Milk composition and fatty acids profile of grazing dairy cows after supplementation with cottonseed and linseed

  1. Roca-Fernández A.I 1
  2. Antonio González-Rodríguez 1
  3. Orlando Pablo Vázquez-Yáñez 1
  4. José Antonio Fernández-Casado 2
  1. 1 Agrarian Research Centre of Mabegondo. PO Box 10, 15080 La Coruña, Spain
  2. 2 Agrarian and Fitopathologic Laboratory of Galicia. PO Box 365, 15640 La Coruña, Spain
Proceedings:
Grassland farming and land management systems in mountainous regions. Proceedings of the 16th Symposium of the European Grassland Federation Gumpenstein, Austria August 29th - August 31st 2011

Publisher: European Grassland Federation

ISBN: 978-3-902559-65-4

Year of publication: 2011

Pages: 154-156

Type: Conference paper

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Abstract

7KHGLHWRIUXPLQDQWVLQÀXHQFHVWKHLUPLONFRPSRVLWLRQDQGIDWW\DFLG )$ SUR¿OH7KHHIIHFWof supplementation at pasture with two sources of forage (grass+silage (S) compared to ‘allgrazing’ grass (G)), and two types of concentrate (C, cottonseed and L, linseed) differing in)$SUR¿OHRIWKHWZRRLOVHHGFRPSRQHQWVZDVH[DPLQHGLQIRXUJURXSV 6&6/*&DQG*/ of autumn-calving Holstein-Friesian cows (n = 50). Milk yield and composition were determined across the main grazing season. The ‘all grazing’ treatments produced more milk, withhigher urea content, than the silage-supplemented grazing treatments, despite lower proteinDQGIDW7KHIRUDJHVRXUFHKDGDJUHDWHUHIIHFWRQPLON)$SUR¿OHWKDQWKHW\SHRIFRQFHQWUDWHused. The group of cows grazing all day had lower levels of short- and medium-chain FAthan those at grass-plus-silage. Higher content of long-chain (mono- and poly-unsaturated)FA was observed in milk from cows grazing all day. Daily intake of fresh grass was a decisivefactor for the highest conjugated linoleic acid (CLA) content. The addition of cottonseed inthe concentrate showed higher levels of long chain and mono-unsaturated FA than the use oflinseed. High reliance on grass at farm level would be a good tool to increase the CLA contentLQPLONIDWDQGJHWPRUHDGGHGYDOXHZLWKDQLPSURYHGPLON)$SUR¿OH