**2. Main risky points during Artificial Insemination (AI)**

IA is a commercially widespread technique worldwide. Therefore, the procedure for collec‐ tion and manipulation of the semen besides the AI itself must be carefully accomplished in order to ensure that AI will not represent a risky factor for transmission of infectious diseas‐ es. Although there are wide variety of diseases that could contaminate the semen and conse‐ quently the inseminated female, the significance of a particular disease will vary according to epidemiological parameters and geographical localization of the farm. Even the risk for disease transmission is not the same in different countries of the world. Hence, the concept of pathogen-free centrals has become a common cause, since it is possible to obtain the pathogen-free semen either in countries that are free and in those that are not free from cer‐ tain disease, according to definition by World Organization for Animal Health (OIE).

ment of this biotechnology was not accompanied by scientific knowledge related to the transmission of diseases. On one hand, the use of the artificial insemination has the great ad‐ vantage in optimizing the use of the boar, whereas reducing the number of animals in the farm and consequently the costs of the management, medicines and animal acquisitions, the AI may function as a means diffusing pathogens, since there is no ideal sanitary control dur‐ ing the collection and manipulation of the semen. In this case, the AI using contaminated semen just maximizing spread of certain virus and bacteria since a single boar ejaculate can

In this context, a considerable concern is assumed in relation to hygienic procedures in the semen manipulation process, especially in relation to semen destined for international mar‐ ket [3]. This fact is justified by the evidence of the possibility for transmission of some dis‐ eases via semen of swine. Among the possible agents that can transmit diseases are Aujeszky's disease virus, *classical swine fever virus* (CSFV), *african swine fever virus*, *porcine cir‐ covirus 2* (PCV2), *porcine reproductive and respiratory syndrome virus* (PRRSV), *porcine parvovi‐ rus* (PPV), *Chlamydia* sp., *Leptospira* sp, *Mycobacterium tuberculosis*, *Mycobacterium*

The effect from contamination of the boar´s semen may represent a considerable economical loss to the producer. This occurs because the presence of the bacterial or viral agents in the semen leads to the loss of fertility and reduction of the semen quality in male, and embryon‐ ic/fetal death, endometritis and systemic infection in the inseminated females, thereby con‐

Although the routine addition of antibiotics (ATB) in the seminal diluents may even elimi‐ nate a high number of contaminant bacteria, most viral agents still remain alive. Therefore, a concern has been assumed in relation to those pathogenic agents. Despite the availability of studies concerning to antivirus, these ones are still not used commercially due to ineffective‐ ness of the action, especially related to high toxicity to sperm cells. Thus, the main control criteria AI are limited to veterinary communication, inspection by health agencies and con‐ trol strategies such as vaccination, isolation and monitoring of animals [5]. Moreover, effi‐ cient routine tests for identification of contaminants in the semen samples still remain as a

Thus, this chapter aims to clarify some points referring to the potential for contamination by infectious agents during AI procedure in pigs, as well as to identify the main agents likely to be transmitted by this biotech, which can contribute to reduced fertility of the animals, be‐ sides the possible control measures that should be performed in order to reduce the dissemi‐

IA is a commercially widespread technique worldwide. Therefore, the procedure for collec‐ tion and manipulation of the semen besides the AI itself must be carefully accomplished in

be used for insemination of various sows.

118 Success in Artificial Insemination - Quality of Semen and Diagnostics Employed

*paratuberculosis* and *Brucella abortus* [4].

tributing to reduction in the size of the litters.

reality that is very far from the existent commercial farms.

**2. Main risky points during Artificial Insemination (AI)**

nation and effect of those pathogens on animals.

Guérin and Pozzi, (2005) [6] suggested that diseases able to cause negative impact on AI can be evaluated according to health risk as follows: a) Diseases that were eradicated within a country or continent, such as the Classical Swine Fever in Brazil; b) diseases to which there is already an integrated program for control in AI, such as the CSFV or Aujeszky's disease, which implies a negative state of the donor boars; c) diseases that are considered as likely to be transmitted by AI, such as diseases associated with PCV2, PPV and transmissible gastro‐ enteritis, which are neither controlled nor associated with prophylactic measures routinely adopted.

The seminal contamination may be classified as extrinsic or intrinsic. The first case occurs when contamination occurs through an external source, such as feces or contaminated mate‐ rials used during semen collection or processing. The intrinsic contamination occurs due to viral infection that can be systemic or local, as occasioning viral elimination through testi‐ cles, accessory or preputial glands [6]. Thus, it can be indicated that the main risk points for contamination of the semen can occur at the semen collection stages, in semen manipulation, or in artificial insemination procedure according to sanitary conditions of the farm.

Before the semen collection procedure, all utensils to be used and specially the material in contact with the semen must be sterilized according to routine hygienic procedures and equipments available at each AI station. The use of dry heat (ovens), moist heat (autoclave) and radiation (ultraviolet) are most suitable for sterilization. These materials include the col‐ lecting funnel and the collecting glass where the semen will be stored until the moment of dilution. Because accidents may occur during the collection procedure, it is advisable to build up a stock of sterile materials ready to be used in the case of contamination during the procedure.

The animal' prepuce is usually contaminated by a wide variety of infectious agents, as re‐ ported by some authors [7,8,11]. Thus, the occurrence of agents such as *Corynebacterium suis*, *Arcobacter spp.* and the Aujeszky's disease virus (ADV) in the ejaculate of the infected ani‐ mals becomes a real possibility to be considered. Therefore, the examination of the semendonor animals prior to collection of the semen is essential in order to ensure the sanitary quality of the semen. However, this previous evaluation may be not completely effective. This is due to the fact that certain viral agents, such as ADV which causes the Aujeszky's disease, have the peculiar ability to establish latency in the reproductive organs, therefore causing contamination of the semen although the animals remain serologically negative for those diseases [9]. Other viral agents such as PCV2 and PRRSV have a determinated sero‐ conversion period over which the agent will be eliminated through semen. Even when the animal is serum-negative for the infection [10], this elimination may still occur under contin‐ uous or intermittent way during the months after infection [12]. Another measure that can be taken in order to reduce contamination is the elimination of the first ejaculatory jets, that are characterized by high microbial contamination, therefore obtaining a better quality of the semen. The environmental contamination is also a factor to be considered during the col‐ lection procedure. Thus, the sanitary procedure of either male' preputial region and the dummy sow used for collection are routine procedures to avoid an eventual contamination of the semen outside the animal' body.

the same one. Thus, the complexity of the conditions required for establishment of this process

**Table 1.** Presence of the viral agents in semen of pigs and the risk for their transmission through AI (Adapted from [14] and [6]. ND: No data; CSFV:*classical swine fever virus*; FMD: *foot and mouth disease virus*; PCV2: *porcine circovirus 2*; PPV: *porcine parvovirus*; PRRSV: *porcine reproductive and respiratory syndrome virus*; SPV: swine papilloma virus;

Depending on pathogen, other less important forms of the seminal contamination should be considered. Among them, it can mentioned the transmission through aerosols, urine, fo‐

Finally, for complete determination of the level for the disease transmission risk in a farm, the hygienic and sanitary standards adopted in this farm should not be disregarded. In prac‐ tice, it is observed that farms which do not provide effective vaccination programs and present failures in sanitary practices are more subject to contamination of the animals. The

With the high spread of the AI technique, semen has become an important vehicle for dis‐ semination of pathogenic agents, either by previous infection of the male' reproductive tract

SVD: swine vesicular disease virus; TGEV: transmissible gastroenteritis virus.

mites, people, vectorial insects, birds and wild mammals [5].

animals under these environmental conditions face a constant challenge.

**3. Major contaminants of semen during AI procedure**

Porcine adenovirus + Low Aujeszky diseasevirus + + African swine fever virus + + Blue eye disease virus + + CSFV + + *Porcine sapelovirus* + + FMDV + Low Influenza virus + Low PCV2 + + PPV + + PRRSV + + Reovirus + Low SPV ND + SVD + + TGEV + Very Low

**Agent Virus Isolation in Semen Potential risk for contamination**

The Potential for Infectious Disease Contamination During the Artificial Insemination Procedure in Swine

http://dx.doi.org/10.5772/52337

121

were experimentally proved.

When processing the semen, certain hygienic precautions should be taken during its dilu‐ tion and straw filling in order to prevent contamination. Regardless of the viral source, the storage and manipulation conditions are fundamental to predict the potential risk for con‐ tamination of the semen. It is known that the fresh semen is favorable to preservation and dissemination of the virus between species [6]. Therefore, the places where they will be in contact with the semen should be thoroughly sterilized to prevent contamination. There is a false impression that the antibiotics present in diluents can prevent bacterial contamination, but this detail should be cautiously considered, since the antibiotic doses contained in the seminal diluents might contain only the bacterial proliferation and are ineffective against some specific strains and virus [13].

Another factor to be considered is the insemination procedure itself. During AI, the main contaminative source is the feces, which is contaminated mainly by *Porcine sapelovirus*. Therefore, the care related to washing of the perianal region should be reinforced in order to avoid contamination. Other agents which may be found in the feces such as *Escherichia coli*, *Salmonella sp*., *Rotavirus A*, Porcine Adenovirus, when introduced into uterus through in‐ semination pipette, may cause the infection of the uterus and consequently leads to reduc‐ tion of fertility and litter size.

Concerning to the intrinsic contamination forms, many local and systemic diseases may move towards the reproductive tract and are transmitted via semen. Those diseases can be divided into viral and bacterial diseases. In relation to viral diseases, some have more poten‐ tial risk for transmission, as presented in Table 1.

Most diseases that affect the reproductive tract and are caused by viral agents rather provoke classical clinical signs that serve as parameters for isolation of the animals be‐ sides avoiding the animal reproduction. However, some diseases may be transmitted via breeding, even when the animal shows no clinical signs becoming an even greater prob‐ lem, since it is not possible to identify the infected animal [14]. It is believed that the pe‐ riod over which there is greater release of viral load is when the animal shows the clinical stage of the disease [15].

In cases of the appearance of clinical signs, generally the males are not used for reproduction. Furthermore, the males usually refuse to make the natural mating during those situations. In addition, there is the guarantee of the reduced risk for transmission the disease, unlike when there is no apparent infection. Finally, the insemination of the sows infected with a semen does not necessarily result into contamination of the female and the onset of the clinical disease in the same one. Thus, the complexity of the conditions required for establishment of this process were experimentally proved.

animal is serum-negative for the infection [10], this elimination may still occur under contin‐ uous or intermittent way during the months after infection [12]. Another measure that can be taken in order to reduce contamination is the elimination of the first ejaculatory jets, that are characterized by high microbial contamination, therefore obtaining a better quality of the semen. The environmental contamination is also a factor to be considered during the col‐ lection procedure. Thus, the sanitary procedure of either male' preputial region and the dummy sow used for collection are routine procedures to avoid an eventual contamination

When processing the semen, certain hygienic precautions should be taken during its dilu‐ tion and straw filling in order to prevent contamination. Regardless of the viral source, the storage and manipulation conditions are fundamental to predict the potential risk for con‐ tamination of the semen. It is known that the fresh semen is favorable to preservation and dissemination of the virus between species [6]. Therefore, the places where they will be in contact with the semen should be thoroughly sterilized to prevent contamination. There is a false impression that the antibiotics present in diluents can prevent bacterial contamination, but this detail should be cautiously considered, since the antibiotic doses contained in the seminal diluents might contain only the bacterial proliferation and are ineffective against

Another factor to be considered is the insemination procedure itself. During AI, the main contaminative source is the feces, which is contaminated mainly by *Porcine sapelovirus*. Therefore, the care related to washing of the perianal region should be reinforced in order to avoid contamination. Other agents which may be found in the feces such as *Escherichia coli*, *Salmonella sp*., *Rotavirus A*, Porcine Adenovirus, when introduced into uterus through in‐ semination pipette, may cause the infection of the uterus and consequently leads to reduc‐

Concerning to the intrinsic contamination forms, many local and systemic diseases may move towards the reproductive tract and are transmitted via semen. Those diseases can be divided into viral and bacterial diseases. In relation to viral diseases, some have more poten‐

Most diseases that affect the reproductive tract and are caused by viral agents rather provoke classical clinical signs that serve as parameters for isolation of the animals be‐ sides avoiding the animal reproduction. However, some diseases may be transmitted via breeding, even when the animal shows no clinical signs becoming an even greater prob‐ lem, since it is not possible to identify the infected animal [14]. It is believed that the pe‐ riod over which there is greater release of viral load is when the animal shows the

In cases of the appearance of clinical signs, generally the males are not used for reproduction. Furthermore, the males usually refuse to make the natural mating during those situations. In addition, there is the guarantee of the reduced risk for transmission the disease, unlike when there is no apparent infection. Finally, the insemination of the sows infected with a semen does not necessarily result into contamination of the female and the onset of the clinical disease in

of the semen outside the animal' body.

120 Success in Artificial Insemination - Quality of Semen and Diagnostics Employed

some specific strains and virus [13].

tion of fertility and litter size.

clinical stage of the disease [15].

tial risk for transmission, as presented in Table 1.


**Table 1.** Presence of the viral agents in semen of pigs and the risk for their transmission through AI (Adapted from [14] and [6]. ND: No data; CSFV:*classical swine fever virus*; FMD: *foot and mouth disease virus*; PCV2: *porcine circovirus 2*; PPV: *porcine parvovirus*; PRRSV: *porcine reproductive and respiratory syndrome virus*; SPV: swine papilloma virus; SVD: swine vesicular disease virus; TGEV: transmissible gastroenteritis virus.

Depending on pathogen, other less important forms of the seminal contamination should be considered. Among them, it can mentioned the transmission through aerosols, urine, fo‐ mites, people, vectorial insects, birds and wild mammals [5].

Finally, for complete determination of the level for the disease transmission risk in a farm, the hygienic and sanitary standards adopted in this farm should not be disregarded. In prac‐ tice, it is observed that farms which do not provide effective vaccination programs and present failures in sanitary practices are more subject to contamination of the animals. The animals under these environmental conditions face a constant challenge.
