%0 Journal Article
%T Conjugated Linoleic Acid in Milk Fat of Grazing Dairy Cows Fed Fish Oil and Linseed Oil
%A W. Brown
%A A.A. AbuGhazaleh
%A S. Ibrahim
%J Research Journal of Dairy Sciences
%D 2012
%I 
%X The objective of this study was to determine the effect of supplementing grazing dairy cows  diet with Fish Oil (FO) and Linseed Oil (LSO) on milk Conjugated Linoleic Acid (CLA). Sixteen Holstein cows (170 19 DIM) were divided into 2 groups (n = 8 per treatment) and fed a basal diet (7.2 kg d 1; DM basis) consisting of corn, soybean meal, molasses, vitamin/mineral premix plus 800 g saturated animal fat (CONT) or a basal diet plus 200 g FO and 600 g LSO (FOLSO). All cows grazed together on Sudan grass pasture for ad libitum and fed the treatment diets for 3 weeks. Cows were milked twice a day and milk samples were collected during the last 3 days of the trial. Milk production (24.89 and 22.45 kg d 1), milk protein percentages (2.76 and 2.82) and milk protein yield (0.68 and 0.64 kg d 1) for the CONT and FOLSO diets, respectively, were not affected (p>0.05) by treatment diets. Milk fat percentages (3.90 and 2.86) and milk fat yields (0.97 and 0.64 kg d 1) were lower (p< 0.05) with the FOLSO diet compared with the CONT diet. The concentration and yield of milk cis-9 trans-11 CLA were higher (p< 0.05) with the FOLSO diet (2.56% of total FA and 16.44 g d 1, respectively) than the CONT diet (0.66% of total FA and 6.44 g d 1, respectively). The concentrations of milk trans C18:1 and Vaacenic Acid (VA) were higher (p< 0.05) with the FOLSO diet (36.99 and 7.48% of total FA, respectively) than the CONT diet (28.8 and 2.27% of total FA, respectively). In conclusion, supplementing grazing cows  diet with FO and LSO increased milk cis-9 trans-11 CLA content but reduced milk fat content and yield.
%U http://www.medwellonline.net/abstract/?doi=rjdsci.2007.6.12