Control of Campylobacter fetus in artificially contaminated bovine semen by incubation with antibiotics before freezing

Fresh, diluted semen containing 1.55 X 10(6) cfu/ml of Campylobacter fetus subsp. venerealis was incubated with 500 iu of penicillin, 500 micrograms of streptomycin, 160 micrograms of lincomycin and 300 micrograms of spectinomycin per ml at 35 degrees C for 0, 1, 2, 5, 10, 20 or 40 minutes. The semen was cooled to 5 degrees C, packaged in 0.25 ml French straws and then frozen in liquid nitrogen for 2 weeks. Immediately after thawing and removal of the antibiotics by centrifugation semen samples from each of the seven treatment groups were cultured as for C. fetus. Semen samples were also examined by in-vitro tests for sperm motility prior to and post-freezing. Incubation with the antibiotics for 5, 10, 20 or 40 min prior to freezing reduced the numbers of C. fetus in the semen to non-detectable levels in 38%, 69%, 88% and 100% of samples respectively. The incubated semen showed no significant reduction of sperm motility although fertility trials have not been done.     

猪冷冻精液的研究

本试验以甘油、乙二醇为抗冻剂，并添加ATP或安息香酸咖啡因，以解冻后精子活力、顶体完整率、顶体膨胀率、顶体破损率、尾部畸形率和在37℃下的存活时间几个重要评定指标为依据，筛选了几种猪颗粒冻精的冷冻稀释液配方，并优化了其冷冻程序。结果表明，与对照组相比，在冷冻液中添加0．1mg／ml的ATP或2mg／ml的安息香酸咖啡因都能显著提高解冻后精子活力(分别提高0．13和0．18)，降低顶体膨胀率(两者都将近降低了11％)，并能延长其存活时间(分别延长10．5h和11．8h)；甘油和乙二醇两种抗冻剂配合使用，将显著提高冻后精子的活力与存活时间，其较优混合量为甘油3％，乙二醇0．5％。     

The effect of temperature on survival of pathogenic bacteria in biogas plants

The paper deals with the hygienic advantages of sanitation to treat dairy manure in full‐scale biogas plants. The slurry samples were collected from two thermophilic biogas plants (55°C) and two mesophilic biogas plants (38°C) in Hokkaido Japan. A detectable number of Coli‐aerogenes group and Enterococcus in the slurries after anaerobic digestion (AD) could not be found in either thermophilic biogas plants. However, in both mesophilic biogas plants the viable numbers of Coli‐aerogenes group and Enterococcus were detected in the slurries even after anaerobic digestion. The mean decimation reduction time (T₉₀) values of the Coli‐aerogenes group and Enterococcus in the slurries during mesophilic digestion were 13.3 days and 16.7 days, respectively.     

The value of sexed bovine semen

Semen sexing may be used in a variety of practical situations, where part (or all) of the herd may be inseminated with X‐ and Y‐chromosome‐enriched semen. Expressions are presented to calculate the net present value of progeny derived from a semen dose, dependent on the values of females and males, and on the efficiency of sexing. Sexed semen allows selling a higher proportion of the more valuable sex and also increases the value of animals retained for breeding through more intense selection. The expressions to economically evaluate sexed semen are quite general but numerical examples are presented for several practical situations of interest in Brazil.     

奶牛乳房炎病原菌的分离鉴定和中药防治试验

奶牛乳房炎从发现至今的150多年中，一直是严重影响奶牛业健康发展的多发病之一。据报道，临床型乳房炎的平均发病率为33．41％，隐性乳房炎奶牛的平均头阳性率为73．91％。由于对食品卫生的严格要求，奶牛乳房炎已成为制约鲜奶加工龙头企业发展的突出问题。在病因学研究方面，认为奶牛乳房炎是多病因引起的一种疾病，但原发和继发细菌感染是主要病因之一，欧美国家多采用抗生素乳头注入疗法和全身疗法，由于抗生素在鲜奶中的残留已不被人们接受。以公英散为代表的内服中药制剂在治疗奶牛乳房炎方面取得了良好的效果。但内服制剂尚存在容易引起奶牛应激、食欲减退和生产性能下降等诸多问题。为此，我们对奶牛场的生产奶牛进行了乳房炎病原菌调查和分离鉴定，单味中药的抗菌性筛选和对不同组方和剂型的治疗试验研究，报告如下。     

Rapid freezing of bull semen in straws

Summary A method is described in which bovine spermatozoa, packaged in plastic straws, can be frozen rapidly with uniformofreezing rates. Best survival rates were obtained when straws were cooled from +5 °C to –120 °C in 180 seconds and then plunged into liquid nitrogen. This could easily be performed with the use of a specially constructed freezing box, in which flowing air was cooled to a temperature of –120 °C. Conception rates of over 400.000 first inseminations with semen frozen in this way, were satisfactory. Inhalt Schnelles Tiefgefrieren von Bullenspermien in Pailetten Es wird eine Methode zur schnellen Tiefgefrierung von bovinen Rinder-Spermatozoen, die in Plastikröhrchen verpackt sind, beschrieben. Mit dieser Methode können einheitliche Einfriergeschwindigkeiten erzielt werden. Beste Überlebensraten wurden erzielt, wenn die Röhrchen von +5° auf –120° innerhalb von 80 Sekunden heruntergekühlt wurden und dann in flüssigen Stickstoff getaucht wurden. Dies konnte leicht mit Hilfe einer speziell konstruierten Gefrierkammer erreicht werden, in der durchflieβende Luft auf eine Temperatur von –120° gebracht wurde. Konzeptionsraten von über 400 000 Erstbesamungen mit auf diese Weise tiefgefrorenen Samen waren zufriedenstellend.     

The concentration of estradiol-17 beta in bovine semen

This study was conducted to evaluate the influence of age, breed, epididymectomy and semen processing on the concentration of estradiol-17 beta (E2) in bovine semen. Semen was collected either by electroejaculation or with an artificial vagina. Neat semen samples were stored at -20 C until analysis. Processed, frozen semen and an egg yolk-citrate semen extender were obtained from a commercial semen processing firm and stored in liquid nitrogen at -196 C. The concentration of E2 in semen was determined by radioimmunoassay. Semen from mature (greater than 24 mo), fertile Brahman (n = 19), Brangus (n = 16), Charolais (n = 29), Holstein (n = 15) and Santa Gertrudis (n = 25) bulls was analyzed for E2 concentration, and no difference (P greater than .10) between breeds was found. There was no difference (P greater than .10) in seminal E2 concentration between mature, fertile bulls (n = 104) and epididymectomized bulls (n = 22). In semen collected from prepuberal (12 to 16 mo, n = 21), peripuberal (17 to 20 mo, n = 17) and mature (greater than 24 mo, n = 19), Brahman bulls, the mature bulls had a lower (P less than .01) semen E2 concentration than peripuberal and prepuberal bulls. There were no differences (P greater than .10) in seminal E2 concentration among peripuberal Angus (n = 8), Hereford (n = 8) and Brahman (n = 17) bulls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of storage effects in liquid preserved boar semen

Fertility of extended boar semen declines within the first 72 h of storage in vitro. Standard semen assessment, such as motility and membrane integrity, allows detection of lethal damage of spermatozoa. However, conventional sperm assessment often lacks standardization and does not allow identification of sub-lethal changes of sperm quality during the initial 72 h of storage. In the present brief review, recent strategies for quality assessment of liquid preserved boar semen are discussed and basic implications for experiments designed to detect storage effects are given.     

The survival of pathogenic bacteria and plant growth promoting bacteria during mesophilic anaerobic digestion in full‐scale biogas plants

The introduction of biogas plants is a promising way to recycle organic wastes with renewable energy production and reducing greenhouse gas. Application of anaerobic digestate as a fertilizer reduces the consumption of chemical fertilizers. In this study, the survival of pathogenic bacteria and plant growth promoting bacteria (PGPB) in two full‐scale biogas plants operated at mesophilic condition were investigated. Feedstock and anaerobic digestate samples were collected from biogas plants and bacteria load in samples were detected using standard dilution plate method. Pathogenic bacteria were reduced to not detected level through mesophilic digestion tank except for Campylobacter. However, it could be reduced by 98.7% through a sterilization tank. Bacillus was detected at 8.00 and 7.81 log₁₀ CFU/g dry matter in anaerobic digestates, and it was also resistant to sterilization tank. Bacillus spp. is considered to be the safe bacteria that hold remarkable abilities for promoting plant growth. The results showed that treatment at biogas plants is effective to reduce pathogenic bacteria in dairy manure, and sterilization could further reduce the sanitary risks of pathogenic bacteria relating to anaerobic digestate application. Anaerobic digestates could also be utilized as bio‐fertilizer as the high load of plant growth promoting bacteria.     

抗生素对猪精液常温保存效果的影响

采集9头公猪的精液（其中长白4头、大白4头、杜洛克1头）,对精液进行稀释后,分别加入9种抗生素,在18℃保存,测定精子保存时间和精子存活指数.结果表明：磺胺抗菌效果最好,其有效保存时间为4.38 d,精子存活指数为3.14.恩诺沙星、阿奇霉素、林肯霉素的抗菌效果次之,庆大霉素、青链霉素的抗菌效果再次之,新霉素、卡那霉素的抗菌效果最差.     

冀东地区奶牛隐性乳房炎病原菌的分离鉴定

通过LMT法、乳汁pH检验法和体细胞直接计数等方法相结合,对冀东地区3个大型奶牛场、8个奶牛养殖户选取的1 021头奶牛进行隐性乳房炎流行病学调查与病菌分离鉴定。结果表明,隐性乳房炎发病率为60.63%(619/1021),乳房炎阳性乳样品中细菌分离率达88.21%(546/619)。从543头隐性乳房炎患牛的阳性乳区乳样中分得细菌共4类14种菌82株,其中葡萄球菌36株,占43.90%;链球菌33株,占40.24%;肠杆菌类8株,占9.76%;棒状杆菌5株,占6.10%。冀东地区奶牛隐性乳房炎主要病原菌为金黄色葡萄球菌和无乳链球菌。     

Detection of leptospires in bovine semen by polymerase chain reaction

OBJECTIVE: In view of the considerable importance of venereal transmission of bovine leptospirosis, the objective of the present study was to compare the polymerase chain reaction (PCR), culture/isolation and serology to detect leptospire infection in bovine semen. DESIGN: Blood for serologic examination and semen for bacterial culture and PCR were collected from 20 bulls at artificial insemination centres in Brazil. Each animal was sampled twice for serology. RESULT: Forty-five percent (9/20) of the serum samples collected showed agglutinin titers to serovar hardjo in the first sample and 25% (5/20) had agglutinin titers to serovar hardjo in the second sample. Eighty percent (16/20) of semen samples were positive by PCR. Leptospires could not be isolated from any of the semen samples examined. CONCLUSION: Polymerase chain reaction can be a method of great potential for the detection of leptospires at artificial insemination centres.