose, the rats were maintained for 30 d on diets containing graded amounts of methionine and killed at 30 d.2. By 20 d after the dose the level of labelling of body proteins was fairly uniform. From 20 to 30 d, 14CO2 was collected at intervals. The rats were killed at 30 d and the total radioactivity remaining in the body was measured.3. The fractional loss of 14CO2 between days 20 and 30 was constant regardless of methionine intake except at the highest intake level.4. After correcting the fractional loss of 14CO2 for urinary 14C loss, a value of 35 mg/kg body-weight (20 mg/kg body-weight0·75) was obtained for the rate of endogenous methionine oxidation.

The body composition of growing sheep during milk feeding, and the effect on composition of weaning at various body weights

1976 ◽  
Vol 86 (3) ◽  
pp. 483-493 ◽  
Author(s):  
T. W. Searle ◽  
D. A. Griffiths
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Tritiated Water ◽  
Body Weight Loss ◽  
The Body ◽  
Whole Body ◽  
Protein Energy ◽  
Body Weights ◽  
Similar Body ◽  
Milk Feeding

SummaryThirty-four (13♂, 21♀) entire cross-bred lambs were suckled on reconstituted, spray-dried cows' milk from 2 days of age for varying periods of time up to 18 weeks before being weaned on to solid food or slaughtered to determine chemical composition. The body composition of each sheep (water, fat, protein, energy) was also estimated from the tritiated water (TOH) space at 3-weekly intervals during milk feeding, at intervals of 5–8 weeks subsequently and at slaughter. Comparison between. TOH estimates and whole body analysis confirmed the accuracy of the previously-derived prediction equations.The relationship between each of the various body components and body weight for individual sheep during milk feeding was described by a ‘bent’ (non-rectangular) hyperbola. There were no substantial differences between animals in either the position or slope of the lower asymptote nor in the slope of the upper asymptote. There were, however, substantial differences in the point of intersection of the two asymptotes both within and between sexes. The mean intersection points for males and females were 17·7 and 14·4 kg body weight respectively.Sheep weaned at body weights of 11–16 kg subsequently followed the previously defined pattern of growth. Weaning at higher body weights (21–34 kg, body fat not less than 5·5 kg) resulted initially in both fat and/or body weight loss. In the final fattening phase of growth early- and late-weaned sheep of the same sex had similar body composition but females were fatter than males.

Prediction of body compostion of sheep from tritiated water space and body weight—tests of published equations

1970 ◽  
Vol 75 (3) ◽  
pp. 497-500 ◽  
Author(s):  
T. W. Searle
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Tritiated Water ◽  
Infected Sheep ◽  
The Body ◽  
Regression Equations ◽  
General Application ◽  
Body Weights ◽  
Healthy Sheep ◽  
Water Space

SUMMARYThe body composition of parasite-infected sheep and of healthy sheep of various body weights and breeding was predicted from tritiated water (TOH) space and body weight using previously published regression equations. Results agreed well with body composition determined by analysis of the minced carcass though a small bias existed in some groups. It is concluded that the equations have a general application to the prediction of body composition in sheep.

Body weight and wool production in grazing sheep given access to a supplement of urea and molasses: intake of supplement/response relationships

1975 ◽  
Vol 84 (1) ◽  
pp. 39-48 ◽  
Author(s):  
J. V. Nolan ◽  
B. W. Norton ◽  
R. M. Murray ◽  
F. M. Ball ◽  
F. B. Roseby ◽  
...  
Keyword(s):  
Body Weight ◽  
Weight Change ◽  
Tritiated Water ◽  
Parasite Burden ◽  
Poor Quality ◽  
The Body ◽  
Body Weight Change ◽  
Once Daily ◽  
Faecal Egg Count ◽  
The Relationship

SUMMARYA technique for estimating the intake of liquid supplements by individual, grazing animals was used in a trial with 200 sheep grazing poor quality pasture and given access to a urea-molasses supplement (19%, w/v).A mathematical procedure was developed to estimate intake of supplement based on measurements of the accumulation of tritiated water (TOH) and its rate of turnover in the body of each animal after a TOH-labelled mixture had been available for a period of 7 days.In calculating the level of intake of labelled supplement, it was assumed that each animal ingested the mixture once daily over the 7-day period, since animals were observed to take the supplement daily and the daily loss of supplement from the dispenser was noarly constant. It was estimated that the combined intakes of the animals accounted for 87% of the known total loss of labelled supplement from the dispenser.Of the 200 sheep, 97 did not consume any supplement and among the other 103 animals, estimated intake varied from 5 to 550 ml/day.All sheep lost body weight during the trial, but those consuming the supplement lost significantly less weight, and grew significantly more wool during the period of supplementation, than did the sheep that did not consume the supplement.A small but significant amount of the variance (13%) in body-weight change and wool growth during supplementation was removed by multiple regression analysis, by including the intake of the supplement, faecal egg count (as an indication of parasite burden) and body weight at the start of the trial, as independent variables. Other factors not studied (e.g., dry matter intake) apparently accounted for a large proportion of the variance.The relationship between body-weight change and intake of the urea-molasses mixture was compatible with the hypothesis that the supplement was used largely as a concentrate feed, and not solely as a nitrogen supplement.

Studies of weaner sheep during and after a period of weight stasis. II.* Body composition

1975 ◽  
Vol 26 (2) ◽  
pp. 355 ◽  
Author(s):  
TW Searle ◽  
NMcC Graham
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Tritiated Water ◽  
Complete Recovery ◽  
The Body ◽  
Similar Weight ◽  
The Mean ◽  
The Relationship ◽  
Weight For Age

Wether sheep (4 months old) were held at 20 kg liveweight by restricted feeding for either 4 or 6 months and then fed ad libitum. Body composition (total water, fat and protein) was estimated monthly from tritiated water (TOH) space measured in vivo, and on three occasions representative animals were slaughtered, minced and analysed. Composition at any given body weight was compared with that previously determined for animals grown without restriction (controls). Sheep slaughtered at the end of the period of weight stasis contained less protein and more water than the controls but contained a similar weight of fat. Previously derived prediction equations estimated water correctly from TOH space in these undernourished sheep, but protein was overestimated by 0.38 kg (17% of the mean) and fat was underestimated by 0.19 kg (10% of the mean). The body composition of animals slaughtered after partial or complete recovery of weight for age was normal for their weight and predictions were accurate. The sequential estimates of composition indicated that although the relationship between fat and weight differed between individuals, at any given body weight above 32 kg compensating animals and controls had a similar composition. *Part I, Aust. J. Agric. Res., 26: 343 (1975).

Sign in / Sign up

Export Citation Format

Share Document