Open-circuit Chambers Research Articles

Effect of feed restriction on the maintenance energy requirement of broiler breeders.

ObjectiveThis study aimed to evaluate the effect of the ad libitum and restricted feeding regimen on fasting heat production (FHP) and body composition.MethodsTwelve Hubbard broilers breeders were selected with the same body weight and submitted in two feeding regimes: Restricted (T1) with feed intake of 150 g/bird/d and ad libitum (T2). The birds were randomly distributed on the treatments in two runs with three replications per treatment (per run). The birds were adapted to the feed regimens for ten days. After that, they were allocated in the open-circuit chambers and kept for three days for adaptation. On the last day, oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured by 30 h under fasting. The respiratory quotient (RQ) was calculated as the VCO2/VO2 ratio, and the heat production (HP) was obtained using the Brower equation (1985). The FHP was estimated throughout the plateau of HP 12 hours after the feed deprivation. The body composition was analyzed by dual-energy X-ray absorptiometry scanning at the end of each period. Data were analyzed for one-way analysis of variance using the Minitab software.ResultsThe daily feed intake was 30 g higher to T2 (p<0.01) than the T1. Also, the birds of the T2 had significatively (p<0.05) more oxygen consumption (+3.1 L/kg0.75/d) and CO2 production (+2.2 L/kg0.75/d). That resulted in a higher FHP 359±14 kJ/kg0.75/d for T2 than T1 296±17.23 kJ/kg0.75/d. In contrast, the RQ was not different between treatments, with an average of 0.77 for the fasting condition. In addition, protein and fat composition were not affected by the treatment, while a tendency (p<0.1) was shown to higher bone mineral content on the T1.ConclusionThe birds under ad libitum feeding had a higher maintenance energy requirement but their body composition was not affected compared to restricted feeding.

Degradation of sulfadiazine and electricity generation from wastewater using Bacillus subtilis EL06 integrated with an open circuit system

Antibiotics are one of the emerging pollutants that have drawn increased attention in recent years. In this study simultaneous production of electricity and bioremediation of sulfadiazine from the wastewater using microbial fuel cells (MFCs) and open circuit system were analyzed. LC-MS analysis revealed decreased sulfadiazine concentration in open circuit system and closed MFC chamber. In MFCs, 12.6 ± 1.3% removal efficiency of sulfadiazine was reached after 30 h and it improved 89.2 ± 2.1% after 100 h. The initial sulfadiazine concentration influenced on antibiotic removal in MFCs and antibiotic removal was increased up to 350 μg/L. At higher antibiotic concentration, reduced microbial activity results depleted antibiotic degradation. MFCs degraded sulfadiazine (350 μg/L) completely within 80 h of treatment. The maximum COD removal (91.9 ± 2.3%) was obtained in MFCs chamber and it was about 60.8 ± 2.7% in the open circuit chamber. The initial total phosphorus content of the wastewater fed with reactor was 1350 mg/L and it reduced considerably after treatment in MFCs system (89.9 ± 2.8%). Total microbial population was 4.5 × 105 CFU/mL after one day of treatment and it declined after five days due to the depletion of nutrients in the wastewater. In MFC electricity generation reached maximum within 60 h of treatment (1.28 ± 0.1 V). The electrogenic strain Bacillus subtilis EL06 was characterized from the MFC and sulfadiazine tolerance was analyzed. These findings demonstrated that MFCs are useful for the simultaneous bioremediation of wastewater and electricity generation.

Methane emissions of geese (Anser anser) and turkeys (Meleagris gallopavo) fed pelleted lucerne

In contrast to mammalian herbivores, birds are generally perceived to produce little methane (CH4) during digestion, and accounting for poultry in greenhouse gas inventories is considered unnecessary. We measured CH4 emissions in six domestic geese (Anser anser, 5.0 ± 0.9 kg) and six domestic turkeys (Meleagris gallopavo, 6.3 ± 0.6 kg) kept on a diet of lucerne pellets only, using open-circuit chamber respirometry. Measurements of oxygen consumption were similar to previously published values in these species. Absolute CH4 emissions per day were lower in geese (0.58 ± 0.10 L) than in turkeys (1.48 ± 0.16 L) and represented 0.4 ± 0.2 and 0.6 ± 0.1% of gross energy intake, respectively. These results confirm previous findings on the presence of methanogenes in the digestive tract of poultry species, and in vitro measurements performed on poultry caecal contents. In relation to mammalian herbivores in terms of absolute CH4 emissions, CH4 yield per dry matter or gross energy intake, or the CH4:CO2 ratio, the lucerne-fed geese and turkeys had comparatively low values. The emission of CH4 in spite of the very short digesta retention times and low fibre digestibility, as measured in the same animals, gives rise to the hypothesis that that in some birds, caecal fermentation and the associated CH4 production may be related to the microbial digestion of uric acid. The hypothesis that CH4 emissions in poultry may depend not only on dietary fibre but also on dietary digestible protein (that is excreted as uric acid in urine and retrogradely transported from the cloaca into the caeca) remains to be tested.

Integrity Assessment of Open-Circuit Respiration Chambers for Ruminant Animal Indirect Calorimetry

Abstract. Open-circuit chambers have been widely applied to gas exchange measurement for indirect calorimetry and greenhouse gas emission. The reliability of these systems is crucial and is commonly evaluated through recovery tests. These tests simulate gas exchanges of animals through the injection or consumption of known quantities of gases, while monitoring the gas flux with the measurement system, and then comparing the difference between the known mass and the measured mass to assess the system integrity. Although the recovery test approach is widely accepted, the method of how to choose recovery tests has rarely been documented, and no single source has been found that summarizes a complete process for evaluating a system and correcting post-evaluation systematic errors. In this study, three recovery methods were applied: (1) the alcohol combustion method (ACM) burns a known amount of pure ethanol to simulate both consumption (O2) and production (CO2); (2) the gravimetric gas injection method (GRAV) directly measures the weight change of a compressed CO2 gas cylinder during the injection process; and (3) the constant gas injection method (CGIM) steadily injects sulfur hexafluoride (SF6) gas into the chamber. An experiment was conducted that included eight repeated trials for each of the three methods in six identical chambers (144 total tests) of the Ruminant Emission Measurement System (REMS) at the Beef Cattle and Sheep Field Laboratory at the University of Illinois in Urbana-Champaign. The recovery percentages of the respiratory quotient for the six ACM chambers varied from 72.58% to 77.76%, indicating that measurement and calculation errors occurred in the system. The CGIM and GRAV methods were used for identifying the errors from ventilation measurement and calculation of exhaust airflow rate. Correction factors were generated from the results and proved effective, as recovery percentages were improved to an acceptable level (100% ±5%) for all chambers. This approach can be applied to other studies and other systems to assist in selecting appropriate integrity tests and applying correction methods. Keywords: Cattle, Emissions, Gas exchange, Metabolism, Recovery method, Tracer gas measurement.

Methane production by two non-ruminant foregut-fermenting herbivores: The collared peccary (Pecari tajacu) and the pygmy hippopotamus (Hexaprotodon liberiensis)

Methane (CH4) production varies between herbivore species, but reasons for this variation remain to be elucidated. Here, we report open-circuit chamber respiration measurements of CH4 production in four specimens each of two non-ruminant mammalian herbivores with a complex forestomach but largely differing in body size, the collared peccary (Pecari tajacu, mean body mass 17kg) and the pygmy hippopotamus (Hexaprotodon liberiensis, 229kg) fed lucerne-based diets. In addition, food intake, digestibility and mean retention times were measured in the same experiments. CH4 production averaged 8 and 72L/d, 18 and 19L/kg dry matter intake, and 4.0 and 4.2% of gross energy intake for the two species, respectively. When compared with previously reported data on CH4 production in other non-ruminant and ruminant foregut-fermenting as well as hindgut-fermenting species, it is evident that neither the question whether a species is a foregut fermenter or not, or whether it ruminates or not, is of the relevance previously suggested to explain variation in CH4 production between species. Rather, differences in CH4 production between species on similar diets appear related to species-specific differences in food intake and digesta retention kinetics.

Determination and prediction of the net energy content of seven feed ingredients fed to growing pigs based on chemical composition

Two experiments were conducted to determine the net energy (NE) content of various feed ingredients (Exp. 1) and to establish prediction equations for NE for these same ingredients (Exp. 2). In Exp. 1, 36 barrows (27.5 ± 0.5 kg) were assigned to six diets (in a completely randomised design) to give six replicates per diet. The diets were a corn-soybean meal basal diet and five experimental diets containing either wheat, wheat bran, corn dried distillers grains with solubles (cDDGS), canola meal or cottonseed meal. The pigs were housed in six open-circuit chambers (six pigs at a time balanced for dietary treatment) for 16 days, the first 7 days were used for an adaptation to the diets, while for the next 5 days pigs were fed ad libitum (2400 kJ/kg BW0.6·day–1), then fed at 1 × metabolisable energy (ME) for maintenance for 3 days, followed by fasting for 24 h. The NE content of wheat, wheat bran, cDDGS, canola meal, and cottonseed meal were 11.44, 7.78, 10.21, 8.38, and 7.32 MJ/kg DM, respectively. Stepwise regression analysis performed between the chemical composition and the energy value of the ingredients, allowed for the NE to be accurately predicted from chemical characteristics. The best fit equation was: NE = 1.46 + (0.63 × gross energy) – (0.37 × acid detergent fibre), with a R2 of 0.94, a residual standard deviation (RSD) of 0.54 MJ/kg, and P &lt; 0.01. In Exp. 2, 36 barrows (34.6 ± 1.5 kg) were randomly allotted to six diets containing various combinations of corn, soybean meal, wheat, wheat bran, cDDGS, canola meal, or cottonseed meal. The chemical composition of each diet was determined and the results were used to establish prediction equations for the NE in the six diets and 16 diets (including six diets from Exp. 1, six diets from Exp. 2 and four diets from our laboratory published data). The best fit equations were as follows: NE = –0.47 + (0.84 × ME) with an R2 of 0.94, a RSD of 0.20 MJ/kg, and P &lt; 0.01; NE = –10.19 + (0.97 × digestible energy) + (0.08 × starch) + (0.05 × acid detergent fibre) with an R2 of 0.84, a RSD of 0.46 MJ/kg, and P &lt; 0.01, respectively. In summary, the NE of the seven ingredients could be better measured by the respiration calorimetry estimated by substitution method. The NE prediction equation determined based on the chemical characteristics of the test ingredients was better than when determined using the chemical characteristics of the diets.

Validation of a short-term methane measurement using portable static chambers to estimate daily methane production in sheep

There is increasing demand for technologies to measure CH4 production (DMP) of ruminant livestock in inventory and mitigation research. Studies of genetic variation among animals in DMP require these emissions to be measured on thousands of animals which cannot be managed using traditional chamber studies. However, short-term emission measures have been reported to correlate well with DMP. Our study was conducted to determine the usefulness of 1 and 2h emission measures using chambers in predicting DMP. In our first experiment, Merino sheep (n=13) were measured for DMP over 22h using open circuit chambers. On two subsequent days, after overnight fasts, sheep were offered feed for 1h before return to the chambers for 2h and their CH4 production determined. DMP estimated from 22h measurements correlated moderately well with 2h emission measures (r2 of 0.42–0.48) and 1h measures (r2 of 0.39–0.43). In our second experiment, portable static chambers were designed for 1 and 2h CH4 emission measurements. The portable static chambers retained 98–99% of an injected tracer gas after 2h showing that gas leakage from the chamber was very low. With a sheep inside a portable static chamber, CO2 concentration reached 2.2×103ppmv after 2h, but sheep showed no discomfort and the partial pressure of O2 in their blood remained above 97% (i.e., safe for animal health). Our third experiment was to validate use of short-term emission measures from portable static chambers as predictors of DMP. Crossbred Dorset and Border Leicester and Merino ewes (n=40, LW 54±10.9kg) were measured for three 22h sessions in open circuit chambers, after which they were measured for 1h in portable static chambers. Open circuit chamber measurements had high repeatability (i.e., 0.88) and, excluding one sheep with inconsistent eating patterns, the correlation (r) between 1h portable static chamber measurements and average emissions in the open circuit chambers was 0.71. We conclude that 1 and 2h measures of CH4 output in portable static chambers are useful for determining genetic differences in CH4 production in groups of ruminants.This article is part of the special issue entitled: Greenhouse Gases in Animal Agriculture – Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors; K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson.

Construction and operation of open-circuit methane chambers for small ruminants

A detailed description of the construction, calibration and operation of 4 open-circuit chambers designed to measure methane emissions from sheep is given. These chambers have accommodated sheep under ad libitum feeding and have been used in short-term experiments and over extended periods of time. A real-time base data acquisition and process control system provided 24 h operation of the methane chambers. The gas volume measurement system consisted of dry test meters and sensors for differential and absolute pressure, temperature and relative humidity. This enabled correction of methane chamber exhaust air volume to standard temperature and pressure. Temperatures and relative humidity during measurements ranged from 21.0 to 23.1°C and 53.8 to 78.9%, respectively. The gas chromatograms were calibrated 3 times a day using commercially available gas standards. Recovery tests were conducted on each chamber by bleeding a methane gas standard into the chamber at a rate similar to methane production by sheep, with 94.4–107.1% of the methane gas recovered. Measurements on 32 sheep gave methane emissions within predicted levels and identified several low methane-producing sheep.

Olive oil feeding up-regulates uncoupling protein genes in rat brown adipose tissue and skeletal muscle

Some nutrients, such as carotenoids, retinoic acid, and certain types of fatty acids, increase thermogenic capacity. The influence of 4 dietary lipid sources (olive oil, sunflower oil, palm oil, and beef tallow) on the content of uncoupling proteins 1, 2, and 3 (UCP1, UCP2, and UCP3) and their messenger RNA (mRNA) expression in several tissues of rats was compared. Wistar rats were randomly divided into 4 groups and fed ad libitum diets containing 40% of energy as fat. UCP1, UCP2, and UCP3 mRNA and protein were assessed by Northern blot and Western blot, respectively. Oxygen consumption in tissues was measured by polarography. Total-body oxygen consumption was assessed in an open-circuit chamber system. Circulating fuels (fatty acids and glucose) and hormones (triiodothyronine, thyroxine, corticosterone, and insulin) were measured. Olive oil feeding induced the highest UCP1, UCP2, and UCP3 mRNA expression in interscapular brown adipose tissue. An analogous effect was observed in gastrocnemius muscle UCP3 mRNA. No significant differences were observed in perirenal white adipose tissue UCP2 mRNA. Changes in mRNAs were not accompanied by close changes in the protein content of UCPs and were not associated with changes in adipose tissue oxygen consumption. Nevertheless, total-body oxygen consumption was higher in rats fed olive oil than in those fed the other 3 diets. No significant differences were found in body and tissue weights or in serum indexes. Olive oil induced an up-regulating effect on UCP mRNA that was probably not mediated by systemic metabolic changes, but rather related to a local effect on interscapular brown adipose tissue and skeletal muscle.

A comparison of systems for measuring methane emissions from sheep

Two experiments were conducted, at ADAS Drayton in the autumn and winter 1996/1997, to compare methane (CH4) emissions from sheep housed either in a polytunnel system or in open-circuit respiration chambers. In each system, the sheep received maintenance levels of either cut grass or high temperature dried grass pellets (HTDG). All experiments in the tunnel were conducted on concrete to avoid any interactions of the CH4 with the soil/plant environment. The results suggested that CH4 production from the open-circuit chambers was greater than from the tunnel system (26·9±0·46 v. 31·7±0·35 l/kg dry matter intake (±S.E.) for open circuit respiration chambers and tunnel, respectively). Recovery tests gave similar results for both systems (95·5–97·9% for tunnels and 89·2–96·7% for chambers), and confirmed that both methods give good quantitative recovery of added CH4, and can therefore be assumed to provide reliable estimates of emissions from animals. There is no technical explanation, therefore, for the different estimates of emissions provided by the two systems. Further studies are required to understand the reasons for the differences and in particular, the possible links between animal behaviour induced by the two systems and CH4 emission rates.

The energy value of short-chain fatty acids infused into the caecum of pigs.

The present work was undertaken to study the energy value of a mixture of acetic, propionic and butyric acids (0.682:0.226:0.092) infused intracaecally in growing pigs. A basal diet low in fibre (42 g NSP/kg DM) was given at below the requirement for maximum weight gain. In six 2-week periods, N and energy balance measurements in eight growing pigs were carried out with and without infusion of short-chain fatty acids (SCFA). Heat production was measured using open-circuit chambers and the concentration of SCFA in faeces was determined. Less than 1% of the infused SCFA was excreted in faeces illustrating the capacity of the hind-gut to absorb and metabolize SCFA. Infusion of SCFA did not affect the digestibility of nutrients and energy. However, N retention increased demonstrating that SCFA are an energy source for protein gain when pigs are fed at below the requirement of energy. Increased CH4 production together with an increased excretion of branched-chain fatty acids in faeces suggested that there was a higher microbial activity in the hind-gut during infusion. The partial utilization of the infused energy in SCFA was 0.821. A small proportion of the infused energy in SCFA was retained in protein (0.099) and a considerable amount was retained as fat (0.722).

THE ENERGY METABOLISM OF INFANTS AND YOUNG CHILDREN DURING POSTPRANDIAL SLEEP

The energy metabolism of healthy infants, from 1 through 37 months of age, was measured with an open circuit chamber within 3½ hours of the time they had been fed and while they slept with little or no motion. Satisfactory results were obtained in 248 tests on 38 boys and 246 tests on 40 girls. A statistical analysis of the results of these determinations included the means, the standard error of the means, and the standard deviations of the means for cal/hr, cal/hr/m2, cal/hr/kg, and cal/hr/cm referred to age, as well as cal/hr referred to weight, height, and surface area, respectively, for boys and girls. Scatter diagrams for cal/hr and cab/hr/ m2 referred to age for boys were given. In order to differentiate normal thyroid activity from abnormal activity in children of this age, it was found that the best methods of reference to use for comparison, i.e., the methods which gave the least dispersion from the mean in healthy infants, were cal/hr/m2 referred to age and cal/hr referred to surface area, while the least desirable methods of reference for such use, i.e., the methods which showed the widest dispersion from the mean, were cal/hr/kg and cal/hr referred to age. Tentative standard values obtained from the mean trend lines were given for cal/hr/m2 for age and cal/hr for surface area. It was found that, from ½ to 3½ hours after feeding, there was no change in the effect of food on the metabolic rate or on the respiratory quotients. No significant changes were found in the respiratory quotients with age. It was concluded that differences between the energy production of boys and girls up to 3 years of age could be attributed to differences between the sexes in body size for age and body weight for height. The mean heat production of children from 18 to 36 months of age was found to be from 3 to 9% lower in tests done during sleep in the postprandial state than in those done during the usual awake fasting conditions.

BASAL METABOLISM OF NORMAL CHILDREN FROM THIRTEEN TO FIFTEEN YEARS OLD, INCLUSIVE

The basal metabolism of normal children from 2 to 12 years old, inclusive, has been the subject of two reports from this laboratory, one by Lewis, Kinsman and Iliff 1 in 1937 and the other by Lewis, Duval and Iliff 2 more recently. Sufficient data have now been obtained to extend this age range through the sixteenth year. The purpose of this paper is to present, as a report of progress, the mean values of these basal metabolism determinations on normal children from 13 to 15 years old, inclusive. EXPERIMENTAL PROCEDURE The experimental procedure has been the same as that described by Lewis, Kinsman and Iliff. 1 The open circuit chamber method of Higgins and Bates, 3 in which gas analysis is carried out by the Carpenter 4 modification of the Haldane apparatus, has been used. The subjects of the basal metabolism determinations have been members of the group of