Pig Weight Research Articles

Minimally Invasive Transthoracic Intramyocardial Cellular Transplantation Under Echocardiographic Guidance for Myocardial Impairment

Abstract Objective: To explore the approach of minimally invasive transthoracic intramyocardial cellular transplantation under echocardiographic guidance to promote ischemic myocardial repair in a preclinical big-animal study. Methods: Female Guangxi Bama miniature pigs (weight: 25–30 kg) were randomly allocated into the sham group, untreated myocardial infarction (MI) group (MI group), the MI and surgical intramyocardial injection (SIM) group (MI-SIM group), and the MI and transthoracic echocardiography-guided percutaneous intramyocardial injection (TTEPIM) group (MI-TTEPIM group) (n = 4 each) using a lottery method. A swine MI model was established in the 3 groups excluding the sham group, and human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CM) labeled with the herpes simplex virus type-1 thymidine kinase reporter gene (hiPS-CMTK+) were transplanted by SIM in MI-SIM group and TTEPIM in MI-TTEPIM group. The operation time, postoperative recovery time of animals and volume of blood loss were collected for comparison between MI-SIM group and MI-TTEPIM group. 9-(4-[18F] fluoro-3-(hydroxymethyl) butyl) guanine positron emission tomography/computed tomography imaging was performed to track the hiPS-CMTK+ in vivo. Cardiac function and morphology were evaluated by echocardiography. Results: The operation time and postoperative recovery time of MI-TTEPIM group were significantly shorter than those of MI-SIM group ((28.3 ± 3.6) min vs. (97.0 ± 6.7) min, P < 0.001; (1.3 ± 0.3) d vs. (7.5 ± 0.9) d, P < 0.001). MI-TTEPIM also showed significantly lesser volume of blood loss during cell transplantation than MI-SIM group ((4.3 ± 0.8) mL vs. (47.0 ± 4.1) mL, P < 0.001). The transplanted cells could be traced more accurately in vivo in MI-TTEPIM than in MI-SIM. The circumferential strain of intervention region in the MI-TTEPIM group (–25.07% ± 0.27%) was significantly higher than that of the MI-SIM (–20.39% ± 0.67%) and MI groups (–19.68% ± 0.67%), respectively (P < 0.01). Conclusion: A minimally invasive TTEPIM protocol with stem cells for treating the ischemic myocardium was established in this study. Transplantation of hiPS-CMTK+ with this method could promote the recovery of the circumferential strain of the ischemic myocardium. The findings of this study lay a foundation for the clinical transformation of this auxiliary means of treatment in the future.

A Review of Visual Estimation Research on Live Pig Weight

The weight of live pigs is directly related to their health, nutrition management, disease prevention and control, and the overall economic benefits to livestock enterprises. Direct weighing can induce stress responses in pigs, leading to decreased productivity. Therefore, modern livestock industries are increasingly turning to non-contact techniques for estimating pig weight, such as automated monitoring systems based on computer vision. These technologies provide continuous, real-time weight-monitoring data without disrupting the pigs’ normal activities or causing stress, thereby enhancing breeding efficiency and management levels. Two methods of pig weight estimation based on image and point cloud data are comprehensively analyzed in this paper. We first analyze the advantages and disadvantages of the two methods and then discuss the main problems and challenges in the field of pig weight estimation technology. Finally, we predict the key research areas and development directions in the future.

CD4+ but not CD8+ T cells are required for protection against severe guinea pig cytomegalovirus infections.

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus and the leading cause of infectious disease related birth defects worldwide. How the immune response modulates the risk of intrauterine transmission of HCMV after maternal infection remains poorly understood. Maternal T cells likely play a critical role in preventing infection at the maternal-fetal interface and limiting spread across the placenta, but concerns exist that immune responses to infection may also cause placental dysfunction and adverse pregnancy outcomes. This study investigated the role of CD4+ and CD8+ T cells in a guinea pig model of primary cytomegalovirus infection. Monoclonal antibodies specific to guinea pig CD4 and CD8 were used to deplete T cells in non-pregnant and in pregnant guinea pigs after mid-gestation. CD4+ T cell depletion increased the severity of illness, caused significantly elevated viral loads, and increased the rate of congenital guinea pig cytomegalovirus (GPCMV) infection relative to animals treated with control antibody. CD8+ T cell depletion was comparably well tolerated and did not significantly affect the weight of infected guinea pigs or viral loads in their blood or tissue. However, significantly more viral genomes and transcripts were detected in the placenta and decidua of CD8+ T cell depleted dams post-infection. This study corroborates earlier findings made in nonhuman primates that maternal CD4+ T cells play a critical role in limiting the severity of primary CMV infection during pregnancy while also revealing that other innate and adaptive immune responses can compensate for an absent CD8+ T cell response in α-CD8-treated guinea pigs.

Gender-Specific DNA Methylation Profiles Associated with Adult Weight in Hezuo Pigs

The Hezuo pig, an important native Tibetan breed in China, exhibits differences in adult body weight, with females typically heavier than males. The underlying mechanisms for this disparity remain unclear. DNA methylation changes are known to influence animal growth and development and regulate Hezuo pig growth by altering gene expression related to these processes, thus differentially affecting adult body weight between genders. This study conducted DNA methylation analysis and expression profiling using pituitary tissues from male and female Hezuo pigs at 3 and 8 months old (M3M, M3F, M8M, and M8F). In total 346, 795, 371, and 839 differentially methylated genes (DMGs) were identified in the M3M vs. M3F, M3F vs. M8F, M3M vs. M8M, and M8M vs. M8F groups, respectively. The comparative analysis of differentially methylated regions (DMRs) genes and DEGs (differentially expressed regions) revealed that key genes involved in growth, hormone secretion, and the hypothalamic-pituitary-gonadal axis are primarily enriched in signaling pathways such as PI3K-Akt, Hippo, and adrenergic. Further analysis combining methylation and transcriptomics identified five candidate methylated genes (CCL2, MYL2, GST, CTSH, and MCH) linked to adult body weight in Hezuo pigs. Additionally, the correlation analysis suggested that these genes influence growth and development in boars and sows by regulating the secretion and synthesis of related hormones, leading to heavier weights in females. In conclusion, variations in adult body weight between male and female pigs may stem from the impact of DNA methylation on gene expression related to growth and development. These findings offer new insights into the regulatory mechanisms of DNA methylation during weight gain in Hezuo pigs.

A genome-wide association study reveals candidate genes and regulatory regions associated with birth weight in pigs.

Piglet birth weight is associated with preweaning survival, and its related traits have been included in the breeding program. Thus, understanding its genetic basis is essential. This study identified four birth weight-associated genomic regions on chromosomes 2, 4, 5, and 7 through genome-wide association study analysis in 7286 pigs from three different pure breeds using the FarmCPU model. The genetic and phenotypic variance explained by the four candidate regions is 8.42% and 1.85%, respectively. Twenty-eight candidate genes were detected, of which APPL2, TGFBI, MACROH2A1, and SEC22B have been reported to affect body growth or development. In addition, 21 H3K4me3-enriched peaks overlapped with the birth weight-associated genomic regions were identified by integrating the genome-wide association study results with our previous ChIP-seq and RNA-seq data generated in the pig placenta, a fetal organ relevant to birth weight, and three of the regulatory regions influence TGFBI, MACROH2A1, and SEC22B expression. This study provides new insights into understanding the mechanisms for birth weight. Further investigating the variants in the regulatory regions would help identify the functional variants for birth weight in pigs.

Dependence of the hindgut disappearance of phosphorus in pigs on the quantity of phosphorus entering the hindgut based on a Meta-analysis

The objectives of the current study were to compare the difference between standardized ileal digestibility (SID) and standardized total tract digestibility (STTD) of phosphorus (P) in pigs using published data and investigate the factors that affect the hindgut disappearance of P in pigs. A total of 156 observations from 32 experiments that determined the apparent ileal digestibility and total tract digestibility of P in pigs were collected. SID and STTD of P were calculated by accounting for basal endogenous losses of P. Standardized hindgut disappearance (SHD) of P was determined by subtracting the STTD of P from the SID of P. The chi-square test was performed to investigate the association between SHD of P and categorical variables, including the use of phytase, the use of inorganic P sources, the use of corn-soybean meal-based diets, and body weight (BW) of pigs. To determine the effects of the SID of P on the SHD of P, a linear equation for the SHD of P was developed using the SID of P as an independent variable. The BW of pigs ranged from 10.0 to 104.8 kg and the SHD of P ranged from –22.8% to 39.8%. The STTD of P was greater than the SID of P (47.1% vs. 49.7%; P = 0.019). Based on the chi-square analysis, the supplementation of inorganic P sources tended to result in a higher occurrence of a positive value for the SHD of P (P = 0.079). In addition, the occurrence of a positive value in the SHD of P was lower when the BW of pigs was below 30 kg. However, as the BW of pigs increased, the occurrence of a positive value in the SHD of P increased (P = 0.061). A regression analysis of the SHD of P against the SID of P in pigs indicated that the SHD of P decreased as the SID of P increased in pigs (r2 = 0.17; P < 0.001). In conclusion, the STTD of P is greater than the SID of P in pigs, and the SHD of P depends on the diet composition, the amount of P entering the large intestine, and the BW of the pigs.

Prediction models for phosphorus excretion of pigs.

The present study aimed to measure fecal and urinary phosphorus (P) excretion from pigs and to develop prediction models for P excretion of pigs. A total of 96 values for P excretions were obtained from pigs of 15 to 93 kg body weight (BW) fed 12 diets in four experiments and were used to develop the prediction models. All experimental diets contained exogenous phytase at 500 phytase units per kg. Body weight of pigs and dietary P concentrations were used as independent variables in the prediction models. The BW, feed intake, and P intake were positively correlated with total (fecal plus urinary) P excretions (r = 0.80, 0.91, and 0.94, respectively; p<0.001). The models for estimating P excretion were: fecal P excretion (g/d) = -0.654-0.000618×BW2+0.273×BW ×dietary P concentration (R2 = 0.83; p<0.001); urinary P excretion (g/d) = 0.045+ 0.00781×BW×dietary P concentration (R2 = 0.15; p<0.001); total P excretion (g/d) = -0.598-0.000613×BW2+0.280×BW×dietary P concentration (R2 = 0.86; p<0.001) where the BW of pigs and dietary P concentration are expressed as kg and % (as-fed basis), respectively. Based on the developed prediction models, the estimated annual fecal, urinary, and total P excretion for a market pig was 1.24, 0.09, and 1.33 kg/yr, respectively. The P excretions in market pigs can be estimated using BW of pigs and dietary P concentration. In the present model, a market pig excretes 1.24 kg of fecal P and 0.09 kg of urinary P per year.

PSVI-29 Effect of pig weight and exogenous enzyme supplementation on ileal endogenous amino acid losses and standardized ileal amino acid digestibility of soybean meal produced from Kentucky-grown soybeans

Abstract There is increasing interest in using locally sourced soybeans and soybean meal. Ileal amino acid digestibility (IAAD) of soybean meal from Kentucky-grown soybeans was evaluated in 25- and 50-kg cannulated pigs. The experiment used sixteen pigs in a randomized complete block design consisting of four treatments with 4 pigs per treatment. This was repeated in time resulting in eight replicates per treatment for both body weight (BW)groups. After cannulation at about 20 kg BW, all pigs were allowed to recover from the surgery and were fed a corn-SBM-based diet that met all nutrient and energy requirements. The experimental diets consisted of two nitrogen-free diets [NFD] with or without exogenous enzyme supplementation (phytase and a combination of phytase and carbohydrase enzymes) and two semi-purified diets containing soybean meal from Kentucky-grown soybeans as the only source of protein with or without exogenous enzyme supplementation. Each diet was fed for 7 consecutive d with 10-h ileal digesta collection on d 6 and 7. The same diets were fed to the same set of pigs at about 50 kg BW. Data were analyzed as a factorial arrangement of treatments (BW x diet) for ileal endogenous amino acid losses (IEAAL), apparent IAAD and standardized IAAD (SIAAD). Data from the NFD were used to determine the SIAAD from the AIAAD values. Exogenous enzyme supplementation increased (P &amp;lt; 0.05) IEAAL except for Gly and Pro while samples collected during phase 2 had greater (P &amp;lt; 0.05) IEAAL (10 amino acids). Pig BW did not influence IEAAL. Enzyme supplementation did not increase AIAAD except for Arg, Ala, Gly, N, and total AA while apparent ileal N, Met, Thr, and Val digestibility was greater (P &amp;lt; 0.05) in 50 kg pigs. Interactions between BW and diets showed that 50 kg pigs fed the SBM diet containing enzyme supplementation had greater (P &amp;lt; 0.05) N, Arg, and total AA digestibility compared with 50 kg pigs without enzyme supplementation. Digestibility of Val and Asp was greater (P &amp;lt; 0.05) in samples collected during phase 2. After correction for basal IEAAL, 50 kg pigs had greater (P &amp;lt; 0.05) SIAAD values for 12 of the AA analyzed while exogenous enzyme supplementation resulted in greater (P &amp;lt; 0.05) SIAAD for 9 of the AA analyzed. The SIAAD values for four AA (His, Phe, Val, and Asp) were greater (P &amp;lt; 0.05) for samples collected in phase 2. Results from this study showed that exogenous enzyme supplementation increased IEAAL and that IAAD of SBM produced from Kentucky-cultivated soybeans was high and that exogenous enzyme supplementation improved the SIAAD values of several amino acids. The IAAD values of SBM produced from soybeans cultivated in KY was high and are similar to values reported in the literature.

Effects of Dietary Supplementation of Quillaja Saponin or Phytase on the Growth Performance, Nutrient Digestibility, Faecal Gas Emissions, and Carcass Grade in Growing-Finishing Pigs.

This experiment aimed to evaluate the effects of low doses of Quillaja saponin (QS) or phytase (PHY) on growth performance, nutrient digestibility, faecal gas emissions, and carcass grade in growing-finishing pigs. A total of 72 pigs (Landrace × Yorkshire × Duroc), each weighing 25.82 ± 1.68 kg, were selected and randomly assigned to three treatment groups. Each group had six replicates, with four pigs per pen, and the allocation was based on the four initial body weight and sex of the pigs. They were randomly divided into the following three diet groups: the basal diet as a control (CON) group, the basal diet + 0.02% PHY; and the basal diet + 0.01% QS. The experiment period lasted for 110 days. The results of adding 0.01% QS to the basal diet of pigs show that it can significantly increase the body weight (BW) of growing-finishing pigs on the 110th day (p < 0.05). QS can significantly increase the average daily weight gain (ADG) on Days 80-110 of the experiment (p < 0.05). QS can significantly increase the total average daily weight gain (TADG) of growing-finishing pigs during the entire experimental period (p < 0.05) and has a tendency to improve the average daily feed intake and feed conversion rate during the entire experimental period. However, QS has no significant effect on pig nutrient digestibility and carcass grade. In addition, we also found that QS has a tendency to reduce carbon dioxide emissions. However, adding 0.02% PHY to the basal diet of growing-finishing pigs can only increase the TADG during the entire experimental period. Throughout the experiment, adding PHY to the diet had no significant impact on the nutrient digestibility, faecal gas emissions, and carcass grade of growing-finishing pigs. In summary, adding QS to feed can significantly improve the growth performance of growing-finishing pigs, and has a tendency to improve faecal gas emissions. PHY can only improve the growth performance of growing-finishing pigs.

Monocular Visual Pig Weight Estimation Method Based on the EfficientVit-C Model

The meat industry is closely related to people’s daily lives and health, and with the growing global population and increasing demand for meat, the development of efficient pig farming technology is particularly important. However, China’s pig industry still faces multiple challenges, such as high labor costs, high biosecurity risks, and low production efficiency. Therefore, there is an urgent need to develop a fast, accurate, and non-invasive method to estimate pig body data to increase production efficiency, enhance biosecurity measures, and improve pig health. This study proposes EfficientVit-C model for image segmentation and cascade several models to estimate the weight of pigs. The EfficientVit-C network uses a cascading group attention module and improves computational efficiency through parameter redistribution and structured pruning. This method uses only one camera for weight estimation, reducing equipment costs and maintenance expenses. The results show that the improved EfficientVit-C model can segment pigs accurately and efficiently the mAP50 curve convergence is 98.2%, the recall is 92.6%, and the precision is 96.5%. The accuracy of pig weight estimation is 100 kg +/− 3.11 kg. On the Jetson Orin NX platform, the average time to complete image segmentation for each 640*480 resolution image was 4.1 ms, and the average time required to complete pig weight estimation was 31 ms. The results show that this method can quickly and accurately estimate the weight of pigs and provide guidance for the subsequent weight evaluation procedures of pigs.

Unraveling the impact of hyperleptinemia on female reproduction: insights from transgenic pig model

BackgroundInfertility is a growing global health concern affecting millions of couples worldwide. Among several factors, an extreme body weight adversely affects reproductive functions. Leptin is a well-known adipokine that serves as an endocrine signal between adiposity and fertility. However, the exact mechanisms underlying the effects of high leptin level on female reproduction remain unclear.MethodsTransgenic pigs overexpressing leptin (♀) were produced by backcrossing and screened for leptin overexpression. The growth curve, fat deposition, reproductive performance, apoptosis, serum hormones and cholesterol production, RNA sequencing, and single-nucleus RNA sequencing (snRNA-seq) of the leptin-overexpressing pigs and wild-type group were evaluated.ResultsTransgenic pigs overexpressing leptin (♀) were obtained, which exhibited significantly reduced body weight, body size, and back fat thickness. These pigs manifested a late onset of puberty (330 ± 54.3 vs. 155 ± 14.7 days), irregular estrous behavior characterized by increased inter-estrous interval (29.2 ± 0 vs. 21.3 ± 0.7 days), and more number of matings until pregnancy (at least 3 times). This reproductive impairment in leptin pigs was related to hormonal imbalances characterized by increased levels of FSH, LH, prolactin, E2, P4, and TSH, altered steroidogenesis such as increased levels of serum cholesterol esters along with steroidogenic markers (StAR, CYP19A), and ovarian dysfunctions manifested by neutrophilic infiltration and low expression of caspase-3 positive cells in the ovaries. Moreover, bulk RNA sequencing of the ovaries also revealed neutrophilic infiltration followed by upregulation of inflammation-related genes. Furthermore, snRNA-seq reflected that leptin overexpression triggered immune response, suppressed follicle development and luteinization, resulting in metabolic dysfunction and hormone imbalance in the ovary.ConclusionsLow body weight in leptin overexpressing pigs adversely affects the reproductive performance, causing delayed puberty, irregular estrous cycles, and reduced breeding efficiency. This is linked to metabolic imbalances, an increased immune response, and altered ovarian functions. This study provides a theoretical basis for the complex mechanisms underlying leptin, and infertility by employing leptin-overexpressing female pigs.

New management grading for pig farms: management grading system using pig carcass weight, back fat thickness and k-means algorithm.

This study categorized farm management levels to improve the productivity and uniformity of pork from pigs shipped from farms. A total of 48,298 pigs were grouped (A, B, C, D group) using the k-means algorithm, carcass weight and backfat thickness. The results of the grouping were used to classify farm management grades (A, B, C, D grade). The proportion of primal cuts in pigs, according to the new classification method, increased from group A to group D for shoulder blade, shoulder picnic, and ham, but decreased for loin and belly. In the regression analysis of the five primal cuts (shoulder blade, shoulder picnic, loin, belly, and ham) production (kg) for each group, all regression equations showed low errors (MAE<0.7), indicating that the model can predict the production of primal cuts by group. As the farm management grade decreased, the proportion of pigs in the group with large differences from the mean of carcass weight and backfat thickness of the whole pig increased. The results of this study confirmed the differences in primal cut traits by pig grouping and created a method to classify farms who ship non-uniform pigs. This is expected to provide indicators for improvement and supplementation to farms that ship uneven pigs, helping to enhance the production of standardized pigs at the farm level.

Pig Weight Estimation Method Based on a Framework Combining Mask R-CNN and Ensemble Regression Model.

Using computer vision technology to estimate pig live weight is an important method to realize pig welfare. But there are two key issues that affect pigs' weight estimation: one is the uneven illumination, which leads to unclear contour extraction of pigs, and the other is the bending of the pig body, which leads to incorrect pig body information. For the first one, Mask R-CNN was used to extract the contour of the pig, and the obtained mask image was converted into a binary image from which we were able to obtain a more accurate contour image. For the second one, the body length, hip width and the distance from the camera to the pig back were corrected by XGBoost and actual measured information. Then we analyzed the rationality of the extracted features. Three feature combination strategies were used to predict pig weight. In total, 1505 back images of 39 pigs obtained using Azure kinect DK were used in the numerical experiments. The highest prediction accuracy is XGBoost, with an MAE of 0.389, RMSE of 0.576, MAPE of 0.318% and R2 of 0.995. We also recommend using the Mask R-CNN + RFR method because it has fairly high precision in each strategy. The experimental results show that our proposed method has excellent performance in live weight estimation of pigs.

Infl uence of biologically active additive on meat productivity of pigs

In order to improve the digestibility and assimilation of nutrients in feed by animals, biologically active additives have recently been used in practice. The purpose of the research was to study the infl uence of a biologically active additive on the meat productivity of pigs. The research was carried out at the Agrofi rma Ariant LLC in the Emanzhelinsky district one of the largest pig-breeding complexes in the Chelyabinsk region for the production of pork on an industrial basis. The data on the use of the probiotic Bifi dumbacterin in the diet of fattening pigs have been presented in the article. The probiotic feed additive was given to animals in the amount of 0.05 and 0.10 g/head/day. It was found that the absolute gain in live weight of young pigs in the control group during the experimental period was 69.60 kg, in the 1st experimental group it was 74.16 kg, which was by 4.56 kg more, and in the 2nd experimental group it was 76.56 kg, which was by 6.96 kg more. The average daily live weight gain of animals in the 1st and 2nd experimental groups was higher than in the control by 6.55 and 10.00 %, respectively. The use of a biologically active additive in addition to the main diet had a positive eff ect on the formation of meat productivity of fattened young pigs in the experimental groups. The pigs of the 1st and 2nd experimental groups exceeded the control group in slaughter weight by 5.35 and 7.81 %, respectively, in hot carcass weight by 5.13 and 7.39 %, in slaughter yield by 0.5 and 0.7 abs.%. Economic effi ciency in monetary terms was higher in the experimental groups. The use of Bifidumbacterin in feeding of young pigs made it possible to reduce the prime-cost of 1 centner of live weight gain by 294.14–423.17 rubles and increase the level of profitability of pork production by 7.26–10.74 abs.%.

Morphometric evaluation of guinea pigs (Cavia Porcellus) in Southern Peru

The aim of this study was the morphometric evaluation of guinea pigs in southern Peru. The study was carried out at the Agrarian Experimental Station Illpa (AESI) of the National Institute of Agrarian Innovation (NIAI) in Puno at 3824 meters above sea level. 120 guinea pigs were used (females n = 60 and males n = 60) with an average age of 22 days. The morphometric characteristics evaluated were: body weight (BW), chest circumference (CC), abdominal perimeter (AP), neck perimeter (NP), head length (HL) and head width (HW). To evaluate the effect of sex on morphometric characteristics, a completely randomized design was used. To determine the equation that best predicts body weight, stepwise regression was used, and correlations between morphometric characteristics were obtained using Pearson's correlation. The results show that the sex factor does not significantly influence BW, CC, AP, NP, HL, and HW (p≥0.05); likewise, the equation that best predicts the body weight of the guinea pigs was: BW = -530.50 + 21.98(CC) + 12.72(AP) + 10.16(NP) + 57.23(HW), with R2 = 84%. Pearson correlations between morphometric characteristics were of high magnitude, positive, and statistically significant (p&lt;0.001). It is concluded that in conditions of the Peruvian highlands, the sex factor does not influence the morphometric characteristics. It is also possible to predict body weight from CC, AP, NP, and HW, and the correlations were high and positive.

Comprehensive Analysis of Placental DNA Methylation Changes and Fetal Birth Weight in Pigs.

Birth weight is a complex multifactorial trait relevant to health states and disease risks in later life. The placenta is essential for proper fetal growth and facilitates gas, nutrient, and waste exchange between the mother and developing fetus. How changes in placental DNA methylation affect fetal birth weight remains to be fully elucidated. In this study, we used whole-genome bisulfite sequencing and RNA sequencing to reveal a global map of DNA methylation and gene expression changes between the placentas of highest birth weight and lowest birth weight piglets in the same litters. The transcriptome analysis identified 1682 differential expressed genes and revealed key transcriptional properties in distinct placentas. We also identified key transcription factors that may drive the differences in DNA methylome patterns between placentas. The decrease in DNA methylation level in the promoter was associated with the transcriptional activation of genes associated with angiogenesis, extracellular matrix remodeling, and transmembrane transport. Our results revealed the regulatory role of DNA methylation in gene transcription activity leading to the differences in placental morphological structures and birth weights of piglets. These results could provide novel clues to clarify the underlying regulatory mechanisms of placental development and fetal growth.

Reference Intervals of Mass Coefficients and Absolute Weights of Mini Pigs’ Organs

Introduction. Measurement of weights and calculation of mass coefficients of the laboratory animals’ internal organs are the integral stages of toxicological research. However, the absence of the correct intra-laboratory reference intervals corresponding to the normal values established for the animal population of a research laboratory could hinder the analysis of the mass coefficient changes in the experiment. For example, the data on weights and mass coefficients of mini pigs’ organs is being an issue due to its insufficient availability in the open sources. At the same time, in the literature there is a lot of such kind of data referring to the industrial pig breeds. Due to the wide use of the mini pigs in the pre-clinical research and because in the pig species taxonomy they are considered to be a weight category representing the pigs with reduced mass of the body with similar morphology of the organs and body systems, we have set an objective to determine and calculate the reference intervals of mass coefficients of internal organs relative to the mass of the body and brain, as well as the absolute weights of mini pigs’ internal organs and compare the results with the data on mini and industrial pig breeds in the literature sources.Materials and Methods. The data on 29 males and 29 females of the Vietnamese lop-bellied mini pig breed aged 6 months and older, who used to be in control groups of the various experiments held at JSC “SPA “House of Pharmacy” (Leningrad region) in the period from January 2018 to March 2024, was used to calculate the reference intervals. The statistical analysis was peRussian Federationormed using Microsoft Excel and Reference Value Advisor v2.1 software in compliance with the CLSI guidelines. Calculation of the reference intervals for all parameters was carried out by a robust method, the compliance with the normal distribution law was determined by Anderson–Darling test, in case of abnormal distribution of data, calculation of the reference interval was carried out with the Box–Cox transformation.Results. The data on the absolute weights of organs and their coefficients relative to the body and brain masses were presented in the form of the lower and upper reference limits and confidence intervals for each of the limit. The reference intervals of masses of organs across all parameters in males and females had similar limits, the most comparable values were found for the heart and brain parameters. The calculated interval of the heart absolute weight in males was 28.3–253 g, that of the brain was 46.5–93.7 g; in females these intervals were 42.9–279 g and 55.5–81.8 g respectively. Upon comparing the obtained data with the literature sources, it was found that the majority of the absolute weights of all measured mini pigs’ organs had fitted in the limits of the reference values, whereas the masses of the lungs and liver were at the lower limit or below the calculated intervals. The values of the absolute weights of most of the organs of the industrial pig breeds were higher than that of mini pigs, which was due to the difference in the body size and mass of the studied animal breeds. When comparing the mass coefficients of organs in relation to the body mass, it was found that the coefficients of most organs of the industrial breeds and mini pigs, on the contrary, were within the calculated reference intervals or slightly exceeded them.Discussion and conclusion. The calculated reference intervals of the mass coefficients of some organs in relation to the body mass, as well as the absolute weights of the spleen in mini pigs are comparable with the data available in literature for the industrial meat pig breeds. At the same time, the data available in the literature sources on the absolute weights of organs and their mass coefficients relative to the body mass of mini pigs, in most cases, have fitted into the calculated intervals. To increase the prognostic value of the obtained reference intervals, the analysis of a larger size sample is necessary.

Estimation of Energy Balance throughout the Growing–Finishing Stage of Pigs in an Experimental Pig Barn

Monitoring the energy inputs and outputs in pig production systems is crucial for identifying potential imbalances and promoting energy efficiency. Therefore, the objective of this study was to measure the energy input, output, and losses during the growing–finishing phase of pigs from 1 September to 1 December 2023. A Livestock Environment Management System (LEMS) was used to measure the temperature, humidity, airflow, and water consumption levels inside the barn, and a load cell was used to measure the body weight of pigs. Furthermore, a bomb calorimetric test was conducted to measure the energy content of pigs’ manure. While calculating energy balance in the experimental barn, it was found that energy from feed and water contributed approximately 81% of the total input energy, while the remaining 19% of energy came from electrical energy. Regarding output energy, manure, and body weight accounted for about 69%, while around 31% was lost due to pig activities, maintaining barn temperature and airflow, and illuminating the barn. In conclusion, this study suggested methods to calculate energy balance in pig barns, offering valuable insights for pig farmers to enhance their understanding of input and output energy in pig production.

#598 Successful application of allo-hemodialysis in a porcine model of embolization-induced acute kidney injury

Abstract Background and Aims Annually, millions of kidney patients, primarily in low- and low-middle income nations, die prematurely due to the lack of affordable kidney replacement therapy. We propose a novel, low-cost alternative dialysis modality called allo-hemodialysis (alloHD), where blood of a patient with kidney failure flows counter-current to the blood of a healthy subject (“buddy”) through the dialyzer [1]. Uremic solutes and excess fluid are then excreted by the buddy's healthy kidneys. We have already demonstrated the technical feasibility of alloHD in pigs with acute kidney injury (AKI) induced by renal artery ligation [2]. In this study, we explored alloHD in a less invasive porcine model of AKI induced by renal artery embolization. Method The protocol was approved by the Committee for the Purpose of Control and Supervision of Experiments on Animals (CPCSEA), New Delhi, India. We studied two female Yorkshire pigs (weight 80-90 kg) with central venous catheter as vascular access. AKI was induced by embolization of both kidneys by transcatheter deployment of Contour™ Poly Vinyl Alcohol particles (Boston Scientific, Marlborough, MA, USA). The AKI pig and the buddy pig were connected to the dialysate and blood compartments, respectively, of a Nipro Cellentia 17H dialyzer. The AKI pig was then dialyzed for 4 hours against the healthy buddy pig. During alloHD, both pigs were anticoagulated with heparin (5,000 IU/h) and the buddy pig was sedated with 1-2% isoflurane gas. Blood samples were collected before, during, and after alloHD for measurements of blood urea nitrogen (BUN) and creatinine. Results We performed nine alternate day alloHD sessions with the same pair of pigs. During alloHD, BUN and Creatinine levels declined in the AKI pig (Fig. 1) and increased—as expected—transiently above baseline in the buddy pig and then trended towards baseline post-dialysis (Fig. 1). We found no indication of hemolysis or coagulation of the extracorporeal circuit in any of the nine alloHD sessions. The animals were sacrificed after the 9th session. Conclusion We demonstrated the feasibility of alloHD in a porcine embolization AKI model. This study corroborates and complements our previous experience with alloHD in a porcine model of AKI induced by renal artery ligation. Given these promising results, we are investigating the potential for advancing to a clinical trial.

Exogenous xylanase increases total tract digestibility of energy and fiber in diets for gestating and lactating sows, but does not influence reproductive performance of sows

The hypothesis that exogenous xylanase added to diets for gestating and lactating sows will increase the apparent total tract digestibility (ATTD) of gross energy (GE) and total dietary fiber (TDF), increase digestible energy (DE) and metabolizable energy, and improve the reproductive performance of sows was tested. Two diets for gestating sows and two diets for lactating sows were formulated without or with 100 g per ton of an exogenous xylanase (16,000 units/kg). Diets were fed in two consecutive reproductive cycles. From 106 animals, 48 pregnant sows, organized in 4 blocks of 12 sows (6 sows per treatment in each block), were placed for 10 days in metabolism crates starting on day 35 (mid-gestation) and again on day 95 (late-gestation) with feces and urine being collected for 4 days. Sows were moved to the lactation unit on day 106 of gestation and feeding of lactation diets was initiated. Fecal samples were collected (grab-sampling) from days 10–14 post-farrowing. The number and weight of pigs born, mummified, stillborn, and weaned per sow were recorded, and survival rate and litter average daily gain were calculated. Litters were weaned on day 20 ± 1. All animals were rebred and 46 sows were placed in metabolism crates in mid and late-gestation as in the first cycle, and treatments in the farrowing unit during the second cycle were also as in the first cycle; however, colostrum and milk samples were collected from sows in the second cycle. Results indicated that reproductive performance was not different between sows fed control diets and sows fed diets with xylanase during the two reproductive cycles. In the first gestation period, the ATTD of TDF in late-gestation was greater (P < 0.05) in sows fed the diet with xylanase than in sows fed the control diet. During the first lactation, sows fed the diet with xylanase had greater (P < 0.05) ATTD of GE and TDF, and greater (P < 0.05) DE than sows fed the control diet. During the second gestation, sows fed the diet with xylanase had greater (P < 0.05) DE in mid-gestation. During the second lactation, sows fed the diet with xylanase had greater (P < 0.05) ATTD of GE and TDF, and greater (P < 0.05) DE than sows fed the control diet. In conclusion, DE was greater in diets with xylanase than in control diets during the two reproductive cycles, and sows fed the lactation diet with xylanase had greater digestibility of fiber than sows fed the control diet.