Nutritional potential of marine and freshwater algae as dietary supplements for growing rabbits

Abstract

The aim of this study was to investigate the effect of including marine and freshwater algae in rabbit diets on their performance, digestibility, carcass characteristics, and blood metabolites. One hundred growing male rabbits, aged 30 d and weighing 783.5 ± 2.01 g initial body weight, were randomly assigned to five treatment groups (n ¼ 20 rabbits). Five comparable dietary groups were formulated as follows: the control diet was a basal diet without aquatic plants inclusion, while the diets for the other four treatments included the basal diet plus 4% of marine algae (U. lactuca and P. capillacea) or freshwater algae (S. polyrrhiza and C. aegagropila). Compared with the control group, final body weight, daily weight gain, and feed conversion ratio improved significantly in UL group; followed by those in PC and SP groups (p < .05). Total digestible nutrients and digestible crude protein increased significantly in UL, PC and SP groups. Rabbits in the CA group had lower nitrogen intake, N digested, and N balance decreased than the other groups (p < .05). The UL group had dressing weight and meat protein significant increases, but the SP and CA groups had significant increases in liver, kidney, and spleen weights (p < .05). Including marine and freshwater algae reduced (p < .05) total lipids, total bilirubin, triglycerides, and cholesterol especially in the UL and PC groups, and similarly, HDL and LDL levels were lower in the UL, PC, and SP groups compared to the CA and control groups. In conclusion, the responses in performance, digestibility, and blood metabolites suggest that aquatic plants (with the exception of CA) have the potential to be a sustainable feedstock for growing rabbits' diets. HIGHLIGHTSUlva lactuca, Pterocladia capillacea and Spirodela polyrrhiza improve rabbits' performance. Marine and freshwater algae inclusion showed no signs of disease. Marine and freshwater algae reduced total lipids, triglycerides, and cholesterol.

The Effect of Sargassum siliquastrum Supplementation on Growth Performance, Cecal Fermentation, Intestine Histomorphology, and Immune Response of Japanese Quails

“…Abu Hafsa et al [ 5 ], on laying quails, and Rizk et al [ 31 ] on laying hens found that the dietary inclusion of marine seaweeds improved their performance. According to Abu Hafsa et al [ 32 ], the growth performance improved significantly in rabbits fed 4% marine seaweeds. Adding seaweed to bird diets improved growth and health, as well as improving intestinal microflora [ 33 ].…”

“…Similarly, Balasubramanian et al [ 36 ] showed that broilers fed red seaweed-supplemented diets exhibited improved nutrient digestibility. The total digestible nutrients increased significantly in rabbits fed 4% marine seaweed, according to Abu Hafsa et al [ 32 ]. The current study revealed that growing Japanese quails fed S. siliquastrum performed as good as, or better than, quails fed a control diet.…”

Marine Macroalgae in Rabbit Nutrition—A Valuable Feed in Sustainable Farming

“…The protein content varies among groups, with red algae having the highest percentage (up to 47%) and brown algae the lowest (5–15%), and it is generally of very good quality in all types due to the high content of essential amino acids [ 69 ]. Seaweeds are a rich source of minerals, as they contain high levels of potassium, sodium and calcium, as well as iron, zinc, iodine, manganese, copper, cobalt and selenium [ 63 , 71 , 72 ] and also high levels of vitamins, especially vitamins A, C and E and the B group vitamins (B1, B2 and B12) [ 71 , 73 ]. Seaweeds also contain large amounts of PUFAs, particularly omega-3 and omega-6, which are present in a balanced ratio [ 69 , 71 , 72 ].…”

“…Seaweeds are a rich source of minerals, as they contain high levels of potassium, sodium and calcium, as well as iron, zinc, iodine, manganese, copper, cobalt and selenium [ 63 , 71 , 72 ] and also high levels of vitamins, especially vitamins A, C and E and the B group vitamins (B1, B2 and B12) [ 71 , 73 ]. Seaweeds also contain large amounts of PUFAs, particularly omega-3 and omega-6, which are present in a balanced ratio [ 69 , 71 , 72 ]. They are also rich in polyphenolic compounds (such as flavonoids and tannins), which act as strong antioxidants [ 69 , 70 , 71 , 73 ].…”

“…Very few studies have evaluated the inclusion of seaweed in the diets of rabbits, and in most of the studies, the main objective has been to evaluate the potential prebiotic effects on gut health. Two studies performed in Egypt [ 72 , 79 ] evaluated the effect of including whole algae (sun-dried) on the growth performance and gut health of growing rabbits. In both cases, the inclusion of 1% Ulva lactuca had positive effects on the growth performance and digestive health parameters of rabbits.…”