Agglutination entails the accumulation of sperm in the ejaculate. Most times this accumulation of sperm cells may be characterized by the head-head bond or the tail-tail bond between sperm cells.
The main causes of an increase in the agglutination degree are the following:
- Tapioca: it may cause sperm agglutination. That is why we need to use a filter during collection, so as to be able to retain as much tapioca as possible.
- Temperature of the thermos for collection and / or water bath. If temperature is not adequate (too high or abrupt changes), it can produce a thermal shock of the spermatozoa, appearing an increase in the agglutination degree of the samples.
- Heat stress in boars: Temperatures above 27ºC may cause heat stress in boars. Temperatures above 31ºC provoke severe heat stress. When heat stress appears, the seminal quality begins to be affected approximately two weeks after the beginning. It is characterized by a decrease in motility, an increase in the percentage of abnormal forms and an increase in the agglutination degree. Besides, situations that produce fever in boars (infectious processes, some vaccines) cause a qualitative change of the ejaculates (increase in percentage of abnormal forms and / or agglutination). Therefore, the monitoring of the sanitary condition of the boars is recommended.
- Quality of distilled water used for dilution. The presence of certain salts and / or metal ions produces agglutination.
- Cleaning and non-toxicity of the material for collection. (Cups for collection and/or single-use bags with filter are recommended). It is important to collect and process the ejaculates with the greatest possible hygiene, performing a correct emptying of the foreskin and using the “double glove” technique.
- Bacterial contamination of semen. The consequence of contamination in ejaculates is a poor semen preservation, as it causes agglutinations, excessive damage of acrosomes, low motility and death of the sperm cells with the consequent loss of seminal doses.
On the other hand, when using the contaminated doses, the dissemination of specific or non-specific infections is facilitated. It causes vulvar discharges, delay in the coming of the estrus, failures in embryo implantation and, in the worst cases, metritis, endometritis, cystitis or pyelonephritis, so control is very important. Therefore, the extender used must be capable of controlling the bacteria that are in the insemination center (boar stud).
- The contamination of the ejaculate with urine causes an increase in agglutination.
- Use of latex gloves and other equipment in contact with semen, stored in sub-optimal conditions and / or incorporating substances toxic to the sperm cell. The use of “powder free” vinyl gloves is recommended for collection.
- Immune and / or inflammatory processes of the reproductive tract, such as epididymitis, may cause agglutination.
Agglutination may appear in many ejaculates and the causes can be many. It is recommended to monitor the health of the boars, as well as perform the collections and processing of the ejaculates with maximum hygiene. Very important to say that any alteration in any of the points mentioned above can also cause sperm death. Consequently, we recommend identifying and locating the source of the problem as soon as possible, to re-establish normality in the farm and avoid the possible spreading to other animals and / or the drop in farm performance results.