Post-thaw viability of european bison (Bison bonasus) semen frozen with extenders containing egg yolk or lipids of plant origin and examined with a heterologous in vitro fertilization assay.

Basic characteristics of European bison (Bison bonasus) semen were described and the efficacies of two extenders-Triladyl, containing egg yolk, and a synthetic extender, containing soybean lipids-were tested for semen cryopreservation. Seven ejaculates were collected by electroejaculation from a 10-yr-old, European bison bull. Each ejaculate was diluted at 37 degrees C to a final concentration of 200 x 10(6) sperm/ml with Triladyl or the synthetic extender. Extended semen samples were frozen according to a standard bull semen freezing protocol. After 2 wk of storage, one straw from each extender and ejaculate was thawed, and postthaw quality was evaluated by individual sperm motility and movement rate, numbers of sperm morphologic abnormalities and intact acrosomes, functional integrity of the sperm membranes determined by hypoosmotic swelling test (HOST), viability (live-dead, eosin-nigrosin stain), and a heterologous in vitro sperm penetration assay (SPA). A total of 600 in vitro-matured bovine oocytes were inseminated with 1 X 10(6) spermatozoa of Holstein semen frozen-thawed in Triladyl (control) or of European bison semen frozen in Triladyl or the synthetic extender. Nuclear status of the oocytes was determined after 18 h of sperm-oocyte coincubation. Extender had no effect on any evaluated parameters of semen after dilution and cooling (4 hr at 5 degrees C) or in postthaw individual motility, quality of movement, and sperm morphology. However, significantly (P < 0.05) higher numbers of spermatozoa with intact acrosomes, intact membranes (HOST), and viable sperm (P < 0.01) were in semen frozen in Triladyl than in the synthetic extender. Mean values for heterologous SPA for bull (control) and for bison semen frozen in the synthetic extender were very much alike-63.3+/-10.6% and 63.1 +/- 15.9%, respectively; bison semen frozen in Triladyl was lower, 43.0+/-24.2% but not significantly different. Cumulative results from a variety of viability assays of diluted/cooled and frozen-thawed semen, including the heterologous SPA, suggest that European bison semen can be successfully frozen in both extenders tested in this study.     

Magnetic resonance imaging findings of bone marrow lesions in the equine distal tarsus

Three horses with sudden onset severe lameness were admitted for further diagnostic investigation. All horses had variable changes on radiographs in the distal tarsal region. Because of the sudden onset and severe degree of lameness, a magnetic resonance imaging (MRI) examination was performed. All horses showed areas of increased signal intensity in short tau inversion recovery (STIR) images involving the central and/or third tarsal bones. These lesions involved both the subchondral bone and bone marrow and are currently defined as bone marrow lesions (BML). Two horses were treated with shockwave therapy, one received intra‐articular medication. Two of the horses returned to previous athletic level and one is still in rehabilitation.     

细粒棘球蚴细胞系(13G-5)细胞代谢抗原的免疫原性和反应原性

应用培育成功的人源细粒棘球蚴细胞系(13G-5)细胞的天然代谢抗原,接种昆明小鼠,于接种后第14天给免疫小鼠接种人源细粒棘球蚴原头节约1 000 个,于200 d 剖检观察有无包囊形成,病理切片鉴定;并用该抗原作为诊断抗原,使用间接血凝(IHA)、琼脂扩散(AGD)试验,检测临床确诊的细粒棘球蚴病人血清。以多房棘球蚴病人血清、细颈囊尾蚴羊血清及正常人血清作为对照。结果表明,该抗原能使60% 的小鼠获得完全抵抗细粒棘球蚴原头节攻击的能力,未完全获得保护的小鼠形成包囊的数量、大小较对照组明显减少,且为不育囊;使用该抗原IHA 检测31 份血清,阳性24 份,阳性率77.42% ,AGD检测30 份血清,阳性13 份,阳性率43.33% ,2 种方法对多房棘球蚴病人血清和细颈囊尾蚴羊血清及正常人血清不起反应。     

Genetic variability of two Italian indigenous chicken breeds inferred from microsatellite marker analysis

1. The objective of this study was to determine the genetic structure and variability of Bionda Piemontese and Bianca di Saluzzo (Piedmont, Northwest Italy) using an international set of microsatellite loci (AVIANDIV-FAO). Differences compared with commercial lines and other Italian breeds were verified to justify the implementation of conservation programmes.

2. Flock contribution to genetic variability was assessed following the approach implemented in the MolKin software. Comparison was performed using the fixation index and the Reynolds genetic distance. The most likely number of different populations was estimated using the clustering procedure implemented in STRUCTURE.

3. The molecular information suggests that management practices could have prevented random mating and produced inbreeding and heterogeneity across flocks. In this respect, Bionda and Bianca show substructuring and are more similar to British breeds than other continental European breeds.

4. Bionda and Bianca fit into the European breeds provided with the highest number of alleles and expected heterozygosity. There is a clear distinction between the Piedmont breeds and the other populations. The Piedmont poultry differ from both commercial lines and other Italian breeds and retain a high level of genetic variability.

5. As for other indigenous breeds, Bionda and Bianca could make an original contribution to the industry in the future. A collective planned approach to restoration is essential, because the flocks are managed with poor regulation. Enhancing connection between breeders with an efficient replacement interchange and mating plan is the right way of controlling inbreeding, preventing substructuring and increasing variability within the flocks.

     

Breed identity and leadership in a mixed flock of sheep

The aim of this study was to analyze the breed identity and leadership in a mixed flock of sheep. The flock consisted of 89 Suffolk adult ewes and 250 Columbia ewes and 45 Columbia rams. The animals were kept in the pasture during the day. Each hour the flock was allowed to feed for 20 minutes, and then was moved for 40 minutes to a small paddock near the grazing area. In the afternoon, all sheep were taken to the night pen. The animals were observed for 120 days, 4 times a day (480 leadership breed positions), with respect to the following conditions: (1) leave pen at front of flock, (2) return to pen at front of flock, (3) first to move to the grassland, (4) return to the paddock, (5) drink first (on arrival time at the night pen), and (6) preference for an area in the night barn. The Suffolk breed were first in leaving (94% of the times) and in returning to the night pen (65%) (P < 0.05), and 35% returned with the Columbia sheep. The Suffolk breed were first to move to the grazing area (90%) and 10% moved with the other breed (P < 0.05). When returning to the rest area, the Columbia sheep were first to reach 54% of the time, the 2 breeds were together 29% of the time, and the Suffolk sheep were alone 17% of the time (P < 0.05). When comparing who drank first, 50% of the time both breeds went together, 28% of the time the Columbia sheep were first, and 22% of the time the Suffolk sheep were first (P < 0.05). At night, most of the Suffolk sheep had a preference for 1 barn area (P < 0.05). The results of our study suggest that most animals of each breed performed activities together. Suffolk sheep were leaders when moving to the grazing area and when selecting the place to rest.     

Multiplex real-time PCR SYBR Green for detection and typing of group III Clostridium botulinum

Clostridium botulinum type C and type D belonging to the group III organisms, are mainly responsible for animal botulism outbreaks. Clinical signs alone are often insufficient to make a diagnosis of botulism and a laboratory confirmation is required. Laboratory confirmation can be performed by demonstrating the presence of botulinum neurotoxins in serum, gastrointestinal contents, liver, wound of sick or dead animals, or by demonstrating the presence of C. botulinum in gastrointestinal contents, liver, and wound. Demonstration of spores in gastrointestinal contents or tissue of animals with clinical signs indicative of botulism reinforces the clinical diagnosis. With the aim of detecting and typing C. botulinum group III organisms, a multiplex real-time PCR SYBR Green was developed and in-house validated. Selectivity, limit of detection, relative accuracy, relative specificity, relative sensitivity, and repeatability of the method were investigated. The multiplex real-time PCR SYBR green used showed a 100% selectivity, 100% relative accuracy, 100% relative specificity, 100% relative sensitivity and a limit of detection of 277 and 580 DNA copies for C. botulinum type C and C. botulinum type D, respectively. The method reported here represents a suitable tool for laboratory diagnosis of type C and D botulism and for testing a large number of samples collected during the animal botulism surveillance and prevention activities.     

Assessing resistance against macrocyclic lactones in gastro-intestinal nematodes in cattle using the faecal egg count reduction test and the controlled efficacy test

The main objective of the present study was to evaluate the accuracy of the faecal egg count reduction test (FECRT) to assess the resistance status of ivermectin (IVM)-resistant isolates of the cattle nematodes Ostertagia ostertagi and Cooperia oncophora, using the controlled efficacy test (worm counts) as a reference. The second objective was to investigate whether both IVM-resistant isolates showed side-resistance against moxidectin (MOX) under controlled conditions. Thirty male Holstein calves were experimentally infected with 25,000 L3 of an IVM-resistant O. ostertagi isolate and 25,000 L3 of an IVM-resistant C. oncophora isolate. Twenty-eight days later the calves were randomly divided into 2 treatment groups and 1 untreated control group. Animals in groups 1 and 2 received MOX (Cydectin(?) 1%, Pfizer) and IVM (Ivomec(?) 1%, Merial) respectively, by subcutaneous injection at a dose rate of 0.2mg/kg bodyweight. Faecal samples were collected 7 and 14days after treatment and animals were necropsied 14/15days post-treatment. Both the FECRT and the controlled efficacy test demonstrated that the O. ostertagi and C. oncophora isolates were resistant against IVM, with efficacies below 90%. The IVM-resistant O. ostertagia isolate was still susceptible to MOX treatment, as shown by over 99% reduction in egg counts and worm burden. The FECRT suggested borderline resistance against MOX in the IVM-resistant C. oncophora isolate, with egg count reductions between 97% (95% CI: 76; 100) at day 7 and 86% (95% CI: 49; 96) at day 14. However, the controlled efficacy test clearly showed MOX-resistance, with a decrease of only 31% (95% CI: -12; 57) in C. oncophora worm numbers. After MOX treatment, a significantly lower number of eggs per female C. oncophora worms was counted compared to the control group (43% reduction). Due to this reduced fecundity, the FECRT may fail to detect MOX-resistance.