梅山猪与杜洛克猪中等卵泡差异表达基因的鉴定

本试验采用抑制性消减杂交技术构建了卵泡期第4天梅山猪和杜洛克猪中等卵泡M2组织差异表达的消减cDNA文库,从中筛选差异表达的基因,并通过实时荧光定量PCR对其进行验证,利用DAVID软件对差异表达的基因进行聚类分析。结果表明,从梅山猪和杜洛克猪M2卵泡消减文库中筛选得到了148和75个差异表达的ESTs,分别含有125和60个已知的基因。实时荧光定量PCR验证结果与筛选结果相符。GO功能分类注释到调控代谢、细胞循环、生物合成、胞内转运、类固醇雌激素受体和刺激等生物学过程。KEGG Pathway分析表明有6个基因参与TGF-beta信号通路,5个基因参与卵母细胞减数分裂信号通路,7个基因参与类固醇雌激素受体信号通路,推测TGF-beta信号通路中的基因可能调控猪卵泡的发育。研究结果为深入探讨卵泡发育机理和对繁殖性状影响的遗传机理奠定了基础。     

Dietary linseed oil in the maternal diet affects immunoglobulins,tissue fatty acid composition and expression of lipid metabolism‐related genes in piglets

This experiment investigated the effects of supplementing the maternal diet with linseed oil (LSO) and soya bean oil (SBO) on immunoglobulins, the fatty acid composition and hepatic expression of lipid metabolism‐related genes in piglets. Multiparous sows (twenty‐four per diet) were fed on diets containing a supplement of either SBO or LSO during last week of gestation and lactation. The results indicated that supplementation of maternal diet with LSO could improve the weaning weight of piglets and average daily gain (ADG) (p < 0.05). The concentration of immunoglobulin G (IgG) and immunoglobulin A (IgA) was enhanced in sow plasma, colostrum and milk by the addition of LSO (p < 0.05). In addition, the concentration of 18: 3n‐3 fatty acids was higher in the milk of LSO sows. Meanwhile, maternal supplementation with LSO increased the levels of plasma IgG, IgA and the tissues n‐3 polyunsaturated fatty acid (PUFA) in piglets (p < 0.05). Correspondingly, the mRNA expression levels of hepatic ?5‐desaturase (D5D) and ?6‐desaturase (D6D) were higher, and fatty acid synthase (FAS) was lower in piglets from LSO‐fed sows when compared with that in the SBO group. In conclusion, LSO supplementation of the maternal diet increases immunoglobulins, modifies the fatty acid composition and affects the gene of D5D and D6D expression of piglets.     

基于全卷积网络的哺乳母猪图像分割

猪舍场景下,光照变化、母猪体表颜色不均及与环境颜色对比度不大、母猪与仔猪的粘连等,均给目标分割带来很大的困难。该文提出了基于全卷积网络(FCN,fully convolutional networks)的哺乳母猪图像分割算法。以VGG16为基础网络,采用融合深层抽象特征与浅层细节特征并将融合的特征图上采样8倍的跳跃式结构,设计哺乳母猪分割的FCN。利用Caffe深度学习框架,以7栏伴有不同日龄仔猪的3811幅哺乳母猪训练样本进行母猪分割FCN训练,在另外21栏的523幅哺乳母猪测试集上的分割结果表明:该算法可有效避免光线变化、母猪颜色不均、小猪遮挡与粘连等影响,实现完整的哺乳母猪区域分割;分割的平均准确率达到99.28%,平均区域重合度达到95.16%,平均速度达到0.22 s/幅。与深度卷积网络的SDS(simultaneous detection and segmentation)及传统的基于图论的图像分割、基于水平集的图像分割方法做了对比试验,该文分割方法平均区域重合度分别比这3种方法高出9.99、31.96和26.44个百分点,有较好的泛化性和鲁棒性,实现了猪舍场景下哺乳母猪准确、快速分割,可为猪只图像分割提供了技术参考。     

益生菌的作用机制及其在母猪生产中的应用

近年来,随着肠道微生态理论的深入,人们逐渐认识到益生菌能够通过抑制病原菌生长、促进营养物质吸收、刺激免疫防御等机制发挥益生作用。作者综述了益生菌的作用机制及其在母猪生产中调节胃肠健康、增强机体免疫、提高繁殖性能和饲料转化率等方面的研究进展,从而为益生菌在母猪生产中的进一步研究和应用提供参考。     

Model Optimization of Litter Size and Genetic Analyses of Model Parameters in Sows

According to two properties of the life cycle and to fluctuation with parities, four mathematical models, the Poisson cycle model, the cubic polynomial model, the modified quadratic polynomial model-I and the modified quadratic polynomial model-II, were used to fit the records of litter size in Jiangquhai sows. From the viewpoint of statistics and biological significance, the modified quadratic polynomial model-I was found to be the optimum model. A single trait animal model and DFREML procedures were further used to estimate the heritability values of optimum model parameters. The results show that the heritability values for the coefficients A and B and the heritability value for the acme of the model pure quadric curve are larger than the heritability value for the litter size. This suggests that selection for model parameters may be more effective than direct selection for litter size.     

Weight loss in overwintering below‐ground parts of Sonchus arvensis under current and temperature‐elevated climate scenarios in Sweden

Weight loss in overwintering below‐ground parts of perennial weeds has been attributed to respiration, but neither its temperature dependence nor its relevance for biomass dynamics under changing climate conditions have been investigated. In two experiments, we quantified weight loss of the perennial weed Sonchus arvensis, by measuring weight changes over time of sprouting roots in dark rooms at temperatures of 4, 8 and 18°C. Dry weight loss rates were 0.47, 0.64 and 1.47% day^?1 at 4, 8 and 18°C, respectively, giving a half‐life time of 149, 110 and 47 days, respectively. A factor by which weight loss rates increase for every 10° rise in temperature (Q₁₀) was equal to about 2.3. Cumulative weight loss may comprise >40% of the below‐ground biomass during overwintering periods. Applying weight loss rates and Q₁₀ to elevated soil temperature projections showed that losses during winter seasons in central Sweden will remain basically constant, the effect of increased weight loss at higher temperatures being balanced by shorter winters. This implies that need for control of S. arvensis in a changing climate will persist, but that shorter winter seasons will provide a longer time window for control of S. arvensis prior to sowing crops.     

玉米平作膜上精播抗旱节水高产栽培技术

为了提高覆膜拜玉米的生产效率,以玉米平作膜上精播抗旱节水高产栽培技术研究为依据,总结了技术模式的主要成效,阐述了高产栽培的栽培技术要点,包括技术内涵、选择机具、整地播种、病虫草防治和收获等方面.     

Assessing the risk of recurrence of porcine epidemic diarrhea virus in affected farms on Jeju Island,South Korea

BackgroundPorcine epidemic diarrhea virus (PEDV) is a swine enteropathogenic coronavirus that has devastated the swine industry in South Korea over the last 30 years. The lack of an effective method to control the endemics has led to a surge in PEDV recurrences in affected farms throughout the country.ObjectivesIn the first step toward establishing systematic monitoring of and active control measures over the swine populations, we constructed an assessment model that evaluates the status of (1) biosecurity, (2) herd immunity, and (3) virus circulation in each of the PEDV-infected farms.MethodsA total of 13 farrow-to-finish pig farms with a history of acute PEDV infection on Jeju Island were chosen for this study. The potential risk of the recurrence in these farms was estimated through on-site data collection and laboratory examination.ResultsOverall, the data indicated that a considerable number of the PEDV-infected farms had lax biosecurity, achieved incomplete protective immunity in the sows despite multi-dose vaccination, and served as incubators of the circulating virus; thus, they face an increased risk of recurrent outbreaks. Intriguingly, our results suggest that after an outbreak, a farm requires proactive tasks, including reinforcing biosecurity, conducting serological and virus monitoring to check the sows’ immunity and to identify the animals exposed to PEDV, and improving the vaccination scheme and disinfection practices if needed.ConclusionsThe present study highlights the significance of coordinated PEDV management in infected farms to reduce the risk of recurrence and further contribute towards the national eradication of PEDV.     

Utilization of milk amino acids by the suckling Iberian piglet

Sixteen pure-bred Iberian (IB) sows were used in two trials to determine the efficiency of utilization of milk protein and amino acid (AA) for growth in suckling piglets. It was hypothesized that there may be one or more strongly limiting essential AA (EAA) responsible for the slow rate of growth of the IB piglet. This AA will show the highest fractional retention. Daily milk yield and composition were determined weekly over a 34-day lactation period. Within each litter, one piglet at birth and four piglets on d 35 of life were slaughtered. The protein content of the IB sow milk was similar to that reported for conventional breeds. However, branched-chain AA, Thr, Pro, Asp and Ala were in concentrations somewhat below the range of literature values and Arg and Met, substantially above it. Milk intake per piglet tended to be greater in Trial 2 (832 vs. 893 g/day respectively; p = 0.066). However, the IB piglets grew at 168 ± 3.3 g/day, irrespective of the trial. The whole-body protein of piglets at weaning and the protein deposited in their body during the lactating period showed very close AA pattern. Among EAA, His and Arg show the highest fractional retentions (g AA retained/g AA ingested) in whole-body tissues (1.019 ± 0.025 and 0.913 ± 0.017 respectively) and also the highest body to milk ratios (1.50 and 1.41 respectively). Gly and Ala presented, among non essential AA, the highest efficiencies of utilization for tissue deposition (1.803 ± 0.057 and 1.375 ± 0.026 respectively) and body to milk ratios (2.75 and 2.12 respectively). These results suggest that the low efficiency of utilization of milk protein and the low rate of gain of the IB suckling piglet can be explained by a marked shortage in His supply, in addition to the suboptimal milk provision of Arg, Gly and Ala.     

不同脂肪源对哺乳母猪繁殖性能及养分消化率的影响

试验旨在研究哺乳母猪日粮中添加不同脂肪源对母猪繁殖性能和饲粮养分消化率的影响。选取第3胎次PIC母猪30头,随机分配到3个处理,即对照组、2%大豆油组和2%脂肪粉组,每个处理10个重复。试验从母猪分娩开始,到仔猪21日龄断奶时结束。结果表明:与对照组相比,脂肪粉组第3周平均日增重(ADG)和第3周窝增重分别提高了26.29%(P<0.05)和23.93%(P>0.05),大豆油组分别提高了19.72%(P>0.05)和17.85%(P>0.05)。且脂肪粉组的提高幅度最大。由此可知,饲粮中添加不同脂肪源可提高饲粮养分消化率,改善哺乳仔猪的生产性能,且脂肪粉优于大豆油。