Objective Effects of a highly reduced crude protein diet supplemented with glutamate (Glu) and arginine (Arg) on the intestinal metabolites and microbiota of weaned piglets were examined for aquaculture feed formulation. MethodOne-hundred-ninety-two healthy (26±2)-day-old crossbred (Duroc × Landrace × Large White) piglets with an average body weight of (6.96±0.29) kg were randomly divided into 4 groups. Each group contained 6 replicates of 8 piglets each. Group I (CK) was fed on the control diet that provided 21.16% crude protein (CP). Group II was on a low-protein diet containing 15.97% CP supplemented with some limiting amino acids. Added to the Group II diet, 1.50% Glu was included for feeding Group III and 1.50% Glu plus 1.00% Arg for Group IV. From 11th to 13th day in the 16 d feeding program, metabolites and microbial community in the piglet intestines were monitored.ResultThe fecal putrescine and spermidine of the treatment piglets were similar but significantly lower than those of CK (P＜0.05). The cadaverine in the Groups II and III piglets showed no significant differences but were significantly lower than that of CK or Group IV (P＜0.05), and that of Group I significantly lower than that of Group IV (P＜0.05). No significant differences were observed on the fecal acetic acid and propionic acid among all groups (P＞0.05), but the butyric acid in the piglets of all treatment groups was significantly higher than those of CK (P＜0.05). The intestinal microbiota richness and diversity of the animals under treatments were significantly higher than those of CK (P＜0.05). At phylum level, the relative abundance of Firmicutes in the fecal microbiota of the piglets were significantly higher under the treatments than CK (P＜0.05), but those of Bacteroidetes and Proteobacteria significantly lower than CK (P＜0.05). Significant differences were also observed among the groups at family and genus levels. The relative abundances of unspecified families and unspecified genera under clostridiales were significantly higher under the treatments than CK (P＜0.05), those of prevotellaceae, enterobacteriaceae, and lachnospiraceae were significantly lower under the treatments than CK (P＜0.05), those of lachnospiraceae, lactobacillaceae, blautia, and lactobacillus of Group IV significantly higher than those of CK (P＜0.05), and those of peptostreptococcaceae and terrisporobacter of Group IV were significantly lower than those of CK (P＜0.05). ConclusionA forage of CP being reduced from 21.16% to 15.97% and supplemented with Glu and Arg lowered the intestinal biogenic amines, increased the butyric acid, and enhanced the diversity and richness of microbiota in the weaned piglets.

该研究旨通过全基因组关联分析定位影响长白母猪断奶至配种间隔的候选基因,以期为我国种猪育种工作提供理论参考.本研究以国家某核心育种场1 063头长白母猪的断奶至配种间隔记录和50K基因数据为研究材料,利用GEMMA软件的混合线性模型进行全基因组关联分析(GWAS),鉴定关联分析显著位点.结果表明,长白母猪第一胎次和第三胎次共存在5个显著SNPs.对5个显著位点进行单倍型分析,获得4个单倍型块.筛选到的BTG1、FUT1、FUT2、SCNN1G和CBLB基因可能是影响断奶至配种间隔性状的重要基因,该研究结果可作为以后种猪育种实践提供参考.

本研究主要对大白猪的繁殖性状和乳头数进行遗传参数估计,评估遗传趋势和表型趋势,并探究乳头数对母猪繁殖性状的影响.将乳头数作为繁殖性状的固定效应,对影响大白猪繁殖性状的固定效应进行方差分析,运用DMU软件的DMUAI和DMU4模块,利用单/多性状动物模型估计大白猪繁殖性状和乳头数的遗传参数,并评估这些性状的遗传趋势和表型趋势.结果发现,乳头数对校正21日龄窝重的影响在P<0.05水平显著,对校正21日龄均重的影响在P<0.001水平显著;大白猪乳头数的遗传力为0.156±0.023,属于中等遗传力性状,各繁殖性状的遗传力范围为0.010～0.092,属于低遗传力性状;各繁殖性状遗传相关的范围为-0.306～0.978,表型相关的范围为-0.055～0.970;各繁殖性状的遗传趋势和表型趋势均为先下降后上升,表明该群体的繁殖性状早期选育成效不佳,但在选育后期有所提升.乳头数和校正21日龄均重的遗传趋势和表型趋势波动比较大,表明这2个性状在该群体中并未被选育,在后期选育时,该群体应注重乳头数的选育,以提高大白母猪的繁殖性能.

为快速同时检测多黏菌素抗性基因mcr-1和编码新德里金属-β-内酰胺酶1(NDM-1)的blaNDM-1基因,基于mcr-1和blaNDM-1的保守序列,设计特异性引物和TaqMan探针,创建双重荧光定量PCR检测方法.结果表明,该方法特异性检测仅能扩增阳性质粒,对照菌株均无特异性曲线;组内重复变异系数和组间重复变异系数均小于1.5％;质粒标准品的检出下限为2.28×23拷贝/μL.用该方法对92株分离细菌和24份猪场环境样品进行检测,mcr-1和blaNDM-1基因均显示阴性;24份猪口腔液样品,其中5份样品检测到mcr-1基因,1份猪口腔液中同时携带mcr-1基因和blaNDM-1基因.

[目的] Toll样受体(Toll like receptors, TLRs)作为天然免疫系统中重要的模式识别受体,在抵御病原微生物感染方面发挥着重要作用.研究猪精子核酸识别TLR的表达和分布情况,为精子TLR信号通路相关功能和抗微生物特性的研究奠定基础.[方法] 采用RT-PCR技术检测公猪精子TLR3、7、8和9 mRNA的表达情况,利用免疫荧光方法检测了TLR3蛋白在猪精子上的分布.[结果] RT-PCR结果显示,TLR3、7、8和9 mRNA在猪精子均有表达;免疫荧光试验结果显示TLR3主要分布在精子头部的后部和中段.[结论] 猪精子上核酸识别TLRs的存在以及TLR3分布的区域化提示猪精子可能对病毒及其衍生物感染做出应答,为进一步研究精子TLR信号通路提供依据.

楼房养猪是18亿亩耕地红线制约养殖用地的宏观背景下,向空间要发展、向楼房要效益的创新之举,为中国生猪养殖产业的持续健康迅速发展做出了可贵的探索、尝试与贡献.对于拥有悠久农耕历史和"猪粮安天下"理念的中国大农业而言,楼房养猪将是一个历史发展潮流与产业升级趋势.在业界的一片喝彩声中,我们更应该保持理性和清醒.要对楼房养殖模式有一个客观、理性、科学和正确的认知.惟有澄清了楼房养猪领域的偏见和误区、甄别了空间养殖的特点与优势,并及时总结源于实践的楼房猪舍建设经验和分享楼房养猪相关数据成果,中国全域包含楼房养猪在内的畜牧产业才能步入可持续的良性循环的快车道.

This experiment was conducted to investigate the effects of different dietary energy structures on age of puberty, serum metabolite and hormone concentrations of replacement gilts. Ninety Landrace×Large White replacement gilts with an initial body weight of (61.97±4.37) kg and similar body condition were allocated to 3 groups with 5 replicates per group and 6 gilts per replicate. Gilts in the 3 groups were fed three different ener?gy structure diets of iso?energetic and iso?nitrogenous. The diet of group 1 contained 49.70% starch, 2.81%ether extract ( EE) and 8.95% neutral detergent fiber ( NDF) , the diet of group 2 contained 43.52% starch, 5.68% EE and 12.53% NDF, and the diet of group 3 contained 37.13% starch, 8.73% EE and 16.02% NDF. The results showed that with the decrease of starch and the increase of EE and NDF in diets, backfat thickness of gilts had trended down, but the difference was not significant among groups ( P＞0.05) ; the age of puberty in group 1 was the least, but the difference was not significant among groups ( P＞0.05) ; the estrus ratio in groups 1 and 2 was 10 percentage points higher than that in group 3, but the difference was not significant a?mong groups ( P＞0.05). The serum triglyceride, total cholesterol and glucose concentrations were not signifi?cantly affected by different dietary energy structures ( P＞0.05). The serum insulin growth factor?Ⅰ, leptin and luteinizing hormone concentrations in group 1 were significantly higher than those in group 3 ( P＜0.05) , and the serum gonadotropin?releasing hormone concentration in group 1 was significantly higher than that in groups 2 and 3 ( P＜0.05). There were no significant differences in serum insulin, estradiol and follicle?stimulating concentrations among groups ( P＞0.05). The results indicate that excessively decreasing the starch level and in?creasing the levels of EE and NDF in diets have effects on the secretion of serum metabolic hormones insulin growth factor?Ⅰ, leptin and serum reproductive hormone luteinizing hormone and gonadotropin?releasing hor?mone, and go against the onset of puberty of gilts.[ Chinese Journal of Animal Nutrition, 2019, 31 ( 6) :2891?2897]

[目的]探讨不同饲粮能量结构对二元母猪生长性能、养分表观消化率和血清指标的影响.[方法]选用90头体貌相近、平均体重为(61.97±4.37) kg的长白×大白杂交后备母猪,随机分成3组,每组5个重复,分别饲喂3种不同能量结构的等能等氮饲粮,3个组饲粮能量组成分别为:组1饲粮含有49.70％淀粉、2.81％粗脂肪(EE)和8.95％中性洗涤纤维(NDF);组2饲粮含有43.52％淀粉、5.68％EE和12.53％NDF;组3饲粮含有37.13％淀粉、8.73％EE和16.02％NDF.[结果]随着饲粮淀粉水平的降低和EE、NDF水平的增加,后备母猪日增重(ADG)呈下降趋势(P＜0.1),料重比(F/G)呈上升趋势(P＜0.1).组1和组2饲粮干物质(DM)、粗蛋白质(CP)、粗纤维(CF)、中性洗涤纤维(NDF)、粗脂肪(EE)和粗灰分(Ash)的表观消化率显著高于组3 (P＜0.05),组1与组2间差异不显著(P＞0.05).随着饲粮淀粉水平的降低和EE、NDF水平的增加,血清甘油三酯(TG)和总胆固醇(TC)浓度呈现增加趋势(P＜0.1),血清葡萄糖(GLU)浓度各组间无显著差异(P＞0.05),血清胰岛素(INS)浓度呈现下降趋势(P＜0.1),血清胰岛素样生长因子-Ⅰ(IGF-Ⅰ)、瘦素(Leptin)浓度组1显著高于组3(P＜0.05),组1与组2间、组2与组3间差异不显著(P＞0.05).[结论]过多降低后备母猪饲粮淀粉水平并提高EE和NDF用量,会降低后备母猪养分表观消化率、降低血清激素分泌,影响后备母猪生长性能.

The experiment was conducted to investigate the effects of different amino acid levels in low crude protein dites on age of puberty,serum metabolites and hormone concentration of replacement gilts based on ideal dietary amino acid pattern.96 Landrace× Large White gilts,with initial body weight of (69.01±3.43) kg and similar body conditions,were allocated to 4 groups with 4 replicates per group.The gilts were fed respectively with 4 low-protein diets with different digestible lysine(DLys) levels of 0.61％ (group 1),0.66％(group 2),0.71％(group 3),0.76％ (group 4) for the early phase(70 to 100 kg) and 0.55％ (group 1),0.60％ (group 2),0.65％ (group 3),0.70％(group 4) for the late phase(100 to 125 kg),and based on the same digestible amino acid pattern by adding synthetic amino acids.The results showed that:Serum circulating lysine concentrations was higher with increasing DLys (P＜0.05),but serum triglyeride,glucose concentrations were similar among groups(P＞0.05).The concentrations of serum insulin(INS),insulin growth factor-Ⅰ (IGF-Ⅰ),luteinizing hormone(LH) and estradiol(E2) increased,then decreased with increasing DLys levels,and reached a maximum value in group 3(P＞0.05),the concentration of serum INS in group 3 was significantly higher than those in group 1(P＜0.05).Back fat thickness and ratio of estrus of gilts increased,then decreased with increasing DLys levels(P＞0.05),the age of puberty of gilts in group 3 was significantly lower than those in group 4(P＜0.05).The results indicated,based on ideal dietary amino acid pattern,the daily DLys intake were 17.82 and 17.29 g · d-1 for 70-100 kg and 100-125 kg (DLys level in the low-protein diets should be 0.71％ and 0.65％),respectively,which could increase the concentration of serum metabolites hormones INS,IGF-Ⅰ,and elevate LH,E2 secretion.Meanwhile,reduced the age of puberty and improved the ratio of estrus in gilts.

With the intensive introduction of policies and acts for environmental protection, the farming land shortage situations for domesticated animals are increasingly serious. Innovational multistory pig buildings are introduced to save land resources and thus increase breeding intensities. The following awareness and concerns towards air qualities of animal occupant zones on each floor are being raised among pig producers. In this paper, a wireless sensor network for collecting environmental factors was used to monitor the thermal environments and harmful gases of three representative floors in multistory pig buildings, which were the top floor (7thfloor), the middle floor (5thfloor) and the ground floor (1stfloor). According to the heads of animals and their weights on these representative floors, the ventilation situations were determined to be the less-ventilated, the well-ventilated and the over-ventilated levels by comparing the actual ventilation rates with the floor's desired ventilation rates. Therefore, the differences of indoor environments between various floors and between multi-locations on the same floor were analyzed with respect to each floor's ventilation levels, which eventually revealed the practices of indoor environment in multistory pig buildings. The monitoring was conducted from the 11thto 21stMay 2017 in Fujian province, located in southern China. Seven wireless sensor nodes were deployed on the top, ground and middle floors respectively. Each floor was monitored over 24 hours, from 9 am of the first day to the same 9 am of the next day. The results were summarized as follows: 1) Ventilation levels had a crucial impact on thermal environments. The less-ventilated levels of the 5th floor made the temperature-humidity indexes (THIs) higher than those of other floors, with an average value of 27.9 ± 0.8 close to the upper limit of comfort zone, 28.06. The radiation effects on the top floor increased the maximum temperature value of this floor to 34.5 ℃, 2.8 ℃ higher than that of the ground floor, with a highest day-night temperature difference up to 11.6 ℃. The temperature of the ground floor was kept in a comfortable range with a smaller day-night temperature difference due to the better thermal insulation of its floor, whereas the relative humidity was increased to a maximum of 85.7% by the moisture from the underlying surface, which was integrated to an average THI of 24.9. 2) The overall concentrations of CO2 and NH3on each floor, under the summer ventilation conditions, were far less from the upper concentration limits. The maximum value, average value, maximum difference, and the same time maximum difference of the CO2 concentrations on the 5thfloor were higher than those of other floors, contrasting with the lowest approximated CO2 emission of 1685.6 kg/d among those of three floors, which was due to its less-ventilated levels in 24 hours. The constitution of the buildings' urinary collecting duct system influenced the NH3concentrations dominantly, the lowest concentrations of NH3on the ground floor benefited from the isolation of its urinary ducts from other floor's system. 3) The difference analyses between average environmental factors of various floors and between the environmental factors of different locations on the same floor were conducted. Highly significant differences (P<0.05) were found in most environmental factors of different floors except there was no significant difference of CO2concentrations between the 1stfloor and the 7thfloor. The significant differences (P<0.05) were found in some environmental factors between different locations on each floor, while no significant differences (P > 0.05) existed among other factors. Mechanically ventilated multistory pig buildings are innovative in China at present. To gain a deep understanding of animal occupant zone environments in multistory pig buildings, and further help to find design flaws of mechanical ventilation systems and disadvantages of operation strategies, the monitoring and analysis of thermal environments and harmful gases have been carried out in the multistory pig buildings during pig production, which would build up the theoretical basis and principles to improve environmental control levels of multistory pig buildings.

The present study aimed to explore the promoter activity of Nhlh2 gene and the relationship between the promoter activity and transcription factors in cells,and further provide a theoretical basis for the regulating mechanism of Nhlh2 gene in pigs.Based on the template of porcine ovarian genomic DNA,PCR was used to amplify different length deletion fragments of Nhlh2 gene promoter.These fragments were cloned into pGL3-basic to build the promoter recombinant plasmid,and then were transfected into the porcine ovarian granulosa cells.The relative luciferase activities of these plasmids were further measured by using the dual luciferase assay system.Chromatin immunoprecipitation assay (ChIP) was used to confirm the interaction between YY1,C/EBPβ and the promoter of Nhlh2.Finally,the overexpression and mutant vectors,small interfering RNA (siRNA) of YY1 and C/EBPβ were constructed,the luciferase activity was detected by dual luciferase reporter assay system.Results showed that transcription activity of P7 (-238-+129) region was the highest,-654--238 was the potential region containing the negative regulatory element,and-238--20 was the potential region containing the positive regulatory element;After the bioinformatic analysis and ChIP test,we found the binding sites of YY1 and C/EBPβ at Nhlh2 gene promoter were-101--85 and-153--140,respectively.After mutating the binding sites of YYl and C/EBPβ,the transcription activity of P7 was significantly up-regulated;The overexpression of YY1 and C/EBPβ significantly reduced the transcription activity of P7,and the transcription activity was significantly up-regulated by YY1-siRNA and C/EBPβ-siRNA.These results indicate that the core promoter region of Nhlh2 is-238-+129.Furthermore,YY1 and C/EBPβ respectively bound at-101--85 and-153--140 of Nhlh2 gene promoter to inhibit the transcription of Nhlh2 gene in pigs.

本试验研究二甲酸钾替代抗生素对动物生产性能和肠道健康的影响.试验选择22日龄健康、体况相近断乳仔猪76头(杜×长×大),随机分为2组,每组4个重复,试验组每个重复10头仔猪、对照组每个重复9头仔猪.对照组为基础日粮(含抗敌素40 mg/kg),试验组为基础日粮添加0.8％二甲酸钾(不添加抗敌素).结果表明:试验组和对照组在仔猪日均增重、日均采食量、料重比、腹泻频率和断乳后前3 d总采食量各指标差异不显著(P>0.05),但试验组比对照组日均增重提高12.83％(P>0.05)、日均采食量比对照组提高11.35％(P>0.05)、断乳后前3 d总采食量提高43.21％(P>0.05).试验日粮添加0.8％二甲酸钾具有酸化剂和抗生素的双重作用,可以提高动物生产性能和肠道健康.

This study was to determine the sequence of the core promoter of tachykinin 3 gene (TAC3),and to explore the role of transcription factors in regulation of the TAC3 core promoter region.The deletion fragments of 5'end of TAC3 were amplified by PCR,taking the porcine ear genomic DNA as a model.The fragments were cloned into the pGL3-basic vector to build gene promoter recombinant plasmids,and then were transfected into porcine ovarian granulosa cells.The core promoter region was determined by double luciferase activity analysis.Chromatin immunoprecipitation assay (CHIP) was performed to determine if the transcription factors physically bound to the promoters of TAC3.The transcription factor overexpression vector and the small interfering RNA (siRNA) transfected porcine ovarian granulosa cells were formed,and qRT-PCR was used to detect changes in expression of TAC3 mRNA.The results showed that the deletion fragments of the 5'end of TAC3 were successfully constructed.The double-luciferase reporter system showed that the core promoter region of TAC3 was at-1 310/ -544.The-2 486/-1 633 region might contain negative regulation elements,and the-1 310/-544 region might contain positive control elements.ChIP assay showed that C/EBPβ and YYl bound to the-653/-639 and-873/-856 regions of TAC3,respectively.Overexpression of C/EBPβ and YY1 enhanced the activity of the TAC3 gene promoter (P＜0.05) and raised the mRNA expression level (P＜0.01).Disturbing the expression of C/EBPβ reduced the expression of mRNA of TAC3 (P＜0.01);and disturbing the expression of YY1 also reduced the gene promoter activity (P＜0.05).The findings here suggested that the C/EBPβ and YY1 genes acted on the core promoter region of TAC3,and contributed to the transcriptional activity of the gene.

本试验旨在研究不同赖氨酸水平的低蛋白质饲粮对二元母猪生长性能和血清指标的影响.选用96头平均体重为69.01 kg的长大二元母猪,随机分成4个组,每个组4个重复,分别饲喂4种不同可消化赖氨酸(DLys)水平的低蛋白质饲粮(等能、等氨基酸平衡模式),70～100 kg阶段饲粮DLys为0.61％、0.66％、0.71％和0.76％,100～125 kg阶段饲粮DLys为0.55％、0.60％、0.65％和0.70％.结果表明,70～100 kg阶段,平均日增重(ADG) 0.61％DLys组、0.66％DLys组和0.71％DLys组间差异不显著(P＞0.05),但0.66％DLys组显著高于0.76％DLys组(P＜0.05);料重比(F/G) 0.61％DLys组、0.66％DLys组和0.71％DLys组间差异不显著(P＞0.05),且均显著低于0.76％DLys组(P＜0.05);血清尿素氮(UN)浓度0.66％DLys组和0.71％DLys组间差异不显著(P＞0.05),0.66％DLys组显著低于0.61％DLys组和0.76％DLys组(P＜0.05).100～125kg阶段,ADG各组间差异不显著(P＞0.05);F/G0.60％DLys组显著低于0.55％ DLys组、0.65％ DLys组和0.70％ DLys组(P＜0.05);血清UN浓度0.65％DLys组显著低于0.55％DLys组和0.70％DLys组(P＜0.05),但与0.60％DLys组间差异不显著(P＞0.05).综合试验结果表明,二元母猪70～100 kg阶段和100～125 kg阶段饲粮DLys适宜日摄入量分别为16.57g/d和15.96 g/d,即饲粮赖氨酸水平分别为0.66％和0.60％,能获得较好的生长性能.

This study was conducted to evaluate the effects of different dietary amino acid levels on the growth performance, serum biochemical parameters and amino acid concentrations of prepubertal gilts in growing phase based on ideal amino acid pattern. A total of one hundred and twenty two?line crossbred ( landrace × large white), with (19.00±1.50) kg of average body weight and similar body conditions, were allocated to four groups with three replicates per group and ten gilts per replicate. The corn?soybean meal diets with four different digestible lysine levels were used respectively and the same digestible amino acid pattern ( digestible lysine:digestible sulphur amino acids:digestible threonine:digestible tryptophane=100:60:65:18 ) by adding synthetic amino acids for the early ( 20 to 40 kg) and late ( 40 to 70 kg) growing phases. In 20 to 40 kg phase, the gilts were fed with four diets with different digestible lysine levels of 0.78% (group 1), 0.83%( group 2) , 0.88% ( group 3) and 0.93% ( group 4) . In 40 to 70 kg phase, the gilts were fed with another four diets with different digestible lysine levels of 0.68% (group 1), 0.73% (group 2), 0.78% (group 3) and 0.83% ( group 4) . The results showed as follows: at phase of 20 to 40 kg, average daily gain ( ADG) (569.69 g) of prepubertal gilts was the highest and feed/gain (F/G) (2.24) was the lowest in group 2 (P<0.05) . The concentration of serum urea nitrogen ( UN) in group 2 was significantly lower than that in groups 3 and 4 ( P<0.05) , and there was no significant difference with that in group 1 ( P>0.05) . The concentration of insulin?like growth factor Ⅰ ( IGF?Ⅰ) in group 2 was significantly higher than that in groups 3 and 4 ( P<0.05) , and there was no significant difference than that in group 1 ( P>0.05) . The concentrations of serum ly?sine, threonine in group 2 were significantly lower than those in groups 3 and 4 ( P<0.05) , the concentrations of serum leucine, isoleucine, phenylalanine and valine in group 2 were significantly lower than those in groups 3 and 4 (P<0.05). At phase of 40 to 70 kg, the ADG (787.43 g) was the highest and F/G (2.55) was the lowest in group 3 ( P<0.05) . The concentration of serum UN in group 3 was significantly lower than that in the other groups ( P<0.05) , and the concentration of IGF?Ⅰ was no significant difference among the groups ( P>0.05). The concentrations of serum lysine, threonine in group 3 were significantly lower than those in groups 1 and 2 ( P<0.05) . In conclusion, the optimum level of DLys in gilts weighting 20 to 40 kg and 40 to 70 kg based on this experiment were 0.85% and 0.78%, or 0.61 and 0.57 g/MJ as expressed with digestive energy (DE), respectively.

In order to study the influence of different parities,mating months and birth months on re-productive performance of sows,the performances of 14 466 nets LY (‘Landrance’× ‘Yorkshire’or‘Yorkshire’× ‘Landrance’)sows in a farm of Fujian Province from August 2010 to December 2013 were analyzed.The results showed that the total number of born,number of born alive and parturition rate of 6th parity were all significantly higher than those of 1st parity(P<0.05).The performances of sows which mated in May and delivered in September were the worst.The estrus returning rate of July and August were the highest.The estrus rate of June,July and August were the lowest.The performances of sows which mated in November and Deccember and delivered in March and April of next year were the best.

Food Safety relates to National Economy and the People's Livelihood and the social harmony, which is the radical requirement for social development. Agricultural products are source of food chain. Only tackling from the source, we can guarantee the food safety. At the beginning of this context , it analyzes the various factors that inlfuenced the quality safety for different types of agricultural products, applying the principle of HACCP into the hazard analysis in all aspects of the agricultural products manufacture and process, listing the key control points, conifrming the key limited point and implementing the monitor. When encountering the problems, treasure of correction and contingency plan should be taken, and giving the veriifcation and keeping records. Meanwhile, combining the particularity of agricultural products manufacture to demonstrate the management methods that ensure safety production of agricultural products. According to the actual situation of technology supplies of agricultural products, it should establish the standard system for agricultural products manufacture, so as to realize agricultural products safety, and then realize the food safety.

The study was conducted to evaluate the effects of four dietary digestible lysine levels on the growth performance and serum indices of replacement gilts from 40 to 70 kilograms based on corn-soybean meal with iso-energy and the same ideal amino acid pattern.A total of one hundred and twenty two-line crossbred gilts (Landrace ×Large White),with 40 kg of average body weigh and similar body conditions were allocated to four groups with three replicates per group and ten per replicate.The gilts were fed with four diets with different digestible lysine (DLys)levels of 0.68% (trial group 1 ),0.73% (trial group 2),0.78% (trial group 3)and 0.83% (trial group 4).The results showed that average daily gain (ADG)(787.43 g)were highest and F/G (2.55 )were lowest in trial group 3 (P <0.05 ),the concentration of BUN was significantly lower than that in other trial groups (P <0.05),and the concentration of IGF-Ⅰ was no significant difference among the trial groups (P > 0.05 ).In conclusion,the optimum level of DLys in replacement gilt weighting 40 to 70 kg based on this experiment were 0.78%,or 0.57 g·MJ-1 as expressed with digestive energy (DE).

In this study, the large white pig core group which consisted of eight independent bloodlines with ten boars and fifty sows was established. On-farm testing, individual breeding value estimated by GBS breeding software and the comprehensive selection in-dex were used to select generation core group. After four years breeding, the year average corrected weight of boars increased 7.90%, sows increased 7.41%, which reached the significant difference (P<0.05). The age up to 100 kg weight was shortened to 1.176 day and the average corrected backfat thickness of boars and sows dropped by 9.54% and 7.54% respectively, which reached the significant difference (P<0.05%).The breeding value of backfat thickness up to100 kg weight decreased 0.159 mm, the total number born in-creased year by year, the breeding value of number increased 0.029. Comprehensive selection index increased 3.84%.The results showed that specialized matriline of large white pig with high performance could be obtained through building excellent core breeding group and using hybridization between different strains.

This experiment was conducted to investigate the effects of different lysine level in low-protein diets on performance, serum indices and milk composition of lactating sows based on ideal dietary amino acid pat-tern. Sixty crossbred ( Large White × Landrace) sows with 3 to 5 parity, similar body condition and parturition dates were selected and randomly divided into 4 groups with 15 sows per group, and the lactation period was 21 days. Four groups of sows were fed four low-protein diets with different lysine levels of 0 . 90%, 0 . 95%, 1. 00% and 1. 05%, respectively, and added synthetic amino acids based on the same digestible amino acid pattern. The results showed as follows: 1) weaning litter weight gain and average daily gain in 0. 90% and 0 . 95% groups were significantly higher than those in 1 . 00% and 1 . 05% groups ( P<0 . 05 );the sow weight loss in 0 . 90% group was significantly higher than that in the other groups ( P<0 . 05 ) , but there were no sig-nificant differences in average daily feed intake, weaning to estrus interval and subsequent litter size among 4 groups ( P>0 . 05 ) . 2 ) There were no significant differences in the contents of urea nitrogen and glucose in serum among 4 groups ( P>0 . 05 ) , the contents of serum estradiol and insulin in 0 . 90% and 0 . 95% groups were significantly higher than those in 1. 00% and 1. 05% groups (P<0. 05); the contents of serum lysine, threonine, valine and essential amino acids in 0. 90% and 0. 95% groups were significantly lower than those in 1 . 00% and 1 . 05% groups ( P<0 . 05 ) . 3 ) The milk total protein content in 0 . 90% and 0 . 95% groups was significantly higher than that in 1 . 05% group ( P <0 . 05 ) , the milk solids content in 0 . 90% and 0 . 95%groups was significantly higher than that in 1. 00% and 1. 05% groups (P<0. 05). In conclusion, based on low-protein diets with ideal amine acid patter, the lactating sows can get the optimal performance when dietary lysine level is 0. 90% to 0. 95%.