tailieunhanh - Báo cáo thú y: "Scandinavica cung cấp cho các bạn kiến thức về bệnh thú yđề tài: Rumen-protected conjugated linoleic acid supplementation to dairy cows in late pregnancy and early lactation: effects on milk composition, milk yield, blood metabolites and gene expression in liver"

Tuyển tập các báo cáo nghiên cứu về bệnh học thý y được đăng trên tạp chí Acta Veterinaria Scandinavica cung cấp cho các bạn kiến thức về bệnh thú yđề tài: Rumen-protected conjugated linoleic acid supplementation to dairy cows in late pregnancy and early lactation: effects on milk composition, milk yield, blood metabolites and gene expression in liver. | Sigl et al. Acta Veterinaria Scandinavica 2010 52 16 http content 52 1 16 AVS ACTAVETERINARIA SCANDINAVICA RESEARCH Open Access Rumen-protected conjugated linoleic acid supplementation to dairy cows in late pregnancy and early lactation effects on milk composition milk yield blood metabolites and gene expression in liver Tanja Sigl1 Gregor Schlamberger1 Hermine Kienberger2 Steffi Wiedemann1 Heinrich HD Meyer1 Martin Kaske3 Abstract Background Conjugated linoleic acid CLA is a collective term for isomers of octadecadienoic acid with conjugated double-bond system. Thus it was the objective to investigate whether milk composition and metabolic key parameters are affected by adding CLA to the diet of dairy cows in the first four weeks of lactation. Methods A study was carried out with five primiparous cows fed a CLA supplemented diet compared to five primiparous cows without CLA supplementation. CLA supplemented cows received g CLA day . 50 cis c 9 trans t 11- and 50 t10 c12-CLA starting two weeks before expected calving and 20 g CLA day . 50 c9 t11-and 50 t10 c12-CLA throughout day 1 to 28 of lactation. Results The CLA supplement was insufficiently accepted by the animals only of the intended amount was ingested. Fed CLA were detectable in milk fat whereas contents of c9 t11-CLA and t10 c12-CLA in milk fat were higher for CLA supplemented cows compared to the control group. On average over the entire treatment period there was a decrease of saturated fatty acids FA in milk fat of CLA supplemented cows combined with a higher content of monounsaturated and trans FA. Our study revealed no significant effects of c9 t11- and t10 c12-CLA supplementation either on milk yield and composition or on metabolic key parameters in blood. Furthermore the experiment did not indicate significant effects of c9 t11- and t10 c12-CLA-supplementation on gene expression of peroxisome proliferator-activated receptor-alpha PPARa PPARg sterol regulatory .