Reprod. Nutr. Dev. 46 (2006) 19-29
DOI: 10.1051/rnd:2005058

Effect of a supplement rich in linolenic acid added to the diet of post partum dairy cows on ovarian follicle growth, and milk and plasma fatty acid compositions

Andrew A. Ponter^a, Anne-Emmanuelle Parsy^a, Marion Saadé^b, Jean-Paul Mialot^a, Christine Ficheux^a, Christine Duvaux-Ponter^c and Bénédicte Grimard<sup>a

a</sup>  UMR INRA-ENVA 1198, Biologie du Développement et Reproduction, 7 avenue du Général-de-Gaulle, 94704 Maisons-Alfort, France
^b  Ferme Expérimentale, Institut National Agronomique Paris-Grignon, 78850 Thivernal-Grignon, France
^c  UMR INRA-INA P-G, Physiologie de la Nutrition et Alimentation, 16 rue Claude Bernard, 75231 Paris Cedex 05, France

(Received 20 December 2004; accepted 11 June 2005; published online 27 January 2006)

Abstract - The objective of this study was to determine the effect of a linseed supplement on follicle growth, progesterone concentrations and milk and plasma fatty acids in dairy cows post partum. Sixteen Holstein cows were given a basal total mixed diet plus one of two supplements: control (C; extruded soybeans; n = 8) or linseed (L; extruded linseeds; n = 8). One month after calving oestrous cycles were synchronised (PRID^®). Follicle growth and milk progesterone concentrations were measured every 2 d over the induced oestrous cycle. Milk production characteristics were unaffected by treatment. The L cows lost significantly more BCS than the C cows (P < 0.01). Plasma insulin, glucose and urea were unaffected by the treatment. Plasma NEFA tended to be affected by the treatment (L > C, P = 0.08). The proportions of 18:3n-3 in milk and plasma were increased by L compared to C (P < 0.001 and P < 0.01, respectively). There was an effect of dietary supplement on the numbers of small follicles (L < C, P < 0.05). Milk progesterone was unaffected by treatment. In conclusion, the increased supply of 18:3n-3 to the cows had only a modest effect on follicle populations and corpus luteum activity was unchanged.

Key words: linolenic acid / milk and plasma fatty acids / follicle growth / dairy cows

Corresponding author: Andrew A. Ponter ponter@vet-alfort.fr

© INRA, EDP Sciences 2006