Effect Of Montmorillonite On Production Performance, Blood Metabolism And Apparent Digestibility Of Nutrients In Lactation Holstein Dairy Cows

This study was conduct to evaluate the effect of different concentration ofmontmorillonite on dry matter intake, production performance, digestibility andrelated safety parameters in mid lactation dairy cows, in order to give the appropriatedosage of feed.75multiparous healthy Holstein dairy cows (DIM=181d, parity=2.2)were blocked by DIM and parity and then randomly assigned to five treatments (15per treatment) in an8-wk trial. Cows were exposed to TMR diets supplements with0,0.5,1,2.5and5%montmorillonite respectively.1Effect of dietary supplementation of montmorillonite on dry matter intake andproduction performanceThe DMI was significantly lower of cows given5%montmorillonite incomparision to the control group, as well as milk production had a lower trend. Cowsgiven1%montmorillonite had a higher protein percentage in milk (P<0.05), and therewas a higher trend of milk fat percentage, fat yield and protein yield. But in contrast,fat yield and4%fat correct milk had a lower trend.2Effect of dietary supplementation of montmorillonite on blood parameters ofdairy cowsMontmorillonite in the diet did not significantly affect white blood cell count,RBC count, hematocrit, hemoglobin, platelet count, glutamic acid amino shift enzyme,aspartic acid amino shift enzyme, total protein, albumin, globulin, alkalinephosphatase, urea nitrogen, cholesterol, triglyceride and blood sodium, chloride,magnesium ions in comparision to those not receiving bentonite in diet. But0.5%and1%montmorillonite in the diet significantly improved concentration of copper ions,zinc ions and calcium ions. In addition,2.5%and5%montmorillonite in the diet hadno significant influence of zinc ions, calcium ions, magnesium ions and iron ions. But,1%montmorillonite in the diet significantly improved the concentration of potassiumion in the blood. There was no significant influence of vitamin A and vitamin E, buthigh dose of montmorillonite in the diet (5%) had a trend to reduce the content ofvitamin in blood. 3Effect of dietary supplementation of montmorillonite on the apparent nutrientsdigestion rate of dairy cowsThe addition of0.5%or1%montmorillonite to rations of dairy cows did notinfluence the digestion rate of protein, NDF, ADF and organic matter. But high dose(2.5%,5%) of montmorillonite would significantly reduce the digestion rate ofnutriment (P<0.01).0.5%montmorillonite in the diet did not influence the digestionrate of dry matter, but it would significantly reduced as the montmorillonite increased.Montmorillonite supplementation with diets had no significant influence of thedigestion rate of fat, but there was a tendendy for montmorillonite to reduce thedigestion rate of fat as the montmorillonite increased in the diet (P=0.49). In addition,2.5%and5%montmorillonite in the diet had a negative influence in the digestion rateof nutrients.4Effect of dietary supplementation of montmorillonite on the aflatoxin M1inmilk of dairy cowsMontmorillonite in the diet significantly reduce aflatoxin M1in milk of dairycows, in addition, aflatoxin M1residue in the milk reduced with the montmorilloniteincreased.