夏季热应激对种公猪的影响及预防措施

正随着养猪业规模化、集约化发展,热应激已严重影响种公猪的生产性能。种公猪最适宜的环境温度为13~19℃,种公猪超过25℃就会产生热应激,每年7~8月份我国大部分地区的环境温度持续在30℃以上,会导致种公猪性欲减退,精液品质下降,严重影响养猪业的经济效益。为了避免热应激对种公猪的不良影响,应采取防暑降温、营养调整和加强饲养管理等措施加以预防。1热应激对种公猪的影响(1)高温可引起种公猪性欲降低。在高温环境下,     

公猪的饲养管理

<正>1公猪的生理特性和管理要点(1)使用年龄是决定公猪生产性能的重要因素。睾丸重量和精液容量决定了公猪的繁殖力,公猪的睾丸会一直生长到12月龄。而精液产量则到半年后才能达到最高水平。因此一岁龄前的种猪不应作为成年公猪使用,而应精细饲养。(2)适宜的环境条件。适合公猪生产的最佳温度为18～20℃,30℃以上就会使公猪产生热应激,进而影响精液品质,一般4～6周后表现明显,精子量明显下降,成活率低,活力差,母猪返情率高和产仔数少,想恢复原有水平需要的时间很长。光照时间过     

规模化猪场夏季饲养管理及保健要点

夏季气温高,给猪场生产带来不少问题,对规模化猪场的影响更为突出,如热应激、采食量下降、增重减慢、繁殖障碍等,本文拟对高温季节猪场的饲养管理及保健问题进行初步探讨。1猪群热应激的表现妊娠母猪的最适温度为22℃～25℃,哺乳母猪为15℃～18℃,公猪为15℃～18℃,哺乳仔猪为28℃～32℃,保育猪为24℃～28℃,肉猪为18℃～21℃。当环境温度高于32℃时,猪群则出现热应激。1.1公猪性欲降低、精液品质下降。一般认为公猪睾丸造精机能产生障碍的极限温度为30℃,相对湿度为85%,遭受高温的公猪精液品质降低,并且会导致其受应激过后4～6周繁殖力较低…     

夏季高温对种猪的影响及应对措施

1高温对种猪的影响1.1高温对种公猪繁殖力的影响当环境温度高于33℃,种公猪深部体温超过40℃时,则会导致睾丸温度升高。精液质量随之降低,精液中精子数减少,活力降低,甚至死精。夏季高温应激后7～14天开始,公猪精液品质下降,一般高温后6～8周精液品质才能恢复正常。高温还能使公猪的性欲降低。     

夏季热应激对种猪繁殖力的影响及控制措施

随着全球气候温室效应的不断加剧及高度集约化动物生产的发展,热应激对种猪繁殖力的影响越来越明显,就种猪而主言,其适宜的环境温度为种公猪13-19℃,空怀及孕前期母猪13-19℃,孕后期母猪16-20℃,哺乳期母猪18-22℃。种公猪超过25℃便会产生生热应激,种母猪超过27℃便会产生热应激。     

高温季节饲养种公猪的几项应对措施

饲养种公猪的关键就是提高其精液品质。种公猪精液品质受季节的影响较大,特别是夏季高温季节,由于猪的汗腺不发达,耐热性能差,易产生热应激反应,当环境温度超过37℃且持续时间超过1星期以上时,种公猪的性欲明显减退,精液品质下降,采精量少,精子的体外保存时间明显缩短。公猪长时间处于热应激生活环境下,还可导致精子发育不良和精子受损,睾丸生精机能发生障碍,进而造成种猪种用年限缩短和种用价值降低,严重时还可造成睾丸生精机能永久性丧失。同时高温也是诱发公猪发生睾丸炎的重要因素。养好种公猪,提高繁殖力,对以自繁自养为主的猪场来说,显得尤为重要。     

热应激对种猪繁殖力的影响及对策

外界环境因素,包括空气温度、空气湿度、气流和太阳辐射等对种猪繁殖力有一定影响,其中温度是影响种猪繁殖力最重要的环境因素。超过25℃种公猪便会产生热应激,超过27℃种母猪便会产生热应激。种猪遭受热应激时即会做出适应性反应(增加散热和减少产热),进而引起采食量及饲料利用率降低,机体代谢紊乱,内分泌异常,性机能紊乱,繁殖力降低。本文就热应激对种猪繁殖力的影响以及减轻热应激对种猪繁殖力影响的对策作了综述。     

种公猪的几项管理措施

种公猪在养猪生产中有着重要的影响,如果种公猪生产性能不好,直接影响到母猪的产仔性能,从而影响养猪的经济效益,而且这种影响是深远和巨大的。因此,养猪生产中必须重视种公猪的饲养管理。通过加强饲养,完善管理,达到提高种公猪生产性能与繁殖力，延长使用寿命，提高养猪经济效益的目的。     

炎夏减缓奶牛热应激的几项措施

炎夏热应激是导致奶牛夏季产奶量和繁殖力下降的最重要的原因之一。热应激由此造成的损失也是十分明显的．如产奶量下降，繁殖力下降。为缓解和减少热应激对奶牛的危害，最主要的应从环境和营养两方面加大饲养管理力度。1热应激的症状,奶牛的理想温度范围为4℃-18℃。温度一旦超过27℃，奶牛的采食量就会下降。开始对奶牛产生不利影响。     

保持公猪精液产量的饲喂策略

人工授精中心的公猪在冬季射出的精子数减少,这可能是较低的环境温度及其影响公猪能量代谢的缘故。在温度适中(大于20℃)条件下每天沉积100克蛋白质和40克脂肪的公猪,在冬季会每天失重155克脂肪。我们发现饲喂额外的饲料能阻止公猪失重。为了查明饲养水平对种公猪繁殖力的影响,我们用42头13月龄,222千克活重、膘厚15.2毫米的约克夏公猪进行了一项饲养试验。     

公猪营养与繁殖

公猪的重要性越来越得到广泛的关注。尽管种公猪在猪群中占据比例不高,但是种公猪的繁殖性能可以直接影响母猪的妊娠率和产仔数,进而影响猪场的整体经济效益。公猪的精液品质是其繁殖力的基础,同时也是发挥公猪遗传性能的重要保障。文章综合了近年来国内外研究公猪营养对精液品质及繁殖力的调控,从膳食纤维、蛋白质及氨基酸、多不饱和脂肪酸、微量元素及维生素、植物提取物、有益菌群等方面分析了它们如何改善公猪精液品质,但是有关研究还很不完善、不系统。因此,需要根据种公猪不同品种、不同生长阶段、不同环境条件下对各类营养物质的需求来制定合理、合适的种公猪饲料配方,以期发挥种公猪的最大潜力和价值。     

Multivariate Analyses for Determining the Association of Field Porcine Fertility With Sperm Motion Traits Analysed by Computer‐Assisted Semen Analysis and With Sperm Morphology

This study investigates the association of semen traits with boar fertility. The fertility outcome (farrowing rate – FR and total piglets born – TB) of 14 boars was obtained from a field trial conducted during 10 week of breeding period on a commercial farm using multiparous sows (n = 948) through single‐sire mating with 2 × 10⁹ motile sperm cells per artificial insemination (AI) dose. Sperm motion parameters, evaluated with computer‐assisted semen analysis system in raw and stored semen at 17°C for 240 h, in addition to morphological sperm defects, measured on the collection day, were included in the analysis to determine which semen traits were important to discriminate the fertility potential of ejaculates from these boars. The data underwent multivariate cluster, canonical and discriminant analyses. Four clusters of boars were formed based on fertility outcome. One boar, with the lowest FR and TB values (89.7% and 11.98), and two boars, with the highest FR and TB values (97.8% and 14.16), were placed in different clusters. The other boars were separated in two distinct clusters (four and seven boars), including boars with intermediate TB (12.64 and 13.22) but divergent values for FR (95.9% vs 91.8%). Semen traits with higher discriminatory power included total motility, progressive motility, amplitude of lateral head displacement and cytoplasmatic droplets. Through multivariate discriminant analysis, more than 80% of the 140 ejaculates were correctly classified into their own group, showing that this analysis may be an efficient statistical tool to improve the discrimination of potential fertility of boars. Nevertheless, the validation of the relationship between fertility and semen traits using this statistical approach needs to be performed on a larger number of farms and with a greater number of boars.     

骨桥蛋白在长白公猪生殖细胞中的表达及其与繁殖性能的相关性

本试验旨在研究骨桥蛋白（osteopontin,OPN）在长白公猪生殖细胞中的表达和定位,并探究其与公猪繁殖性能的相关性。试验采集了长白公猪精液和不同阶段（3日龄、3月龄、6月龄和12月龄）的睾丸组织,通过蛋白印迹的方法检测OPN蛋白在精液和不同月龄睾丸中的表达,通过免疫组化的方法对OPN蛋白在公猪睾丸细胞中进行定位;同时,根据配种胎次≥ 20胎,3次配种公猪为同一头的标准,筛选并采集17头长白种公猪精液,统计相对应的1 388头母猪的生产成绩,计算得到公猪繁殖性能指标（包括窝产总仔数、窝产活仔数、分娩率和繁殖力）。低温离心精液分离得到精子和精浆,丙酮法提取精浆蛋白,Lysis buffer方法提取精子蛋白,最后运用BCA和ELISA的方法检测精子和精浆中OPN蛋白的含量,分析OPN蛋白与公猪繁殖性能的相关性。蛋白印迹结果显示,OPN在精子、精浆和各月龄阶段的长白公猪睾丸中均以两种形式表达（67.4和33.7 ku）,且67.4 ku的形式在3月龄公猪睾丸中表达量最高;免疫组化的结果显示,OPN在长白公猪的初级精母细胞、次级精母细胞和精子细胞中表达,在精母细胞、支持细胞和间质细胞中无表达;BCA和ELISA结果显示,精子中的OPN蛋白含量是精浆中的7倍（P<0.05）,精液中的OPN蛋白与公猪窝产活仔数显著正相关（P<0.05）。本试验结果表明,OPN在各阶段的长白公猪睾丸中都有表达,且在精子和精浆中也有表达,这可能与公猪的繁殖性能有关,从而为后期OPN蛋白在公猪受精力的研究奠定基础。     

The relationship of porcine sperm zona-binding ability to fertility

Several laboratory assays have been designed to assess the fertility potential of a semen sample before insemination, but none have been consistent and accurate predictors of fertility. To determine whether zona-binding ability may be a useful fertility predictor, we validated and used an in vitro competitive assay to measure the ability of porcine sperm to bind to the zona pellucida. The zona-binding ability of sperm from 11 boars that exhibited a broad range in average litter size and farrowing rate was determined. Sperm from each boar were compared directly with sperm from eight other boars in a systematic, pairwise fashion. Sperm from two semen samples were labeled with fluorophores at concentrations that did not affect motility or zona-binding ability. An equal number of labeled sperm from each boar was coincubated with homologous oocytes. Least squares means from analysis of variance were used to rank boars based on zona-binding ability. The competitive assay was effective in establishing a ranking of the boars (R2 = 0.62). Furthermore, there was a correlation between zona-binding ability and fertility when estimated by average litter size (r = 0.64, P < 0.05) but not when estimated by farrowing rate (r = -0.28). The explanation for this difference was that litter size and farrowing rate were poorly correlated (r = 0.14). In conclusion, a competitive zona-binding assay distinguished boars that sired either small or large litters. Competitive zona-binding ability may be useful for identifying boars with reduced fertility that produce smaller litters following insemination.     

Boar culling in swine breeding herds in Minnesota

This investigation was conducted to study boar culling patterns in swine breeding herds. Data were obtained from 84 swine breeding herds and included 440 boars that were culled. Each producer was involved for 12 consecutive months, and recorded every boar that was removed from the herd, the date, and the reason for culling. The annual culling rate for the 84 farms averaged 59.4% ± 6.4 (SEM). The correlation coefficient between boar and sow culling was 0.52 (p <0.0001). Removal was the result of being overweight (47%), reproductive problems (18%), leg problems (12%), death (7%), and other diseases (4%). From the annual culling rate, the average breeding life of boars was estimated at 20 months. From this study, we concluded that the annual culling rate for boars in commercial herds was high and related to several different factors.     

湿热环境对后备公猪采食行为和饲料效率的影响

为分析中国南方高温高湿环境对扬翔华系杜洛克后备公猪在生长育肥期采食量、采食时间等采食行为和饲料效率的影响,本研究以扬翔华系杜洛克后备公猪在FIRE测定站的998 195条采食记录为基础,使用温湿度自动监测设备实时监测圈舍温度和湿度。采用R 3.5.1软件统计猪群昼夜采食节律,运用线性混合模型分析不同温湿度水平采食行为和饲料效率的差异,并尝试建立扬翔华系杜洛克生长公猪实际采食量预测模型。结果表明:扬翔华系杜洛克生长猪的采食行为呈昼夜节律变化,受日温度变化影响;当环境温度在20～24℃,温湿指数(THI)在66～71时,生长猪的饲料转化率(FCR)和剩余采食量(RFI)均较低;当环境温度超过25℃,THI超过74时,FCR最高可提高13.98%,RFI最高可提高182.92%。综上可知,在华南地区湿热环境下,当环境温度控制在18～22℃、THI在65～70时,扬翔华系杜洛克生长公猪的采食量较高,FCR和RFI较低,饲料效率较高。THI可作为监测生长公猪热应激的候选指标。     

北京迪卡猪核心群育种方案优化研究——群体规模及选择强度

应用确定性模型考察群体规模对北京迪卡猪核心群公猪系育种成本、育种产出、育种效益及近交系数的影响。猪规模为６０、８０、１００、１２０四个水平，公猪头猪为６、８、１０、１２四个水平。种畜的选择是基于多性状综合选择指数进行，应用基因流动法计算育种产出。结果表明，增加母猪规模，有利于提高公猪选择强度，从而加大育种产出，同时单位母猪育种成本下降，促进了育种效益的改善；公猪头数越少，公猪选择强度越大，育种进展     

Biological markers of boar fertility

The semen evaluation techniques used in most commercial artificial insemination centers, which includes sperm motility and morphology measurements, provides a very conservative estimate of the relative fertility of individual boars. As well, differences in relative boar fertility are masked by the widespread use of pooled semen for commercial artificial insemination (AI) in many countries. Furthermore, the relatively high sperm numbers used in commercial AI practice usually compensate for reduced fertility, as can be seen in some boars when lower numbers of sperm are used for AI. The increased efficiency of pork production should involve enhanced use of boars with strong reproductive efficiency and the highest genetic merit for important production traits. Given that the current measures of semen quality are not always indicative of fertility and reproductive performance in boars, accurate and predictive genetic and protein markers are still needed. Recently, significant efforts have been made to identify reliable markers that allow for the identification and exclusion of sires with reduced reproductive efficiency. This paper reviews the current status of proteomic and genomic markers of fertility in boars in relation to other livestock species.     

GPx6在大白猪附睾细胞中的表达及其与繁殖性能的相关性

本试验旨在研究谷胱甘肽过氧化物酶6（glutathione peroxidase 6,GPx6）在大白公猪附睾细胞中的表达和定位,并探究其与公猪繁殖性能的相关性。选取15月龄的公猪和母猪各3头,取睾丸、附睾、前列腺、尿道球腺、精囊腺、卵巢和输卵管,提取蛋白,通过蛋白免疫印迹和免疫组化（IHC）检测组织和细胞中GPx6蛋白的表达和定位;根据评定大白公猪受精能力的数学模型,按照公猪配种胎次≥20胎、3次配种公猪为同一头的标准,筛选并采集符合要求的20头公猪精液,同时,统计相对应的1 279头母猪的生产成绩,计算得到公猪繁殖性能指标（包括窝产总仔数、窝产活仔数、分娩率和繁殖力）。提取精子蛋白和精清蛋白,通过BCA和ELISA检测精子和精清中GPx6蛋白的含量。使用SPSS软件的独立样本t检验及单因素方差分析（one-way ANOVA）,进行差异显著性分析,用双变量Pearson进行相关性分析,P<0.05表示差异或相关显著。结果表明,GPx6蛋白在附睾中高表达,IHC结果显示,GPx6蛋白在附睾的顶细胞、基底细胞、晕细胞、主细胞和精子中表达,在肌样细胞中不表达;精清蛋白中GPx6的含量是精子蛋白的7倍,精液中GPx6蛋白的含量与窝产活仔数、窝产总仔数呈负相关关系。结果提示,GPx6在附睾的顶细胞、基底细胞、晕细胞、主细胞和精子中表达,且其在精液中的含量会影响公猪的繁殖性能,这为GPx6对公猪受精能力影响的研究奠定了理论和试验基础。     

全模拟自然生态条件下杂交野猪繁育与肥育性能测定

为了研究杂交野猪的生长性能、繁育水平与养殖环境、运动量、饲料配制的关系,根据野猪生活习性,对杂交野猪放养区内生活环境进行模拟(包括野猪巢穴、生态环境、植被),使杂交野猪能够有更多的运动范围和获取野外食物的机会。结果表明,放养模式下的杂交野猪产仔率(P<0.05)、仔猪存活率(P<0.01)均高于圈养模式杂交野猪,但增重速度显著(P<0.05)低于圈养模式下饲养杂交野猪。由试验结果可以得出,圈养模式下杂交育肥野猪增重速度显著高于放养杂交野猪,饲养管理难度较低,适合集约化大规模饲养。