Effect Of Protein Level And Anion Additive On Peripartuient Cows

Experiments were conducted at 1.40M cal/kg DM, with the ratio of concentrate to roughage approximate 30:70,to investigate the effects of different dietary CP levels (14.0%, 12.1% and 9.6%) on periparturient Hostein cows (especially 3 weeks prepartum). Mo9090reover, anion balance technique was used to study the effects of adding anion additive into the diet. The result shows as follows:1. Dry matter intake (DMI) and the apparent digestibility of DM, CP, ADF, NDF,Ca and P are not affected significantly by different dietary CP levels; There is a decreasing tendency of placenta drainage interval with higher CP levels, but is insignificant. The milk yield within 60 days postpartum, milk fat percentage, milk solid, physical and chemical characteristics of milk are not affected apparently by different dietary CP levels; There is an increasing tendency of milk protein percentage with higher dietary CP levels, but is insignificant.2. When adding anion additive into the diet, the following phenomena areobserved: the acid-base balance changes to a slightly acidosis state (with pH around 6.5), and the PTH concentration increases apparently by a series of adjustment mechanisms. The blood calcium concentration at postpartum period is significantly higher than that of control group. What's more, no disadvantageous effect on liver function is found. The incidences of retained placenta and clinical hypocalcemia decrease when adding anion additive into the diet. There is no milk fever case in experiment group, but there is one in control group in contrast. The milk yield within 60 days increases significantly (p<0.05) when adding anion additive hi the diet.