Potassium diformate in the diet of sterlet sturgeon ( Acipenser ruthenus ): Zootechnical performance, humoral and skin mucosal immune responses, growth‐related gene expression and intestine morphology

Abstract

This study evaluated the dietary effect of potassium diformate (KDF) on growth performance, body composition, humoral and skin mucosal immune responses, growthrelevant gene expression and intestine histomorphology in sterlet sturgeon. Sterlet fingerlings (N = 270; 6.86 ± 0.14 g) were scattered randomly into 18 tanks (six experimental diets in triplicate groups) and fed with incremental levels of KDF including 0 (control), 3 (KDF 3 ), 6 (KDF 6 ), 9 (KDF 9 ), 12 (KDF 12 ) and 15 (KDF 15 ) g kg −1 for 70 days.The groups fed with KDF 6 and KDF 9 diets presented significantly higher growth indices and whole-body protein content, whereas the lowest feed conversion ratio was measured in these treatments compared with other groups (p < .05). Total immunoglobulin, lysozyme activity and total protein levels in the serum and skin mucus samples were increased by increasing the levels of KDF, and the highest values were obtained in KDF 9 . The expression levels of growth hormone, ghrelin, and insulin-like growth factor-I genes were notably upregulated in KDF 9 compared with the control, KDF 3 and KDF 15 groups. The villus length and width of hind-gut were more than doubled in KDF 9 treatment compared with the control group (p < .05). These results showed that the application of KDF in sterlet diet had the potential to achieve high overall performance, and also, the optimum inclusion level of KDF ranged from 8.48 to 8.83 g kg −1 based on the second-order polynomial analysis models.

The Effects of Different Levels of Potassium Diformate and Calcium Diformate on Growth, Digestion Enzyme Activity, Antioxidant Capacity, Intestinal Flora, Stress Markers, and Some Serum Biochemical Analytes in Juvenile Beluga Huso huso

“…However, dietary supplementation of KDF at 12 and 15 g/kg did not improve growth performance in hybrid tilapia [39]. Kakavand et al [40] observed similar effects of improved KDF in the freshwater sturgeon, sterlet (Acipenser ruthenus), but the concentration used in their study was 9 g/kg feed, which is much higher than the concentration used in our study. Differences in nutrition and digestive system structure between A. ruthenus and H. huso may account for the observed difference in concentration.…”

Dietary powder and molecular imprinted polymer nanoencapsulated sodium propionate to enhance growth performance, digestive enzymes activity, antioxidant defense, and mucosal immune response in African cichlid (Labidochromis lividus) fingerlings

“…Sotoudeh et al (2020) reported that administration of diets supplemented with blends of organic acids (sodium propionate and sodium acetate) for eight weeks increased plasma lysozyme and ACH50 of yellowfin seabream (Acanthopagrus latus) juveniles. Total immunoglobulin and lysozyme activity increased in the serum and skin mucus of sterlet sturgeon (Acipenser ruthenus) with increasing the dietary levels of potassium diformate (KDF) (Kakavand et al, 2021). In another study, Safari et al (2017) showed up-regulation of immune-related genes expression with increasing lysozyme activity and Ig level in the skin mucus of common carp (C. carpio) fed SP-supplemented dies for eight weeks.…”

“…organic acids and their salts effectively enhance the growth, nutrient utilization, and health status of aquatic animals (Agouz et al, 2015;Safari et al, 2016;Chow et al, 2017). These improvements are attributed to a significant decrease in pH of the gut and upper intestinal tract (Baruah et al, 2005;Abu Elala and Ragaa, 2015), an increase in the digestive enzyme activities (Su et al, 2014;Castillo et al, 2014), stimulating the growth of intestinal epithelial cells (Topping and Clifton, 2001;Gao et al, 2011;Kakavand et al, 2021), improvement in the digestibility of major nutrients (Morken et al, 2011), and altering the gut microbial community (Silva et al 2016). Van der Wielen (2002) reported that butyrate is less ideal as a feed additive for animals because of its quick absorption in the upper digestive tract.…”