In growing pigs, chlortetracycline induces a reversible green bone discoloration and a persistent increase of bone mineral density dependent of dosing regimen

We studied in growing pigs the effects of exposure to dietary chlortetracycline on bone mineral density (BMD) and bone color. Pigs were randomly allocated to a drug-free diet (n = 48) or a diet fortified with 800 ppm of chlortetracycline, starting either at 28- or 84-d of age, and for either a 28- or 56-d duration (n = 16 pigs/group). The lumbar vertebral discoloration and BMD of randomly chosen pigs were evaluated at 28-d intervals up to 168-d of age. The odds of bone discoloration increased with dosing duration and age at treatment onset, and decreased with the withdrawal time and age at treatment onset interaction (p ? 0.001). The measured trabecular BMD linearly increased with age and squared treatment duration (p ? 0.005). Therefore, TC-induced bone discoloration is reversible, and may be prevented with proper dosing regimen design. Moreover, TC induces a persistent increase on BMD that could be detected with quantitative computed tomography.     

Virulence genes and plasmid profiles in Rhodococcus equi isolates from domestic pigs and wild boars (Sus scrofa) in Brazil

The virulence genes and plasmid profiles of 23 Rhodococcus equi isolates from 258 lymph nodes from domestic pigs (129 nodes with lesions and 129 without lesions) and 120 lymph nodes from slaughtered wild boars (60 nodes with lesions and 60 without) were characterized. R. equi was obtained from 19 lymph nodes of domestic pigs, 17 with, and two without lesions, and from four lymph nodes with lesions, from wild boars. The 23 isolates were tested for the presence of vapA and vapB genes, responsible for the 15–17 and 20 kDa virulence-associated proteins, respectively, by PCR in order to characterize as virulent (VapA), intermediately virulent (VapB) and avirulent. Plasmid DNAs were isolated and analyzed by digestion with restriction endonucleases to estimate size and compare their polymorphisms. Of the 19 domestic pigs strains, seven (36.8%) were avirulent and 12 (63.2%) were intermediately virulent, with the intermediately virulent isolates being plasmid types 8 (8 isolates), 10 (2 isolates), 1 (1 isolate) and 29 (1 isolate). The plasmid type of four strains isolated from wild boars was also intermediately virulent type 8. None of the domestic pigs and wild boar isolates showed the vapA gene. These findings demonstrate a high occurrence of plasmid type 8 in isolates from pigs and wild boars, and the similarity of plasmid types in the domestic pigs, wild boars and human isolates in Brazil.     

Pigs as an experimental model for systemic Mycobacterium avium infectious disease

Mycobacterium avium complex (MAC) is an opportunistic pathogen in AIDS patients and pigs, and causes dissemination through primary intestinal lesions. However, its pathogenesis is not well understood. In this article, we hypothesize that pigs can provide a suitable experimental model of disseminated MAC disease. We compared the initial route of infection, the characteristics of the pathogenic strains, the immunological status of the hosts, and the histological characteristics. The route of infection and infective strains are similar in AIDS patients and pigs. Pigs can respond to infection by the formation of systemic epithelioid granuloma with sufficient cell-mediated immunity. However, there are differences in immunological status and histological features between AIDS patients and pigs. Therefore, pigs might be used as an appropriate animal model because of their good cell mediated immunity triggered by systemic mycobacterial infection. In conclusion, MAC infections in AIDS patients and pigs show similarities in terms of the initial route of infection and the genetic characteristics of the pathogenic strains.     

肌肉苹果酸酶活性与猪肉品质关系的研究

[目的]探讨肌肉苹果酸酶活性与猪肌肉品质的关系,为提高猪肌肉品质提供理论依据。[方法]选取3个不同品种的猪（鄂西黑猪、长野鄂杂交猪和长大二元杂交猪）,比较了肌肉苹果酸酶活性以及肉质性状之间的差异。[结果]结果表明,鄂西黑猪的肌肉苹果酸酶活性和肌内脂肪显著高于长野鄂（三元）杂交猪和长大二元杂交猪（P〈0.05）;长大二元杂交猪的肌肉pH2值、滴水损失和剪切力显著高于鄂西黑猪（P〈0.05）。[结论]猪肌肉苹果酸酶活性对猪肉品质存在一定的影响。其中,肌肉苹果酸酶活性与肌内脂肪含量呈显著正相关,与肉色呈正相关,而与滴水损失和剪切力呈显著负相关。     

海南猪杂交效果及海南猪H-FABP基因和MyoG基因5′上游区域的遗传变异研究

测定了海南猪、海南猪母猪与杜洛克公猪杂交后代的胴体性状、肉质性状,并对脂肪酸结合蛋白(H-FABP)和肌细胞生成素(MyoG)基因的5′上游区域的遗传变异进行了分析。结果表明:杂交黑猪与其母本海南猪相比,活体重、胴体重、屠宰率、胴体长、瘦肉率均有提高,且差异显著(P0.05),表现出较好的杂种优势;骨率、皮率降低,脂肪沉积性能提高,而眼肌面积、皮厚变化不大。另外,海南猪与杂交黑猪肉质均符合优良肉质标准,杂交黑猪肉在滴水损失、大理石纹、水分、粗蛋白含量等方面优于海南猪,表现出较好的杂种优势。海南猪H-FABP基因5′上游区域和MyoG基因5′上游区域遗传变异的基因型和等位基因频率,为海南猪优良肉质性状的形成提供了遗传学依据。     

浅谈动物福利与我国现代养猪工艺模式

近年来,我国的猪肉及生猪产品在对外贸易中屡屡受到抵制,主要原因是畜产品的质量问题和动物福利没有得到重视。这一问题将在很长一段时间内影响并制约着我国养猪业的发展和在国际上的竞争力。简要分析阐述了我国目前广泛使用的养猪工艺模式、存在的问题及如何通过改善养猪工艺来提高动物的福利,从根本上改善猪肉产品的质量,为保障猪肉产品安全,提高国际贸易水平提供全新思路。     

Characterization of ileal bacterial microbiota in newly-weaned pigs in response to feeding lincomycin, organic acids or herbal extract

The changes of ileal bacterial microbiota in pigs during the first 2 weeks post-weaning in response to feeding lincomycin, organic acids or herbal extract were characterized using 16S rRNA gene-based PCR-denaturing gradient gel electrophoresis (DGGE) profiling, DNA sequencing, and real-time PCR (QPCR) techniques. Both time post-weaning and the dietary treatments resulted in a shift of the microbiota composition. While time post-weaning mostly influenced Clostridium group, the feed additives increased the population of Lactobacillus and related lactic acid bacteria by ≥ 3-fold.     

In vitro dose–response of carvacrol, thymol, eugenol and trans-cinnamaldehyde and interaction of combinations for the antimicrobial activity against the pig gut flora

In vitro simulations of the gastric and small intestinal fermentation with varying doses of carvacrol, thymol, eugenol and trans-cinnamaldehyde and binary combinations thereof were carried out to calculate dose–response equations for the antimicrobial effect against the main pig gut flora components. Interaction effects were evaluated following the isobole method. In gastric simulations eugenol and trans-cinnamaldehyde showed clearly less inhibitory activity towards lactobacilli than carvacrol and thymol, which could also be observed in the small intestinal simulations. The minimum concentration for carvacrol, thymol, eugenol and trans-cinnamaldehyde in small intestinal simulations to reduce the number of total anaerobic bacteria compared to control with a probability of 99.7% was 255, 258, 223 and 56 mg/l respectively. This strong activity of trans-cinnamaldehyde was due to its effect against coliform bacteria; a dose of 104 mg/l gave a reduction of 1 log CFU/ml vs. 371, 400 and 565 mg/l for carvacrol, thymol and eugenol respectively. Few combinations demonstrated synergism; most mixtures showed zero interaction or antagonism. Only carvacrol + thymol was slightly synergistic.     

药食同源中草药栀子及其在现代养猪生产中的应用前景

文章考证了山栀子的药用性状及水栀子的染色功效以及它们的形状区别与生长环境,综述了山栀子的药理作用及其研究进展。文章最后指出,基于栀子的性味、归经,药用功效,生物活性,特别是富含优质膳食纤维,又具有抗疲劳、抗氧化的生物活性,在猪尤其在母猪的健康养殖中,具有广阔的应用前景。