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Deuterium for Estimating Total Body Water and Turnover Rates in Turkeys Exposed to Different Incubation Treatments

Institute of Animal Breeding and Genetics, University of Göttingen, Albrecht-Thaer-Weg 3, 37075 Göttingen, Germany

¹ Corresponding author: ariek{at}gwdg.de

	ABSTRACT

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
Total water intake (TWI) in poultry can be influenced by various factors. Recommendations for water requirements are usually reported on a flock basis without considering individual variation. In the present study, a total of 18 turkeys were used to measure water intake over a 1-wk period starting at 15 wk of age by applying the deuterium dilution technique. Poults originated from eggs exposed to different incubation treatments, with eggs incubated at normal temperature (37.5°C) and eggs subjected to 38.5°C at embryonic d 9 to 12. Experimental birds were kept in flocks of 22 to 30 birds separated by sex and treatment. Feed and water were provided ad libitum. Incubation treatment had no significant effect on any of the parameters investigated (BW, daily gain, water turnover rate, total body water, TWI), whereas sex exerted a significant effect on nearly all traits. Total body water ranged between 60 and 65% of BW, with significantly (P < 0.05) greater values for toms (63.2%) than for hens (60.9%). Males had approximately 30% greater water influxes than females (1,054 ± 198 vs. 742 ± 153 mL/d, mean ± SD). However, the significant influence of sex was eliminated (P = 0.464) when TWI was expressed as grams per kilogram of BW (76 ± 18 vs. 70 ± 12 mL/kg of BW; males vs. females). Water consumed averaged 837 mL in male and 569 mL per day in female birds. The present results suggest that the isotope dilution method offers a viable method to measure individual water intake, which can be used for establishing reference values for water consumption in group-housed turkeys.

Key Words: turkey • total body water • water flux • isotope dilution • incubation temperature

	INTRODUCTION

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Water requirements are modified by different physiological states in poultry such as egg production (e.g., layers), muscle growth in growing birds (e.g., broiler), or changes in body composition with age (Leeson and Summers, 1997). Various factors have been shown to influence water intake in poultry including strain (Bessei et al., 1999), sex (Ziaei et al., 2007), stocking density (Feddes et al., 2002), health and welfare (Manning et al., 2007), ambient temperature (Belay and Teeter, 1993), and feed restriction and resulting behavioral patterns such as polydipsia (Proudman and Opel, 1981). In addition, it is open to question whether manipulation of embryo development at early sensitive stages by modification of the incubation temperature (Decuypere and Michels, 1992) influences total body water (TBW) and water turnover. Recent studies by Maltby et al. (2004) in turkeys and Hammond et al. (2007) in broilers showed that in ovo manipulation of incubation temperature during early embryogenesis resulted in increased muscle growth, which could affect water turnover and TBW.

Values for water intakes and recommendations for water requirement (e.g., NRC, 1994) in poultry are usually reported on a group or flock basis (e.g., Manning et al., 2007) mainly because of the technical difficulties in measuring individual water flux in birds kept in flocks. On the other hand, birds kept singly may differ in their feeding and drinking behavior compared with group-housed poultry because of lack of social facilitation. In this context, the isotope dilution technique (Lifson and McClintock, 1966) could be a suitable method for estimating individual water flux in flocks of poultry. Isotopes used include the nontoxic stable ²H in deuterium oxide (D₂O) and ³H in tritiated water, which is a weak radioactive β emitter with a long half-life (12 yr). The stable and relatively nontoxic deuterium seems to be a better alternative for welfare reasons and because regulations for the use of radioactive substances and their disposal have become very strict.

The dilution space of the isotope is considered to reflect the TBW content, which is determined by the dilution and equilibration of the labeled water with body fluids. The water turnover rate is calculated from the washout of the isotope over a known period. Since the establishment of the method (Lifson and McClintock, 1966), numerous studies have been undertaken to measure the TBW content and water flux in mammals and birds, particularly in wild species, to evaluate energy expenditure by using a second isotope (for review, see Nagy et al., 1999). Only a few studies have been conducted in domesticated poultry. Johnson and Farrell (1988) estimated body composition in layers, and Degen et al. (1991) studied water consumption in domestic ostriches (Struthio camelus).

Recommendations on water supply in turkeys are scarce and are based on information obtained from commercial turkey production companies (NRC, 1994), but the methodology used is not described. Therefore, the aim of the present study was to evaluate the application of the isotope dilution technique to turkeys kept in groups to measure TBW and water flux and to study the possible influence of incubation treatment on water flux.

	MATERIALS AND METHODS

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The research conducted in this study was performed in accordance with the guidelines established by the Institutional Animal Care and Use Committee of the University of Goettingen, Germany.

Birds and Management

The present trial was part of a larger project that investigated the effect of an increased hatching temperature on the development of BUT (Big 6, Aviagen, Tattenhall, UK) turkey hens and toms. Hatching eggs were obtained from a Big 6 parent flock of 42 wk of age. Eggs were incubated in a Petersime incubator (Petersime, Zulte, Belgium) at a constant temperature of 37.5°C and RH of 55%. Half of the eggs were transferred during embryonic d 9 to 12 to an identical incubator equilibrated to a temperature of 38.5°C and a relative humidity of 55% (HIT treatment), whereas the control eggs (NIT treatment) remained in the first incubator. After heat exposure, HIT eggs were retransferred and exposed to the same conditions as NIT eggs. From embryonic d 25 until hatching, the eggs were incubated in the hatching unit of the incubator at 37.5°C and RH of 60%. After hatch, the poults were wing banded and not debeaked.

The total number of turkey poults kept during the present trial was 203 (NIT = 49 toms and 53 hens; HIT = 49 toms and 52 hens). Birds were kept in 8 groups of 22 to 30 birds separated by sex and treatment in floor pens measuring 3.2 x 2.9 m in the same building. Stocking density ranged from 25.0 to 44.8 kg of BW/m² at the time of the present trial. Birds had free access to food and drinking water throughout the trial. Food offered at wk 15 was a commercial turkey feed containing 880 g of DM/kg, 18.0% CP, 4.0% crude fiber, 8.0% crude fat, 0.85% calcium, 0.65% phosphorus, 0.14% sodium, 5.3% ash, 0.38% methionine, and 12.6 MJ of ME/kg (P5, Raiffeisen-Agravis AG, Rosdorf, Germany). Average daily feed intake was recorded on a group basis per pen for the respective trial period at wk 15. The light schedule was 16L:8D (light onset at 0500 h, light offset at 2100 h, with 15 min of dim phase each), with a light intensity of 20 lx.

The present trial was conducted when the birds reached 15 wk of age. Initially, 5 birds from each incubation treatment and sex (20 birds in total) were randomly chosen from the 8 pens (2 to 3 birds/pen) and stayed within their home flock under controlled stable conditions (mean temperature = 21.9°C; humidity = 65.3%). During the course of the trial, however, 2 males from the HIT group died.

Isotope Administration, Blood Sampling, and Isotope Analysis

Birds had no access to feed and water 2 h before isotope injection. Immediately before the isotope administration, a background blood sample was collected in blood tubes containing citrate. Deuterium oxide of 99.90% purity (Euriso-Top GmbH, Saarbrücken, Germany) was injected intramuscularly into the pectoralis superficialis. The amount administered was determined by the BW of each bird recorded by a high-precision scale (model CW3P1-150IG-I, Sartorius AG, Goettingen, Germany) to the nearest of 0.005 kg before injection. The amount administered was 0.480 ± 0.010 g/kg of BW (mean ± SD). The exact amount of isotope applied to each bird was calculated gravimetrically by weighing the syringe to the nearest 0.001 g before and after administration. Blood samples of approximately 3 mL from each bird were then collected 6, 24, 48, 120, and 168 h postinjection from the wing vein (vena axillaris and vena basilica). Body weight was recorded at the beginning and end of the sampling to determine daily growth (wk 15). Blood samples were centrifuged at 1,500 x g for 10 min at ambient temperature, and 1 mL of plasma was stored in glass vials at –20°C until analysis.

Earlier work showed that tracer concentrations in plasma samples are the same as in vacuum-sublimated water samples (Riek et al., 2007). Therefore, plasma samples were analyzed for D₂O concentrations. Analyses were carried out at the Competence Center of Stable Isotopes (KOSI, Goettingen University, Goettingen, Germany). Isotope ratios of ²H were measured using an on-line high temperature reduction technique in a helium carrier gas described previously (Gehre et al., 2004) and expressed relative to the Vienna standard mean ocean water, which is the international reference standard for D₂O. Individual samples were measured in triplicate and the averages calculated.

Calculations

Isotope concentrations in plasma samples were corrected for changes in pool size in each bird due to growth according to the equation

([1])

where C_t* is the resulting corrected isotope concentration at time t after administration (in atom % excess), C_t is the measured isotope concentration at time t (atom % excess), BW_t is the corresponding BW at that time, and BW₀ is the BW at the beginning of the trial. It was assumed that body water comprises a constant proportion of BW during the respective measurement period.

Isotope equilibration and fractional water turnover were computed for each bird by extrapolating the regression of isotope concentrations on time by the regression equation

([2])

where C_t* is the corrected isotope concentration (atom % excess), C₀ is the equilibration concentration (intercept, atom % excess), k is the fractional water turnover (slope), and t is the time elapsed since tracer administration (Holleman et al., 1982). Isotope equilibration and pre-dose baseline concentration was then used to calculate the initial D₂O dilution space, which was considered to reflect the TBW (kg) by using the following formula:

([3])

where D is dose in grams.

Final pool size was calculated by multiplying the ratio of initial pool size to initial BW by the final BW. Total water intake (TWI) per day was calculated according to the formula published by Oftedal et al. (1983):

([4])

where L = amount of daily water lost, G = amount of daily water stored, TBW_avg = body water pool size at the midpoint of the study, k = daily water turnover rate, and TBW = daily change in pool size. Total water intake includes preformed and metabolic water from food and drinking water. Metabolic water was calculated from the feed composition. Following Schmidt-Nielsen (1979), 1 g of metabolized protein, fat, and carbohydrate yields 0.50, 1.07, and 0.56 g of H₂O, respectively. According to the composition of the food, birds ingested 120 g of preformed water per kg of feed intake and 314 g of metabolic water per kg of DM intake.

Water drunk was calculated as

([5])

Statistical Analysis

Statistical analyses were performed with SAS version 9.01 (SAS Institute, 2001). To extrapolate the regression of C_t* on time by Eq. [2], the nonlinear regression procedure (PROC NLIN) was used for estimating C₀ and k for each bird. Analyses of variance were performed using the GLM procedure as follows:

where Y_ijk = observation value; µ = overall mean; S_i = fixed effect of the ith sex (i = male, female); T_j = fixed effect of the jth incubation treatment (j = NIT, HIT); S x T_ij = interaction between the ith sex and jth incubation treatment; and e_ijk = random error.

	RESULTS

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Incubation treatment had no significant effect on any of the parameters investigated, and none of the incubation treatment x sex interactions was significant (Table 1). Sex exerted a significant effect on all parameters, except for k and TWI expressed as milliliters per kilogram of BW. Total body water (in kg and %) was significantly greater in male than in female birds, with low individual variation within the same sex (Table 2). The regression equation of TBW on BW across sexes was log₁₀ TBW = 1.120 BW log₁₀ – 0.338 (n = 18, R² = 0.959, P < 0.001).

As the feed intake per bird was recorded (on a group basis), water ingested by drinking could also be determined by Eq. [5]. Based on these calculations, male birds drank 837 mL and female birds drank 569 mL per day on average (Table 2). Feed intake per day ranged (depending on sex and treatment) from 425 to 560 g per bird, which was equal to 375 to 493 g of DMI. Combining data on water and feed consumption resulted in an average water to feed ratio of 1.46:1 to 1.82:1.

	DISCUSSION

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Incubation temperature had no significant effect on any of the parameters measured in this trial. Therefore, the overall TBW was not modified by incubation treatment. This is in contrast to studies for turkeys (Maltby et al., 2004), where in ovo temperature manipulation influenced posthatch muscle growth.

To the authors’ knowledge, this is the first study investigating TBW, water consumption, and water turnover in turkeys using the isotope dilution technique. Body water expressed as percentage of BW (Table 2) was in the range of reported data for emus (Dromaius novaehollandiae; Dawson et al., 1983), domesticated ostriches (Strurhio camelus; Degen et al., 1991), and layers (Johnson and Farrell, 1988), confirming that the isotope dilution technique gives reliable results for TBW and water turnover in birds (Mata et al., 2006).

Total body water expressed as percentage of BW usually decreases with age because of the accumulation of body lipids, and it ranges in mature birds from 58 to 65% (Johnson and Farrell, 1988; Degen et al., 1991; Mata et al., 2006). Although birds in the present trial were not fully mature, TBW expressed as a percentage of BW ranged between 60 and 65%, suggesting that the relationship between TBW and BW does not change largely at that age in turkeys.

The NRC (1994) values for water consumption in 15-wk-old turkeys kept at an average ambient temperature of 20°C are 6,800 mL/bird per week for males and 4,720 mL/bird per week for females, which translates into 971 and 674 mL/bird per day for males and females, respectively. These values are slightly greater than those obtained in the present study (Table 2). However, the methodology for the establishment of the NRC values was not described. Intake of drinking water was about 76 to 80% of TWI. This is nearly identical to values established for layers (78%; Vogt, 1987) and ostriches (81%; Degen et al., 1991) of comparable ages, suggesting that around 20% of water intake in poultry comes from food and metabolic water.

The present results suggest that the isotope dilution method offers a viable method to measure water intake for establishing reference values for water consumption in group-housed turkeys. The dilution method has the advantage that water flux can be measured individually while animals are kept under commercial conditions in large flocks. In addition, no technical equipment is necessary to consider water evaporation from drinkers or water spillage by the birds, which could reach a considerable amount, particularly in water fowl (Reiter, 1997).

	ACKNOWLEDGMENTS

 
We wish to thank J. Langel (Competence Center for Stable Isotopes, University of Göttingen) for organizing the stable isotope analyses. The technical assistance of J. Dörl and the technical staff of the Institute of Animal Breeding and Genetics of the University of Goettingen are highly appreciated.

Received for publication June 19, 2008. Accepted for publication August 11, 2008.

	REFERENCES

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
Belay, T., and R. G. Teeter. 1993. Broiler water balance and thermobalance during thermoneutral and high ambient-temperature exposure. Poult. Sci. 72:116–124.[Web of Science]

Bessei, W., K. Reiter, and H. Feile. 1999. Zur Variation der Wasseraufnahme in zwei verschiedenen Legehennenlinien. Arch. Geflugelkd. 63:115–121.

Dawson, T. J., R. M. Herd, and E. Skadhauge. 1983. Water turnover and body water distribution during dehydration in a large arid-zone bird, the emu, Dromaius novaehollandiae. J. Comp. Physiol. 153:235–240.

Decuypere, E., and H. Michels. 1992. Incubation temperature as a management tool: A review. World’s Poult. Sci. J. 48:28–38.[CrossRef][Web of Science]

Degen, A. A., M. Kam, A. Rosenstrauch, and I. Plavnik. 1991. Growth rate, total body water volume, dry-matter intake and water consumption of domesticated ostriches (Strurhio camelus). Anim. Prod. 52:225–232.

Feddes, J. J. R., E. J. Emmanuel, and M. J. Zuidhof. 2002. Broiler performance, body weight variance, feed and water intake, and carcass quality at different stocking densities. Poult. Sci. 81:774–779.[Abstract/Free Full Text]

Gehre, M., H. Geilmann, J. Richter, R. A. Werner, and W. A. Brand. 2004. Continuous flow ²H/¹H and ¹⁸O/¹⁶O analysis of water samples with dual inlet precision. Rapid Commun. Mass Spectrom. 18:2650–2660.[CrossRef][Medline]

Hammond, C. L., B. H. Simbi, and N. C. Stickland. 2007. In ovo temperature manipulation influences embryonic motility and growth of limb tissues in the chick (Gallus gallus). J. Exp. Biol. 210:2667–2675.[Abstract/Free Full Text]

Holleman, D. F., R. G. White, and J. R. Luick. 1982. Application of the isotopic water method for measuring total body water, body composition and body water turnover. Pages 9–32 in Use of Tritiated Water in Studies of Production and Adaptation in Ruminants. Int. At. Energy Agency, Nairobi, Kenya.

Johnson, R. J., and D. J. Farrell. 1988. The prediction of body-composition in poultry by estimation in vivo of total body water with tritiated-water and deuterium oxide. Br. J. Nutr. 59:109–124.[Medline]

Leeson, S., and J. D. Summers. 1997. Commercial Poultry Nutrition. 2nd ed. Univ. Books, Guelph, Ontario, Canada.

Lifson, N., and R. McClintock. 1966. Theory of use of the turnover rates of body water for measuring energy and material balance. J. Theor. Biol. 12:46–74.[CrossRef][Web of Science][Medline]

Maltby, V., A. Somaiya, N. A. French, and N. C. Stickland. 2004. In ovo temperature manipulation influences post-hatch muscle growth in the turkey. Br. Poult. Sci. 45:491–498.[CrossRef][Web of Science][Medline]

Manning, L., S. A. Chadd, and R. N. Baines. 2007. Water consumption in broiler chicken: A welfare indicator. World’s Poult. Sci. J. 63:63–71.

Mata, A. J., M. Caloin, J.-P. Robin, and Y. Le Maho. 2006. Reliability in estimates of body composition of birds: Oxygen-18 versus deuterium dilution. Physiol. Biochem. Zool. 79:202–209.[CrossRef][Web of Science][Medline]

Nagy, K. A., I. A. Girard, and T. K. Brown. 1999. Energetics of free-ranging mammals, reptiles, and birds. Annu. Rev. Nutr. 19:247–277.[CrossRef][Web of Science][Medline]

NRC. 1994. Nutrient Requirements of Poultry. 9th rev. ed. Natl. Acad. Press, Washington, DC.

Oftedal, O. T., H. F. Hintz, and H. F. Schryver. 1983. Lactation in the horse: Milk composition and intake by foals. J. Nutr. 113:2096–2106.[Abstract/Free Full Text]

Proudman, J. A., and H. Opel. 1981. Effect of feed or water restriction on basal and TRH-stimulated growth hormone secretion in the growing turkey poult. Poult. Sci. 60:659–667.[Medline]

Reiter, K. 1997. Das Verhalten von Enten (Anas platyrhynchos f domestica). Arch. Geflugelkd. 61:149–161.

SAS Institute. 2001. SAS Software. Release 9.01. SAS Inst. Inc., Cary, NC.

Riek, A., M. Gerken, and E. Moors. 2007. Measurement of milk intake in suckling llamas (Lama glama) using deuterium oxide dilution. J. Dairy Sci. 90:867–875.[Abstract/Free Full Text]

Schmidt-Nielsen, K. 1979. Animal Physiology: Adaptation and Environment. 2nd ed. Cambridge Univ. Press, Cambridge, UK.

Vogt, H. 1987. Fütterung des Geflügels. Pages 216–311 in Geflügel. S. Scholtyssek ed. Ulmer, Stuttgart, Germany.

Ziaei, N., J. H. Guy, S. A. Edwards, P. J. Blanchard, J. Ward, and D. Feuerstein. 2007. Effect of gender on factors affecting excreta dry matter content of broiler chickens. J. Appl. Poult. Res. 16:226–233.[Abstract/Free Full Text]

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