| In order to solve the shortage of conventional feed in China and meet the needs of the booming animal husbandry,in recent years,many researchers have turned their attention to the development of new types of unconventional feed research.Because of the lower price and many biological active ingredients of jujube meal,it has naturally become a research hotspot.In this experiment,the effects of different levels of jujube meal on rumen fermentation,apparent digestibility,blood indexes and milk production performance of dairy cows were studied by in vitro fermentation test and cow feeding test,so as to provide scientific data for the rational and effective application of jujube meal in ruminants.Experiment 1: in this study,the effects of different levels of jujube meal on the fermentation parameters of gastric juice in vitro were studied.Menke method was used to produce gas in vitro.Different levels of jujube meal were added into the feed,with five different gradients of 0%,5%,10%,15% and20%,respectively.Gastric juice was collected from 3 Holstein cow before morning feeding,and the experiment was conducted in vitro fermentation.3 replicates were set for each group and each time period,and the gastric juice was fermented for 3,6,9,12,24,48 and 72 h,respectively.The results showed that: 1)in vitro fermentation of different levels of jujube meal,the gas production increased with the extension of time,from 9 h to 48 h,the gas production showed a significant secondary increase with the increase of the level of jujube meal(Q;P < 0.05).2)in the first 3 h,with the increase of jujube meal level,NH3-N concentration decreases linearly(L;P < 0.05);propionic acid and propionic acid showed an upward trend(P < 0.1).Correspondingly,the ratio of propionic acid to acetic acid decreased with the increase of jujube meal level(P < 0.1).3)the radical scavenging rates of GSH-Px,SOD,T-AOC and DPPH in gastric juice were significantly increased after the addition of jujube meal(P < 0.05).4)the dry matter(DM)degradation rate of each jujube meal level group increased with the time regularity,reaching the maximum value at 72 h,close to 100%;At 3 h,with the increase of jujube meal level,the digestibility of CP presented a significant linear increase(L;P < 0.05),the maximum value was reached in the 20% jujube meal group.At 6 h,it was consistent with the trend of 3 h at first,but at 15% jujube meal group,the curvewas quadratic and reached a significant difference(Q;P < 0.05).Experiment 2: the purpose of this experiment was to study the effect of jujube meal in TMR on rumen fermentation and milk production performance of dairy cows.Twenty healthy holstein female cows were randomly divided into two groups: the control group(0% jujube meal)and the experimental group(10%jujube meal).The test period was 10 weeks,in which the first 2 weeks were the pre-test period and the remaining 8 weeks were the positive test period.1)the addition of jujube meal reduced the concentration of NH3-N in the rumen(P < 0.1),and the total VFA concentration increased significantly,but the molar ratios of VFA did not change significantly.2)the antioxidant activity of gastric tumor fluid was enhanced,DPPH clearance rate was significantly increased(P < 0.05),and other indicators showed a certain trend(P< 0.1).3)the digestibility of OM was significantly increased(P < 0.05),while the digestibility of DM and CP was increased(P < 0.1).4)jujube meal can significantly improve DMI and milk yield(P < 0.05),the milk fat rate also showed an increasing trend(P < 0.1),the total antioxidant capacity of emulsion,SOD,DPPH clearance rate significantly increased,the number of body cells also significantly decreased.The results showed that jujube meal,which accounted for 12% of the dry matter of the diet,was used in the diet of lactating cows. |
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