| The high-quality development of layer industry plays an important role in agriculture and rural economy.Genetic breeding technology,diet nutrition technology,disease prevention and control technology,production environment technology and egg product processing technology of laying hens contribute to improving the production performance and egg quality of laying hens.Probiotics can improve animal immunity and promote the healthy growth of animals.The application of probiotics in laying hens industry is of positive significance.Lactobacillus salivarius has the functions of regulating intestinal flora,inhibiting the proliferation of harmful bacteria,slowing down intestinal inflammatory response,enhancing antioxidation and inhibiting tumor necrosis factor.This study studied the effect of Lactobacillus salivarius SNK-6 on laying hens through long-term feeding experiment,so as to provide theoretical and practical basis for the application of Lactobacillus salivarius SNK-6 in large-scale feeding of laying hens.This study was divided into four parts.The first three parts studied the effects of long-term feeding of Lactobacillus salivarius SNK-6 on the production performance,egg quality and eggshell surface microorganisms of hyline brown layers.It was found that feeding Lactobacillus salivarius could significantly improve the eggshell strength;In the fourth part,the factors affecting eggshell strength were studied to establish basic data for the study of the mechanism of Lactobacillus salivarius improving eggshell strength.1.Effects of long-term feeding of Lactobacillus salivarius SNK-6 on the performance of hyline brown layers.The indexes such as the number of dead eggs,qualified eggs,broken eggs,laying eggs,laying weight,feed consumption and drinking water were statistically analyzed.The results showed that compared with the control group,the main production performance indexes of laying hens in the experimental group were better than those in the control group,and the survival rate index had obvious advantages.The monthly stock mortality of laying hens in the experimental group decreased significantly in the first,third and tenth months of the experiment(P<0.05),and extremely significantly in the sixth and eighth months of the experiment(P<0.01).2.Effect of feeding Lactobacillus salivarius SNK-6 on the quality of hyline brown eggs.The eggshell strength,yolk color,albumen height,haugh unit,eggshell thickness and egg dark spots of eggs aged 34,38,42,46,50,54,58,60 and 64 weeks were detected.The results showed that feeding Lactobacillus salivarius SNK-6 could improve the quality of hyline brown eggs.Compared with the control group,the eggshell strength of 9 batches of eggs in the test group was significantly higher than that in the control group(P<0.01),which was 0.20 kg/cm~2higher than that in the control group.At 46 weeks of age,there was significant difference in haugh units(P<0.05).Feeding Lactobacillus salivarius SNK-6 improved egg dark spots.There was significant difference in the grade of dark spots between 34 and 58 weeks old(P<0.05).3.Effect of Lactobacillus salivarius SNK-6 on microorganisms on the surface of hyline brown egg shell.The results showed that the relative abundance of Proteobacteria on eggshell surface in the experimental group was significantly lower than that in the control group(P<0.05);The relative abundance of intestinal Salmonella in the experimental group decreased by 55%(P<0.01),the number of Romboutsia in the experimental group increased significantly(P<0.01),and the number of Kocuria increased significantly(P<0.05).4.Factors affecting eggshell strength.The eggs of 10 different week old hyline brown layers and 7 different week old Xinyang black feather layers were collected to detect the egg quality,determine the calcium content and organic matter content of hyline brown layers,and study the factors affecting the eggshell strength.With the change of week age,egg weight,haugh unit,eggshell thickness,yolk color and eggshell thickness had a very significant effect(P<0.01),and had a significant effect on albumen height(P<0.05).Haugh unit,eggshell weight index and eggshell thickness were positively correlated with eggshell strength,and eggshell strength was negatively correlated with eggshell density index.With the same eggshell thickness,the calcium content of low-strength eggshell is less than that of high-strength eggshell;Compared with the eggshell strength with high organic matter content in the eggshell,the eggshell strength with low organic matter content in the eggshell is higher.When the weight index of eggshell is the same,the calcium content in eggshell is directly proportional to the strength of eggshell;With the increase of organic matter content in eggshell,the strength of eggshell decreased.The content of organic matter in jingfen No.6 high-strength eggshell of jingfen No.6 laying hens and shendan No.6 laying hens at the same age was higher than that of shendan No.6 laying hens.This study provides a theoretical basis for long-term feeding of Lactobacillus salivarius SNK-6 to hyline brown layers to improve the production performance,improve the egg quality,reduce harmful bacteria on the surface of eggshell and improve the eggshell strength. |
