Effects Of Rumen-Protected Choline Supplementation On Milk Performance And Blood Metabolic Parameters In Holstein Cows

Thirty five healthy Holstein cows 10 days before parturition were fed basal diet(corn-silage based), basal diet with 5g/d choline choloride, 10g/d choline choloride, 10g/d RPC(Rumen-protected choline chloride), 20g/d RPC respectively to investigate the impact of rumen-protected choline choloride and unprotected choline choloride on milk yield, milk composition and some Serum biochemical parameters. The result showed, at DIM35 (days in milk 35) 4% FCM(fat corrected milk) of 10g/d RPC cows were 16.7% higher than 10g/d choline choloride cows, at DIM 35 4% FCM of 20g/d RPC cows were higher than controlled cows, 5g/d choline choloride cows, 10g/d choline choloride cows: 4.58, 3.99, 4.91 kg/d(p<0.05). Milk protein and total milk protein yield of 20g/d RPC cows were higher than those other groups cows in milk days, especially at DIM25(p<0.05).D-3-Hydroxybutyrate of 10g/d RPC or 20g/d RPC cows were lower than the other groups in the experiment period. At 5 time points: 24 houre after parturition, after parturition 1 week, 2 week, 3 week, 4 week, the diffrence was significant (p<0.05). At the same time, plasma glucose of 20g/d RPC cows was higher than those other 4 groups.During the experiment total cholesterol and HDL-C(High-density lipoprotein cholesterol) of 20g/d RPC cows were lower than those other three groups(p>0.05). There were no signifencant difference among 5 groups about milk glucose, milk ash, milk water and ALT (Alanine aminotransferase), AST(Aspartate aminotransferase) in the serum.20g/d RPC group earned much more money than the other 4 groups after this experiment.Overall, cows fed RPC produced more milk and milk protein than those other cows, RPC can help cows to raise plasma glucose in the first week after parturition and lower serum D-3-Hydroxybutyrate.