对牦牛和普通牛种间杂种公牛精子生成水平的研究

本文对牦牛和普通牛种间杂种公牛睾丸组织及电刺激所采精液进行了观测。结果表明,种间杂种公牛随代数增加,睾丸逐渐恢复产生精子的机能。种间杂种3代公牛有的可产生形态正常的精子。种间杂种3代是可育或不育(不能产生精子)的临界代。     

纳罗克非洲狗尾草种子产量因子与产量的通径分析

采用多因素裂区试验设计,通过大样本相关、通径和逐步回归分析后,结果表明,纳罗克非洲狗尾草Setaria sphacelata cv. Narok的6个种子产量因子对种子产量的直接贡献大小排序为：x4（单位长度小花数）>x6（千粒重）>x1（花序长）>x2（单位面积生殖枝数）>x3（单位长度小穗数）>x5（单位长度种子数）,说明提高单位长度小花数、千粒重和花序长是最有效提高纳罗克非洲狗尾草种子产量的途径,其次提高单位长度小穗数、单位长度小花数和单位面积生殖枝数。     

不同秋眠级苜蓿品种数量性状的相关分析

对25个不同秋眠级苜蓿品种的11个农艺性状和5个生殖性状进行相关分析,并对其鲜草产量和种子产量的构成进行回归分析。结果表明:受秋眠级直接影响的性状有鲜草产量、株高、主茎长、茎节数、叶面积、叶长、叶宽和越冬率等8个性状,其中产草量与秋眠级呈显著正相关,相关系数0.806,越冬率与秋眠级呈极显著负相关,相关系数-0.957,其余6个性状与秋眠级均呈极显著正相关,相关系数依次为叶面积0.995、主茎长0.987、叶长0.983、株高0.940、茎节数0.900、叶宽0.885;所测苜蓿的5个生殖性状,均与秋眠级呈极显著负相关,相关系数依次为生殖枝数-0.959、种子产量-0.958、荚果数/生殖枝-0.954、千粒重-0.943、种子数/荚果-0.859。     

Comparing accuracy of fish sperm motility measurements obtained from two computational extremes in tracking approaches: Nearest neighbor and multiple hypothesis tracking

We conducted a study to assess the accuracy of nearest neighbour (NN) and multiple hypothesis tracking (MHT) methods—which are opposite extremes in computational complexity—in determining the percentage of motile sperms and the number of sperms tracked in simulated data of fish sperm movements, and to evaluate the resulting number of tracking errors and analysis duration. Sperm tracking and swimming path assembly were assessed in 36 video clips (1 s length at 100 fps) of emulated Rhamdia quelen sperm kinetics at different densities (50, 100, 200 or 300 spermatozoa in the field of view) and motility rates (30, 60 or 90%). The MHT method accurately estimated the percentage of motile sperms, whereas NN underestimated it by up to 6.59%. Increase in sperm density reduced the number of sperms tracked from both trackers. With more than 50 sperms in the field of view, NN and MHT tracked 73% and 92% of the ground-truth sperm count, respectively. Both trackers showed a quadratic increase in tracking errors with increasing sperm density. The maximum percentage of errors at 90% motility was 12% for NN and 4.7% for MHT. The MHT tracker required up to 150 s to track 300 sperms, whereas NN completed the tracking procedure in less than 0.5 s. On maintaining a density of up to 100 sperms in the field of view, it was possible to obtain high accuracy, low number of tracking errors and an acceptable analysis duration with both tracking methods.     

行距对“川草2号”老芒麦生殖枝及种子产量性状的影响

试验对30,45,60,75,90 cm五个行距下,老芒麦枝条性状、花序性状、种子产量性状进行比较分析,结果表明,行距首先通过对分蘖数、生殖枝比例、生殖枝数/m²、生殖枝高度、生殖枝直径等有极显著影响,继而造成穗柄长、穗柄直径、穗轴长、小穗数/生殖枝、小花数/生殖枝等差异极显著,最终导致结实率、表现种子产量与实际种子产量的差异;单位面积小花总数、潜在种子产量受行距影响不大且趋于稳定;偏相关分析说明,在行距恒定时,株高是影响结实率的主要因素,花穗柄长度反映小穗数/生殖枝、种子数/生殖枝与实际种子产量,可通过株高与花穗柄长度预测结实率与种子产量;千粒重与其他参数相关性低,是相对稳定的种子性状;行距60 cm时,潜在种子产量、表现种子产量和实际种子产量最高,适宜在生产中推广。     

Evaluation of the motility of boar sperm using computer technics

The motility of the spermatozoa of a normally fertile boar was measured by means of the Cellsoft Computer Automated Semen Analyzer. The following values were obtained for the chosen parameters: average speed of motion (V) 20.842 microns per second, average linearity (L) 4.960, average amplitude of lateral deflection of the head (LPH) 0.90 microns, frequency of average path intersection (FPD) 11.44 s. There were 46 spermatozoa with circular motion (27.71% of motile sperms). The majority of the spermatozoa (52%) moved at the rate of 10 to 20 microns.s-1, and linearity was most frequently in classes 3 to 4 (16%). The Semen Analyzer has brought progress in the evaluation of sperm motility; hence, the apparatus should be recommended for use in State Animal Enterprises and their A.I. stations.     

An assessment of the most profitable length of lactation for producing piglets of 20 kg body weight

Based on data derived from experiments and surveys carried out in several countries, the most profitable length of lactation for producing piglets of 20 kg body weight is assessed. The assessment is limited to a comparison of the numbers of piglets (20-kg) produced per sow per year at lactation periods varying from 6 to 56 days with the associated amounts of sow and piglet feed consumed and its costs. For the various lactation periods considered, several equations are used to estimate the numbers of 20 kg piglets produced and the amounts and costs of sow and piglet feed consumed per piglet raised to this body weight. According to the assessment, and taking into account reasonable piglet prices, the margins over feed costs per sow per year are highest with a lactation period of 21–25 days.     

猪体外受精中钙调控机理研究

本研究探讨了猪精子体外获能、卵母细胞成熟和受精过程中钙调控机制,并用X射线微分析仪,测定了钙的含量变化和分布状态.结果发现,猪精子获能后,质膜表面钙含量降低,而顶体内部钙升高,并诱发顶体反应,发生囊泡化;中段线粒体基质内的钙较获能前高;A类卵母细胞经体外成熟培养后,其质膜上钙含量升高,而B、C类卵母细胞钙变化却降低.卵子受精后,质膜上钙含量明显升高,分布状态也发生相应变化,受精后20h,质膜上的钙呈集团分布.     

Relationship between the number of sperms and the rate of implantation in bitches inseminated into unilateral uterine horn

Studies were made on the number of sperms required for fertilization of ova ovulated from the bilateral ovaries in bitches. The experiment was carried out with 44 female beagles, which were divided into four groups of seven to eleven bitches each. The four groups were inseminated with 40 X 10(6) sperms/0.2 ml, 20 X 10(6) sperms/0.1 ml, 10 X 10(6) sperms/0.1 ml, and 3-5 X 10(6) sperms/0.1 ml, respectively. All the bitches were laparotomized at an optimum time for mating and inseminated at the tip of the horn of an unilateral uterus. In the four groups conception took place at a rate of 7/7, 8/8, 10/11, and 2/7, respectively. The number of puppies exceeded the number of ova ovulated on the inseminated side at a rate of 5/7, 6/8, 0/10, and 0/2 in the four groups, respectively. Therefore, it was clarified that when more than 20 X 10(6) sperms/0.1 ml were inseminated in the ipsilateral uterine horn, ova ovulated on the contralateral side were fertilized also. Then a unilateral ovary was ovariectomized in 11 bitches, which were inseminated with 10 X 10(6) sperms/0.1 ml in the ipsilateral uterine horn. As a result, only one bitch became conceptive and gave birth to only one puppy. From these results, it was considered that 10 X 10(6) sperms/0.1 ml may be most adequate for the ova on the side of insemination alone to be fertilized.     

摩托车尾气对小鼠睾丸组织形态的影响

为研究摩托车尾气对小鼠睾丸形态的影响,用不同摩托车的尾气染毒小鼠4周后,取出睾丸制成组织切片,观察并分析睾丸组织结构的变化.结果表明,试验组睾丸生精小管内的生精细胞变得很稀疏,管腔内发现畸形精子,且精子数量减少,并有出血现象.生精小管之间的结缔组织结构变薄且不完整,其间质细胞也明显减少.还发现不同种类摩托车的尾气,对睾丸组织结构的影响也不同.     

The effect of veld-burning on the seasonal abundance of free-living ixodid ticks as determined by drag-sampling.

A supervised veld-burn in the Sclerocarya caffra/Acacia nigrescens Savanna landscape zone in the south-eastern region of the Kruger National Park was carried out during September 1988. The effect of the fire on the free-living tick population was determined by comparing the numbers of ticks collected by monthly drag-sampling in the burnt zone with those collected in an adjacent unburnt zone over a 2-year period. A total of 13 ixodid tick species were involved. Tick numbers were reduced after the burn but rose again after varying periods of time. The length of these periods depended upon a number of variables. These included tick species, patterns of seasonal abundance, and host preferences. The original reduction in numbers seemed to result in subsequent cyclical population fluctuations and in some instances overcompensation was noted. Veld-burning as a control technique may be effective with tenuously adapted tick species or reduced populations and may be enhanced by the exclusion of major hosts for a critical period after the fire.     

使用荧光染色和流式细胞术检测山羊精子

分别使用PI(碘化丙碇),FITC-PSA(异硫氰酸荧光素络合豌豆凝集素)和RH123(罗丹明)对山羊冷冻精子进行染色,再使用流式细胞仪进行检测、分析。试验发现,对于山羊的冷冻精子,PI染色阴性的为质膜完整的精子;FITC-PSA染色阴性的可能为顶体完整的精子,染色FITC-PSA+和FITC-PSA++,可能分别为顶体反应中的精子和顶体破损精子;RH123+应为线粒体无活性精子,有绿色荧光可能是因为染料残留在细胞膜上导致,而RH123++可能应为线粒体有活性的活精子。不同个体羊的精子对于低温敏感度不一样。不同个体羊之间的冻精顶体完整率、质膜完整率、线粒体有活性的精子比率之间差异显著,据此应选择合适的山羊个体进行精液冷冻。     

Changes in structure of the limiting membrane and in oxygen permeability of the chicken egg integument during incubation

1. Oxygen permeabilities (K_O2 ) of the shell and shell membranes of fertile and infertile chicken eggs were measured at 37.5 °C and a relative humidity of 0.60 throughout 14 d incubation, with turning. The K_O2 of the shell and membranes of infertile eggs was around 1.0 × 10^?7 cm³ O₂STP sec^?1 cm^?2 Torr^?1 (1 Torr = 133.322 Pa) throughout incubation. With fertile eggs, from which there was a linear loss of water during incubation, the K_O2 of the shell and shell membranes was about 1.0 × 10^?7 cm³ O₂STP sec^?1 cm^?2 Torr^?1 for the first four days of incubation. Thereafter the majority of shells and membranes had a K_o2 of about 1.0 × 10^?6 cm³ O₂STP sec^?1 cm^?2 Torr^?1.

2. A diminution of the Na⁺ and K⁺ content of the shell membranes of fertile eggs was not associated with changes in the dimensions of the glyco‐protein mantle on the cores of the individual fibres of the membranes. There was, however, a progressive deterioration in the limiting membrane of fertile but not of infertile eggs.

3. It was concluded that changes in the O₂ resistance of the integument of fertile eggs were not a product of change in either of the shell membranes but of damage caused to the limiting membrane by the chorioallantois.     

Impacts on conceptus survival in a commercial swine herd

An estimated 30 to 40% of potential piglets are lost before farrowing in U.S. or European pig breeds. Because these studies were conducted in limited numbers of university research herds, we decided to characterize the timing, pattern, and extent of conceptus loss in a commercial swine herd in Iowa (Pig Improvement Company; Camborough Line). Sows (parities 2 to 14) were slaughtered on d 25 (n = 83), 36 (n = 78), or 44 (n = 83) of gestation. These days coincide with periods before, during, and after uterine capacity becomes limiting to conceptus survival. At slaughter, numbers of corpora lutea (CL) and uterine horn length were determined, and conceptuses were removed and evaluated. Uterine horn length and CL number did not differ among these days of gestation, averaging 217 cm and 26.6 CL, respectively. In contrast, numbers of conceptuses decreased (P < 0.05) from 15.8 on d 25 to 12.9 on d 36, then remained relatively constant through d 44 (12.1). Thus, conceptus survival averaged 60.2% on d 25, 50.1% on d 36, and 46.3% on d 44, based on numbers of CL present. There was a positive correlation (P < 0.001; r = 0.50) between numbers of viable conceptuses on d 25 and ovulation rate, but this association was completely lost by d 36 (P > 0.10) when uterine capacity becomes limiting. In agreement with this premise, uterine horn length and conceptus number were not associated on d 25 but exhibited positive correlations (P < 0.05) on d 36 (r = 0.36) and d 44 (r = 0.40). On all 3 d examined, the numbers of viable conceptuses were not associated with fetal weight but were negatively correlated (P < 0.05) with placental weight. Compared with the commonly reported values for ovulation rate and percentage conceptus loss in university research herds, values from these production animals were extremely high. Data suggest that throughout this period, larger litters were associated with conceptuses exhibiting small placentae. These data lend support to the concept that increased placental efficiency (fetal weight/placental weight) may contribute to increased litter size in the pig.     

Sperm Motion Characteristics of Garole Rams Raised for a Prolonged Period in a Semi-arid Tropical Environment

The Garole is a prolific but less well known and rare breed of small sheep found in the hot and humid Sunderban region of West Bengal. An ability to breed throughout the year and to graze in knee-deep water, resistance to foot rot and a strong mothering instinct are some of the special features of this breed. Garole rams could provide germplasm to incorporate prolificacy traits by artificial insemination of the nonprolific sheep breeds found in abundance in the semi-arid and arid tropical climates of India. The aim of the present study was to evaluate the semen production by Garole rams maintained in a semi-arid climate for three years and to objectively assess their semen quality by a computer-assisted sperm analysis technique. The donor rams were randomly selected each year from the original flock procured from their natural habitat or from the offspring born at the Institute farm. Semen was collected weekly for three weeks each autumn for three consecutive years from 8 rams each year. The overall means (SD) of the traits that did not differ significantly with age or year were volume, concentration, curvilinear velocity, average path velocity, amplitude of lateral head displacement, beat frequency, motility and the percentages of rapid motile sperms and of slow motile sperms. The age of the rams had a significant effect (p<0.05) on the straight-line velocity but this was not significantly affected by the length of exposure to the semi-arid climate. However, the age and year had significant effects (p<0.05) on linearity, straightness and the percentage of medium motile sperms. It was concluded that Garole rams are capable of producing good-quality semen even after a prolonged period of exposure to a semi-arid tropical climate.     

氮肥对垂穗披碱草种子产量和质量的影响

2001-2002年研究氮肥对垂穗披碱草(Elymus nutans)种子产量和质量的影响。结果表明:施氮量以120 kg/hm²(秋60+春60)的效果最好,种子产量达1856 kg/hm²;施氮肥可提高生殖枝数、小花数/小穗、可育小花数/小穗和种子千粒重,但对小穗数/生殖枝影响不显著;施氮肥能提高早期成熟种子的发芽率、芽长、芽重及酸性磷酸脂酶的活性。     

精浆对猪精子冷冻效果影响的研究

为优化猪精子冷冻技术,提高解冻后精子的活力和受精能力,本试验分别以含精浆浓度为10%、20%和30%的冷冻保护剂处理精子,以冷冻前、解冻后精子活力和质膜完整性,解冻后精子进行体外受精(IVF)的卵裂率和囊胚率等作为检测指标,同时以含有卵黄的Tris-柠檬酸－葡萄糖(Tris-citric acid-glucose,TCG)冷冻基础液作为对照研究精浆对猪冷冻精子的保护作用。结果显示,在含有10%精浆浓度的稀释液中,冷冻前质膜完整性,解冻后精子活率、质膜完整性、IVF囊胚率相对于对照组均显著提高(P<0.05);当含有10%精浆的冷冻精液解冻后用于人工授精时,与配母猪妊娠率、窝产仔数、窝产活仔数等仍显著低于鲜精授精组(P<0.05)。上述结果表明,含10%精浆的冷冻保护剂能提高精子的冷冻后活力和IVF胚胎发育率,但用于人工授精配种与鲜精相比还有一定差距。     

Hydrophobic silicone elastomer chamber for recording trajectories of motile porcine sperms without adsorption

Motile porcine sperms adhere to hydrophilic materials such as glass and plastics. The adsorption of sperms to a hydrophobic poly(dimethylsiloxane) (PDMS) membrane is less compared with that to glass. We investigated the linear velocity (LV) and amplitude of lateral head displacement (ALHD) of motile porcine sperm on glass and PDMS preparations using computer-assisted sperm analysis (CASA). Significant decreases were observed in the 15-min LV (P<0.05) and ALHD (P<0.05) in motile porcine sperm on glass preparations compared with those on PDMS preparations. These differences were due to adsorption of the head and/or neck to hydrophilic substrates. Because of the elasticity of PDMS, we propose that a PDMS membrane should be used for CASA. To investigate the dynamics of motile porcine sperms with microfluidics, we do not recommend plasma treatment to bond PDMS and glass in the microchannel preparation; instead, we suggest that a PDMS molding process without plasma treatment be used for preparation of microfluidic channels.     

不同稀释液对公猪精液常温保存效果的研究

 为提高猪精液的保存效果,设计了3种常温保存稀释液配方,并对保存后的精子进行了顶体染色,为猪精液常温保存技术及稀释液配方的研究提供参考依据。结果表明：当精子活率为50％与30％时,配方Ⅱ的精子保存时间均显著高于（P<0.05）配方Ⅰ与配方Ⅲ,且配方Ⅱ所保存精子的总存活时间也显著高于（P<0.05）配方Ⅰ与配方Ⅲ;在精液保存24h后,3种配方保存的精子顶体完整率均在95％以上,且差异不显著（P>0.05）,配方Ⅱ对精子的常温保存效果要优于配方Ⅰ与配方Ⅲ。     

Excess polyspermy reduces the ability of porcine oocytes to promote male pronuclear formation after in vitro fertilization

Male pronucleus (MPN) formation is a very important physiological event during fertilization, which affects in vitro production of transferrable embryos. The aim of this study was to find out the correlation between the number of penetrated sperm and the occurrence of failure of MPN formation in porcine oocytes. In vitro matured porcine oocytes were fertilized in vitro with frozen epididymal sperm. Two different frozen sperm lots were tested in this study, which were different in terms of polyspermy rates. The numbers and the status of penetrated sperm in oocytes were evaluated 10 h after insemination. Under high polyspermy condition, the polyspermy rate was 83.5% with an average mean of 3.5 sperms per penetrated oocyte, whereas the percentage of polyspermy was 65.5% with an average mean of 2.4 sperms per penetrated oocyte under moderate polyspermic condition. Correlation analysis revealed a negative correlation between the number of penetrated sperm and their MPN formation percentage both in the sperm lot of high polyspermy (R = −0.560, p < 0.05) and in the sperm lot of moderate polyspermy (R = −0.405, p < 0.05) which suggests that penetration of excessive spermatozoa disables the oocyte cytoplasm to promote MPN formation.