Polymorphism of FUT1 Gene and Its Relationship with Litter Size in Northeast Hebao Pigs

[ Objective] To analyze the FUT1 gene polymorphism of Hebao pigs and its relationship with litter size and provide reference for conservation, breeding, development and utilization of Hebao pigs. [Method] The DNA was extracted from Hebao pigs＇ ears, and the polymorphism of FUT1 gene was detected by PCR-RFLP. Then the relationship between genotype and litter size was analyzed. [Result] The FUT1 gene had three kinds of genotypes, GG, AG and AA, as indicated by digestion with Hin6 I. The genotype frequency of AA was 0.115 9, and the allele frequency of A was 0.275 4. The average litter size from the 1 = parity to the 5th parity was higher in the individuals with the genotype AA than in those with the genotype AG or GG. And this difference was significant in average litter size of the 3th parity and the 4th parity （ P 〈 0.05）. [ Conclusion ] The FUT-1 gene is polymorphic in Hebao pigs, and the allele frequency is similar to that of foreign Duroc pigs but greatly different from that of other breeds such as Landrace, Large white, and Landrace x Large white pigs. The genotype AA is a prevalent genotype for litter trait.

Analysis of PRLR and BF Genotypes Associated with Litter Size in Beijing Black Pig Population

This study is aimed at using the DNA mutations in the prolactin receptor （PRLR） and properdin （BF） genes to determine associations between the genotype and litter size in the Beijing Black pig population. A total of 321 Beijing Black pig sows were genotyped using the polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） method, with the Alu I and Sma I for PRLR and BF genes, respectively. Two different alleles of PRLR and BF genes were identified： allele A （0.25） and B （0.75） of the PRLR gene, allele A （0.13） and B （0.86） of the BF gene. The association analysis between the genotypes and the litter size were estimated with the method of the general linear model. The analysis results of PRLR showed that in first parity, sows with genotype AA had a larger litter size than sows with genotype AB and BB, but the difference was statistically not significant. In later parities, statistically significant （P 〈 0.05） differences were seen between sows with genotypes AA and AB, and BB of the PRLR gene. The associated analysis results between genotypes and litter size （total number born, TNB, and number born alive, NBA） showed that there were no significant differences in the first parity sows with different genotypes of the BF gene, but significant differences appeared in NBA between the sows of genotypes AB and BB, in later parity, for which significantly higher values were observed in the offspring of heterozygotes. Considering the consistent genotypic effect on the litter size of both sows in first parity and later parity, it was concluded that the locus of the PRLR gene, digested with Alu I, could be the gene maker for the litter size in Beijing Black pigs.

Study on the Effect of ESR and FSH β Genes on Litter Size in Local Northeast Three Pig Breeds

The method of PCR RFLP was used to analyze the effects of ESR and FSH β genotypes on the litter size,especially the corresponding changes with the difference of genotype distributions in the Min,Sanjiang and Junmu I pigs.The results show that the ESR and FSH β genes are the major genes of litter size;the heterozygous genotype for ESR as well as for FSH β locus has a more litter size than others.However,the combined genotype ABDD means a more litter size than other genotypes,the frequencies of the heterozygous genotypes in Sanjiang and Junmu I are lower than in Min which maybe one of the most important reasons for the little litter sizes of those two breeds.

Expression of genes involved in progesterone receptor paracrine signaling and their effect on litter size in pigs

Background： Embryonic mortality during the period of implantation strongly affects litter size in pigs. Progesterone receptor（PGR） paracrine signaling has been recognized to play a significant role in embryonic implantation. IHH,NR2F2, BMP2, FKBP4 and HAND2 were proved to involve in PGR paracrine signaling. The objective of this study was to evaluate the expression of IHH, NR2F2, BMP2, FKBP4 and HAND2 in endometrium of pregnant sows and to further investigate these genes＇ effect on litter size in pigs. Real-time PCR, western blot and immunostaining were used to study target genes/proteins expression in endometrium in pigs. RFLP-PCR was used to detect single nucleotide polymorphisms（SNPs） of target genes.Results： The results showed that the m RNA and protein expression levels of IHH, NR2F2 and BMP2 were up-regulated during implantation period（P 〈 0.05 or P 〈 0.01）. All target proteins were mainly observed in luminal epithelium and glandular epithelium. Interestingly, the staining of NR2F2 and HAND2 was also strong in stroma. SNPs detection revealed that there was a-204 C 〉 A mutation in promoter region of NR2F2 gene. Three genotypes were found in Large White, Landrace and Duroc sows. A total of 1847 litter records from 625 sows genotyped at NR2F2 gene were used to analyze the total number born（TNB） and number born alive（NBA）. The study of the effect on litter size suggested that sows with genotype CC tend to have higher litter size.Conclusions： These results showed the expression patterns of genes/proteins involved in PGR paracrine signaling over implantation time. And the candidate gene for litter size was identified from genes involved in this signaling. This study could be a resource for further studies to identify the roles of these genes for embryonic implantation in pigs.

Association Analysis between a Polymorphism in the 5' Regulatory Region of the IL-6 Gene and Litter Size in Pigs

The aim of this study was to determine the effects of an IL-6 gene polymorphism, discovered in the 5＇ regulatory region, on porcine litter size. An association analysis was performed between the polymorphism and total number born （TNB） and number born alive （NBA） in 421 sows. The polymorphism was at Hpy188I within the 5＇ regulatory region of IL- 6 gene. Three genotypes of AA, AG, and GG were detected in Landrace, and two genotypes, AA and AG, were detected in Yorkshire and Duroc pigs. The A allele was the superior allele in all three breeds, with allele frequencies ranging from 0. 901 to 0.993. The IL-6 genotype was highly significantly associated with TNB and NBA in the third and following parities （ P 〈 0.01 ）, and with total parities （ P 〈 0.05）. In general, the TNB and NBA showed a tendency of GG 〉 AG 〉 AA, indicating that the common allele was the least favorable for litter size. Thus, there is an enormous opportunity to increase litter size if this effect is confirmed in other studies.

基于转录组测序分析猪子宫内膜妊娠中的关键非编码RNA及其调控通路

【目的】探究调控具有不同产仔数的川乡黑猪和藏猪的猪子宫内膜妊娠过程的相关miRNA、lncRNA及靶基因,进一步揭示影响不同品种猪子宫内膜妊娠相关非编码RNA富集的信号通路。【方法】对平均产仔数为11.35和6.70的川乡黑猪和藏猪第2、5胎次的子宫内膜进行分离,提取RNA,质检合格后进行转录组测序,测序数据经过拼接、比对到miRNA和lncRNA并预测其靶基因,进行GO和KEGG富集分析筛选到调控川乡黑猪和藏猪不同产仔数的候选基因以及信号富集通路。【结果】不同胎次的川乡黑猪和藏猪之间存在多个miRNA、lncRNA及靶基因的差异表达,其中第2胎次具有1571个miRNA和2042个lncRNA差异表达,第5胎次具有1042个miRNA和2096个lncRNA差异表达。进一步根据靶基因的GO和KEGG富集分析发现川乡黑猪在促性腺激素释放激素(GnRH)分泌、ECM受体互作以及Wnt信号通路等的富集程度高于藏猪。同时发现川乡黑猪相比藏猪有醛固酮调节钠重吸收、谷胱甘肽代谢、果糖和甘露糖代谢等过程的富集。此外,已鉴定的关键候选调控基因包括FSHR(Follicle stimulating hormone receptor)、DBX1(Developing brain homeobox 1)、ARID2(AT-rich interaction domain 2)、TNC(Tenascin C)、NT5C2(Neuropilin 2)、LAMC3(Laminin subunit gamma 3)、MADD(MAP kinase activating death domain)等。【结论】高产仔数的川乡黑猪相比低产仔数的藏猪在子宫内膜妊娠过程中有更高的促性腺激素释放激素(GnRH)分泌、ECM受体互作以及Wnt信号通路富集(GO分析结果),同时也有代谢途径的参与(KEGG分析结果)。涉及到的关键调控基因主要有FSHR、DBX1等。本研究为探究非编码RNA在猪子宫内膜妊娠过程中的功能及其分子调控机制提供了新的思路。

微生物发酵床养猪垫料研制番茄育苗基质的效果分析

为了实现废弃资源的资源化利用,使用微生物发酵床养猪垫料研制番茄育苗基质,选取使用1年的微生物发酵床养猪垫料,提取其浸提液并稀释成不同浓度,以番茄种子萌发情况为指标,筛选基质中垫料适宜添加量,并通过穴盘育苗试验确定基础基质配方,进一步优化N、P、K用量,最终确定番茄育苗基质配方。结果表明:利用微生物发酵床养猪垫料研制番茄育苗基质的配方为垫料︰椰糠=3︰7(体积比),N用量0.3 kg·m^(−3)、P用量0.2 kg·m^(−3)、K用量0.1 kg·m^(−3);用该基质进行番茄育苗,出苗率达98%,幼苗的株高、茎粗、根长均显著优于市售草炭基质(对照);所繁育的幼苗移栽田间种植,其田间番茄苗的株高和挂果数均显著优于对照。番茄育苗基质的研制可实现微生物发酵床养猪垫料的资源化利用。

杜陆母猪与川乡黑猪杂交产仔性能及后代毛色分析

为了测定杜洛克×陆川(杜陆)二元母猪产仔性能及其与川乡黑猪杂交后代毛色情况,本研究记录了海南省3个川乡×杜洛克×陆川(川杜陆)三元商品猪生产场在2022年1月至2023年6月期间的共计5862窝有效繁殖情况,根据胎次和猪场对母猪产仔性能进行了比较,并统计了三元商品猪的毛色性状。结果显示:总产仔数、产健仔数及初生窝重在不同猪场间存在差异显著(P<0.05)。胎次比较发现2、3、4、5胎的总产仔数和产健仔数差异不显著(P>0.05),第1胎的各项指标显著低于其他胎次(P<0.05),6胎及以上的指标也与其他胎次差异显著(P<0.05)。第4胎的窝重显著低于其他胎次,而第2胎窝重显著高于其他胎次(P<0.05)。试验组所产仔猪主要为黑毛色,少数为红毛色,极个别为白毛色,平均黑毛色比例达98.79%。综上所述,不同猪场间母猪的产仔性能有显著性差异,2~5胎母猪繁殖力强,仔猪初生窝重有显著差异性;川杜陆三元商品猪绝大多数为黑毛色。

Genetic Effects of ADAMTS-1 Gene on Reproductive Traits in Landrace Pig

The nucleotide sequences in exon 7 of a disintegrin and metalloproteinase with thrombospondin motifs-1(ADAMTS-1)gene in Landrace pig were obtained with cloning and sequencing by using PCR-RFLP technique in this experiment.Sequence alignment results showed that the C/G substitution in exon 7 induced amino acid change(Arg → Pro).AA,BB and AB genotypes were found in Landrace pig by PvuⅡ-RFLP.Correlation analysis between genotypes and reproductive traits indicated that ADAMTS-1 was significantly correlated with litter size(LS)and number born alive(NBA).

Characterization of Porcine Matrix Metalloproteinase 23 (pMMP-23) Gene and Its Association with Litter Size Traits

The matrix metalloproteinase 23 （MMP-23）, which might play a role in ovulation in mammals, was one of the promising candidate genes for litter size traits in pigs. In the present research, partial sequence of porcine MMP-23 （pMMP-23） gene, including exons 2-8 （GenBank： EU360790）, was obtained. Real-time PCR analysis revealed that pMMP-23 gene was highly expressed in ovary. PCR-Sau3A I-RFLP and PCR-Acc II-RFLP assay were established to detect a C/T mutation in exon 3 （EU360790： g. 269C〉T） and an A/G mutation in exon 4 （EU360790： g. 505A〉G）, respectively. Association study for these two SNPs with litter size was assessed in three independent populations （Minzhu, Landrace I and Landrace II）. Statistical analysis demonstrated that for second and subsequent litters, TT sows produced more TNB than CC pigs in Landrace breed （P〈0.05） at g. 269C〉T locus, and the additive effect was significant （P〈0.05）; GG sows produced more TNB and NBA than AA pigs in Minzhu （P〈0.01） and Landrace breeds （P〈0.05） at g. 505A〉G locus, and the additive effect was significant （P〈0.01 or P〈0.05）. Our study suggested that the pMMP-23 gene might be a novel candidate gene for litter size traits, and g. 505A〉G locus might be a useful molecular marker for marker assisted selection （MAS）.

Erythropoietin Receptor Gene (EPOR) Polymorphisms are Associated with Sow Litter Sizes

The erythropoietin receptor （EPOR） has shown to play an important role in fetal survival by promoting the maturation of red blood cells in many studies of uterine capacity and litter size in swine. In this study, we screened the porcine EPOR gene for mutations and identified five single nucleotide polymorphisms （SNPs）： g.705G〉T in intron 1, g.2 373C〉T in intron 4, and g.2 882C〉T, g.3 035A〉G, and g.3 132A〉T in intron 6. We then genotyped 247 Beijing Black （BB） sows and compared the polymorphism data with the litter sizes of 1 375 parities among the sows. At first parity, there was no association of g.2 882C〉T and g.3 132A〉T with litter sizes. However, the CT sows in g.2 882C〉T had 2.13 higher total number born （TNB） （P〈0.01） and 1.81 higher number born alive （NBA） （P〈0.01） than the CC sows and the heterozygous sows in g.3 132A〉T had the highest litter size when compared to the two homozygotes for the later parities （P〈0.05）. In the g.3 035A〉G SNP, for the later parities, the TNB of the sows with the GG genotype was 3.81 higher （P〈0.01） and the NBA was 2.75 higher （P〈0.01） than that with the AA genotype but no difference at first parity. The G allele of the EPOR g.705G〉T SNP was associated with a greater litter size at both the first parity （P〈0.05） and later parities （P〈0.01）. Furthermore, we determined the allele frequencies for this SNP among five Chinese indigenous pig breeds （Erhualian, Laiwu Black, Meishan, Min, and Rongchang） and three western commercial pig breeds （Duroc, Landrace, and Large White）. The G allele of the EPOR g.705G〉T SNP was significantly more common in the more prolific Chinese breeds. These results indicated that the EPOR could be an important candidate gene for litter size and g.705G〉T can serve as a useful genetic marker for improving litter size in both first and later parities in swine.

Identification of Novel Polymorphisms in Porcine Ring Finger Protein 4 and Matrix Metalloproteinase 9 Genes and Association Analysis with Litter Size Traits

Reproduction trait plays an important role in pig production. Identification of molecular markers that are linked to litter size may contribute to the genetic development of porcine reproduction traits. In this study, porcine ring finger protein 4 （pRNF4） and Matrix metalloproteinase 9 （pMMP-9） were selected as candidate genes on the basis of their physiological roles in reproduction. Two single-nucleotide polymorphisms （416C〉T in pRNF4 and - 1257G〉A in pMMP-9） that could be detected by PCR restriction fragment length polymorphism （PCR-RFLP） were discovered and tested for statistical associations with litter size traits in three populations. For 416C〉T, TT genotype was associated with a significantly higher （p〈0.05） number of live births than those recorded for CC sows and the additive effect was significant （p〈0.05） in Qingping and Min Pigs populations in later parities. For -1257G〉A, inconsistent results were found in three populations. The results suggested that T allele in pRNF4 gene might confer a high prolificacy in breeding and further studies were needed to confLrm the results.

猪MMP9基因的多态性与产仔数性状的关联分析

通过比较序列测定法,在MMP9基因第10内含子发现C/T突变,建立了PCR-Sma I-RFLP分型技术,并在淮猪新品系Ⅱ猪种中进行多态性分型,分析其基因型频率和等位基因频率,检测该位点的多态性并与产仔数性状进行关联分析。结果表明,在淮猪新品系Ⅱ猪群中,所有胎次产仔数呈TC>CC>TT的趋势,TC型个体的所有胎次产仔数显著高于CC型个体0.776头(P<0.05)。因此,MMP9基因在淮猪新品系Ⅱ猪群中与产仔数性状显著相关,为提高猪产仔数性状提供一个有用的分子标记。

荣昌猪初产繁殖性状的全基因组关联研究

旨在鉴定荣昌猪初产繁殖性状的重要变异位点和基因,为荣昌猪繁殖性状的遗传改良提供重要的分子标记和基因资源。本研究选取429头荣昌母猪进行猪50K芯片基因分型,经过质量控制和基因型填充后,保留35 046个SNPs用于分析。采用主成分分析法研究群体结构,利用混合线性模型(mixed-linear model, MLM)将出生年、出生月作为固定效应,将主成分值作为协变量对总产仔数、活产仔数、死胎数和初生窝重性状进行全基因组关联分析(GWAS)。结果显示,在全基因组显著水平上鉴定出2个影响荣昌猪初生窝重的SNPs和1个影响荣昌猪死胎数的SNP;在潜在显著水平上鉴定到5个影响荣昌猪总产仔数的SNPs, 3个影响荣昌猪活产仔数的SNPs和10个影响荣昌猪死胎数的SNPs。通过全基因组关联分析筛选到1个显著的SNP(SSC17:57 315 180 bp)同时影响荣昌猪总产仔数、活产仔数和初生窝重,1个显著的SNP(SSC1:279 214 647 bp)同时影响荣昌猪活产仔数和总产仔数,暗示基因在不同性状间具有一因多效性。本研究根据候选基因的相关分子生物学功能,确定BMP7基因为影响荣昌猪总产仔数、活产仔数和初生窝重的重要候选基因,MSH3和CBLB基因为影响荣昌猪死胎数的重要候选基因。以上结果为荣昌猪繁殖性状提供了重要的遗传变异位点和候选基因,也为荣昌猪繁殖性状的基因组选择提供了重要的理论基础。

季节和胎次共同作用对大白猪繁殖性能的影响

为了研究胎次及其与配种季节和分娩季节共同作用对大白猪母猪繁殖性能的影响,试验选取了河南某种猪场7373窝大白猪母猪的产仔数据,包括总产仔数、活仔数、弱仔数、死胎数、出生窝重、断奶数、21日龄校正窝重7个指标,分析了胎次及其与配种季节和分娩季节共同作用对繁殖性能的影响,以及上述8个繁殖性能指标间的相关性。结果表明:2,3胎次的总产仔数、活仔数高于或显著高于其他胎次(P>0.05或P<0.05),3胎次的出生窝重显著高于其他胎次(P<0.05),产仔性能最好的是2,3胎次,其次是4,5胎次,较差的是1胎次和5胎次以上;春季配种时2,5胎次的总产仔数、活仔数、出生窝重高于或显著高于其他胎次(P>0.05或P<0.05),夏季、秋季配种时2,3胎次的总产仔数(秋季2胎次除外)、活仔数和出生窝重(秋季2胎次除外)高于或显著高于其他胎次(P>0.05或P<0.05),2胎次适宜在夏季配种,3胎次适宜在夏季、秋季配种,4胎次适宜在冬季配种,5胎次适宜在春季配种,1胎次和5胎次以上适宜在冬季配种;春季分娩时3胎次的总产仔数、活仔数高于或显著高于其他胎次(P>0.05或P<0.05),夏季、秋季和冬季分娩时2,3,5胎次的活仔数、出生窝重和断奶数总体高于或显著高于其他胎次(P>0.05或P<0.05),2胎次适宜在秋季分娩,3胎次适宜在冬季分娩,4胎次适宜在春季分娩,5胎次适宜在夏季分娩,1胎次和5胎次以上适宜在夏季分娩;除分娩季节与活仔数和出生窝重不显著相关外(P>0.05),胎次及其与配种季节和分娩季节交互作用均与7个指标呈显著或极显著相关(P<0.05或P<0.01);7个繁殖性能指标多数呈显著或极显著正、负相关(P<0.05或P<0.01)。说明产仔性能较好的2胎次适宜在夏季配种秋季分娩,3胎次适宜在夏季、秋季配种冬季分娩,4胎次适宜在冬季配种夏季分娩,5胎次适宜在春季配种夏季分娩;产仔性能较差的1胎次和5胎次以上适宜在冬季配种夏季分娩。

杜洛克猪瘦肉率性状的窝效应分析及遗传参数估计

旨在评估瘦肉率性状的遗传参数及其主要生长性状之间的关系,并分析窝效应对瘦肉率和主要生长性状的影响,为瘦肉率性状的改良提供参考。本试验以广东中芯种业科技有限公司下属某核心场杜洛克猪群体(26392头)的校正115 kg瘦肉率(corrected 115 kg lean meat percentage,LMP)、校正115 kg日增重(corrected 115 kg daily gain,ADG)、校正115 kg背膘厚(corrected 115 kg backfat thickness,BFT)和校正115 kg眼肌面积(corrected 115 kg loin muscle area,LMA)性状为研究对象,利用R软件对影响杜洛克猪LMP、ADG、BFT和LMA性状的固定效应进行方差分析,并利用DMU软件计算了考虑和不考虑窝效应情况下LMP性状的遗传参数,评估其与生长性状间的遗传和表型相关。结果显示,上述各性状的表型记录数量均达到了20000条以上,当考虑窝效应时LMP性状的遗传力为0.34±0.019;不考虑窝效应时LMP性状遗传力为0.45±0.017。LMP与ADG性状的遗传相关系数较小,但与LMA性状呈极显著正相关。此外,该杜洛克群体的LMP、ADG、BFT和LMA性状的窝效应在总体方差中的比重分别为0.15、0.21、0.15和0.14,且LMP年平均估计育种值(estimated breeding value,EBV)呈上升趋势。上述结果说明,该杜洛克群体的LMP、ADG、BFT和LMA的遗传力均属于中等遗传力,且受窝效应影响较大。在遗传评估模型中考虑窝效应作为随机效应进一步提高了模型对上述性状的拟合效果,增加了遗传评估的准确性,此外如母体遗传效应等对上述性状的影响仍需进一步探讨。上述结果说明,眼肌面积受到了瘦肉率性状的协同选择,进一步说明了目前瘦肉率估算方程中将眼肌面积作为辅助性状的原因。

德保猪的繁殖性能研究

为了研究德保猪的繁殖性能,试验采集了75,82,113,115,120日龄德保母猪卵巢,利用石蜡切片方法对德保母猪的初情期进行研究;选择8头后备德保母猪和9头经产德保母猪对其发情周期进行研究;统计20头初产德保母猪和5头经产德保母猪的产仔数据,计算母猪窝平均产仔数、仔猪平均出生重、公母比例(公∶母)、出生存活率和35 d断奶存活率;观察14头德保小公猪的爬跨行为对其初次爬跨行为进行研究;采集15,26,28,30,32,34,36,38,40,42,43,44,45,46,47,49,51,53,55,62,70日龄德保公猪睾丸,利用石蜡切片方法对德保公猪睾丸初次产生精子的日龄进行了研究。结果表明:德保母猪的初情期在120日龄左右,后备和经产德保母猪发情周期分别为(26.00±2.00)d和(23.89±1.97)d,差异显著(P<0.05);初产德保母猪的窝平均产仔数为(7.45±1.80)头,显著小于经产德保母猪[(10.00±2.10)头,P<0.05],但初产德保母猪的仔猪平均出生重、公母比例(公∶母)、出生存活率、35 d断奶存活率与经产德保母猪差异不显著(P>0.05);德保小公猪最早出现爬跨的日龄是8日龄;德保公猪睾丸初次产生精子的日龄是45日龄。说明德保母猪具有发情周期长的特点,德保公猪是较早出现爬跨行为、曲细精管较早出现精子的品种之一,具有明显的性早熟特征。

发酵床养猪废弃垫料的资源化利用评价

发酵床养殖技术是基于控制畜禽粪尿排放与污染的一种新型生态养殖模式,但其有机废弃物的处理和应用值得进一步研究。本文测定了我国山东、吉林两省5个发酵床养猪场的废弃垫料的有机质、氮、磷、钾、重金属元素、抗生素和盐分含量以及有害微生物数量。结果表明,废弃垫料中富含有机质、氮、磷、钾等营养元素。其中有机质含量为42.62%～54.12%,全氮1.54%～2.12%,全磷(P2O5)2.24%～5.55%,全钾(K2O)0.57%～2.15%;Cu、Zn、Cr、As、Ni、Pb、Cd、Hg等8种重金属元素含量均符合国家有机肥料农业行业标准(NY 525-2012)和城镇垃圾农用控制标准(GB 8172-1987)的限量标准;土霉素(Oxytetracycline,OTC)、四环素(Tetracycline,TC)、金霉素(Chlortetracycline,CTC)等四环素类抗生素含量低,环境风险小;蛔虫卵和大肠杆菌含量均超过NY 525-2012和GB 8172-1987的规定限值,蛔虫卵死亡率范围为90%～94%,总大肠杆菌的数量范围为1.29×105～2.24×106cfus/g;垫料盐分含量达到22.11～45.71g/kg。评价结论:发酵床废弃垫料具有有机肥料的基本性质,但是盐分含量偏高;肠道寄生虫卵严重超标,具有生物安全隐患,施用前必须对其进行无害化处理。

发酵床养猪垫料的养分转化与植物毒性研究

发酵床养殖技术也被称为原位堆肥技术,是一种值得推荐的控制畜场粪便排放与污染的生态养殖模式。本研究检测了发酵床的水分、温度和pH值变化以及在连续饲养两批猪后垫料中碳、氮和磷的组成与含量变化情况及其对植物毒性的强弱。结果表明,发酵床使用期间水分为58%-61%,垫料内部温度维持在40-55℃;在连续饲养两批猪后,垫料的pH值升高至8.16,氮、磷含量显著提高,铵态氮、亚硝态氮和硝态氮浓度显著升高,C/N比由养猪前的84∶1下降至31∶1,N/P比由2.8∶1下降至1.26∶1;垫料中的总铜浓度由7mg·kg^-1升高至89mg·kg^-1。以白菜种子作发芽试验考察废弃垫料的植物毒性,其相对发芽率为86.67%,相对根长为132.95%,发芽指数（Germination Index,GI）为115.23%,说明饲养了两批肥猪的发酵床垫料无植物毒性作用,对根的生长有促进作用,可作为有机肥还田。

5个与猪产仔数相关基因的效应分析

为了比较不同基因对猪产仔数效应大小，在相同的大白（158头）、长白（224头）猪群中采用PCR-RFLP法进行了ESR、FSHβ、PRL、PRLR、NCOA15种与产仔数相关基因的基因型频率检测及不同基因型的总产仔数和产活仔数效应分析，结果表明，对相同母猪群产仔数影响效应最大的是PRLR和NCOA1基因，AA型比BB型母猪总产仔数高2．28～3．33头（P〈0．01），产活仔数高1．57～3．30头（P〈0．01），其次为ESR和FSHβ基因，BB型比AA型母猪总产仔数高0．55～1．18头（P〈0．05，长白例外），产活仔数高0．37～1．20头（P〈0．05）。PRL基因对产仔数效应不显著。