Study On Breeding Hybridization And Growth Performance,Physiological Characteristics In Its Offspring Of The Bullfrog

In order to explore the problem of bullfrog germplasm degradation and improve the quality of bullfrog,this paper takes the local bullfrog and American bullfrog as the research object,and studies the reproductive characteristics and the characteristics of growth,digestion,immunity and muscular nutrition of the offspring by cross breeding.The Studies were showed that:1.The different breeding strategies of bullfrogThe rate of oxytocin in 4 groups were American Bullfrog Group(84%)>Orthogonal Group(76%)>Backcross Group(72%)>Local Bullfrog Group(68%);the hatching rate was shown in the American Bullfrog Group(86.35%)>Orthogonal Group(84.20%)>Backcross Group(81.50%)>Local Bullfrog Group(80.26%);the emergence rate were American Bullfrog Group(84.82%)>Orthogonal Group(82.70%)>Backcross Group(80.60%)>Local Bullfrog Group(77.53%).The survival rate of the Orthogonal Group and the Backcross Group after hatching to3cm and the tadpoles abnormal rates were better than those of the other two groups,which showed that the Orthogonal Group was optimized and better than the Backcross Group in the reproductive characteristics.2.The growth characteristics of progenyThe body length and weight growth of Bullfrog offspring in the 4 groups in large water environment(72m~2)and small water environment(20m~2)were studied,respectively,the results were showed the body length and weight growth of the Orthogonal Groups were 12.56±0.50cm、26±60.16g and 53±0.72cm、20±51.05g,respectively which were significant differences with the Local Bullfrog Group(P<0.05).Growth rates in large water environment and small water environment,the length and weight gain rate showed that the Orthogonal Group was higher than the other three groups,318.67±16.74%and 10283.02±1879.87%respectively,and there was no significant difference between the American Bullfrog Group and the Backcross Group(P>0.05),however,there was significant difference with the Local Bullfrog Group(P<0.05).The specific growth rate and specific growth(increase)rate in large water environment and small water environment were showed:the Orthogonal Group leads the other three groups,which were0.681±0.19%,2.203±0.091%and 0.6801±0.0277%,2.225±0.076%,respectively.There were significant differences with the Local Bullfrog Group(P<0.05).There was no significant difference in the full degree of the 4 groups in the large water environment and the small water environment(P>0.05).The aquaculture benefit of small water is better than that of large water environment.3.The digestive enzyme activity of liver and intestine in offspringThe activity of liver digestive enzymes in offspring showed that:the American Bullfrog Group was higher than the other three groups in protease activity,there were significant differences with the other three groups(P<0.05);In amylase activity,the Backcross Group and the Orthogonal Group were the leading group,but there was no significant difference between the groups(P>0.05);In the lipase activity,the Orthogonal Group was higher than that of the other three groups.There were significant differences with the other three groups(P<0.05).The activity of digestive enzymes in offspring was showed that:the Orthogonal Group was in the leading position,and there was significant difference with the American Bullfrog Group(P<0.05).The activity of digestive enzymes in different digestive organs of Offspring was significant difference(P<0.05),protease and amylaseactivity showed intestines>liver;lipase activity showed liver>intestines.4.The progeny immune related indices of offspringThe activity of T-AOC,LZM,GR and GSH-Px in the serum immune-related indicators in the subgeneration of the Backcross Group was the best,while the other immune-related enzymes were relatively high.In enzymes of Lzm,GR vigor,there was no significant difference(P>0.05)between the Backcross Group and the American Bullfrog Group,the Local Bullfrog Group,expect there was significant difference with the Orthogonal Group(P<0.05);The activity of AKP,protein concentration,ACP and POD in the serum of the Orthogonal Group was higher than that of the other three groups,and which were significantly different from the other three groups(P<0.05).5.The nutritional characteristics of offspring muscleThere were significant differences in the water content of 4 groups of Bullfrog Offspring(P<0.05);the protein content of the Orthogonal Group,the Backcross Group and the American Bullfrog Group,the Local Bullfrog Group has the remarkable difference(P<0.05),the fat content of the Orthogonal Group and the Backcross Group were lower than the American Bullfrog Group,the Local Bullfrog Group;the ash content of four groups had no significant difference(P>0.05);the Orthogonal Group,the Backcross Group,the American Bullfrog Group and the Local Bullfrog Group,The ratio of a flavor amino acid/total amino acids(FAA/TAA)were 32.42±0.81%,32.78±0.44%,31.89±0.42%and 31.86±0.43%respectively.The fatty acids of muscle had level palmitic acid and oleic acid.The above results showed that the breeding method of bullfrog was superior to self breeding in breeding,growth performance and physiological characteristics.The Orthogonal Group had higher reproductive performance,such as induction rate,emergence rate,survival rate and metamorphosis rate,and the Orthogonal Group was superior to the Backcross Group in growth performance and digestive characteristics.In terms of immune and muscular nutritional characteristics,the reciprocal group was superior to the Orthogonal group.