نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Extended Abstract
Introduction and Objective: Rapid growth during the fattening period in lambs is typically associated with increased metabolic activity and elevated production of reactive oxygen species, which can disrupt the balance between oxidant generation and antioxidant defense mechanisms. This imbalance leads to oxidative stress, resulting in lipid peroxidation, protein oxidation, and potential impairment of immune function. Nutritional interventions using natural antioxidant-rich feed ingredients have gained considerable attention as a strategy to enhance oxidative stability and modulate immune responses in ruminants. Camelina sativa, a promising oilseed crop, is known for its high content of polyunsaturated fatty acids—especially omega 3 fatty acids—as well as biologically active compounds such as tocopherols and phenolic antioxidants. These components contribute to reducing free radical activity, inhibiting lipid peroxidation, and supporting the overall antioxidant capacity of the organism. In contrast, palm oil, though commonly used in animal feeding systems for its energy density, contains relatively lower levels of antioxidant compounds.
Given the limited comparative information regarding the effects of palm oil, camelina oil, and whole camelina seeds on oxidative and immune parameters in fattening lambs, the present study was designed to evaluate their influence on key antioxidant indicators and immune markers. The main objective was to determine whether camelina-based dietary sources—particularly whole camelina seeds—could promote better oxidative balance and immune function compared with palm oil supplementation.
Materials and Methods: Thirty-two healthy male lambs (average age 3.5 months; initial body weight 23.89 ± 0.48 kg) were used in an 84 day feeding trial arranged in a completely randomized design with four treatments and eight replicates per treatment. The experimental diets included: (1) a basal diet without any oil supplement (control), (2) a basal diet supplemented with 1.5% palm oil, (3) a basal diet supplemented with 1.5% camelina oil, and (4) a basal diet supplemented with 5% whole camelina seeds. Diets were formulated to meet or exceed nutrient requirements for fattening lambs.
At the end of the feeding period, blood samples were collected from the jugular vein before morning feeding. Serum was separated and used to measure glutathione peroxidase (GPX) activity, malondialdehyde (MDA) concentration, and total antioxidant capacity (TAC). GPX was used as a marker of enzymatic antioxidant defense, MDA as an indicator of lipid peroxidation, and TAC as an index of the total non-enzymatic antioxidant potential. Additionally, immune-related cytokines, including interleukin 2 (IL 2), interleukin 6 (IL 6), and interleukin 10 (IL 10), were quantified using ELISA kits. Data were analyzed using the GLM procedure of SAS software, and treatment means were compared using appropriate statistical tests, with significance declared at P < 0.05.
Results and Discussion: Dietary treatments significantly affected the antioxidant indices measured. Lambs receiving whole camelina seeds exhibited the highest values of GPX activity and TAC among all groups, indicating a markedly enhanced antioxidant defense system. The increase in GPX activity reflects improved enzymatic detoxification of reactive oxygen species, while elevated TAC values demonstrate a greater availability of non enzymatic antioxidants in the serum. Camelina oil supplementation also improved GPX and TAC compared with palm oil and the control diet; however, the magnitude of improvement was consistently lower than that observed in the whole seed treatment.
The concentration of MDA followed an inverse pattern, with the palm oil group exhibiting the highest level of lipid peroxidation (3.15 ng/L), suggesting greater oxidative stress. In contrast, both camelina oil and particularly camelina seed treatments resulted in significantly reduced MDA concentrations, highlighting the superior antioxidant protection offered by camelina-derived bioactive compounds.
Cytokine analysis revealed notable differences in immune response across treatments. Levels of IL 6, a pro-inflammatory cytokine associated with stress and inflammatory processes, were significantly lower in lambs fed whole camelina seeds (0.34 ng/L). This reduction suggests that camelina seed supplementation helped attenuate inflammatory responses, likely due to the anti-inflammatory properties of omega 3 fatty acids and phenolic compounds. Likewise, IL 10 concentrations, representing anti-inflammatory immune activity, were highest in the camelina-containing diets, with whole camelina seeds showing the strongest effect. These findings indicate that camelina not only enhances antioxidant defense but also promotes a more regulated and balanced immune response.
The superior performance of whole camelina seeds compared to camelina oil may be attributed to the presence of additional bioactive components in the whole seed matrix, such as fiber-bound antioxidants, phytochemicals, or minor lipid fractions that are partially lost during oil extraction. This synergistic combination likely contributes to enhanced physiological effects beyond those provided by camelina oil alone.
Overall, palm oil, despite contributing extra dietary energy, did not improve oxidative or immune parameters and was consistently associated with higher oxidative stress indicators compared to camelina treatments. The results collectively emphasize the value of camelina-based ingredients as functional feed components capable of improving health status in lambs under intensive production conditions.
Conclusion: The findings of this study demonstrate that supplementation with camelina sources—particularly whole camelina seeds—effectively enhances antioxidant capacity and modulates immune responses in fattening lambs. Whole camelina seeds provided the most robust improvement in GPX activity, TAC, reduction of MDA levels, and favorable modulation of cytokine profiles. Camelina oil also showed beneficial effects, although to a lesser extent than whole seeds. In contrast, palm oil supplementation offered limited physiological benefits and was associated with higher oxidative stress markers. These results suggest that camelina seeds can serve as a valuable natural feed ingredient to support oxidative stability, reduce inflammatory responses, and promote better overall health in fattening lambs.
کلیدواژهها English
