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Effects of calcium propionate supplementation on lactation performance and metabolites in early lactEffects of calcium propionate supplementation on lactation performance and metabolites in early lactation Holstein dairy cowsThirty-two multiparous Holstein dairy cows,blocked by lactation number,corrected milk yield in last lactation,and expected calving date,were designated into four treatments in a randomized block experiment.The additive levels(0,100,200,and 300 g/d) of calcium propionate were graded in the four treatments.The results showed that average feed intake,milk fat percentage,milk protein percentage,milk lactose percentage and milk dry matter percentage were not affected significantly by calcium propionate supplementation(P>0.05).Milk yield and feed efficiency of cows supplemented calcium propionate at 200 g/d and 300 g/d were higher than those of cows supplemented calcium propionate at 100 g/d and fed control diet significantly(P<0.05).Concentrations of glucose and insulin in plasma of cows supplemented calcium propionate at 200 g/d and 300 g/d were higher than those cows fed control diet significantly(P<0.05).Concentrations of non-esterified fatty acids and β-hydroxybutyrate in plasma of cows supplemented calcium propionate at 200 g/d and 300 g/d were lower than of cows fed control diet significantly (P<0.05).Concentrations of urine ketones of cows supplemented calcium propionate at 200 g/d and 300 g/d were lower than that of cows supplemented calcium propionate at 100 g/d and fed control diet significantly(P<0.05).These results indicated that the optimal dose of was 200 g/d calcium propionate supplementation.
CHINESE JOURNAL OF VETERINARY SCIENCE 2009.29(10) |