Effects Of Different Selenomethionine Forms On Productive Performance Of Breeder Hens

This research was conducted to investigate the effect of different selenomethionine (SM) sources and levels on the productive performance of breeder hens and to approach the mechanism by Se content and antioxidant system function of serum and tissue in the breeder hens and its offspring, secretion of related hormones and immune indexes of breeder hens'serum.A total of four hundred eighty Ling-Nan-Huang breeder hens,48 week of age, were allocated to four treatments, each of which included three replicates of 40 hens. A corn-soybean meal basal diet, the basal Se content of which was 0.04 mg/kg, was provided to the breeder hens. Two SM forms of DL-SM and L-SM, was supplemented at 0.15 or 0.30 Se mg/kg into the basal diet. Breeder hens had limited access to feed but ad libitum access to water. The feeding experiment lasted for 8 weeks after 2 weeks of adaptation period.Total egg numbers were collected and recorded for each replicate everyday and incubated once a week.5 eggs per replicate were collected at random and stored at 4℃until divided into egg yolk and egg white for analysis of Se content. At the end of the rearing experiment, four breeder hens and 15 chicks at 1-d-age of each replicate were slaughtered. Samples were collected after slaughter and analysed.The main results were as follows:1. The results of feeding experiment indicated that compared with the level of 0.30 mg/kg,0.15 mg/kg level significantly increased percentage of egg production (p<0.05),but the SM forms showed little effect on all performance indexes (p>0.05). In addition, Average egg weight, average feed daily intake and feed/egg ratio showed no significant difference among all four groups (p>0.05).2. The results of hatching experiment showed that 0.15 mg/kg level significant elevated hatchability and birthrate (p<0.05), however, all egg hatchability indexes were not affected by SM forms (p>0.05). The birthrate was affected by the interaction between SM form and Se level (p<0.05), and greatest in the L-SM group supplemented with 0.15 mg Se/kg.3. The results of egg quality showed that egg shape indexes were not affected by SM form and Se level (p>0.05), and DL-SM tended to increase HU comparing with L-SM.4. The results of chick slaughter experiment indicated that compared with DL-SM, L-SM significantly elevated the index of liver (p<0.05), but other organs were not affected by SM forms and Se levels at all (p>0.05).5. The results of Se content showed that both SM forms and Se levels significant affected the Se content in the breeder hens'serum and tissues (p<0.05), except pancreas, and its offspring'tissue (p<0.05), except liver and muscle, and the egg inclusion (p<0.05). In detail, the level of 0.30 mg Se /kg was superior to 0.15 mg Se /kg (p<0.05), and DL-SM was superior to L-SM (p<0.05). Furthermore, the interaction between SM form and Se level affected the Se content in yolk (p<0.05), which was highest in group DL-SM at the level of 0.30 mg Se /kg.6. The testing results of antioxidant system function revealed that:(1) Compared with L-SM, DL-SM significantly improved the GSH-Px activity of breeder hens'serum, GSH-Px and SOD activities of breeder hens and its offspring' liver and kidney (p<0.05), and decreased the MDA content in serum, liver and kidney of breeder hens (p<0.05).(2) For breeder hens, compared with the group of 0.30 mg Se/kg,0.15mg Se/kg significantly elevated the GSH-Px activity, GSH concentration and T-AOC level in serum and pancreas, the activity of GSH-Px and SOD in liver, the GSH concentration and T-AOC level in muscle, and T-AOC level in kidney (p<0.05), but decreased MDA content in muscle and kidney (p<0.05). For chickens,0.15mg Se/kg markedly improved the GSH-Px activity and T-AOC of kidney (p<0.05).(3) The GSH content in muscle and the GSH-Px activity and T-AOC level in serum were affected by the interaction between the SM forms and Se levels. And as to former, the group of L-SM at 0.15mg Se/kg was highest, but for the latter, the group of DL-SM at 0.15 mg Se/kg was greatest. 7. Results of hormone test showed that compared with 0.30 mg Se/kg, TT4 was reduced by 16.09% (p<0.05) and the ratio of TT3 to TT4 increased by 12.24% (p<0.05) in the group of 0.15 mg Se/kg, however, the SM form had litter effect on the secretion of hormone (p>0.05). Besides, the interaction between SM form and Se level affected the TT3/TT4 value (p<0.05), and the group of L-SM at the 0.15 mg Se/kg was greatest.8. Results of immune indexes test indicated that SM form and Se level were not affected all immune indexes (p>0.05).Above results suggest:In comparision with SM dose effect,0.30mgSe/kg was significant greater than 0.15mgSe/kg in tissue Se content, however,0.15 mgSe/kg was superior to 0.30 mgSe/kg in productive performance and antioxidant system function. Referred to SM form effect, DL-SM was equal with L-SM in the productive performance of breeder hens, but DL-SM was superior to L-SM in Se concentration and antioxidant function.