Immunological responses and disease resistance of rainbow trout (Oncorhynchus mykiss) juveniles following dietary administration of stinging nettle (Urtica dioica).

摘要: The present study investigated the effects of dietary supplementation stinging nettle (Urtica dioica) on growth performance, skin mucus, immune response and disease resistance rainbow trout (Oncorhynchus mykiss) fed with diets supplemented U. dioica at 0, 1, 2 3%. After 8 weeks feeding, addition 3% level resulted in improved weight gain, specific rate feed conversion ratio significantly when compared to other groups (P < 0.05). Hematological responses including: hematocrit (Htc), hemoglobin (Hb), lymphocyte neutrophil populations enhanced fish measured after 4 weeks; while, total red blood cells, white blood, Htc, Hb, increased same group Total serum protein glucose contents however, triglycerides decreased 4th 8th week Additionally, several parameters, namely, IgM, lysozyme, complement components C3 C4, respiratory burst leukocytes week; At end feeding trial, mucus samples obtained from exhibited antagonistic activities against bacterial pathogens (Streptococcus iniae, Yersinia ruckeri, Vibrio anguillarum Lactococcus garviae), enzymes (alkaline phosphatase, protease esterase) levels highest being case cumulative mortality subjected Y. ruckeri infectious relatively low all lowest nettle. findings demonstrated that administration stimulated immunity; thus, enabling be more resistant infections.