Litter Size In Sows Research Articles

The genetic polymorphism ESR1_intron 3 (PvuII) and its relationship with litter size in sows: a meta-analysis

The genetic polymorphism ESR1_intron 3 (PvuII) and its relationship with litter size in sows: a meta-analysis

Analysis of the reproduction components trait litter size in sows and interaction with boar libido in indigenous pigs

Analysis of the reproduction components trait litter size in sows and interaction with boar libido in indigenous pigs

Development of a biomolecular approach to identify sperm functions and fertility using sperm RNAs.

Infertility affects a significant percentage of couples worldwide, and male factors contribute significantly to this problem. Traditional assessments of male fertility rely primarily on parameters such as sperm motility, morphology, viability, and concentration. However, these metrics often do not provide a comprehensive understanding of sperm function, which is critical not only for fertilization but also for successful embryo development. Herein, we used porcine spermatozoa as a model to investigate the potential of sperm RNA markers in assessing various aspects of sperm function from motility to fertility. Using artificial insemination, we evaluated male fertility based on the litter size of sows inseminated with sperm from 20 boars. In addition, we measured parameters such as weaning rate, death births, live births, and mummy births. Sperm functional parameters, including motility and kinematics, were assessed before and after in vitro capacitation. Finally, correlations between various sperm functional parameters and sperm RNA markers were explored. Our results revealed interesting relationships between sperm functional parameters. While motility and kinematics were correlated, they were not correlated with sperm capacitation status. Surprisingly, no significant correlations were found between these parameters and male fertility. However, specific parameters of sperm capacitation status after in vitro capacitation were correlated with weaning rate and live births, highlighting their importance in predicting successful fertilization. Further analysis of sperm RNA markers identified genes related to male fertility, including IZUMO1, known for its role in sperm-egg fusion. These genes showed correlations with motility, capacitation, and fertilization parameters, shedding light on their potential roles in sperm function. In conclusion, our study demonstrates that sperm RNA markers hold promise for the diagnosis and prognosis of various aspects of sperm function, providing valuable insights into male infertility. These markers may serve as diagnostic tools to improve our understanding of male fertility problems, ultimately benefiting couples struggling with infertility.

A meta-analysis: Effect of androgens on reproduction in sows.

The mechanisms by which male hormones affect the development of ovaries and follicles has been studied by injecting exogenous androgens into sows. This may provide a reference for human polycystic ovary syndrome (PCOS), and can also provide guidance for improving the litter size of sows. We present a meta-analysis of studies published in the past 30 years on the effect of androgens on the ovulation rate of sows. A total of 517 papers were analyzed. The results showed that both testosterone (T) and dihydrotestosterone (DHT) injected into sows were positively related to the ovulation rate. T did not have a relevant effect on swine in vivo blastocyst survival rate. DHT had a negative phase with respect to blastocyst survival rate. Pig T-androgen receiver affinity was higher than the analogous affinity for DHT; this is different in humans. This suggests that sows are not suitable as human PCOS experimental animal models. To improve the litter size of sows, future research should focus on the mixed use of T and DHT, and the timing of use should be consistent with the periodic changes in androgen levels in sows. In addition, the welfare of experimental sows should be considered with reference to the clinical symptoms of PCOS.

Effects of dietary valine-to-lysine ratio on placenta growth, the placental nutrient transporters, and reproductive performance in sows

Context Valine-to-lysine ratio (V:L) in the diet has been found to affect the placental development of sows, and thus the production performance, but the mechanism is still unclear. Aim To investigate the effects of the V:L on placental growth and reproductive performance of sow. Methods Twenty-seven sows (average parities = 5) from 85 days of gestation were randomly assigned into five experimental groups with five ratios of total V:L of 0.75:1, 0.87:1, 0.99:1, 1.11:1, 1.23:1. Litter size was recorded. The placenta and colostrum were collected immediately after farrowing for mRNA analysis. Key results The results showed that dietary valine increased the sows’ placental area and the fetal-to-placental weight ratio (P < 0.05). Dietary valine does not affect the litter size of sows, but significantly reduces the delivery time and accelerates the delivery process. Dietary valine improved the average daily feed intake of the sows in the lactation (P < 0.05) and decreased the number of stillborns (P < 0.05). Additionally, the placental gene expression of LAT1, 4F2hc, LAT2, LAT3, SNAT1, SNAT2, and SNAT4 increased in the groups whose diet contained higher V:L ratios (P < 0.01). The increase in the ratio of dietary V:L increased the expression of GLUT1, GLUT3 and GLUT4 genes in the placenta tissue (P < 0.01). Conclusions The results suggested that suitable V:L positively affects pregnant and lactating sow’s performance. Implications Therefore, V:L can be adjusted to promote sow reproductive performance and increase production efficiency.

Differential MicroRNA Expression in Porcine Endometrium Related to Spontaneous Embryo Loss during Early Pregnancy.

Litter size is an important indicator to measure the production capacity of commercial pigs. Spontaneous embryo loss is an essential factor in determining sow litter size. In early pregnancy, spontaneous embryo loss in porcine is as high as 20–30% during embryo implantation. However, the specific molecular mechanism underlying spontaneous embryo loss at the end of embryo implantation remains unknown. Therefore, we comprehensively used small RNA sequencing technology, bioinformatics analysis, and molecular experiments to determine the microRNA (miRNA) expression profile in the healthy and arresting embryo implantation site of porcine endometrium on day of gestation (DG) 28. A total of 464 miRNAs were identified in arresting endometrium (AE) and healthy endometrium (HE), and 139 differentially expressed miRNAs (DEMs) were screened. We combined the mRNA sequencing dataset from the SRA database to predict the target genes of these miRNAs. A quantitative real-time PCR assay identified the expression levels of miRNAs and mRNAs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed on differentially expressed target genes of DEMs, mainly enriched in epithelial development and amino acids metabolism-related pathways. We performed fluorescence in situ hybridization (FISH) and the dual-luciferase report gene assay to confirm miRNA and predicted target gene binding. miR-205 may inhibit its expression by combining 3′-untranslated regions (3′ UTR) of tubulointerstitial nephritis antigen-like 1 (TINAGL1). The resulting inhibition of angiogenesis in the maternal endometrium ultimately leads to the formation of arresting embryos during the implantation period. This study provides a reference for the effect of miRNA on the successful implantation of pig embryos in early gestation.

Discovery of Differentially Expressed MicroRNAs in Porcine Ovaries With Smaller and Larger Litter Size.

The number of live births in a litter is an important reproductive trait, and is one of the main indicators which reflect the production level and economic benefit of a pig farm. The ovary is an important reproductive organ of the sow, and it undergoes a series of biological processes during each estrous cycle. A complex transcriptional network containing coding and non-coding RNAs in the ovary closely regulates the reproductive capability of sows. However, the molecular regulation mechanisms affecting sow litter size are still unclear. We investigated the expression profiles of microRNAs (miRNAs) in porcine ovaries from sows with smaller than average litter sizes (SLS) and those with larger litter sizes (LLS). In total, 411 miRNAs were identified, and of these 17 were significantly down-regulated and 16 miRNAs were up-regulated when comparing sows with LLS and SLS, respectively. We further characterized the role of miR-183 which was one of the most up-regulated miRNAs. CCK-8, EdU incorporation and western blotting assays demonstrated that miR-183 promoted the proliferation of granulosa cells (GCs) in pig ovaries. Moreover, miR-183 inhibited the synthesis of estradiol in GCs and promoted the synthesis of progesterone. These results will help in gaining understanding of the role of miRNAs in regulating porcine litter size.

Transcriptome analysis reveals that long noncoding RNAs contribute to developmental differences between medium-sized ovarian follicles of Meishan and Duroc sows

Ovulation rate is an extremely important factor affecting litter size in sows. It differs greatly among pig breeds with different genetic backgrounds. Long non-coding RNAs (lncRNAs) can regulate follicle development, granulosa cell growth, and hormone secretion, which in turn can affect sow litter size. In this study, we identified 3554 lncRNAs and 25,491 mRNAs in M2 follicles of Meishan and Duroc sows. The lncRNA sequence and open reading frame lengths were shorter than mRNAs, and lncRNAs had fewer exons, were less abundant, and more conserved than protein-coding RNAs. Furthermore, 201 lncRNAs were differentially expressed (DE) between breeds, and quantitative trait loci analysis of DE lncRNAs were performed. A total of 127 DE lncRNAs were identified in 119 reproduction trait-related loci. In addition, the potential target genes of lncRNAs in cis or trans configurations were predicted. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that some potential target genes were involved in follicular development and hormone secretion-related biological processes or pathways, such as progesterone biosynthetic process, estrogen metabolic process, ovarian steroidogenesis, and PI3K-Akt signaling pathway. Furthermore, we also screened 19 differentially expressed lncRNAs in the PI3K-Akt signaling pathway as candidates. This study provides new insights into the roles of lncRNAs in follicular growth and development in pigs.

Polymorphism of OPN and AREG Genes in Relation to Transcript Expression of a Panel of 12 Genes Controlling Reproduction Processes and Litter Size in Pigs

Abstract The aim of this study was to define the transcript expression of 12 genes, identify new polymorphisms in selected 2 genes and to estimate the association between the level of expression, gene polymorphism and litter size in sows. Two groups of sows were selected: 71 crossbred sows and 328 purebred sows. For transcript analysis endometrial tissue samples were collected, while blood was sampled for the purpose of DNA polymorphism analysis. For all animals data on litter size and weaned piglets were obtained. Transcript analysis of 12 genes was performed in the uterine endometrium of sows in the luteal and follicular phases. Eight out of 12 genes showed higher mRNA expression levels during the luteal phase (AREG, FABP3, IL1A, ITGAV, ITGB3, NMB, OPN, RBP4). In turn, higher expression levels in the follicular phase were observed for 4 genes (IL1B, PPARG, S100A8, SELL). Analysis of six new polymorphic sites within the OPN and AREG genes revealed the highest heterozygosity for OPNe6_Knoll, OPNp3_617 and AREGe2_317 polymorphisms and the lowest heterozygosity in the AREGe3_561 locus. Association analyses concerning transcript expression levels of the 12 genes and the OPN and AREG genotypes in the two groups of sows showed a significant relationship between the IL1A, ITGB3 transcript expression and the OPNe7_603 genotype also between OPNp3_617 genotype and ITGB3 transcript expression. With regard to the litter size and the number of weaned piglets a significant relation with the OPNp3_617, OPNe6_462 and AREGe2_317 genotypes was observed only in the purebred sows. Transcript expression of the genes encoding osteopontin and amphiregulin in the uterus of the sows affect reproductive traits by preparing the uterus for embryo reception.

Genome-wide association studies reveals polygenic genetic architecture of litter traits in Duroc pigs

With continuous improvement of sow litter size, breeders are gradually paying more attention to the quality of litter traits that directly impact the production efficiency of pig companies, such as the rate of piglets born alive (RBA) and the rate of healthy births (RHB). The objectives of this study are to dissect the genetic basis of litter traits in pig and to identify valuable genes and genetic markers, especially pleiotropic, for pig breeding. Herein, 1140 Duroc pigs and 2046 reproduction records, 5 litter traits, including the number of healthy births (NHB), number of deformed fetuses (NDF), number of stillborn (NSB), RBA, and RHB, were used in this study. Subsequently, a genome-wide association study (GWAS) was performed for the five litter traits in the first two parities from two Duroc populations. A total of 76 significantly related SNPs and 10 potential candidate genes (CAV1, DAB2, FGF12, FHOD3, DYNC2H1, GRHL1, TCTN3, PYROXD2, MMP8, MMP13, and PGR) were detected, including 13 pleiotropic SNPs that affected more than one litter trait. Finally, the functional enrichment analysis of functional genes that were closest to these significant SNPs indicated that most of the significant pathways were associated with hormone secretion and embryo and organ development. This study advances our understanding of the genetic mechanisms of litter traits, especially the survival rate of piglets born, and provides an opportunity to increase the quality of litter using marker-assisted selection or genomic selection in pigs.

Integrated Insight into the Molecular Mechanisms of Spontaneous Abortion during Early Pregnancy in Pigs.

Due to the high rate of spontaneous abortion (SAB) in porcine pregnancy, there is a major interest and concern on commercial pig farming worldwide. Whereas the perturbed immune response at the maternal–fetal interface is an important mechanism associated with the spontaneous embryo loss in the early stages of implantation in porcine, data on the specific regulatory mechanism of the SAB at the end stage of the implantation remains scant. Therefore, we used high-throughput sequencing and bioinformatics tools to analyze the healthy and arresting endometrium on day 28 of pregnancy. We identified 639 differentially expressed lncRNAs (DELs) and 2357 differentially expressed genes (DEGs) at the end stage of implantation, and qRT-PCR was used to verify the sequencing data. Gene set variation analysis (GSVA), gene set enrichment analysis (GSEA), and immunohistochemistry analysis demonstrated weaker immune response activities in the arresting endometrium compared to the healthy one. Using the lasso regression analysis, we screened the DELs and constructed an immunological competitive endogenous RNA (ceRNA) network related to SAB, including 4 lncRNAs, 11 miRNAs, and 13 genes. In addition, Blast analysis showed the applicability of the constructed ceRNA network in different species, and subsequently determined HOXA-AS2 in pigs. Our study, for the first time, demonstrated that the SAB events at the end stages of implantation is associated with the regulation of immunobiological processes, and a specific molecular regulatory network was obtained. These novel findings may provide new insight into the possibility of increasing the litter size of sows, making pig breeding better and thus improving the efficiency of animal husbandry production.

Predictive Capacity of Boar Sperm Morphometry and Morphometric Sub-Populations on Reproductive Success after Artificial Insemination.

Simple SummaryThe efficiency of swine production measured as litter size influences the profitability of the pig industry. Furthermore, sow fertility potential depends in part on the boar semen quality and reproductive efficiency. The objective of this study is to compare boar sperm head size and morphometric features of shape to evaluate their relationships with reproductive success after artificial insemination (AI). A morphometric analysis of boar ejaculate reveals morphometrically separate sub-populations. The differences between sub-populations are displayed for sperm head size. In addition, sperm clustering into sub-populations did not have a predictive capacity on litter size variables. Nevertheless, the morphometric variables of the sperm may have a predictive, albeit reduced, capacity regarding litter size variables. The results of this study therefore open up possibilities for future assessments of fertility. The aim of the study was to compare the morphometric features of sperm head size and shape from the Pietrain line and the Duroc × Pietrain boar crossbred terminal lines, and to evaluate their relationship with reproductive success after artificial insemination of sows produced from crossbreeding the York, Landrace and Pietrain breeds. Semen samples were collected from 11 sexually mature boars. Only ejaculates with greater than 70% motility rate and <15% of abnormal sperm were used for artificial inseminations (AI) and included in the study. Samples were analyzed using an ISAS®v1 computer-assisted sperm analysis system for eight morphometric parameters of head shape and size (CASA-Morph). Sub-populations of morphometric ejaculates were characterized using multivariate procedures, such as principal component (PC) analysis and clustering methods (k-means model). Four different ejaculate sub-populations were identified from two PCs that involved the head shape and size of the spermatozoa. The discriminant ability of the different morphometric sperm variables to predict sow litter size was analyzed using a receiver operating characteristics (ROC) curve analysis. Sperm head length, ellipticity, elongation, and regularity showed significant predictive capacity on litter size (0.59, 0.59, 0.60, and 0.56 area under curve (AUC), respectively). The morphometric sperm sub-populations were not related to sow litter size.

Swine Ultrasonography Numerical Modeling for Pregnancy Diagnosis and Prediction of Litter Size

Early and reliable diagnosis of pregnancy in sows is considered one of the most crucial parameters for the proper management in pig farming. Reproductive activity of the sows is directly correlated with the overall productivity of the enterprise. The best and most precise methodology to diagnose pregnancy in farm animals, including pigs, is ultrasonography. For getting optimal outputs of real-time ultrasonography application in pigs, both gestation status and litter size of sows is of high importance. Hence, a detailed evaluation and careful reading of the retrieved ultrasonic image could serve to the prediction of the sow’s litter size, providing valuable information to the producer. In the present article we studied the ultrasonic typification of sows in an effort to develop a methodology for the precise pregnancy diagnosis and the prediction of the litter size. To achieve this goal, 1214 matings and 1010 pregnancies were recorded and evaluated over a period of 20 months, in a pig unit in Northern Greece. Two thorough scans were performed on each sow, classifying the ultrasonic image in a scale of 0 to 10, 0 being ‘non pregnant’ and 10 given to the most reassuring image of pregnancy. Evaluations took place in a wide range of time since mating, hence between days 16 (the earliest first scan) and 68 (the latest that a second scan was performed) and the mean values obtained were 8,36 and 8,83 for the first and second scan respectively. Furthermore, the litter size of each subsequent parturition was recorded (mean: 12.22) and correlated to the score of each of the two scans performed during pregnancy. The results showed that more reassuring images and higher scores for both examinations of pregnancy were achieved with increasing time interval from mating (P&lt;0.05). It is therefore suggested that a detailed real-time ultrasonic scanning, can provide a very useful tool, not only for pregnancy diagnosis, but also for the prediction of litter size and eventually the precise management of pregnant sows.

SMARCA2 is regulated by NORFA-miR-29c, a novel pathway that controls granulosa cell apoptosis and is related to female fertility.

SMARCA2, an evolutionarily conserved catalytic ATPase subunit of SWI/SNF complexes, has been implicated in development and diseases; however, its role in mammalian ovarian function and female fertility is unknown. Here, we identified and characterized the 3'-UTR of the porcine SMARCA2 gene and identified a novel adenylate number variation. Notably, this mutation was significantly associated with sow litter size traits and SMARCA2 levels, due to its influence on the stability of SMARCA2 mRNA in ovarian granulosa cells (GCs). Immunohistochemistry and functional analysis showed that SMARCA2 is involved in the regulation of follicular atresia by inhibiting GC apoptosis. In addition, miR-29c, a pro-apoptotic factor, was identified as a functional miRNA that targets SMARCA2 in GCs and mediates regulation of SMARCA2 expression via the NORFA-SMAD4 axis. Although a potential miR-29c-responsive element was identified within NORFA, negative regulation of miR-29c expression by NORFA was not due to activity as a competing endogenous RNA. In conclusion, our findings demonstrate that SMARCA2 is a candidate gene for sow litter size traits, because it regulates follicular atresia and GC apoptosis. Additionally, we have defined a novel candidate pathway for sow fertility, the NORFA-TGFBR2-SMAD4-miR-29c-SMARCA2 pathway.This article has an associated First Person interview with the first author of the paper.

88 Benefits of increasing amino acid intake in late gestation in prolific sows

Abstract Most sows are fed a constant energy and amino acid supply throughout gestation, in line with the recommendations of most authorities and swine genetic companies. These recommendations for sow feeding have seen little change in decades, despite the many ways that sows have changed dramatically in reproductive performance. Beginning in about the year 2000, sow litter size has steadily increased as a result of genetic selection. With this increase in litter number has been a steady decline in birth weight, and the resulting negative effects of lower birthweight on subsequent piglet performance. Many experiments using so-called ‘bump’ feeding, or increased energy intake in late gestation, have been conducted in attempts to arrest this decline in birthweight and piglet performance. Generally, these experiments have shown little to no improvement in birthweight and often have negative effects on sow feed intake during gestation. These experiments have ignored the fact that the energy:amino acid ratios (lysine, threonine, isoleucine, tryptophan) in late gestation are different than during early and mid-gestation. In recent research in Australia we hypothesised that rapidly increasing essential amino acid levels in late gestation would increase birth weight and potentially improve subsequent reproductive performance. Three hundred and thirty-four multiparous PIC sows (average parity 3.6, average LW 261 kg) were housed in a dynamic gestation pen after mating and randomly assigned to one of two diet regimes. Two 13.5 MJ/kg DE gestation diets were formulated and created by blending in an ESF. The Control diet contained 0.48 g SID lysine per MJ DE and SID threonine, methionine+ cysteine, isoleucine and tryptophan at 68%, 65%, 58% and18% of SID lysine and offered at 2.2kg/day from d 28 to d 110. Sow were then moved to the farrowing house and placed on a lactation diet at 3.5kg/d. The Treatment diet contained 0.55 g SID lysine/MJ DE and SID threonine, methionine+cysteine, isoleucine and tryptophan at 78%, 65%, 60% and 20% of SID lysine and offered at 2.1kg/d from d 28 to d 85 and then increased to 2.4 kg/d to d 110 d. Increasing essential amino acid levels in late gestation increased gestational weight gain (5.6 kg, P=0.004), increased total litter birth weight (1.25 kg, P=0.003), and increased the birthweight of liveborn pigs from 1.286 to 1.329 kg, (P=0.04). There was no significant effect on the total number born or born alive. Piglet performance is not available because this commercial farm practices cross-fostering. Effects of continuation of this feeding regime in the same sows during subsequent parities is currently being evaluated.

DMEM and FBS as thawing solutions for frozen semen of pigs can improve sperm motility and sow reproductive performance

The purpose of this experiment was to investigate the effects of Beltsville thawing solution BTS , Androhep, and Dulbecco?s modified Eagle medium + Fatal bovine serum D-F as diluents of frozen semen on sperm motility and sow reproductive performance. In experiment 1, boar semen was collected and diluted to 2.0 × 109/60 mL, 1.5 × 109/60 mL, and 1.5 × 109/40 mL with Androhep. The appropriate semen dose was determined by postcervical insemination. In experiment 2, boar semen was fumigated with liquid nitrogen and thawed semen was diluted to 1.5 × 109/40 mL with D-F, Androhep, and BTS, respectively. The effects of above diluents on sperm motility and sow reproductive performance were studied by postcervical insemination. The appropriate semen dose for postcervical insemination was 1.5 × 109/40 mL. After thawing of frozen semen, sperm motility of semen diluted with D-F was significantly higher than that of semen diluted with Androhep and BTS. There was no significant difference in pregnancy rates among sows via artificial insemination. The litter size of sows using D-F diluted semen was significantly higher than that of sows using Androhep and BTS diluted semen. In conclusion, D-F freezing diluent can improve sperm motility of frozen boar semen after thawing, prolong sperm survival time, and increase sow reproductive performance.

Effect of dietary L-carnitine supplementation to sows during gestation and/or lactation on sow productivity, muscle maturation and lifetime growth in progeny from large litters.

Genetic selection for increased sow prolificacy has resulted in decreased mean piglet birth-weight. This study aimed to investigate the effect of L-carnitine (CAR) supplementation to sows during gestation and/or lactation on sow productivity, semitendinosus muscle (STM) maturity, and lifetime growth in progeny. Sixty-four sows were randomly assigned to one of four dietary treatments at breeding until weaning; CONTROL (0mg CAR/d), GEST (125mg CAR/d during gestation), LACT (250mg CAR/d during lactation), and BOTH (125mg CAR/d during gestation & 250mg CAR/d during lactation). The total number of piglets born per litter was greater for sows supplemented with CAR during gestation (17.3 v 15.8 ± 0.52; P<0.05). Piglet birth-weight (total and live) was unaffected by sow treatment (P>0.05). Total myofibre number (P=0.08) and the expression level of selected myosin heavy chain genes in the STM (P<0.05) was greater in piglets of sows supplemented with CAR during gestation. Pigs from sows supplemented with CAR during gestation had lighter carcasses at slaughter than pigs from non-supplemented sows during gestation (83.8 v 86.7 ± 0.86kg; P<0.05). In conclusion, CAR supplementation during gestation increased litter size at birth without compromising piglet birth-weight. Results also showed that the STM of piglets born to sows supplemented with CAR during gestation was more developed at birth. However, carcass weight at slaughter was reduced in progeny of sows supplemented with CAR during gestation. The CAR supplementation strategy applied during gestation in this study could be utilized by commercial pork producers to increase sow litter size and improve offspring muscle development.

Method of individual forecasting of sow reproductive performance on the basis of a non-linear canonical model of a random sequence

Improvement of sow reproductive performance is a key factor determining the efficiency of the pig production cycle and profitability of pork production. This article presents the solution of an important scientific and practical problem of individual forecasting of sow reproduction . The population used for the present study is from a pig farm managed by the Limited Liability Company (LLC) ‘Tavriys’kisvyni’ located in Skadovsky district (Kherson region, Ukraine). The experimental materials used for this study consisted of 100 inds. of productive parent sows of the Large White breed.The litter size traits – the total number of piglets born (TNB), number of piglets born alive (NBA) and number of weaned piglets (NW) – were monitored in the first eight parities over an eleven year period (2007–2017). The method of the forecasting of sow litter size is developed based on the non-linear canonical model of the random sequence of a litter size change. The proposed method allows us to take maximum account of stochastic peculiarities of sow reproductive performance and does not impose any restrictions on the random sequence of a litter size change (linearity, stationarity, Markov property, monotony, etc.). The block diagram of the algorithm presented in this work reflects the peculiarities of calculation of the parameters of a predictive model. The expression for the calculation of an extrapolation error allows us to estimate the necessary volume of a priori and a posteriori information for achieving the required quality of solving the forecasting problem. The results of the numerical experiment confirmed the high accuracy of the proposed method of forecasting of sow reproduction. The method offered by us almost doubles the accuracy of forecasting of sow litter size compared to the use of the Wiener and Kalman methods. Thus, average forecast error decreases across the range of features TNB (1.71), NBA (1.68) and NW (1.25 piglets). Apparently, this may reflect a higher level of manifestation of the genetically determined level of individual sow fertility at the moment of piglet weaning. The higher adequacy of the developed mathematical model with regard to NW can be also due to the fact that the relations between sow litter size in different farrowings primarily have a non-linear character, which is taken into maximum account in our offered model. Given non-linearity, on the other hand, turns out to be a significant factor determining a lower estimation of the repeatability value for NW compared to the estimations for TNB and NBA. The use of the developed method will help to improve the efficiency of pig farming.

283 Ordered logistic regression analyze the effect of elements in serum and seminal plasma on abnormal sperm rate in boars

Abstract Poor sperm morphology decrease sow litter size and the economic profitability of breeding herds. Our previous results revealed elements in serum and seminal plasma, such as copper, iron, and lead affects abnormal sperm rate (ABR) in boars. In this study, sperm morphology and elements in serum and seminal plasma of 385 boars were analyzed using CASA and ICP-MS, respectively from June to August in 2016. Multivariate ordered logistic regression model, which includes variables of boar breed, age, serum and seminal plasma elements was used to identify the influence degree of elements on ABR. The degree of ABR was classified grade 0: &amp;lt; 10%, grade 1: 10–20%, and grade 2: &amp;gt; 20%. Results showed ABR was influenced by boar breed, serum Cu and Fe, and seminal Pb contents (P &amp;lt; 0.0001). Yorkshire boars (OR: 0.321; CI: 0.187 to 0.551) and Landrace boars (OR: 0.224; CI: 0.135 to 0.371) had lower ABR than Duroc boars. Boars with serum Cu ≤2.0 mg/L had lower ABR than those with serum Cu ≥2.5 mg/L (OR: 0.483; CI: 0.281 to 0.830). ABR of boars with serum Fe ≤ 1.0mg/L was greater than that of boars with serum Fe 1.5 mg/L (OR: 2.213; CI: 1.188 to 4.120). In addition, boars with seminal plasma Pb 0 μg/L had lower ABR than those with seminal Pb ≥ 10 μg/L (OR: 0.362; CI: 0.174 to 0.757). In conclusion, Duroc boars had more risk of ABR compared with Yorkshire and Landrace boars. The decrease of seminal plasma Pb and serum Cu, and increased of serum Fe content can decrease ABR in boars.

Antioxidant supplementation mitigates DNA damage in boar (Sus scrofa domesticus) spermatozoa induced by tropical summer.

Heat stress-induced sperm DNA damage has recently been demonstrated in boars during tropical summer; which could negatively impact early embryo survival and litter size in sows. Given the boar’s inefficient capacity to sweat, non-pendulous scrotum and low antioxidant activity in seminal plasma, elevated endogenous levels of antioxidants are needed to combat reactive oxygen species induced during periods of heat stress. This should prevent the build-up of pathological levels of DNA damage in boar spermatozoa. Our aim was to investigate whether a combined antioxidant supplement could mitigate sperm DNA damage in boars exposed to tropical summer conditions. Terminal deoxynucleotidyl transferase dUTP nick end labelling and flow cytometry of 20,000 spermatozoa/boar/treatment revealed that boar diets supplemented with 100 g/day custom-mixed antioxidant during peak wet summer effectively reduced sperm DNA damage by as much as 55% after 42 and 84 days treatment respectively (16.1 ± 4.9 peak wet control vs. 9.9 ± 4.5 42 day vs. 7.2 ± 1.6% 84 day treatments; P ≤ 0.05). Supplementation did not improve sperm concentration beyond control levels for either season (P > 0.05); nor alter total motility, progressive motility or several other motion parameters measured by computer assisted sperm analysis of 20 x 106 sperm/mL at 38°C (P > 0.05). Antioxidant supplementation during tropical summer appears to mitigate the negative impact of heat stress on DNA integrity but not concentration nor motility of boar spermatozoa; which may provide one solution to the problem of summer infertility in the pig.