The objective of this study was to evaluate the effects of litter size and parity on the overall reproductive performance of highly prolific sows, with special emphasis on factors influencing the incidence of mummified fetuses and prenatal mortality. Data from 950 litters produced by 444 highly prolific DanBred sows were analyzed. The independent effects of parity and litter size on the total number of piglets born, born alive, stillborn, and mummified fetuses were evaluated. A linear mixed-effects model (LMM) with sow as a random intercept was applied to account for the repeated-measures data structure; group differences were evaluated using Wald χ² tests. Litter size significantly affected all evaluated reproductive traits (P < 0.0001). Hyperprolific litters achieved the highest number of live-born piglets but also exhibited a significant increase in both stillborn and mummified fetuses (P < 0.0001). Parity significantly influenced the number of total born, born alive, and stillborn piglets (P < 0.01), with a severe increase in stillbirths observed in older sows at parity 7 and 8. Notably, parity had no statistically significant effect on the incidence of mummified fetuses (P = 0.127), suggesting that mummification is primarily associated with larger litter sizes and limited uterine capacity rather than maternal age per se. To optimize production and reduce perinatal losses, targeted management of sows beyond the fifth parity should be considered, as advancing parity significantly increased stillbirth rates. Fetal mummification is predominantly driven by intrauterine crowding in large litters rather than by maternal age.
Ear necrosis is prevalent in weaned pigs reared in intensive production systems and is associated with welfare, other health, and production concerns. However, there is a lack of knowledge about the physiological alterations in pigs with ear necrosis. This study used a panel of 11 analytes in oral fluids to explore associations between ear necrosis and markers for stress (cortisol, alpha-amylase, butrylcholinesterase (BChE)), inflammation (haptoglobin), immune activation (adenosine-deaminase, ferritin, interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor alpha, interferon-gamma), and general homeostasis (creatine kinase). Pigs (n = 410) in 36 mixed-sex pens were scored for ear necrosis once per week for 6 weeks after weaning. Oral fluid samples were collected from pens once per week and from 61 individual pigs at week 5 post-weaning. Pens were categorised based on the proportion of pigs in the pen with ear necrosis at each week: Zero (0
Transmission of the Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) may occur through both direct and indirect routes. Hematogenous transmission of PRRSV has been described from infected to susceptible pigs via repeated use of the same needle with intramuscular syringes or the use of needle-free injection devices (NFID). Indirect transmission may also occur through injection devices that can act as fomites. The purpose of this study was to evaluate the risk of residual PRRSV-1 modified live (MLV1) vaccine strains in automatic intramuscular syringes with needle (AIMS) or in NFID after implementation of cleaning and disinfection procedures. Three different MLV1 vaccines were evaluated. Injection devices were sampled (internal injection mechanism and external surface) unwashed (UW), after washing (W) or after washing and disinfection (WD) procedures, just after the vaccination (D0) or after seven days of quarantine (D7). The samples were tested by PRRSV RT-PCR and by virus isolation. In the unwashed condition, PRRSV genome was detected on external surfaces and internal mechanisms of almost all AIMS and NFID devices. Infectious VP046 bis strain was recovered from the interior of an AIMS 7 days after use. Whatever the vaccine used, after washing only or washing and disinfection, a marked decrease in PRRSV genome load was noticed in injection mechanisms of injections devices. For AIMS, PRRSV RNA was still detectable, always with Ct > 30 (mean Ct 34.0 ± 2.2). For NFID, PRRSV genome was detected in all injection mechanisms as well, but with Ct < 30 (except one NFID - mean Ct 27.0 ± 2.5). On external surface, PRRSV was not detected for any AIMS after maintenance procedures, but was detected on 75
Periweaning Failure-to-Thrive syndrome (PFTS) is an emerging syndrome characterized by progressive growth retardation, anorexia and debilitation in piglets during the 2–3 weeks post-weaning. Since its first description in 2008, the syndrome has been reported in several countries and represents an important concern for the swine industry due to its impact on productivity and mortality. A consistent pathological feature of affected animals is thymic atrophy, suggesting a possible role of thymic dysfunction and altered thymic hormone production in the pathogenesis of the syndrome. The present study aimed to evaluate histopathological and histomorphometric changes in the thymus of PFTS- affected piglets and to investigate their association with leukocyte counts, serum thymulin levels and endocrine thymus functionality. The histopathological study revealed that piglets with clinical signs compatible with PFTS showed different degrees of thymic atrophy ranging from mild to severe, whereas healthy animals displayed normal thymic morphology. On the other hand, the histomorphometric results revealed a significant reduction in the cortex/medulla ratio in affected piglets, and this reduction became more pronounced as the severity of the thymic atrophy increased, although the size of Hassall’s corpuscles did not differ significantly between healthy and affected animals. Hematological analysis revealed progressive decreases in several leukocyte populations, particularly total lymphocytes and large lymphocytes, associated with increasing severity of thymic atrophy. Serum thymulin concentrations were significantly lower in affected piglets and showed a negative correlation with the degree of thymic atrophy. When looking at gene expression, significant reductions in prothymosin alpha and thymopoietin in animals with severe thymic atrophy were seen, while most β-thymosins showed minimal variation. Overall, the correlation analyses supported a strong link between thymic atrophy, alterations in immune cell populations and reduced thymulin levels. Our results support the hypothesis that thymic atrophy and reduced serum thymulin production are closely associated with the development of PFTS and may contribute to the immune alterations observed in affected piglets. Additionally, serum thymulin levels may provide a useful biomarker for the early detection of thymic dysfunction in pigs. Further research is needed to clarify the underlying mechanisms of this syndrome and to determine the role of other possible factors in its development.
Respiratory disease remains highly prevalent in pig production and constitutes a major health and welfare challenge worldwide. However, most studies assessing pig welfare impairment from respiratory disease rely on isolated animal-based indicators, limiting integration across welfare domains. This study aimed to quantify welfare impairment from respiratory disease in fattening pigs (8–10 weeks of age) using indicators aligned with the Five Domains Model. A survey using adaptive conjoint analysis was conducted with animal welfare researchers (n = 32) and practising swine veterinarians (n = 22). Respondents completed pairwise comparisons of profiles defined by combinations of five welfare indicators—appetite, coughing, respiratory distress, play behaviour, and exploratory behaviour—each expressed at increasing severity levels. Based on respondents’ choices of which profile represented greater welfare impairment, indicator importance scores and level-specific contributions to pig welfare impairment from respiratory disease were estimated. Across respondent groups, severe respiratory distress was perceived as the largest contributor to pig welfare impairment from respiratory disease, with an estimated contribution of 29.8
