新丹系瘦肉型公猪生长发育规律和生长曲线拟合分析

为了解新丹系瘦肉型公猪的生长发育规律,研究采用Logistic和Gompertz两种生长曲线模型(分别简称L模型和G模型)对85～180日龄杜洛克公猪、长白公猪和大白公猪的体重进行了拟合与分析。结果表明:两种模型均能较好地拟合3个品种公猪的生长曲线,杜洛克公猪以G模型拟合效果较好,长白公猪和大白公猪以L模型拟合效果更佳;3个品种公猪最佳模型的拟合度(R~2)分别为1.000,0.999,0.999,模型方程分别为W_t=227.43e~(-6.00e-0.01t)/sup,W_t=149.14/(1+48.59e~(-0.03t)),W_t=124.63/(1+48.32e~(-0.03t))。     

48团良种猪杂交配套体系试验研究

用杜洛克、长白、大白和皮特兰优良瘦肉型猪进行二元杂交,用杜洛克、长白、大白等优良瘦肉型猪与杜洛克进行三元杂交,用杜洛克、长白、大白等优良瘦肉型母猪与皮特兰公猪进行三元杂交,比较杂交一代的生产性能。试验结果表明,大长和长大生长发育最快;杜×大长皮断奶窝重与成活数最好;杜     

不同品种公猪精液品质调查

为了研究品种不同的种公猪的精液品质之间存在的差异,本试验通过对长白、大白、杜洛克等3个品种的成年种公猪的精液品质进行统计学方法分析和比较。结果显示:长白公猪的精子活率最好(75.03%),然后依次是大白(71.62%)、杜洛克(70.36%),长白与大白及杜洛克之间差异显著(P<0.05),但大白与杜洛克之间差异不显著(P>0.05);长白种公猪的精液量(337.60mL)与大白(380.00mL)之间差异不显著(P>0.05),但均与杜洛克(251.74mL)之间差异显著(P<0.05)。三个品种精子活率由高到低依次为长白、大白、杜洛克;平均精液量大小依次为大白、长白、杜洛克,综合评价,长白猪的精液品质最好。     

品种和采精季节对公猪精液品质和稳定性的影响

为探究品种和采精季节对公猪精液品质与稳定性的影响,本实验采用混合线性模型对来自广西扬翔某公猪站1203头公猪(607头杜洛克,265头大白,331头长白)的68234份精液数据(杜洛克32491份,大白14796份,长白20947份)进行统计学分析,并对精液性状进行相关性分析.结果显示:长白在精液体积方面(219.96...     

不同品种的种公猪精液品质差异的研究

为了研究品种不同的种公猪的精液品质之间存在的差异。本试验通过对长白、大白、杜洛克和斯格配套系等4个品种的成年种公猪的精液品质进行统计学方法分析和比较。结果表明:1斯格配套系种公猪的鲜精活率最好(0.89±0.12),然后依次是长白(0.88±0.13)、杜洛克(0.86±0.11)、大白(0.85±0.16)。2杜洛克和斯格种公猪的精子有效存活时间(分别为8.5 d和8 d)比长白、大白种公猪的精子有效存活时间长(分别为6.5 d和6 d)。3大白种公猪的精液密度最大(6.62亿/m L),杜洛克种公猪的精液密度次之(6.51亿/m L),然后是斯格(4.51亿/m L)、长白(4.41亿/m L)。4长白种公猪的精液量(349 m L)与大白(225 m L)、杜洛克(179 m L)、斯格(265 m L)等种公猪的精液量差异极显著(P0.01);斯格种公猪精液量与杜洛克种公猪的精液量差异极显著(P0.01);大白种公猪的精液量与杜洛克、斯格种公猪的精液量差异不显著(P0.05)。5长白种公猪的总精子数最大(2 080.1亿/次),大白次之(2 060.3亿/次),其次是杜洛克(2 010.7亿/次)和斯格(2 002.1亿/次),但四个品种的种公猪的总精子数差异不显著(P0.05)。4个品种的种公猪的精子活率由高到低依次为斯格、长白、杜洛克、大白;大白种公猪的精液密度最大;杜洛克和斯格种公猪比较适合长期保存,长白、大白种公猪仅适合短期保存;4个品种的种公猪的平均精液量大小依次为长白斯格大白杜洛克;4个品种的种公猪的总精子数的大小依次为长白大白杜洛克斯格。     

不同品种猪精液品质的季节性变化规律研究

在不同季节采集56头大白、长白、杜洛克公猪的精液,对精液品质进行了评定和分析。结果表明:在一年内,杜洛克和大白公猪的精液品质均以秋季最好,春季次之,夏季最差,而长白公猪的精液品质以春季最好、夏季最差;精液量有显著(P<0.05)的品种间差异,长白猪、大白猪、杜洛克猪依次降低;精子活率表现为杜洛克猪、大白猪、长白猪依次降低但差异不显著(P>0.05);精子畸形率以长白猪为最高,而在各品种间差异也不显著(P>0.05)。经综合评定,在受试的3个品种公猪中,杜洛克猪的精液品质较好,而且在夏季也优于其他2个猪种。     

南通地区不同品种公猪夏季精液品质变化

通过对江苏省南通如东家畜改良站内不同品种公猪夏季精液品质的检测,探讨了该地区夏季高温对不同品种公猪的精液品质的影响。选取大白、长白、杜洛克和梅山4个品种公猪,采集精液并分析各品种在5、6、7、8和9月的精液体积、密度和精子总数变化。结果表明:与5月相比,长白和梅山公猪7月精液体积显著减少(P<0.05),长白和大白公猪9月精液密度显著减少(P<0.05),并且长白、大白和杜洛克9月精子总数显著降低(P<0.05);而梅山公猪精子总数未出现显著变化。可见,南通地区夏季高温影响公猪精液品质,并且相较外来猪种,梅山猪耐热性能较好。     

杜洛克、长白、大白原种猪及其二元、三元猪肌内脂肪测定的相关研究

本研究使用索氏抽提法,参考国标GB/T 9695.1—2008/ISO 1444:1996《肉与肉制品—游离脂肪含量的测定》,使用乙醚抽提单块肌肉待测样中脂肪。研究结果表明,大白猪和二元猪肌内脂肪含量均与杜洛克母猪存在显著差异;而长白猪、杜洛克母猪两个品种间和三元猪之间肌内脂肪含量差异不显著;长白猪和大白猪两个品种与二元猪和三元猪间平均肌内脂肪含量均差异不显著。长白猪、大白猪和二元猪公母间,公猪的平均肌内脂肪含量均高于母猪。其中长大去势公猪与长大母猪的平均肌内脂肪含量存在显著差异。而长白公猪和长白母猪、大白公猪和大白母猪、大长去势公猪和大长母猪,平均肌内脂肪含量均差异不显著。     

不同品种公猪睾丸体积、精清中睾酮水平及其与精液品质关系的初步研究

本研究的目的是比较美系长白、大白和杜洛克种公猪睾丸体积、精清中睾酮含量与精液品质的关系。研究采集了44头杜洛克、31头长白和22头大白种公猪的精液并测定其精液品质,测量其睾丸的长度、宽度和厚度。结果表明,种公猪睾丸体积从大到小依次为大白、长白、杜洛克;长白在精子密度、活力和畸形率方面是较好的,杜洛克精液品质是3个品种中较差的;睾酮含量与精液品质呈弱相关,睾酮含量与睾丸体积不相关,精液品质与睾丸体积不相关。     

猪群亚健康的中医学探讨

自19世纪初欧洲对瘦肉型猪进行品种选育以来,大白、长白、杜洛克等瘦肉型品种猪的抗病力、生长速度、生殖性能等已经步入了一个较为健康的发展水平。而自从我国引入瘦肉型品种猪以后,"洋猪中用"却陷入了"引种—退化—再引种—再退化"的恶性循环的怪圈。疾病暴发、生长     

品种、季节、胎次、采精月龄及采精间隔对猪精液品质的影响

【目的】探究品种、公猪出生胎次、公猪同窝仔猪数、公猪乳头数、采精季节、采精月龄和采精间隔对猪精液品质的影响,以及不同品种对精液质量稳定性的影响。【方法】选取909头杜洛克、长白、大白种公猪为试验群体,收集2021年4月至2022年4月27 408条精液测定记录,采用混合线性分析模型和方差分析探究品种、公猪出生胎次、公猪同窝仔猪数、公猪乳头数、采精季节、采精月龄和采精间隔对精液体积、精液密度、精子活力、直线前进运动精子比例、精子畸形率、总精子数及各精液性状稳定性的影响。【结果】从不同品种对精液品质的影响来看,长白猪精液体积和总精子数均显著高于大白猪、杜洛克猪(P＜0.05),杜洛克猪精液密度显著高于大白猪和长白猪(P＜0.05),杜洛克猪、大白猪精子活力均显著高于长白猪(P＜0.05),大白猪直线前进运动精子比例显著高于长白猪和杜洛克猪(P＜0.05),长白猪和大白猪精子畸形率均显著低于杜洛克猪(P＜0.05);从不同公猪出生胎次对精液品质的影响来看,1~3胎出生的公猪具有较高的精液品质;从不同采精季节对精液品质的影响来看,精液密度、精子活力和总精子数秋、冬季显著高于春、夏季(P＜0.05);从不同采精月龄对精液品质的影响来看,16~25月龄公猪具有较高的精液品质;从不同采精间隔对精液品质的影响来看,4~5 d为最佳采精间隔,采精间隔过长会导致精子畸形率上升;从不同公猪总乳头数来看,乳头数13~16个时,各精液性状品质都处于中等水平,有利于公猪生产应用。3个品种各精液性状间稳定性趋势不一,杜洛克猪和大白猪精液体积和精子活力的稳定性均显著高于长白猪(P＜0.05),杜洛克猪精液密度、精子畸形率和总精子数的稳定性均显著高于大白猪和长白猪(P＜0.05),大白猪直线前进运动精子比例的稳定性显著高于长白猪和杜洛克猪(P＜0.05)。各品种中,长白猪稳定性较差;各精液性状中,精子活力稳定性最好。【结论】品种、公猪出生胎次、采精季节、采精月龄和采精间隔均会影响公猪精液品质,可根据不同品种公猪制定更完善的选择方案,提高精液质量,加速公猪遗传改良。     

晋汾白猪生长发育性状的选育研究

晋汾白猪是以马身猪、太湖猪、长白猪和大白猪为育种素材,通过复杂杂交育种和标记辅助选择而育成的一个瘦肉型猪新品种。试验对6个世代后备猪生长发育性状的选育结果进行分析,结果发现,后备公猪6世代与0世代相比,初生重提高了0.13 kg,断奶重提高了0.56 kg,70日龄体重提高了1.69 kg,180日龄体重提高了12.46 kg,70~180日龄平均日增重提高了107.00 g,差异均显著(P<0.05);后备母猪180日龄体重6世代比0世代显著提高了10.84 kg(P<0.05)。后备公猪和母猪4、5世代的初生重、断奶重、180日龄体重和70~180日龄日增重均显著高于0世代(P<0.05)。选育结果表明,晋汾白猪的生长发育性状取得了较大的遗传进展。     

不同配种模式对二元母猪繁殖性能的影响

为探讨不同配种方式对二元母猪产仔数的影响,以杜洛克猪、长白猪、大白猪、皮特兰猪四个品种公猪精液采用人工授精的方法对11654头长大二元母猪配种,对所产11654窝总产仔数、窝产活仔数、窝损失等进行统计和分析,分析不同配种模式对二元母猪繁殖性能的影响。结果表明,配种次数、不同品种公猪组合配种对二元母猪总产仔数、产活仔数以及窝损失均无显著影响（P〉0.05）,但杜洛克公猪所配二元母猪的总产仔数和窝产仔数均高于大白和长白猪（P〈0.05）;采用长×杜×大组合配种的二元母猪总产仔数和窝产活仔数均高于其它三种组合。试验结果表明,在生产中,可在长白、大白、杜洛克猪中任选两个品种,通过二次配种的方式提高母猪的产仔数。     

不同品种、月份、月龄及采精间隔对猪精液品质的影响

为研究不同品种、采精月份、采精月龄和采精间隔等因素对加系公猪精液品质的影响,以及品种、初次采精周龄对精液质量稳定性的影响,本研究以江西某种公猪站79头加系大白猪、长白猪、杜洛克猪种公猪为试验群体,收集2018年12月至2020年12月3 921条精液采集与精液质量数据,通过混合线性模型与方差分析探究各因素对精液量、精液密度、精子活力、总精子数及其稳定性的影响。结果显示,从不同品种对精液质量的影响来看,长白猪精液量和总精子数均高于大白猪、杜洛克猪,但杜洛克猪精液密度高于长白猪、大白猪,杜洛克猪精子活力最低;从不同月份来看,1~3月采精精液密度最高,4~6月采精精子活力最高,10~12月采精精液量和总精子数最高,精液量呈现秋冬多、春夏少的季节变化规律。公猪不同月龄采精,精液质量指标也存在差异,月龄越小精液量越低,但精液密度偏高,精子活力相对较好,在19~24月龄黄金期总精子数最高。不同采精间隔对精液质量有较大影响,采精间隔越长,精液量、精液密度、精子活力和总精子数相对较好,采精间隔为5 d时综合性能最佳,但过长的采精间隔导致精子活力降低。品种影响总精子数稳定性,长白猪、大白猪总精子数稳定性显著优于杜洛克猪（P<0.05）。本研究结果表明,品种、采精月份、采精月龄和采精间隔均会影响公猪精液质量,关注这些因素有助于公猪站制定更完善的生产计划,提高公猪利用率。     

Heritability of susceptibility to scrotal herniation in swine

Data on 5,711 Duroc-sired, 2,227 Landrace-sired, and 2,494 Yorkshire-sired male pigs born over a 9-year period were used to evaluate the genetic influence on scrotal herniation. Differences in frequency of this defect among boar breeds (Duroc, Landrace, and Yorkshire) were significant (P less than 0.01). Differences among sires within the Duroc and Landrace boar groups were significant (P less than 0.001 and P less than 0.05, respectively), but differences within the Yorkshire group were not significant. Frequency of scrotal hernia among male full siblings of affected males was consistently higher than the overall frequency of the defect among progeny in each of their respective breed of boar groups. Percentage of affected pigs among male full siblings of affected males for Duroc, Landrace, and Yorkshire groups, respectively, was 3.0, 3.0, and 2.7 times greater than the overall percentage affected in their respective breed groups. Heritability of susceptibility to scrotal hernia development was estimated to be 0.29 +/- 0.17, 0.34 +/- 0.23, and 0.34 +/- 0.19 in Duroc, Landrace, and Yorkshire-sired pig groups, respectively.     

Detection and duration of porcine reproductive and respiratory syndrome virus in semen, serum, peripheral blood mononuclear cells, and tissues from Yorkshire, Hampshire, and Landrace boars.

Because transmission of porcine reproductive and respiratory syndrome virus (PRRSV) can occur through boar semen, it is important to identify persistently infected boars. However, even for boars given the same PRRSV strain and dose, variability in the duration of viral shedding in semen has been observed, suggesting that host factors are involved in PRRSV persistence. To determine whether there are host genetic factors, particularly litter and breed differences related to the persistence of PRRSV, 3 litters from 3 purebred swine breeds were used for this study. It was also determined whether PRRSV could be detected for a longer period of time in serum, semen, or peripheral blood mononuclear cells (PBMC) and if PRRSV could still be detected in tissues after these antemortem specimens were PRRSV negative for a minimum of 2-3 weeks. Three Hampshire, 3 Yorkshire, and 2 Landrace PRRSV-naive boars were obtained and inoculated intranasally with a wild-type PRRSV isolate (SD-23983). All boars within each breed were from the same litter, and litters were within 9 days of age. Serum and PBMC were collected twice weekly from each boar and analyzed for the presence of PRRSV by virus isolation and the polymerase chain reaction (PCR). Serum was also used to obtain virus neutralization titers and enzyme-linked immunosorbent assay S/P values. Semen was collected twice weekly from 7 of 8 boars and analyzed by PCR. After all specimens were PRRSV negative for a minimum of 2-3 weeks, each boar was euthanized, and 21 tissues plus saliva, serum, feces, and urine were collected. All postmortem specimens were evaluated by virus isolation. Specimens that were PRRSV negative by virus isolation were then evaluated by PCR. The mean number of days (+/-SD) for the duration of PRRSV shedding in semen was 51+/-26.9 days, 7.5+/-4.9 days, and 28.3+/-17.5 days for Landrace, Yorkshire, and Hampshire boars, respectively. Because of small sample sizes and large SDs, the differences in duration of PRRSV shedding in semen between breeds were not considered significant. However, the trend suggested that Yorkshire boars were more resistant to PRRSV shedding in semen than were Landrace boars, requiring further investigation using a larger numbers of boars. PRRSV was detected for a longer period in semen than in serum or PBMC in 4 of 7 boars. Viremia could be detected for a longer period in serum than in PBMC in 6 of 8 boars. After a minimum of 2-3 weeks of PRRSV-negative serum, semen, and PBMC, PRRSV could still be detected in the tonsil of 3 of 8 boars by virus isolation, indicating that boars still harbor PRRSV within the tonsil even though antemortem specimens are PRRSV negative.     

猪PLSCR4基因外显子区PCR-RFLP遗传多态性分析

本研究利用PCR-RFLP技术对我国6个地方猪种、中国野猪以及杜洛克、约克夏和长白3个国外猪品种,共307头猪的磷脂爬行酶基因(PLSCRs)外显子区的遗传变异进行了研究。结果表明:PLSCR4第7外显子处存在T68C的同义突变,第8外显子处存在G4A的错义突变;在T68C突变位点处,杜洛克、约克夏、长白猪、二花脸、五指山和民猪6个猪群优势等位基因为T,荣昌和野猪群体中优势等位基因为C;在G4A突变位点处,杜洛克、约克夏、长白猪、二花脸、五指山和民猪群体中优势等位基因为G,藏猪、荣昌、金华及野猪群体中优势等位基因A。     

Incidence of boar taint in Swedish Landrace and Yorkshire boars

Boar taint in 500 Swedish Landrace and Yorkshire boar carcasses was tested by smelling fat samples heated on the tip of a soldering iron at 150°C. About 40% of the boars were scored as non-tainted; in another 40%, the judges were unsure whether taint was present or not. Boar taint was judged present in only 20% of the boars.The effects of weight and sex on boar taint were studied in approx. 275 boars, barrows and gilts slaughtered at 70, 90, 110 and 130 kg live weight. The number of boars scored as tainted increased with weight, but weight did not affect the level of taint in all boars. When the taste of boar meat and fat was compared to castrates, no differences were found in 80% of comparisons at 70 or 90 kg.The effect of weight on boar taint was studied in 69 boars reared on ad libitum or restricted feed. Biopsies were taken, by a needle biopsy technique, at 70, 90 and 100 kg live weight. The incidence of boar taint did not increase from 70 to 100 kg when boars were on restricted feed, but the weight effect was significant and linear at the ad libitum feeding level. The cause was probably an interaction between physiological development, age and weight of the boars.     

Production traits of litters in 2 crossbred Duroc pig lines

Genetics of different pig lines affects litter size, birth weight, and neonatal losses. Low birth weight has long been associated with neonatal losses, but piglet body mass index is reported to show stronger correlation with stillbirth. The aim of this study was to investigate differences in litter size, number of stillborn piglets, piglet BW gain, and body mass index between 2 different Duroc crossbred lines. Landrace × Yorkshire sows in 2 farms (n = 89) were divided into 2 groups on each farm. One group of sows on each farm was inseminated with semen from Landrace × Duroc boars (boar group LD, n = 48), and the other was inseminated with semen from purebred Duroc boars (boar group DD, n = 41). Piglets were monitored from birth to weaning at the age of 5 wk. Litter size in boar group LD was larger than in boar group DD (P = 0.03). Number of stillborn piglets in boar group LD tended to be greater than in boar group DD (P = 0.07). Piglets in boar group DD had a greater BW at birth (P = 0.02) and at 3 wk (P = 0.01) than those in boar group LD. Body mass index from birth to weaning was greater in piglets in boar group DD vs. LD (P < 0.01), and both BW and body mass index of liveborn piglets at birth for both groups combined showed a positive correlation with survival at weaning (P < 0.01). In conclusion, breeding for larger litter size in boar group DD may be one approach to increase the number of vigorous piglets in production, but the inverse relationship between litter size and birth weight was more pronounced for this group than for boar group LD (P = 0.03). Further studies of the impact of litter size on BW gain are necessary before a final conclusion can be reached.     

黄芪多糖对猪精液冷冻保存效果的影响

为了评价黄芪多糖（Astragalus polysaccharides）对外来公猪精液冷冻保存的影响情况,为猪精液冷冻稀释液配方的改良提供理论依据,试验采集美系长白、大约克与杜洛克3种公猪的精液,用添加不同浓度（0、0.01%、0.02%、0.03%、0.04%、0.05%、0.06%）黄芪多糖的冷冻稀释液稀释,0.25 mL塑料细管分装并冷冻,测定解冻后精子活力、畸形率及顶体完整率,并进行相同浓度3种公猪之间和同种公猪不同浓度之间的比较。结果表明,在相同黄芪多糖浓度下,仅杜洛克公猪冻后精子顶体完整率在不添加黄芪多糖时显著高于大约克公猪（P<0.05）,其余均无显著差异（P>0.05）;每种公猪的最佳黄芪多糖添加浓度均为0.04%,在该浓度下精液冻后质量均显著优于对照组（P<0.05）;各种公猪最佳黄芪多糖添加浓度下的精液冻后质量指标之间均无显著差异（P>0.05）。总之,稀释液中添加0.04%黄芪多糖在长白、大约克与杜洛克3种公猪的精液冷冻都可以取得较好的效果。