Impact of dietary inclusion of Gracilaria parvispora on digestibility, growth performance, and health status of lambs

Gracilaria parvispora, a red seaweed belonging to the Rhodophyta phylum, represents a particularly interesting option for ruminant nutrition. The inclusion of seaweed in ruminant diets presents a promising strategy for enhancing animal health and productivity by providing essential nutrients and minerals. This study aimed to characterize the chemical composition and mineral profile of brown (n = 8) and red (n = 3) seaweed species harvested from the Bay of Bengal, Bangladesh, and to evaluate the effects of dietary supplementation with Gracilaria parvispora on growth performance, nutrient digestibility, and health status in lambs. Eighteen lambs were assigned to three dietary treatments: control (0 g/kg dry matter [DM]), low (21 g/kg DM; 7 g/lamb/day or 2% of DM intake), and high (42 g/kg DM; 14 g/lamb/day or 4% of DM intake) inclusion levels of G. parvispora. Results indicated that all seaweeds are nutrient-rich, particularly in CP (88.3-122 g kg-1 DM), Ca (0.06-0.084 g kg-1 DM), Zn (76.1-164 ppm), and Fe (135-216 ppm). Lambs' DM and CP digestibility increased (4.1%) (p<0.05), and their average daily gain rose (p<0.05) when a low quantity (7 g/lamb/day) of G. parvispora was added to their diet. Blood protein, albumin, globulin, triglycerides, low-density lipoprotein, high-density lipoprotein, glucose, phosphorus, urea, uric acid, and creatinine were all unaffected (p>0.05) by G. parvispora supplementation, according to blood parameter data. However, when G. parvispora was added to the diet, fecal levels of coliform bacteria and alkaline phosphatase dropped (p<0.05), whereas IgM rose (p<0.05). In conclusion, seaweeds are a good source of nutrients for ruminants, according to the CP content, while CP digestibility, growth rate, immunity, and coliform bacterial load were all enhanced by adding G. parvispora (7 g/lamb/day) to their diet.