摘要：Oil-adjuvanted vaccines reduce long-term growth in farmed Atlantic salmon Salmo salar , possibly via an increase in metabolic rate due to the energetic demands of the immune system. We tested this hypothesis by comparing sham-vaccinated to vaccinated smolts (total n = 2096, ca. 80 g) under different scenarios of water temperature (12 vs. 17°C, n = 1048 per temperature) and oxygen (O 2 ) saturation (60, 70, 80, and 100%, n = 524 per O 2 saturation level) in order to manipulate metabolic rate and O 2 availability. We expected a more severe vaccination effect under conditions of high water temperature and low O 2 saturation. Groups were kept in duplicate tanks under controlled temperature and hypoxia conditions for 7 wk post-vaccination before being transferred to uncontrolled common-garden natural conditions for 5 mo in a sea-cage. Body mass and length were recorded at the initiation and end of the controlled and uncontrolled environmental conditions. Vaccination and low O 2 saturation at 17°C significantly reduced body mass (13 and 3% through vaccination and 9 and 20% through 60% O 2 saturation at the end of the tank and sea-cage periods, respectively). However, there was no interaction between vaccination, temperature, and O 2 saturation at the end of the tank or sea-cage period, lending no support to our hypothesis. A secondary observation was that emaciated ‘loser’ fish were mainly associated with the 17°C and low (mainly 60%) O 2 saturation treatment. In conclusion, although vaccination led to a reduction in body mass, this effect was not influenced by environmental conditions expected to alter metabolic rate.
