Red lentil screening by-product inclusion in rabbit diet: effects in growth traits, meat quality and gut health

Lentils, widely consumed as part of traditional diet, are well-known for their health-promoting properties. However, their industrial processing generates many by-products, such as red lentil screening (RLS), identified as promising animal feed. A total of 120 male Bianca Italiana breed growing rabbits, aged 42 days, were allotted to three dietary treatments containing different levels of RLS: 0 (RLS0), 5 (RLS5) or 10% (RLS10), respectively, for 6 weeks (4 rabbits/cage). At 84 days, meat, plasma and intestinal samples were collected. The rabbits were housed under identical environmental and sanitary conditions throughout the trial. No medication was included in feed or in drinking water, and rabbits’ health status was checked through individual observations. The RLS inclusion showed no adverse effects on growth performance. However, significant differences were found on meat fatty acid profile, where both RLS5 and RLS10 groups showed reduced C18:0 percentage and higher MUFA content owing to an increase in C18:1 n-9; moreover, RLS5 showed a significant increase in C16:1 trans. On the other hand, only RLS10 recorded a significant reduction of the PUFA total content due to decreased single unsaturated fatty acid. Dietary RLS significantly decreased serum total cholesterol, LDL and HDL along with an enhancement of serum antioxidant capacity (P<0.05). Rabbit caecal characteristics and microbial population were found to be similar among groups. However, referring to istomorphometric measurements, both RLS5 and RLS10 groups displayed a significant increase in villus height and in an improved villus height to crypt depth ratio (P<0.01). In conclusion, RLS in rabbits diet up to 10% can be considered an efforteffective feeding strategy to modulate rabbit meat fatty acid profile, to enhance endogenous antioxidant capacity, and to im-prove serum lipid profile and intestinal morphology. Research supported by EU funding within the Next GenerationEU-MUR PNRR based on DM 118/23, project “Green chemistry for sustainable innovation of production processes for animal nutrition”, under the first author’s PhD Programme in Organs and Tissues Transplantation and Cellular Therapies (XXXIX cycle) of the Department of Precision and Regenerative Medicine and Jonian Area, University of Bari Aldo Moro, Italy.