托佩克(Topigs)种猪日增重与背标厚选择效果分析

文章对托佩克(Topigs)3个品系5年的日增重和背膘厚性状测定数据作选择效果分析.在对两个性状作遗传参数计算的基础上,明确了这两个性状的遗传力为中等以上,3个品系稍有差异(A系日增重和背膘厚遗传力分别为0.68和0.61;B系分别为0.67和0.48,E系分别为0.48和0.38),同一性状存在阶段性的差别.以此为基...     

不同净能水平日粮对育肥猪生长性能、背膘厚度及眼肌面积的影响

试验研究不同净能水平日粮对育肥猪生长、背膘及眼肌面积的影响.选择420头(38.5±0.5) kg丹系三元育肥猪,随机分为5组,每组6个重复,每个重复14头猪,公、母各半.试验A、B、C、D、E组饲粮净能水平分别为9.84、10.05、10.26、10.46和10.67MJ/kg,预试期7d,正式试验期97 d.结果 ...     

GxE interactions for growth and carcass leanness: Re-ranking of boars in organic and conventional pig production

The objective of this study was to evaluate genotype by environment interactions for growth rate and carcass leanness in organic and conventional pig production environments. Organic breeding values for fattening traits were estimated for 37 Hampshire AI-boars based on slaughter records registered for 1805 crossbred offspring raised in an organic environment. The offspring were born and raised in herds certified for organic production. The statistical model included the fixed effects of sex, litter size at 2 weeks and herd. It also included the random effects of herd-year-season, birth litter and animal. Conventional breeding values for the same boars were captured from the breeding organization’s genetic evaluation. In the organic environment h² was estimated to 0.30 and 0.37 for growth rate and carcass leanness, respectively (r_g = − 0.11). Spearman rank correlations between organic and conventional breeding values, based on 29 boars with ≥ 20 progenies, were 0.48 for growth rate and 0.42 for carcass leanness. Both correlations were significantly different from 0 and 1. In conclusion, the results of the present study indicate weak genotype by environment interactions for both growth rate and carcass leanness in organic and conventional pig production environments, and there is some re-ranking of boars’ breeding values between environments.     

利用发酵饲料养猪效果好

发酵饲料作为新型环保型饲料,具有适口性好,活菌含量高,营养更全面,绿色无残留等特点。利用其养猪能够调节猪肠道的微生态平衡,提高饲料利用率,降低饲养成本,增强免疫功能,减少发病死亡,提高生产性能,改善酮体品质,减少环境污染,是饲料“禁抗”后的最佳替代物,代表着绿色健康、生态环保、节粮型畜牧业的发展方向,有很高的应用价值和广阔的市场前景。     

Genetic and environmental factors affecting ultrasound measures of longissimus muscle area and backfat thickness in Nelore cattle

The aim of the present study was to evaluate the genetic and environmental factors affecting records of longissimus muscle area (LMA) and backfat thickness (BF) obtained between the 12th and 13th ribs, and rump fat thickness (RF) between the hook and pin bones, measured by real-time ultrasound in Nelore cattle. Also, weight records of 22,778 animals born from 1998 to 2003, in ten farms across six Brazilian states were used. Carcass traits as measured by ultrasound of the live animal were recorded from 2002 to 2004 in 2590 males and females with ages varying from 450 to 599 days. Fixed models including farm, year and season of birth, sex and type of feed effects, and the covariates age of dam (AOD) and age of animal at measurement were used to study the effect of environmental factors on these traits. The genetic parameters for LMA, BF and RF were estimated with two and three-trait animal models with 120-day weights using a restricted maximum likelihood method. All environmental effects significantly affected carcass traits, with the exception of year of birth for BF and RF and AOD for LMA. The heritability estimates for LMA, BF and RF were 0.35, 0.51 and 0.39, respectively. Standard errors obtained in one-trait analyses were from 0.07 to 0.09. Genetic correlation estimates between LMA and the two traits of subcutaneous fat were low (close to zero) and 0.74 between BF and RF, indicating that the selection for LMA should not cause antagonism in the genetic improvement of subcutaneous fat measured by real-time ultrasound.     

The welfare of finishing pigs in two contrasting housing systems: Fully-slatted versus straw-bedded accommodation

Four consecutive studies were carried out over a 3-year period to assess the health and welfare implications of housing finishing pigs in either fully-slatted or straw-bedded accommodation. In each study, 1024 (Large White × Landrace) × Large White pigs, housed in pen groups of 32, were fed ad libitum from 34 kg to slaughter at 104 kg live weight. Eight batches of pigs were received in each study and allocated alternately to fill one room of four pens in each house. Data were collected on a range of welfare parameters. Lameness (P < 0.001) and bitten tails (P < 0.001) were more prevalent health problems in the fully-slatted system, whilst in the straw-bedded system pigs showed more respiratory (P < 0.01) and PMWS-type symptoms (P < 0.01). Acute phase protein titres at slaughter were higher in pigs from the fully-slatted system (P < 0.001). Skin lesion score did not differ between systems; however, bursitis was more severe in pigs in the fully-slatted system (P < 0.001). Pigs in the straw-bedded system had poorer hygiene scores (P < 0.001), but the magnitude of this difference varied between studies depending on season. Pigs with straw were more active (P < 0.001), spending a large proportion of time manipulating straw. In the absence of straw, pigs spent more time in behaviour directed at other pigs (P < 0.001) and the pen components (P < 0.001). Post-slaughter assessment showed no system differences in lung lesions and cardiac scores, or osteochondrosis. Pigs with straw had more severe toe erosions on the foot (P < 0.001), whilst pigs without straw had more severe sole (P < 0.001) and heel erosions (P < 0.001). Gastric lesion scores were lower in the fully-slatted system (P < 0.001). The results show both advantages and disadvantages to each of the housing systems for pig welfare.     

The effect of grassmeal and alfalfa meal on daily gain, thickness of backfat and on the esophagogastric region in bacon pigs.

In pigs dietary factors often are involved as causes of lesions in pars esophagea of the stomach. In experiments the primary purpose of which was to clarify the effect of grassmeal or alfalfa meal on growth, feed efficiency and carcass quality in bacon pigs, an influence of these feedstuffs on the growth rate and degree of esophagogastric lesions was detected. Pigs with these lesions had as an average a lower daily gain and less backfat than pigs without lesions.     

Variation in the expression of Hsp27, αB-crystallin mRNA and protein in heart and liver of pigs exposed to different transport times

Twenty pigs were randomly divided into four groups of five pigs each (not transported – control, 1, 2 and 4 h of transportation). A significant increase of ALT, AST and CK in the blood serum and acute parenchyma cell lesions were observed and those were characterized by acute degenerations in the heart and liver. Hsp27 expression levels increased significantly in the heart after 2 h and in the liver after 4 h of transportation, accompanying with the hsp27 mRNA increasing significantly in the heart and liver after 1 h of transportation. αB-crystallin expression levels were fluctuant (not significantly) in the heart and liver during transporting, however, αB-crystallin mRNA increase notably in the heart after 1 h and decrease significantly in the liver at 1 and 2 h of transportation, respectively. In conclusion, the cellular damage to the heart and liver is highest after 1 h of transportation, Hsp27 and αB-crystallin play dissimilar roles and show tissue-specific response in different tissues during transportation.     

Comparison of scratching behaviour of growing pigs with sarcoptic mange before and after treatment, employing two distinct approaches

In a closed pig breeding and finishing herd suffering from sarcoptic mange, two selected groups of pigs were filmed during a period of 10 days before and after treatment. The observation always commenced each hour and lasted for 15 min. Before treatment, observations was done round the clock, after treatment from 8:00 to 22:15.

Before treatment the pens were stocked with 11 (pen A) and 10 (pen B) growing pigs (Large White × Landrace sows; 5 months old) with an average weight of 70 kg examined for sarcoptic mange by skin scrapings and ELISA. The animals had never been treated with an acaricide or endectocide before.

After 10 days, the pigs were treated twice (18 days interval) with Dectomax^® 1% solution for pigs (Pfizer, Austria) at a dose of 0.3 mg Doramectin i.m./kg body weight. After treatment, seven pigs were observed in both pens.

Most scratching actions both before (83.1%) and after (94.5%) treatment were of one to 10 s. After treatment, the 10 s-scratching episodes decreased by 67.3% (from 21.2 to 6.9 mean SRE/pig), and the scratching actions of longer than 10 s by 91.7% (from 4.3 to 0.4 mean SRE/pig), such that the latter could be observed only occasionally after treatment.

A distinct increase in scratching activity both before and after treatment could be observed primarily between 10:00 and 15:00. Significant differences of scratching and rubbing activity between before and after treatment could also be seen at midday.

The interpretation of the scratching index values before and after the treatment were carried out according to Cargill et al. [Cargill, C., Davies, P., Carmichael, I., Hooke, F., Moore, M., 1994. Treatment of pigs with doramectin to control sarcoptic mange. Proceedings of the 13th IPVS Congress, Bangkok, Thailand, p. 238] with the maximum and minimal limiting values specified in the literature, and compared with calculations using the method described by Hollanders et al. [Hollanders, W., Harbers, A.H.M., Huige, J.C.M., Monster, P., Rambags, P.G.M., Hendrikx, W.M.L., 1995. Control of Sarcoptes scabiei var. suis with ivermectin: influence on scratching behaviour of fattening pigs and occurence of dermatitis at slaughter. Vet. Parasitol. 58, 117–127].

Depending on the methods used and the limiting values set, 6.7–34.6% of the observations before and 2.0–17.3% of the observations after treatment revealed a “strong evidence of mange” or a “suspicion of mange”. All other observations indicated that the pigs were free from mange.     

Protective efficacy of a live attenuated Mycoplasma hyopneumoniae vaccine with an ISCOM-matrix adjuvant in pigs

An attenuated Mycoplasma hyopneumoniae vaccine that requires intrathoracic administration is commercially available for use against mycoplasmal pneumonia in China. Given the limitations of such a route of administration, this study was undertaken to assess the capacity of an ISCOM-matrix adjuvant to enhance immunogenicity following intramuscular use. Immune responses in pigs following vaccination and subsequent intra-tracheal bacterial inoculation were examined using lymphocyte proliferation, serology and mucosal IgA in both nasal and saliva swabs.Vaccination induced clear lymphocyte proliferation, but only slight serum antibody responses although these were significantly increased following experimental infection. Mucosal IgA was not detected in either nasal or salivary secretions. Following bacterial challenge, animals vaccinated with the adjuvant-containing live vaccine exhibited less severe pulmonary lesions (median score 3.67) than unvaccinated pigs (median score 13.58). The degree of ciliary loss on the respiratory tract surface was reduced in vaccinated pigs compared with experimentally infected controls. The findings indicated that the adjuvant vaccine administered IM provided protection against experimentally induced mycoplasmal pneumonia and could have commercial potential.     

Gut health:The results of microbial and mucosal immune interactions in pigs

There are a large number of microorganisms in the porcine intestinal tract. These microorganisms and their metabolites contribute to intestinal mucosal immunity, which is of great importance to the health of the host. The host immune system can regulate the distribution and composition of intestinal microorganisms and regulate the homeostasis of intestinal flora by secreting a variety of immune effector factors, such as mucin, secretory immunoglobulin A (sIgA), regenerating islet-derived III (RegIII)γ, and defensin. Conversely, intestinal microorganisms can also promote the differentiation of immune cells including regulatory T cells (T_reg) and Th17 cells through their specific components or metabolites. Studies have shown that imbalances in the intestinal flora can lead to bacterial translocation and compromised intestinal barrier function, affecting the health of the body. This review focuses on the composition of the pig intestinal flora and the characteristics of intestinal mucosal immunity, discusses the interaction mechanism between the flora and intestinal mucosal immunity, as well as the regulation through fecal microbiota transplantation (FMT), dietary nutritional composition, probiotics and prebiotics of pig intestinal microecology. Finally, this review provides insights into the relationship between intestinal microorganisms and the mucosal immune system.     

Morphologic and phenotypic characteristics of myocarditis in two pigs infected by foot-and mouth disease virus strains of serotypes O or A

Myocarditis is often cited as the cause of fatalities associated with foot-and-mouth disease virus (FMDV) infection. However, the pathogenesis of FMDV-associated myocarditis has not been described in detail. The current report describes substantial quantities of FMDV in association with a marked mononuclear inflammatory reaction, interstitial edema and cardiomyocyte degeneration in the myocardium of two pigs that died during acute infection with either of two different strains of FMDV. Despite similar clinical progression, there was a marked variation in morphological characteristics of myocarditis with a significant difference in intensity of myocardial inflammation between the two cases. Phenotypic characterization of leukocyte populations revealed that in both cases, the inflammatory infiltrate consisted mainly of combinations of CD172a+, CD163+ and CD44+ cells, with a distinct subset of CD8+ cells, but with consistent lack of detection of CD3+ and CD21+ cells. This suggests that the FMDV-associated acute myocardial inflammation in the two observed cases consisted mainly of leukocytes of monocyte lineage, with a distinct population of CD8+ cells which, based on lack of CD3 detection in serial sections, are likely to represent NK cells.     

Effects of porcine leptin receptor gene polymorphisms on backfat thickness,fat area ratios by image analysis,and serum leptin concentrations in a Duroc purebred population

The leptin receptor (LEPR) gene is considered a candidate gene for fatness traits. It is located on SSC 6 in a region in which quantitative trait loci (QTLs) for backfat thickness (BF), fat area ratios, and serum leptin concentration (LEPC) have previously been detected in a Duroc purebred population. The objectives of the present study were to identify porcine LEPR polymorphisms and examine the effects of LEPR polymorphisms on fatness traits in this same population. The Duroc pigs (226 to 953 pigs) were evaluated for BF, fat area ratios using image analysis, and LEPC. A total of seven single nucleotide polymorphisms (SNPs) in the full‐length LEPR coding region were identified in pigs from the base population. Four non‐synonymous SNPs of the LEPR gene and 15 microsatellite markers on SSC 6 were then genotyped in all pigs. During candidate gene analysis, we detected significant effects of the non‐synonymous SNP c.2002C>T in exon 14 on all traits. In fine mapping analysis, significant QTLs for BF, fat area ratios, and LEPC were detected near the LEPR gene in the same region. These results indicated that the c.2002C>T SNP of LEPR has a strong effect on BF, fat area ratios and LEPC.     

The effect of antimicrobial growth promoter withdrawal on the health of weaned pigs in Finland

The use of the antimicrobial growth promoters (AGPs) carbadox and olaquindox has been banned in the European Union (EU) since September 1999. We studied the effects of the withdrawal on the health of weaned piglets on two types of piglet-producing farms (farrowing herds and farrow-to-finish herds) from the different regions of Finland. Farms with no major problems with post-weaning diarrhoea were selected for the study to better evaluate the effect of AGPs alone. Data on production, medication and incidence of diarrhoea were collected from 73 farms during 1 year after the withdrawal. On 29 of these farms, the data collection began 4 months before the withdrawal.

The health management of the pigs is considered good in Finland, and special attention has been paid to improve the husbandry practices and management of the farms. Eighty-two percent of the farms in the study were free of both Mycoplasma hyopneumoniae and Sarcoptes scabiei infection. Brachyspira hyodysenteriae infection was not detected in any of the farms. The median number of sows in the herds was 56.0 (IQR = 43.0; 72.5) in 2000.

The level of antimicrobial use in each herd was classified as low, moderate and high when the percentage of weaned pigs treated for diarrhoea during a 4-month period was 0–5%, 6–19% and ≥20%, respectively. Only on four herds (14%), there was an increase in the level of antibiotic use after the AGP withdrawal, when seasonally corresponding 4-month periods were compared. Fourty-one percent of these 29 farms were categorized as low users of antimicrobials, 38% as moderate users and 21% as high users.

The level of antimicrobial use for treatment of diarrhoea after weaning (and the incidence of diarrhoea in weaned piglets) did not increase significantly after the withdrawal of AGPs from weaner feeds according to farmers’ evaluations. In this study, the Escherichia coli infection was the most-common cause of diarrhoea in weaned pigs. The age at weaning did not change after the withdrawal of AGPs.     

广东地区5种优势血清型猪大肠杆菌的外膜蛋白型研究

对从广东地区部分猪场分离的大肠杆菌进行血清型鉴定后,选取优势血清型O₉、O₂₆、O₆₀、O₁₀₁和O₁₀₇的8个致病性较强的分离株,采用超声波裂解、N-十二烷基肌氨酸钠处理和超速离心技术提取大肠杆菌的外膜蛋白（OMP）,利用SDS-PAGE电泳进行OMP分型。结果8个菌株共有3个OMP型（Ⅰ～Ⅲ型）,其中O₂₆、O₁₀₁、O₁₀₇型的3个分离株的外膜蛋白型由1条带组成,为OMP-Ⅰ型;O₆₀、O₁₀₁、O₁₀₇型的4个分离株的外膜蛋白型由2条带组成,为OMP-Ⅱ型;O₉型的1个分离株的外膜蛋白型由3条带组成,为OMP-Ⅲ型。这表明,优势血清型O₉、O₂₆、O₆₀、O₁₀₁、O₁₀₇的分离株OMP型不单一;同一血清型的分离株,存在不同OMP型;而不同血清型的分离株却可有相同的OMP型。     

The outer membrane protein type of five dominant Eschedchia coli serotypes in pigs in Guangdong area

对从广东地区部分猪场分离的大肠杆菌进行血清型鉴定后,选取优势血清型09、026、060、0100和O107的8个致病性较强的分离株,采用超声波裂解、N-十二烷基肌氨酸钠处理和超速离心技术提取大肠杆菌的外膜蛋白（0MP）,利用SDS-PAGE电泳进行OMP分型。结果8个菌株共有3个OMP型（I～III型）,其中026。、0101、0107型的3个分离株的外膜蛋白型由1条带组成,为0MP—I型;060、0101、0107型的4个分离株的外膜蛋白型由2条带组成,为OMP—II型;09型的1个分离株的外膜蛋白型由3条带组成,为OMP-Ill型。这表明,优势血清型09、O26、0101、O107的分离株OMP型不单一;同一血清型的分离株,存在不同OMP型;而不同血清型的分离株却可有相同的OMP型。