Number Of Born Alive Research Articles

Traits Defining Sow Lifetime Maternal Performance.

Simple SummaryIn pig production, the ability of a sow to produce and rear a high number of viable piglets that meet weight targets for a desired age at slaughter is the ultimate goal. To achieve this, both management and breeding programs have to be tailored and continuously optimized. Reproductive characteristics, maternal attributes, and the ability to maintain body condition are highly variable, both within sows and amongst sows. For individual sows, maternal performance alters with age, and the environmental factors have a large impact on sow performance. This study demonstrated that the sow influences the number of high-quality slaughter pigs produced, which is not solely related to variation in litter size. Accounting for the sow’s influence on the number of tail-enders in breeding programs could assist with producing more high-quality slaughter pigs.Declining sow performance with increasing parity or an increase in the number of poor- quality pigs potentially impacts on farm productivity. This study investigated the phenotypic and genetic background of the sow’s influence on (i) the number of pigs not meeting the industry standards (tail-enders) and (ii) changes in performance with parity. Data were available for 3592 sows and their litters (13,976 litters) from a pig production system in NSW, Australia. The mean, standard deviation (SD), and slope for trait values over time were estimated for the sow characteristic traits: number of born-alive (NBA) and stillborn (SB) piglets and body condition of sow recorded with a caliper (CAL), along with maternal effects on piglet performance, represented by: average piglet birth weight (APBW), number of weaned piglets (WEAN), and tail-enders (TEND). Traits were analyzed in ASReml 4.2, by using an animal model. The number of tail-enders produced by a sow is a heritable trait, with a heritability estimate of 0.14 ± 0.04. Sow characteristics and maternal effects on piglet performance expressed by mean and slope had similar heritability estimates, ranging from 0.10 ± 0.03 to 0.38 ± 0.05, whereas estimates for SD traits were generally not different from zero. The latter suggests individual variability in sow characteristics or maternal performance between parities is largely not genetic in origin. This study demonstrated that more attention is required to identify contributions to the problem of tail-enders, and that slope traits could potentially be useful in the breeding program to maximize lifetime performance.

A genome-wide association study of important reproduction traits in large white pigs

Augmenting the reproductive efficiency of sows remains the predominant challenge in the swine industry. This work was aimed at scrutinizing vital genetic markers for reproductive traits in this animal. This entailed probing of the records of vital attributes of Large White pigs (n = 695) inclusive of the total number of born (TNB), number of born alive (NBA), number of weaned pigs (NWP), number of healthy births (NHS), total litter weight of piglets born alive (BALWT), weaning litter weight (WNWT), and corrected litter weight at 21 days (W21). A genome-wide association study (GWAS) for the four litter traits and three traits of litter weight in the Denmark Large White population then ensued. We discovered seven significantly related SNPs and eleven potential candidate genes (e.g., TUSC3, THRB for TNB; STT3B for NBA). The subsequent functional enrichment analysis of these genes showed that the significant gene were associated with steroid hormone receptor activity. Our findings indicated that the genes TUSC3, THRB and STT3B probably contribute to litter traits in this population. This work reveals genetic mechanisms of reproduction traits and also supports ensuing genetic improvement employing marker-assisted selection in Large White pigs.

Digestive efficiency traits in growing pigs are genetically correlated with sow litter traits in the Large White breed

Digestive efficiency traits are promising selection criteria to improve feed efficiency in pigs. However, the genetic relationships between digestive efficiency and sow reproductive traits are mostly unknown and need to be estimated. In this study, reproductive traits were available for 61 601 litters recorded on 21 719 Large White purebred sows. The traits were comprised of the number of born alive (NBA) and the number of weaned piglets (NWP), the number of stillbirths (NSB) and piglet mortality during suckling (PM). For a subset of 32518 litters, the mean (MBW) and CV of piglet birth weights (CVBW) were deduced from individual piglet weights as well as the proportion of piglets weighing less than 1 kg (PPL1K). Growth and feed efficiency traits were available for 4 643 Large White male pigs related to sows with reproductive performances. They comprised average daily gain (ADG), daily feed intake (DFI) and feed conversion ratio (FCR). A subset of 1 391 pigs had predictions for digestibility coefficients (DC) of energy, organic matter and nitrogen obtained by analysing faecal samples with near-infrared spectrometry. Estimated heritabilities were low for NBA, NSB, NWP and PM (0.08 ± 0.01 to 0.11 ± 0.01) and low to moderate for litter weight characteristics (0.14 ± 0.02 to 0.38 ± 0.01). Heritability estimates were moderate to high for ADG, DFI and FCR (0.37 ± 0.04 to 0.54 ± 0.05) and moderate for DC traits (0.26 ± 0.06 to 0.38 ± 0.07). Genetic correlations were low between ADG, or alternatively FCR, and reproductive traits. They were significantly different from zero with MBW (0.19 ± 0.06 with ADG and −0.15 ± 0.06 with FCR) and PPL1K (−0.19 ± 0.07 with ADG and 0.18 ± 0.07 with FCR). All genetic correlations between DFI and reproductive traits were low and not significantly different from zero. Genetic correlations between DC traits and NBA were significantly different from zero for DC of organic matter and energy (<−0.25 ± 0.11). DC traits were moderately correlated with MBW (>0.30 ± 0.11), CVBW (<−0.36 ± 0.11) and PPL1K (<−0.37 ± 0.11) at the genetic level. Genetic correlations between DC traits and PM were significantly negative and hence favourable (<−0.38 ± 0.12). Finally, genetic correlations between DC traits and NWP were close to zero. These results suggested that sows closely related to growing pigs with the best digestive efficiency would produce heavier and more homogeneous piglets, with slightly smaller litter sizes at birth but better survival. Hence, there is usable genetic variation in DC that could be exploited to define new selection strategies in maternal lines aiming at improving not only feed efficiency but also piglet survival.

Associations between animal and herd management factors, serological response to three respiratory pathogens and pluck lesions in finisher pigs on a farrow-to-finish farm

BackgroundSerological screening is a common method to monitor antibody response to pathogen exposure, but results could vary due to several factors. This study aimed to quantify animal and management related factors associated with variation in antibody levels in finisher pigs at slaughter, in an Irish farrow-to-finish farm endemically infected with Actinobacillus pleuropneumonia (App), Mycoplasma hyopneumoniae (Mhyo) and swine influenza virus (SIV). A second objective was to estimate differences in antibody levels in pigs presenting pluck lesions. This was an observational study whereby pigs were managed as per routine farm practice. Data on sow parity, number of born alive (NBA) pigs per litter, cross-fostering status, birth and weaning body weight were recorded from 1016 pigs born from one farrowing batch. At slaughter, blood samples were collected for serological analysis and pigs were inspected for presence of enzootic pneumonia (EP)-like lesions, pleurisy, pericarditis and heart condemnations. Pigs were retrospectively classified into three production flows, depending on time spent in each production stage: flow 1 (F1; pigs followed the normal production flow); flow 2 (F2; pigs which were delayed by 1 week from advancing forward); and flow 3 (F3; pigs delayed by > 1 week from advancing forward). A nested case-control design was applied by matching pigs from each flow by sow parity, birth weight and NBA.ResultsPigs born from primiparous sows had higher antibody levels for App than those born to parity ≥5 sows (P < 0.05) and there was no association between any of the pathogens investigated and other early life indicators (P > 0.05). Pigs in F1 had lower antibody levels for App but higher antibody levels for SIV than F2 and F3 pigs (P < 0.05). There was no association between pluck lesions and respiratory pathogens (P > 0.05), except for increased antibody levels for Mhyo when EP-like lesions were present (P = 0.006).ConclusionResults indicate that offspring from primiparous sows develop higher antibody levels for App IV toxin when exposed to this disease and that enforcement of a strict all-in/all-out production system would reduce on-farm disease circulation. A high percentage of pigs were affected with EP-like lesions which were associated with higher antibody levels for Mhyo.

Effects of follicle-stimulating hormone beta subunit and nuclear receptor coactivator 1 gene polymorphisms and expressions on pink-eyed white mink reproductive traits

The present study was designed to investigate comparative expressions of follicle-stimulating hormone beta subunit (FSHβ) and nuclear receptor coactivator 1 (NCOA1) genes by real-time polymerase chain reaction, using polymerase chain reaction single-strand conformation polymorphism methods to investigate the effects of gene polymorphisms on reproductive traits, including total number of kits born (TNB) and number of born alive (NBA) in pink-eyed white mink. Four single-nucleotide polymorphisms were identified in the FSHβ and NCOA1 genes. The g.1228G&gt;A polymorphism of FSHβ was associated with NBA and TNB (P &lt; 0.01). The g.151536T&gt;C polymorphism of NCOA1 was associated with NBA and TNB (P &lt; 0.01). The NCOA1 mRNA levels in hypothalamus, ovary, and uterus during the first half of gestation were higher than during the middle term and last half of gestation (P &lt; 0.01). The FSHβ mRNA levels in the hypothalamus and uterus were higher during the first half of gestation than during the middle term and last half of gestation (P &lt; 0.05). In conclusion, the g.1866T&gt;C polymorphism of FSHβ and the g.151536T&gt;C polymorphism of NCOA1 could be molecular markers for reproductive traits, and expressions of FSHβ and NCOA1 might be involved in the regulation of embryo attachment mechanisms in pink-eyed white mink breeding.

PRLR-AluI Gene Polymorphism And Litter Size Traits In Highly Prolific Line Of Topigs 20 Sows

Abstract The objective of the present study was to identify the Prolactin Receptor (PRLR) gene polymorphism related to litter size traits. The study included 101 Topigs 20 line of sows with 426 litters. The traits studied were: Total Number of Born (TNB), Number of Born Alive (NBA), Number of Still Born (NSB), and Number of MUMmified (NMUM) piglets. Polymorphism was identified with the polymerase chain reaction-restriction fragment length polymorphism method. Allelic and genotype frequencies and deviation from Hardy-Weinberg equilibrium were verified with the chi-square test. Analysis of litter size traits was performed using the General Linear Model, which included the potential environmental effects. Additive and dominant allele variances were observed by the regression procedure. In the studied population of sows, the frequency of heterozygotes (0.5149) for PRLR gene exceeded the total number of AA (0.0198) and BB (0.4653) homozygotes, which resulted in a high proportion of B allele (0.7228). The results for PRLR showed statistically significant (P&lt;0.05) differences in first parity sows between BB and AB genotypes for TNB and NBA. Significant differences (P&lt;0.05) were recorded in third parity sows between BB and AB genotypes for NBA, and in AA genotype versus AB and BB genotypes for NMUM. The fourth and subsequent parity sows of AA genotype had a significantly higher (P&lt;0.05) rate of NBA as compared with those of AB and BB genotypes. In all parities analysed, the difference between the BB and AB genotypes for NBA was statistically significant (P&lt;0.05). Interpretation of the results at the levels of phenotypes and either additive or dominant variance was quite difficult due to the small number of AA homozygous sows. The calculation model yielded a significant effect (P&lt;0.05) as well as tendency (P&lt;0.1) for the mentioned effects except for age at first farrowing.

Estimation of Genetic Parameters for Direct and Maternal Effects on Litter Size and Teat Numbers in Korean Seedstock Swine Population

The objective of this study was to estimate genetic parameters for total number of born (TNB), number of born alive (NBA) and teat numbers (TN) of Landrace and Yorkshire breeds in Korean swine population using multiple trait animal model procedures. Total numbers of 4,653 records for teat numbers and 8,907 records for TNB and NBA collected from 2004 to 2008 on imported breeding pigs and their litter size records were used in this study. To find the appropriate model for estimation of genetic parameters (heritabilities and genetic correlations), five statistical models (two models for reproductive traits, two models for teat numbers, one model for combining these traits) considering only direct additive genetic effects, including maternal effects were used and Akaike information criteria (AIC) of each two models for reproductive traits and teat trait were compared. The means and standard deviations of TNB, NBA, and TN were <TEX>$11.52{\pm}3.34$</TEX>, <TEX>$10.55{\pm}2.96$</TEX> and <TEX>$14.30{\pm}0.83$</TEX>, respectively. Estimated heritabilities for TNB and NBA traits using the model which considered only additive genetic effect were low (0.06 and 0.05, respectively). However, estimated heritabilities considering maternal genetic effects were a little bit higher than that of the model considering only additive genetic effect (0.09 for TNB and NBA, respectively). Estimated heritability for TN using the model which considered only additive genetic effect was 0.40. However, estimated heritability of direct genetic effects from a model considering maternal genetic effect was high (0.60). All results of AIC statistics, the models considering maternal effect was more appropriate than the models considering only additive genetic effect. Genetic correlations of direct additive genetic effect between litter size (TNB, NBA) and teat numbers were low (-0.18 and -0.14, respectively). However, genetic correlations of maternal effect between litter size (TNB, NBA) and teat numbers were a little bit higher than those of direct additive genetic effect (0.08 and 0.16, respectively).

Associations between Alu I Polymorphism in the Prolactin Receptor Gene and Reproductive Traits of Slovak Large White, White Meaty and Landrace Pigs

We investigated the effect of the prolactin receptor gene (PRLR) on total number of born (TNB), number of born alive (NBA) and number of weaned (NW) piglets in Large White (LW), White Meaty (WM) and Landrace (L) sows from six Slovak breeding farms. The frequency of A allele was 0.48, 0.49 and 0.47 in LW, WM and L, respectively. We found numerous highly significant effects of PRLR locus on TNB (; ) in all tested breeds. The most marked difference of + was found between AA and BB genotypes in WM. Within the other breeds the difference between the homozygous genotypes reached up to + and + pigs per litter in LW and L, respectively. We also identified significant differences between AA and AB genotypes related to TNB in L. Similarly NBA, as well as NW traits were significantly affected (; ) by the genotype just in LW and L. The homozygous genotype AA was favourable in all breeds and traits. Our results showed the possibility of PRLR utilization in marker-assisted selection within breeding programs to increase reproductive traits of pigs in Slovakia.

Evaluation of the effect and profitability of gene-assisted selection in pig breeding system

To evaluate the effect and profitability of using the quantitative trait loci (QTL)-linked direct marker (DR marker) in gene-assisted selection (GAS). Three populations (100, 200, or 300 sows plus 10 boars within each group) with segregating QTL were simulated stochastically. Five economic traits were investigated, including number of born alive (NBA), average daily gain to 100 kg body weight (ADG), feed conversion ratio (FCR), back fat at 100 kg body weight (BF) and intramuscular fat (IMF). Selection was based on the estimated breeding value (EBV) of each trait. The starting frequencies of the QTL's favorable allele were 0.1, 0.3 and 0.5, respectively. The economic return was calculated by gene flow method. The selection efficiency was higher than 100% when DR markers were used in GAS for 5 traits. The selection efficiency for NBA was the highest, and the lowest was for ADG whose QTL had the lowest variance. The mixed model applied DR markers and obtained higher extra genetic gain and extra economic returns. We also found that the lower the frequency of the favorable allele of the QTL, the higher the extra return obtained. GAS is an effective selection scheme to increase the genetic gain and the economic returns in pig breeding.

Association with litter size of new polymorphisms on ESR1 and ESR2 genes in a Chinese-European pig line

The objective of this study was to search for polymorphisms in the coding region of the estrogen receptors 1 and 2 (ESR1 and ESR2 )and to analyze the effects of these variants and the well known intronic ESR1 Pvu II polymorphism on litter size in a Chinese-European pig line. We identified five silent single nucleotide polymorphisms (SNP) in the ESR1 cDNA: c.669T > C (exon 3), c.1227C > T (exon 5), c.1452C > T (exon 7), c.1665T > C and c.1755A > G (exon 8). One pair of these SNP (c.1665T > C and c.1755A > G) co-segregated in the analyzed line, and the SNP c.669T > C showed the same segregation pattern as the Pvu II polymorphism. These polymorphisms were tested in this study, although the c.1452C > T SNP within exon 7 was not analyzed due to its low informativeness. In the ESR2 cDNA, one missense SNP was found within exon 5, which caused an amino acid substitution in the coded protein: "c.949G > A (p.Val317Met)" and was tested on sow litter size. Information on 1622 litter records from 408 genotyped sows was analyzed to determine whether these SNP influenced the total number of piglets born (TNB) or the number of born alive (NBA). The polymorphisms ESR1: [Pvu II; c.669T > C], ESR1: [c.1665T > C; c.1755A > G] and ESR2: c.949G > A showed no statistically significant association with litter size. However, the ESR1: c.1227T allele was significantly associated with TNB. The additive substitution effect was estimated to be 0.40 piglets born per litter (P < 0.03), and no dominance effects were observed. This SNP could be useful in assisted selection for litter size in some pig lines, as a new genetic marker in linkage disequilibrium with the causative mutation.

Association with litter size of new polymorphisms on ESR1 and ESR2 genes in a Chinese-European pig line

The objective of this study was to search for polymorphisms in the coding region of the estrogen receptors 1 and 2 (ESR1 and ESR2 )and to analyze the effects of these variants and the well known intronic ESR1 Pvu II polymorphism on litter size in a Chinese-European pig line. We identified five silent single nucleotide polymorphisms (SNP) in the ESR1 cDNA: c.669T > C (exon 3), c.1227C > T (exon 5), c.1452C > T (exon 7), c.1665T > C and c.1755A > G (exon 8). One pair of these SNP (c.1665T > C and c.1755A > G) co-segregated in the analyzed line, and the SNP c.669T > C showed the same segregation pattern as the Pvu II polymorphism. These polymorphisms were tested in this study, although the c.1452C > T SNP within exon 7 was not analyzed due to its low informativeness. In the ESR2 cDNA, one missense SNP was found within exon 5, which caused an amino acid substitution in the coded protein: "c.949G > A (p.Val317Met)" and was tested on sow litter size. Information on 1622 litter records from 408 genotyped sows was analyzed to determine whether these SNP influenced the total number of piglets born (TNB) or the number of born alive (NBA). The polymorphisms ESR1: [Pvu II; c.669T > C], ESR1: [c.1665T > C; c.1755A > G] and ESR2: c.949G > A showed no statistically significant association with litter size. However, the ESR1: c.1227T allele was significantly associated with TNB. The additive substitution effect was estimated to be 0.40 piglets born per litter (P < 0.03), and no dominance effects were observed. This SNP could be useful in assisted selection for litter size in some pig lines, as a new genetic marker in linkage disequilibrium with the causative mutation.

Effect of the estrogen receptor (&amp;lt;i&amp;gt;ESR&amp;lt;/i&amp;gt;) and ryanodine receptor (&amp;lt;i&amp;gt;RYR1&amp;lt;/i&amp;gt;) genes on reproductive traits of Slovak Large White, White Meaty and Landrace pigs (short communication)

Abstract. We investigated the effect of the estrogen receptor (ESR) and ryanodine receptor (RYR1) genes on total number of born (TNB), number of born alive (NBA) and number of weaned (NW) piglets in Large White (LW), White Meaty (WM) and Landrace (L) sows from six Slovak breeding farms. We found a significant effect of ESR locus on NW (P≤0.01) in LW, however, we observed a negative effect of BB genotype on the trait. In WM, positive associations of B allele with TNB, NBA, NW were found but the differences were not confirmed statistically. A highly significant effect (P≤0.01) of ESR locus on TNB (+0.62±0.18 pigs per copy of B allele), NBA (+0.65±0.18) and NW (+0.51±0.16) was identified in L breed. With RYR1 gene we found significantly higher TNB and NBA in heterozygous WM sows (+1.01±0.36 in TNB; +0.87±0.32 in NBA; P≤0.01). NBA was also significant in LW (+0.41±0.19; P≤0.05).

Analysis of properdin (BF) genotypes associated with litter size in a commercial pig cross population

Properdin (BF) was investigated as a candidate gene influencing litter size in a commercial pig cross population. The BF gene was chosen because of its integral role in influencing uterine epithelium growth and because several quantitative trait loci (QTL) with impact on reproductive traits have been detected near the centromere of porcine chromosome 7. A total of 123 F2 (Large White x Landrace) x Leicoma sows were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The sows were divided into two extreme performance groups, one with a high litter size (n = 61, > or = 14.3 piglets per litter) and the other with a low litter size (n = 62, < or = 11.3 piglets per litter). Although genotype and allele frequencies were uneven with 2.4% (AA), 16.3% (AB), 81.3% (BB) and 0.11 (A): 0.89 (B), the allele A was the unfavourable one, leading to less offspring. With regard to the level of significance at p < 0.05, the total number of born (TNB) and number of born alive (NBA) piglets were associated with BF genotypes. The genotype AA led to 10.55 TNB and 10.00 NBA, whereas the genotype BB led to 13.19 TNB and 12.11 NBA. The genotype AB was intermediate. In future, a systematic mating test is necessary in order to obtain more balanced genotype frequencies. Furthermore, it should be taken into consideration that the investigated polymorphism is located in an intronic region and the causative mutation is not clear yet.

Effect of the oestrogen receptor (ESR) gene on reproductive traits of Large White, White Meaty and Landrace pigs

We investigated the effect of oestrogen receptor (ESR) gene on total number of born (TNB), number of born alive (NBA) and number of weaned (NW) piglets in Large White (LW), White Meaty (WM) and Landrace (L) sows from six Slovak breeding farms. Detection of ESR (Pvu II) genotypes was performed by the PCR-RFLP method. The frequencies of favourable B allele in LW, WM and L were 0.33, 0.25 and 0.08, respectively. We found a highly significant effect of ESR locus on NW (P &amp;le; 0.01) in LW, however, we observed a negative effect of BB genotype on the trait. In WM, a positive association of B allele with TNB, NBA and NW was found but the differences were not confirmed statistically. A highly significant effect of ESR locus on TNB, NBA and NW (P &amp;le; 0.01) was identified only in L breed. We found an increase of +0.62 &amp;plusmn; 0.18 (TNB), +0.65 &amp;plusmn; 0.18 (NBA) and +0.51 &amp;plusmn; 0.16 (NW) pigs per copy of B allele. &amp;nbsp;

Yorkshire종 돼지에서 PCR-RFLP을 이용한 Estrogen Receptor의 유전적 다형과 산자수간의 관련성

본 연구는 PvuII PCR-RFLP를 이용하여 Yorkshire종 돼지에서 Estrogen Receptor의 유전적 다형과 산자수간의 관련성을 분석하기 위하여 수행되었다. 무창 돈사에서 사육중인 242두의 종빈돈으로부터 혈액을 채취하여 PvuII PCR- RFLP로 ER 유전자형을 결정하였다. ER 유전자 좌위에서 유전자 빈도는 각각 0.39(A)와 0.61(B)였다. ER 유전자형별 산자수에 대한 효과는 최소제곱평균을 설명하는 고정모형을 설정하여 추정하였다. 분석결과 복당 총산자수와 실산자수에서 특정 ER 대립유전자(B)에서 산자수 증진효과가 관찰되었다. 따라서 돼지 ER 좌위의 유전적 변이는 번식돈의 산자수 증대와 관련된 marker-assisted selection(MAS)에 응용될 수 있을 것으로 사료된다. This study was performed to investigate a possible association of the porcine estrogen receptor(ER) locus with the total number of born(TNB) and number of born alive(NBA) in Yorkshire pigs. Using DNAs extracted from 242 Yorkshire pigs, the ER genotype was determined by PvuII PCR-RFLP. The ER allele frequencies of two types of A and B were 0.39 and 0.61, respectively. The least squares means of the litter size by ER genotype was evaluated. The TNB and NBA were found to be associated with an specific ER allele. The genotype at the porcine ER locus has an application potential for marker-assisted selection for litter size in pigs.