Respiration chamber

By far, the most suitable method to quantify individual ruminant animal CH4 measurement is by using respiration chamber, or calorimetry. The respiration chamber models include whole animal chambers, head boxes, or ventilated hoods and face masks. These methods have been effectively used to collect information pertaining to CH4 emissions in livestock. The predominant use of calorimeters has been in energy balance experiments where CH4 has been estimated as a part of the procedures followed. Although there are various designs available, open-circuit calorimeter has been the one widely used. There are various designs of calorimeters, but the most common one is the open-circuit calorimeter, in which outside air is circulated around the animal s head, mouth, and nose and expired air is collected for further analysis. 

Measurement of biofilm activity can be performed based on laboratory reactor experiments or with a technique combining biofilm growth taking place in a sewer followed by measurements in laboratory scale (Raunkjaer et al., 1997 Bjerre et al., 1998). Huisman et al. (1999) developed a sewer in situ biofilm respiration chamber. It includes a DO sensor and a chamber that can be pressed onto the sewer wall. It is designed to achieve an even and unidirectional flow distribution over the entire measurement area. Pure oxygen is injected for oxygenation. 

Christensen H, Krogh M, Nielsen M. 1937. Acute mercury poisoning in a respiration chamber. Nature 139 1026-1027. 

The quantity of energy lost in the form of gas (Egas) was calculated using the quantity of fermented cell v/alls. This was considered to be equal to the DRes value obtained in the nutrient digestibility method. The compilation of data obtained in respiration chambers (Le Goff, 2001) allows the estimation of Egas 0.67 and 1.34 kj per g of DRes in the growing pig and the adult sow, respectively. 

The heat production of animals can be measured physically using a procedure known as direct calorimetry. Alternatively, heat production can be estimated from the respiratory exchange of the animal. For this, a respiration chamber is normally used and the approach is one of indirect calorimetry. Respiration chambers can also be used to estimate energy retention rather than heat production, by a procedure known as the carbon and nitrogen balance technique. 

BOX 11.4 Measurement of respiratory exchange using respiration chambers... 

Methane production by ruminants is usually measured using a respiration chamber. However, indirect methods such as the sulphur hexafluoride (SFe) technique may also be used. 

The heat lost by animals may be measured directly in an enclosed chamber called an animal calorimeter. Alternatively, it may be estimated from the animal s respiratory exchange (oxygen consumption and carbon dioxide production) in a respiration chamber. 

Energy retention may be estimated indirectly as ME intake minus heat production, or directly from the animal s carbon and nitrogen retention in a respiration chamber. It may also be measured using the comparative slaughter technique, where a known amount of ME is given and body composition is measured at the beginning and end of the experiment. 

The energy retention of the sheep used in Question 1 was measured by placing it in a respiration chamber. Whilst in the chamber, the sheep consumed 536 1 oxygen and excreted 429 1 of carbon dioxide, 45.8 1 of methane and 19.0 g of urinary nitrogen. Using the Brouwer equation, calculate its heat production and energy retention. 

A pig in a respiration chamber stored 182.5 g carbon and 10.4 g nitrogen each day. Calculate its protein and fat deposition and the energy content of tissue gain. 

After adaptation to each diet, sows were individually housed in respiration chambers for the measurement of indicator amino acid oxidation during a primed, constant infusion of L-[1- C] pheiylalanine and, simultaneously, heat production (HP) over 4 h. The gas exchange was recorded for Oj, COj, and CH,j (Brouwer, 1%5) in 1 min intervals. Expired CO2 and blood plasma were collected in 30 min intervals for determination of enrichment. 

Gas exchange was measured in an open-air-circuit respiration unit (Micro-Oxymax calorimeter from Columbus Instruments, Columbus, Ohio, USA) equipped with four respiration chambers at days 10, 13, 16 and 19 of incubation. Measurements were made on four eggs at a time. They were candled prior to measurement to check the presence of embryo and then set into each respiration chamber for 3 hours from 9 00 to 12 00 followed by another group measured from 13 00 to 16 00. 

The experiment was performed with four randomly selected Holstein Friesian dairy cows being in the state of mid-gestation with an initial body mass of 568 34 kg and an initial milk yield of 19.2 1.2 1/d (mean SD) (Table 1). Animals were halter-trained and adapted to handling and the respiration chambers. They were fed a total mixed ration (TMR) which consisted of, on a DM basis, 70%... 

CSIRO, 2007), those of CNCPS are from the eomparative slaughter trials on beef cattle of Lofgreen and Garrett (1968), whereas those of NRC and INRA are from the energy balances carried out in respiration chambers on laetating dairy eattle by Moe et al. (1972) and van Es (1978), respectively. 

Measurements carried out in groups of broilers weighing on average 1.4 kg the indirect calorimetry method in respiration chambers was used AHP Activity heat production complementary details by Noblet et at. (2007) for trial 1 and Noblet et al. (2009) for trial 2 trial 3 unpublished data, hr trials 1 and 2, the variation in CP or EE content was created by replacement for starch in trial 3, the increased NDF level resulted from dilution by dietary fibre provided by wheat bran, maize bran and soybean hulls, hr trial 1, data have been adjusted for a similar ME intake while observed values are given fortrials 2 and 3. None of the differences between treatments within each trial were significant (P>0.05). 

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