Blood Performance: A New Formula for Fish Growth and Health

Abstract

Monitoring fish health in a repeatable and accurate manner can contribute to the profitability and sustainability of aquaculture. Haematological and blood biochemistry parameters have been powerful tools and becoming increasingly common in aquaculture studies. Fish growth is closely related to its health status. A fish with a higher growth rate is more likely to be a healthy one. Any change in the physiological status of the fish, from pollution to nutritional stress, can cause changes in the blood parameters. Various aquaculture studies have measured the following components: red blood cells, white blood cells, haemoglobin, haematocrit, and total protein. However, because these parameters do not always follow the same trend across experimental fish, it is difficult to draw a firm conclusion about which parameter should be considered. Therefore, Blood Performance (BP) as a new formula is introduced, which is a more reliable indicator. This formula is simple and sums up the natural logarithm of the five above-mentioned parameters. More than 90 published peer-reviewed articles that measured these five parameters in the last six years confirmed the reliability and validity of this formula. Regardless of which supplements were added to the diets, the fish with a higher growth rate had higher BP as well. In addition, in 44 studies out of 53 articles, there was a significant positive correlation between specific growth rate and BP. Under different stressful situations, from pollution to thermal stress, the fish under stress had a lower BP than the control. Fish meal and fish oil replacement studies were further evidence for this formula and showed that adding excessive alternative proteins decreased growth along with BP. In conclusion, BP can be a reliable indicator of fish health and growth when it is compared between groups in the same experiment or farm. Although there was a positive correlation between specific growth rate and BP, comparing BP between experiments is not recommended. Standardising the haematological assays can improve the reliability and accuracy of BP across experiments.

Early Mild Stress along with Lipid Improves the Stress Responsiveness of Oscar (Astronotus ocellatus)

“…The tubes were centrifuged at 13,000 × g for 5 minutes in a microhematocrit apparatus before Ht values were determined using a specific graded sheet [21]. Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) [22], and blood performance (BP) [23] were calculated according to the below formula: ), and alanine aminotransferase (ALT) were measured using the kits from the Pars Azmun Company (Pars Azmun, Karaj, Iran). The antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA), were determined using ELISA kits analysis (ZellBio, GmbH, Germany) [24].…”

Should we farm beluga ( Huso huso ) in fresh water or brackish water?—The case study on taurine requirement

“…However, in general, salinity played a key role in changing liver enzymes in beluga; it can be claimed that fish was healthy in BW in terms of liver enzymes. Blood Performance was introduced recently as a biomarker of health and growth in fish (Esmaeili, 2021). The results indicated that this parameter in BW was significantly higher than that in FW (Slami et al, 2021), showing a sign of good health and growth in the BW group.…”

A blend of Guava, Bitter, and Neem Leaf extracts improves haematology and resistance to co-infection of Streptococcus agalactiae and Aeromonas jandaie but not Liver health in Nile tilapia

“…Fish health is now increasingly monitored using haematological variables such as red blood cells (RBC), white blood cells(WBC), haemoglobin (Hb), and haematocrit (Hct) [ 30 ]. WBC in blood help with immune responses in an organism; Hb plays a critical role in metabolism; RBC determines the status of oxygen delivery to tissues in the organism; and haematocrit (Ht) determines the volume of RBC [ 31 ]. In this experiment, we observed that fish fed the control diet showed normality of haematological variables reported in cultured Nile tilapia [ 32 ].…”