PSIV-25 Development of an indirect calorimetry system to determine heat production in individual lactating sows

Abstract

Abstract Determining total heat production (THP) in individual sows and litters can be difficult and often requires the use of multiple animals to generate data on a per room basis. These systems may be costly to construct precluding their use by many researchers. The study objective was to develop a low cost indirect calorimetry system to determine THP in individual lactating sows and litters. Six indirect calorimeters were constructed to house 1 sow and litter in a crate throughout farrowing and a 21-d lactation period. Chamber accuracies for O2 and CO2 were evaluated by ethanol combustion. One-week pre-farrowing, 6 pregnant multiparous sows (parity 2.9 ± 0.9; 218.3 ± 38.6 kg BW) were housed individually in each farrowing crate and maintained in thermoneutral conditions (20.9 ± 2.6°C and 43.7 ± 18.6% relative humidity) throughout lactation. On lactation d 4, 8, 14, and 18, indirect calorimetry was performed on all sows and their litters, as well as 2 piglets from a sentinel litter to determine THP. Sentinel piglet data were used to estimate THP for the sows independent of the litter. Sow + litter THP (kcal/h) increased (P = 0.01; 16.6%) on d 8 compared to d 4 and was greater (27.3%) on d 14 and d 18 compared to d 4 and d 8. Sow THP was greater (P = 0.01) on d 8 (401.19 ± 17.15 kcal/h) and d 14 (430.79 ± 12.42 kcal/h) compared to d 4 (346.16 ± 16.62 kcal/h), and was greater on d 14 compared to d 8 and on d 18 (386.16 ± 20.02 kcal/h) compared to d 14. In summary, this cost-effective system can allow researchers to accurately evaluate THP in individual lactating sows and their litters