Potentials to differentiate milk composition by different feeding strategies

• Published in: Journal of dairy science Vol. 92; no. 5; pp. 2057 - 2066
• Main Authors: Slots, T., Butler, G., Leifert, C., Kristensen, T., Skibsted, L.H., Nielsen, J.H.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.05.2009; American Dairy Science Association; Am Dairy Sci Assoc; Elsevier
• Subjects: alpha-tocopherol; animal husbandry; Animal productions; Animals; antioxidant; Biological and medical sciences; Cattle - metabolism; Cattle - physiology; corn silage; cow feeding; dairy cow diet; dairy cows; Dairying - methods; Diet - veterinary; extensive farming; Fats - analysis; Fatty Acids, Omega-3 - analysis; Fatty Acids, Omega-6 - analysis; feed concentrates; feed grains; feed intake; feed rations; Feeding Methods - veterinary; Female; Food industries; Food, Organic - analysis; Fundamental and applied biological sciences. Psychology; grass silage; grazing; Lactation; linolenic acid; low input agriculture; Milk - chemistry; Milk - metabolism; Milk and cheese industries. Ice creams; milk composition; milk yield; monounsaturated fatty acids; organic milk; organic production; pastures; plant products; polyunsaturated fatty acids; Principal Component Analysis; ratio between n-6 and n-3; Regression Analysis; Terrestrial animal productions; Vertebrates; Denmark; United Kingdom; antioxidant; ratio between n-6 and n-3; dairy cow diet; organic milk; Farming animal; Dairy cattle; Dairy product; Antioxidant; Feeding; Vertebrata; Mammalia; Diet; Dairy industry; Strategy; Chemical composition; Ratio; Artiodactyla; Ungulata; Milk
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2008-1392

To investigate the effect of the dietary intake of the cow on milk composition, bulk-tank milk was collected on 5 occasions from conventional (n=15) and organic (n=10) farms in Denmark and on 4 occasions from low-input nonorganic farms in the United Kingdom, along with management and production parameters. Production of milk based on feeding a high intake of cereals, pasture, and grass silage resulted in milk with a high concentration of α-linolenic acid (9.4±0.2 mg/kg of fatty acids), polyunsaturated fatty acids (3.66±0.07 mg/kg of fatty acids), and natural stereoisomer of α-tocopherol (RRR-α-tocopherol, 18.6±0.5 mg/kg of milk fat). A milk production system using a high proportion of maize silage, by-products, and commercial concentrate mix was associated with milk with high concentrations of linoleic acid (LA; 19.7±0.4 g/kg of fatty acids), monounsaturated fatty acids (27.5±0.3 mg/kg of fatty acids), and a high ratio between LA and α-linolenic acid (4.7±0.2). Comparing these 2 production systems with a very extensive nonorganic milk production system relying on pasture as almost the sole feed (95±4% dry matter intake), it was found that the concentrations of conjugated LA (cis-9,trans-11; 17.5±0.7 g/kg of fatty acids), trans-11-vaccenic acid (37±2 g/kg of fatty acids), and monounsaturated fatty acids (30.4±0.6 g/kg of fatty acids) were higher in the extensively produced milk together with the concentration of antioxidants; total α-tocopherol (32.0±0.8 mg/kg of milk fat), RRR-α-tocopherol (30.2±0.8 mg/kg of milk fat), and β-carotene (9.3±0.5 mg/kg of milk fat) compared with the organic and conventional milk. Moreover, the concentration of LA (9.2±0.7 g/kg of fatty acids) in milk from the extensive milk production system was found to approach the recommended unity ratio between n-6 and n-3, although extensive milk production also resulted in a lower daily milk yield.