Effect Of Micro-Ecological Agent-BLCS On Ruminal Fermentation And Milk Performance And Nutrient Digestibility In Lactating Cows

This experiment was conducted to study the effects of Micro-Ecological Agent---BLCS on rumen fermentation and milk performance and digestive function and immune function of dairy cows through in vivo ruminal fermentation text, feeding trial,experiment of microbial cultivation and digestion experiments to provide theoretical basis for application of BLCS in diet of dairy cows.Thesis consists of five trails. Trail 1 divided into 3 treament groups (Control, 2.5g BLCS group, 5g BLCS group) was used a 3×3 Latin square design. Three treatment groups were fed 0g, 2.5g and 5g BLCS per day to determine rumen fermentation parameters after feeding 2h,4h,8h,12h,24h.Based on trail 1, twenty-four holstein cows with similar parity,lactation period, milk yield and body weight were divided into two equal groups ,BLCS group and control group,each had 12 cows.The BLCS group was supplied with 5g BLCS per day and the control group without added BLCS. The duration lasted 90d after 10d pre-trial period.Topics discussed through milk performance, serum biochemical, immunological indicators , the number of micro-organisms in hindgut and nutrient digestibility.The results showed that:1. Significant decrease in NH3-N concentration and increases of BCP,TVFA,Acetate and Propionate concenstrations indicated a positive influence on rumen fermentation of 5g BLCS.2. The supplementation of 5g BLCS could significantly increased milk yield and production of milk composition.The milk yield increased about 9.83%.3. Feeding 5g BLCS could reduce the amout of E.coli of post intestine and obviously improve the digestibility of OM, DM and CP, and NDF digestibility also tend to be increased.4. BLCS could improve digestive function. Cows in 5g BLCS group was higher in TPand TG in serum , and the concenstration of BUN was decreased, which showed that it had a improved effect in protein utilization and metabolism.5. BLCS could promote immune function.The concenstrations of IgG and IgM were significantly increased in 5g BLCS group, and SCC was markedly lowered .