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.
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.
de Andrade
Patricia Vilhena Dias
PV
Unité Mixte de Recherches, Physiologie de la Nutrition et Alimentation, Département des Sciences Animales, Institut National Agronomique, Paris-Grignon, 75231 Paris Cedex 05, France.
Schmidely
Philippe
P
D000821:Animal Feed; D000818:Animals; D005227:Fatty Acids / Q000032:analysis*; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage; D005260:Female; D006041:Goats / Q000378:metabolism* / Q000502:physiology; D007263:Infusions, Parenteral; D007774:Lactation / Q000378:metabolism; D044243:Linoleic Acids, Conjugated / Q000008:administration & dosage / Q000494:pharmacology*; D008892:Milk / Q000737:chemistry* / Q000378:metabolism*; D011897:Random Allocation; D000074262:Rapeseed Oil
D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D044243:Linoleic Acids, Conjugated; D000074262:Rapeseed Oil