Estimation of body water and fat in cattle using tritiated water space and live weight with particular reference to the influence of breed

1983 ◽  
Vol 101 (2) ◽  
pp. 257-264 ◽  
Author(s):  
P. R. N. Chigaru ◽  
D. H. Holness

SUMMARYThe body composition of 18 each of Mashona, Afrikaner and Hereford heifers was measured at the beginning and after 16 and 32 weeks of the experiment. The heifers not slaughtered at the beginning of the experiment were fed a complete diet containing 132 g crude protein and 12·0 MJ metabolizable energy/kg dry matter. Before slaughter, the animals were deprived of food and water for 24 h. Each animal was infused with 1 mCi of tritiated water (TOH) in order to measure total body water (TBW) and to estimate body fat.The growth rate of the three breeds of heifers was similar despite differences in age and initial live weight. Both TBW and fat proportions, however, differed significantly (P < 0·01) between slaughter stages for each breed and between breeds at each slaughter stage. At the first, second and final slaughter stages the proportions of TBW were: 68·0, 59·4 and 54·5% for Mashona; 70·;5, 64·3 and 58·3% for Afrikaner and 65·3, 57·6 and 46·2% for Hereford heifers respectively. The corresponding proportions of body fat were: 10·2, 18·4 and 24·2% for Mashona; 6·6, 12·0 and 20·0% for Afrikaner and 13·7, 20·8 and 25·8% for Hereford heifers respectively.There was a close relation between empty body weight and live weight at slaughter which was not influenced by breed. Both TBW and fat were estimated more accurately when TOH space and live weight were used jointly. However, the slopes of the prediction equations for each breed were significantly different (P < 0·05) in the case of both total body water and fat. It was necessary to use separate equations for each breed in order to predict either body water or fat. The significance of these findings for the estimation of body fat in live cattle is discussed.

1988 ◽  
Vol 47 (3) ◽  
pp. 435-445 ◽  
Author(s):  
F. R. Dunshea ◽  
A. W. Bell ◽  
K. D. Chandler ◽  
T. E. Trigg

ABSTRACTA two-pool model of tritiated water kinetics was investigated as a means of partitioning total body water into empty body water and gut water in 17 lactating goats. Empty body water, gut water and total body water were of a similar magnitude to, and highly correlated with, a rapidly equilibrating tritiated water pool, a more slowly equilibrating pool and the sum of these two pools, respectively.Empty body fat was poorly correlated with both live weight and empty body weight (R2 = 0·42 and 0·51, respectively). However, there was a strong inverse relationship between the water and fat contents of the empty body. Consequently, empty body fat was accurately predicted by a multiple regression equation which included both empty body weight and empty body water as independent variables (R2 = 0·97). Substitution of these variables with estimates derived from tritiated water kinetics still resulted in a high correlation (R2 = 0·88). Tritiated water kinetics offered little improvement over live weight alone in the prediction of empty body protein, empty body ash or fat-free empty body.


1979 ◽  
Vol 29 (1) ◽  
pp. 81-90 ◽  
Author(s):  
R. T. Cowan ◽  
J. J. Robinson ◽  
J. F. D. Greenhalgh ◽  
I. McHattie

ABSTRACTChanges in body composition during lactation were measured in 12 Border Leicester × Scottish Blackface ewes by serial slaughter at 12, 41 and 111 days of lactation. Ewes suckled twin lambs and were given daily 1·6 kg dry matter of a complete diet containing 151 g crude protein and 10·2 MJ metabolizable energy/kg dry matter.Live weights of ewes averaged 60·2, 58·9 and 55·8 kg at 12, 41 and 111 days of lactation respectively. There were no significant changes in weights of stomach, small and large intestine and liver.The weight of body fat averaged 9·19, 2·28 and 1·19 kg at 12, 41 and 111 days respectively (P < 0·001) and weight of ash increased from 1·72 kg at 12 days to 2·30 kg at 111 days (P < 0·001). Water to protein ratios at the three stages of lactation were 2·94, 3·36 and 3·18 (P < 0·10). The energy value of weight loss varied from 68 to 17 MJ/kg, depending on the relative changes in total body water and fat. Live-weight change was therefore a poor indicator of change in body energy during early lactation.Body fat could be predicted from its combined relationships with live weight and total body water (residual s.d. ±0·70 kg), but when deuterium oxide space was used to estimate body water separate equations were necessary for early and later stages of lactation. This was apparently due to differences between stages of lactation in the time required for deuterium oxide to equilibrate with water in the reticulo-rumen.


1979 ◽  
Vol 92 (1) ◽  
pp. 69-81 ◽  
Author(s):  
J. Z. Foot ◽  
E. Skedd ◽  
D. N. McFarlane

SummaryIn two experiments with female Scottish Blackface or Border Leicester x Scottish Blackface sheep nine or ten animals were slaughtered in mid lactation and the remainder either in November at the time of the subsequent mating (Expt 1) or at weaning (Expt 2).The sheep were infused periodically, including just before slaughter, with 100 μCi tritiated water (TOH) in order to measure total body water by dilution and to estimate body fat using the inverse relationship between the proportions of fat and water in the body. The accuracy of the methods was assessed when the sheep were slaughtered. In the ton lactating Scottish Blackface sheep of Expt 1 fat made up 11.5% of the total body weight with an S.D. of 8·38% whereas the 11 sheep slaughtered at mating were twice as fat (23·2, S.D. 4·01 %). The 25 Border Leicester × Blackface sheep were all thin, whether they were slaughtered in mid lactation (4·4, S.D. 2·56%) or at weaning (3·4, S.D. 2·81%).The standard error of estimate of body water from TOH space in Expt 2 was 1·2 kg c.v. 2·8%) and lower in Expt 1.The precision with which an animal could be weighed was very important in determining the accuracy with which body fat could be predicted from live weight and TOH space. In both experiments the standard error of estimate for body fat in lactating sheep was between 600 and 700 g, compared with 1·3–2·7 kg when body fat was predicted from live weight alone. These estimates were sufficiently accurate to be of value in following changes in body composition in live animals as their nutritional and physiological state alters and for comparing animals in groups where the average fatness is greater and the range wider than in the sheep used in Expt 2.


1988 ◽  
Vol 59 (1) ◽  
pp. 109-124 ◽  
Author(s):  
R. J. Johnson ◽  
D. J. Farrell

1. Birds (n169) which varied in age, live weight, nutritional history, physiological state and genotype were slaughtered and analysed for total body water. Before slaughter, birds were injected with the water isotopes tritiated water (TOH) or deuterium oxide (D2O), or both, to determine TOH space or D2O space, or both, as estimates of total body water in vivo.2. At the mean total body water of all birds determined by desiccation, of 1096·4 (SD 424·1) g, TOH space and D2O space overestimated total body water by 10·4 and 8·5 % respectively. The difference between the isotopes was significant (P< 0·05).3. Based on recovery of isotope it was postulated that the main reason for the observed overestimation of total body water in vivo was incomplete recovery of isotope due to the vacuum sublimation technique. The mean recovery (%) of added isotope to whole blood after vacuum sublimation was 93·0 (SD 2·6) and 92·4 (SD 5·5) of the theoretical concentrations of TOH and D2O respectively.4. Nevertheless, accurate prediction of total body water was obtained from regression equations which included live weight and isotope-dilution space. Values required logarithmic (base 10) transformation before derivation of linear and multiple linear regression equations, and the precision of prediction was determined by the residual standard deviation (RSD).5. Total body water could be predicted with nearly equal accuracy from live weight or isotope-dilution space (RSD 0·025 and 0·020 respectively). Prediction of carcass protein was more accurate from live weight (RSD 0·033) than from TOH space (RSD 0·036), and inclusion of both variables resulted in only a marginal decrease in RSD to 0·031.6. The prediction of carcass fat and energy was markedly improved by the inclusion of isotope-dilution space in conjunction with live weight compared with live weight alone.7. The relations show the developmental nature of body composition of domestic fowl given diets adequate in nutrients. The prediction equations demonstrate the precision possible for studies in which estimates of body composition in poultry are required without slaughter.


1979 ◽  
Vol 42 (2) ◽  
pp. 173-183 ◽  
Author(s):  
J. S. Garrow ◽  
Susan Stalley ◽  
R. Diethelm ◽  
Ph. Pittet ◽  
R. Hesp ◽  
...  

1. A new apparatus is described with which it is possible to measure the volume (and hence density) of obese patients without requiring them to immerse totally in water. Replicate measurements of subjects with 6, 23 and 38 kg body fat had a standard deviation not greater than 0.3 kg fat.2. In nineteen obese women body fat was measured by density, total body water, and total body potassium at the beginning, and again at the end, of a period of 3–4 weeks on a reducing diet, during which they lost 5.43 (SD 1.83) kg in weight. The composition of weight loss was also estimated both by energy balance and nitrogen balance during the interval between the two measurements of body composition.3. The estimates of fat content of the nineteen women at the start of the balance period were 45.63 (SD 14.50)kg by density, 48.07 (SD 13.88) kg by K and 47.09 (SD 13.85) kg by water. The correlation coefficient between the density and K estimate was 0–949, and for the density and water estimate it was 0.971.4. It is concluded that measurement of density by the new method provides a convenient method for estimating body fatness, and change in fat content, which compares favourably with estimates based on total body water or total body K. However, these methods cannot be used to provide an accurate estimate of the composition of a small weight loss in an individual since deviations up to 4 kg fat occur between fat loss based on change in density and those based on the more reliable (but more tedious) energy balance method.


2001 ◽  
Vol 2001 ◽  
pp. 206-206 ◽  
Author(s):  
R. E. Agnew ◽  
W J McCaughey ◽  
J.D. McEvoy ◽  
D C Patterson ◽  
M G Porter ◽  
...  

San Pietro and Rittenberg (1953) reported that urea appeared to meet all the requirements of a satisfactory tracer. Urea is non toxic, not foreign to the body and it shows an even and rapid distribution throughout the total body water without any physiological effect. For these reasons in addition to its easy and accurate measurement, urea is an ideal candidate tracer to estimate empty body water in vivo. Total body water volume (urea space) can be estimated by dividing the total amount of urea infused by the increase in plasma urea concentration from prior to infusion until 12 or 30 minutes after mean infusion time. Kock and Preston (1973) reported significant relationships between urea space measurements and percentage of empty body fat and water in cattle. However, Andrew et al. (1995) using 21 Holstein cows showed that prediction of empty body water using the urea space technique only explained 31 % of the variation. The objective of this experiment was to use the urea dilution technique to estimate the body composition of lactating dairy cows and produce relationships between urea space and body fat and protein content.


1974 ◽  
Vol 82 (1) ◽  
pp. 105-112 ◽  
Author(s):  
B. S. W. Smith ◽  
A. R. Sykes

SUMMARYEight mature female sheep were offered a ration which maintained body weight constant during a 20-week period. During the final 10 weeks a comparison was made in each animal of the pattern of equilibration and urinary losses of tritiated water during 8 h after dosing by four different routes. These were intravenous, intraperitoneal, intraruminal and a combination of the intraperitoneal and intraruminal routes. Tritiated water spaces were calculated from (a) the 8-h plasma specific activity and (b) by extrapolation to zero time of the plasma specific activities during the 7 days after injection. At the end of the experiment the fat and water contents of the bodies of the sheep were determined directly.Complete equilibration of tritiated water between plasma and rumen water was not achieved in all animals 8 h after intravenous or intraperitoneal injection but was when the rumen was primed by the combination of intraperitoneal and intraruminal dosing. After intraruminal dosing equilibration was not achieved in any animal within 8 h of dosing.Urinary losses of marker were lower after intraruminal dosing but otherwise averaged 4–5 % of the dose/1 urine. This was equivalent to 0·3–6·7% of the dose for individual sheep.Errors resulting from incomplete equilibration and urinary loss of marker did not influence the efficiency of prediction of total body water from tritiated water space. The multiple correlation coefficient relating body fat with empty body weight and its water content was very high (r = 0·99). Errors introduced into this relationship by the inclusion of gut water in the prediction equations were apparently of a similar magnitude to those resulting from the errors in the estimation of tritiated water space.The extrapolation method for the determination of tritiated water space was shown to have the same accuracy as equilibration techniques under these controlled dietary conditions.


1968 ◽  
Vol 19 (2) ◽  
pp. 267 ◽  
Author(s):  
BA Panaretto

Correlations are described between tritiated water space, total body water, fat, and protein in sheep subjected to 18–21 hr of fasting. These provide a system for estimating the body composition of living ruminants.


1980 ◽  
Vol 95 (3) ◽  
pp. 515-522 ◽  
Author(s):  
R. T. Cowan ◽  
J. J. Robinson ◽  
I. McHattie ◽  
C. Fraser

SUMMARYThe efficacy of estimates of gut contents and total body water in increasing the precision with which the chemical composition of the body could be estimated in early lactation was evaluated in 36 Finnish Landrace × Dorset Horn ewes. The ewes were fed at two levels in pregnancy, and, in lactation, given diets of two metabolizable energy concentrations.The allometric relationships relating weight of chemical fat and protein to emptybody weight were not affected by treatment or stage of lactation. Inclusion of an index of gut contents, based on dry-matter intake, indigestibility and retention time of food residues, together with live weight in a regression equation predicting weight of body fat, only slightly increased the precision of estimate compared with equations using live weight alone.There was a close negative relationship between the proportions of water and fat in live weight. Inclusion of weight of body water with live weight in a regression equation predicting weight of body fat markedly increased the precision of estimate and the residual error (0·81 kg) was similar at different stages of lactation. However, when deuterium oxide space was used instead of body water there was only a small increase in precision of estimate and the residual error varied from 5·3 kg in early lactation to 2·1 kg in mid-lactation. The relationship between deuterium oxide space and body water was shown to be variable and altered by stage of lactation, and these differences were associated with differences in rate of water turnover in the animal's body.It is concluded that estimates of body water are unsuitable for estimating weight of body fat in early lactation.


1999 ◽  
Vol 1999 ◽  
pp. 50-50
Author(s):  
S. De Campeneere ◽  
L.O. Fiems ◽  
J.M. Vanacker ◽  
B.G. Cottyn ◽  
Ch.V. Boucqué

Urea is non-toxic, not foreign to the body and it shows an even and rapid distribution throughout the total body water without any physiological effect or toxic manifestation. For these reasons and for its easy and accurate measurement, urea is an ideal tracer to estimate body composition in vivo. Total body water volume (urea space) can be estimated by dividing the total amount of urea infused by the increase in plasma urea concentration between prior to infusion and 12, 18 or 24 min after mean infusion time (Preston and Kock, 1973). In this experiment the urea infusion technique was evaluated to estimate body composition of Belgian Blue double-muscled bulls.


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