Effects of Hatchery Rearing Density, Handling, and Nutrition on Renibacterium salmoninarum Infection Prevalence in Juvenile Chinook Salmon

• Published in: Journal of aquatic animal health 2020-09, Vol.32 (3), p.116-126
• Main Authors: Larson, Douglas L., Faisal, Mohamed, Tempelman, Robert J., Yu, Hao, Scribner, Kim T.
• Format: Article
• Language: English
• Subjects: Animal Nutritional Physiological Phenomena; Animals; Aquaculture - methods; Fish Diseases - epidemiology; Fish Diseases - microbiology; Gram-Positive Bacterial Infections - epidemiology; Gram-Positive Bacterial Infections - microbiology; Gram-Positive Bacterial Infections - veterinary; Michigan; Population Density; Prevalence; Renibacterium - physiology; Salmon - physiology
• ISSN: 0899-7659; 1548-8667
• DOI: 10.1002/aah.10103

Bacterial kidney disease, caused by Renibacterium salmoninarum (RS), is a chronic and often fatal disease of salmonid species, and can be particularly harmful to hatchery‐reared Chinook Salmon Oncorhynchus tshawytscha. A considerable amount of research has focused on the prevention of vertical and horizontal transmission; however, a comparatively little amount has investigated factors that increase the prevalence of RS infection in captive environments. We evaluated the effects of three common hatchery conditions (handling, nutrition level, and rearing density) on RS infection prevalence. Fish were sampled at 30‐d and 60‐d postexposure to RS. Of 577 juveniles examined, 65 (11.27%) had anterior kidneys infected with RS. Using a logistic mixed model analysis, we found effects of nutrition level (P = 0.018), handling (P = 0.010), and sampling period (P = 0.003) on the prevalence of RS. The interactions of nutrition and handling (P = 0.008) and nutrition and time (P