Ministry for Primary Industries  
Standards  
Animal & Animal Products  
Animal Imports Team  
PO Box 2526, Wellington 6140 
animalimports@mpi.govt.nz  
 
Risk Management Proposal  
 
Importation of Pig  Semen  
 
 
 
 
 
 
 
February  2013 
 
 
 
 
  
 
 
  
  
   
  
 
 
Ministry for Primary Industries  
Te Manat ū Ahu Atua 
Pastoral House  
25 The Terrace  
P O Box 2526 
Wellington  
New Zealand  
 
 
 
Telephone: +64 4 894 0100  
Facsimile:   +64 4 894 07 33 
Internet : http://www.mpi.govt.nz  
 
 
Standards Branch  
 
 
RISK MANAGEMENT PROPOSAL  
Importation of Pig Semen 
  
February  2013 
 
 
 
 
 
 
 
 
 
 
Howard Pharo  
Manager Import and Export Animals  
Ministry for Primary Industries  
  
Risk Management Proposal for Pig  Semen  February 2013 i Contents   
 
Purpose  3 
Background  3 
Objective  3 
Viral diseases  4 
Bacterial diseases  4 
Options assessment  5 
African swine fever (ASF) virus  5 
Aujeszky’s disease (AD) virus  6 
Bovine viral diarrhoea (BVD) virus  7 
Blue eye disease virus  5 
Classical swine fever (CSF) virus  8 
Foot and mouth disease (FMD) virus  8 
Japanese encephalitis (JE) virus  9 
Porcine myocarditis virus (Bungowannah virus)  10 
Porcine reproductive and respiratory syndrome (PRRS) virus  11 
Swine vesicular disease (SVD) virus  15 
Brucella suis (B. suis)  17 
Leptospira spp.  18  
Risk Management Proposal for Pig Semen  July 2012 3 
 Purpose  
 
The purpose of this document is to:  
• present the risks associated with pig semen;  
• outline options considered for managing those risks;  
• show how the options have been assessed;  
• provide recommendations for import requirements to be included in the 
import health standard (IHS).   
 
Background  
 
Pig semen is considered a risk commodity, with the potential to harbour exotic viral 
and bacterial diseases that could establish in New Zealand.  
 
In October 2009, MPI issued a draft import risk analysis (IRA) for pig semen from 
Australia, the USA, Canada, the European Union, and Norway for public 
consultation.  After receiving feedback from The New Zealand Pork Industry Board 
and Pig Improvement Company, MPI met with representatives of these stakeholder 
groups in December 2009.  As a consequence of matters raised, the draft IRA was 
revis ed and completed in January 2011.  
In March 2012, the Ministry for Primary Industries (MPI) released a draft import 
health standard (IHS) for the importation of pig semen into New Zealand from all 
countries1
Following stakeholder consultation on the draft IHS for the importation of porcine 
semen into New Zealand in 2012 , the IRA was amended to assess the risks 
associated with porcine semen imported from all countries  (not just Australia, the 
USA, Canada, the E uropean Union or Norway)  so that the final version of the risk 
analysis dated December 2012  also contains chapters assessing the risks 
associated with blue eye disease virus, F oot and mouth disease virus, Nipah virus, 
Teschovirus serotype 1, Venezuelan encephalitis virus, and Vesicular Exanthema 
virus.  .  This was developed from the 2011 draft import r isk analysis (IRA) for pig 
semen from Australia, the USA, Canada, the European Union, and Norway.  The 
2011 draft IRA identified six organisms of potential concern in porcine semen (blue 
eye disease virus, foot and mouth disease virus, Nipah virus, Teschov irus serotype 
1, Venezuelan encephalitis virus, and vesicular exanthema virus) but did not assess 
the risk due to these since Australia, the USA, Canada, the European Union and 
Norway claim freedom from these diseases.  
 
For a detailed analysis of the potential hazards and their risks, refer to Import Risk 
Analysis: Pig Semen ( December 2012), which contains the relevant risk 
assessments and analysis of management options against the identified biosecurity  
risks.  
 
Objective  
 
The objective of the risk management measures proposed for the IHS is to manage, 
to an acceptable level, all biosecurity risks posed by the import of pig semen.  
                                                
1 http://www.biosecurity.govt.nz/biosec/consult/draft -ihs-pigsemic.gen   
Risk Management Proposal for Pig  Semen  February 2013 4                                                                                         
From an initial list of 67 organisms/groups of organisms potentially associated with 
pig semen identified in the IRA , 12 of these 67 organisms have been assessed to 
pose a risk in porcine semen.  Below is the list of these 12 organisms.  
 
Viral diseases  
 
•  Aujeszky’s disease  
• Bovine viral diarrhoea  
• Blue eye disease virus  
• Classical swine fever  
• Foot and mouth disease  
• Japanese encephalitis  
• Porcine myocarditis/Bungowannah virus  
• Porcine reproductive and respiratory syndrome  
• Swine vesicular disease  
 
Bacterial diseases  
• Brucella suis  
• Leptospira spp.  
• Salmonella spp. 
 
 This risk management proposal (RMP) identifies 1 3 organisms that warrant risk 
management measures . Below is the list  of these 13 organisms.  
 
Viral diseases  
• African swine fever  
• Aujeszky’s disease  
• Bovine viral diarrhoea  
• Blue eye disease virus  
• Classical swine fever  
• Foot and mouth disease  
• Japanese encephalitis  
• Porcine myocarditis/Bungowannah virus  
• Porcine reproductive and respiratory syndrome  
• Swine vesicular disease  
• Transmissible Gastroenteritis  
 
Bacterial diseases  
• Brucella suis  
• Leptospira spp.  
 
 
The list in the RMP  differs from the 12 organisms identified in the IRA.  
African Swine fever (ASF) and Transmissible Gastroenteri tis (TGE) are included in 
this r isk management proposal and are excluded from the import r isk analysis.  
 
The import risk a nalysis for pig semen concluded African Swine Fever (ASF) and 
Transmissible Gastroenteritis (TGE) not to be risks in porci ne semen . In contrast the 
OIE Code has recommended measures for the importation of semen for both of 
these diseases.     
Risk Management Proposal for Pig  Semen  February 2013 5 MPI has  included measures for ASF and TGE in the draft standar d and will align with 
the Code measures for both ASF & TGE at this stage.  
MPI will seek to influence the OIE to reassess the risk basis for these two diseases.  
 
The final version of the risk analysis (December 2012)  also contains chapters 
assessing the risks associated with B lue eye disease virus, F oot and mouth disease 
virus, Nipah virus, Teschovirus serotype 1, Venezuelan encephalitis virus, and 
Vesicular Exanthema virus.  Out of these s ix diseases only  Foot and Mouth disease  
and B lue eye disease were concluded to be hazards in porcine semen.  
 
Salmonella is excluded from the risk m anagement proposal and included in the 
import  risk analysis.  
Salmonella  spp. have  been recognised in the IRA  as a potential hazard in pig 
semen. However, any requirements for managing the risk of transmission of Salmonella  spp. were removed in line with New Zealand’s  IHS for bovine semen.  
 
 
African swine fever (ASF) virus  
 
• 
Semen originating from donor boars that have lived their entire lives in countries 
or zones free from ASF  (in accordance with the requirements o f the OIE Code)  
could be imported without further sanitary measures.  Option 1  
 
• 
Semen originating from collection centres certified as compliant with OIE Code 
Chapters 4.5 and 4.6 could be considered suitable for importation.  Option 2  
 
Options assessment and considerations  
 The import risk analysis for pig semen identified that African Swine Fever (ASF) was 
a preliminary hazard. After further risk assessment it was concluded not to be a 
hazard requiring any risk mitigation measures.  
 
In contrast the OIE Code has recommended measures for the importation of semen 
for ASF.   
Chapters 4.5 and 4.6 of the OIE Code are the current internationally recognised 
standards for managing the risk of ASF in pig semen.  
Chapter 4.6 of the OIE Code contains requirements for ASF f or boars resident in 
semen collection centres.  
Given the existence of international standards for ASF -free ( Article 15.1.8  of the OIE 
code ) and ASF -infected countries ( Article 15.1.9  of the OIE code ) the most 
appropriate measures for risk management here would be to accept these Code 
articles for importation of pig semen.  
 
MPI will seek to influence the OIE to reassess the risk basis of ASF  but in the 
interests of expedience, at this point in time measures that are in line with the OIE 
code for ASF will re main in the IHS  
 
 
Requirements recommended for the I HS 
 
Both options described above are considered to effectively manage the risk of ASF 
in imported pig semen.   
Risk Management Proposal for Pig  Semen  February 2013 6  
 
Aujeszky’s disease (AD) virus  
 
• 
Aliquots of each batch of semen to be imported could be tested by a MPI 
approved PCR test for the presence of virus. Importation of semen giving positive 
results could be prohibited.  Option 1  
 
 
• 
Semen originating from collection centres certified as complia nt with OIE Code 
Chapters 4.5 and 4.6 could be considered suitable for importation.  Option 2  
 
• 
Semen for export to New Zealand could come from donor boars that were kept in 
an establishment or semen collection centre located in an AD -free country or 
zone (in accordance with the requirements of the OIE Code)  at the time of semen 
collection.  Option 3   
 
 
Options assessment and considerations  
PCR tests provide a rapid and highly sensitive method for detecting AD virus in pig 
semen , however the option for PCR testing alone was s ubsequently removed from 
the IHS due to a stakeholder submission. The explanation and the MPI response  for 
not having this option as a measure in the IHS is in point 2.4 in the review of 
submissions  
                                                                                                                                                                                                                                                                                                                    
Chapter  4.6 of the OIE Code contains requirements for AD for boars resident in 
semen collection centres. Chapters 4.5 and 4.6 of the OIE Code are the current 
internationally recognised standard for managi ng the risk of AD in pig semen.  
Given the existence of international standards for AD -free (8.2.13) and AD -infected 
countries (8.2.15) the most appropriate measures for risk management here would be to accept these Code articles for importation of pig seme n.  
 
 
 Requirements recommended for the I HS 
Options 2 and 3  are considered to effectively manage the risk of Aujeszky’s disease 
(AD) virus in imported semen.  
 
 
Blue eye disease virus 
 
• 
 Option 1  
Semen for export to New Zealand could come from donor boars that were kept in an 
establishment or artificial insemination centre located in a country or zone 
recognised by MPI as Blue eye disease ( PoRV ) free at the time of semen collection.  
 
• 
 Option 2   
Risk Management Proposal for Pig  Semen  February 2013 7 Donor boars are to be subject to MPI approved serological testing with negative 
results.  
 
 
Options assessment and considerations  
The final version of the risk analysis (December 2012)  was amended so that it 
includes  chapters assessing the risks associated with blue eye disease virus, F oot 
and mouth disease virus, Nipah virus, Teschovirus serotype 1, Venezuelan 
encephalitis virus, and Vesicular Exanthema virus. Blue eye disease was concluded 
to pose risk in porcine se men.  
Blue eye disease also known as  La-Piedad Michoacan paramyxovirus disease  or 
Porcine rubulavirus (PoRV ) has  only been described in Mexico so sanitary measures 
are not required for imports of porcine semen originating from pigs in any country 
other than Mexico.  
 
Requirements recommended for the IHS  
Both option 1 and option 2 are considered to effectively manage the risk  
 
 
Bovine viral diarrhoea (BVD) virus- 2 
 
• 
Donor boars could have lived their entire lives in countries that are free from 
BVD-2. Option 1  
 
• 
Donor boars could be required to be tested for antibody to BVD -2 virus by a MPI 
approved test at least 21 days after collection of the semen batch for export, with 
negative results.  Option 2  
 
 
 
Options assessment and considerations  
Classical Swine  Fever (CSF) virus and Bovine Viral Diarrhoea (BVD) virus have 
been listed as two separate diseases in this RMP as opposed to the integrated 
approach in the IRA.  
 
Some stakeholders raised concerns during targeted consultation in 2011 that there 
should be n o testing for BVD -2 virus as it is not a listed disease of pigs in the OIE 
Code.  
 
However, N ew Zealand is free of BVD -2 (Horner 2000; Vilcek et al 1998; OIE 
2008b). Investigations of suspected BVD -2 in cattle have not detected any BVD -2 in 
the ruminants in New Zealand. The only isolates of BVD -2 recorded in New Zealand 
were from two commercial serum samples of overseas origin in 1997 . 
 
As the IRA states, field infection to boars can occur and result in persistent testicular 
infections with BVD -2, and transmission via semen to N ew Zealand pigs could occur. 
Whilst  the consequences are likely to be low to the N ew Zealand pig population, the 
consequences of any infection to the New Zealand cattle industry c ould be high.  
  
Risk Management Proposal for Pig  Semen  February 2013 8 Measures to prevent transmission of BVD -2 virus are already in place for importation 
of bovine semen. Risk management measures for BVD -2 virus in pig semen are 
therefore justified.  
 
Requiremen ts recommended for the I HS 
Both options described above are considered to effectively manage the risk of BVD -2 
virus in imported semen.  
 
 
 
Classical swine fever (CSF) virus  
 
• 
Donor boars could have lived their entire lives in countries that are free from CSF 
(in accordance with the requirements of the OIE Code) . Option 1  
 
• 
Semen originating from collection centres certified as compliant with OIE Code Chapters 4.5 and 4.6 could be considered suitable for importation . Option 2  
 
• 
Every batch of semen to be imported could be tested by a MPI approved reverse 
transcriptase (RT) PCR test. A positive test on any batch of semen could result in 
disqualification of that semen.  Option 3  
 
 
Options assessment and considerations  
Chapter 4.6 of the OIE Code contains requirements for CSF for boars resident in 
semen collection centres. Chapters 4.5 and 4.6 of the OIE Code are the current 
internationally recognised standard for managing the risk of CSF in pig semen.  
 
 
 
Requirements recommended for the I HS 
Options 1 and 2 are considered to effectively manage the risk of Classical Swine 
fever (CSF) in imported  pig semen.  
Given the ex istence of international standards for CSF -free (8.2.13) and CSF -
infected countries (8.2.15) the most appropriate measures for risk management here 
would be to accept these Code articles for importation of pig semen.  
 
The option for PCR testing alone was removed from the IHS due to a stakeholder 
submission . The MPI response to this submission is point 2.5 in the R eview of 
submissions.  
 
Foot and mouth disease (FMD) virus   
 
• 
Donors were resident for at least the 3 months before semen collection in a country or zone that is free from FMD without vaccination (in accordance with the 
OIE Code).  Option 1  
  
Risk Management Proposal for Pig  Semen  February 2013 9 • 
a. The herds of origin, semen collection centre, donor animals and semen for 
export must comply with OIE Code recommendations for export of pig semen 
from countries or zones presenting a risk of FMD.  Option 2  
 
AND  
 
b. Each semen collection, processing and storage facility in the exporting 
country intended to be used during the preparation of an export consignment 
to New Zealand must be approved by MPI . The approval will be depende nt 
on the facility, its location and operating standards, and that the verification 
systems of the veterinary authority achieve a very high level of risk 
management for FMD. The process for MPI approval may include site 
inspection. MPI reserves the right to supervise collection, require the use of 
New Zealand approved semen collection personnel, or require any other 
measures deemed necessary to ensure compliance with facility and operating standards upon which the approval is based.  
 
 
 
Options assessment and considerations  
 
 
Chapter  4.6 of the OIE Code contains requirement s for FMD  for boars resident in 
semen collection centres. Chapters 4.5 and 4.6 of the OIE Code are  the current 
internationally recognised standard for man aging the risk  of FMD  in pig semen.  
 
Because of the extreme seriousness of the disease and the catastrophic 
consequences that would result from its introduction, it was concluded that 
importation of pig semen should be limited to countries or zones that are free of FMD 
virus in accordance with the OIE Code, or countries or zones in which compliance 
with measures in accordance with the recommendations of the OIE Code for import 
of semen  from FMD infected countries or zones has been reviewed and accepted by 
MPI. 
 
Requireme nts recommended for the I HS 
Both options described above are considered to effectively manage the risk of FMD 
in imported pig semen.  
 
 
Japanese encephalitis (JE) virus 
 
• 
Semen donors could be tested for presence of antibody by a MPI approved test 
at the time of collection and again 30 days after collection of semen. Importation 
of semen from donors that were positive at the time of collection could be 
permitted on the basis that seropositive animals are not viraemic. Semen from 
boars that were nega tive at the time of collection and negative 30 days later 
could be permitted while semen from donors that were negative at collection and positive 30 days later could be prohibited on the basis that they may have been 
viraemic at the time of semen collecti on. Option 1  
 
• 
Importation could be restricted to semen collected from donors resident in regions  that are free from JE virus . Option 2   
Risk Management Proposal for Pig  Semen  February 2013 10  
 
Options assessment and considerations  
Option 2 is considered to be the most appropriate measure to manage the risk of JE 
virus in imported semen. T he OIE Code does not include recommendations for 
managing the risk of JE virus in semen of any species. JE occurs very rarely in some 
parts of Northern Australia and t hose regions of Australia considered to be at risk 
from JE virus infe ction are likely to be remote from commercial pigs.  
 Due to a stakeholder submission, the term “region” has been replaced with “zones”. 
The MPI response to this submission is contained in 3.7 of the Review of 
Submissions  
 
 
Requirements recommended for the  IHS 
Option 2 is considered to effectively manage  the risk of JE in imported porcine  
semen.  
 
 
Porcine myocarditis virus (Bungowannah virus)  
 
• 
Pig semen could be imported from countries that are free from porcine 
myocarditis virus without sanitary measures.  Option 1  
 
• 
Semen originating from Australian semen collection centres which can be certified as not including individuals from properties where porcine myocarditis 
has been identified could be imported without any further sanitary measures.  Option 2  
 
• 
Donor boars originating from properties where porcine myocarditis has been 
recognised should be isolated and tested to demonstrate they are seropositive  
for porcine myocarditis virus, but  negative for porcine myocarditis virus RNA 
before enter ing the semen collection centre  Optio n 3 
 
  
 
Options assessment and considerations  
Porcine myocarditis is confined to a single enterprise composed of a number of small 
properties in New South Wales, Australia. There have been no other reports of the 
disease outside this e nterprise. This enterprise includes an artificial insemination 
facility which uses boars from the positive site after testing with a protocol to ensure they are antibody positive and antigen negative for porcine myocarditis virus.  Since 
this enterprise was placed under quarantine in 2003, approximately 275,000 semen 
doses have been used to inseminate 50,000 sows annually in both the positive site 
and in negative farms with no further spread of this disease.  Considering there has 
been no further spread of the virus, it was  reasonable to conclude that these current 
measures are effectively managing the risk of spread in pig semen.  
 A peroxidise- linked assay to detect antibodies to porcine myocarditis virus and an 
RT-PCR test to detect porcine myocarditis vir us RNA have been described.  
 Public consultation resulted in further consideration of the proposed measures.   
  
Risk Management Proposal for Pig  Semen  February 2013 11 The  draft IRA states: “Although the disease occurs extremely rarely and there is no 
evidence suggesting that long- term carriers of virus occur, given that the 
Bungowannah virus has been identified as a Pestivirus, it is assumed that there is a 
non-negligible likelihood of tran smission in semen (see Chapter 10)”.  
A recent publication (Finlaison et al. 2012. Experimental Bungowannah virus infections in weaner pigs and pregnant sows – virology and serology studies. 
Proceedings 22
nd International Pig Veterinary Society Congress 2012) shows long 
term carriage is more likely than assumed in the draft IRA. Furthermore, it illustrates that PMV can be considered very similar in behaviour to other pestiviruses (eg. BVD, 
CSF). Taking this new scientific information into a ccount, a more cautious approach 
is justified.  
 MPI recognises  that there has been limited surveillance to demonstrate freedom 
from Bungowannah virus in properties not linked to the infected enterprise.   
Furthermore, the failure to eradicate this disease and the reported disease 
breakdown on a site where eradication had been previously achieved indicate 
ongoing biosecurity lapses. MPI also notes that animals from the infected enterprise 
in New South Wales are sent to Victoria for growing out and slaughter w ith no 
restrictions being placed on these Victorian properties.  
Reflecting these concerns, Option 2 is considered not to effectively manage the risk 
of introducing porcine myocarditis virus in imported pig semen, and adding an 
additional testing option to option 3 is recommended.  
 
Option 3 will now read:  
 
Donor boars originating from properties where porcine myocarditis has been 
recognised should be isolated and tested with an MPI approved test  to 
demonstrate they are seropositive for porcine myocarditis virus, but  negative for 
porcine myocarditis virus RNA before enter ing the semen collection centre  
 AND 
 
Every batch of semen to be imported was tested  by a MPI approved RT-PCR 
test, with negative results.  
 
Please refer to 2.6, 3.8 , 6.2 and 7.1 in the review of submissions for further 
discussion.  
 
Requirements recommended for the I HS 
Either options 1 or  3 are considered to effectively manage the risk of introducing 
porcine myocarditis virus in imported pig semen.  
 
 
Porcine reproductive and respiratory syndrome (PRRS) virus  
 
• 
Pig semen could be imported from countries that are recognised as free from PRRS without sanitary measures.  Option 1  
 
• 
The semen collection centre has remained free of PRRS for the collection peri od 
and 21 days after the end of the collection period by the following ways:  Option 2  
 
a. Boars were sourced from donor herds that do not vaccinate against PRRS,   
Risk Management Proposal for Pig  Semen  February 2013 12 and were  shown to be negative for PRRS before entering the semen 
collection centre as described in Chapter 4.6 of the OIE Code  
 
AND 
 
b. At the start of the collection period and no less than 30 days subsequently,  
donor boars were tested for PRRS virus by serum PCR, with negative results  
 AND 
 
c. 21 to 50 days after the final sample collection, donor boars wer e tested by a  
multivalent serum ELISA for PRRS antibodies  that uses both European and 
American strain antigens, with negative results.  
 
• 
a. Boars should be sourced from donor herds that do not vaccinate against PRRS, and be shown to be negative for PRRS before entering the semen 
collection centre as described in Chapter  4.6 of the OIE Code  Option 3  
 
AND 
 
b. Individual donor boars should be tested by serum PCR each day of collection 
with negative results.  
 
AND 
 
c. During each day of the collection period, boars in the semen collection centre 
should be tested for PRRS virus by serum PCR, with the number of boars 
sampled sufficient to give a 95% confidence of detecting a 5% prevalence 
rate 
 
AND 
 d. 30 to 50 d ays after the final sample collection, boars in the semen collection 
centre should be tested by a multivalent serum ELISA for PRRS antibodies  
that uses both European and American strain antigens , with the number of 
boars sampled sufficient to give a 95% co nfidence of detecting a 5% 
prevalence rate.  
 
• 
a. Boars should be sourced from donor herds that do not vaccinate against 
PRRS, and be shown to be negative for PRRS before entering the stud as 
described in Chapter  4.6 of the OIE Code  Option 4  
 
AND  
b. Individual donor boars should be tested for PRRS virus by serum PCR each 
day of collection with negative results.  
 
AND 
 
c. During each day of the collection period, boars in the semen collection centre 
should be tested for PRRS virus by serum PCR, with the number of boars 
sampled sufficient to give a 95% confidence of detecting a 5% prevalence 
rate 
 
AND  
Risk Management Proposal for Pig  Semen  February 2013 13  
d. 30 to 50  days after the final sample collection, boars in the semen collection 
centre should be tested by a multivalent serum ELISA for PRRS  antibodies  
that u ses both European and American strain antigens , with the number of 
boars sampled sufficient to give a 95% confidence of detecting a 5% 
prevalence rate.  
 
AND 
 e. Semen should be accompanied by certification that during the three months 
since the last collection date there has been no clinical or serological 
evidence of PRRS in the donor herds or the semen collection centre itself.  
 
• 
a. The semen collection centre could be required to have a documented 
absence from PRRS. All pigs entering the semen collection centre must 
originate from herds which have never recorded a clinical case of PRRS.  Option 5  
 
AND 
 
b. The semen collection centre could be required to have never used a modified 
live PRRS virus vaccine nor introduced pigs from herds that have used a 
modifi ed live PRRS virus vaccine  
 
AND 
 c. All pigs in the semen collection centre could be required to have completed a 
5 week period of isolation.  While undergoing this 5 week isolation period the 
pigs must be exposed throughout the isolation period to direct con tact with at 
least an equal number of sentinel grower pigs and the total number of pigs in 
the semen collection centre undergoing isolation could be required to be at 
least ten at all times  
 
AND 
 
d. The sentinel grower pigs used could be required to be betwee n 12 and 24 
weeks of age and derived from 3 or more herds which have been shown by 
an approved multivalent ELISA to be free of PRRS within two months prior to 
the commencement of the isolation period  
 
AND 
 
e. During the isolation period, all pigs undergoing i solation could be tested for 
PRRS using an approved multivalent ELISA test, on two occasions at the 
start and finish of the isolation period, with a negative result in each case.  
 
AND 
 f. Semen collected from donor boars during the 5 week period of isolation 
(either during approval of the semen collection centre or prior to entry of a 
donor boar onto an approved semen collection centre) could become eligible 
for export to New Zealand upon s uccessful completion of isolation (i.e. no 
positive test for PRRS in any donor boar or sentinel simultaneously 
undergoing isolation).  
  
Risk Management Proposal for Pig  Semen  February 2013 14 • 
Reflecting that breakdowns in semen collection centres still occur despite 
intensive monitoring, the importatio n of pig semen from countries with PRRS 
could be prohibited.  Option 6  
 
Options assessment and considerations  
 
Chapter  4.6 of the OIE Code contains requirements for PRRS for boars resident in 
semen collection centres.  Chapters 4.5 and 4.6 of the Code provide some 
assurance that infected boars are not introduced into a semen collection centre, 
although ensuring a centre remains free of infection is recognised to be challenging. 
Additional requirements over and above the measures of the OIE C ode are therefore 
suggest ed to meet New Zealand’s appropriate level of protection for PRRS in pig 
semen.  
 
Option 2 was added to this cha pter after MPI received feedback during targeted 
consultation (2011). This option balances different views in regards to compliance to 
the OIE Co de, frequency and interval of testing of the donor boars while in the 
semen collection centre and consideration of possible seroconversion post 
collection.  
 
This option initially stated:  
 
“The semen collection centre has remained free of PRRS for the collection period 
and 21 days after the end of the collection period by the following ways:  
 
a. Boars were sourced from donor herds that do not vaccinate against PRRS,  
and were  shown to be negative for PRRS before entering the semen 
collection centre as described in Chapter 4.6 of the OIE Code”  
 
Due to a stakeholder submission this additional option 2 was amended so that it now 
states:  
 
The semen collection centre has remained f ree of PRRS for the collection period 
and 21 days after the end of the collection period by the following ways:  
 
a. Boars were sourced from donor herds that do not vaccinate against PRRS,  
and were  shown to be negative for PRRS before entering the semen 
collection centre as described in Chapter 4.6 of the OIE Code  
  
Generally, it was perceived that daily testing of the entire semen collection centre 
population during collection was impractical and was aiming for an unnecess arily 
high level of protection (Option 3 and 4).  
 
Stakeholders have stated in their submissions on the draft import risk analysis from 
2009 that very few semen collection centres or the isolation units supplying a semen 
collection centre are designed to handle sentinel pigs, so would be  unable and 
unwilling to accommodate Option 5 in any way without compromising their own 
biosecurity or animal welfare. Also, semen collection centres are mostly sourced from a single breeding herd or at least a few herds with a similar health status.   
Customers of a semen collection centre (including importers within the New Zealand 
industry) would not be willing to add to the risk of disease introduction by agreeing to 
further sources of pigs coming into proximity with donor boars, especially from 
complet ely separate sources. Improvements in the understanding of PRRS 
monitoring in semen collection centres, the recognition of serum testing as being  
Risk Management Proposal for Pig  Semen  February 2013 15 more sensitive than semen testing to detect PRRS, and the wide availability of 
molecular diagnostic techniques  now mean that the risk of introducing PRRS virus in 
imported semen can now be effectively managed without the use of sentinel pigs in 
semen collection centres (Option 5).  
 Stakeholders have also indicated in their 2009 submissions that they believe it would 
be desirable to require semen to be held for a period of three months after collection 
and only released if accompanied by certification that during the three months since 
the last collection date there has been no clinical or serological evidence of  PRRS in 
the donor herd.  Option 2 requires semen to be held for at least 21 days ( due to 
possible seroconversion occurring 14 to 21 days post infection)  before the donor 
serology is undertaken to demonstrate freedom from PRRS. Further requirements to 
demonstrate freedom from exposure beyond this and in the donor herd  are 
considered unnecessarily trade restrictive.  
 
Option 6  would limit pig semen imports to countries that are free of PRRS.  
 
Background  
 
Of all the OIE -listed porcine diseases that are considered to be a risk in semen, 
PRRS is unique in that no  OIE Code chapter has been written to outline standards 
for sanitary measures to manage the risk of international transmission of this disease.   New Zealand has traditionally taken a very cautious position regarding the 
requirements for managing the risk of PRRS  virus.  
 
Historically PCR testing of semen has been used in donor boars to monitor for 
PRRS.  However, serum PCR (using either a TaqMan PCR tes t or a nested PCR 
test) is more sensitive than semen PCR for PRRS virus detection during the first six 
days following infection and boars can be detected as PRRS -positive by serum PCR 
before semen PCR.  Serum is currently considered to be the preferred sam ple to use 
as PRRS virus is present in much higher levels in serum than in semen and is 
detectable at least 1- 2 days sooner.  PCR testing of pooled serum samples has been 
shown to be as effective as testing individual samples for detection of PRRS virus in 
donor boars.  Due to viral mutation, some strains of PRRS virus may be undetected 
by PCR testing,  so post collection  testing of boars by serum ELISA is also 
recommended.  
 
Requirements recommended for the I HS 
Either options 1 or  2 are considered to effectively manage the risk of introducing 
PRRS virus in imported pig semen.  
 Please refer to 1.6, 2.7, 3.9 of the R eview of S ubmissions  for further discussion.  
 
 
Swine vesicular disease (SVD) virus  
 
• 
Semen originating from donor boars that have lived their entire lives in countries 
free from SVD (in accordance with the requirements of the OIE Code)  could be 
imported without further sanitary measures.  Option 1  
 
• 
Semen originating from donor boars from co untries considered infected with SVD 
could be required to comply with the recommendations contained in 15.4.10 of 
the OIE Code, including compliance with Chapters 4.5 and 4.6 of the Code.  Option 2  
  
Risk Management Proposal for Pig  Semen  February 2013 16 • 
Every batch of semen to be imported could be tested by a MPI approved PCR. A 
positive test on any batch of semen could result in disqualification of that semen.  Option 3  
  
Options assessment and considerations  
Historically, virus isolation has been considered an insensitive test for pig semen due 
to the toxicity of semen to  tissue culture. However, the development of molecular 
techniques provides a rapid and highly sensitive test for the detection of SVD virus i n 
pig semen.  The option for PCR testing alone was removed from the IHS due to a 
stakeholder submission. The MPI response to this submission is point 2.8 in the 
review of submissions.  
Options 1 and 2 only are considered to effectively manage the risk of Swi ne vesicular 
disease (SVD) in imported pig semen.  
Chapter 4.6 of the OIE Code contain requirements for SVD for boars resident in 
semen collection centres . Chapters 4.5 and 4.6 of the OIE Code are  the current 
internationally recognised standard for managing the risk of SVD virus in pig semen.  
Given the existence of international standards for SVD free ( 15.4.9) and SVD -
infected countries (15.4.10) the most appropriate measures for risk management 
here would be to accept these Code articles for importation of pig semen.  
  
Requirements recommended for the I HS 
Option  1 and 2 only are considered to effectively manage the risk of Swine vesicular 
disease (SVD) in imported pig semen.  
 
 
Transmissible Gastroenteritis (TGE) 
 
Option 1  
Semen originates from donor boars that have been resident since birth in a country 
in which TGE is officially notifiable and no clinical case has been recorded in the 
previous three years  
  AND  
the semen was collected, processed and stored in conformity with the provisions of 
Chapters  4.5. and 4.6.  
 
Option 2  
The donor boars showed no clinical sign of TGE on the day of collection of the 
semen;  
AND  
the donor boars  have been resident for at least 40  days on a semen collec tion 
centre, and all the pigs on this semen collection centre were free from clinical signs of 
TGE during the 12 months prior to collection;  
AND  
Risk Management Proposal for Pig  Semen  February 2013 17 for frozen semen, the donor boars were subjected to a diagnostic test 
for TGE with negative results at least 14 days after collection;  
AND 
The semen was collected, processed and stored in conformity with the provisions of 
Chapters  4.5 and 4.6.  
Options assessment and considerations  
The import risk analysis for pi g semen identified that Transmissible gastroenteritis 
(TGE) was a preliminary hazard. After further risk assessment it was concluded not 
to be a hazard requiring any risk mitigation measures.  
In contrast the OIE Code has recommended measures for the importation of semen 
for TGE .  
 Chapters 4.5 and 4.6 of the OIE Cod e are the current internationally recognised 
standards for managing the risk of TGE  in pig semen.  
Chapter 4.6 of the OIE Co de contains requirements for TGE  for boars resident in 
semen collection centres.  
 
Given the existence of international standards for recommendations for the 
importation of porcine semen with regard to TGE  (Article 15.5.4 of the OIE code ) the 
most appropriate measures for risk management here would be to accept these Code articles for i mportation of pig semen.  
 
MPI will seek to influence the OIE t o reassess the risk basis of TGE  but in the 
interests of expedience, at this point in time measures that are i n line with the OIE 
code for TGE  will remain in the IHS  
 Please also see point 3. 11 in the review of submissions.  
 
Requirements recommended for the IHS  
Either option 1 or 2   are considered to effe ctively manage the risk of Transmissible 
Gastroenteritis (TGE) in imported pig semen.  
 
 
 
 
Brucella suis (B. suis)  
 
• 
Pig semen could be imported from countries that are free from B. suis  without 
sanitary measures.  Option 1  
 
• 
The requirements of Article 15.3.5 (including compliance with Chapters 4.5 and 
4.6) would ensure that imported semen was free from B. suis . Option 2  
 
Options assessment and considerations  
Chapter 4.6 of the OIE Code contains requirements for B. suis  for boars resident in 
semen collection centres. Chapters 4.5 and 4.6 of the OIE Code are  the current 
internationally recognised standard for managing the risk of B. suis  in pig semen.   
 
Requirements recommended for the I HS  
Risk Management Proposal for Pig  Semen  February 2013 18 Either option 1 or option 2 are considered to effectively manage the risk of 
introducing B. suis  in imported pig semen.  
 
 
Leptospira spp.  
 
• 
The disease could be considered to be of negligible risk to human or animal health, 
and trade without restrictions could be permitted.  Option 1  
 
• 
Donor boars could be tested serologically with a variety of antigens that occur in t he 
exporting country and not in New Zealand, with negative results.  Option 2  
 
• 
Donor boars could be treated with effective antibiotics within one week of semen 
collection.  Streptomycin is the antibiotic of choice although it may not be available in 
all cou ntries.  Option 3  
 
• 
Semen diluents containing antibiotics that are effective against Leptospira spp. could 
be used in the preparation of the semen.  Option 4  
 
Options assessment and considerations  
Because of the occurrence of long- term carriers of infection, quarantine is not a 
suitable option.  
 
Diagnosis in donor boars by means of serology is complex to perform and the results 
are difficult to interpret because of the many serovars and the difficulty in interpreting 
cross reactions and low -titre reactions.  
 
Testing of semen samples by culture or PCR is problematic because isolation of 
organisms is difficult and selection of primers for PCR that will recognise all serovars 
has not yet be en achieved.  
 
Leptospira are sensitive to a variety of antibiotics, and treatment of animals or 
inclusion of antibiotics in prepared semen has traditionally been used to prevent 
dissemination of Leptospira spp. by international trade.  
 The limited availab ility of streptomycin in a number of countries limits the usefulness 
of option 3.  
 
The recent IHS for bovine semen considered the use of antibiotics in semen diluents 
to be sufficient to manage the risk of Leptospires in semen.  Consistent with this positi on, option 4 would be the most appropriate measure for pig semen.  
 
Requirements recommended for the I HS 
Option 4 is considered to effectively manage the risk of introducing exotic  Leptospira 
spp. in imported pig semen.  
 
 
 
   
Risk Management Proposal for Pig  Semen  February 2013 19