【作者】 林长光；

【导师】 郑金贵；

【作者基本信息】 福建农林大学 ， 持续发展与推广学， 2013， 博士

【摘要】 硒是人和动物的必需微量元素,缺乏会严重影响健康。我国约72%国土面积的土壤缺硒,靠天然食品来补充硒无法满足人和动物对硒的需求。猪肉占居民肉类消费比例63%以上,富硒猪肉的研发对人体补硒具有十分重要的意义。本论文研究了不同硒源和硒水平对不同阶段猪的生产性能和免疫功能、抗氧化等保健功能的影响,以及对血浆和母乳中硒含量的影响,研究了硒在猪不同组织中的沉积效果,筛选出硒源和硒水平的最佳组合,建立了富硒猪肉生产的关键技术体系,为开发优质富硒猪肉奠定了良好的基础。主要结果如下：一、不同硒源和硒水平对猪生产性能和保健功能的影响1、不同硒源和硒水平对猪生产性能的影响哺乳仔猪：酵母硒0.3,0.5mg·kg-1硒水平组和纳米硒0.5,0.7mg·kg-1硒水平组,仔猪初生窝重分别比对照组提高了16.13%,23.88%,25.98%,29.70%(P<0.05)。饲粮硒水平为0.5mg·kg-1酵母硒组仔猪断奶窝重、窝增重、平均日增重与对照组相比,分别提高了38.44%、42.96%和17.07%(P<0.05)。断奶仔猪：硒水平为0.3,0.5mg·kg-1的纳米硒组和硒水平为0.5mg·kg-1酵母硒组日增重分别比对照组提高了7.26%,9.46%和13.07%(P<0.05)。酵母硒0.3,0.5mg·kg-1硒水平组和纳米硒各硒水平组的平均料重比均显著低于对照组和0.7mg·kg-1亚硒酸钠组(P<0.05)。育肥猪：纳米硒组的日增重显著高于酵母硒组(P<0.05),极显著高于对照组和亚硒酸钠组(P<0.01)；添加硒各组育肥猪料重比极显著低于对照组(P<0.01),酵母硒组极显著低于纳米硒组和亚硒酸钠组。以上结果表明：酵母硒和纳米硒提升猪生产性能的效果均显著优于亚硒酸钠。0.5mg·kg-1硒水平的酵母硒和纳米硒均显著提高了初生仔猪、断奶仔猪和生长育肥猪的日增重,并显著降低了料重比(P<0.05)。2、不同硒源和硒水平对猪甲状腺激素水平的影响哺乳母猪和哺乳仔猪：硒源、硒水平、硒源和硒水平的交互作用对哺乳母猪和哺乳仔猪血清T3、T4含量的影响极显著(P<0.01)。纳米硒组母猪血清T3水平分别比对照组、亚硒酸钠组和酵母硒组提高了29.52%、17.24%和23.63%(P<0.01)；纳米硒组母猪血清T4含量分别比对照组、亚硒酸钠组和酵母硒组降低了24.71%、30.88%和33.86%(P<0.01)。亚硒酸钠组、纳米硒组和酵母硒组哺乳仔猪血清的T3水平分别比对照组提高12.82%、26.50%和20.51%(P<0.01);不同硒源分析,亚硒酸钠组和纳米硒组哺乳仔猪血清T4含量分别较对照组降低了18.39%和26.51%(P<0.01)。断奶仔猪:0.5,0.7mg·kg-1硒水平的纳米硒组仔猪血清的T3含量均极显著高于对照组和亚硒酸钠各组(P<0.01);T4含量随着硒水平的升高而降低,但纳米硒组与对照组相比差异不显著(P>0.05)。育肥猪：0.5,0.7mg·kg-1硒水平的纳米硒组育肥猪血清T3含量显著高于对照组(P<0.05),其中0.5mg·kg-1硒水平组与对照组差异极显著(P<0.01)。以上结果表明：纳米硒有效提高了哺乳母猪、断奶仔猪、育肥猪的血清T3含量,特别是0.5mg·kg-1硒水平的纳米硒组效果最佳。3、不同硒源和硒水平对猪免疫功能的影响哺乳母猪和哺乳仔猪：纳米硒组母猪血清IgA含量分别比亚硒酸钠组、酵母硒组提高了142.64%,35.29%(P<0.01),IgM含量分别比亚硒酸钠组、酵母硒组提高了63.83%、8.51%(P<0.01)。与对照组相比,亚硒酸钠、纳米硒和酵母硒组哺乳仔猪血清IgG含量分别提高了19.11%,43.39%,34.63%(P<0.01)；IgA含量分别提高了93.67%,160.75%,132.91%(P<0.01)；IgM含量分别提高了90.91%,140.91%,102.27%(P<0.01)断奶仔猪和育肥猪：纳米硒和酵母硒组断奶仔猪和育肥猪血清中IgA、IgG、IgM含量显著高于对照组和亚硒酸钠组(P<0.05)：其中纳米硒组与对照组相比,育肥猪的血清中IgG、IgA、IgM含量分别提高了9.24%、13.36%和9.24%(P<0.01)以上结果表明：酵母硒和纳米硒能有效提高哺乳母猪、断奶仔猪和育肥猪血清中IgG、IgA、IgM的含量。其中纳米硒的效果显著优于酵母硒和亚硒酸钠,纳米硒0.3-0.7mg·kgq添加量均可显著提高猪的免疫功能。4、不同硒源和硒水平对猪抗氧化能力的影响从硒源分析,纳米硒组和酵母硒组哺乳母猪、断奶仔猪和育肥猪的GSH-Px活性与对照组相比显著提高(P<0.05)：纳米硒组断奶仔猪和育肥猪的T-AOC含量与对照组相比,分别提高了13.40%和10.51%(P<0.05)；纳米硒组育肥猪MDA含量分别低于对照组、亚硒酸钠组和酵母硒组8.20%、6.67%和6.25%(P<0.05)。结果表明：纳米硒组对试验猪抗氧化能力的提高效果显著。5、不同硒源和硒水平对猪血浆、母乳中硒含量的影响添加硒可显著提高母乳中的硒含量(P<0.05),纳米硒组和酵母硒组的母猪血浆、母乳中硒含量高于亚硒酸钠组;0.5,0.7mg·kg-1硒水平的纳米硒组和酵母硒组与对照组相比,哺乳母猪、哺乳仔猪及育肥猪血浆中硒含量差异显著(P<0.05)。结果表明：0.5,0.7mg·kg-1硒水平的纳米硒组和酵母硒组对血浆和母乳中硒含量的提高效果显著。6、提升猪生产性能和保健功能的硒源和硒水平最佳组合提升猪生产性能和保健功能的硒源和硒水平最佳组合：哺乳母猪饲粮硒水平为0.5mg·kg-1的酵母硒：断奶仔猪饲粮硒水平为0.5mg·kg-1的纳米硒或酵母硒：育肥猪饲粮硒水平为0.5-0.7mg·kg-1的纳米硒或酵母硒。二、富硒猪肉生产关键技术的研究1、不同硒源和硒水平对猪胴体性状与肉质的影响饲粮中添加硒对于育肥猪的胴体性状的改善无明显作用；纳米硒组和酵母硒组中猪肉的大理石纹和肉色比值显著优于亚硒酸钠组(P<0.05)；0.5mg·kg-1硒水平的纳米硒组和酵母硒组猪肉的大理石纹比值与对照组相比,分别提高12.5%和15.63%(P<0.05);0.7mg·kg-1硒水平纳米硒组肉色比值与对照组相比,提高了11.11%(P<0.05)。酵母硒和纳米硒可明显提高试验猪宰后45min和24h的pH值。硒水平为0.7mg·kg-1的纳米硒组和酵母硒组宰后45min内肉的pH值显著高于对照组(P<0.05)；纳米硒组中,0.3,0.5mg·kg-1硒水平组宰后24h肉的pH值均显著高于对照组及亚硒酸钠各硒水平组(P<0.05)。不同硒源组的滴水损失率大小为纳米硒组<酵母硒组<亚硒酸钠组<对照组,纳米硒组、酵母硒组和亚硒酸钠组比对照组分别下降了33.18%、23.02%和4.48%(P<0.01)。以上结果表明：纳米硒和酵母硒在改善肉色、pH值、滴水损失等猪肉品质方面表现出比亚硒酸钠更好的营养生物学作用。2、硒在猪不同组织中沉积效果的研究硒在不同组织中的沉积量从高到低依次为肾脏>肝脏>肌肉。纳米硒组中0.5mg·kg-1硒水平组的肾脏、肝脏、背最长肌、后腿肌肉组织中硒含量分别为2.61mg·kg-1、0.58mg·kg-1、0.29mg·kg-1、0.27mg·kg-1、0.7mg·kg-1硒水平组分别为2.90mg·kg-1、0.67mg·kg-1、0.34mg·kg-1、0.33mg·kg-1酵母硒组中0.5mg·kg-1硒水平组的肾脏、肝脏、背最长肌、后腿肌肉组织中硒含量分别为2.77mg·kg-1、0.59mg·kg-1、0.28mg·kg-1、0.28mg·kg-1;0.7mg·kg-1硒水平组分别为2.97mg·kg-1、0.65mg·kg-1、0.29mg·kg-1、0.27mg·kg-1。3、富硒猪肉生产关键技术体系的建立以生产富硒猪肉为目的,以猪肉无公害为标准,确定了育肥猪饲粮中硒源和硒水平的最佳组合：在120日龄生长育肥猪至出栏阶段,饲粮中添加纳米硒至0.7mg·kg-1硒水平。围绕富硒猪肉的整个生产系统,开展了生猪饲养、屠宰、分割、检疫检验和鲜肉贮存销售等重要环节的关键技术研究,建立了富硒猪肉生产的关键技术体系。以上研究结果表明：硒水平为0.7mg·kg-1的纳米硒在背最长肌和后腿肉中的硒沉积量分别达到0.34mg·kg-1和0.33mg·kg-1显著高于其他硒源和硒水平,比普通猪肉高2.4倍和2.3倍,实现了富硒猪肉生产的目标。更多还原

【Abstract】 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.更多还原