Determination of net energy content of dietary lipids fed to growing pigs using indirect calorimetry1

Abstract

The objective of this experiment was to determine the NE content of different dietary lipids fed to growing pigs using indirect calorimetry. Thirty-six growing (initial BW: 41.1 ± 3.1 kg) barrows were allotted to 6 diets based on completely randomized design with 6 replicate pigs per diet. Diets included a corn-soybean meal basal diet and 5 test diets each containing 10% palm oil, poultry fat, fish oil, corn oil, or flaxseed oil at the expense of corn and soybean meal. During each period, pigs were individually housed in metabolism crates for 14 d, which included 7 d for adaptation to feed, metabolism crates, and environmental conditions. On day 8, pigs were transferred to the open-circuit respiration chambers and fed 1 of the 6 diets at 2.3 MJ ME/kg BW0.6/day. Total feces and urine were collected and daily heat production (HP) was also calculated from day 9 to day 13. On the last day of each period (day 14), pigs were fasted and the fasting heat production (FHP) was measured. The results show that the FHP of pigs averaged 809 kJ/kg BW0.6·day-1 and was not affected by diet characteristics. The DE values were 35.98, 36.84, 37.11, 38.95, and 38.38 MJ/kg DM, the ME values were 35.79, 36.56, 36.92, 37.73, and 38.11 MJ/kg DM, and the NE values were 32.42, 33.21, 33.77, 34.00, and 34.12 MJ/kg DM, for the palm oil, poultry fat, fish oil, corn oil, and flaxseed oil, respectively. Based on our result, we concluded that the DE content of dietary lipid varied from 91% to 98% of its GE content, the ME content of dietary lipid was approximately 99% of its DE content, and the NE content of dietary lipid was approximately 90% of its ME content in growing pigs.

Integrative Analysis of Energy Partition Patterns and Plasma Metabolomics Profiles of Modern Growing Pigs Raised at Different Ambient Temperatures

“…Six open-circuit respiration chambers (1.4 m × 2.7 m × 2.1 m) located in the FengNing Swine Research Unit of China Agricultural University (Academician Workstation in Chengdejiuyun Agricultural and Livestock Co., Ltd., Chengde, China) were used to conduct the indirect calorimetry, which was described in details in previous studies [12,13] except for temperature settings. The relative humidity was controlled at 70-75% (EE10-M1A6D1 Moisture/Temperature Measuring Transducer, E+E Elektronik, Austria), and the air velocity was controlled at 0.1 m/s(Gas Mass Flow Meters, Alicat Scientific Inc., Tucson, AZ, USA).…”

“…The FHP was calculated using the same equation, but the 24-h FHP was predicted from the 8 h HP after feed deprivation from 22:00 to 06:00 during the last day of each period, which was then extrapolated to the 24-h period [13]. The RE was calculated as the difference between ME i and THP, while the RE as protein (RE P ) was calculated as N retention (g/d) × 6.25 × 23.86 (kJ/g), and the RE as lipid (RE L ) was calculated as the difference between RE and RE P [13]. The net energy (NE) intake was calculated as the sum of RE and maintenance energy estimated by FHP [17].…”

Energy partition patterns and plasma metabolomics profiles of modern growing pigs under different ambient temperatures: modelling and integrative analysis

“…Six open-circuit respiration chambers (1.4 × 2.7 × 2.1 m 3 ) located in the FengNing Swine Research Unit of China Agricultural University (Academician Workstation in Chengdejiuyun Agricultural & Livestock Co., Ltd) were used to conduct the indirect calorimetry, which were described in details in previous studies [12,13] with the exception of temperature settings. The relative humidity was controlled at 70-75%, and the air velocity was controlled at 0.1 m/s.…”

“…For fecal samples, the contents of DM and CP were determined. For urine samples, the nitrogen (N) content was measured according to Li et al [13].…”

“…The FHP was calculated using the same equation, but the 24-h FHP was predicted from the 8-h HP after feed deprivation from 22:00 to 06:00 during the last day of each period, which was then extrapolated to the 24-h period [13]. The RE was calculated as the difference between ME i and THP, while the RE as protein (RE P ) was calculated as N retention (g/d) × 6.25 × 23.86 (kJ/g), and the RE as lipid (PE L ) was calculated as the difference between RE and RE P .…”