Effect of replacing dietary soybean meal with pumpkin (Cucurbita pepo) seed cake on growth, feed utilization, haematological parameters and fatty acid composition of mirror carp (Cyprinus carpio)

Abstract

A 63-day feeding trial was conducted to evaluate the effects of replacing soybean meal (SBM) with pumpkin seed cake (PSC) as an alternative feed ingredient on growth performance, feed utilization, haematological parameters and the fatty acid profile of carp fingerlings. Four experimental diets were designed in which 0% (Control), 33% (PSC33), 66% (PSC66) and 100% (PSC100) SBM protein were replaced by an equivalent percentage of PSC protein. The fish (average weight of 16.24 g) were randomly distributed to 12 tanks in a recirculating aquaculture system and fed twice daily to satiation during the experimental period. The fish fed the PSC diets had better growth and feed utilization parameters compared to those of the control. The FW, WG, SGR and FCR in PSC66 were significantly higher than those in the control, while the haematological parameters were not affected by substitution of SBM with PSC. Serum total protein, albumin, albumin globulin ratio, glucose, alanine aminotransferase and aspartate aminotransferase levels were similar among the treatments, whereas cholesterol and triglyceride levels decreased with increasing PSC inclusion. The SFA, MUFA and n-3 PUFA content of fish muscle were not affected by the treatments. Additionally, linoleic acid, n-6 PUFA and the PUFA/SFA ratio in the control were significantly higher than those in the PSC100 treatment, but no significant differences were observed between the control and treatments PSC33 and PSC66. The results of this study indicate that dietary PSC can totally replace SBM without a negative impact on the growth and health status of carp.