Pig Farms Research Articles

African Local Pig Genetic Resources in the Context of Climate Change Adaptation.

Africa is home to a wide diversity of locally adapted pig breeds whose genetic architecture offers important insights into livestock adaptation to climate change. However, the majority of these inherent traits have not been fully highlighted. This review presents an overview of the current state of African pig genetic resources, providing highlights on their population and production statistics, production system, population diversity indices, and genomic evidence underlying their evolutionary potential. The study results reveal an incomplete characterization of local pig genotypes across the continent. The characterized population, however, demonstrates moderate to high levels of genetic diversity, enough to support breeding and conservation programs. Owing to low genetic differentiation and limited evidence of distinct population structures, it appears that most local pig populations are strains within larger breeds. Genomic evidence has shown a higher number of selection signatures associated with various economically important traits, thus making them potential candidates for climate change adaptation. The reportedly early evidence of hybridization with wild suid groups further suggests untapped insights into disease resistance and resilience traits that need to be illuminated using higher-density markers. Nevertheless, gene introgression from commercial breeds is prevalent across Africa; thus, efforts to realize and utilize these traits must increase before they are permanently depleted.

Pathological characteristics of SRY-negative 38,XX-DSD pigs: A family case report

Disorders of sex development (DSD) are congenital conditions characterized by atypical development of chromosomes, gonads, or anatomical sex. XX-DSD pigs disrupt the production of high-quality breeding pigs and impede the advancement of the pig industry. However, the etiology of XX-DSD pigs remains unclear. Systematic reports on the genetic and pathological characteristics of prepubescent XX-DSD pigs in familial contexts are sparse. This study aimed to investigate the genetic and pathological features of one-month-old XX-DSD pigs within a familial context and to provide phenotypic information to elucidate the pathogenic mechanisms of XX-DSD pigs. The findings revealed that inbreeding within the XX-DSD family may contribute to the pathogenesis of XX-DSD pigs. All XX-DSD pigs in the family had a chromosomal sex of female and were male pseudohermaphrodites. The degree of masculinization of the reproductive organs varied among XX-DSD pigs, demonstrating phenotypic heterogeneity. HE staining showed that the testes of prepubescent XX-DSD pigs contained vesicles in the seminiferous tubules, with or without vestigial germ cells. Ultrastructural analyses indicated that sertoli cells, leydig cells and germ cells in the testes of XX-DSD pigs exhibited pathological damage, confirming impaired testicular function. Immunofluorescence staining revealed high expression of SRY-box transcription factor 9 (SOX9) in XX-DSD pig testicular tissues, while forkhead box L2 (FOXL2) was minimally expressed. Disordered secretion of reproductive hormones in prepubescent XX-DSD pigs indicated abnormal hypothalamic-pituitary-gonadal axis (HPGA) function. This study elucidates the genetic and pathological characteristics of prepubescent XX-DSD pigs in familial case, providing valuable insights for further exploration of the pathogenic mechanisms underlying XX-DSD.

An accessible and intuitive approach to 3D data modeling for morphometric surface evaluation in pig farming

The recording of pig surfaces allows for the estimation of growth-related body size dimensions from which the animals’ condition can be inferred. Furthermore, for purposes such as animal breeding, it is of particular interest to describe the shape variations within the population. Therefore, we built a Statistical Shape Model (SSM) that enables a quantitative and visual exploration of variation in size, form and posture in an intuitive way.We included 4315 images from 582animals with a body weight ranging from 50 to 140 kg. After data processing, i.e. the removal of data points corresponding to the head and tail, the 3D point clouds were reduced to an equal number of reference points. These reference points were arranged so that the pig surface could be reconstructed via Bézier surface patches. Then, Procrustes Analysis was performed to align the reference points from all shapes. A mean shape and its main modes of variation were derived, some of which were used to correct the posture of the animals.A linear regression for weight prediction resulted in a mean absolute error of 5.06 kg before and 2.84 kg after data processing. The median error of surface reconstruction was 2.5 mm taking eight surface patches with 45 reference points and 1.3 mm taking 32 surface patches with 153 reference points into account. The first six modes of variation from the SSM indicated differences in size and posture. Interestingly, regions prone to noise were also revealed.In conclusion, we present a novel approach that can be used to receive a compact number of corresponding data points, providing data that is easier and more efficient to handle while exposing shape-specific attributes. Our approach is helpful to visualize and compare shapes, including the collection of body size measurements as well as unsupervised and supervised clustering for more objective data-driven decision-making.

Aerobic granular sludge for swine wastewater treatment: Implications for antibiotic and antibiotic resistance gene elimination

Swine wastewater (SW) contains high levels of traditional pollutants, antibiotics, and antibiotic resistance genes (ARGs), necessitating effective elimination. Two parallel aerobic granular sludge (AGS) reactors, R1 and R2, were constructed and optimized for treating SW from two pig farms, identified as SW1 and SW2. R2 showed higher antibiotic removal efficiency, particularly in the removal of sulfonamides, while fluoroquinolones tended to adsorb onto the sludge. Process optimization by introducing an additional anoxic phase enhanced denitrification and reduced effluent ARG levels, also aiding in the improved removal of fluoroquinolones. The nitrite-oxidizing bacteria (NOB) Nitrospira accumulated after the treatment process, reaching 12.8 % in R1 and 14.1 % in R2, respectively. Mantel’s test revealed that pH, NH4+-N, and Mg significantly affected ARGs and microbial community. Sulfadiazine and sulfamethazine were found to significantly impact ARGs and the microbial communities. This study provides innovative insights into the application of AGS for the treatment of real SW.

Concurrent Ascaris infection modulates host immunity resulting in impaired control of Salmonella infection in pigs.

Ascaris is one of the most widespread helminth infections, leading to chronic morbidity in humans and considerable economic losses in pig farming. In addition, pigs are an important reservoir for the zoonotic salmonellosis, where pigs can serve as asymptomatic carriers. Here, we investigated the impact of an ongoing Ascaris infection on the immune response to Salmonella in pigs. We observed higher bacterial burdens in experimentally coinfected pigs compared to pigs infected with Salmonella alone. The impaired control of Salmonella in the coinfected pigs was associated with repressed interferon gamma responses in the small intestine and with the alternative activation of gut macrophages evident in elevated CD206 expression. Ascaris single and coinfection were associated with a rise of CD4-CD8α+FoxP3+ Treg in the lymph nodes draining the small intestine and liver. In addition, macrophages from coinfected pigs showed enhanced susceptibility to Salmonella infection in vitro and the Salmonella-induced monocytosis and tumor necrosis factor alpha production by myeloid cells was repressed in pigs coinfected with Ascaris. Hence, our data indicate that acute Ascaris infection modulates different immune effector functions with important consequences for the control of tissue-invasive coinfecting pathogens.IMPORTANCEIn experimentally infected pigs, we show that an ongoing infection with the parasitic worm Ascaris suum modulates host immunity, and coinfected pigs have higher Salmonella burdens compared to pigs infected with Salmonella alone. Both infections are widespread in pig production and the prevalence of Salmonella is high in endemic regions of human Ascariasis, indicating that this is a clinically meaningful coinfection. We observed the type 2/regulatory immune response to be induced during an Ascaris infection correlates with increased susceptibility of pigs to the concurrent bacterial infection.

Generation of an infectious cDNA clone for NADC30-like PRRSV.

The porcine reproductive and respiratory syndrome virus (PRRSV) is a highly significant infectious disease that poses a substantial threat to the global pig industry. In recent years, the NADC30-like strain has gradually emerged as prevalent in China, causing a profound impact on the country's pig farming industry. Therefore, it is important to conduct an in-depth study on the characteristics and gene functions of the NADC30-like strain. An infectious cDNA clone is an indispensable tool for investigating the functions of viral genes. In this current study, we successfully isolated a NADC30-like strain and constructed its full-length infectious cDNA clone. The utilization of this clone will facilitate our investigation into the viral replication, pathogenesis, and immune response associated with the PRRSV NADC30-like strain.

Effects of a veterinary functional music-based enrichment program on the psychophysiological responses of farm pigs

Intensification of swine production can predispose pigs to chronic stress, with adverse effects on the neuroendocrine and immune systems that can lead to health problems, poor welfare, and reduced production performance. Consequently, there is an interest in developing tools to prevent or eliminate chronic stress. Music is widely used as a therapeutic strategy for stress management in humans and may have similar benefits in non-human animals. This study evaluated the effects of a music-based auditory enrichment program in pigs from a multidimensional perspective by assessing psychophysiological responses. Two experimental groups of 20 pigs each were selected for the study: one enriched, exposed to a program of functional veterinary music designed for pigs, and a control group without auditory stimulation. Qualitative behavior assessment (QBA) and skin lesions indicative of agonistic behavior were used to evaluate the psychological determinants underlying the observed behaviors. Physiological assessment included hemograms, with the determination of the neutrophil:lymphocyte ratio and daily measurements of cortisol and salivary alpha-amylase levels. The results demonstrated a positive effect of a music-based auditory program on psychophysiological responses. Therefore, this strategy developed for environmental enrichment may be beneficial in reducing stress and contributing to the welfare and health of pigs under production conditions.

The Impact of Pig Futures on the Price Transmission in the Pig Industry Chain during Market Shocks

In recent years, frequent external emergencies have continuously impacted China’s pig industry chain. As the scale and standardization of pig farming in China have increasingly improved, pig futures have met the conditions for good operation and were listed for trading on the Dalian Commodity Exchange on 8 January 2021. To study the impact and influence of African swine fever, COVID-19, and the listing of pig futures on the price transmission mechanism at various stages of China’s pig industry, weekly price data from the pig industry from January 2015 to June 2023 were selected to construct an SV-TVP-VAR model for analysis. The empirical results showed that the shocks of African swine fever and COVID-19 caused price fluctuations at various stages of the pig industry chain, while price fluctuations significantly decreased after the listing of pig futures. Therefore, the introduction of pig futures effectively alleviated the price fluctuations at various stages of the pig industry chain following the shocks of African swine fever and COVID-19, and relevant policy recommendations are proposed accordingly.

Instance segmentation of pigs in infrared images based on INPC model

Conventional segmentation methods based on visible images in intensive pig farming face various challenges. Examples include color differences between pig breeds, background interference and lighting conditions. To overcome these issues, we designed the infrared pig cascade segmentation (INPC) model for the first time on infrared images. The model uses a cascade structure. Each stage utilizes higher resolution feature maps to better preserve fine details. It also solves the problem of poor segmentation of small objects due to low resolution of infrared images. At the same time, the model’s cross-guidance strategy enhances the interaction between bounding box regression and mask prediction. This reduces errors caused by interference like feces and urine. Additionally, a progressive mask branch refines mask prediction, improving segmentation in scenarios like imaging haze or pig adhesion. To facilitate model training and evaluation, we built the first large-scale standardized infrared pig dataset. Experimental results demonstrate that INPC outperforms mainstream segmentation models in terms of average precision (AP), except for AP0.5. Specifically, INPC achieves AP0.5, AP0.75, AP0.5:0.95, AP0.5:0.95s, and AP0.5:0.95l of 97.9%, 97.1%, 88.2%, 71.5%, and 90.1% respectively. Inference for a single image on a GPU takes only 0.197 s. Some datasets are available at https://github.com/HUBUwg96/INPC.

The Role of Wild Boar as Host of Japanese Encephalitis Virus in the Absence of Domestic Pigs.

Pigs are the most common amplifying hosts of the Japanese encephalitis virus (JEV). In 2016, four residents on Tsushima Island who did not own pig farms were diagnosed with JE. Therefore, a serosurvey was conducted to estimate the risk and seroprevalence of JEV after the outbreak. Sera collected from 560 Tsushima Island residents between January and September 2017 were tested for neutralizing antibodies against JEV strains JaGAr01 (genotype 3) and Muar (genotype 5). Sera collected from six wild boars between June and July 2022 were tested. The seroprevalence rates of neutralizing antibodies against JaGAr01 and Muar were 38.8% and 24.6%, respectively. High anti-JEV neutralizing antibody titers of ≥320 were identified in 16 residents, including 3 younger than 6 years with prior JEV vaccination, 2 in their 40s, and 11 older than 70. However, no anti-JEV-specific IgM was detected. Residents who engaged in outdoor activities had higher anti-JEV antibody titers. Sera from wild boars were negative for JEV RNA, but four of six samples contained neutralizing antibodies against JEV. Therefore, JEV transmission continues on Tsushima Island, even in the absence of pig farms, and wild boars might serve as the amplifying hosts.

INTENSITY OF GREENHOUSE GAS FORMATION DUE TO LIVESTOCK FARMING ACTIVITIES – AS AN ENVIRONMENTAL FACTOR

According to numerous expert assessments by international organizations and specialists, animal husbandry makes a significant negative contribution to global climate change due to the emission of greenhouse gases (GHG), which are formed at different stages of livestock production as a result of various chemical and biological processes in the body of animals and in livestock waste. The domestic animal husbandry is developing mainly due to the intensification of production in the industry, but traditional farming methods as well as small-scale production in the individual sector also take place. Since the use of various technologies in animal husbandry has different effects on the level of environmental pollution and GHG emissions, the aim of the research was to study the differences in the intensity of GHG gas formation by one animal reared with individual features of animal rearing technologies and business activities. The intensity of gas formation and emission of CH4 and N2O in typical farms for pork production and milk production by one animal reared was determined, analyzed and substantiated. A significant variation in this indicator was found depending on the individual economic and technological features of the studied farms. The average weighted annual intensity of CH4 emission from animal manure in pig farms varied within the range of 0.95–25.71, in cattle farm – 2.74; CH4 from intestinal fermentation of dairy cows – 110.8–148.4; N2O (direct) in pig farms – 0.0–0.106, in cattle farm – 0.229; N2O (indirect) in pig farms – 0.071–0.097, in cattle farm – 0.174. The emission intensity is characterized separately in each age and sex group of animals in the herd structure of farms and the average weighted emission intensity in pork producing farms depending on the season. Based on the research results, it is proposed to use the generalized average annual indicator of greenhouse gas emissions per one average weighted animal reared (kg/head/year) as an indicator of the environmental load of livestock farms on the environment, which will allow planning production volumes with minimal environmental risks in the context of climate change.

PIGS OF MEAT BREEDS IN UKRAINE AND THE NEED FOR THE REVIVAL OF PIG BREEDING

The article highlights the peculiarities of pork production in Ukraine, examines the productivity of domestic and foreign meat breeds of pigs in the dynamics of 2002–2022. It was found that the meat pork market in Ukraine developed intensively from 2002 to 2016, with a sharp reduction thereafter. The breeds of pigs in the meat direction of productivity include Durok, Landras, Pietrain, Poltavian Meat, Welsh, Ukrainian Meat and Red White-Beltid with some changes in the breed composition during 2002–2022. It was established that until 2005, the leaders in the meat pork production market were the Ukrainian and Poltavian Meat breeds, which were later supplanted by Landrace pigs. The population of the main sows of the investigated breeds was 7.8–9.3% of the total number of pigs, including 8.9% in 2022, which ensured the necessary reproduction of animals with some nuances regarding small populations. In 2022, the number of queens of the landrace breed will be 87.7–98.8% higher than the number of the rest of the studied breeds. Sows of meat breeds, which were bred in breeding farms during 2002–2022, are characterized by significant variability of multifertility, and the difference in the trait within one breed quite often exceeded the interbreed difference. The variability of the best indicators of the age of pigs reaching a live weight of 100 kg in the process of their cultivation in representatives of the Durok breed during the years 2002–2022 was 164–178 days, Landras 148–183 days, Pietrain 150–154 days, Poltavian Meat 179–198 days, Welsh 156–187 days, Ukrainian Meat 174–187 days and Red White-Beltid 181–207 days. The highest indicators of average daily gains were among pigs of the Durok breed, which varied between 658–810 g, Landras 612–860 g, Pietrain 520–890 g, Poltavian Meat 574–735 g, Welsh 344–628 g, Ukrainian butchers 435–768 g and Red White-Beltid 470–635 g. It has been proven that Durok pigs in the best breeding herds had lard thickness at the level of 13–16 mm, Landras 10–12 mm, Pietrain 7–9 mm, Poltavian Meat 21–23 mm, Welsh 12–16 mm, Ukrainian Meat 16–20 mm and Red White-Beltid 22–23 mm. On the example of the genealogical structure of pigs of the Landrace and Pietrain breeds, as well as the market for the sale of breeding offspring and semen, the conduct of purebred breeding in subjects of the breeding business in the pig industry of Ukraine is questioned. In order to revive Ukrainian pig farming and bring order to breeding pig breeding, it is recommended to take into account the requirements for the functioning of the pig breeding industry in the countries of the European Union.

Fertility after photodynamic inactivation of bacteria in extended boar semen.

Antimicrobial resistance is an increasing challenge in semen preservation of breeding animals, especially in the porcine species. Bacteria are a natural component of semen, and their growth should be inhibited to protect sperm fertilizing capacity and the female's health. In pig breeding, where semen is routinely stored at 17°C in the liquid state, alternatives to conventional antibiotics are urgently needed. Photodynamic inactivation (PDI) of bacteria is a well-established tool in medicine and the food industry but this technology has not been widely adopted in semen preservation. The specific challenge in this setting is to selectively inactivate bacteria while maintaining sperm integrity and functionality. The aim of this study was to test the principle of PDI in liquid stored boar semen using the photosensitizer 5,10,15,20-tetrakis(N-methyl-4-pyridyl)-21H,23H-porphine (TMPyP) and a white light LED-setup. In the first step, photophysical experiments comprising singlet oxygen phosphorescence kinetics of TMPyP and determination of the photosensitizer triplet time revealed a sufficiently high production of reactive singlet oxygen in the Androstar Premium semen extender, whereas seminal plasma acted as strong quencher. In vitro experiments with extended boar semen showed that the established PDI protocol preserves sperm motility, membrane integrity, DNA integrity, and mitochondrial activity while efficiently reducing the bacteria below the detection limit. A proof-of-concept insemination study confirmed the in vivo fertility of semen after photodynamic treatment. In conclusion, using the PDI approach, an innovative tool was established that efficiently controls bacteria growth in extended boar and maintains sperm fertility. This could be a promising contribution to the One Health concept with the potential to reduce antimicrobial resistance in animal husbandry.

Isolation of Limosilactobacillus mucosae G01 with inhibitory effects on porcine epidemic diarrhea virus in vitro from Bama pig gastroenteritis.

Porcine epidemic diarrhea virus (PEDV) is responsible for causing fatal watery diarrhea in piglets, resulting in significant economic losses within the pig farming industry. Although vaccination is currently employed as a preventive measure, certain vaccines do not provide complete protection against PEDV field strains. Probiotics present a promising alternative due to their ability to regulate intestinal flora, enhance host immunity, and improve resistance against pathogenic microorganisms. We isolated six lactic acid bacteria (LAB) from the fecal microorganisms of Bama pigs, compared to Limosilactobacillus mucosae DSM13345 of the same genus in which Limosilactobacillus mucosae G01 (L. mucosae G01) proved to have a potent anti-PEDV effect. In a comprehensive manner, L. mucosae G01 significantly augmented the phosphorylation of IRF3 in IPEC-J2 cells, resulting in the induction of interferons (IFN α, IFN β, IFN λ1, and IFN λ3) and subsequent upregulation of interferon-stimulated genes (ISGs) (MX1, MX2, OAS1, and ZAP) in a dose-dependent fashion, consequently leading to the mitigation of PEDV replication. These findings underscore the promising prospects of L. mucosae G01 as a naturally derived substitute for combating PEDV and other enteric coronavirus infections.

INFLUENCE OF THE BREED AND BREEDING METHODS OF PIGS ON THEIR REPRODUCTIVE QUALITIES AND GROWTH OF SUCKLING PIGLETS

The purpose of this article is to study the dependence of the reproductive productivity of sows of English origin and the intensity of growth of their offspring on the direction of their selection for purebred (internally linear) breeding, crossing and hybridization and the influence of breed and breeding methods on their manifestation, as well as the degree of phenotypic dominance under direct and reverse crossing of parent breeds. It was established that the sows of the parental synthetic line were inferior to their counterparts of the maternal genotypes in terms of fertility, litter weight of piglets at birth, number of piglets at weaning, had a higher proportion of non-viable piglets at farrowing, but showed higher fertility, average daily and absolute gains, average weight of one piglet at weaning and better preservation of piglets until weaning. It was proved that under the conditions of hybridization, domestic sows surpassed animals of the original maternal form only in terms of average daily growth, while animals of the parental form they prevailed in terms of multifertility, number of piglets at weaning, weight of the nest at birth and at weaning and were inferior to them in terms of high fertility, growth intensity, mass one piglet at weaning and preservation. It was found that when two mother breeds were crossed, the effect of phenotypic dominance appeared in almost all indicators of reproductive performance, and its level depended on the combination of parent breeds. It was proved that the breed factor had a probable influence on the number of piglets at weaning and the weight of the nest of weaned piglets. The method of pig breeding likely influenced the weight of one piglet at weaning, the weight of their litter during this period, and the number of piglets at weaning. The interaction of these two factors had an impact on the survival of the herd, on the number of piglets and the weight of the nest of piglets at weaning.

BREEDING ACHIEVEMENTS OF UKRAINE (PAST, PRESENT): BREEDS, TYPES AND LINES OF AGRICULTURAL ANIMALS

The purpose of the study was to establish chronologically breeding achievements in livestock breeding of Ukraine with the help of the relevant Register. To analyze the dynamics of the number of breeding animals, the State Register of Breeding Subjects in Livestock Breeding for the period 2002 ... 2022 was used. The genealogical structure of the six studied breeds of dairy cattle includes 10 interbreed and 11 local types, 47 local and 38 genealogical lines and about 244 families. Beef cattle are represented by four approved breeds, 4 interbreed and 2 local types, 32 lines and 172 families. The pedigree pig breeding of Ukraine includes seven domestic breeds with three interbreed types, 11 local types, 95 lines and 159 families. In the fields of sheep breeding and horse breeding, five and two breeds were created, respectively, and their genealogical structure was formed from 11 interbreed types and 28 families in sheep breeding and 15 lineages and related groups and 25 families in horse breeding. One breed and two crosses (10 lines) of laying hens, one cross (two lines and eight microlines) of turkeys and four breed groups of ducks represent poultry breeding.

Virulence and Antimicrobial Resistance Characterization of Glaesserella parasuis Isolates Recovered from Spanish Swine Farms.

Glaesserella (Haemophilus) parasuis, the causative agent of Glässer's disease, is present in most pig farms as an early colonizer of the upper respiratory tract. It exhibits remarkable variability in virulence and antimicrobial resistance (AMR), with virulent strains capable of inducing respiratory or systemic disease. This study aimed to characterize the virulence and the AMR profiles in 65 G. parasuis isolates recovered from Spanish swine farms. Virulence was assessed using multiplex leader sequence (LS)-PCR targeting vtaA genes, with all isolates identified as clinical (presumed virulent). Pathotyping based on ten pangenome genes revealed the virulent HPS_22970 as the most frequent (83.1%). Diverse pathotype profiles were observed, with 29 unique gene combinations and two isolates carrying only potentially non-virulent pangenome genes. AMR phenotyping showed widespread resistance, with 63.3% classified as multidrug resistant, and high resistance to clindamycin (98.3%) and tylosin (93.3%). A very strong association was found between certain pathotype genes and AMR phenotypes, notably between the virulent HPS_22970 and tetracycline resistance (p < 0.001; Φ = 0.58). This study reveals the wide diversity and complexity of G. parasuis pathogenicity and AMR phenotype, emphasizing the need for the targeted characterization of clinical isolates to ensure appropriate antimicrobial treatments and the implementation of prophylactic measures against virulent strains.

Convergent dwarfism consequences of minipigs under independent artificial selections

BackgroundCurrently, diverse minipigs have acquired a common dwarfism phenotype through independent artificial selections. Characterizing the population and genetic diversity in minipigs is important to unveil genetic mechanisms regulating their body sizes and effects of independent artificial selections on those genetic mechanisms. However, full understanding for the genetic mechanisms and phenotypic consequences in minipigs still lag behind.ResultsHere, using whole genome sequencing data of 41 pig breeds, including eight minipigs, we identified a large genomic diversity in a minipig population compared to other pig populations in terms of population structure, demographic signatures, and selective signatures. Selective signatures reveal diverse biological mechanisms related to body size in minipigs. We also found evidence for neural development mechanism as a minipig-specific body size regulator. Interestingly, selection signatures within those mechanisms containing neural development are also highly different among minipig breeds. Despite those large genetic variances, PLAG1, CHM, and ESR1 are candidate key genes regulating body size which experience different differentiation directions in different pig populations.ConclusionsThese findings present large variances of genetic structures, demographic signatures, and selective signatures in the minipig population. They also highlight how different artificial selections with large genomic diversity have shaped the convergent dwarfism.

Влияние теплового стресса на оплодотворяемость и многоплодие свиноматок

Abstract. The study of the effect of heat stress on the reproductive parameters of pigs is an urgent problem all over the world. Knowing the degree of influence of heat stress on pigs of different breeds will allow you to choose economically sound solutions to this problem in specific conditions. The propose is to study the effect of heat stress on some indicators of reproduction of sows of different breeds (large white, landrace, duroc, MAXGRO). Methods. The study was conducted on a large pig breeding complex. The material for the analysis was data on changes in air temperature in the breeding farm in the period from June to August (13 weeks) and data on the fertilization and duration of pregnancy of sows fertilized during this period and the size of the offspring obtained from them. Scientific novelty. For the first time, a comparative analysis of the effect of heat stress on fertilization, duration of pregnancy and the size of the offspring of sows of four breeds – large white, landrace, duroc, MAXGRO – was carried out on a wide population of pigs. Different sensitivity of sows to heat stress was revealed. Results. From the 4th to the 6th week of the experiment, the sows were in a state of increasing heat stress – the average daily temperature during this period increased to 27.68 ± 1.36 °C. The negative effect of hyperthermia on fertilization was recorded with a delay of 1–3 weeks, depending on the breed. The most sensitive to heat stress were sows of the duroc breed – fertilization decreased by 25.00 % compared to the pre-stress period, the least – sows of the large white breed – fertilization decreased by 9.82 %. The duration of pregnancy was not affected by heat stress. As well as fertilization, heat stress had a negative effect on the size of the litter. The most sensitive were sows of duroc and MAXGRO breeds – the litter size decreased by 3.77 and 3.61 heads compared to the pre-stress period, the least – sows of the large white breed, the size of the litter decreased by 0.38 heads. duroc sows are the most sensitive to heat stress, then, according to sensitivity reduction, MAXGRO, landrace and large white.

Морфофункциональное состояние органов иммунной системы у поросят-гипотрофиков в ранний неонатальный период

Abstract. The purpose of the study was to study the state of the immune system organs in hypotrophic piglets in the early neonatal period in an industrial pig breeding complex. Methods. The experiment was conducted in 2023 in a large industrial pig farm in the Voronezh region on piglets of the wounded neonatal period received from sows 3-4 farrowing. The sows were kept at optimal microclimate parameters, taking into account their physiological state, and fed with SK-1 nutritionally balanced feed. At the initial stage of the experiment, the piglets obtained during farrowing underwent clinical examination and weighing. Animals under 800 g are counted as hypotrophic piglets (n = 30), animals over 800 g are normotrophic, respectively (n =30). After the groups were formed, animals were forced to be slaughtered before taking colostrum (n =5) and biological material was taken from each group (thymus, lymph nodes (inguinal), spleen for immunohistochemical studies. Results. The level of mitotic activity in the thymus of normotrophic piglets was 9.4 % higher (p &lt; 0.05) than in piglets with body weight deficiency. In the spleen, the level of mitotic activity had no significant differences and was approximately the same in all animals participating in the experiment. In lymph nodes, the mitotic activity of cells in normotrophics was 12.7 % higher (p &lt; 0.05). A study of positively expressed CD-3 cells in the spleen revealed significant differences, so, in normotrophic piglets, the number of cells positively stained with this marker was significantly higher than in piglets with a body weight deficiency by 10.2 % (p &lt; 0.05). The number of CD-3 cells in the thymus differed by 5.6 %, and in the lymph nodes by 2.4 % between the groups, but there were no significant differences. The cellular expression of “immature” forms of B lymphocytes (PAX-5) in the lymph nodes of normotrophics was significantly higher by 12.9 % (p &lt; 0.05) compared with hypotrophic piglets. The scientific novelty lies in the fact that for the first time a comprehensive immunohistochemical study of the organs of the immune system of piglets in the early neonatal period was carried out using monoclanal antibodies CD-3, Ki-67 and PAX-5. As a result of the experiment, it was revealed that piglets with body weight deficiency have a “depression” of the immune system, which manifests itself in hypoplasia of T-lymphocytes in the spleen, “maturing” B-lymphocytes in the lymph nodes and low mitotic potential in the thymus and lymph nodes.