【作者】 陈军；

【导师】 赵茹茜；

【作者基本信息】 南京农业大学 ， 兽医， 2011， 博士

【摘要】 当前我国地方猪种的营养标准,几乎均参照国外标准制(修)定,而我国地方猪种的形成历史,体型结构,采食习惯均与外种猪有较大区别。另外,生产上饲料过多的蛋白质供应,往往导致粪便排N量增加,对环境造成污染。因此,国内地方猪种的合理的营养供应,成为当前研究的一个热点。梅山猪起源于太湖流域的浏河两岸,长期的自然生态环境和较低蛋白水平的日粮,造就了梅山猪耐粗饲、高产仔的特性。而随着集约化饲养方式的推广,梅山猪食物结构由原来青粗料为主变为现在的精饲料为主,其产仔数也随之出现下降的趋势。为了检验蛋白质水平对梅山母猪及其后代的影响,我们对妊娠、哺乳期梅山母猪进行不同蛋白水平日粮饲喂(妊娠期对照组母猪日粮粗蛋白含量12%,哺乳期粗蛋白含量14%,低蛋白组母猪日粮粗蛋白含量降低50%),同时检测仔猪不同阶段体重、器官重和肌肉组织重变化。为了进一步研究母猪妊娠、哺乳期不同蛋白水平对仔猪抗氧化水平的影响,我们检测了70胚龄仔猪胎盘组织的抗氧化酶活性和出生后仔猪不同生长发育阶段的血清抗氧化酶活性。这些研究能够探索梅山母猪合理的蛋白质营养水平,为梅山猪饲养管理和品种保护提供指导。1梅山母猪妊娠哺乳期日粮蛋白水平对母猪分娩、仔猪发育和经济效益的影响将24头纯种初产梅山母猪随机分为对照组(标准蛋白)和试验组(低蛋白)。标准蛋白组母猪在妊娠期给予粗蛋白含量为12%的日粮,试验组给予粗蛋白含量为6%的日粮。哺乳期对照组母猪日粮粗蛋白含量为14%,低蛋白组母猪日粮粗蛋白含量降低50%饲喂。对照组和低蛋白组妊娠期70胎龄时各屠宰4头母猪,取胎盘和胎猪称重；其余母猪继续饲养至产仔,并称量新生仔猪体重,测量新生仔猪体尺；所有仔猪由本母猪哺乳,不进行并窝代奶,两星期后开始使用相同教槽料,哺乳期间仔猪自由采食；哺乳期为35天,所有仔猪统一35日龄断奶,对断奶猪称重,记录断奶个体重；35日龄断奶后所有仔猪转入育肥舍,按原来分组进行并栏(即低蛋白组与低蛋白组并栏,标准蛋白组与标准蛋白组并栏)。育肥期两组后代猪日粮配方及营养成分相同。育肥仔猪饲养至184 d时,选择接近平均体重的育肥猪进行屠宰(对照组8头,试验组9头),记录个体重。结果显示,70胚龄胎猪重总体低蛋白组显著低于对照组(P<0.05),分性别统计雌性差异显著,雄性差异不显著；而两组胎盘重无论总体还是分性别统计两组差异均不显著(P>0.05)。试验组的妊娠天数与对照组无显著差异(P>0.05),总产程比对照组缩短了22.63%(P>0.05),平均产仔间隔缩短了28.96%(P>0.05)。对照组和试验组平均总产仔数分别为8.55和10.25,平均产活仔数分别为7.91和9.00,说明母猪低蛋白水平饲喂能提高产仔头数,但差异不显著(P>0.05)。试验组产活仔率比对照组低2.64%,但差异也不显著(P>0.05)。试验组平均初生窝重要比对照组低14.4%,但差异不显著(P>0.05)；初生个体重不分公母统计试验组比对照组低132.87g,差异显著(P<0.05)；分公母统计,其中雄性试验组比对照组低131.3g,差异极显著(P<0.01),雌性试验组比对照组低124.8g,差异也极显著(P<0.01)。试验组和对照组体高、体长、胸围无论总体或分性别统计差异均不显著(P>0.05)。试验组的断奶重比对照组低1983.89g,极显著低于对照组(P<0.01),说明低蛋白降低了断奶重。试验组的只均增重和日增重也极显著(P<0.01)低于对照组,可知降低蛋白水平对增重有影响。试验组与对照组育肥猪体重无显著性差异(P>0.05)。母猪妊娠、哺乳期低蛋白饲喂,对猪场经济效益的影响主要体现在母猪采食饲料成本的降低和低蛋白营养导致母猪产仔数增加产生的效益,以500头母猪计算,年增效益可达482591元。以上结果提示：梅山妊娠、哺乳期母猪饲喂低蛋白日粮使母猪产仔数和产活仔数增加,但会对胚胎发育和产奶水平有影响,而断奶仔猪解除低蛋白营养后对育肥猪体重无显著影响,说明低蛋白组存在着较强的补偿生长。从猪场经济效益和猪的整个发育角度考虑低蛋白是有利的。2梅山母猪妊娠哺乳期日粮蛋白水平对仔猪不同发育阶段器官重的影响为进一步研究母猪妊娠哺乳期日粮蛋白水平对仔猪不同发育阶段器官及肌肉组织重影响,本实验对初生仔猪每窝选择接近平均体重的一公一母在喂初乳前屠宰测定,称其肝脏重、肾重、肾上腺重、心脏重、脾重、脑重、海马重、睾丸重(卵巢重)背最长肌重、腰大肌重并记录。剩余的仔猪由亲生母猪喂养。35日龄断奶时每窝选择一头接近平均断奶窝重的公猪进行屠宰,称其肝脏重、肾重、肾上腺重、心脏重、脾重、脑重、海马重和背最长肌重、腰大肌重并记录。35日龄断奶后所有仔猪转入育肥舍,按原来分组进行并栏(即低蛋白组与低蛋白组并栏,标准蛋白组与标准蛋白组并栏)。育肥期两组后代猪日粮配方及营养成分相同。育肥仔猪饲养至184 d时,选择接近平均体重的育肥猪进行屠宰(对照组8头,试验组8头),记录个体重、头重、肝脏重、肾重、心脏重、脾重、背最长肌重、腰大肌重、板油重。结果显示,初生时总体试验组的心脏重、肺脏重、脑重、海马重没有显著影响(P>0.05),但会导致肝脏、肾上腺(P<0.01)和肾脏重降低(P<0.05)。试验组的内脏率与对照组差异不显著。分性别统计,其中雄性试验组脑、肺、肾脏、海马、肾上腺和性器官重均与对照组差异不显著(P>0.05)。但对肝脏、心脏重和肾脏率有影响(P<0.05)。雌性仅对肝脏重有影响(P<0.01),其它器官差异均不显著(P>0.05)。以上说明,低蛋白对器官重的影响有一定的性别差异；试验组的背最长肌重量、腰大肌重量以及背最长肌率、腰大肌率与对照组差异都不显著(P>0.05),说明低蛋白对初生猪的背最长肌和腰大肌没有显著影响(P>0.05)。断奶仔猪,试验组的脑重、肺重、海马重、性器官重均与对照组差异不显著(P>0.05)。但肝脏重、肾脏重、脾脏重和肾上腺重降低(P<0.01),心脏重也低于对照组(P<0.05)。低蛋白对主要脏器指数没有影响(P>0.05)仅脾脏率、脑重率降低(P<0.05)。试验组的背最长肌重低于对照组(P<0.01),腰大肌重也低于对照组(P<0.05),试验组的背最长肌率低于对照组(P<0.01),而腰大肌率没有显著影响(P>0.05)。这些说明,低蛋白仅对断奶仔猪部分器官重有影响；育肥猪,试验组的肝脏重、肾脏重、脾脏重、心脏重及其脏器指数均与对照组无显著差异(P>0.05),试验组与对照组背最长肌重、腰大肌重及其脏器指数也均无显著性差异(P>0.05),但板油重低于对照组(P<0.05)。以上结果提示：梅山母猪妊娠、哺乳期日粮低蛋白水平对仔猪多数器官的发育无不良影响,尽管有些指标有变化,但对母猪生产性能有好处,也并不影响育肥仔猪的生长性能。3梅山母猪妊娠、哺乳期日粮蛋白水平对胎盘和仔猪不同阶段血清抗氧化酶活性的影响为了进一步研究母猪妊娠、哺乳期日粮蛋白水平对胎盘和仔猪不同阶段血清抗氧化酶活性的影响,对照组和试验组妊娠期70胎龄时各屠宰4头母猪,采集胎盘组织样立即放入液氮然后转入-70℃冰箱保存,用于胎盘抗氧化酶活力的测定；血清采集分别采集屠宰初生仔猪、断奶仔猪和育肥猪血浆,然后4℃2500 rpm离心10 min,取上清,分装于effendorf管,-20℃保存待测。分别用黄嘌呤氧化酶法测定SOD活性,硫代巴比妥酸法(TBA)测定MDA活性,铁离子法测定T-AOC活性,二硫代二硝基苯甲酸法测定GSH-Px活性,钼酸铵法测定CAT活性。结果显示：70胚龄仔猪胎盘蛋白含量和SOD、MDA、CAT含量两组差异不显著(P>0.05),仅有胎盘T-AOC低于对照组(P<0.01), GSH-Px低于对照组(P<0.05)。总体统计初生仔猪血清的MDA. CAT、T-AOC差异不显著(P>0.05),SOD低于对照组(P<0.05), GSH-Px低于对照组(P<0.01)；按公母分开统计,多数指标差异均不显著(P>0.05),仅有雄性GSH-Px试验组低于对照组(P<0.01),雌性GSH-Px试验组低于对照组(P<0.05)。断奶仔猪试验组MDA、GSH-Px、CAT、T-AOC差异均不显著(P>0.05),SOD显著低于对照组(P<0.05)。184日龄育肥猪的血清SOD、MDA、CAT、T-AOC、GSH-Px试验组和对照组差异均不显著(P>0.05)。以上结果提示：尽管梅山母猪妊娠、哺乳期日粮低蛋白水平对仔猪胎盘造成了氧化损伤,胎儿可能处于氧化应激状态,从而使胎猪重、仔猪出生重和断奶重降低,但仔猪恢复营养后,氧化应激解除,出现了显著的补偿生长。这说明梅山母猪日粮适当采用低蛋白,对后代育肥猪发育无影响,且能提高养殖经济效益。更多还原

【Abstract】 Presently, The current nutritional standards of the local breeds in China, almost all reference to foreign standards system, however, the formation history of our local pig breeds, size structure, feeding habits are very different of from foreign breeds. In addition, too much protein supply on feed to production sow, often result in increased fecal N discharge to the environment caused by pollution. Therefore, reasonable requirement of nutrients to domestic breeds come into a interesting research feild. Meishan pigs, originated in the Taihu Lake Basin, characterized with crude resistance high reproductive because of the natural environment and long-term low protein diet to it. With the promotion of intensive feeding, the diet Composition of Meishan pigs from the original green and crude food change to mainly concentrated feed, and the litter size also appears to decline. To test the effects of dietary protein on Meishan sows and their offspring, we fed Meishan sows diet with different protein levels during pregnancy and lactation (dietary crude protein content in control group sows during pregnancy is 12%, during lactation is 14%. dietary crude protein content in low-protein group sows is 50%of control). The body weight, organ weight and muscle weight of piglets, at different stages were detected. To further study the effects of diet protein levels to sow during gestation and lactation on antioxidant capacity in serum of piglets, we examined antioxidant enzyme activity of 70 embryonic pig placenta and the serum of piglets after the birth at different stages. These studies will further prove that Meishan sows reasonable level of protein nutrition to service Meishan pig feeding and management.1. Effect of maternal dietary protein level during gestation and lactation on parturition, piglet development and the economic benefitTwenty-four pure-breed primiparous Meishan sows were randomly divided into standard protein (SP) and low protein (LP) diet groups. Sows of SP group were fed diet containing 12%and 14%crude protein, while LP sows were fed contains 6%and 12% crude protein during pregnancy and lactation, respectively. Eight (4 from the SP,4 from the LP) sows were killed on day 70 of gestation. Placenta and feotuses were weighted; The other sows were raised following the standard feeding regimen with the starter until the parturition. newborn piglets were weighted and analyzed body size at parturition. Litter size was adjusted to 7 to 8 pigs per litter at 24 h post farrowing in the same group. Newborn piglets were allowed free access to their mothers and weaned at 35 days (d) of age. All piglets are weighted at weaning. After weaning, piglets were raised following the standard feeding regimen with the starter, grower and finisher diets recommended for the breed. The finishing at 184 days (d) of age were weighed and slaughed.The results showed that 1) feotuses weight of LP group decreased significantly (P< 0.05); the female feotuses of LP exhibited significantly lower body weight (P<0.05), but the male foetuses of LP group did not differ from that of SP group on body weight (P< 0.05).2) No difference was determined for placental weight between SP and LP groups.3) No difference were detected for the gestation, but the parturition time of LP group decreased by 22.63%(P> 0.05), interval of littering shortened by 28.96%(P>0.05).4) The mean number of the pigletsr from SP and LP was 8.55 and 10.25, respectively, and average survival piglets were 7.91 and 9.00, which exhibited that LP increase piglets number, but no significant difference in statistical analysis values. Survival rate of LP group decreased by 2.64%compard with SP group. Litter weight at birth of LP decreased by 14.4%with but no significant difference.5) No significant difference were analyzed for body height, body length, chest circumference between SP and LP.6) Piglets weight of LP group decreased by 1983.89g at weaning compared with SP group (P<0.01). But no significant difference in fattening weight were detected between SP and LP.These results indicate that maternal low-protein diet during pregnancy and lactation restricts fetal growth and development, and reduces fetal body weight on 70 d Embryo, piglet weight at newborn and weaning, and organ and muscle weight; LP didn’t affect the body weight of pigs at finishing stage, and indicates compensatory growth in LP group.2. Effect of maternal dietary protein level during pregnancy and lactation on organs and muscle weight of offspring To further analyze the effect of maternal dietary protein level on organs and muscle weight of offspring during pregnancy and lacatation, piglets at newborn (one male and female from 7-8 SP and LP, respectively) were killed, and liver, kidney, heart, spleen, longissimus muscle and psoas muscle were weighted. The remaining piglet were kept on respective (SP or LP) diets till weaning were killed, and liver, kidney, heart, spleen, longissimus muscle and psoas muscle were weighted. After weaning, piglets were raised following the standard feeding regimen with the starter, grower and finisher diets recommended for the breed. Finishing (184 day of age) stages, the 17 pigs (8/9 from the SP/LP) were killed the body, liver, kidney, heart spleen, longissimus muscle, psoas muscle and leaf fat were weighted for analysis. The result showed that 1) newborn piglet liver weight of LP group decreased by 5.95g compared with SP (P<0.01), kidney weight reduced by 1.128g (P< 0.05),and the adrenal glands weight was significantly lower than SP (P<0.01).But no significant difference was detected in the heart, lung and brain weight. No obvious difference was determined in Longissimus muscle weight, psoas muscle weight, and longissimus and psoas muscle ratio between SP and LP.2) Piglet at weaning, the weight of liver, kidney and spleen of LP decreased by 39.83g,13.03g, and 8.38g compared with SP respectively (P<0.01), but no difference was detected in lung weight. However, the heart weight of LP group showed a tendency of down-regulation. The ratio of brain and spleen to body weight was affected by the different dietary protein level (P<0.05), the other organ parameter was no difference between SP and LP groups. The Longissimus muscle weight of LP group decreased by 19.00g compared with SP(P<0.05), and the psoas muscle weight in decreased by 2.19g(P<0.05). And the ratio of Longissimus muscle in LP group was significantly lower than SP group(P<0.01), however, no difference in rate of the psoas muscle.3)For the fattening pig, no obvious difference was determined in liver, kidney, spleen, heart weight and organ parameter between SP and LP groups, but the offspring organ index of LP group showed a tendency of down-regulation. No significant difference was detected in Dorsi muscle, psoas muscle weight, organ index, and the suet index between SP and LP groups. But the suet weight of LP was significantly lower than SP group (P<0.05).The results indicat that the maternal low-protein diet during pregnancy and lactation has no significant effect on some organ development, in fattening phase, it mainly affects the accumulation of adipose tissue. The decrease of organ weight caused by the maternal low protein diet in pregnancy and lactation, may be involved in the oxidation stress of organism.3. Effect of mternal dietary protein level during sow pregnancy and lactation on antioxidant enzyme activity in placenta and piglet serum.Four sows(from SP and LP, respectively) were slaughtered on day 70 of gestation, placenta samples were taken for analysis. Plasma samples were taken from newborn piglets, weaning piglets and finishing pigs for analysis. SOD, MDA, T-AOC, GSH-Px and CAT activity were determined.The results showed 1) placental T-AOC and GSH-Px activity of LP group was significantly lower than SP (P< 0.01, P< 0.05). On difference was determined in placental SOD, MDA, CAT activity and total protein content between SP and LP group.2) SOD and GSH-Px activity in newborn piglet serum of LP group were significantly lower than SP (P < 0.05, P<0.01), no significant difference was detected in MDA, CAT, AOC activity. But male piglet GSH-Px activity of LP group was significantly lower than SP (P<0.01);female piglet GSH-Px activity of LP group was significantly lower than SP (P< 0.05), and no significant difference was detected in MDA, CAT, AOC and SOD activity between SP and LP groups.3) SOD activity Of weaning piglets in LP group was significantly lower than SP (P<0.05), and GSH-Px, CAT, AOC activity showed a trendency of down-regulation. No significant difference was determined in MDA activity between SP and LP group.4) No difference was detected in SOD, MDA, CAT, AOC, GSH-Px activity of fattening pigs serum between SP and LP group.These results indicate that maternal low-protein diet during gestation and lactation decreased placenta and piglet serum oxidative activity,exposed feotus or piglet to oxidative stress, and associated with low fetal body and birth weight. While after supply of the protein, oxidative stress restore and show significant compensation growth.更多还原