Abstracts - Genetics and reproduction

This work establishes fundamental time points in placenta development corresponding to fetal growth and microfold formation that may influence fetal growth and impact fetal survival.

Social genetic effects offer the opportunity to breed for improved behaviour while maintaining performance.

In conclusion, genomic techniques answered some important questions about this critically endangered mammal and can be a valuable toolset to inform future conservation management in other species as well.

Heat stress and reduced feed intake compromised intestinal integrity in pigs, and zinc AA complex source mitigates some of these negative effects.

This study showed the potential to select on longer interval from last insemination to culling in days and thereby select against sows to be culled within the reproduction, locomotion, accident, general disorder and peri-partum cull class and to be culled at the end of a parity.

The A allele is clearly associated to larger (up to 20.4%) intramuscular fat content and also to 9.9% lower backfat thickness.

The results are valuable for the genetic selection of animals to explore the consequences on production and robustness traits.

These results showed that the highest assurance of providing PRRSV-negative semen to sow farms should be based on rRT-PCR testing of serum collected at the time of semen collection.

Almost all the sperm that colonize the uterotubal junction had a normal morphology, with part of the abnormal sperm having been discarded in the backflow and part selected/modified on their way to the oviduct.

Prevention of viral semen contamination should be the primary focus because it is easier to prevent contamination than to eliminate viruses once present in semen.

A minimum age is proposed for young boars to qualify for selection, or alternatively, age-related semen quality thresholds in young boars should be established.

Vaccination in females did not alter carcass and meat quality, and specific interests should consider reproductive behavior in free-range conditions.

More than 85% of primiparous sows can be successfully post-cervical inseminated with doses containing 1.5 × 109 sperm cells in the absence of the boar during insemination without impairing the reproductive performance.

In conclusion, premature births increase the number of intra-partum deaths and result in lower birthweights, the presence of apnoea, and severe metabolic alterations in piglets.

This study evaluated the effect of full physical boar exposure at different stages of lactation on the incidence of lactation oestrus in both primiparous and multiparous sows.

In conclusion, a greater PRL/P4 ratio 24 h prepartum, characterized by lower P4 concentrations and a trend for greater PRL concentrations peripartum, led to increased colostrum yield in primiparous sows.

Our results suggest that at least at the chosen stocking densities, parity and space allocation have minimal effect on a number of commonly-used welfare measures.

On the basis of the presented results, it should be noted that the use of oxytocin into insemination doses improves the farrowing rate and other parameters of the reproductive performance of sows.

High PBA in parity 1 can be used to predict that a sow will have high reproductive performance and lifetime performance.

These results indicate that AI using 2.0 × 109 FTS can result in acceptable pregnancy rates and litter sizes but with no measurable benefit for addition of prostaglandin.

The aim of this study was to evaluate the effect of including different percentages of Duroc breed in maternal line and gender on meat quality and intramuscular and subcutaneous fatty acid composition.

Organoleptic ham criteria for immunocastrated males hams were equivalent to those found for surgically castrated males and gilts hams, demonstrating the efficacy of vaccination in these study conditions.

The main objective of this thesis was to develop a protocol to efficiently apply flow cytometric sex-sorting procedure on boar spermatozoa.

These results suggest that some salivary metabolites could be biomarkers of the pre‐pubertal stage in gilts.