caa a22 4500 386322511 CHVBK 20180307111631.0 cr unu---uuuuu 161130e198809 xx s 000 0 eng 10.1079/BJN19880107 doi S0007114588001084 pii (NATIONALLICENCE)cambridge-10.1079/BJN19880107 Dove H. CSIRO, Division of Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia Estimation of the intake of milk by lambs, from the turnover of deuterium- or tritium-labelled water [Elektronische Daten] [H. Dove] 1. The total water turnovers of grazing ewes and their lambs were estimated on days 9, 23, 44, 69 and 86 of lactation from the dilution of tritiated water injected into the dam and deuterium oxide injected into the offspring. The contribution of milk to the total water turnover of the lambs was estimated at the same times from the accumulation of tritium in their body water. 2. Mean total water turnover in the ewes was 6.5 litres/d over the entire period. In lambs, total turnover rose from 1459 ml/d at 9 d to 2791 ml/d at 86 d, and was closely related to live weight (r2 0.760, P < 0.001). The corrections to total water turnover, which were required because of the increasing body water pool size of the lambs during each measurement period, fell from +10.6% at 9 d to +3.7% at 86 d. All corrections were significant (P < 0.001). 3. The intake of water as milk fell throughout the study, from 1501 ml/d at 9 d to 471 ml/d at 86 d. Pool-size corrections were significant (P < 0.001). Milk intakes calculated from these results were 1816, 1054, 862, 742 and 588 ml/d at 9, 23, 44, 69 and 86 d of lactation. The rapid decline in milk intake reflected undernutrition of the ewes in early lactation. 4. The level of live-weight gain in early lactation was closely related to, and at a level expected from, the estimated milk intakes. From comparisons of estimated milk intakes with published estimates, it is concluded that the combined use of deuterium oxide and tritiated water results in accurate estimates of milk intake by the lamb throughout the ewe's lactation. Copyright © The Nutrition Society 1988 British Journal of Nutrition Cambridge University Press 60/2(1988-09), 375-387 0007-1145 60:2<375 1988 60 BJN https://doi.org/10.1079/BJN19880107 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1079/BJN19880107 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Dove H. CSIRO, Division of Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia NATIONALLICENCE 773 0- British Journal of Nutrition Cambridge University Press 60/2(1988-09), 375-387 0007-1145 60:2<375 1988 60 BJN CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge