Planta Med 2013; 79 - PL22
DOI: 10.1055/s-0033-1352330

Milk fatty acids in dairy cows supplemented with larch (Larix decidua L.) sawdust

D Tedesco 1, L Garavaglia 2, S Panseri 1
  • 1Dep. of Health, Animal Science and Food Safety (VESPA) University of Milan, Via Celoria 10, 20133 Milan, Italy
  • 2Dep. of Health, Animal Science and Food Safety (VESPA), University of Milan, Via Celoria 10, 20133 Milan, Italy

Larch (Larix decidua L., Pinaceae) wood is known to contain flavonols (mainly dihydroquercetin and dihydrokaempferol) which possess a high antioxidant activity comparable to that of α-tocopherol. This study was conducted to investigate whether larch sawdust (byproduct of larch wood production), supplemented to dairy cows, have effects on milk fatty acids composition and on the oxidative stability of milk.

Sixteen Italian Friesian dairy cows in mid lactation were used in a 5-wk study. All animals were fed a total mixed diet. Animals were divided into two groups, one treated group (n = 8) received 300 g/d of larch sawdust 1 and one negative control group (n = 8). The treatment lasted for 21 d. Milk fatty acids was determined on samples collected on day 20 and on the same samples after storing at 4 °C for four days. Milk stored at 4 °C for four days were analyzed also for hexanal content.

Milk yield was not affected by treatment. Total polyunsaturated fatty acids were higher in milk from cows fed with larch sawdust (p < 0.05) with an highest proportion of C20:3n-6 fatty acid (p < 0.01). The fatty acids in control milk after 4 days storage (4 °C) were more susceptible of oxidation. Milk from cows fed with larch sawdust was more resistant to fatty acids oxidation (PUFAs, p < 0.05). Despite its high polyunsaturated fatty acid content, milk from treated group was reasonably stable to oxidation with the lower hexanal production after 4 days of storage at 4 °C, than what observed in control milk (p < 0.01).

These results suggest that larch sawdust is an interesting resource of valuable feed additive as naturally antioxidant. Moreover larch sawdust being a waste product, could represent an economically valid tool, keeping in mind that, the development of integrated biorefinery processes should be needed. Further studies with other animal species will be necessary to confirm the application.

1provided by Jannach Lärchenholz GmbH, Thalheim, Austria- (SAFEWASTES, EU pr. 513949)