Correlations between some Parameters of Raw and Stored Semen in Boar

Abstract

The preservation in liquid form, at 17°C for several days is still the most used method of semen preservation in boar. In these conditions, it would be of great value to know the factors that can predict the capacity of an ejaculate to maintain its biological value over preservation period. This study aimed to identify the correlations between some parameters of raw semen, and those of extended semen, stored in liquid form, for three days at 17°C. Over 1000 ejaculates were collected by means of manual method and artificial vagina over a period of two years from 400 mature boars housed in a specialized unit in Germany. The semen was examined immediately after collection (before dilution) as well as after three days of preservation. All the parameters (except the volume) were determined by means of computerized instruments. The examination of raw semen was performed using SQA-Vp, while the stored semen was analyzed using Spermvision version 3.7. All data were processed with IBM SPSS Statistics version 21. The Pearson correlation revealed no strong correlation between any of the raw semen parameters when analysed together with stored semen parameters. However, some moderate or weak correlations were found, for example a positive correlation between motility of raw semen and motility of stored semen (p<0.01), a positive correlation between percentage of morphological normal sperm in raw semen and the motility of stored semen (p<0.01), a negative correlation between the concentration of raw semen and the linearity and wobble coefficient in stored semen (p<0.01) as well as a couple other weak correlations. We conclude that, despite the fact that some correlations were revealed, unfortunately the analyzed parameters of raw semen have low predictive value on the parameters of extended semen after preservation at 17°C, and that the parameters of semen will behave differently from one ejaculate to another.

Presença da gota citoplasmática e seus efeitos na morfometria, cromatina e motilidade espermática e identificação de genes candidatos à seleção de parâmetros seminais de suínos

“…Despite the high positive correlation previously reported between total motility and progressive motility [60], several chromosomes regions explaining more than 1% of their additive genetic variance and candidate genes identified differed between them (Table 2). However, some chromosomes and positions were similar and there were two equal candidate genes for both -HSD17B11, HSD17B13.…”