Boar Differences In Artificial Insemination Outcomes: Can They Be Minimized?

Abstract

Contents In Western countries, where pig breeding and production are intensive, there is a documented variability in fertility between farms with boar‐related parameters only accounting to 6% of this total variation of in vivo fertility. Such low boar effect could be a result of the rigorous control of sires and ejaculates yielding AI‐doses exerted by the highly specialized AI‐centres that monopolize the market. However, some subfertile boars pass through these rigorous controls and consequently reach the AI‐programmes. Here, we discuss why testing young boars for chromosomal defects, sperm nuclear chromatin integrity and in vitro fertilizing ability can be discriminative and economically sound for removing these less fertile boars. Alongside, we discuss why boars differ in the ability of their sperm to tolerate cryopreservation or sex sorting.

Characterization of the porcine seminal plasma proteome comparing ejaculate portions

“…As boar ejaculates are traditionally hand-collected, the SRF is the only fraction sampled, discarding the post-SP and thereby most of the total SP. However, the ejaculate collection method is currently shifting from manual to semi-automated, for hygienic and labour reasons, moving from collecting just the SRF to the entire ejaculate [18]. The change increases the relevance of SP, as the large SP-volume of post-SRF fraction will now become a part of the collected ejaculate.…”

Will AI in pigs become more efficient?

“…This substantial structural progress has also led AI-centers towards more accurate and precise semen assessment by incorporating technologies such as CASA and/or flow cytometry [11], resulting in better fertility outcomes on-farm of the dispensed AI-doses. Despite progress, it is estimated that between 5-7% subfertile boars still remain "hidden" in AI-centers [27], percentage that could be increased substantially as sperm numbers/AI-dose decreases. It is well known that lowering sperm numbers/AI-dose emerge subfertility problems in boars with previous high fertility using conventional AI- …”

“…To achieve it, changes in the AI-doses production system are necessary, as switching from pooled doses to single-boar doses in order to maximize genetic diffusion of merit boars and, thereby, optimizing breeding farm productivity [5]. Consequently, the current picture of AI-centers is moving from classical small centers housing a few boars usually integrated within breeding farms, towards large, independent and technically highly specialized centers housing a large number of healthy and genetically superior boars that produce, following strict regulations and guidelines to prevent disease spreading, large daily numbers of ready-to-use high-quality liquid-stored AI-doses [27]. This substantial structural progress has also led AI-centers towards more accurate and precise semen assessment by incorporating technologies such as CASA and/or flow cytometry [11], resulting in better fertility outcomes on-farm of the dispensed AI-doses.…”

Markers for Sperm Freezability and Relevance of Transcriptome Studies in Semen Cryopreservation: A Review

“…Moreover, selection of animals with good semen freezability for cryopreservation and AI is a crucial step to improve the fertility levels of frozen-thawed semen [9,10]. Furthermore, in some animal species, despite satisfactory results of fertility in liquid-stored semen, frozen-thawed semen does not give acceptable fertility results in AI practice in the commercial industry [2,3,9].…”

“…In the artiicial insemination (AI) industry, there is a need to optimize the selection strategy for individuals with good freezability, so as to incorporate this information in the breeding program to improve the fertility of post-thaw semen [2,3,7]. Moreover, selection of animals with good semen freezability for cryopreservation and AI is a crucial step to improve the fertility levels of frozen-thawed semen [9,10]. Furthermore, in some animal species, despite satisfactory results of fertility in liquid-stored semen, frozen-thawed semen does not give acceptable fertility results in AI practice in the commercial industry [2,3,9].…”