How should an immunisation programme be implemented at the Insemination Centre?
Vaccines have a series of adverse reactions, depending on their aggressiveness. The most common and milder reactions are local (pain and redness at the injection site). However, systemic reactions can also occur (fever, sickness, loss of appetite). To reduce the negative effects of vaccines, analgesics and/or anti-inflammatory drugs can be administered.
In the particular case of immunisation at the insemination centres, vaccines can lead to a deterioration in the quality of the ejaculates (associated with the adverse reactions listed above). More aggressive vaccines lead to an increased percentage of abnormal forms and agglutination, whereas immunisation with more benevolent vaccines is associated with an increase in the percentage of cytoplasmic droplets and a small decrease in motility.
It is advisable, therefore, to carry out vaccination in stages. This way, a production of a homogeneous dose can be kept throughout the year. Only if staff responsible for vaccination have experience and are well-versed in the effects of each type of vaccine, can vaccination of all animals at once be considered.
What is the best way to calculate the calibration curve of a colorimeter?
To calculate the straight line, it is recommended to use several types of ejaculates (from very concentrated to very dilute, but especially within the concentration range usually encountered), so that the a wide range of possible situations can be catered for.
Do not touch the smooth part of the cell and use only those in good condition.
If possible, use ejaculates from several boars and from several different breeds.
The ejaculates used to calibrate the colorimeter must be good quality ejaculates. In other words, they must have good sperm motility, be in a suitable range for morphological anomalies and especially not agglutinate and/or be significantly contaminated.
It is advisable to recalculate the conversion equation at least twice a year due to the variability between ejaculates, particularly between winter and summer seasons.
It is also advisable to check the line equation every month to prevent large variations and deviations.
Reviewing the calibration curve is especially advisable if there is a significant influx of boars to the insemination centre or if you make changes to the way of working; for example, if you decide to collect only the rich fraction of the full ejaculate.
How should you handle males with poor sperm quality?
The economic value of a male is highly significant and their removal has a major impact on the performance of the insemination centre. Therefore, correctly determining when they need to be removed is important. The most frequent reason for removing males from insemination centres is the poor quality of their semen. A male may experience a temporary decrease in the quality of its ejaculates at any particular time of its productive life. This may be due to several factors, acting either independently or jointly. It is important to know when the male starts to have problems and identify possible causes of the decline in quality. Thus, a period of critical environmental conditions, a change in handling or diet, veterinary treatments, etc are all factors that can affect the sperm quality of males in the centre. Once a possible cause for the decline in semen quality is suspected, the type of action to perform may be considered. The most immediate is to deal specifically with the boar, give him a week's rest and watch his development over a couple of months. If an improvement is not seen in semen quality, the permanent removal of the animal can be considered.
Which diseases may be transmitted through semen?
One of the main advantages of artificial insemination is the reduction of the sanitary risk associated to natural mating. Nevertheless, semen may also act as vehicle for the transmission of serious diseases.
Among the infectious agents that may be present in semen and therefore transmitted through artificial insemination are: PRRS; FMD; CSF; ASF or Brucellosis. Although transmission risk is low, the serious consequences that some of these diseases have should oblige semen producers to make strict sanitary controls to boars and seminal doses.
Which is the objective of quarantine in an AIC?
The quarantine period has three fundamental objectives:
1. Guaranteeing the sanitary status of the centre: with this aim, at least two serological tests should be carried out and “new” animals should be included in the sanitary programme of the centre.
2. Favouring the adaptation of the boar to his new environment and starting his training.
3. Making a first classification of the boars, discarding males with serious problems not suitable for production.