Study On Solid-state Fermentation Condition Of Concentrate And Its Application On Dairy Cattle

In this research, the fermentation condition of solid-state fermented concentrate were optimized, and nutritional quality of fermented concentrate were determined, then the effects of replacing concentrate with fermented concentrate on milk yield, milk somatic cell count and fecal morphology for dairy cattle were further studied. There were three parts in this studyExp.1:Optimization of processing conditions for mixed bacterial solid-state fermentated dairy concentrateAn experiment was conducted to explore a new strategy of co-inoculation Bacillus subtilis CGMCC1.0892 and Saccharomyces cerevisiae CGMCC2.119 as starter culture to produce fermented dairy concentrate. Effects of inoculation proportion,inoculum level, sodium humate and wheet bran supplementary,initial moisture content, incubation duration, fermentation temperature on the nutritional quality of the fermented product were investigated. The optimal processing conditions of fermented dairy concentrate were: Bacillus subtilis to Saccharomyces cerevisiae ratio,3:7;sodium humate supplementary in the starter culture and fermentation substrate,2%;wheet bran supplementary,5%; inoculum level,2.5%; initial moisture content,50%; Incubation duration,48h; fermentation temperature,34℃.Exp.2:Analysis of nutritional quality of fermented dairy concentrate with Bacillus subtilis and Saccharomyces cerevisiaeThe research was conducted to determine the nutrition value of fermented concentrate and raw material. The results showed that:Compared to raw materials, crude protein (20.38%), true protein (19.94%), calcium (1.12%), and phosphorus (0.74%) content was significantly increased (P<0.05). Ether extract (1.39%), crude fiber (6.89%), neutral detergent fiber (18.29%), and acid detergent fiber (14.08%) in the fermented concentrate was significantly reduced (P<0.05). There was no significant difference in crude ash conte ent (P>0.05).The neutral protease, cellulase, and amylase content was significantly higher than raw materials (P< 0.05), it was 4.68 times,3.39 times, and 4.62 times greater than raw material, respectively. After fermentation,the polysaccharide (9.45mg/g), reducing sugar (2.74%), soluble sugar (19.53%) and soluble protein (2.43%) was also significantly enhanced (P< 0.05). The total amino acid content of the fermented dairy concentrate was 17.95mg/100mg,it was 1.07 times than raw material.At the same time, the number of viable Bacillus subtilis and Saccharomyces cerevisiae in fermented concentrate was 4.80×109cfu/g, and 4.96×108cfu/g.Exp.3:Effects of replacing concentrate with fermented concentrate on milk yield, somatic cell count and fecal morphology for dairy cattleA total of 20 Holstein dairy cattle with the same age, parity, performance month, daily milk yield were randomly divided into 2 groups. Dairy cattle was fed either a control diet with basic concentrate or a test diet with 5% fermented concentrate add at expense of con centrate. The experiment lasted 60 d.The average daily milk production of the treatment group (22.40kg) was higher than the control group (20.50kg) (P<0.05).Total milk yield (10023.40kg) was significantly higher than that in control group (9512.58kg) (P<0.05). The somatic cell count of treatment group determined at 25 and 50 d (27.54 and 24.60×104 /ml)was lower than control group (39.98and 40.46×104/ml) (P<0.01). The feces were observed in the experimental group, which was significantly better than the control group (P<0.05).