Abstract
Aim of the present study was to evaluate the effect of feeding dairy cows with extruded flaxseed (EF) on milk quality. After a 7-d adaptation period, 40 Holstein dairy cows in midlactation were divided in two experimental groups, based on parity, milk yield and composition, and days in milk. Animals were fed for 28 d a standard total mixed ration containing or not (control) 1.8 kg/cow/d of a supplement based on extruded flaxseed (EF). Milk yield was recorded daily and individual milk samples were collected weekly for analysis. Milk yield was not affected by treatment and averaged 26.2 kg/d throughout the study. Feeding EF reduced milk fat (3.95 vs. 4.24%; P=0.053) and tended to reduce milk protein (3.32 vs. 3.50%; P=0.104). The milk from cows fed EF contained more (P<0.01) stearic (12.0 vs. 7.8 mg/100 mg of fat), oleic (21.2 vs. 18.0 mg/100 mg of fat), ?-linolenic (0.85 vs. 0.41 mg/100 mg of fat) and vaccenic (1.43 vs. 0.62 mg/100 mg of fat) acids than control and also more c9,t11 CLA (0.91 vs. 0.59 mg/100 mg of fat). Conversely, compared with control, feeding EF reduced milk concentrations of palmitic acid (26.5 vs. 33.4 mg/100 mg of fat; P<0.01). The present results show that feeding EF to dairy cows is an efficient strategy to enrich milk in beneficial fatty acids such as vaccenic acid, CLA and omega-3 fatty acids. Nevertheless, the milk fat reducing effect of flaxseed as well as other sources of polyunsaturated fatty acids should be taken into account.
Highlights
During the last decades, consumer demand for improved food quality has considerably increased
All collected milk samples were analyzed for protein, fat and lactose by Milk-O-Scan whereas milk fatty acid profile was determined by gas chromatography in samples collected on Day 0 and 28
Feeding dairy cows with extruded flaxseed reduced milk fat by 7%
Summary
Consumer demand for improved food quality has considerably increased. There has been an increased tendency for consumers to use food that might help preventing disease. A food can be said to be functional if it contains a component (which may or may not be a nutrient) that affects one or a limited number of functions in the body in a targeted way so as to have positive effects on health (Bellisle et al, 1998). Among nutrients that might exert a positive effect on consumer health, specific fatty acids such as omega-3 fatty acids and conjugated linoleic acids (CLA) have gained attention. There is some evidence that CLA might alleviate major diseases such as cancer, atherosclerosis, diabetes and obesity (Benjamin and Spener, 2009)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
