Fertility of sows after intracervical or intrauterine insemination with different spermatozoa number in reduced volume doses

Abstract

Modern intensive pig production demands an increasing number of insemination doses per ejaculate of genetically superior boars. In order to achieve such a result the possibility of producing insemination doses in both reduced volume and spermatozoa count without decreasing the fertility of sows is studied. In this trial we studied the effect of insemination with reduced volumes of semen (50 mL) and varied spermatozoa count (4, 2 or 1x109). Insemination was performed by the classical (intracervical) or by the new (intrauterine) techniques and the basic fertility parameters (farrowing % and litter size) were measured. The farrowing value decreased with decreasing spermatozoa numbers after intracervical and intrauterine insemination. However, the farrowing value, regardless of spermatozoa numbers, was significantly higher after intrauterine insemination (83.3%, 76.7%, 66.7%) compared to the classical intracervical insemination (73.3%, 66.7% and 50%). Litters size did not vary significantly depending on the applied insemination procedure or spermatozoa number. These results indicate that application of the new intrauterine insemination procedure enables the use of doses with a smaller volume and spermatozoa number, at the same time obtaining a satisfactory farrowing and litter size. This opens the possibility of obtaining a significantly higher number of doses per ejaculate when compared to the classical intracervical insemination procedure. In such a way can be increased significantly the degree of reproductive exploitation of genetically superior boars

Sow fertility after insemination with varying doses of volume and spermatozoa count

“…The finding of the present study confirm the results of others in that intrauterine insemination with doses of various volumes (100, 85, 50, 30, and 20 mL) and spermatozoa counts (4, 3, 1.5, and 1 × 10 9 ), produced farrowing rates ranging from 78% to 96% with litter sizes of 9 to 12 live-born piglets (7)(8)(9)(10)(11)(12)(13)(14). Additionally, a key feature in the success of intrauterine insemination is the deposition of semen in the cranial parts of the female reproductive system (body of uterus, uterine horns, uterotubal junctions, or oviducts).…”

“…Previous studies reported that optimal farrowing rates in sows could be achieved if insemination is performed around 24 h before ovulation, with doses containing 2 × 10 9 spermatozoa. An increase in the number of spermatozoa above this value has no impact on the achieved fertility, whereas a reduction in the number of spermatozoa below 2 × 10 9 results in lowered fertility in inseminated sows (4,10,19). Those studies showed that with intrauterine insemination, doses of onehalf of the volume and the number of spermatozoa that are employed with classic intracervical insemination will produce a satisfactory farrowing rate and litter size.…”

“…To overcome this problem, AI doses of reduced volume and spermatozoa numbers delivered by the intrauterine route have received considerable attention. However, an overriding consideration in using reduced AI doses and new delivery techniques is that when compared with the classic intracervical insemination, sow fertility rates should not be compromised (7)(8)(9)(10)(11)(12). Due to the high cost of high genetic quality boars used in the Serbian commercial pig production, it is necessary to increase the number of insemination doses per boar per year, while maintaining the sow fertility rate.…”

Highlights on Artificial Insemination (AI) Technology in the Pigs

“…The fertility of liquid-stored boar semen depends mainly on the following factors: initial ejaculate quality and frequency of semen collection, extender type, storage temperature and duration, sperm number per AI dose, insemination volume, number and timing of inseminations relative to ovulation at each estrus as well as the site of semen deposition in the female genital tract (16,39,45,(77)(78)(79)(80)(81)(82)(83)(84)(85)(86)(87)(88)(89)(90)(91)(92). In addition, a number of factors can also influence the fertility levels in pig farms, including boar breed and age, parity and lactation length, weaning-toestrus interval, season, stress, nutritional status and inseminator skills (80,85,86,88,91,(93)(94)(95)(96)(97)(98)(99)(100).…”