Effects of dietary hydroxy-cinnamic acid derivatives on growth, muscle, and intestinal parameters of Tilapia (Oreochromis niloticus).

Hydroxycinnamic acid derivatives are a class of phenolic acid compounds, including sinapic acid, ferulic acid, and caffeic acid, which are widely found in plants. This experiment was conducted to study the effects of hydroxycinnamic acid derivatives (sinapic acid, ferulic acid, and caffeic acid) on the growth performance, muscle physical parameters, and intestinal morphology of tilapia. A total of 320 tilapia fingerlings (9.99 ± 0.12 g) were randomly divided into 4 groups with 4 replicates per group and 20 tilapia per replicate. Each group was fed a basal diet (control group), and the experimental diet supplemented with 0.52 mmol/kg sinapic acid, ferulic acid, and caffeic acid, respectively. After 8 weeks of feeding, the growth indexes and serum indexes of tilapia were measured, and the body, muscle composition, and muscle physical parameters, as well as the intestinal morphology were analyzed. The results showed that the addition of hydroxycinnamic acid derivatives to the diets significantly increased the weight gain rate (WGR) compared with the control (p < 0.05), with improvements of approximately 14.93%, 27.27%, and 28.06% for sinapic acid, ferulic acid, and caffeic acid, respectively. In the caffeic acid and ferulic acid groups, the final mean weight (FBW) was significantly increased and the feed coefficient (FCR) was significantly decreased compared with the control (p < 0.05). Compared with the control group, the hydroxycinnamic acid derivatives group had significantly lower levels of aspartate aminotransferase (AST), glucose (GLU), triglyceride (TG), and lactate dehydrogenase (LDH) (p < 0.05), but had significantly higher levels of albumin (ALB), total protein (TP), alkaline phosphatase (ALP), and blood urea nitrogen (BUN) (p < 0.05). There were no significant differences in alanine aminotransferase (ALT) and total cholesterol (TCHO) among all groups (p > 0.05). Besides, moisture, crude protein, crude fat, and ash in whole fish and muscle among all groups showed no significant differences (p > 0.05). In addition, hardness, gumminess, adhesiveness, and resilience of muscle in tilapia fed the hydroxycinnamic acid derivative were significantly higher than that of the control group (p < 0.05). Chewiness, springiness, stringiness, and cohesiveness showed no statistically significant differences among the treatments (p > 0.05). The analysis of intestinal morphology showed that the villus height and muscle thickness of the foregut and hindgut in the fish fed hydroxycinnamic acid derivatives were significantly higher than those in the control fish (p < 0.05), but the villus width of the foregut and hindgut did not differ significantly among the treatment groups (p > 0.05). In conclusion, dietary hydroxycinnamic acid derivatives can improve the growth, muscle physical parameters, and intestinal morphology of tilapia. Ferulic acid and caffeic acid had stronger beneficial effects on tilapia than sinapic acid.