优质猪杂交繁育体系的构建与优化

选用杜洛克、长白、大白3个国外引进品种,冀合白猪专门化母系B1个国内培育品系,以及1个地方品种太湖猪,模拟杂交繁育体系的生物经济学过程,构建了优质猪的杂交繁育体系,并以每头后备母猪平均每年的利润、每头标准化商品猪的利润、每1000头标准商品猪相对应的母猪头数和商品代出栏猪肌内脂肪含量(肉质指标)4个评价指标对杂交繁育体系进行了优化选择,结果在4种杂交配套组合中,杜洛克×(大白×冀合白猪专门化母系B)经济效率和商品代猪肉质最优。     

多重线性回归法测定猪内源磷排泄量及饲料磷真消化率的研究

本研究旨在采用多重线性回归法测定生长猪内源磷排泄量及高粱和豆粕中磷的真消化率。试验选用6头健康大白×长白阉公猪为消化试验动物,平均体重为(23.6±1.23)kg。采用6×6拉丁方设计,设6个磷水平(0.08%、0.15%、0.23%、0.30%、0.38%、0.53%),以豆粕、葡萄糖、玉米淀粉等为基础,以高粱和豆粕为磷唯一来源,配制半纯合试验饲粮。饲粮中添加0.35%Cr2O3作为外源指示剂。试验分6个试验期,每期8d,其中6d适应期,2d收粪期。饲粮中磷表观消化率受饲粮中磷水平的影响(P<0.05),并随饲粮中磷水平的提高由14.88%增大至34.88%。在以g/kgDMI为计量单位条件下,生长猪粪磷的排出量与饲粮磷的摄入量呈线性关系(P=0.0001)。结果表明,多重线性回归法可用于生长猪内源磷排泄量和植物性饲料磷真消化率的测定;以豆粕-高粱型模型饲粮测定出生长猪内源磷排泄量为0.2940g/kgDMI,高粱中磷的真消化率为56.05%,豆粕中磷的真消化率为39.41%。     

氧化应激对断奶仔猪肌体氧化还原状态的影响

本试验旨在研究氧化应激对断奶仔猪机体氧化还原状态的影响。选用24头28日龄断奶仔猪,随机分为3个处理组,每组8个重复,每个重复1头猪,采用单因子试验设计。基础日粮为玉米-豆粕型,以饲喂基础日粮为对照组,饲喂氧化鱼油和腹腔介入12mg/kg体重敌草快(Diquat)为应激组,试验期26d。结果表明:(1)与对照组相比,氧化鱼油和Diquat都造成了脾脏损伤,使脾脏和胸腺指数降低(P<0.05);(2)饲喂氧化鱼油显著增加了脾脏MDA(丙二醛)含量(P<0.05),降低血浆抑制羟基自由基的能力(P<0.05),极显著降低脾脏GST(谷光苷肽-S转移酶)的活力(P<0.01),降低血浆中SOD(超氧化物岐化酶)、GSH-PX(谷胱苷肽过氧化物酶)的活性(P<0.01)和抑制羟基自由基的能力(P<0.05);(3)Diquat极显著增加脾脏MDA的含量(P<0.01),降低脾脏GST的含量(P<0.01),降低血浆中SOD、GSH-PX的活性和抑制羟基自由基的能力(P<0.01),提高MDA的含量(P<0.01)。氧化鱼油和Diquat可诱导断奶仔猪产生氧化应激,并导致了脾脏和胸腺的氧化损伤。     

Experimental study on how brain-dead state affects the heart structure and function of Ba-Ma mini pigs and the mechanism

AIM:To investigate how brain-dead state affects the heart structure and function and the effect of PKC-α in BA-Ma mini pigs.METHODS:Ten Ba-Ma mini pigs were randomized into 2 groups: brain-dead group (n=5),and control group (n=5). The brain-dead model was made by increasing intracranial pressure,while the control group was maintained anesthesia for 24 h. The concentrations of cTnT,TNF-α,IL-1β and IL-6 in serum were determined at 6,12 and 24 h after brain death. At 24 h,heart tissues were observed by HE staining and electron microscope. The expression of PKC-α was detected by immunohistochemistry and RT-PCR.RESULTS:(1) Histological changes of myocardium: flaky bleeding under endocardium and dissolution of myocardium were found in optical microscope. In electron microscope dropsical mitochondria and confluent muscle fiber were found. (2) Changes of serum cTnT: serum cTnT for brain-dead group began to increase gradually since 6 h,and were significantly higher at each time point than those in control group (P<0.05). (3) Changes of inflammatory factors: IL-1β,IL-6,and TNF-α in brain-dead group began to increase gradually since 6 h,and were significantly higher at each time point than those in control group (P<0.05). (4) Changes of PKC-α expression: PKC-α mRNA and protein expressions in brain-dead group increased significantly at 24 h (P<0.05).CONCLUSION:Brain death may evoke heart structure and functional injury,and increase the levels of inflammatory factors and PKC-α. The activation of PKC-α may participate in the process of heart injury.     

Polymorphism of IGFBP2 Gene and Its Association with Meat Quality Traits in Pigs

This study was aimed to analyze the genetic variation of insulin-like growth factor binding protein 2 (IGFBP2) gene effect on meat quality traits in pigs. A pair of primer was designed,which based on DNA sequence of IGFBP2 gene (GenBank accession No.:BV727778). The genetic polymorphism of IGFBP2 gene was detected by PCR-RFLP in Sujiang pig, Jiangquhai pig and Landrace pig, and the association between IGFBP2 gene polymorphism and meat quality traits in three pig breeds was analyzed. The results showed that three genotypes (AA, AB and BB) were detected. The Chi-square test results showed that the genotype distribution of three pig breeds was in Hardy-Weinberg equilibrium (P > 0.05). The polymorphism information content (PIC) were moderately polymorphic in three pig breeds. According to the association analysis of different genotypes, significant difference was found in color value, intramuscular fat content and marbling, the color value (except for Jianquhai pig) and intramuscular fat content of AA genotype were significantly higher than AB and BB genotypes (P < 0.05), the marbling of AA and AB genotypes was significantly higher than BB genotype (P < 0.05). In conclusion,the polymorphism of IGFBP2 gene intron 3 had significant effects on meat quality traits, and was candidate gene for the potential impact on meat quality traits of pigs.     

酵母硒抗氧化作用及其对肥育猪肉品质影响的研究进展

猪肉消费在我国居民的肉类消费中占主导地位,随着生活水平的提高,消费者对猪肉品质提出更高的要求。研究发现,猪肉品质受遗传、营养、饲养管理和环境等因素影响,常用肉色、pH值、肌内脂肪、滴水损失、嫩度和风味等指标表示。氧化应激是影响猪肉品质的主要因素。硒是谷胱甘肽过氧化物酶的重要组成部分,可以通过催化减少有机氢过氧化物生成量而抵抗氧化应激。许多研究表明,在肥育猪日粮中添加酵母硒能有效改善肥育猪肉的抗氧化能力,改善肥育猪的肉色、pH值及系水力等指标,提高肥育猪的肉品质,延长了猪肉货架期。因此综述了酵母硒的抗氧化机理以及对肥育猪肉品质指标的影响,以期为改善肉质的营养措施提供科学依据。     

保水剂对土壤和棉花根系生长发育的影响

【研究目的】基于棉田可持续发展的思想,通过盆栽和田间试验主要研究保水剂对土壤和棉花根系生长发育的影响。【方法】利用茚三酮法、钼蓝法及土壤双向切片法。【结果】试验表明:土壤中的保水剂含量在0.030%￣0.100%范围内,土壤表面蒸发明显降低,pH值趋于酸化;棉花前期根系生长发育加快,表现为根系活力增强,根系干重较大,且在土壤内分布较为合理,土壤深层根系衰减较慢,更有利于棉株均衡生长发育,防止棉花旱衰。【结论】在30￣45kg/hm2用量内能够明显提高棉花的产量,增产幅度达10%以上,铃数增加5.7万￣9.4万个/hm2,铃重增加0.1￣0.19g。     

添加烟酸铬对生长肥育猪的生长性能、代谢及组织学的影响

将选用的 12 0头杜长大杂交生长肥育猪随机分成 4组 ,3组为实验组 ,1组为对照组 .在实验组的日粮中添加 2 0 0、50 0、10 0 0 μg· kg-1烟酸铬 (以 Cr元素计 )进行为期 2个月的试验 .结果表明 :( 1)试验组日增重比对照组分别提高 11.7%、11.1%和 12 .5% ;料重比分别提高 5.5%、5.6%和 4 .2 % .( 2 )添加 Cr对血清中 K+、Na+、Cl-、总蛋白、白蛋白、脂蛋白及血红蛋白无影响 ( P>0 .0 5) ;血清中 Ca2 +、PO3-4 、尿素氮、尿酸、甘油三酯、胆固醇和血糖含量显著下降 ( P<0 .0 5) ;血清碱性磷酸酶、天门冬氨酸转氨酶、丙氨酸转氨酶含量明显升高 ( P<0 .0 5) ;磷酸肌酸激酶含量显著升高 ( P<0 .0 5) ;而乳酸脱氢酶无明显改变 ( P>0 .0 5) .( 3) Cr含量均未超过国家限量标准 .( 4 )未发现器官的组织结构和细胞形态有何改变 .由此可见 ,在生长肥育猪中添加一定量烟酸铬制剂对猪有积极正面效应     

碳酸氢钾对茄子幼苗生长发育的影响

试验以茄子幼苗为试材,确定KHCO3促进茄子幼苗光合速率的最适浓度,以最适浓度研究KHCO3对茄子幼苗生长发育的影响.结果表明:KHCO3促进光合速率的最佳浓度为500 mg/L.KHCO3能提高叶绿素含量,增加叶面积,可溶性糖含量,根、茎、叶的干重,说明KH-CO3能促进光合作用,使光合产物增加.从影响因子看,HCO3对植物的生长发育起主要作用,但K+也有一定的促进作用.     

种植密度与底磷肥用量对绿豆产量的影响

通过２因子４水平复因子试验与统计分析，研究了绿豆种植密度和底磷肥施用量对绿豆产量的影响。结果表明，绿豆种植密度和底磷肥施用量，是决定绿豆产量的主要因素。明确了绿豆的最佳种植密度和底磷肥施用量。