Effects of Fermented and Non-fermented Green Seaweed Supplementation on Performance, Caecal Bacterial Population, and Blood Constituents of Japanese Quails

Green Seaweeds are a valuable feedstock that can be utilized in poultry feed. Due to their recalcitrant polysaccharide structure, their use is still limited in poultry farming. This structure can be broken by a biotechnological approach such as solid-state fermentation (SSF) such as Trichoderma reesei, which simultaneously increases the nutritional value of the biomass. The current study aimed to investigate the effect of supplementation of fermented and non-fermented green seaweed (Ulva lactuca) on growth performance, nutrient digestibility, carcass characteristics, caecal microbiota, serum biochemistry, and antioxidant status in growing Japanese quails. Japanese quails (n = 375; one day old) were divided into five groups, with three replicates per group (25 quails in each replication). The quails were fed with five experimental diets, namely a control diet (basal diet without supplement), a basal diet supplemented with 1% and 2% green seaweed (GS) as well as 1% and 2% fermented green seaweed (FGS) for 42 days. The results showed that the groups fed FGS had a greater body weight gain and better feed conversion ratio than the other groups. The FGS groups showed the highest digestibility of crude protein and crude fiber, followed by the GS groups. FGS supplementation decreased abdominal fat percentage while increasing the bursa of Fabricius weight. The count of Lactobacillus was significantly increased in quails fed either GS or FGS, while Clostridium perfringens and Escherichia coli were decreased. The green seaweed-fed groups had significantly greater total protein, albumin, and globulin levels than the control group. Total lipids, triglycerides, cholesterol, HDL, and LDL were decreased in quails-fed diets containing 1% and 2% FGS. The quails in FGS diet groups had higher levels of total antioxidant capacity, catalase, and superoxide dismutase than the other groups, but lower levels of MDA. In conclusion, adding up to 2% fermented Ulva lactuca to the basal diet of Japanese quail promotes the growth and health of quails.