A novel Gammaretrovirus, named Koala retrovirus (KoRV) was identified in koalas in 2000. Subsequent testing has shown that KoRV appears to be widespread throughout the wild koala population in Australia. KoRV is apparently unique in that it is the only known example of an exogenous retrovirus which is actively undergoing the process of endogenisation. While there is currently little direct evidence that KoRV causes overt disease in koalas, it is possible or even likely that KoRV infection plays a significant role in the pathogenesis of various neoplasms and a variety of immunosuppressive disorders which are commonly diagnosed in koalas. It appears that KoRV may have arisen through the cross species transmission of a closely related retrovirus in a native Australian rodent, the grassland melomys. Both of these viruses are closely related to a third retrovirus, Gibbon ape leukaemia virus (GALV). GALV was first isolated in the late 1960's from captive gibbons in Thailand that were suffering from leukaemia. To date, the source of GALV remains unknown.

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The objective of the present study was to investigate factors associated with the risk of female pigs (females) becoming low lifetime efficiency sows (LE sows) in commercial herds. The factors investigated were age of gilts at first mating (AFM), number of services in parity 0 and pigs born alive (PBA) in parity 1. Farrowing records were obtained for 34,728 gilts entered into 101 commercial herds from 2001 to 2003. LE sows were defined as sows having lower 25th percentile of annualized lifetime PBA. AFM was categorized into six 21-day interval groups: 151-209, 210-230, 231-251, 252-272, 273-293 or 294-365 days. The PBA in parity 1 consisted of three groups: ≤ 7, 8-11 or ≥ 12 pigs. The number of services in parity 0 was categorized into two groups: non-returned to service or reserviced. Mixed-effects models were performed for statistical analyses. As AFM increased from the 151-209 to the 294-365 days, the proportions of females becoming LE sows correspondingly increase from 18.7 to 37.3% (P<0.05). The proportion of females becoming LE sows was 10.3% higher for reserviced gilts than for non-returned gilts (P<0.05). Sows with PBA ≤ 7 pigs in parity 1 had 19.4 and 28.5% higher proportions of females becoming LE sows than those with PBA 8-11 and ≥ 12 pigs in parity 1, respectively (P<0.05). In conclusion, in order to reduce the proportion of females becoming LE sows we recommend mating matured gilts at a lower age, reducing the percentage of reserviced gilts and increasing PBA in parity 1.

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The objective of the present study was to compare sow reproductive performance between induced-farrowing (IF) and natural farrowing (NF) sows in ‘Early’ or ‘Late’ farrowing herd groups, based on the proportions of IF records of sows in each herd. Nineteen herds were identified in a pig database to be herds commonly practicing IF, and were used in the present study. The individual records in the 19 herds included 18,792 farrowing records of 9,703 sows during 2008. The 19 herds were categorized into two groups by the proportion of IF records (less than 50%, or 50% or higher) with sow gestation length (GL) 116 days or more:‘Early Farrowing (11 herds)’ and ‘Late Farrowing (8 herds)' herds. Farrowed sows were categorized into two groups:IF or NF sows. Sows in ‘Early Farrowing’ and ‘Late Farrowing’ herds were analyzed separately by parity and GL groups to compare reproductive performance between the IF and NF sows. In the ‘Early Farrowing’ herds, there were no differences in pigs born alive between the IF and NF sows in any parity or GL group. In contrast, in the ‘Late Farrowing’ herds, the IF sows with GL 114 days in parity 6 or higher had 1.5 fewer pigs born alive than the equivalent NF sows (P<0.05). Also, the IF sows with GL 115 days or more in parity 3 or higher had 0.9 or fewer pigs born alive than the equivalent NF sows (P<0.05). There were no differences in pigs born alive between the IF and NF sows in any GL group in the parity 1 or 2 groups. Additionally, there were no differences between the IF and NF sows in either herd groups for adjusted 21-day litter weight, weaning-to-first mating interval or farrowing percentage in any parity or GL group. In order to improve the number of pigs born alive, such sows delayed farrowing should be carefully monitored, and IF should be practiced for these sows with assisted farrowing.

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[in Japanese]

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The objectives of the present study were to compare the occurrence of claw lesions, behavior and reproductive performance of pregnant sows housed on either parallel (PRL) or perpendicular slatted floors (PPD). A farrow-to-finish farm was visited three times in 2008 to observe hind claw lesions and behavior of pregnant sows. Sows were housed in a gestation barn with stalls fitted with either PRL or PPD concrete floor slats. Lesions were scored using a five-point score method (0-4) for each of the six claw areas in each sow's four hind claws and overgrown heel was additionally scored. Assessments of lesion scores included total claw lesion score (TCLS) and the highest claw lesion score (HCLS) for each sow and claw area, respectively. TCLS for each sow was obtained by summing the scores of the six areas of the four claws and TCLS for each claw area was the sum of that area's scores for the four hind claws. The respective HCLS were the highest scores for any claw area, and that for each specific claw area. We also recorded relative frequency (%) of postural behavior and stereotypies by point sampling at 15-minute intervals over a six hour period. Reproductive performance data were collected for each sow on the different slatted floors. Linear mixed-effects models were used for comparisons.
The mean (±SEM) TCLS for the 162 sows was 9.5±0.44, and proportions of sows with HCLS 0, 1, 2, 3 and 4 were 1.2, 39.4, 54.5, 4.3 and 0.6%, respectively. Sows on the PPD floors had higher TCLS for the heel area than those on the PRL floors (P<0.05). No differences were found between the PPD and PRL slats for TCLS for each sow or for any claw area of sows (P>0.10). Sows on the PPD floor had higher proportions of HCLS 1 in wall and heel areas than those on the PRL floor (P < 0.05). However, no differences were found between the PPD and PRL slats for the proportions of sows with HCLS 2 and 3 in any area (P>0.10). There were no differences in behavior or reproductive performance indicators between the PRL and PPD floors (P>0.10). In conclusion, PPD floor slats tended to increase superficial claw lesions, but there was no relationship between floor slat direction and either behavior or reproductive performance in pregnant sows.

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Porcine reproductive and respiratory syndrome (PRRS) is an important viral disease in pigs, causing economic losses worldwide. In 2006, highly pathogenic pig disease, which was characterized by high fever, depression, anorexia, red discoloration of the body, and blue ears associated with high mortality, emerged in China. The atypical PRRS virus was isolated from affected pigs, which was identified a deletion of 30 amino acids in its NSP2. After outbreak in China, this highly pathogenic PRRS spread to Southeast Asia. This paper review the history of highly pathogenic PRRS, the situation of the outbreak of highly pathogenic PRRS in China and Vietnam, the molecular characterization of highly pathogenic PRRS virus, and clinical signs and gross lesions of highly pathogenic PRRS.

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H5N1 subtype of highly pathogenic avian influenza virus (HPAIV) has been giving serious damage to the poultry industry since 2004 in Japan. Worst of all, from the end of November 2010 to March 2011, there were 24 outbreaks of HPAI among chicken farms and during the same period, HPAIV was isolated from the carcasses of 63 wild birds. The role of wild birds in spreading HPAIV has been suspected but controversial. This report reviews recent literatures regarding the epidemic cases of HPAIV in wild birds in Asia and Europe, the experimental infection studies using wild birds, and the satellite tracking studies of wild waterfowl in outbreak area. The epidemic cases showed common characteristic that the epidemics recur in the similar situation, i.e., among the same species, in the same area, at the same time of the year, for a limited period of about two months. These characteristics have been explained with the sensitivity difference among bird species and the behaviors of birds. From this study, it is concluded that the collaborative research from the views of both bird ecologists and virologists is an essential tool to elucidate the ecology of HPAIV.

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After the FMD outbreak in Miyazaki prefecture in 2010, government of Japan amended the Animal Infectious Diseases Control Low in April 2011. In this amendment, compulsory notification of the suspected animal, regulations for animal keepers about preventive measures in farms, penalties for delayed notification were reinforced.

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This article introduces the International Conference on Animal Health Surveillance (ICAHS) held in Lyon, France during 17-20, May 2011. As the science-based decision making is broadly demanded nowadays, nationwide animal health surveillances also need the rational planning and implementation, and verifications afterward based on the science. And epidemiology must play an important role on such occasions. International Symposium on Veterinary Epidemiology & Economics is the primary international meeting for the exchanging the ideas and opinions on veterinary epidemiology, however, due to its massiveness, there had little opportunities for the intensive discussions targeting only the animal health surveillance. Therefore, this ICAHS was organized.
This four day conference had eight sessions with a total of 45 oral and 107 poster presentations by more than 260 participants from all over the world. And present report describes each session introducing some presentations with author's personal impression. Some of presentations and related documents are available on the following URL: http://www.animalhealthsurveillance.org/. In addition, those who interested in the respective papers are recommended to check Épidémiologie et Santé Animale No59-60 as the proceedings.

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