Genome‐wide association studies reveal additional related loci for fatty acid composition in a Duroc pig multigenerational population

The aim of the present study was to detect quantitative trait loci affecting fatty acid composition in back fat and intramuscular fat in a Duroc pig population comprising seventh‐generation pedigrees using genome‐wide association studies (GWAS). In total, 305 animals were genotyped using single nucleotide polymorphisms (SNPs) array and five selected SNPs from regions containing known candidate genes related to fatty acid synthesis or metabolism. In total, 24 genome‐wide significant SNP regions were detected in 12 traits, and 76 genome‐wide suggestive SNP regions were detected in 33 traits. The Sus scrofa chromosome (SSC) 7 at 10.3 Mb was significantly associated with C17:0 in intramuscular fat, while the SSC9 at 13.6 Mb was significantly associated with C14:0 in intramuscular fat. The SSC12 at 1.0 Mb was significantly associated with C14:0 in back fat and the SSC14 at 121.0 Mb was significantly associated with C18:0 in intramuscular fat. These regions not only replicated previously reported loci containing some candidate genes involved in fatty acid composition (fatty acid synthase and stearoyl‐CoA desaturase) but also included several additional related loci.     

Effects of increased vertebral number on carcass weight in PIC pigs

Variation of the vertebral number is associated with carcass traits in pigs. However, results from different populations do not match well with others, especially for carcass weight. Therefore, effects of increased vertebral number on carcass weight were investigated by analyzing the relationship between two loci multi‐vertebra causal loci (NR6A1 g.748 C > T and VRTN g.20311_20312ins291) and carcass weight in PIC pigs. Results from the association study between vertebral number and carcass weight showed that increased thoracic number had negative effects on carcass weight, but the results were not statistically significant. Further, VRTN Ins/Ins genotype increased more than one thoracic than that of Wt/Wt genotype on average in this PIC population. Meanwhile, there was a significant negative effect of VRTN Ins on carcass weight (P < 0.05). Thus, our results suggested negative effect of increased thoracic number on carcass weight in PIC pigs.     

菜籽粕替代豆粕饲养生长肥育猪的效果

试验选用初始体重21.9kg±2.6kg杜×长仔猪72头,随机分配到18个圈栏,每栏2头母猪和2头去势公猪。试验饲粮针对不同蛋白饲料原料设计为三个处理,每个处理设6个重复。体重20～35kg阶段三个处理饲粮的蛋白饲料类型分别为100%豆粕,10%双低油菜粕和90%豆粕,以及10%普通菜子粕和90%豆粕。体重35～60kg和60～90kg阶段三个处理饲粮的蛋白饲料类型相同,分别为100%豆粕,30%双低菜子粕和70%豆粕,以及30%普通菜子粕和70%豆粕。试验检测指标包括三个体重阶段的平均日增重(ADG)、平均日采食量(ADFI)和饲料转化效率(F/G)。试验结果表明,试验猪在体重20～90kg的生长肥育期,F/G(P<0.075)在处理之间比较差异不显著,但ADG(P<0.01)和ADFI(P<0.05)则表现显著差异。100%豆粕、双低菜子粕和普通菜籽粕各处理的ADG和ADFI分别为907g和2.65kg,831g和2.44kg,以及808g和2.41kg。     

群养猪侵略性行为的深度学习识别方法

为了解决因传统机器视觉和图像处理方法的局限性以及复杂的猪体姿态和猪舍环境导致对群养猪侵略性行为识别的有效性、准确率较低的问题,该文基于深度学习的方法,提出使用3DCONV的群养猪侵略性行为识别算法-3DConvNet。分3个批次采集18头9.6 kg左右的大白仔猪视频图像,选用第一批次中包含28 d内各个时段的撕咬、撞击、追逐、踩踏4大类,咬耳、咬尾、咬身、头撞头、头撞身、追逐以及踩踏7小类侵略性行为以及吃食、饮水、休息等非侵略性行为共计740段(27114帧)视频作为训练集和验证集,训练集和验证集比例为3:1。结果表明,3DConvNet网络模型在训练集上的识别准确度达96.78%,在验证集上识别准确度达95.70%。该文算法模型对于不同训练集批次的猪只以及不良照明条件下依然能准确识别侵略性行为,算法模型泛化性能良好。与C3D模型进行对比,该文提出的网络模型准确率高出43.47个百分点,单帧图像处理时间为0.50 s,可满足实时检测的要求。研究结果可为猪场养殖环境中针对猪只侵略性行为检测提供参考。     

邻水县生猪生产分析及对策

生猪生产在邻水县农村经济中占有一定地位。本文分析了邻水县生猪生产的历史和现状;阐述了生猪生产与加工业以及人们生活的关系和稳定发展生猪生产的对策。     

炎热条件下助长素对断奶仔猪生产性能及血液指标的影响

在高温和高噪音的不良饲养环境条件下，选择体重１０ｋｇ左右杜浙猪４０头，随机分成四组，即对照组、试验Ⅰ、Ⅱ、Ⅲ组。在同一日粮基础上分别添加０％、０．０５％、０．１０％．０．１５％猪用助长素，以探讨不同浓度的猪用助长素对断奶仔猪的生产性能和部分血液指标的影响。结果表明，添加０．０５％、０．１０％、０．１５％猪用助长素均能明显提高断奶仔猪的日增重，提高饲料利用率。经统计分析，添加０．１５％猪用助长素组猪的日增重与对照组之间存在极显著差异（ｐ＜０．０１）。试验组猪只血液中红细胞总数、血色素和碱性磷酸酶含量也明显高于对照组。添加０．１０％猪用助长素的血液碱性磷酸酶含量与对照组之间存在极显著差异（ｐ＜０．０１）。     

Genetic diversity among some cattle breeds in the Alpine area

Seven autochthonous Italian cattle breeds bred in the alpine area (Aosta Black Pied, Aosta Red Pied, Aosta Chestnut, Oropa Red Pied, Grey Alpine, Rendena and Burlina) were investigated in order to characterise their genetic structure and to study their phylogenetic origin. Two cattle breeds from Germany (Original German Brown and Holstein) and four from Switzerland (Simmental, Herens, Evolene and Brown Swiss) were included in the study in order to determine the genetic diversity existing among Italian local breeds, similar breeds bred on the other side of the Alps and in the well known Holstein.
Seventeen microsatellites, of the internationally accepted panel for the study of cattle biodiversity, were used for the analysis.
Microsatellites were highly polymorphic with a mean number of 5,5 alleles (ranging from 2 to 12 per locus). For each locus, allelic frequencies, heterozygosity (H) and the Polymorphism Information Content (PIC) were computed. The genetic equilibrium according to Hardy–Weinberg was calculated for each population and for each locus. Allele frequencies were used to estimate genetic distances and to draw a phylogenetic tree. The two closest breeds were Aosta Red Pied and Aosta Black Pied, while the two genetically most different were Holstein and Aosta Chestnut. Aosta valley breeds, Evolene and Herens constituted a tight cluster in the phylogenetic consensus tree. Principal component analysis showed a similar pattern for all the alpine breeds, while Holstein and Original German Brown were far away. The genetic differences among breeds were in accordance with their geographical and historical origins.     

Sows infected in pregnancy with porcine respiratory coronavirus show no evidence of protecting their sucking piglets against transmissible gastroenteritis

Eighteen litters of sucking piglets were challenged with one of two strains of transmissible gastroenteritis virus (TGEV). During pregnancy, their seronegative dams had been either inoculated intranasally with porcine respiratory coronavirus (PRCV), inoculated orally with TGEV or left untreated. On the basis of weight gain, clinical signs and survival, no differences in response to challenge was detected when piglets suckled by PRCV inoculated sows were compared with those suckled by uninoculated sows. Such a difference was evident when the litters of sows successfully pre-immunized with TGEV were compared with those of unicoculated or PRCV-inoculated sows. The possibility of transplacental transmission of PRCV was investigated in two litters born to sows that had been inoculated with this virus in late pregnancy. All sixteen live-born piglets were seronegative for the virus at birth and PRCV was not isolated from tissues taken from two stillborn piglets.