BACKGROUND: A wide range of isomer-specific health benefits have been attributed to conjugated linoleic acids (CLAs). Little information is currently available on the influence of different feed components on the concentration of CLA isomers in ruminant-derived products. The aims of this study were to compare the effect of cereal mix or dried sugar beet pulp supplementations fed to grazing dairy cows on milk CLA isomeric distribution and to examine the monthly variation of CLA isomers during the grazing season. RESULTS: The concentrations of the isomers t7c9, t10c12 and t10t12 were higher in milk from cows supplemented with cereals (P ≤ 0.001). The milk of beet pulp-supplemented cows showed higher levels of the isomers t11c13 (P ≤ 0.05), t9t11 (P ≤ 0.001) and t7t9 (P ≤ 0.01). Total CLA as well as seven other minor isomers were not significantly affected by the concentrate type. Monthly variations occurred extensively for almost all detected isomers. Total CLAs showed the highest values at the beginning of the grazing season and in autumn in coincidence with plant regrowth. CONCLUSION: These results show that even at low levels, supplement types can significantly influence the concentration of some CLA isomers in milk fat; an indication is given of the possibility tomanipulate the animals’ diet to change the CLA isomeric profile in ruminant-derived products.

Influence of low-level supplementation of grazing dairy cows with cereals or sugar beet pulp on the concentrations of CLA isomers in milk

RENNA, Manuela;
2010-01-01

Abstract

BACKGROUND: A wide range of isomer-specific health benefits have been attributed to conjugated linoleic acids (CLAs). Little information is currently available on the influence of different feed components on the concentration of CLA isomers in ruminant-derived products. The aims of this study were to compare the effect of cereal mix or dried sugar beet pulp supplementations fed to grazing dairy cows on milk CLA isomeric distribution and to examine the monthly variation of CLA isomers during the grazing season. RESULTS: The concentrations of the isomers t7c9, t10c12 and t10t12 were higher in milk from cows supplemented with cereals (P ≤ 0.001). The milk of beet pulp-supplemented cows showed higher levels of the isomers t11c13 (P ≤ 0.05), t9t11 (P ≤ 0.001) and t7t9 (P ≤ 0.01). Total CLA as well as seven other minor isomers were not significantly affected by the concentrate type. Monthly variations occurred extensively for almost all detected isomers. Total CLAs showed the highest values at the beginning of the grazing season and in autumn in coincidence with plant regrowth. CONCLUSION: These results show that even at low levels, supplement types can significantly influence the concentration of some CLA isomers in milk fat; an indication is given of the possibility tomanipulate the animals’ diet to change the CLA isomeric profile in ruminant-derived products.
2010
90
1256
1267
http://onlinelibrary.wiley.com/doi/10.1002/jsfa.3968/abstract;jsessionid=324E7BB65D83D1115CFBA9C74B27F127.d03t04
bovine milk; conjugated linoleic acids; pasture; cereal mix; beet pulp
Manuela Renna; Marius Collomb; Andreas Munger; Ueli Wyss
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/134920
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 7
  • ???jsp.display-item.citation.isi??? 8
social impact