Haemato-biochemical responses and induction of HSP70 to dietary phosphorus in Catla catla (Hamilton) fingerlings

Evaluation of Heavy Metal Contamination in Some Selected Commercial Fish Feeds Used in Bangladesh

Quality fish feed is the prime need for successful aquaculture. Feed qualities determine the fish flesh quality including appearance, color, odor, flavor, texture, nutritive value, and shelf-life. Nowadays, consumers are very much concerned about various issues regarding way of fish farming, types of feed ingredients used etc. The current study was conducted to assess the heavy metal contents and nutritional composition of some selected commercial fish feeds used in Bangladesh. The major heavy metal concentrations and proximate composition (moisture, crude protein, crude lipid, ash, crude fiber, and carbohydrate) of the collected feed samples were analyzed. The results showed that the feeds contained a number of heavy metals in varying proportions. The highest concentrations (mg/kg) of heavy metals such as lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), and zinc (Zn) analyzed in fish feed samples were 0.189, 0.027, 1.023, 0.303, and 1.468, respectively. There were significant differences between the nutritive values provided by feed companies and the values observed in this finding. The present study recommends that adequate measures are required to be taken by commercial fish feed manufacturers to ensure the nutritional quality of feed as well as to avoid the contamination of feed from heavy metals. Otherwise, fish and human, the ultimate consumer, may be predisposed to the assimilation and accumulation of the assessed heavy metals.

Effect of phosphorus deficiency on erythrocytic morphology and function in cows

The aim of this study was to evaluate the influence of phosphorus (P) deficiency on the morphological and functional characteristics of erythrocytes in cows. Forty Holstein-Friesian dairy cows in mid-lactation were randomly divided into two groups of 20 each and were fed either a low-P diet (0.03% P/kg dry matter [DM]) or a control diet (0.36% P/kg DM). Red blood cell (RBC) indices results showed RBC and mean corpuscular hemoglobin decreased while mean corpuscular volume increased significantly (p ＜ 0.05) in P-deficient cows. Erythrocyte morphology showed erythrocyte destruction in P-deficient cows. Erythrocytes' functional characteristics results showed total bilirubin and indirect bilirubin concentrations and aspartate transaminase and alanine transaminase activity levels in the serum of P-deficient cows were significantly higher than those in control diet-fed cows. Activities of superoxide dismutase and glutathione peroxidase in erythrocytes were lower, while the malondialdehyde content was greater, in P-deficient cows than in control diet-fed cows. Na⁺/K⁺-ATPase and Mg²⁺-ATPase activities were lower in P-deficient cows than in control diet-fed cows; however, Ca²⁺-ATPase activity was not significantly different. The phospholipid composition of the erythrocyte membrane changed and membrane fluidity rigidified in P-deficient cows. The results indicate that P deficiency might impair erythrocyte integrity and functional characteristics in cows.