Pathological and aetiological studies of multifocal interstitial nephritis in wasted pigs at slaughter

Multifocal interstitial nephritis in pigs has been associated with several infectious agents. The objective of the present study was to investigate several different potential infectious agents associated with "white-spotted" kidneys in pigs suffering from wasting at slaughter (aged 6-8 months). Twenty-nine case kidneys (with a "white-spotted" gross appearance) classified into 3 macroscopic lesional grades, and 15 control kidneys (lacking gross lesions), were obtained from a pig abattoir. Laboratory analyses to detect potential associations with the aforementioned pathological condition with Leptospira spp., porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), porcine reproductive and respiratory syndrome virus (PRRSV), and bacteria, were carried out. Microscopically, interstitial nephritis with a lymphofollicular inflammatory pattern (follicular nephritis) was observed in both case and control kidneys, with a higher frequency seen in the former ones. No leptospires were identified, although antibodies to the Pomona and Bratislava serovars were detected. Some pyogenic bacteria were also isolated from both case and control kidneys. PCV2 nucleic acid was only detected in 1 case kidney. PRRSV antigen was not found in any tested sample. Some pigs were tested positive for PPV by serology. Apparently, none of the studied agents were specifically associated as being the potential cause of the renal lesions in the studied wasted pigs. The fact that these chronic lesions may have been the consequence of a previous infection with one of these studied microorganisms, or more, and eventually with other non-tested infectious agents during the growing-finishing period, cannot be ruled out.     

河南省部分中小型猪场种公猪猪瘟野毒感染的分子流行病学调查

[目的]了解河南省部分中小型猪场公猪精液中猪瘟野毒的感染状况。[方法]应用RT-PCR方法对河南省10个中小型猪场的58份种公猪精液进行了猪瘟野毒感染情况的调查。[结果]7个猪场的猪瘟野毒检测结果呈阳性,占总检测场数的70%;10份精液的猪瘟野毒检测结果呈阳性,样品阳性率为17.24%。[结论]河南省大部分中小型猪场存在种公猪猪瘟野毒感染的现象,且感染状况较为严重。     

中国家猪起源机制蠡测

本文重点阐述了我国家猪起源的两种不同动因——提供肉食与用来祭祀,并简要论述了我国猪类驯化的一般过程。     

呼和浩特市开通养猪场猪附红细胞体病的诊治

2010年3月至2010年6月以来,对呼和浩特市开通养猪场发生的疑似猪附红细胞体病从流行特征、临床症状、病理变化、血液学检查等方面进行了综合诊断,确诊为猪附红细胞体病。该猪场母猪、仔猪、育肥猪共有1674头,发病的和疑似患病的占到28.6%,即478头。通过治疗之后,治愈率达到94.8%(454头),死亡24头,占5.02%。     

Detection of porcine circovirus genotypes 2a and 2b in aborted foetuses from infected swine herds in the State of S?o Paulo,Brazil

Background

Porcine circovirus type 2 (PCV2) has been associated with several disease complexes, including reproductive failure. The aim of this study was to identify the subtypes of PCV2 that are associated with reproductive failure in pigs from the State of São Paulo, Brazil and to investigate co-infections with other infectious organisms.

Findings

Samples of 168 aborted foetuses or mummified foetuses from five farrow-to-finish swine farms known to be infected with PCV2 and located in the State of São Paulo were tested for PCV2 by polymerase chain reaction (PCR). Positive samples were additionally tested for porcine parvovirus (PPV), Leptospira spp. and Brucella spp. by PCR. PCV2 was detected in 18 of the samples (10.7%). PPV, Brucella spp. and Leptospira spp were found in 2, 10 and 0 cases, respectively. Eleven PCV2 strains were sequenced and determined to be either genotype 2a (n = 1) or 2b (n = 10).

Conclusions

The findings indicate that the frequency of PCV2 infections in aborted porcine foetuses from the State of São Paulo is rather low (10.7%) and that co-infection with other pathogens is common and may be involved in PCV2 associated reproductive failure. No repeatable, characteristic amino acid motifs for regions of the PCV2 capsid protein seemed to be associated with abortion in sows.     

中药提高猪肉品质应用上的研究进展

如今受集约化养殖弊端的影响,动物的活动量大量减少。相较于野猪和放养猪的肉质而言,集约化养殖的猪肉品质较差,因此寻找合适的添加剂对集约化养殖的猪肉进行改善显得尤为重要。而中药属于天然药物,具有无残留、无耐药性和低毒副作用等特点,且具有提高肉品质的作用,因此受到越来越多的学者的关注。文章主要介绍了中药的特点、功能及其对猪肉品质的影响和作用机理。     

新型关中黑猪胴体性能和肉质性能研究

试验随机选取6头关中黑猪育肥猪进行屠宰,测定其屠宰性能和肉质性状,为关中黑猪的提纯复壮和保种利用提供指导依据.结果表明,屠宰体重为95.29 kg时,屠宰率为74.61％,腿臀比例为27.23％;瘦肉率和脂肪率分别为48.96％,33.96％,背膘厚为37.46mm,眼肌面积为24.20 cm2.关中黑猪肉色评分3.53,大理石纹3.75;肌内脂肪含量为5.2％,肌纤维直径为64.8μm;关中黑猪肌内脂肪酸主要有十六酸和十八酸组成,饱和脂肪酸含量、单不饱和脂肪酸和多不饱和脂肪酸含量分别为41.43％,55.22％,3.37％;关中黑猪背最长肌氨基酸中必需氨基酸占34％,鲜味氨基酸占39％.试验结果提示,关中黑猪胴体性能的一些指标较早期研究有所退化,但仍保持了其肉质优良的特性.     

Evaluation of protection conferred by a Salmonella Typhimurium inactivated vaccine in Salmonella-infected finishing pig farms

The efficacy of an inactivated S. Typhimurium vaccine administered to pigs at the beginning of the fattening period was evaluated in four clinical trials (trials A, B, C and D). Faecal shedding and the systemic antibody response during fattening, as well as, the cecal contents and mesenteric lymph nodes collected after slaughtering were used to assess the outcome. Salmonella shedders prevalence in the control groups was six times higher than in the treated groups in trials A and D, both herds infected by S. Typhimurium. The risk of positive pens was also four or five times higher for the pens housing control pigs in trials A and C. Lower prevalence of Salmonella was observed in the slaughter samples from the vaccinated pigs in trial D and in the cecal content samples in trial A, when just the S. Typhimurium results were compared. The results suggest the effective homologous protection of the vaccinated pigs; however, the high humoral response elicited in the vaccinated pigs complicates their use in farms under serological surveillance programmes.     

In utero exposure to the anti-androgen flutamide influences connexin 43 and β-catenin expression in porcine fetal gonads

Recent reports have indicated a role of cell-to-cell interactions during gonadal development and functions. Numerous reports indicate that fetal hormonal disruption induces abnormalities in the developing reproductive system and, therefore, may interfere with reproductive functions later in adult life. Hence, this study investigated the effect of androgen deficiency during late prenatal periods on the gap junction-associated connexin 43 (Cx43) and the adherens junction-associated β-catenin expression in the fetal porcine gonads. Thus, pregnant gilts were injected with anti-androgen flutamide (for 7 d, 50 mg/kg BW per day) or corn oil (control groups) starting at 83 (GD90) or 101 (GD108) gestational day. On GD90 and GD108 the fetuses were excised and fetal gonads were obtained. To assess Cx43 and β-catenin expression real-time PCR and immunohistochemistry were performed. In fetal testes, Cx43 was localized between Leydig cells, whereas β-catenin was observed mainly within the seminiferous tubules. In fetal ovaries, Cx43 was detected between interstitial cells and between granulosa cells of forming follicles, whereas β-catenin was found within egg nests, in oocytes' membrane, and in granulosa cells of forming follicles. Immunohistochemistry showed decreased Cx43 and β-catenin expression in fetal gonads from flutamide-treated pigs compared with respective controls. However, the ovaries from animals treated with flutamide on GD108 showed increased Cx43 expression. The changes of Cx43 and β-catenin expression after prenatal flutamide treatment were confirmed at the mRNA level. These findings suggest that androgen deficiency during late gestation may lead to disturbed intercellular interactions in fetal porcine testes affecting testicular functions, as well as impaired follicular formation in fetal ovaries. Our results further signify the role of androgens in the regulation of cell-to-cell interactions within fetal porcine gonads.     

Genetic variation of in vivo muscle glycerol,glycogen, and pigment in Danish purebred pigs

Heritability values of glycerol, glycogen and pigment concentrations measured on muscle biopsy samples from longissimus dorsi obtained from 85?kg boars of Danish purebred pigs (Landrace, Yorkshire, and Duroc) and their genetic correlations to performance and meat quality traits were calculated. The heritability values of glycogen, pigment, and glycerol were 0.38±0.02, 0.17±0.02, and 0.065±0.016, respectively. Glycogen was negatively related to the feed conversion ratio (FCR) (r _g =?0.25±0.06) and ultimate meat pH (r _g =?0.41±0.04), and positively to the carcass meat percentage (r _g =0.35±0.04), L* (lightness of meat, r _g =0.32±0.04) and a* (redness of meat, r _g =0.12±0.03). Pigment was positively related to the FCR (r _g =0.12±0.05), the meat percentage (r _g =0.28±0.05), and a* (r _g =0.59±0.04), and negatively to the L* (r _g =?0.46±0.06). The concentrations of pigment and glycogen (r _g =0.27±0.05) were interrelated. Based on the heritability values and the signs of the genetic correlations the present data suggest that it is possible to select for higher ultimate pH and improved colour by selection for either lower muscle glycogen or higher pigment concentration, respectively. However, the positive genetic correlation between these two traits may restrict the efficiency of simultaneous selection for lower glycogen and higher pigment. All genetic parameter estimates presented are calculated across three purebreds. Values for each breed are warranted for use in pig production. However, this requires more animals per breed.