Total Number Of Piglets Research Articles

Marine derived Ca-Mg complex supplementation basal diet during four subsequent parities improved longevity and performance of sows and their litters.

The aim of the present study was to evaluate the effects of dietary supplementation of Ca-Mg complex on the longevity and reproductive performance of sows. In total, seventy-two gilts ([Yorkshire × Landrace] × Duroc, average body weight 181 kg) were randomly allocated to 1 of 3 treatments during 4 successive parity in a 4 × 3 factorial arrangement. Treatments consisted of CON (basal diet), CM1 (basal diet -MgO - 0.3% limestone + 0.4% Ca-Mg complex), and CM2 (basal diet - MgO - 0.7% limestone + 0.4% Ca-Mg complex). A higher (p < 0.05) number of totals born and live piglets, and sows increased feed intake during gestation and lactation, increased backfat thickness, and increased estrus interval were observed (p < 0.05) during their third and fourth parity than during their first and second parity. Ca-Mg complex supplementation improved (p < 0.05) the number of total piglets during the first and second parity as well as live-born piglets during the first to third parity, reduction (p < 0.05) in backfat thickness during the third and fourth parity, a higher (p < 0.05) initial and final number of suckling piglets as well as higher weaning weight compared with sows fed CON diet during the first, second, and third parity. The average daily gain (ADG) was higher (p < 0.05) in piglets born to CM1 and CM2 sows regardless of parity. The treatment diets fed to sows lowered (p < 0.05) the duration of first to last piglet birth and placenta expulsion time compared with CON sows. A significant interactive effect (p = 0.042) between parities and treatment diets was observed for the first to last piglet birth. Thus, Ca-Mg complex supplementation by partially replacing limestone in the basal diet enhanced sow performance, specifically during their third and fourth parity, thereby improving sow longevity.

Machine learning based personalized promotion strategy of piglets weaned per sow per year in large-scale pig farms

BackgroundThe purpose of this study was to analyze the relationship between different productive factors and piglets weaned per sow per year (PSY) in 291 large-scale pig farms and analyze the impact of the changes in different factors on PSY. We chose nine different algorithm models based on machine learning to calculate the influence of each variable on every farm according to its current situation, leading to personalize the improvement of the impact in the specific circumstances of each farm, proposing a production guidance plan of PSY improvement for every farm. According to the comparison of mean absolute error (MAE), 95% confidence interval (CI) and R2, the optimal solution was conducted to calculate the influence of 17 production factors of each pig farm on PSY improvement, finding out the bottleneck corresponding to each pig farm. The level of PSY was further analyzed when the bottleneck factor of each pig farm changed by 0.5 standard deviation (SD).Results17 production factors were non-linearly related to PSY. The top five production factors with the highest correlation with PSY were the number of weaned piglets per litter (WPL) (0.6694), mating rate within 7 days after weaning (MR7DW) (0.6606), number of piglets born alive per litter (PBAL) (0.6517), the total number of piglets per litter (TPL) (0.5706) and non-productive days (NPD) (− 0.5308). Among nine algorithm models, the gradient boosting regressor model had the highest R2, smallest MAE and 95% CI, applied for personalized analysis. When one of 17 production factors of 291 large-scale pig farms changed by 0.5 SD, 101 pig farms (34.7%) can increase 1.41 PSY (compared to its original value) on average by adding the production days, and 60 pig farms (20.6%) can increase 1.14 PSY on average by improving WPL, 45 pig farms (15.5%) can increase 1.63 PSY by lifting MR7DW.ConclusionsThe main productive factors related to PSY included WPL, MR7DW, PBAL, TPL and NPD. The gradient boosting regressor model was the optimal method to individually analyze productive factors that are non-linearly related to PSY.

Reproductive qualities of sows of different breeding levels.

Reproductive qualities of sows of different breeding levels.

Productivity of sows and growth of piglets during the use of different indoor microclimate systems

The aim of the article was to study the dependence of reproductive qualities of sows of Irish origin and growth intensity of their piglets on the influence of technological and design parameters of the microclimate system in the farrowing room. The material of the study was the F 1 sows of the Hermitage Genetics maternal line, which were reared in two sections for farrowing of identical planning, identical construction execution and engineering and technical support, except for the microclimate creation and maintenance systems installed in them. The sows of the control group were kept under the classical valve-type ventilation system, and the sows of the experimental group were kept under the geothermal ventilation system. The analysis of reproductive indicators of the experimental population was carried out using generally accepted statistical methods, one way analysis of variance, evaluation index for a limited number of traits, selection index of reproductive qualities of sows. At the end of the experiment and based on the evaluation of data, it was found that the productivity of sows whose farrowing took place in rooms with geothermal microclimate system, were significantly higher during the study period in the number of piglets at weaning – by 0.70 heads or 5.58% (p ≤ 0.001), their safety – by 4.49% (p ≤ 0.05) and the weight of the nest at weaning – by 2.91 kg or 4.23% (p ≤ 0.05) relative to peers kept in sections for farrowing with the classic valve type of microclimate system. The method of factor analysis of variance allowed to identify a statistically significant effect of the type of microclimate system on these indicators, namely: the number of piglets at weaning with an impact force of 2.01%, the safety of piglets – with an impact force of 2.03% and on the weight of the nest of piglets at weaning – with a force of influence within 2.01%. The results of the evaluation of the reproductive qualities of pigs showed the predominance of livestock kept under geothermal ventilation, both for the use of the evaluation index – by 1.31 points, and for the use of the selection index of reproductive qualities – by 1.33 points. No statistically significant difference between sows and piglets kept under different microclimate systems on indicators such as total number of piglets at birth, number of stillborn piglets, proportion of stillborn piglets, fertility, high fertility, weight of one head at weaning, absolute gain, average daily yield has not been established. Key words: sow, piglets, microclimate system, farrowing, piglet nest weight, safety.

Estimates of repeatability for reproductive traits in Large White sows

The main aim of this paper was to analyze the effect of parity number on the litter size and other reproductive traits in Large White sows during successive farrowings to determine the repeatability estimates. The population used for the present study is from a pig farm managed by the Limited Liability Company (LLC) “Tavriys’ki svyni” 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 estimation of reproductive performance was conducted for each animal included in this study. The total number of piglets born (TNB), number piglets born alive (NBA), number weaned piglets (NW), number of stillborn piglets (NSB) and frequency of stillborn piglets (FSB) per litter, number of piglets that died between birth and weaning (NPWM) and frequency of piglets that died between birth and weaning (FPWM) per litter were monitored in the first eight parities in the period of eleven years (2007–2017). For TNB, of the 28 correlations between different parities, 19 (i.e., 68 %) were statistically significant (P &lt; 0.001…0.05). The correlation between TNB values at repeated farrowings was, as expected, positive and in most cases moderate, from 0.197 (between 1st and 4th parity) to 0.365 (between 6th and 7th parity). Highest significant correlation was determined between TNB values in four latest farrowings (5th–8th parities). For NBA, only 7 (i.e., 25 %) phenotypic correlations were statistically significant (P &lt; 0.002…0.025) and varied from 0.230 (between 1st and 8th parity) to 0.303 (between 6th and 7th parity). Finally, for NW only 5 (i.e., 18 %) phenotypic correlations were statistically significant (P &lt; 0.005…0.05) and varied from 0.200 (between 3th and 7th parity) to 0.281 (between 4th and 6th parity). Thus, while observing the phenotypic correlations for the same studied traits between different parities (P1–P8), it can be seen that the correlations for TNB are positive and stronger compared to the phenotypic correlations for NBA and NW. For all studied litter size traits, the weakest relationship was found between the first four farrowings (1st–4th parity) and more stronger correlation was found between the latest four farrowings (5th–8th parity). The repeatability estimates for the LW sow’ litter size traits were generally low, 0.217 ± 0.037, 0.141 ± 0.032 and 0.073 ± 0.027 for TNB, NBA and NW, respectively, indicating that most of the phenotypic variance is explained by other factors than sows’ variance (primarily, by environmental factors). In addition these results indicate that the repeatability estimates for TNB were higher than for NBA, and the repeatability estimates for NBA were higher than for NW. This may be due in part to the gain of the permanent environmental effect on the number of stillborn piglets and the high rate of pre-weaning mortality for later parities.

Associations between testicular development and fetal size in the pig

BackgroundImpaired reproductive performance is the largest contributing factor for the removal of boars from commercial systems. Intrauterine growth restricted piglets represent 25% of the total number of piglets born and have impaired reproductive performance. This study aimed to improve the understanding of temporal changes in testicular gene expression during testes development in fetuses of different size. The lightest and closest to mean litter weight (CTMLW) male Large White × Landrace littermates were collected at gestational days (GD) 45, 60 and 90 (n = 5–6 litters/GD).ResultsTestes weight and testes weight as a percentage of fetal weight were not associated with fetal size at GD60 or 90. Fetal plasma testosterone was not associated with fetal size at GD90. There was no association between fetal size and seminiferous tubule area and number, number of germ or Sertoli cells per tubule. The lightest fetuses tended to have wider seminiferous tubules compared to the CTMLW fetuses at GD90 (P = 0.077). The testicular expression of KI67 (P ≤ 0.01) and BAX:BCL2 ratio (P = 0.058) mRNAs decreased as gestation progressed. Greater SPP1 mRNA expression was observed at GD60 when compared with GD45 and 90 (P ≤ 0.05). Lower expression of DMRT1 and SPP1 (P < 0.01) mRNAs was observed in testes associated with the lightest fetuses compared to the CTMLW fetuses at GD90.ConclusionsThese findings provide novel insights into the expression profiles of genes associated with testicular development and function. Further, these data suggest that programming of reproductive potential in IUGR boars occurs late in gestation, providing a platform for further mechanistic investigation.

Reproductive traits of sows with different duration of feeding of biologically active additives in their diet

The addition to the main diet of sows of additional trace elements (copper, zinc, cobalt, manganese) 10–50 mg/kg of live weight, vitamin B₉ (folic acid) 35 mg/head. and Hexavit 196 mg/ head/day is the most effective in comparison with its use during the last third of pregnancy. The highest effect was obtained of all the compared groups when using a combination of trace elements with Hexavit and all the studied additives together. At the same time, the cobalt content in the blood of sows of these groups has been decreased by 3,3 and 5,0 times, and manganese by 2 times. In the first half of pregnancy, the addition of folic acid against the background of trace elements in the diet of sows had a more positive effect on individual indicators of metabolic metabolism in comparison with other groups. However, in the last third of pregnancy, the best results were observed in the group with Hexavit: the total protein content increased by 3,8 %, urea decreased by 57,6 (P ≤ 0,001), glucose increased by 25,1 %. The feed additive of trace elements and folic acid in the diet of sows in comparison with the control group increased the total number of piglets in the litter by 10,2 %, trace elements and Hexavit by 22,0, with their total use by 18,6 % (P ≥ 0,05), and the number of live piglets by 7,1 %, 9,1 and 15,2 %, respectively. At the same time, the consumption of compound feed, energy and protein per piglet decreased by 6,6 %, 16,1 and 13,2 %, respectively. The use of vitamin and mineral additives with Hexavit in the diet of sows in the last third of pregnancy, as well as with the addition of folic acid, increased the number of newborn piglets by 6,3 %, and live piglets by 2,6 and 1,8 %, respectively. Folic acid alone with trace elements did not have the positive effect on the reproductive traits of sows.

Correlations between microsatellite DNA heterozygosity and reproductive traits in Large White sows

The main aim of this paper was to determine whether heterozygosity (assessed using microsatellite genotypes) was correlated with the reproductive traits in sows. The study was conducted on two herds of sows of the Large White sows breed at the Limited Liability Company “Tavriys’ki svyni” (Kherson region, Ukraine) and the Agricultural Private Enterprise “Techmet-Yug” (Mykolayiv region, Ukraine). During the study, we used eleven microsatellite loci recommended by International Society for Animal Genetics (ISAG) – S0101, S0155, S0228, S0355, S0386, Sw24, Sw72, Sw240, Sw857, Sw936 and Sw951. The litter records included information on the total number of piglets born (TNB), number of piglets born alive (NBA), number of stillborn piglets (NSB), frequency of stillborn piglets (FSB), litter size at weaning (NW) in the first five parities. Individual heterozygosity estimates (for each microsatellite loci separately) and microsatellite multilocus heterozygosity (for all used loci) estimates (MLH) were used in our analysis. ANOVA was used to determine the relationship of the dependent effects (reproductive traits) to single locus heterozygosity using two classes: 0 (for homozygous individuals) and 1 (for heterozygous individuals). In addition, the following indicators were calculated for each genotype: the squared distances (d2) between alleles within an individual for each microsatellite loci and mean squared distances (mean d2) between alleles within an individual for 11 microsatellite loci. Spearman’s rank correlation coefficients were used to measure the association between d2 (for each microsatellite loci) and reproductive traits in sows. ANOVA on reproductive traits of sows belonging to different MLH and mean d2 classes was also undertaken. For sows from the Agricultural Private Enterprise “‘Techmet-Yug” were observed negative associations between heterozygosity and reproductive traits. We conclude that care should be taken when crossing between different breeders (English and Hungarian selection) to avoid outbreeding depression.

Utilization and reproductive performance of gilts in large-scale pig farming system with different production levels in China: a descriptive study

BackgroundThis study was to investigate the utilization and reproductive performance of gilts in large-scale pig farms. Data of this descriptive study included 169,013 gilts of 1540 gilts’ batches on 105 large-scale pig farms from April 2020 to March 2021. According to the upper and lower 25th percentiles of piglets weaned per sow per year (PSY) during the research stage, pig farms were divided into three productivity groups: high-performing (HP), intermediate-performing (IP) and low-performing (LP) farms. On the basis of breeds, LP (LP-Total) farms was further divided into LP-breeding pig (LP-BP) and LP-commercial pig (LP-CP) groups. Average utilization, estrus and first mating data was collected from a total of 1540 gilts’ batches. The age-related factors (introduction age, age at first estrus and age at first mating) and litter production (total number of piglets, number of piglets born alive and number of weaned piglets, as well as their proportion distribution) among HP and LP groups were compared. The litter production in different age groups were also analyzed.ResultsThe introduction age, mortality and culling rate of HP farms were lower compared with LP farms. Total number of piglets per litter, number of piglets born alive per litter and number of weaned piglets per litter in HP farms were significantly more than those of LP groups, respectively. The proportion distribution peaks of litter production in HP farms were shifted about two more than those in LP groups, respectively; and the proportion of low litter production (eight per litter or less) was lower than that in LP groups. The results of different age groups showed that total number of piglets per litter and number of piglets born alive per litter in 220–279 d were the most, while that of 370 d was the least.ConclusionsThe overall utilization and reproductive performance of gilts in HP farms was better than those of LP farms. The difference in utilization was reflected in introduction source, culling rate and mortality. While the age at first estrus and first mating, breeds and litter production were the main differences for reproductive performance.

PSXV-9 Transgenerational epigenetic variance for production and reproduction traits in maternal-line pigs

Abstract Modeling epigenetic factors impacting phenotypic expression of economically important traits has become a hot-topic in the field of animal breeding due to the variability in genetic expression caused by environmental stressors (e.g., heat stress). This variability may be due, in part, to in-utero epigenomic remodeling, which has been reported to be passed from parent to offspring. We aimed to estimate transgenerational epigenetic variance for various production and reproduction traits measured in a maternal-line pig population, using a Bayesian approach. The phenotypes for production [n = 10,862; i.e., weaning weight (WW), birth weight (BW) and ultrasound-backfat thickness (BF)] and reproduction [n = 5,235, i.e., number of piglets born alive (NBA) and total number of piglets born (TB)] traits from a purebred Landrace population were provided by Smithfield Premium Genetics (NC, USA). The pedigree information traced back to 10 generations. Single-trait genetic analyses were performed using mixed models that included additive genetic, common environmental, and epigenetic random effects. The Gibbs sampler algorithm based on Markov chain Monte Carlo was used to estimate the variance components. The epigenetic relationship matrix was constructed using a recursive parameter (λ) related to the transmissibility coefficient of epigenetic markers. A grid search approach was used to define the optimal λ value (λ values ranged from 0.1 to 0.5, with an interval of 0.1). The optimal λ value was determined based on the deviance information criterion, and it was used to estimate the additive and epigenetic variances. For instance, based on preliminary results, the optimal λ value estimated for TB was 0.3 with an additive genetic variance of 0.94 (0.19 PSD) and epigenetic variance of 0.67 (0.18 PSD). The additive genetic heritability was 0.076 (0.015 PSD) and the estimated epigenetic heritability was 0.053 (0.015 PSD). This preliminary result suggests that epigenetics contribute to the non-Mendelian variability in pigs.

PSVI-8 Effects of a mycotoxin deactivator on performance of gestating and lactating gilts fed diets containing added mycotoxins

Abstract The present study aimed to evaluate the impact of a mycotoxin deactivator in diets containing added mycotoxins for gestating and lactating gilts on their performance. A total of 60 gilts (LD x LW) were used. After insemination the gilts were distributed among 3 dietary treatments according to a randomized block design: a negative control (CON); mycotoxin positive control (Myc); and a positive control added a mycotoxin deactivator (Myc+Deact 2 kg/ton; Unike®Plus, Adisseo). The total mycotoxins levels added to the diets 2 and 3 from d 75 of gestation until farrowing were: DON at 2.5 mg/kg, FBs at 10 mg/kg, and ZEA at 0.75mg/kg. Sows received the experimental diets from d 75 of gestation until weaning (i.e. 21 d). At farrowing, total number of piglets born, born alive, stillborn, and mummies were measured. Piglets were individually weighed 24-h post-farrowing, and at weaning to determine litter performance during lactation. The effects of diet composition, blocks and initial weight were tested according to a general linear procedure analysis of variance (GLM procedure of SAS). During gestation, treatments influenced (P = 0.022) sow mortality rate: CON had no mortality and Myc 15.8% and Myc+deact 10.5%. Same observation was made for the lactation period (P = 0.017): CON showed a lower mortality rate compared to the mycotoxin fed sows (5.0 vs. 31.2 vs. 11.8%, respectively for CON, Myc and Myc+deact). Sow milk production yield was greater (P = 0.021) in CON (11.66 vs. 9.53 vs. 9.67 kg/ d, respectively for CON, Myc and Myc+deact). As a consequence of that, treatments also influenced piglet (P = 0.047) and litter (P = 0.048) weight with a higher value for CON sows, followed by Myc+deact and Myc. Our findings showed that the use of the deactivator can mitigate the negative effects on performance when animals are subjected to diets contaminated by challenging levels of mycotoxins.

Polymorphism of Selected Microsatellite Markers against Breeding Performance Indexes of Polish Large White and Polish Landrace Sows

The study aimed to analyze 12 microsatellite markers located in the areas of quantitative trait loci related to litter size in 82 sows, including 45 Polish Large White and 37 Polish Landrace sows, kept on a farm in southwest Poland. Breeding documentation provided data on the total number of piglets born per litter and the numbers of live-born, stillborn and weaned piglets; the corresponding percentage values were also calculated. DNA isolation was performed from 15–20 hairs taken from live animals, and the markers used in the research were divided into four multiplexes. The influence of genotype at a given locus on the reproductive traits was analyzed only for genotypes represented by at least five animals. The results of the analyses for all the sows (treated as the maternal component and not as distinct breeds) showed statistically significant (p ≤ 0.05) differences between the genotypes and the values of the analyzed traits for markers S0008, SW160, SW245, SW714, SW1125 and SW2411. Among these markers, the breed-dependent analysis also showed significant differences in the Polish Large White breed for markers S0008, SW160 and SW1125, and in the Polish Landrace breed for SW245. Additionally, the breed-dependent analysis found significant differences in markers SW903 and SW1808 for the Polish Large White sows, and S0064, SW472 and SW903 in Polish Landrace sows. SW903 was the only marker for which differences in the analyzed reproductive traits differed between genotypes in both breeds (still analyzed separately), although in terms of different traits. The above results indicate the usefulness of microsatellite markers in researching the differentiation of litter size indicators. Although both breeds belong to the maternal component, they showed significant differences in terms of markers. This may suggest difficulties in finding universal (that is, working well for various breeds of the maternal component) markers, indicating the need to look for breed-specific markers, something that calls for further research into numerous animals.

Age dynamics of reproductive qualities of sows depending on the duration of the suckling period

The article studied the influence of sows' age on their reproductive qualities at the traditional - 28 days and shortened - 21 days duration of the suckling period. It was found that the total number of piglets born increased from the second reproductive cycle to the sixth inclusive. With the traditional duration of the suckling period, the most significant growth was observed during the third, fourth and fifth farrowing (8.0-8.6%), while with a reduced duration of the suckling period, it was significantly lower (3.8-4.9%). and lasted from the third to the fifth reproductive cycle. As sows' reproductive age increased, their fertility increased. Its highest growth in both terms of weaning of piglets was on the third farrowing and then gradually decreased. Sows with a reduced suckling period had a lower increase in fertility throughout reproductive life. The nest weight of piglets at birth increased until the third farrowing and then gradually decreased. With the traditional duration of the suckling period, the intensity of the increase in the nest weight of piglets born at the age of sows is higher compared to analogues in which the lactation period was reduced. Preservation of piglets in sows' nests deteriorated with increasing reproductive age. It worsened less intensely in sows with a reduced suckling period. The number of weaned piglets depended to a greater extent on the age of the sows and to a lesser extent on the length of the suckling period. From the third farrowing, it constantly decreases with increasing age of the sow, regardless of the length of the suckling period. The average weight of one piglet increases with the age of sows from the third farrowing, and its growth is more intense with a reduced duration of lactation. The increase in the weight of the nest of piglets at weaning is most significant for 3-5 farrowings, after which there was a decrease in this indicator for both periods of weaning piglets. A comprehensive assessment of the reproductive quality of sows using indices confirms the increase in sow productivity during the second - fourth reproductive cycle with a gradual decrease during the fifth to sixth farrowing, both in the traditional and reduced duration of the suckling period. It is proved that the sow age factor determines the probable influence on the number of piglets at weaning (9.43 %), their safety (5.56 %), the weight of the nest of piglets at weaning (1.87 %) and fertility (1.65 % ). While the suckling period factor affected the nest weight of piglets at weaning with a force of 28.49 %, the number of piglets at weaning with a force of 0.62 %, the safety of piglets before weaning at 0.19 % and did not affect the fertility of sows. Key words: sow, reproductive cycle, duration of lactation, fertility, safety, piglet.

Analysis of the stillborn piglet’s distribution in the Large White sows

The main aim of this paper was to estimate the piglet stillbirth incidence distribution in the Large White (LW) sows. The population used for the present study is from a pig farm managed by the Limited Liability Company (LLC) “Tavriys’ki svyni” 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 estimation of reproductive performance was conducted for each animal included in this study. The total number of piglets born (TNB), number of stillborn piglets (NSB) and frequency of stillborn piglets (FSB) per litter were monitored in the first eight parities in the period of eleven years (2007–2017). The 800 farrowings averaged 11.3 piglets per litter. Of the 9037 piglets born, 7895 were live born and 1142 were stillborn. Stillborn pigs were observed in 63.3 ± 1.7 % of the litters and the pig stillbirth incidence was 12.6 ± 0.4 %. The percentage of pigs born dead in total pigs born, obtained in this study is within the range of rates (5 to 15 %) reported for commercial pig farms in other countries. The frequencies of litters with 1, 2, 3, 4 and 5 or more stillborn piglets were 27.1, 14.8, 10.6, 5.8 and 5.0 %, respectively. The frequency of litters with at least one stillborn piglet varied from 44 % (2nd parity) to 76 % (6th parity). Significant factor in the analysis for frequency of litters with at least one stillborn piglet was parity number in sow (Chi-squared test: χ2 = 51.35; df = 7; P &lt; 0.001). This frequency increased as parity number in sow increased (Pearson correlation coefficient: r = 0.929; P &lt; 0.01). We noted that the piglet stillbirth incidence in the LW sow’s litter took place already during the first farrowing for almost half of the sows (46%). In general, this distribution is well approximated by the exponential model equation (y = 73.567*exp(-0.551x); R2 = 97.09 %). The LW sows with stillborn piglets in four out of eight farrowings were the most reported. The value of the entropy of the traits NSB and FSB varied significantly among sows of different parities (Chi-squared test: in both cases P &lt; 0.001). At the same time, a significant increase in the entropy estimates for both traits from the 1st parity to the 8th parity was noted (Spearman's rank correlation: P &lt; 0.001…0.002).

Influence of the reproductive cycle on the zootechnical indexes in hyperproliferous swine matrices

In swine breeding stock, the calving order has a direct correlation with the performance of the litter, both at birth and at weaning. Thus, the present study aimed to evaluate the effect of the number of reproductive cycles of swine females on their zootechnical indexes. Forty healthy swine females from an industrial cross (Landrace X Large White) were used, distributed in five treatments, eight females per treatment, submitted to the same type of diet and water ad libitum. Being carried out the management of confirmation of pregnancies or return to heat and transfer to maternity After calving, productive indexes of females and piglets were evaluated. The data obtained were analyzed through analysis of variance, and comparison of means by the Tukey test (p &lt;5%). In alternative cases, the chi-square test was performed. There was an increase in the number of piglets born total and live births up to the third cycle, followed by a drop in the fourth and fifth cycle. There was no difference between treatments in relation to piglet weight at birth, weaning and mummified rate. However, there was a relationship between the number of births, the rate of stillbirths, deaths from crushing and repetition of heat, showing a reduction in such rates due to the advancing age of the mothers. Thus, the results demonstrated that the total number of piglets born and live births increases while losses due to stillbirth, crushing and repetition of heat tend to decrease with advancing age of the females, with greater reproductive efficiency achieved between the third and fourth cycle.

A 10-year trend in piglet pre-weaning mortality in breeding herds associated with sow herd size and number of piglets born alive

BackgroundPiglet pre-weaning mortality (PWM) is one of the biggest problems regarding sow performance and piglet welfare. Recently, PWM has increased in some countries, but it is not known if there are similar increases in other countries, nor whether increased PWM is related to either increased numbers of piglets born alive (PBA) or to sow herd size. So, the objectives of the present study were 1) to explore the trend in PWM in Spanish sow herds over a recent 10-year period, along with related measurements such as PBA, stillborn piglets, herd productivity and herd size; and 2) to examine the relationships between PWM and the related measurements.MethodsHerd-level annual data from 2007 to 2016 for 91 herds in Spain were abstracted from a sow database compiled by a veterinary consultancy firm that asked client producers to mail data files on a regular basis. The database software automatically calculated herd-level PWM (%) as follows: the total number of piglets born alive to a sow completely weaned during a year (TPBA) minus the total number of piglets weaned by the completely weaned sow during the year divided by TPBA × 100. All the statistical analyses were performed by using SAS University Edition. A growth curve model was applied to incorporate correlations for all of the observations arising from the same farm.ResultsOver the 10 years, herd means of PWM (standard deviation) increased from 11.9 (4.1) % to 14.4 (3.2) %, and mean PBA increased by 1.9 pigs. Mean age of piglet death during lactation increased by 3.8 days, and later years were significantly associated with herd size and the number of piglets weaned per sow per year (PSY; P < 0.05). Higher PWM was associated with more PBA, more stillborn piglets and small-to-mid herds (lower than the median size: < 570 sows; P < 0.05). Also, there was a significant interaction between the herd size groups and PBA for PWM (P < 0.05): as PBA increased from 9 to 14 pigs, PWM increased by 9.6% in small-to-mid herds, compared with an increase of only 6.6% in large herds (> 570 sows). Furthermore, as PWM decreased from 18 to 8%, herd productivity measured as PSY increased by 2.2 pigs in large herds, compared with only 0.6 pigs in small-to-mid herds.ConclusionLarge herds were better than small-to-mid herds at alleviating the association between increased PBA and increased PWM. Also, the relationship between decreased PWM and increased herd productivity was improved more in large herds than in small-to-mid herds.

Factors affecting piglets stillbirth in Large White sows

This study considers signs of a sow that affect the stillborn piglets number in the nest and the likelihood of stillbirth. The animals that were used for this study were kept on the pig farm of «Tavriys’ki svyni» LLC, located in the Skadovsky district (Kherson region, Ukraine). The experimental materials used for this study consisted of 100 animals from productive parent sows of the Large White pig. The reproductive indicators of each animal included in this study were evaluated. The total number of piglets at birth (both live and dead), i.e. total litter size and and sow farrowing number were monitored for the first eight farrows during the period of eleven years (2007–2017). Stillborn piglets were observed in 63.3 ± 1.7% of litter, and their average proportion in the nest was 11.5 ± 0.4%. The proportion of piglets born dead of the total piglets at birth obtained in this study is within the range of 5 to 15%, which has been previously noted for commercial pig farms in other countries. With an increase in the age of the sow (the number of farrowing’s), there was a gradual decrease in the proportion of the litter in which no stillborn piglet was observed (χ2 = 51.35; P &lt; 0.001), and, conversely, the proportion of nests in which 2–4 stillborn piglets were recorded gradually increased (χ2 = 46.32; P &lt; 0.001). The number of stillborn piglets and the frequency of stillborn piglets in the litter tended to increase in sows that had a large litter size at birth (in both cases: P &lt; 0.001).The binary logistic regression analyses indicated that the probability of a piglet being stillborn was significantly associated with the farrowing number of the sow and the total number of piglets in the litter (χ2 = 155.00; P &lt; 0.001). This model predicted well the presence of at least one stillborn piglet per litter (in 86.6% of cases) and more or less adequately predicted its absence (in 42.9%). Our results indicate that there is a significant interaction between the number of farrowing and the total size of the litter when determining the estimate of the proportion of stillborn piglets in the litter. The same predicted estimates can be obtained for a small litter in an older sow, or, conversely, for a large litter in a first-farrowing sow.

PSV-15 Genomic basis of reproductive performance in PRRSV-infected sows

Abstract Previous studies have shown that reproductive traits in sows during porcine reproductive and respiratory syndrome (PRRS) outbreaks are lowly heritable. However, little is known about the genomic basis of reproductive performance in PRRS virus (PRRSV)-infected sows. Thus, the objective of this work was to evaluate the genomic basis of reproductive performance in PRRSV-infected sows. Farrowing data from 475 Duroc and 405 Landrace sows that experienced a PRRS outbreak were used. Heritability and genome-wide association studies (GWAS) based on ~30K SNP genotypes were performed for each breed separately, for number of piglets born alive (NBA), stillborn piglets (NSB), mummified piglets (NM), piglets born dead (NBD; NSB+NM), total number of piglets born (TNB; NBA+NBD), and piglets weaned (NW). Heritabilities were estimated with ASReml using a model with the fixed-effect of parity and an animal random-effect, using a genomic-relationship matrix. GWAS was performed using Bayes-B in GenSel with a model fitting parity as fixed-effect and SNP effects as random. Heritability estimates (± standard error) for NBA, NSB, NM, NBD, TNB, and NW were 0.07±0.07, 0.02±0.11, 0.04±0.10, 0.08±0.08, 0.08±0.07, 0.06±0.04, respectively, for Duroc, and 0.09±0.07, 0.10±0.07, 0.10±0.08, 0.11±0.07, 0.07±0.08, 0.07±0.08, respectively, for Landrace. For Duroc, GWAS identified a quantitative trait locus (QTL) on chromosome (chr) 3 [114-120 megabases (Mb)] explaining 3.9% of the genetic variance (GV) for NBA, on chr 13 (189-193 Mb) explaining 2.7% GV for NBD, and on chr 5 (36-41 Mb) explaining 4.3% GV for TNB. For Landrace, GWAS identified a QTL on chr 13 (154-162 Mb) explaining 12.8% GV for NBA, on chr 14 (59-69 Mb) explaining 2.5% GV for NBD, and on chr 10 (7-9 Mb) explaining 4.1% GV for NW. These results indicate that reproductive traits are lowly heritable during a PRRS outbreak with few QTL identified in Duroc and Landrace sows.

PSV-11 Accuracies of genomic prediction for reproductive traits in PRRSV-infected sows

Abstract Recent studies on host-genetics of response to porcine reproductive and respiratory syndrome virus (PRRSV) infection have shown that genetic markers can be used to predict performance in growing pigs. On the other hand, no work has been done on the genomic prediction of reproductive performance in PRRSV-infected sows. Thus, the objective of this work was to assess the accuracies of genomic prediction for reproductive traits in PRRSV-infected sows. A total of 475 Duroc and 405 Landrace sows with ~30K SNP genotypes had farrowing performance data during the outbreak on: number of piglets born alive (NBA), stillborn piglets (NSB), mummified piglets (NM), piglets born dead (NBD; NSB+NM), total number of piglets born (TNB; NBA+NBD), and piglets weaned (NW). Genomic prediction was performed by Bayes-B with a model fitting parity as fixed-effect and SNP effects as random. Analyses were performed for two scenarios: within-breed and between-breed. For the within-breed prediction, 4-fold cross-validation was used. For the between-breed prediction, all data for each breed were used. Accuracy of genomic prediction (AGP) was calculated as the correlation between genomic estimated breeding values and pre-adjusted phenotype, divided by square-root of heritability. For the within-breed prediction, AGP (± standard deviation) for NBA, NBD, NM, NSB, NW, and TNB were 0.24±0.05, 0.07±0.10, -0.27±0.06, -0.24±0.09, -0.05±0.05, 0.19±0.03, respectively, for Duroc, and 0.37±0.02, 0.38±0.11, 0.30±0.07, 0.60±0.10, 0.09±0.11, 0.15±0.10, respectively, for Landrace. For the between-breed prediction, AGP for NBA, NBD, NM, NSB, NW, and TB were 0.28, -0.17, -0.01, 0.37, 0.27, and 0.29, respectively, when training on Landrace and validating on Duroc, and 0.28, -0.14, 0.01, 0.15, 0.23, and -0.01, respectively, when training on Duroc and validating on Landrace. Results show that the accuracies of genomic prediction for reproductive traits during a PRRSV outbreak are low to moderate.

ОЗНАКИ ВІДТВОРЮВАЛЬНИХ ЯКОСТЕЙ СВИНОМАТОК РІЗНОЇ ЕКСПЛУАТАЦІЙНОЇ ЦІННОСТІ ТА РІВЕНЬ ЇХ ДИСКРЕТНОСТІ

Досліджено показники відтворювальних якостей свиноматок великої білої породи, зважаючи на їхню експлуатаційну цінність, розраховано рівень дискретності зазначеної групи ознак та економіч-ну ефективність результатів експерименту. Дослідження проведено в умовах племінного репродук-тора з розведення свиней великої білої породи СТОВ «Дружба-Казначеївка» Дніпропетровської обла-сті та лабораторії тваринництва Державної установи Інститут зернових культур НААН. Оцінку свиноматок великої білої породи за основними показниками рівня адаптації та відтворювальних яко-стей по групі (S) та сукупності загалом (σ) проводили, зважаючи на такі кількісні ознаки: трива-лість життя, міс., тривалість племінного використання, одержано опоросів (S1, σ1), одержано по-росят усього, гол. (S2, σ2), одержано живих поросят, гол. (S3, σ3), багатоплідність гол. (S4, σ4), маса гнізда на час відлучення у віці 28 діб, кг (S5, σ5), збереженість, %, тривалість міжопоросного періоду, діб, кількість непродуктивних діб з розрахунку на один опорос. Експлуатаційну цінність тварин ос-новного стада досліджували за методикою Коряжнова Е. В. (1985), рівень дискретності (D) – Се-ромолота В. В., Святченко С. И. (1984). Біометричну обробку одержаних результатів досліджень проводили за методикою Г. Ф. Лакіна (1990). Встановлено, що свиноматки великої білої породи під-контрольного стада за основними показниками відтворювальних якостей (багатоплідність, гол.; маса гнізда на час відлучення у віці 28 діб, кг) відповідають мінімальним вимогам І класу та класу еліта. Достовірну різницю між групами тварин категорій «висока експлуатаційна цінність» та «низька експлуатаційна цінність» встановлено за показниками «тривалість життя, міс.» (29,9 міс., td=13,71), «тривалість племінного використання, міс.» (29,6 міс., td=14,50), «одержано опоросів» (5,7 опоросів, td=14,50), «одержано поросят усього, гол.» (70,5 гол., td=13,85), «одержано живих поросят, гол.» (67,7 гол., td=20,83), «багатоплідність, гол.» (3,3 гол., td=10,31), «маса гнізда на час відлучення у віці 28 діб (6,5 кг, td=2,55). Коефіцієнт дискретності (D) ознак відтворювальних якос-тей свиноматок різної експлуатаційної цінності коливався в межах від 0,765 до 0,992. Максимальну прибавку додаткової продукції за показником «маса гнізда на час відлучення у віці 28 діб, кг» одер-жано від свиноматок категорії «висока експлуатаційна цінність» – 6,03 %.