Reprod. Nutr. Dev. 46 (2006) 31-48
DOI: 10.1051/rnd:2005062

Effect of duodenal infusion of trans10,cis12-CLA on milk performance and milk fatty acid profile in dairy goats fed high or low concentrate diet in combination with rolled canola seed

Patricia Vilhena Dias de Andrade and Philippe Schmidely

Unité Mixte de Recherches "Physiologie de la Nutrition et Alimentation", Département des Sciences Animales, Institut National Agronomique, Paris-Grignon, 75231 Paris Cedex 05, France

(Received 30 March 2005; accepted 12 July 2005; published online 27 January 2006)

Abstract - The effect of t10,c12-C18:2 on milk production, and fatty acid (FA) profile of milk fat was studied in 8 goats infused duodenally with t10,c12-C18:2 (2 g·10 h^-1) during 3 days, followed by a 2-day infusion of skim milk (SM). The goats were assigned to 4 diets in a factorial arrangement constituted by low (L = 45%) or high (H = 65% of the diet DM) percentage of concentrate without (CS0) or with (CS20) rolled canola seed (20% of the concentrate DM). Milk samples were collected before (basal), and during the t10,c12-C18:2 and SM infusions. The t10,c12-C18:2 in milk fat increased from undetectable basal values to an average of 0.39% of total FA in the 3rd day of t10,c12-C18:2 infusion. DMI, milk yield, and the contents and yield of milk fat, protein, and lactose were similar between basal and the t10,c12-C18:2 infusion. The concentration of saturated FA with 4 to 16C did not change during the t10,c12-C18:2 infusion, whereas C18:0 increased, particularly in the milk fat of the CS20 group. The t10,c12-C18:2 infusion increased the t10- and t11-C18:1 (except a reduction in t11-C18:1 for the H-CS20 group), and it decreased the c9,t11-C18:2 in milk fat, particularly for the H-CS20 group. The t10,c12-C18:2 infusion reduced the c9,t11-C18:2/t11-C18:1 ratio, particularly for the CS0 group. The results indicate that mammary lipogenesis in dairy goats was not decreased by t10,c12-C18:2, however, the desaturation of long chain FA appeared to be equally affected as in dairy cows. This reduction in the desaturase index of milk fat could have been a direct effect of t10,c12-C18:2, or mediated via an increase in t10-C18:1.

Key words: milk fatty acids / t10,c12-C18:2 infusion / canola seed / goat

Corresponding author: Philippe Schmidely schmidel@inapg.inra.fr

© INRA, EDP Sciences 2006