The Effect Of Selenium On Swine Production And The Health And The Key Technology Of Selenium-rich Pork Production

Selenium (Se) is the essential trace element for human beings and animals. Se Deficiency results in a severe health problem.72%land area in China is deficient in Se. Se intake through eating natural foods by peoples can not meet their body needs. To supplement Se by eating se-enriched pork is one of the best approaches. Pork accounts for63%total meat consumption by peoples and thereby it is very promising market to develop Se-enriched pork product.The objectives of this study were to investigate the effects of different sources and supplemental dosages of selenium on the pigs performance, immunity function n antioxidant capacity; Se concentration in milk, plasma and tissue, optimize sources and dietary supplemental dosage of selenium and establish key technical systems to produce Se-enriched pork with good quality.The results are shown as follows:1、he effects of different Se sources and dosages on the pigs performance and health functions(1)The effects of different Se sources and dosages on the pigs performanceSucking Piglets:Compared to those in control group, litter weight at birth of sows fed diets supplemented with Selenium yeast at0.3and0.5mg·kg-1and Nano-Selenium at0.5and0.7mg·kg-1significantly(P<0.05) increased by16.13%,23.88%and25.98%and29.70%, respectively. The weaning weight, litter weight gains and average daily weight gain (ADWG) of pigs fed on diets with the supplementation of Selenium Yeast at the0.5mg·kg-1significantly (P<0.05) increased by38.44%,42.96%and17.07%, respectively.Weaned piglets:Compared to those in control group, daily weight gains of pigs fed on diets supplemented with Nano Selenium at0.3and0.5mg·kg-1and Selenium yeast at0.5mg·kg-1significantly(P<0.05) increased by7.26%,9.46%and3.07%, respectively.The FCR values of pigs fed diets supplemented with Selenium yeast at0.3and0.5mg·kg-1, and the Nano Selenium at different supplemental dosage diet were significantly(P<0.05) lower than those in the control group and those pigs fed the0.7mg·kg-1sodium selenite supplemental diet.Fattening pigs:The daily weight gain of G/F pigs fed the Nano-selenium diet are significantly higher (P<0.05) than those in the Selenium Yeast, were extremely significantly (P <0.01) higher than those in control and Sodium Selenite group. The Feed/gain of G/F pigs supplemented with three sources of Se was extremely significantly(P<0.01) lower than those in the control group. The Feed/gain of G/F pigs supplemented with Se yeast was extremely significantly(P<0.01) lower than those in the Nano-Selenium and Sodium Selenite group.The results have demonstrated that:The performance of pigs supplemented with Se yeast and Nano-Seleniuim was higher than those in the Sodium Selenite group.The pigs fed diets supplemented with the Selenium Yeast and Nano-selenium at level of0.5mg·kg-1significantly(P <0.05) improved the average daily gains of piglets during lactation, weaning and G/F pigs, and significantly lower the feed/gain value (P<0.05).(2) The effects of different Se sources and levels on the serum thyroid hormonesLactation sows and sucking piglets:The effect of different sources and levels of Selenium, and the interaction effect between Se sources and levels on T3and T4concentrations of lactation sows and sucking piglets were extremely significant (P<0.01). The serum T3concentration of sows fed diets supplemented with Nano-selenium group were significantly(P<0.01) increased by29.52%,17.24%and23.63%, respectively compared to those in the control, sodium selenite and selenium yeast, and the serum T4content of sows fed diets supplemented with the Nano-selenium group were significantly(P<0.01) decreased by24.71%,30.88%and33.86%respectively.Compared to those in control group, the serum T3contents of sows fed the Sodium Selenite, Nano-selenium and Yeast Selenium groups were significantly (P<0.01) increased by12.82%%26.50%and20.51%,respectively, The serum T4contents of sows fed the Sodium Selenite and Nano-selenium supplemental diets were significantly (P<0.01) decreased by18.39%and26.51%,respectively.Weaned piglets:The serum T3contents of piglets fed diets supplemented with Nano-selenium at0.5and0.7mg·kg-1was significantly (P<0.01) higher than those in the control and Sodium Selenite groups; while serum T4content was decreased with the increased levels of Se in the diets and there are no significant (P>0.05)differences between the Nano-selenium and control group in terms of the serum T4concentration.Fattening pigs:The serum T3contents of fattening pigs fed diets supplemented with the Nano-selenium at0.5and0.7mg·kg-1was significantly(p<0.05) higher and the serum T3levels of pigs fed diets supplemented with Se at0.5mg·kg-1are significantly higher (P<0.01) compared to those in the control group.The results have demonstrated that:Dietary supplementation of the Nano-selenium can increase the serum T3contents of sows, weaned piglets and fattening pigs. The optimal dosage is at the Nano-Selenium at0.5mg·kg-1Se.(3) The effect of different sources and dosages of selenium on the immunity status of pigs Lactation sows and sucking piglets:compared to those in the Sodium Selenite and Selenium Yeast groups, the serum IgA concentration of sows fed the Nano-selenium diets increased by142.64%,35.29%, respectively, while there was a significant (P<0.01)increase for the serum IgM concentration by63.83%,8.51%, respectively.Compared to those in the control group, the serum IgG concentration of sucking piglets fed the sodium selenite, Nano-selenium and Selenium yeast was significantly (P<0.01) increased by19.11%,43.39%and34.63%, respectively, while there was a significant (P<0.01)increase for the serum IgA concentration by93.67%.160.75%and132.91%, respectively and by90.91%.140.91%,102.27%,respetively for the serum IgM concentration.Weaned piglets and fattening pig:the serum IgA, IgG and IgM of weaned piglets and fattening pigs fed the Nano-selenium and Selenium Yeast diet were significantly higher (P<0.05)than those in the control and Sodium Selenite group. Compared to those in the control group, the serum IgA, IgG and IgM concentrations of fattening pig supplemented with the Nano-selenium diets significantly (P<0.01) increased by9.24%,13.36%and9.24%, respectively.The results have demonstrated that:Dietary supplementation of Selenium Yeast and Nano-selenium can increase the serum IgA, IgG and IgM of sows, weaned piglets and fattening pigs. The effect of dietary supplementation of the Nano-selenium is better than those in the Selenium Yeast and Sodium Selenite group. Dietary supplementation of the Nano-selenium at the levels from0.3-0.7mg·kg-1can significantly improve pig immunity function.(4) The effects of different sources and dosages of antioxidant capacity status in pigsBased on the analysis on Se sources, the GSH-Px activity status of lactating sows, weaned piglets and fattening pigs fed the diets with Nano-selenium and Selenium Yeast were significantly (P<0.05) increased and the T-AOC concentration of weaned piglets and fattening pigs fed diet with the Nano-selenium increased (P<0.05) by13.40%and10.51%, respectively compared those in the control group. The MDA content of fattening pigs fed the Nano-selenium were decreased (P<0.05) by8.20%、6.67%and6.25%, respectively than those in the control, Sodium Selenite and Selenium Yeast groups. These results have demonstrated that Nano-selenium can improve antioxidant capacity in pigs.(5) The effect of different sources and dosages of selenium on the concentration of plasma Se and Se in sows milkDifferent Se sources have significant(P<0.05) effects on the Se concentration of sow milk: Se contents in plasma and in milk of sows fed the Nano-selenium and Selenium Yeast diets were higher than those in the Sodium Selenite group; Compared to those in the control group, plasma Se contents of lactation sows, sucking piglets and fattening pigs fed the Nano-selenium and Selenium Yeast diets at the0.5and0.7mg·kg-1Se were significantly(P<0.05) higher. These results have demonstrated that dietary supplementation of the Nano-selenium and Selenium Yeast at the dosages of0.5and0.7mg·kg-1Se can significantly improve the Se contents in plasma and milk of pigs.(6) Optimization of the Se sources and dosages for the performance and functionsThe recommendation combination of Se sources and dosages based on the performance and functional parameters are yeast Selenium at0.5mg/kg Se for lactation sows; Nano-selenium or Selenium Yeast at0.5mg·kg-1Se for weaned piglets and Nano-selenium or Selenium Yeast at Se0.5or0.7mg·kg-1Se for the fattening pigs.2Establish key technical systems to produce Se-enriched pork(1)The effects of different Se sources and dosages on the carcass characteristics and meat quality in pigsDietary Se supplementation has no effect on the carcass characteristics in fattening pigs.Marbling port and color value of pigs fed the Nano-selenium and Selenium Yeast diets are better than those in the Sodium Selenite.Compared to those in the control group, Marbling pork and color value of pigs fed the Nano-selenium and Selenium yeast diets at the0.5mg·kg-1Se improved(P<0.05) by12.5%and15.63%, respectively, while color value of pigs fed the Nano-selenium at the0.7mg·kg-1Se improved(P<0.05) by11.1%.Dietary supplementation of the Selenium yeast and Nano-selenium can significantly increase the pH value at45min and24h after slaughter. Compared to those in the control group, pH values of pork at45min after slaughter from the pigs fed the dietary addition of the Nano-selenium and Selenium Yeast at0.7mg-kg’1Se is significantly(P<0.05) higher. pH values of pork at24h after slaughter from pigs fed the Nano-selenium at0.3and0.5mg·kg-1Se are significantly(P<0.05) higher than those in the control and Sodium Selenite groups.Different Se sources in each group drip loss in order are Nano-selenium<yeast selenium <sodium selenite<control. Compared to those in the control group.drip loss of pigs fed the Nano-Selenium and selenium yeast diets decreased(P<0.05) by33.18%、23.02%and4.48%, respectively.These results have demonstrated that the Nano-selenium and yeast Selenium has better nutritional and biological function than the Sodium Selenite in improving meat color, pH value and decrease in drip loss.(2) The deposition of Se in different tissuesSelenium in different tissues in the order of deposition are kidney> liver> muscle. The Se contents in kidney, liver, longissimus dorsi and back-leg muscle of pigs fed the Nano-selenium diet supplemented with0.5mg·kg-1Se are2.61,0.58,0.29and0.27mg·kg-1respectively. while the Se contents are2.90,0.67,0.34and0.33mg·kg-1, respectively when the dietary Se supplementation at0.7mg·kg-1.The Se contents in kidney, liver, longissimus dorsi and back-leg muscle of pigs fed diets with the supplementation of Selenium yeast at dosages of0.5mg·kg-1Se are2.77,0.59,0.28,0.28mg·kg-1,respectively. while the Se contents are2.97,0.65,0.29and0.27mg·kg-1, respectively when the dietary Se supplementation at0.7mg·kg-1.(3) Establish key technical systems to produce Se-enriched porkThe objective of this study was to produce Se-enriched pork using the green, safe production system and standard, the sources and levels of Selenium were optimized and established for fattening pigs:Using Nano-selenium at dietary supplementation of0.5-0.7mg/kg Se. In the mean time, key production systems including pigs feeding, slaughter, meat storage and marketing have been developed.This study indicates that Se contents in longissimus dorsi and muscle of back-leg from Nano-selenium with Se0.7mg·kg-1are0.34and0.33mg·kg-1significantly higher the other sources and dosage,compared with common pork,Se contents increased by2.4times and2.3times. This meets the standard of Se-enrich pork.