Effect Of Selenium Source On Growth Performance, Physiological And Biological Indices And Muscle Quality Of Lingnan Yellow Broilers

This study was conducted with Lingnan yellow broilers to evaluated Na2SeO3 and Se-Met source at four dietary Se levels on broiler growth performance physiological and biological indices and meat quality.In this experiment,Se was added to dietary by 0.15,0.30,0.45,0.60mg/kg respectively. During the experiment feeding and butcher trial were done.Experiment 1.A total of 270 1-d old Lingnan yellow broilers were allotted to 9 treatments at random after they were fed for one week. Every treatment had 3 replicates with 8 broilers each replicate. Diets were formulated including 4 Se levels mentioned above. The broilers were fed according to 3 phases ,that is,8-28 day-old ,28-49 day-old and 49-70 day-old. The results were as follows: There was no obvious effect of different levels of Se on feed intake of 28 day-old broilers (P>0.05).And there was more obvious effect on body weight and feed conversion rate for broilers .Body weight of broilers was the highest when broilers were fed diet included Se level of 0.6 mg/kg ,compared with broilers in other treatments which included lower level of Se(P<0.05).There was the contrary trend in feed weight ratio .There was obvious effect on feed and weight ratio for 49 day-old broilers(P<0.05).And there was some effect on feed intake and body weight during this period. Feed intake and body weight was the highest when broilers were fed diet included Se level of 0.6 mg/kg , compared with broilers in other treatments which included lower Se level (P<0.05).There was no obvious effect of different levels of Se on body weight of 70 day-old broilers (P>0.05).And there was more obvious effect on feed intake and feed and weight ratio for broilers .Feed intake of broilers was the highest when broilers were fed diet included Se level of 0.60 mg/kg ,compared with broilers in other treatments which included lower Se level (P<0.05).There was the contrary trend in feed weight ratio .There was increased effect of different levels of Se on Se retaining percentage of Lingnan yellow broilers , and Se retaining percentage was stable when broilers were fed diet included Se level of 0.45 mg/kg .There was more obvious effect of organic selenium on broilers than inorganic , and the effect was the most obvious when broilers were fed diet included Se level of 0.60 mg/kg .Experiment 2.This experiment had the same treatment as the first one . And the results were showed as follows: All the immune organs index of Lingnan yellow broilers were increased by different Se levels . And with increasing level of Se in diets , immune organs index had a tendency to be improved . Organic selenium had more obvious effect than inorganic selenium . Of those , immune organs index was the highest when Se added in diet was 0.60 mg/kg , compared with broilers in other treatments which included lower Se level (P<0.05).Serum enzyme activity of broilers aged 28 , 49 and 70 days was improved with increasing level of Se in diet . Of those , organic selenium Se-Met had more obvious effect than inorganic selenium . Enzyme activity was the highest when level of Se added in diet was 0.60 mg/kg ,compared with broilers in other treatments which included lower Se level (P<0.05).The content of selenium in tissues of 28,49 and 70 day-old was improved with increasing level of Se in diet .And organic selenium Se-Met had more obvious effect than inorganic selenium . Of those , the content of selenium in tissues was highest when broilers were fed diet included Se level of 0.60 mg/kg ,compared with broilers in other treatments which included lower Se level (P<0.05).Experiment 3.This experiment had the same treatment as the first one . And the main results were as follows: There was no obvious effect of different levels of Se on muscle fiber diameter of 28 , 49 and 70 day-old broilers (P>0.05).And drop loss of 28 and 49 day-old broilers had the same effect. But there was depressed effect on drop loss of 70 day-old broilers . PH and MDA of 28 , 49 and 70 day-old were influenced by levels of different Se source .Of those , organic selenium had more obvious effect than inorganic selenium .PH of broilers was the highest ,and drop loss , MDA of broilers was the lowest When level of Se added in diet was 0.60 mg/kg , compared with broilers in other treatments which included lower Se level .