关键词: 肉桂醛, 生长性能, 腹泻, 瘤胃发酵, 奶牛公犊

Abstract:

【Objective】this study was conducted to research effects of addition of cinnamaldehyde in calf starter on growth performance, health status, rumen fermentation and microflora of calves, so as to provide theoretical basis for applying cinnamaldehyde in calf cultivation. 【Method】Twenty-four healthy Holstein male calves at the age of around 15 days, with similar body weight, were selected, and were divided into control group and experiment group, with three replicates in each group and four calve in each replicate. The control group were fed basic starter, while starter of experimental group was added with 0.3% encapsulated cinnamaldehyde which contained 15% effective cinnamaldehyde. The weaning period contained 6 pre-trail period, and 27 days of formal trail period, both groups were fed same amount of milk, the starter and orts grass were given at libtium, and the ruminal fluid was taken by stomach tube at the end of weaning period. After weaned, the animals were kept for another 51 days with same feeding management mode, the ruminal fluid was taken at the end of the experiment. The feed intake, growth performance, body measurement, fence score and ruminal volatile fatty acids concentrations were measured during the two phase of the experiment, and the ruminal bacterial community composition was measured based on 16SrDNA gene high through put sequencing. 【Result】The results showed that: (1) In terms of feed intake and growth performance, there were no difference in average daily gain, dry matter intake and feed efficiency between experiment and control group at pre-weaning, post-weaning stage and whole experiment period (P>0.05), there were no differences in body measurements parameters between experiment and control group as well (P>0.05); 2) In terms of calf health status, the diarrhea rate of the experimental group was lower than that of the control group, but was not significant (P>0.05). 3) For the rumen fermentation parameters, the concentration of volatile fatty acids of rumen fluid in the experimental group on weaning day was tend to lower than that in the control group (P>0.05). At the end of the experiment, the concentration of volatile fatty acids, including acetate, propionate, butyrate and valerate of experimental group was significantly higher, while acetate/propionate ratio lower than that of control group (P<0.01); 4) At the end of experiment, cinnamaldehyde supplementation increased ruminal bacteria Shannon diversity index, decreased Simpson diversity index; addition of cinnamaldehyde increased abundance of Firmicutes and Actinobacteria at phylum and prevotella at genus level (P<0.01). 【Conclusion】The results showed that addition of 0.3% encapsulated cinnamaldehyde which contained 15% effective cinnamaldehyde had no influence on growth performance, but decreased diarrhea rate, increased ruminal volatile fatty acids concentration and decreased acetate/propionate ratio, increased ruminal bacterial community diversity, and abundance of Firmicutes and Prevotella, indicated addition of high amount of cinnamaldehyde had no adverse effects on calf growth performance, but changed ruminal bacterial community composition and ruminal fermentation mode.

Key words: cinnamaldehyde, growth performance, diarrhea, rumen fermentation, dairy calves