Evaluating the Effect of Using Different Levels of Sunflower Hulls as a Source of Fiber in a Complete Feed on Naemi Ewes’ Milk Yield, Composition, and Fatty Acid Profile at 6, 45, and 90 Days Postpartum

Abstract

This study was conducted to evaluate the effect of using different levels of sunflower hulls (SFH) as a source of fiber in a complete feed on Naemi ewes’ milk yield, composition, and fatty acid profile at 6, 45, and 90 days postpartum. In this study, 48 primiparous lactating Naemi ewes were randomly selected for the four treatment groups as follows: C (control), total mixed ratio (TMR; 0% SFH); TMR1, including S12% SFH; TMR2, including S20% SFH; and TMR3, including S28% SFH. The data were analyzed by SAS software 9.4 as a complete randomized design with repeated measurements. Both the S20 and S28 groups showed significant effects on milk yield and persistence at 45 and 90 days compared to the control and S12 groups. The triglyceride concentration level at 6 and 90 days postpartum was significantly higher (p < 0.05; p < 0.001) in the blood serum. The treatment significantly affected fat, protein, and total solids (p < 0.05), with quadratic and cubic responses, respectively. The time significantly influenced protein (p < 0.001), lactose (p < 0.01), and total solids (p < 0.05). A significant difference (p < 0.05) in the treatments showed varying responses in the fatty acid concentration in milk. Saturated fatty acids (SFAs) and omega 6 (n-6)/omega 3 (n-3) in the milk fat of ewes from the S12, S20, and S28 groups were significantly lower compared to the others. Furthermore, the (n-6) and atherogenicity (AI) were high and low, respectively, in S28, which is considered beneficial to human health. In conclusion, ewes can be fed up to 28% SFH during lactation as a complete pelleted feed to obtain an acceptable milk yield, nutritive value, and healthy fatty acid profile.