Published in Scientific Papers. Series D. Animal Science, Vol. LXIII, Issue 1
Written by Mirela CREȚU, Raluca Cristina ANDREI (GURIENCU), Lorena DEDIU, Angelica DOCAN, Mihaela MOCANU
Study of the physiological and haematological characteristics of cultured fish represents an important tool in monitoring environmental quality, physiological status and the health condition of fish. The purpose of this paper was to evaluate the leukocyte reaction of rainbow trout after applying short periods of starvation (2 days and 4 days) and re- feeding with different dietary protein levels. Six experimental variants in duplicate were created, as follows: two control groups, feed daily, ad libitum, with commercial pellets containing 41% crude protein (D41) and 50% crude protein (D50); two groups starved for 2 days (D2) and then fed with commercial pellets with 41% crude protein (D2/41), respectively 50% crude protein (D2/50) and two groups starved for 4 days (D4) and then fed with commercial pellets with 41% crude protein (D4/41), respectively 50% crude protein (D4/50). In order to determine the leukogram and absolute number of leukocytes, blood samples were taken, at the beginning and at the end of the experiment, in order to make smears that were coloured with May-Grunewald Giemsa panoptic method. Regarding the leukogram of rainbow trout it can be observed an insignificant decrease (p˃0.05) of the relative number of lymphocytes, respectively an insignificant increase (p˃0.05) of the relative number of neutrophils, while the case of the relative number monocytes, it was observed a significant decrease (p˂0.05) in fish starved for 2 days. The absolute number of leukocytes (×103 cells/μl bloods) registered no statistically significant changes (p˃0.05) between the experimental groups, while the absolute number of monocytes showed a significant decrease for the fish starved for 2 days. However, it can be concluded that application of short periods of starvation did not affect the immune defence system of the rainbow trout fish.
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