| Probiotics can promote the host micro ecological balance, to improve the level of the host’s health and health status has an important role. Probiotics mainly come from the animal intestinal normal physiological bacteria and intestinal bacteria. At present, the existing variety of probiotics has been widely applied in animal husbandry, such as lactobacillus and bifidobacterium, bacillus, yeast class, etc., in actual production application of probiotic preparations for the single more probiotics or a mixture of probiotic strains. Yeast is a kind of unicellular eukaryotes, is a kind of commonly used eukaryotic model organisms, has the important function of lactic acid. Due to a variety of questions with antibiotics, in 2006 the eu started to ban si with antibiotics, spurred the search for green, safe and efficient feed additive as a substitute for a kind of probiotics, yeast and its culture for green, natural, non-toxic and harmless, no residue, etc, has become a research hotspot.Candida rugosa, old called Candida cylindracea, is a kind of half ascus spore, false filaments, single, not pathogenic yeast. Usually think c. rugosa to humans and other life forms are safe without side effects, its for fat catabolism have a certain role in promoting. C. rugosa was not fixed live strains of chicken intestine, so wild C. rugosa strains could not colonize the chicken intestines stranded for a long time or, play a good effect. Mutation breeding is a method by using the physical and chemical factors to induce mutation, genetic traits of plants and animals that make change, then select one of mutation groups to meet the requirements of the expected some kind of individuals and strains, so as to cultivate new varieties of breeding method. It is developed after selective breeding and cross breeding of a modern breeding technology. This study through ultraviolet mutagenesis C. Rugosa and extend the selection method of combining the chicken, screening to the retention of mutations in a chicken intestines for a long time, promote the growth of the chicks. This research mainly for the following:Part I: Uv mutagenesis screening of Candida rugosa:By changing the vertical irradiation of ultraviolet(UV)(15, 20, 25 cm), irradiation time(0.5, 1, 1.5 min) to mutation strains, selected 41 ℃ during slab YPD 5 strains of good growth. Fill it take 3 weeks of highland, brown laying hens, pick out the retention time of a set of CRZL to 18, the chicken body extend the selection, finally obtained the retention time is 34 is a mutant strains CRZL h- 26, using morphological identification and gene sequencing, the sequence alignment coincidence rate were greater than 99%, identified as Candida rugosa: from the molecular level. Part Ⅲ:Chicks age for Candida rugosa in chicken intestines were strandedPart Ⅱ:the chicks for Candida rugosa in chicken intestines stranded day ageBy filling and take highland brown laying hens CRZL- 14 / CRZL- 18 / CRZL- 26 found that chicks day age affect c. Rugosa in chicken intestines, retention time, with the increase of chicks day age, c. Rugosa in gradually extend the residence time of chicken intestine, compared with CRZL- 18 strains of CRZL- 26 strains in chicks first can keep better retention properties.PartⅢ:C. Rugosa’s influence on the highland brown laying hens weight change :Pick out 1 age of 30 healthy weight close to highland brown laying hens, randomly divided into 3 groups, control group(Con), CRZL14 experimental Ⅰ and CRZL28 experimental Ⅱ, statistics two weeks of feed intake and body weight. Experimental way can increase the body weight, the experimental group Ⅱ is more significant, no significant effect on feed intake. |
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