Suplementação com lecitina de soja na dieta de vacas leiteiras e seu efeito na produção, composição do leite e parâmetros sanguíneos

Abstract

Soy lecithin is a product rich in ethereal extract and contains fatty acids (FA) and phospholipids. The inclusion of soy lecithin in the diet of dairy cows can offer nutritional and metabolic benefits, including the lipid regulation and liver metabolism, as well as a positive influence on milk production and composition. Therefore, the aim of this study was to evaluate the effect of different levels of soy lecithin in the diet of dairy cows and its potential on milk production and composition, dry matter intake (DMI) and blood parameters. Three levels of dietary lecithin inclusion were evaluated for a total of four treatments: 0% lecithin (control diet); 0.75%; 1.5% and 2.2% soy lecithin in the dry matter (DM) of the diet. The cows were distributed in a 4x4 double latin square experimental design, using eight Holstein cows. For

the blood tests, blood samples were taken and the levels of albumin, total cholesterol, high- density lipoprotein (HDL), low-density lipoprotein (LDL), β-hydroxybutyrate (BHB),

triglycerides, hematocrits, total plasma protein (TPP), gamma-glutamyltransferase (GGT), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were analyzed. Logistic regression analysis was carried out to compare the treatments. Soy lecithin supplementation had no influence on DMI, but NDF intake (NDFI) showed a quadratic behavior (P<0.05), while ethereal extract intake (EEI) showed an increasing linear behavior (P<0.05) in response to supplementation. When analyzing milk composition, the inclusion of lecithin had a quadratic effect on protein concentration (P<0.05) and a linear effect on de novo fatty acid concentration (P<0.05). Higher levels of de novo FA in milk were found with the inclusion of lecithin, but milk fat levels were low, with an inversion being observed in the fat/protein ratio. The reduction in blood levels of PPT with lipid supplementation was significant, but not sufficient to suggest that this compound acts to attenuate inflammation, corroborating the results found in CCS levels. In general, the inclusion of soy lecithin did not cause changes in production, milk composition and blood parameters of lactating cows.