P. Serra The author worked as an FAO Associate Professional Officer on the FAO/UNDP project, Strengthening of the Philippine Carabao Research and Development Center (PHI/86/005). His address is: Via Frate Giovanni 12, 40046 Ozanno (Bologna), Italy.
An artificial insemination (AI) gun set, Type 1, has been developed under the project, Strengthening of the Philippine Carabao Research and Development Center. The gun set should enhance reproductive performance of refrigerated semen under working conditions in remote areas. When compared with semen stored by cryopreservation, refrigerated semen has a higher sperm viability and conception efficiency in addition to lower processing costs. This simpler technology is suited to developing country situations as it does not require the availability of liquid nitrogen. Another AI device, Type 2, has been developed in an attempt to combine the benefits provided by Type 1 with the significant advantages offered by the standard AI straw gun.
The Type 1 AI gun set (Fig. 1) is composed of the following elements:
· AI gun body. This hollow rod is made of stainless steel, with a slightly cone-shaped head to allow a good seal with the apical portion of a disposable AI plastic sheath. The tail of the AI gun permits the connection of a "luer lock" or "cone 2" syringe.
· Case. Made of stainless steel, the case provides protection from microbiological agents, allowing transportation in a sterile condition. The case and AI gun can be sterilized together in an oven after having been cleaned with water.
· Brush. This permits cleaning inside the hollow rod to remove impurities and clots prior to sterilization.
· Ring latch. Made of plastic, the latch fits closely to the AI gun and disposable sheath.
The Type 2 AI set (Fig. 2) has three components that differ from those of the standard AI straw gun:
· Adaptor. This is the core part of the device. At the anterior end of the hollow rod (portion AB) there is a screw thread for attachment of the adaptor. The sterilizable "O" ring, inserted at the end of the adaptor's screw thread, prevents leakage where the rod and adaptor fit together. Cross section 1 (portion AB of the adaptor) has a dimension that simulates the 0.5 ml French straw diameter. The disposable AI sheath can thus be fitted to the adaptor as with a straw.
· Case. This provides the same protection as Type 1.
· Tail of AI gun. This can be connected with a "luer lock" or "cone 2" syringe as a semen pumping device.
Type 1 AI gun set - Type 1 du pistolet d'insémination artificielle - Jeringuilla de inseminación artificial de tipo 1
Type 2 AI gun set - Type 2 du pistolet d'insémination artificielle - Jeringuilla de inseminación artificial de tipo 2
There are no major differences between the AI operations of Type 1 and Type 2 and those of the basic AI straw gun. The AI technician should connect a syringe at the tail of the AI gun, fit a disposable AI sheath and withdraw the desired quantity of semen which can be packed into recyclable glassware (vials, ampoules or test-tubes placed inside a thermos or foam ice-box). Type 2 can be used either as a standard AI 0.5 ml straw gun or as an AI catheter simply by removing or inserting the adaptor. To avoid semen cross-contamination, breeding stations adopting this AI method should provide one AI gun for each sire being used.
When compared with AI glass or plastic catheters, the Type 1 and 2 AI devices provide the following advantages:
· Safety of use. The disposable AI sheath for each AI performed avoids the risk of transmitting gynaecological infections from animal to animal.
· Strength and durability. Being made of stainless steel, these AI devices should have a long life.
· Simplicity of use. Performing AI is quite easy since this device has the same rigidity but a smaller outside diameter than the glass catheter.
· Versatility. As in the case of catheters with disposable sheaths, these two devices can perform either therapeutic intra-uterine ravages during treatments of uterine infections or collections of specimens for microbiological examinations of the uterine microflora.
Furthermore, any type of sterilizable and recyclable container can be used to store the refrigerated semen.
Type 2 combines the additional benefits of the standard AI straw gun.
A first survey conducted under the PHI/86/005 project did not find any significant growth of bacterial and/or fungal flora in the semen after performing several AIs with the Type 1 AI gun. The intention was to develop simple, functional and safe AI tools. However, it is not suggested that these AI devices could be a replacement for the basic AI straw gun in all AI conditions. Such new types of A1 guns can be useful in some situations, particularly when the successful improvement of livestock through AI in developing countries can be best achieved by the rational utilization of both frozen and refrigerated semen methodologies.