Objective: This study was conducted to investigate the effect of palm oil, camelina oil, and whole camelina seeds on performance, nutrient digestibility, feeding behavior, and fecal score in fattening lambs.

Method: Thirty-two male lambs (mean age 3.5 months and initial weight 23.89 ± 0.48 kg) were fattened in a completely randomized design with 4 treatments and 8 replicates for 84 days. The treatments included: 1- basal diet without oil supplement (control), 2- basal diet containing 1.5% palm oil, 3- basal diet containing 1.5% camelina oil, and 4- basal diet containing 5% camelina seed. Lambs were housed individually with ad libitum fresh water. Body weight was recorded every 28 days and daily feed intake was measured. Nutrient digestibility was assessed using acid‑insoluble ash (AIA) as an internal marker during the final two weeks. Feeding behavior was observed over 24 h by instantaneous sampling every 5 min, and time spent eating, ruminating, and resting was calculated. Fecal consistency was scored weekly on a 1–5 visual scale. Data were analyzed with the General Linear Model (GLM) in SAS 9.4 and means compared by Duncan’s test (α = 0.05). All procedures followed the university’s animal‑care guidelines.

Results: Results showed that although feed intake decreased in oil-supplemented treatments (P < 0.001), yet daily weight gain and feed conversion ratio were not affected by treatments (P > 0.05). Average daily feed intake was ~12 % lower in the oil groups compared with control, while average daily gain (ADG) remained around 185 g day⁻¹ across all treatments. The digestibility of dry matter, organic matter, crude protein, and neutral detergent fiber (NDF) in treatments containing palm oil and camelina oil was significantly (P < 0.05) lower than that of the camelina seed treatment, while crude fat digestibility increased in these treatments. Lambs fed camelina seed had the longest time spent eating, ruminating, and chewing during the day (P < 0.001). Fecal score at the end of the period in treatments containing camelina (oil and seed) was significantly higher (softer) than in the palm oil and control treatments, indicating looser stools. No clinical signs of digestive disturbance were observed.

Conclusions: In general, the use of camelina seed, due to the protective effect of the seed coat on the rumen environment, led to the preservation of nutrient digestibility and improved rumination behavior, and also affected fecal consistency. The physical form of fat supply (seed vs. free oil) is a key factor in its effect on digestive processes in fattening lambs Incorporating camelina seed can increase diet energy density while maintaining fiber utilization—a practical strategy for lamb producers. Future work should test higher seed inclusion levels and assess long‑term effects on carcass composition, especially omega‑3 fatty‑acid enrichment.