| As people pay more attention to the food safety and environmental protection, more and more attentions have been paid to the acidification agent. At present, the main application of acidification agent in weaning piglets, and the application study on laying hens did not mature in weaned piglets.So the action mechanism and the effect of adding the acid agent still need to be discussed. This paper discussed the two parts of the acidification agent, Firstly, the composite acidification agent was screened to determine the ratio of each acid compound, then it was used to study the action mechanism of the acidification agent in the production of layers. The two tests were as follows:Text1:Screening of in vitro complex acidification:In this project, the test used the uniform test with two kinds of complex acidifier type. The first compound acidification agent was a lactic acid compound agent, which was denoted as Al type compound. The second compound acidification agent was phosphoric acid compound agent, which was denoted as A2 type compound. Each type of acidification designed seven different ratio. The optimal proportion of compound acid was obtained by the regression equation of the pH, the daily grain, the buffer capacity, the inhibitory diameter of the Escherichia coli and the inhibitory diameter of the Golden Grape. Test results showed that:The result indicated it had optimum effects When lactic acid, citric acid, fumaric acid and malic acid accounted respectively for 30%、8%、14% and 12% in lactic acid type acid. The result indicated it had optimum effects When lactic acid, citric acid, fumaric acid and malic acid accounted respectively for 30%、8%、 14% and 12% in phosphoric acid type.Text2:Effects of compound acid on performance, egg quality, nutrient metabolic rate and blood biochemical indexes of laying hens:(1)In terms of production performance:Compared with the blank control group, the egg laying rate of E group was 7.99%(P<0.05), which was significantly increased by third weeks. The egg laying rate of G group was significantly increased by third and fourth week, respectively 8.50% and 10.16%(P<0.05). The egg laying rate of H group was significantly increased by second, third or fourth and fifth weeks (P<0.05), respectively 12.60%、10.87%、10.33% and 10.87%(P<0.05). The average egg weight of E group was 5%, which was significantly increased at third weeks(P< 0.05). E, G group significantly reduced the egg ratio of third weeks, respectively 11.33%(P<0.01)、10.93%(P<0.05). H group significantly reduced the egg ratio of second weeks to 8.78%(P<0.05). Experimental group (C-H) compared with the control group, the control group were not significant difference.(2) In egg quality:Compared with the blank control group, D, E, B, G, H group eggshell thickness were increased to 2.94%,5.88%,5.88%,5.88%,5.88%(P<0.05). The E group significantly increased the HA units to 3.09%(P<0.05). Experimental group (C-H) on eggshell strength, egg weight and egg shape index had no significant difference (P>0.05). Compared with the control group, experimental group (C-H) had no significant difference in eggshell strength, egg shape index, eggshell thickness, egg weight and egg weight (P>0.05).(3) In terms of nutrient digestibility:Compared with the control group, the experimental group (C-H) significantly improved the apparent digestibility of crude protein (P<0.05), D, E, F, G group significantly improved the apparent digestibility of calcium was 7.75%,8.30%,7.40%(P<0.05) and 11.39%(P<0.01). E group significantly improved the apparent digestibility of phosphorus was 12.31%(P<0.05). Compared with the blank control group, the apparent digestibility of crude fat and dry matter in experimental group (C-H) was not significant (P>0.05). E, G, H group compared with the control group, apparent digestibility of crude protein was significantly different (P<0.05). Other groups had no significant difference compared with the control group (P>0.05).(4)In terms of blood biochemical parameters:Compared with the control group, E、G group significantly increased the content of total protein, albumin and globulin (P<0.05). E group significantly decreased the contents of uric acid and urea (P< 0.05), significantly increased the content of alkaline phosphatase (P<0.01). G group significantly increased serum calcium content was 17.70%(P<0.05). Experimental group (C-H) compared with the blank control group was not significant (P<0.05). Experimental group (C-H) compared with the control group, the serum protein significantly difference (P<0.05). The differences of serum uric acid, urea, alkaline phosphatase, calcium and phosphorus were not significant (P>0.05).To sum up, in the diet of laying hens, adding 0.3% lactic acid type and 0.2% phosphoric acid type compound, the effect was better in the actual production. |
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