Impact of dietary fats on histological alterations in the kidney tissue of Asian catfish, Clarias batrachus (Linnaeus, 1758)

Abstract

Various fats in the diets were used to evaluate their impact on the kidney tissues of Asian catfish (Clarias batrachus). There were seven (F1-F7) treatments (FISOL, BETAL, SOYAL, LINOL, MIXOL, SATOL and NATFO containing Fish oil, Tallow, Soybean oil, Linseed oil, Mixed oil (i.e. containing 1:1:1:1 ratio of Fish oil, tallow, Soybean oil and Linseed oil), Vegetable oil and minced chicken carcass as natural food, respectively, each having 3 replications, stocked @ 30 grow-out with an initial average weight 55.83 + 3.14 g in a circular plastic pools (cap. 300 L). Kidney of 3 fishes from each treatment were excised and processed for routine histological evaluation. The cellular changes in kidney tissues, following dietary fat incorporation, were assessed under light microscopy. F-1, fed fishes showing normal renal tubules and glomeruli; F-2, showing normal renal tubules, glomeruli and some vacuolation; F-3, exhibiting vacuolation, normal renal tubules and shrunken glomeruli with Bowman’s space; F-4, fed fishes exhibiting normal renal tubule, vacuolization and larger cavity in Bowman’s space; F-5, showing normal renal tubule, vacuolizationrnand Bowman’s space and F-6, fed fishes showing disrupted renal tubules, more vacuolization and Bowman’s space. Kidney of C. batrachus fed with natural food (NATFO, F7) showing normal renal tubules and glomeruli. The results exhibit some cellular changes in the kidney tissue like vacuolization, disrupted renal tubules and shrunken glomeruli which were recorded with minimum cellular effects, on addition of different dietary fats through feed. It was concluded that addition of dietary fats has some role in the cellular changes, in the kidney tissues in this fish however, the fat could be safely be used for better flesh quality and to reduce the feed cost.