A comparison of progeny sired by high and low indexing Hampshire and Duroc central test station boars: progeny performance

A 2-yr study compared progeny performance of high (HI) and low (LI) indexing central test station boars purchased in Iowa, Missouri, Nebraska and Oklahoma. Boars were evaluated for a National Swine Improvement Federation index recommended for central test stations. The 1st yr 22 Hampshire boars were mated to three- and four-breed Duroc, Yorkshire, Landrace and Spotted cross gilts. A disease outbreak the first farrowing season caused severe death loss and reduced performance. From 198 litters, 826 pigs completed their gain test. The 2nd yr 23 Duroc boars were mated randomly to gilts produced the previous year. From 181 litters, 1,070 pigs completed their gain test. No differences existed for postweaning average daily gain (ADG) and probe backfat thickness (PBF); however, progeny sired by HI Hampshire boars were an average of 5.66 units better for the index (I) compared with progeny of LI Hampshire boars. Gilt progeny of HI Duroc boars were .03 kg, .79 mm and 3.93 units greater for ADG, PBF and I, respectively, than LI Duroc-sired gilts. Barrow progeny of LI Duroc boars gained .01 kg/d faster, had .59 mm more PBF and were no different for I than barrows sired by HI Duroc boars. Maternal grandsire effects were important for Duroc-sired pigs, with gilts of HI maternal grandsires having .01 kg faster ADG, yet barrows of HI maternal grandsires had .02 kg slower ADG as compared with gilts and barrows having LI maternal grandsires, respectively.     

Prediction of performance of progeny from test station boars.

Data were obtained from 1,954 Duroc and 2,252 Yorkshire purebred and crossbred progeny sired by 34 Duroc and 32 Yorkshire boars, respectively. Boars were purchased from the North Carolina Swine Evaluation Station during August 1983 to December 1988. Boars were selected to represent high and low indexes at the test station. Progeny were raised and tested under conditions similar to commercial pig production at the Tidewater Research Station. For each breed of boar (Duroc and Yorkshire), breed type (purebred and crossbred), and sex (castrates and gilts) of progeny, regression coefficients of progeny traits on each sire trait were computed. Progeny traits were ADG, days to 104.3 kg BW (DAYS), backfat thickness (BF), and feed conversion ratio (FC). Sire traits were ADG, DAYS, BF, FC, and INDEX. Effects of boar test group and progeny test group were included in the models. Averaged over breed type and sex, a 25-unit (1 SD) increase in sire INDEX resulted in 14.5 g more ADG, 3.2 fewer DAYS, .57 mm more BF, and .017 lower FC in Durocs and 5.6 g more ADG, .01 more DAYS, .81 mm less BF, and .083 lower FC in Yorkshires. The low magnitude and variable signs of some regression coefficients suggested that predictions of progeny performance from performance of individual sires at the North Carolina Swine Evaluation Station were not very reliable. Differences between regressions for purebreds and crossbreds implied small correlations between the two breed types. Differences between Durocs and Yorkshires indicated that genetic parameters might not be the same for the two breeds.     

A comparison of different methods of extraction of the M-protein from Streptococcus equi.

The molecular weights of the proteins produced in different extracts of Streptococcus equi were compared on immunoblots with antisera against acid extracted and mutanolysin extracted M-protein. Acid and alkaline extracts of S. equi contained some peptides of similar molecular weight that reacted with antiserum against an acid extracted 41,000 m.w. fragment suggesting that these fragments contained common epitopes. Comparison of the amino acid compositions of the 35,000 m.w. fragment of the alkaline extract and the 41,000 m.w. fragment of the acid extract suggest that these immunologically reactive fragments were probably derived from the same protein. Little cross-reactivity was observed between antisera against S. equi acid extracted protein and the native 58,000 m.w. M-protein. This suggests that conformational epitopes on the native M molecule are not present after acid treatment.     

南酸枣不同嫁接方法对比试验

采用船形芽腹接、小芽腹接、段芽接、段枝接和单芽切接（对照）五种不同嫁接方法对比试验表明：处理Ⅰ(船形芽腹接法)的成活率比对照高14.8%、达极显著水平;处理Ⅳ(段技接法)的成活率比对照低24.5%。春季船形芽腹接法能有效提高嫁接成活率和苗圃出苗率。     

A comparison of two different methods for dead space measurements in ventilated dogs

The aim of the study was to compare two methods of measuring physiological dead space/tidal volume ratio (Vd /Vt ) and alveolar dead space (Vd _ALV). Measurements were obtained by automated single breath CO₂ analysis (Ventrak 1550/Capnoguard 1265 (V&C)) and classical calculations were carried out using the Enghoff–Bohr equation in anaesthetized dogs. The V&C consists of a mainstream capnometer, a pneumotachometer, a signal processor, and computer software to determine continuous single‐breath CO₂ analysis (SBT‐CO₂). Eleven dogs of mixed breed (five female, six male) mean body mass 35 ± 10 kg, aged 9 months to 8 years were studied. Pre‐anaesthetic medication was acepromazine (0.03 mg kg^?1) and methadone (0.1 mg kg^?1). Anaesthesia was induced with propofol given to effect and maintained with propofol (10 mg kg^?1 hour^?1) and fentanyl (0.02 mg kg^?1 hour^?1) by infusion. The dog's trachea were intubated and the carbon dioxide and flow sensor were placed between the tube and the Y‐piece of a circle system (Fi O₂ = 1.0). Controlled ventilation was started (tidal volume 10–15 mL kg^?1) and settings were not changed throughout the measurement period. Mixed expired PCO₂ (P e ?CO₂) was measured by analyzing expired gas collected in a mixing box in the expiratory limb of the circle system. The dorsal pedal artery was cannulated for arterial blood sampling and analysis. Measurements were done every 15 minutes for 1 hour. The Vd /Vt was automatically calculated and displayed from the SBT‐CO₂ analysis and also obtained using the Enghoff modification of the Bohr equation (Vd /Vt = (PaCO₂ ? P e ?CO₂)/PaCO₂). Alveolar dead space was determined by calculating the physiological dead space (Vd phys = expired volume × (Vd /Vt )) and subtracting the anatomical dead space measured by SBT‐CO₂. Values for Vd /Vt and Vd _ALV obtained with both methods were compared using Students t‐test. The mean values from the automatic dead space calculation (Vd /Vt : 0.62–0.63; Vd _ALV: 56.1–64.3 mL) did not differ significantly from those calculated arithmetically (Vd /Vt : 0.62–0.63; Vd _ALV: 54.09–66.31 mL). The mean differences and standard deviation in Vd /Vt was 0.63 ± 0.00 and in Vd _ALV 58.98 ± 4.28 mL for the two measurement techniques. Our data indicate that V&C can be used for accurate noninvasive online Vd /Vt and Vd _ALV measurements in anaesthetized ventilated dogs.     

猪三毛滴虫长春株不同染色方法的比较

将从长春地区腹泻仔猪盲肠中分离得到的猪三毛滴虫用1640培养基短期培养后,使用碘染色法、瑞氏染色法、姬氏染色法、姬氏-瑞氏复染法、Weigere铁苏木素染色法和鞭毛染色法染色分别对其染色,观察不同虫体形态结构,并比较了不同染色方法的染色效果。结果显示,姬氏染色、瑞氏-姬氏复染和鞭毛染色法对猪三毛滴虫染色效果较好,可获得虫体形态完整、结构清晰的染色标本。     

动物尿能值测定方法比较试验

<正> 动物尿能值是代谢试验必需的参数。尿能测定的准确性主要取决于所取干尿样的数量与燃烧时载体产热误差的大小。用冻干法冻干后则热、成本及设备要求高,用纤维吸附法易受载体产热误差的影响。我们过去是用定量滤纸作载体的滤纸吸附法,但效果仍不理想,每次燃烧时尿样热值与载体热值之     

Quantitative comparison of different purification and detection methods for Cryptosporidium parvum oocysts

Cryptosporidium parvum (C. parvum) is the causal agent of cryptosporidiosis in many animals, mainly cattle, and possesses a high zoonotic potential. It occurs worldwide and ubiquitously. Detection of C. parvum is mainly performed directly but purification of the oocysts is useful to increase sensitivity and to obtain oocyst material for further use. The study was designed to compare (a) three different direct diagnostic methods, namely modified Ziehl-Neelsen staining, carbol fuchsin staining and conventional PCR, and (b) three routine oocyst purification methods, in particular flotation with saturated sodium chloride solution, Sheather's sucrose solution and a Percoll(?) gradient. During comparison of purification methods, special regard was paid to the ability to separate morphologically intact oocysts from the morphologically degenerated fraction or viable from non-viable oocysts, respectively. Results: (a) Diagnostic methods: Most effective in C. parvum oocysts detection in calf faeces was PCR; carbol fuchsin and modified Ziehl-Neelsen stainings achieved comparable results. (b) Purification methods: Oocyst flotation using sodium chloride solution showed to be superior to Percoll(?) gradient centrifugation and sugar flotation in terms of purification quality, recovery efficacy (yield) and reduction of the proportion of degenerated or non-viable oocysts.     

Significance of two different ranking methods for studying fish fauna: a case study on the fish fauna from upper and middle portions from Mekong River

Studies on fish fauna should not only focus on fish composition and the comparison of fish composition among the study region and adjacent regions, but should also explore the origin and uniqueness of different taxa as well as the substitution of genera and species. In this study, the value of floristic presence method was modified and renamed the value of fish fauna presence (VFFP) method. The specific steps of the VFFP method and the traditional fish fauna analysis (TFFA) method were refined and standardized. Then, the VFFP and TFFA methods were applied to study the fish fauna of the upper and middle portions of the Mekong River basin. The results indicate that the TFFA method reflects the families (subfamilies) and genera that constitute the main body of fish in the studied river basin. The results of the VFFP method show which families (subfamilies) and genera are representative for the basin. Therefore, combining the TFFA and VFFP methods to analyze the composition of fish fauna can reflect the characteristics of fish fauna from different perspectives. The case study shows that the fish fauna of the Mekong River is a part of the fish fauna of Southeast Asia. Although it shows some similarities to the composition of South Asian fish fauna, it does not belong to the South Asian fish fauna as a whole, and is essentially different from the East Asian fish fauna. This study provides an objective, quantitative, and verifiable method for studying fish fauna.     

A comparison of the infectivity of Trichuris suis ova embryonated by four different methods

Four methods for embryonating the eggs of Trichuris suis in the laboratory were compared. Eggs were mixed with moist vermiculite (method 1) or were suspended in a 0.2% potassium dichromate solution that was either aerated (2), non-aerated (3) or deoxygenated (4). It was shown that differences in the method of culture profoundly affected the ability of the fully developed eggs to hatch and the parasites to become established in pigs. Of the four methods compared, ova of highest infectivity were produced after culture in moist vermiculite.     

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。     

Mycoplasma hyopneumoniae colonization of pigs sired by different boars

Differences in Mycoplasma hyopneumoniae colonization were evaluated in experimentally inoculated pigs sired by 3 different boars of the same genetic line. Forty-six pigs were used, including a treatment group and positive and negative control groups. The pigs were intratracheally inoculated with an M. hyopneumoniae suspension or with Friis media as a placebo. To evaluate differences in the magnitude of colonization during a 35-day period, nasal and tracheal swabs were collected weekly and tested by nested polymerase chain reaction (N-PCR). Temperature, weight and circulating antibodies were measured for 35 days. At 11 and 35 d postinoculation the pigs were necropsied and macroscopic and microscopic lesions were determined. A section of bronchus was tested by the indirect immunofluorescence test (IFAT), scanning electron microscopy (SEM) and N-PCR. The N-PCR results from the nasal and tracheal swabs showed that the pigs sired by one boar (B3) had a distinctive colonization pattern, different from that of the pigs from the other 2 boars and from the positive controls. SEM studies demonstrated that at 35 d postinoculation a higher proportion of B3 pigs had lower numbers of mycoplasmas attached to the cilia compared with B1 and B2 offspring. No significant differences were observed in temperature and weight gain among groups by ANOVA; however, with use of a 2 × 2 table, temperature differences were observed between pigs sired by boars B1 and B2 at 4 d postinoculation. No pigs seroconverted, showed gross or microscopic lesions, or had positive IFAT results. These results provide evidence of differences in patterns of colonization between pigs sired by different boars, suggesting a possible genetic effect.     

高效液相色谱测定棉酚方法的建立及不同棉酚脱毒方法比较

棉籽粕是一种非常有价值的蛋白质饲料,棉籽粕的有效脱毒可以提高饲料利用率。本试验建立了一种快速、准确测定棉籽粕游离棉酚的HPLC方法,并采用不同的脱毒方式对棉籽粕中的游离棉酚进行降解,筛选最优脱毒方法。结果显示:(1)HPLC法测定棉籽粕中棉酚含量,棉酚色谱峰出峰稳定性良好、分离效果好、峰型理想、灵敏度高,可以高效的检测棉酚含量;(2)不同处理方法对棉籽粕脱毒效果不同,棉酚脱毒率大小排序为:微生物法>硫酸亚铁法>尿素法>高温高压法。最优的方法为微生物法,酵母菌发酵48 h后的发酵棉籽粕棉酚降解率高达93.86%;化学法(硫酸亚铁法和尿素法)脱毒率为53.64%～78.18%,物理法(高温高压)脱毒率最低,为41.00%。     

三种检测禽副粘病毒2型(PMV-2)抗体方法的建立及其与HI方法的比较

建立了检测血清中禽副粘病毒2型（PMV-2）抗体的间接免疫荧光试验（IFA）、间接法酶联免疫吸附试验（ELISA）以及斑点酶联免疫吸附试验（Dot—ELISA）方法，并将三种方法同血凝抑制试验（HI）进行了比较。结果表明，建立的IFA、间接ELISA和Dot—ELISA等三种抗体检测方法其敏感性、特异性均很好，与HI方法相比，敏感性也大大增强。     

Use of blood culture medium enrichment for synovial fluid culture in horses: A comparison of different culture methods

Reasons for performing study: Standard methods for culturing equine synovial fluid (SF) are often unrewarding. Evidence‐based information on the relative efficiency of different systems used for optimisation of isolation of microorganisms from equine SF is lacking. Objectives: To compare the results of different culture systems performed in parallel on SF samples from horses clinically diagnosed with synovial sepsis. Methods: Synovial fluid specimens were collected between February 2007 and October 2008 from all horses admitted to a referral hospital that were clinically diagnosed with synovial sepsis and from control horses. Synovial fluid samples were cultured in parallel by: 1) direct agar culture (DA); agar culture after: 2) lysis‐centrifugation pretreatment (LC); 3) conventional enrichment (CE); 4) combined LC/CE; or 5) blood culture medium enrichment using an automated system (BACTEC 9050). Results: Ninety SF samples from 82 horses were included, together with 40 control samples. Seventy‐one of 90 samples (79%) were culture‐positive by using blood culture medium enrichment (BACTEC), which was significantly higher compared to all other methods. BACTEC enrichment was never negative while any of the other methods was positive. Although agar culture following LC and/or CE resulted in a slightly higher number of positive samples compared to DA, this difference was not significant. All control samples were culture negative by the 5 different techniques. Although the majority of samples containing isolates recovered without enrichment, culture results after BACTEC enrichment were available on the same day as for agar culture with or without LC (19/23 samples), while CE postponed recovery by at least one day in 20/23 samples. Conclusion: Blood culture medium enrichment is superior to other techniques for isolation of bacteria from SF of horses. The use of an automated system allows enrichment without substantially postponing recovery of microorganisms. Potential relevance: The efficient and fast isolation of microorganisms from infected SF by the BACTEC system allows for rapid susceptibility testing and a more appropriate antibiotic treatment.