Spermatogenesis in boar can be influenced by many factors, which will determine a variation of seminal parameters. A better knowledge of the opportunities to control the variation of semen quantity and quality can increase the efficiency of swine reproduction units.
The aim of this study was to examine the seasonal variation of semen, in order to offer a solution against “seasonal infertility” in pigs.
The study was conducted on a number of 537 ejaculates, from 31 Pietrain boars housed in standardized conditions in terms of temperature, humidity and light schedule.
Semen was collected by manual method, and examined using the beaker, and CASA system (CEROS II).
The results, expressed as mean values, were as following: Volume showed higher values in the summer (218.7 ml) and lower in the autumn (155.7 ml); Total number of spermatozoa/ejaculate was higher in the summer (95.9×109) and lower in the winter (74.3×109); Semen concentration was higher in the autumn (571.6×106/ml) and lower in the summer (454.8×106/ml); Total number of motile spermatozoa/ejaculate showed higher values in summer (79.5×109) and lower in winter (65.4×109); % of Total motility was higher in the winter (87.9%) and lower in the summer (82.3%); Total number of progressive spermatozoa/ejaculate was higher in summer (52.7×109) and lower in autumn (44.2×109); % of Progressive motility was higher in winter (61.4%) and lower in autumn (52.3%).
The results contradict those of other authors, who studied the semen from boars held in classic conditions. This fact suggests that the standardization of exploitation conditions of boars by maintaining a controlled climate in the farm can reduce the effects of heat stress on spermatogenesis during summer, offering a great opportunity against seasonal infertility and high variations of semen parameters during a year.