Effect of dietary kefir on the growth performance, feed utilization and fatty acid profile of juvenile rainbow trout,Oncorhynchus mykiss

Abstract

A study was conducted to determine the effect of feeding with diets containing kefir on growth performance and fatty acid profile of rainbow trout (Oncorhynchus mykiss). Four isonitrogenous (450 g protein kg−1) and isocaloric (4325 kcal kg−1) diets were prepared in trout feed to contain 0 (control), 20, 50 and 100 g kg−1 kefir. Fish, initial weight of 46 g, were randomly distributed into triplicate 520‐L fibreglass tanks in freshwater flow‐through system. Fish were fed at 4% of the body weight thrice a day for 12 weeks. The results indicated that survival rate ranged from 97.14 to 100% without significant difference among treatments (p > .05). Whole‐body moisture and lipid composition were significantly affected by diets containing different levels of kefir (p < .05), but no differences were determined in protein and ash. Furthermore, the fatty acid profile of flesh showed differences among the groups. The percentages of saturated fatty acid in the flesh lipid decreased, while 18:3n‐3 and polyunsaturated fatty acids were increased at higher substitution levels of kefir grain. The present study showed that up to 100 g kg−1 supplementation of kefir in diets could be improve the fatty acid profile, especially PUFA, in fish flesh without adverse effect on the growth, feed utilization and survival rate of rainbow trout.

The Effects of Kefir Usage for Probiotic Purpose on Growth Performance of Brook Trout (Salvelinus fontinalis)

“…While this study reached the conclusion that kefir addition improved feed utilization, the results were in parallel to those of a study which reported that kefir addition did not affect feed conversion ratio (Gumus et al, 2017). There are also other studies which reported that probiotics addition improved feed utilization (El-Haroun et al, 2006;Van Doan et al, 2016).…”

“…The best survival rate in this study was found in the group G2 with 20 ml/kg feed kefir addition by 98.88±0.51%. Another study added kefir into feed of the rainbow trout in different rates (2.5 and 10%), and found that 10% kefir-supported feed provided a significant increase in the immunity values of the fish and increased its survival rate against disease factors (Gumus et al, 2017). In a study by El-Haroun et al, (2006) on tilapia fish, it was reported that adding probiotics into feed in different rates reduced the effect of stressors.…”

“…However, there are a limited number of studies which focused on using kefir, which has probiotic properties, in aquaculture. The studies that were reviewed usually focused on the Coruh trout and the rainbow trout (Can et al, 2012a;Can et al, 2012b;Can et al, 2014;Ulukoy et al, 2015;Ulukoy et al, 2016;Gumus et al, 2017). In Turkey, commercial probiotic products are usually imported from abroad and this increases feed costs (Karademir et al, 2012).…”

Effects of Dietary Sage, Myrtle and/or Probiotic Mixture on Growth, Intestinal Health, Antioxidant Capacity, and Diseases Resistance of Oncorhynchus mykiss

“…The PM was prepared to contain lactic acid bacteria (Lactobacillus spp., Lactococcus spp., Lactobacillus acidophilus), Bifidobacterium spp., one yeast strain (Kluyveromyces marxianus) was isolated from kefir (Kök Taş et al 2012;Gümüş et al 2017) and Lactobacillus sakei from rainbow trout intestines (Didinen et al 2018). The lactic acid bacteria were grown on De Man, Rogosa and Sharpe (MRS) Broth (Merck 110661) and incubated for 24 hr at 25 °C.…”