1. LOGO Effects of Adding Extruded Flaxseed on Milk Fatty Acids in Holstein Dairy Cows Ali Mahdavi Faculty of Veterinary Medicine, Semnan University, Iran

2. Outline 2  Introduction  Materials and methods Experiment site and Aniaml characteristics Nutrition and diet Measuring milk compounds Statistical analysis  Results  Conclusion

3. Introduction  Milk and dairy products are among important sources of nutritional foods  Milk and dairy products play an essential role in providing nutrients, including energy, protein, vitamins, and minerals. 3

4. Introduction 4 CLA 1 Anti-cancer Immune booster properties 2 3 Delaying arteriosclerosis Delaying diabetes 4 Add Your Text Health Benefits of Conjugated Linoleic Acid (CLA) Dietary polyunsaturated fatty acids (PUFA) are perceived to be healthier than saturated fatty acids (SFA).

5. Introduction 5

6. 6 Most oil seeds consumed by livestock contain triglyceride fat which consists of linoleic acid and linolenic acid.

7. Introduction 7 Flaxseed is one of the highest non-fish sources of omega-3 fatty acid and contains about 41% oil and over 20% protein.

8. Introduction  The present study attempts to examine effects of different levels of extruded flaxseed in diets fed to dairy cattle on saturated and unsaturated acids in milk. 8

9. Materials and methods  Experiment site and Animal characteristics:  The present study was conducted at Cattle Section of Laban Farming and Livestock Company.  15 Holstein dairy cows at their third and fourth parturition with average lactation period of 105 days with average milk production of 26 kg per day were kept for 42 days in three groups (each with 5 replicates).  The cows were fed completely mixed diets twice a day (in the morning and afternoon) and were milked three times a day at 5:30 AM, 13 PM, and 21:30 PM. 9

10. Materials and methods  Nutrition and diet:  Nutritional requirement and diets were formulated using the standard nutrition table (NRC 2001) for the cows.  Based on the research objectives: Three experimental diets were developed: Diet 1: 0% extruded flaxseed + 4% complete soybeans + 1.3% fat powder. Diet 2: 1% extruded flaxseed + 3.5 complete soybeans + 0.8% fat powder. Diet 3: 2% extruded flaxseed + 3 complete soybeans + 0.3% fat powder. 10

11. Materials and methods  Measuring milk compounds:  In order to determine percentage of fatty acids and prepare a profile for milk samples in the experiments, the method proposed by Jiang et al. (1996) was first used to extract total fat from milk.  GC method based on the standards 8188 and 8819 attached to this dissertation was used in Kimia Novin Laboratory to determine fatty acid content. 11

12. Materials and methods  Statistical analysis:  Complete randomized block design  Three groups (each with 5 replicates)  42-day  The resulting data were analyzed through SAS.  Repeated measurement method in Proc Mixed was used to analyze those parameters related to milk compounds that were measured more than once during the experimental period. 12

13. Results 13 Average total saturated fatty acids Average total unsaturated fatty acids Diet 1(Control) 68.4 a 27.8 c Diet 2 60.7 b 37 b Diet 3 58.2 c 40 a SEM 1.17 1.36 Diet 1: 0% extruded flaxseed + 4% complete soybeans + 1.3% fat powder. Diet 2: 1% extruded flaxseed + 3.5 complete soybeans + 0.8% fat powder. Diet 3: 2% extruded flaxseed + 3 complete soybeans + 0.3% fat powder. Table 1: Effects of extruded flaxseed on average total saturated and unsaturated fatty acids in Holstein dairy cows

14. Results 14 Average concentration α-linolenic acid (ALA) Average concentration conjugated linoleic acid (CLA) Diet 1(Control) 0.28 c 0.31 c Diet 2 0.56 b 0.45 b Diet 3 0.68 a 0.72 a SEM 0.0520.047 Diet 1: 0% extruded flaxseed + 4% complete soybeans + 1.3% fat powder. Diet 2: 1% extruded flaxseed + 3.5 complete soybeans + 0.8% fat powder. Diet 3: 2% extruded flaxseed + 3 complete soybeans + 0.3% fat powder. Table 2: Effects of extruded flaxseed on average concentration α-linolenic acid (ALA) and conjugated linoleic acid (CLA) in Holstein dairy cows

15. Conclusion Improve the nutritive value of milk Extruded Flaxseed Increase concentrationsUSFA 15 Increase concentrationsALA Increase concentrationsCLA Decrease concentrationsSFA