Search Results (11)

Biosecurity is essential in livestock farming to prevent the spread of diseases, ensure animal welfare, and maintain farm sustainability. In Portugal, small ruminant farms are predominantly extensive and small-scale, and most of them are familiar, especially in the northern and inland regions. Thus, biosecurity implementation on these farms is low due to factors such as an aging livestock farmer population, poor training, limited veterinary support, and economic constraints. This study, the first to assess biosecurity on Portuguese small ruminant farms, evaluated compliance levels and the influence of sociodemographic factors. A cross-sectional study was conducted between July 2023 and April 2024, through structured interviews with 276 farmers. A 32-question checklist covering nine biosecurity categories was used to assess compliance. The results revealed poor implementation of key biosecurity measures, particularly cleaning and disinfection, quarantine protocols, and visitor control. Inadequate premises infrastructure, including the absence of quarantine areas, isolation facilities for sick animals, and farrowing rooms, further hampered disease prevention. Compliance was influenced by farmers’ age, education level, herd size, and production. Larger farms, particularly dairy farms, demonstrated better biosecurity practices, likely due to better management and infrastructure. This study highlights the challenges of implementing biosecurity measures on small-scale, extensive farms and argues that standardized plans are ineffective. Instead, region- and farm-specific strategies are needed, considering the socioeconomic realities of farmers. Improving farmers’ education and access to veterinary services is crucial. Furthermore, public policies should provide financial incentives and educational programs to improve biosecurity without compromising farm viability. Strengthening biosecurity on small ruminant farms is vital to protecting animal and public health and ensuring the long-term sustainability of rural communities in Portugal. Full article

Background: Early gut microbiota (GM) dysbiosis can affect a child’s health and has been linked to the onset of pathologies later in life. Breast milk is recognized as a major driver of the structure and dynamics of an infant’s GM. In addition to nutritious and prebiotic compounds, milk contains a microbiota that is shaped by several maternal factors, including gut microorganisms and medications. However, the impact of the latter on the milk microbiota is still largely unknown. Here, we investigated the effects of amoxicillin on the milk microbiota and GM of lactating Göttingen Minipigs sows, a promising model for studying medication transfer during lactation. Methods: Three sows were given amoxicillin (7 mg/kg/day) for three weeks starting from the second week after farrowing. Fecal and milk samples were collected before and after treatment and profiled by 16S rRNA amplicon sequencing. Results: Göttingen Minipigs’ milk microbiota showed similarities to that of humans and conventional sows, with minor compositional shifts after treatment. At the genus level, we observed a decrease in Staphylococcus and o_Bacteroidales;Other;Other, and an increasing trend in the abundance of Streptococcus, Stenotrophomonas, f_Rhodobacteraceae;Other, Proteiniclasticum, f_Propionibacteriaceae;Other and Gemella. In contrast, as expected, the GM was strongly affected by amoxicillin, even at the phylum level. Conclusions: In addition to demonstrating the relevance of Göttingen Minipigs as a valid model for studying the impact of medications on maternal milk and GM, our findings suggest that the milk microbiota may be more stable during antibiotic treatment than the GM. Full article

In Poland, despite a decline in the pig population, pork consumption invariably remains high. For this reason, it is important to search for a potential reduction in pig production costs. One of the feasible solutions is to use sows of hybrid lines. Currently, several sow lines are available on the Polish market, such as CG36 (Choice Genetics). The aim of this study was to determine the level of reproduction performance in this line considering the effect of parity and farrowing season. Additionally, coefficients of phenotypic correlations between analysed reproduction performance parameters were determined. The experimental material comprised 112 females inseminated with semen of a boar of the Excelium line (Choice Genetics), which produced 336 litters. The investigated population was characterised by a high level of reproduction traits and young age at first farrowing (AFF), while the number of piglets born alive (NBA), the number of piglets weaned per litter (NW), and the number of piglets weaned per sow per year (PWSY) reached high, economically advantageous levels. Primiparous sows produced and reared lower numbers of piglets than multiparous sows, which indicates the need to maintain an adequate herd structure, with a maximum share of gilts at 30%. No effect of the season on values of reproduction traits was found, which shows optimal environmental conditions in the animal housing where the pigs were kept. Dependencies between the analysed traits confirmed the results reported by other authors, where NBA was highly positively correlated with LW, although LW increased with an increase in NBA. No correlations were found between PWSY and the other traits. In turn, the observed coefficients of phenotypic correlations indicate that in order to reduce AFF in CG36 sows, it is necessary to control FI. Full article

The integer-order delay of proportional–integral multi-resonant-type repetitive control (PIMR-RC) cannot provide excellent control performance for grid-tied inverters when the grid frequency fluctuates. To address this issue and reduce control errors, a fractional delay PIMR-RC (FD-PIMR-RC) scheme is proposed. In addition, to reduce the computational load and memory consumption, a Farrow-structure fractional delay (FFD) filter is adopted. The digital filter with the Farrow structure is flexibly and efficiently used for fractional delay. For each new fractional delay, a large number of calculations and storage for the FFD filter coefficients are avoided, which significantly reduces the computational load and memory consumption. The parameter design of the FD-PIMR-RC scheme is provided in detail, including the implementation of fractional delay based on the Farrow structure. Then, a system stability analysis and parameter optimization are presented. Finally, simulations for the steady-state and dynamic responses are presented, and the validity of the proposed method is demonstrated. Full article

Diverse origins and causes are described for papyraceous mummifications of porcine foetuses, but the porcine reproductive and respiratory syndrome virus (PRRSV) is not one of them. In contrast, PRRSV is unlikely to cause mid-term placental transmission but may cause late-term abortions and weakness of piglets. This case report describes a sudden occurrence of mummified foetuses of various sizes and stillborns and delayed birth (>115 days) in more than 50% of sows from one farrowing batch, while newborn piglets were mostly vital. Neither increased embryonic death nor infertility was reported. Three litters with mummies, autolysed piglets and stillborn piglets were investigated, and infections with porcine parvoviruses, porcine teschoviruses, porcine circoviruses, encephalomyocarditis virus, Leptospira spp. and Chlamydia spp. were excluded. Instead, high viral loads of PRRSV were detected in the thymus pools of piglets at all developmental stages, even in piglets with a crown–rump length between 80 and 150 mm, suggesting a potential mid-term in utero transmission of the virus. Genomic regions encoding structural proteins (ORF2–7) of the virus were sequenced and identified the virulent PRRSV-1 strain AUT15-33 as the closest relative. This case report confirms the diversity of PRRSV and its potential involvement in foetal death in mid-gestation. Full article

Weaning is a critical period in a pig’s life. Piglets are confronted with abrupt changes to their physical and social environment, as well as management and nutritional changes. Weaning has always been associated with a growth check and is frequently accompanied by post-weaning diarrhoea in piglets. However, rapid increases in litter size in the last decade have increased within-litter piglet weight variation, with piglets now generally lighter at weaning, making the challenges associated with weaning even greater. Many interventions can be employed during the suckling period to ease the weaning transition for piglets. Pre-weaning strategies such as supervised farrowing (assistance with suckling and oxytocin provision), the provision of pain relief to sows around farrowing, split-suckling, early oral supplementation with glucose, bovine colostrum, faecal microbiota transplantation, feed additives and solid and liquid creep feeding (milk and liquid feed) have all been investigated. The objective of these strategies is to stimulate earlier maturation of the digestive tract, improve immunity, reduce latency to the first feed post-weaning and increase early post-weaning feed intake and growth. This review focuses in particular on: (1) pain relief provision to sows around farrowing, (2)split-suckling of piglets, (3) pre-weaning provision of supplementary milk and/or liquid feed, (4) other strategies to stimulate earlier enzyme production (e.g., enzyme supplementation), (5) other nutritional strategies to promote improved gut structure and function (e.g., L-glutamine supplementation), and (6) other strategies to modulate gut microbiota (e.g., probiotics and prebiotics). Correctly implementing these strategies can, not only increase post-weaning growth and reduce mortality, but also maximise lifetime growth in pigs. Full article

The multi-rate repetitive controller (MRC) can achieve zero steady-state error in tracking the reference current signal of grid-connected inverters, save the settling time effectively, and improve the running speed. However, when the grid frequency fluctuates, the harmonic suppression performance of MRC will degrade. Aiming at the problem of harmonic suppression performance degradation, a fractional-order MRC (FOMRC) based on the farrow structure fractional delay (FD) filter is proposed. Firstly, the equivalent digital model of MRC is established, and a Farrow structure fractional delay (FD) filter based on Taylor series expansion is selected as the internal model filter of MRC. The stability analysis and harmonic suppression characteristics of the FOMRC are analyzed. Then, the parameter design of FOMRC applied to an LCL single-phase grid-connected inverter control system is given. Finally, the simulation results show that the proposed method has better transient and steady-state performance than the CRC when the grid frequency fluctuates. Full article

In order to achieve higher system performance, a digital calibration technique for the sub-channel mismatches of time-interleaved ADCs (TIADCs) is proposed in this paper. The sine-fit-based estimation algorithm is introduced to estimate the channel mismatches and a calibration algorithm is proposed to compensate for the mismatches. Subsequently, the genetic algorithm (GA) is firstly utilized to detect the mismatch errors of the outputs of sub-channels after frequency domain filtering. The detected offset error and gain error are then corrected by performing the calibration algorithm, and the time errors are corrected by fractional delay filters based on Farrow structure. The spurious-free dynamic range (SFDR) is enhanced from 19.69 dB to 108.12 dB, and the signal to noise and distortion ratio (SNDR) is enhanced from 16.02 dB to 97.63 dB. The proposed technique is further validated on the FPGA. Compared with existing calibration techniques, the proposed technique has the advantages of simple algorithm structure, low hardware resource consumption, and high calibration accuracy and can be applied to the calibration of high-resolution (18-bit) TIADCs for low-frequency inputs. Full article

Dietary fiber intake during pregnancy may improve offspring intestinal development. The aim of this study was to evaluate the effect of maternal high fiber intake during late gestation on intestinal morphology, microbiota, and intestinal proteome of newborn piglets. Sixteen sows were randomly allocated into two groups receiving the control diet (CD) and high-fiber diet (HFD) from day 90 of gestation to farrowing. Newborn piglets were selected from each litter, named as CON and Fiber group, respectively. Maternal high fiber intake did not markedly improve the birth weight, but increased the body length, the ileal crypt depth and colonic acetate level. In addition, maternal high fiber intake increased the -diversity indices (Observed species, Simpson, and ACE), and the abundance of Acidobacteria and Bacteroidetes at phylum level, significantly increased the abundance of Bradyrhizobium and Phyllobacterium at genus level in the colon of newborn piglets. Moreover, maternal high fiber intake markedly altered the ileal proteome, increasing the abundances of proteins associated with oxidative status, energy metabolism, and immune and inflammatory responses, and decreasing abundances of proteins related to cellular apoptosis, cell structure, and motility. These findings indicated that maternal high fiber intake could alter intestinal morphology, along with the altered intestinal microbiota composition and proteome of offspring. Full article

Within the past 30 years, through ongoing technology and portability developments, real-time (b-mode) ultrasonography (RTU) has increasingly become a valuable diagnostic tool in assessing the female reproductive tract in swine. Initially applied in swine production to visually determine pregnancy status, RTU use has expanded to include assessment of the peri-pubertal and mature non-pregnant females as well. Transabdominal and transrectal modalities to visualizing the reproductive tract in swine have been reported with the transabdominal approach more common due to the fact of its ease of accessibility, animal/personnel safety, and reduced time to perform. Adjustable frequency transducers are preferred as they allow optimization of image quality at various depths. If a single transducer frequency must be selected, a 5 MHz probe provides the best versatility for visualizing the reproductive tract in swine. Other basic requirements for ultrasound equipment which will be used on commercial swine farms include being light weight and easy to handle, readily cleanable and disinfectable, long battery-life, and good durability. When using RTU for pregnancy determination, diagnosis is based upon a combination of the animal’s breeding records, the presence of embryonic fluid, and, depending upon gestational stage, fetal structures. If RTU is used as a diagnostic tool in assessing reproductive problems in an individual or a group of animals, sonographic evaluation of both the uterus and ovaries is performed. Tissues are delineated and assessed based upon their echogenicity, echotexture, and size. Uses of RTU in clinical practice may include assessment of delayed puberty, prolonged wean-to-estrus interval, absence of post-weaning estrus, herd disruptions in conception and farrowing rates, vulval discharge, peripartum and puerperal disorders. This review aims to provide an overview on principles and clinical uses of RTU with respect to application to address female reproductive performance issues in commercial swine operations. Full article

Due to lower farrowing rate and reduced litter size with frozen-thawed semen, over 90% of artificial insemination (AI) is conducted using liquid stored boar semen. Although substantial progress has been made towards optimizing the cryopreservation protocols for boar sperm, the influencing factors and underlying mechanisms related to cryoinjury and freeze tolerance of boar sperm remain largely unknown. In this study, we report the differential expression of mRNAs and miRNAs between fresh and frozen-thawed boar sperm using high-throughput RNA sequencing. Our results showed that 567 mRNAs and 135 miRNAs were differentially expressed (DE) in fresh and frozen-thawed boar sperm. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that the majority of DE mRNAs were enriched in environmental information processing such as cytokine-cytokine receptor interactions, PI3K-Akt signaling, cell adhesion, MAPK, and calcium signaling pathways. Moreover, the targets of DE miRNAs were enriched in significant GO terms such as cell process, protein binding, and response to stimuli. In conclusion, we speculate that DE mRNAs and miRNAs are heavily involved in boar sperm response to environment stimuli, apoptosis, and metabolic activities. The differences in expression also reflect the various structural and functional changes in sperm during cryopreservation. Full article