Effect of Omega 3 fatty acids from cow ' s milk obtained from cows fed different rations of flaxseed on functional yoghurt properties

This work aimed to investigate the effect of supplementing different form of whole linseed (or oil seed or meal) to lactating cow's ration on milk yield and milk composition. Sixteen multifarious Friesian cows 15±2.26 kg/d of milk and averaging 500±15.26 kg/body weight, were divided into four experimental feeding groups (4 each) for 180 days. The first group (A) used as a control, linseed meal group (B), whole linseed group (C) and linseed oil group (D). All experimental rations were almost equals in energy and protein. Results indicated that supplementation of linseed meal recorded the highest FCM (13.60 kg/h/d). There was no significant difference in milk composition among groups. Supplementation linseed oil (D) reduced the apparent digestibility of CF compared with control. The different form of oil seed did not influence ruminal pH but it caused significant (P<0.05) increased in ruminal ammonia concentrations for (C) and (D) compared with control. While, the concentration of ruminal volatile fatty acids was significantly (P<0.05) differ for cows feed (B) and (D) except those fed rations (C) compared with control diet. From the previous results, it could be concluded that usinglinseeds, especially meal, in lactating cow’s rations increased milk yield without adverse effects on cow’s health or performance. Thirteen functional yoghurt samples were carried out using milk samples obtained from the 4 cows of each group. Every week of storage period, functional yoghurt samples were analyzed for fatty acids (FA) composition. Recoveries of fat, individual FA, and grouped FA were compute in functional yoghurt samples and in milk. Inclusion of whole linseed or linseed oil or linseed meal did not affect dry matter (DM), milk yield, and milk composition. Compared with control milk, the 3 diets containing whole linseed, linseed oil or linseed meal increased the proportion of C18:3, n-3 and total n-3 FA, in both milk and functional yoghurt It was found that functional yoghurt fat percentage was different among diets. Functional yoghurt made from milk obtained from lactating cows fed control diet (C) and yoghurt made from milk obtained from lactating cows fed ration contain whole linseed (WLS) or linseed oil (WLO) or linseed meal (WLM). The best treatment which contains the lowest value of omega-6/omega-3 ratio (n-6/n-3 ratio) in yoghurt treatments found in T7 treatment (yoghurt made from cow milk obtained from cows fed with WLO and inculcated with Bifidobacterium aldolescentis ATCC 15704 was (20.0), followed by T9 treatment ( yoghurt made from cow milk obtained from cows fed with WLS and inculcated with Bifidobacterium aldolescentis ATCC 15704,) was (20.08) followed by, T2 treatment (yoghurt made from cow milk obtained from cows fed with WLM and inculcated with B. lactis Bb.12) (20.99) compared with other treatments, but the highest value of omega-6/omega-3 ratio (n-6/n-3 ratio) was (45.83) found in the control yoghurt (C1 yoghurt made from cow milk obtained from cows fed with control diet and inculcated with yogurt culture ). The experiment confirmed that feeding cows with whole linseed, linseed oil or linseed meal represents a successful strategy for improving the fatty acids profile of functional yoghurt as dairy products, through an increase of omega 3 fatty acids. The experiment confirmed that feeding cows with whole linseed, linseed oil or linseed meal represents a successful strategy for improving the fatty acids profile of functional yoghurt as dairy products, through an increase of omega 3 fatty acids and decrease the value of omega-6/omega-3 ratio (n-6/n-3 ratio) in milk and all yoghurt treatments. Middle East J. Appl. Sci., 8(2): 523-542, 2018 ISSN 2077-4613 524