Rainbow trout, a salmonid species has an economic importance worldwide and contributes to the indigenous food security. The present study was conducted in complete randomized design (CRD) to evaluate the dietary inclusion of citric acid with phytase as supplement on growth responses of rainbow trout. There were four treatments of diets with 0.5% citric acid (T1), 1% citric acid (T2), 1.5% citric acid (T3) and 0% control (T4) of citric acid incorporated with 1200FYT phytase as supplement. The treatments were replicated three times. Total harvest weight of fish in T3 (5720.2±105.6g) was significantly higher and different than T2 (4595.9±434.9g), T1 (4589.8±240.2g) and T4 (4567.5±217.3g). The highest daily growth rate was seen in treatment T3 (1.1±0.0) which was significantly different than T2 (0.9±0.0), T1 (0.9±0.0) and T4 (0.8±0.0). The highest specific growth rate was seen in the treatment T3 (0.8±0.01) which was significantly different than T1 (0.7±0.0), T2 (0.7±0.1) and T4 (0.7±0.0). The lowest food conversion ratio was seen in T3 (2.2±0.1) which was significantly different with T2 (2.6±0.1), T1 (2.7±0.1) and T4 (2.8±0.1). Similarly, the highest protein efficiency ratio was seen in treatment T3 (1.0±0.1) which was not significantly different with T2 (0.8±0.0) and T1 (0.8±0.1) but was significantly different than T4 (0.7±0.0). No significant changes were observed in water temperature, dissolve oxygen and pH under different treatments. The present findings demonstrated that dietary inclusion of citric acid with phytase as supplement enhance growth by reducing the pH in the gut which increases the phytate hydrolysis, kills the pathogens, decreases the rate of gastric emptying, improves mineralization and nutrient absorption.

Qualitative studies on chhana were carried out at Sindh Agriculture University Tandojam during the year 2011-12. Two milk sources (i.e. cow milk and buffalo milk) and three coagulants (i.e. acetic acid, citric acid and lactic acid) were used during the study period. Physical characteristics such as titratable acidity and pH values. Preliminary, the chhana was prepared from each of cow and buffalo milk coagulated with acetic acid, citric acid, and/or lactic acid each at 0.5, 1, 2 and 4% concentration level. Among each coagulant, concentration level showed significant influence on the acceptability score of chhana. Product made with 0.5% concentration level perceived the better acceptability (score). A remarkable influence of milk source was observed in pH values of chhana prepared from cow milk and buffalo milk either with acetic acid (5.65±0.01 and 5.45±0.01, respectively) or with citric acid (5.52±0.02 and 5.45±0.01, respectively). In this study, buffalo milk chhana was found better in all aspects compared to that of cow milk.