| Diarrhea is a common disease in modern pig farm which causes significant economic losses every year.There are many different factors that can cause diarrhea.Research has shown that Enterotoxigenic Escherichia coli F4ac and F18 are important pathogens that induce diarrhea of piglets.The major genes which control piglets' susceptibility to diarrhea are MUC13 gene and FUTI gene.This study was designed to explore the diarrhea phenomenon,polymorphisms of MUC13 and FUT1 gene and gene frequency of anti-diarrhea in Suhuai pig and its anti-diarrhea selective breeding schemes based on MUC13 and FUT1 gene.The major conclusions are as follows:(1)Diarrhea phenotype observation and analysis in Suhuai pigletsThe lactation of Suhuai pig is 40 days.The diarrhea of 501 piglets from 53 litters was observed,and the results showed that the diarrhea rate was 4.79%in the 1st week,4.79%in the 2nd week,6.39%in the 3rd week,3.79%in the 4th week,0.80%in the 5th week,and 0.60%in the 6th week.The diarrhea rate was highest in the 3rd week,and then decreased gradually.The total diarrhea frequency of Suhuai piglets was 1.12%.The diarrhea frequency was 1.45%in the 1st week,1.45%in the 2nd week,2.20%in the 3rd week,0.83%in the 4th week,0.34%in the 5th week,and 0.16%in the 6th week.The diarrhea frequency was highest in the 3rd week,and then decreased slowly.The diarrhea originating rate of Suhuai piglets was 22.64%in the 1st week,22.64%in the 2nd week,30.19%in the 3rd week,17.92%in the 4th week,3.77%in the 5th week,and 2.83%in the 6th week.The diarrhea originating rate was highest in the 3rd week,and then decreased gradually.Compared weekly diarrhea rate,weekly diarrhea frequency and diarrhea originating rate between male and female Suhuai piglets,there are no significant difference in weekly diarrhea frequence,weekly diarrhea rate and diarrhea originating rate between male and female Suhuai piglets.By weighing the birth weight and weaning weight of Suhuai piglets,the effect of diarrhea on weaning weight was analyzed.The results showed that there was no significant difference in weaning weight between healthy piglets and diarrheal piglets.(2)Polymorphism analysis of anti-diarrhea genes MUC13 and FUTI in Suhuai pig and its selective breeding scheme on anti-diarrhea traitsThe results based on polymorphism analysis of anti-diarrhea genes MUC13 and FUT1 in 355 Suhuai pigs showed that the frequency of G allele in MUC13 gene was high that the boars reached 0.625 and the sows 0.568,which is conducive to improve the breeding of anti-diarrhea performance in Suhuai pig.In the genotype,the frequency of anti-diarrhea GG genotype was 0.500 in the boars,0.311 in the sows,0.315 in the whole population.Overall,frequency of the G allele which is resistance to pre-weaning diarrhea is higher than that of the A allele which is sensitive to pre-weaning diarrhea in Suhuai pig.It is conductive to improve the resistance to pre-weaning diarrhea in Suhuai pig,by eliminating AA genotype homozygous susceptible individuals,and matching insusceptible GG genotype individuals.In the core group of Suhuai pigs,frequency of the A allele in FUTI gene was low that boars reached.0.230 and the sows 0.190.In the genotype,frequency of the anti-diarrhea AA genotype was 0.125 in the boars,0.015 in the sows,0.018 in the whole population.This increases the difficulty,and takes a long period of time to breed the pigs resistance to weaned diarrhea induced by F18 in Suhuai pig.The combined genotypes of MUC13 gene and FUTI gene was also analyzed in this study.There were only 2 individuals in sows with the anti-diarrhea GGAA genotype.This suggested that the selection of both MUC13 gene and FUTI gene in the same time was difficult.In the actual production,we can give priority to the selection of MUC13 gene. |
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