Effects Of Feeding Lutein On Lactation Performance And Milk Quality Of Dairy Cows

Lutein, an anti-oxidative nutrient, is a natural carotenoid widely found in vegetables, flowers,fruits and certain algae species. It is demonstrated that feeding lutein could enhance animalperformance, and improve the animal reproductive performance, and improve the quality of eggs.Lutein is also widely used in functional food. The objective of this study was to determine theeffects of lutein on milk production and milk quality of lactation dairy cows.Currently, lutein was mainly determined by high performance liquid chromatography(HPLC). In this study, a simple, fast and reliable method has been developed for the determinationof lutein content in milk. Milk samples were saponified, protease hydrolyzed and extracted byn-hexane, then separated and determined by chromatographic column. A normal phase silica gelcolumn was used with a mixture of n-hexane: ethyl acetate: isopropanol=65:30:5as mobile phaseand UV detection at446nm. The recovery of added lutein was94.8%~96.3%, and the RSD was0.7%, which indicated that the method has good accuracy and precision. The content of lutein wasfound to be0.51~0.62μg/100mL in milk by this method.An experiment was conducted to determine the influences of different levels of lutein in dieton the production performance, plasma metabolites and milk quality of Chinese Holstein lactatingcows. Sixty multiparous Holstein dairy cows were selected in peak lactation period and randomlyallocated to one of four homogeneous treatments fed, with lutein additive (AbsoLUTEIN,extracted from Marigold, its effective content was2%) at levels of0,100,150, or200g/d,accordingly, the actual available lutein at levels of0,2,3, or4g/d, respectively. The experimentlasted for13week with the first week for adaptation to the diet. Milk yield and milk compositionswere recorded weekly, and milk concentrations of lutein, dry matter intake, and blood index wereanalyzed in the first, fourth, seventh, and thirteenth week of the study. The results showed that thelutein in diet had no effect on DMI compared with the control group (P>0.05). Feeding of luteincan slow down the trend of decline of milk yield, and has a significant increment effect on milkyield with the supplement of4g lutein/d (P<0.05). Dietary lutein tended to increase thepercentage of milk fat (P=0.07), and significantly increased milk lactose with the highest value for4g of lutein/d (P<0.05), and decreased somatic cell count with the lowest value for3g and4gof lutein/d. Concentration of lutein in milk linearly increased with supplementation of lutein indiets (P<0.05), with the value0.59,0.70,1.20, or1.50μg/100mL for treatments with0,2,3, or4g of lutein/d in diet, respectively. Plasma total antioxidant capacity tended to linearly increase incows fed lutein (P=0.07), whereas plasma superoxide dismutase and glutathione peroxidaseactivity showed no significant changes with the feeding of lutein, which indicated that feeding oflutein could enhance the antioxidant capacity of cows. It is inferred that the dietary addition of3~4g lutein/d is beneficial for lactation dairy cattle to improve milk performance and milkquality.