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Simultaneous measurement of protein and energy metabolism and application to determine lysine requirements in sows
- Author / Creator
- Samuel, Ryan
Simultaneous measurements of energy and protein metabolism can provide valuable information about their interactions. Dietary lysine is limiting in typical feedstuffs fed to swine and, therefore, limits protein synthesis. Current recommendations for dietary amino acid and energy intakes may not be reflective of the requirements for modern, highly productive sows and, therefore, invalidate requirement estimates determined according to the factorial approach. Current feeding recommendations suggest a constant amino acid intake throughout gestation. However, the demands for amino acids changes from maternal tissue accretion in early-gestation to fetal, conceptus, and mammary tissue development in late-gestation. This thesis reports the method development associated with simultaneous measurements of energy and protein metabolism and its application to determine dietary lysine requirements in non-pregnant and pregnant sows using the indicator amino acid oxidation method.
Two indirect calorimetry systems and an experimental feeding regimen were tested and validated for use in studies of amino acid requirements by stable isotope dilution. Protein and energy balance studies were performed in non-pregnant sows fed two distinct levels of energy and protein intake. The systems reacted appropriately to changes in gas concentrations induced by sow respiration. Protein and energy balance studies were also performed in pregnant and lactating sows fed typical diets. Sows appeared more anabolic during mid-gestation and were catabolic by late-gestation and through lactation, where additional energy intake provided by ad libitum feed intake increased milk energy output.
The dietary lysine requirement in non-pregnant sows at maintenance was determined as 49 mg/kg0.75, 30% greater than current recommendations. The dietary lysine requirement was determined to be 10.1 g/d and 16.5 g/d, in early- and late-gestation, respectively. These results suggest that a constant diet formulation for the entirety of gestation is not appropriate.
In conclusion, simultaneous measurements of energy and protein metabolism combining indirect calorimetry and stable isotope techniques may be used to define requirements for dietary amino acids in sows. Basic assumptions of the factorial approach to estimate requirements require further investigation, including the dietary lysine requirement. Application of phase feeding for sows during gestation can more correctly meet the demands for amino acids and energy, improving sow longevity.
- Graduation date
- Spring 2011
- Type of Item
- Doctor of Philosophy
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.