常见霉菌毒素对母猪繁殖性能的影响及当前防控措施的进展

霉菌毒素是霉菌在生长繁殖过程中,受环境影响产生的次级代谢产物。霉菌毒素对人和动物来讲,不能被生命体吸收、利用或分解,会产生巨大的类毒性反应。常见的霉菌主要包括:镰刀菌属、曲霉菌属、青霉菌属和麦角菌属等。其产生的毒素主要有:黄曲霉菌毒素、赤霉烯酮族毒素、呕吐毒素、单端孢霉毒素、赭曲霉毒素和麦角毒素等。畜牧业所饲养的畜禽种类,以猪最为敏感,能够造成猪的生长抑制、免疫机能抑制和繁殖性能下降等。尤其对母猪的繁殖性能,造成的危害最为严重。是降低母猪繁殖性能,间接危害新生仔猪品质等重要因素之一。     

霉菌毒素引起母猪繁殖障碍的诊治

霉菌毒素中毒引起母猪繁殖障碍的主要原因是由于猪只采食了发霉腐烂的饲料后引起的一种中毒性疾病,并且在各种年龄、品种的猪都可引起发生。妊娠母猪和小乳仔猪更为敏感。妊娠母猪和商品猪均从肝脏受到侵害。表现为肝脏充血和出血,在肝脏、肾脏实质变性、坏死导致肝细胞变性、胆管和肝细胞增生、怀孕母猪流产、公猪产生包皮炎和阴茎肿胀。     

产后母猪及新生仔猪的护理

产后母猪及新生仔猪的护理 ,是养猪日常生产经营中存在的一个较大的问题 ,它既涉及到母猪机体恢复的快慢和母猪是否能继续正常繁殖的问题 ,又涉及到仔猪的日后生长发育。根据笔者多年经验 ,现就几个方面谈谈产后母猪及新生仔猪的护理。1　产后母猪的护理母猪在分娩过程中 ,整个机体发生剧烈的变化 ,机体抵抗力减弱 ,很容易受到细菌及病毒的侵袭。因此 ,对于产后及流产后的母猪应重视护理工作 ,以促使母猪尽快恢复正常 ,并防止发生产后疾病。母猪产后外阴部的清洁。用消毒溶液清洗母猪的外阴部、尾巴及后躯。产后阴门松弛 ,卧下时阴道黏膜容…     

治病先治肝——论仔猪腹泻和猪霉菌毒素中毒

文章分析了仔猪腹泻的原因,认为仔猪腹泻与母猪肝炎有关,且母猪肝炎的因为毒素过多无法代谢以致病变,应从保肝出发,包母猪从而保仔猪。文章给出了保肝方案,和猪霉菌毒素病例的处理方案。     

霉菌毒素脱毒降解酶对母猪生产性能的影响北大核心

试验旨在探讨霉菌毒素脱毒降解酶对母猪生产性能的影响。选取同一批次、遗传背景、妊娠胎次和预产期相近的妊娠母猪300头,随机分为2组,每组5个重复,每个重复30头母猪。对照组为基础日粮,试验组在基础日粮中添加0.1%霉菌毒素脱毒降解酶。试验期150 d。结果表明,与对照组相比,试验组母猪情期受胎率、配种分娩率、产仔数差异均不显著(P>0.05);试验组哺乳仔猪的出生均重、断奶窝重、断奶均重、窝增重及个体增长均显著提高(P<0.05)。研究表明,添加霉菌毒素降解酶能够改善繁殖母猪健康和泌乳水平,提高哺乳仔猪的生长性能。     

提高母猪繁殖力的技术措施

如何提高母猪繁殖力、综合采取措施、仔猪的下痢、腹泻、选择优良杂交母猪、适时配种、淘汰繁殖性能差的母猪,提高群体繁殖水平、加强种公猪和妊娠母猪饲养管理、做好接产工作和哺乳母猪的饲养管理、做好仔猪腹泻的预防与治疗工作.     

母猪繁殖障碍综合征及防治

母猪繁殖障碍综合征是繁殖母猪的一种重要疾病．其临床症状主要表现为母猪不孕、流产、胚胎早期死亡,产木乃伊胎、畸形胎、弱仔及少仔等。病因分为先天性、机能性、营养性、机械性和疾病性,其中以传染性疾病危害最大,常呈大面积地方性和流行性感染．导致大量妊娠母猪流产和新生仔猪死亡,给规模猪场造成了巨大的经济损失。     

母猪繁殖性能低下原因及对策

<正>近年来,我国的母猪少胎、死胎、产弱仔、奶水不足、仔猪成活率低、不发情等繁殖性能问题越来越严重,同发达国家相比,母猪年平均贡献商品猪差距越来越大。笔者通过长期观察昌图县几家原种猪场,发现造成母猪繁殖性能低下的主要原因是猪群整体处于亚健康状态,母猪内分泌紊乱。1母猪繁殖性能低下原因1.1饲料卫生指标不达标霉菌毒素和其他工业污染饲料原料进入体内,造成母猪免疫抑制,猪群长期处于亚健康状态。     

夏季危害母猪健康的因素

正养猪赚钱从母猪开始,母猪健康是整个猪场的核心。进入炎热的夏日之后,危害母猪健康的主要因素有霉菌毒素和热应激。在高温高湿的环境下,霉菌毒素对母猪的伤害最大;其次就是热应激对母猪造成极大的影响,导致母猪繁殖性能及抗病性能下降。因此,加强和改善母猪管理,控制霉菌毒素及减少热应激反应,是养猪人在夏季养猪过程中必须重视的一项工作。     

改善三元母猪繁殖性能的策略

改善三元母猪繁殖性能，不仅可以提升母猪生产能力，对增加养殖者经济效益也有重要作用。三元母猪作为当前养殖场繁殖母猪品种之一，不仅对市场环境稳定发展具有重要作用，对母猪繁殖研究发展也很有帮助。笔者从选育、营养等方面介绍提升三元母猪繁殖性能措施，期望能为养殖者提供帮助。     

Genetic analysis of sow longevity and sow lifetime reproductive traits using censored data

Sow longevity is a key component for efficient and profitable pig farming; however, approximately 50% of sows are removed annually from a breeding herd. There is no consensus in the scientific literature regarding a definition for sow longevity; however, it has been suggested that it can be measured using several methods such as stayability and economic indicators such as lifetime piglets produced. Sow longevity can be improved by genetic selection; however, it is rarely included in genetic evaluations. One reason is elongated time intervals required to collect complete lifetime data. The effect of genetic parameter estimation software in handling incomplete data (censoring) and possible early indicator traits were evaluated analysing a 30% censored data set (12 725 pedigreed Landrace × Large White sows that included approximately 30% censored data) with DMU6, THRGIBBS1F90 and GIBBS2CEN. Heritability estimates were low for all the traits evaluated. The results show that the binary stayability traits benefited from being analysed with a threshold model compared to analysing with a linear model. Sires were ranked very similarly regardless if the program handled censoring when all available data were included. Accumulated born alive and stayability were good indicators for lifetime born alive traits. Number of piglets born alive within each parity could be used as an early indicator trait for sow longevity.     

The association between sow and piglet behavior

Sows in modern pig industry are often housed individually in farrowing crates a few days before farrowing until weaning. These farrowing crates limit movements of the sow and therefore also limit them in expressing their behavior. These limitations may lead to distress with the sow and can result in stereotypical behaviors. Because it is possible that the general behavior of the mother sow also influences her piglets, the hypothesis of the present study was that there is an association between the general behavior of sows and the behavior of their piglets. Our results showed that there was indeed an association between the postures and activities of sows and the behavior of their piglets, not only for nursing–suckling behavior. Results also indicated that piglets prefer resting when sows are resting. When sows were standing up, piglets were running around more. Although there were indications that piglets were more at ease when sows were bar biting compared with when they were sham chewing, a specific relationship between sow stereotypical behavior and piglet behavior could not be demonstrated in the present study. Though, it should be taken in mind that relatively low frequencies of stereotypical behaviors were observed. Furthermore, it could be that not only the prevalence of a specific stereotypical behavior is important but also a specific threshold of that specific behavior should be exceeded to induce effects on the suckling piglets. Alternatively piglets could coinduce stereotypical behavior of the mother sow.     

Farrowing hut design and sow genotype (Camborough-15 vs 25% Meishan) effects on outdoor sow and litter productivity

Performance measures were evaluated for 125 outdoor sows and litters of two crossbred genotypes (Camborough-15 and 25% Meishan) and in two farrowing hut designs (American-style and English-style hut). Contemporary breeding groups of second-parity sows were evaluated in an intensive, outdoor research unit. Sow genotype and hut designs were arranged factorially. Seven complete blocks were evaluated over a 21-wk period. No interactions between environment and genotype were identified for sow and litter productivity. Litters farrowing in the English-style huts weaned 1.5 more (P < .05) piglets per sow (because of a lower preweaning mortality, P = .05) than did litters in the American-style huts. The 25% Meishan weaned 1.7 more (P < .01) pigs per sow than Camborough-15, because of a greater number of piglets born alive. The effects of hut style and genotype were additive and 25% Meishan sows in English-style huts weaned an average (+/- SEM) of 11.1 +/- .83 piglets per sow. The English-style arc hut design may improve outdoor pig production and increase competitiveness of the intensive, outdoor system. The 25% Meishan genotype has potential for increased pigs weaned per litter that must be considered in light of other features of this genotype such as body composition.     

Effect of sow vaccination against Mycoplasma hyopneumoniae on sow and piglet colonization and seroconversion, and pig lung lesions at slaughter

The objectives of the present study were to compare Mycoplasma hyopneumoniae (Mh) colonization and serologic status on Mh vaccinated and non-vaccinated sows and to assess the effect of sow vaccination on colonization and serologic status of their piglets at weaning as well as presence of enzootic pneumonia (EP) lung lesions at slaughter. Fifty sows (25 vaccinated and 25 unvaccinated) as well as five of their piglets were included in the study. Blood samples and nasal swabs from sows at 7 weeks pre-farrowing and 1 week post-farrowing and from piglets at 3-4 weeks of age were taken. Nasal swabs and sera were tested by a nested polymerase chain reaction (nPCR) to detect Mh DNA and by an enzyme-linked immunosorbent assay (ELISA) test to detect antibodies to the pathogen, respectively. Finally, at 23 weeks of age, pigs were sent to the slaughter where the extension of EP-compatible gross lesions was assessed. Vaccination with two doses of Mh vaccine resulted in a significantly higher (p<0.05) percentage of seropositive sows than in the non-vaccinated group at 1 week post-farrowing. On the contrary, no statistical significant differences were found in the number of nasal nPCR positive sows among different treatments (p>0.05). At 3-4 weeks of age, a significantly higher percentage (p<0.001) of seropositive piglets came from vaccinated than from non-vaccinated sows. Although the number of Mh infected piglets coming from non-vaccinated sows was higher than the one from vaccinated sows, the difference was not statistically significant (p>0.05). Overall, piglets from vaccinated sows had a significant lower (p<0.05) mean of EP-compatible lung lesions (1.83+/-2.8) than piglets from non-vaccinated sows (3.02+/-3.6). Under the conditions described in this study, sow vaccination did not affect sow or piglet colonization but increased the percentage of seropositive sows and piglets at weaning and reduced significantly the mean EP-compatible lung lesion scoring at slaughter.     

Between-breed variability of stillbirth and its relationship with sow and piglet characteristics

Litter characteristics at birth were recorded in 4 genetic types of sows with differing maternal abilities. Eighty-two litters from F(1) Duroc x Large White sows, 651 litters from Large White sows, 63 litters from Meishan sows, and 173 litters from Laconie sows were considered. Statistical models included random effects of sow, litter, or both; fixed effects of sow genetic type, parity, birth assistance, and piglet sex, as well as gestation length, farrowing duration, piglet birth weight, and litter size as linear covariates. The quadratic components of the last 2 factors were also considered. For statistical analyses, GLM were first considered, assuming a binomial distribution of stillbirth. Hierarchical models were also fitted to the data to take into account correlations among piglets from the same litter. Model selection was performed based on deviance and deviance information criterion. Finally, standard and robust generalized estimating equations (GEE) procedures were applied to quantify the importance of each effect on a piglet's probability of stillbirth. The 5 most important factors involved were, in decreasing order (contribution of each effect to variance reduction): difference between piglet birth weight and the litter mean (2.36%), individual birth weight (2.25%), piglet sex (1.01%), farrowing duration (0.99%), and sow genetic type (0.94%). Probability of stillbirth was greater for lighter piglets, for male piglets, and for piglets from small or very large litters. Probability of stillbirth increased with sow parity number and with farrowing duration. Piglets born from Meishan sows had a lower risk of stillbirth (P < 0.0001) and were little affected by the sources of variation mentioned above compared with the 3 other sow genetic types. Standard and robust GEE approaches gave similar results despite some disequilibrium in the data set structure highlighted with the robust GEE approach.     

芪英汤和子甘汤中药复方促进母猪繁殖性能和断奶仔猪生长性能的临床研究

母猪产死胎、弱胎和断奶仔猪腹泻是兽医临床养猪业亟待解决的问题。为了响应国家在养殖业中执行的“减抗替抗”政策,本文基于中医辩证论治,探讨中草药复方芪英汤、子甘汤分别对母猪繁殖性能和断奶仔猪生长性能的影响。对同期发情的母猪(35头)和同期断奶仔猪(140头)进行中药方剂预混饲料的饲养方式,分别持续饲养至分娩结束、30 d,同时记录母猪分娩数据包括窝均出生仔猪数、窝均重、窝均死胎数、死胎率等,仔猪生长数据包括初重、末重、料肉比和腹泻率,通过酶联免疫吸附方法(ELISA)、荧光定量PCR(RT-PCR)检测母猪血清中IL-6、IL-1β、TNF-α、IgG、IgA、IgM和断奶仔猪血清中IgA的分泌情况以及母猪圆环病毒2型、伪狂犬病病毒、猪繁殖与呼吸综合征病毒及抗体来确定母猪免疫力情况。结果表明,芪英汤可以显著降低妊娠母猪炎性因子IL-6、TNF-α分泌水平,降低低胎次母猪生产新生仔猪死胎率、弱胎率、死亡率,分别下降1.96%、5.83%、8.25%,提高母猪的繁殖性能。子甘汤和芪英汤联用能够显著提高仔猪断奶后期IgA水平,降低腹泻率和料肉比, 提高生长性能,降低断奶仔猪血液中白细胞水平,红细胞恢复到正常水平。综上,中药复方芪英汤和子甘汤有助于提高母猪繁殖性能和恢复断奶仔猪生长性能。     

Impact of dominance effects on sow longevity

The purpose of the current study was to estimate variance components, especially dominance genetic variation, for overall leg action, length of productive life and sow stayability until third and fifth parity in the Finnish pig populations. The variance components were estimated in two purebred [Landrace (LR), n = 23 602 and Large White (LW), n =22 984] and crossbred (LR × LW, n = 17 440) data sets. Five different analyses were carried out for all the traits to compare the effect of sows’ inbreeding, common litter environment and parental dominance in the statistical model when determining the genetic correlations of the traits for the two purebred and crossbred populations. Estimated heritabilities for the traits ranged from 0.04 to 0.06. The estimates for the proportion of dominance variance of phenotypic variance (d²) varied between 0.01 and 0.17, and was highest in the crossbred dataset. The genetic correlations of the same traits in purebred and crossbred were all high (>0.75). Based on current results, the effect of dominance should be accounted for in the breeding value estimation of sow longevity, especially when data from crossbred animals are included in the analyses. Because dominance genetic variation for sow longevity exists that variation should be utilized through planned matings in producing sows for commercial production.     

Improving sow efficiency by management to enhance opportunity for nutritional intake by neonatal piglets

Starvation, primarily during the first week postpartum, is the direct or indirect cause of at least one-half of preweaning mortalities in healthy herds. Causes of starvation originate from characteristics of the dam, of the litter and of individual piglets. A major cause of starvation is congenital weakness associated with birth weights less than 1000 g. Increasing energy during late gestation shows inconsistent effects on birth weight; some dietary component energy sources appear to improve stamina of newborn and(or) energy content of sow's milk with favorable effects on survival. Total or partial supplemental nutrient intake supplied by caretakers, automated feeding devices or transfer of piglets to foster dams are the primary means of providing enhanced nutrient intake opportunity. Nutrient intake from non-dam sources ranges from temporary tube-feeding, administered by caretakers to excessively small or weak pigs, to self-feeding by pigs from simple or sophisticated dispensers of sow milk substitutes. Transfer of piglets to foster dams as a nutrient intake source is most successful when characteristics such as size of dam, size of teats, stage of lactation and temperament are in harmony with characteristics affecting pigs' needs. If other dams are not available, sows 2 to 3 wk into lactation can serve as foster dams for large and strong newborn piglets after resident litters are removed. Planning for availability of appropriate foster dams, based on prior or projected prolificacy and other sow and litter traits, should be done at time of assembling each mating group. Research results show that, on a weight-to-weight basis, pigs requiring artificial or foster dam rearing perform similarly to other pigs and thus justify management to secure their survival.     

Impacts of a freedom farrowing pen design on sow behaviours and performance

The limited space in farrowing crate imposes many challenges, such as prolonged farrowing duration and high piglet stillbirth rate. Although the features of farrowing pens compensate for the drawbacks of farrowing crates, they are associated with high piglet crushing mortality caused by the greater space afforded to sows and their rolling-over behaviour. Therefore, a freedom farrowing pen was designed to overcome the drawbacks of both farrowing crates and farrowing pens. The main features of the freedom farrowing pen are its left anti-crushing bar and detachable right anti-crushing bar on the sides of the sow lying area. It also has a 10 cm-high anti-crushing bar in the non-lying area. Eighteen healthy, multiparous Yorkshire sows (3-7 parity) were averaged and randomly assigned to farrowing crates, farrowing pens, and freedom farrowing pens to compare the effects of the farrowing systems on sow behaviour and performance. Results showed that the farrowing duration and the mean piglet birth intervals were longer for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P<0.05), but there was no difference between the sows in farrowing pens and those in freedom farrowing pens (P>0.05). The piglet stillbirth rate was higher for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P<0.001). Crushing mortality was higher among piglets in farrowing pens (P<0.001), but there was no difference between piglets in freedom farrowing pens and those in farrowing crates (P>0.05). The freedom farrowing pen and the farrowing pen allowed sows to turn around and move freely, but because of the different structures of their anti-crushing bars, the increase in sow movement did not cause higher piglet crushing mortality (P>0.05). Sows in freedom farrowing pens were found to be more protective of their piglets.     

Effects of sow-crate design on sow and piglet behavior

The effects of sow-crate design on certain behaviors of sows and piglets at farrowing and again approximately 3 wk later were evaluated with a 2 x 2 x 4 factorial arrangement of crate width (narrow [N = 55 cm] or wide [W = 64] between lowest horizontal pipes), length (short [S = 183 cm] or long [L = 198] from rump stop to front gate) and side type (lower side of sow crate "fingered" [F], "bowed" bottom bar 20 cm above the floor [B], or straight bottom bar 20 cm [S20] or 25 cm above the floor [S25]). Farrowing-crate design influenced both sow and piglet behaviors both during and immediately after parturition and during nursing-suckling bouts approximately 3 wk later. Activities of 51 sows and their piglets were videorecorded during and immediately following parturition. Sow-crate design affected neither the interval between births of successive piglets in a litter nor the frequency of standing by the sow during parturition. Latency from birth to first mammary contact (LMC) was greater with S25-sided and S sow crates, and especially with S, W crates. A significant interaction occurred between sow-crate side type and dimensions; LMC was longer when S25 sides were combined with S or W crates. Data on suckling behavior were collected from 113 litters over three successive sucklings approximately 3 wk after farrowing. Sow-crate design had no effect either on the consistency with which a piglet suckled a particular teat or teat pair or on the frequency of multiple-teat use. Piglets maintained fewer functional teats with S, S20 crates. The distribution of functional teats between rows was less symmetric with S crates. Piglets nursed with their bodies over a side bar more frequently with B- and S20-sided crates. The sow permitted her piglets to suckle while she was in a vertical stance more frequently with S and N crates, and especially with S, N crates. Sow-crate design affected important behaviors of sows and piglets both during and immediately after parturition as well as during nursing-suckling bouts about 3 wk later.