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Jurors distrust eyewitness testimony when eyewitness confidence is inflated between the incident and identification in court. Nevertheless, jurors may view inflated-confidence testimony as reliable...

With populations aging rapidly across the world, an increasing amount of attention is being paid to how older eyewitnesses are perceived by jurors. Current literature reports mixed results. While s...

Our objectives in this review are 1) to define the four components of sow lifetime performance, 2) to organize the four components and other key measures in a lifetime performance tree, and 3) to compile information about sow and herd-level predictors for sow lifetime performance that can help producers or veterinarians improve their decision making. First, we defined the four components of sow lifetime performance: lifetime efficiency, sow longevity, fertility and prolificacy. We propose that lifetime efficiency should be measured as annualized piglets weaned or annualized piglets born alive which is an integrated measure for sow lifetime performance, whereas longevity should be measured as sow life days and herd-life days which are the number of days from birth to removal and the number of days from date of first-mating to removal, respectively. We also propose that fertility should be measured as lifetime non-productive days, whereas prolificacy should be measured as lifetime pigs born alive. Second, we propose two lifetime performance trees for annualized piglets weaned and annualized piglets born alive, respectively, and show inter-relationships between the four components of the lifetime performance in these trees. Third, we describe sow and herd-level predictors for high lifetime performance of sows. An example of a sow-level predictor is that gilts with lower age at first-mating are associated with higher lifetime performance in all four components. Other examples are that no re-service in parity 0 and shorter weaning-to-first-mating interval in parity 1 are associated with higher fertility, whereas more piglets born in parity 1 is associated with higher prolificacy. It appears that fertility and prolificacy are independent each other. Furthermore, sows with high prolificacy and high fertility are more likely to have high longevity and high efficiency. Also, an increased number of stillborn piglets indicates that sows have farrowing difficulty or a herd health problem. Regarding herd-level predictors, large herd size is associated with higher efficiency. Also, herd-level predictors can interact with sow level predictors for sow lifetime performance. For example, sow longevity decreases more in large herds than small-to-mid herds, whereas gilt age at first-mating increases. So, it appears that herd size alters the impact of delayed gilt age at first-mating on sow longevity. Increased knowledge of these four components of sow lifetime performance and their predictors should help producers and veterinarians maximize a sow’s potential and optimize her lifetime productivity in breeding herds.

Background Our objectives were 1) to compare reproductive performance across parities and lifetime performance of parity 1 sows in six weaning-to-first-mating interval groups (WMI 0–3, 4, 5, 6, 7–20 and 21 days or more), 2) to determine the recurrence patterns and repeatability of WMI, and 3) to quantify factors associated with the probability of parity 1 sows having WMI 4 days. Examined data comprised 691,276 parity and 144,052 lifetime records of sows in 155 Spanish herds, served between 2011 and 2016. Mixed-effects models were applied to the data. Variance components analysis determined WMI repeatability. Results Proportions of parity 1 sows with WMI 0–3, 4, 5, 6, 7–20 and 21 days or more were 4.1, 30.0, 38.4, 7.9, 12.7 and 6.9%, respectively. Of the parity 1 sows with WMI 0–4 days, 43.3–60.5% had WMI 4 days in later parities, whereas 33.9–48.9% of those with WMI ≥5 days had WMI 5 days; WMI repeatability was 0.11. Parity 1 sows with WMI 4 or 5 days had 0.3–2.1 days shorter WMI in later parities than those with WMI ≥7 days (P

Prolapses in sows are an emerging concern in pig production. The objectives of this study were to estimate the incidence rate of prolapses and to determine risk factors associated with prolapse occurrences. Data included 905,089 service records in 819,754 parity records of 155,238 sows from 144 swine herds in Spain. Producers were required to record a removal reason, including type of prolapse. A 1:4 matched case-control study was carried out to investigate prolapse risk factors, and piecewise exponential models were applied to the data. The following factors were assessed: parity, number of services, service season, weeks after service, prior gestational length, total number of piglets born, and number of stillborn and mummified piglets. Almost 1% of sows (0.8%) were removed due to prolapses (95% confidence interval: 0.76, 0.85), and the annualized incidence rate for all prolapse cases was 3.8 cases per 1000 sow-years (95% confidence interval: 3.59, 4.01). Significant factors were the 16th week after service, being in parity 3 or higher, re-service, servicing in summer, autumn or winter, shorter gestational length, fewer piglets born and more stillborn piglets (P ≤ 0.04). For example, the prolapse incidence was 30.6 times higher at 16 weeks after service than during the first 14 weeks (P

High temperature is an environmental factor that impairs sow fertility. In this study, we identified the critical weeks for heat stress effects on aspects of fertility performance, namely weaning-to-first-service interval (WSI) and farrowing rate (FR). We also examined the threshold temperatures above which the fertility performance deteriorated and whether there were any differences between parities regarding heat stress effects or thresholds. Performance data of sows in 142 herds from 2011 to 2016 were matched to appropriate weekly averaged daily maximum temperatures (Tmax) from weather stations close to the herds. Two types of ratios (i.e., ratio for WSI and odds ratio for FR) were used to identify the critical weeks for heat stress by comparing the respective measures for two sow groups based on Tmax in different weeks around weaning or service events. The ratios for WSI were calculated between groups of sows exposed to Tmax ≥ 27 °C or

Female pigs in breeding herds can be managed through four phases-gilt development, breeding, gestation, and lactation-during which they may be housed in group or individual pens, stalls, or on pasture. In this review, we focus on housing environments that optimize outcomes during gestation and lactation. Appropriate housing is important during early gestation, to protect embryos and to confirm pregnancy, and from mid-to-late gestation, to ensure sufficient nutrition to increase placental and fetal growth. No difference in the number of pigs born alive were reported between group housing and individual stall housing, although more risk factors for reproductive performance are associated with group housing than stall housing including genetics, bedding, floor space allowance, group size, social ranking, and parity. Furthermore, lameness in pregnant pigs is more frequent in group housing than in stall housing. Housing during lactation helps protect piglets from being crushed or from contracting disease, and can foster the transfer of enough colostrum from mother to piglets. Indeed, lactating sows in pen housing tend to have higher pre-weaning mortality and lighter litter weights than those in crated housing.

High temperature is one of the environmental factors which impair sow fertility such as weaning-to-first-mating interval (WMI) and farrowing rate especially in parity 1 sows. The objective of this study was to explore thresholds of temperature damaging fertility in different parity sows. Data of sows serviced from 2011 to 2016 in 142 herds were coordinated with daily maximum temperature (Tmax) from 31 weather stations close to the herds. A two-stage approach was used to determine the best fit model. In the first stage, means and their variance-covariance matrix in each degree Celsius were estimated by a mixed model. Then, piecewise models with a different breakpoint were fitted to the estimates by generalized least squares. Medians of WMI in parity 1 and 2 or higher sows were 5 and 4 days, respectively. Farrowing rates in different parity sows were 85.0–88.7%. The thresholds of mean Tmax during lactation leading to a prolonged WMI were 16 and 23–25°C for parity 1 and 2 higher sows, respectively. The 10°C increase in Tmax from the thresholds delayed WMI in parity 1 and 2 or higher sows by 0.62 and 0.46–0.49 days, respectively (P < 0.01). Meanwhile, the thresholds of mean Tmax from 21 to 14 days before service leading to reductions in farrowing rate were 21, 19 and 21–22°C for parity 0, 1 and 2 or higher sows, respectively. As the Tmax increased by 10°C from the thresholds, farrowing rate in parity 0–1 and 2 or higher sows decreased by 2.9 and 2.2–2.6%, respectively (P < 0.01). Lactating sows in parity 1 suffered from heat stress at a relatively low outdoor temperature. This implies that the temperature is warmer in lactating barns than in outdoor. We recommend changing thermostat set at barns in spring from those in winter in order to increase ventilation rates earlier.

Abortion occurrences disturb the projected production volume and increase non-productive days of female pigs. The objectives of the present study were (1) to define abortion occurrences including abortion rate and abortion risk, (2) to examine risk factors that were associated with abortions, (3) to determine repeatability of abortions and (4) to compare reproductive performance between aborting and non-aborting re-serviced female pigs. Datasets included 122,935 lifetime performance records and 630,363 mating performance records of females in 125 herds between 2008 and 2013 in Spain, Portugal and Italy. Annualized abortion rate was defined as the number of abortion records divided by the sum of the reproductive herd life days×365 days×100. Abortion risk per service was defined as the number of abortion records divided by the number of service records×100. Generalized linear models with random herd effect were applied to the data. Annualized abortion rate (±SE) and abortion risk per service were 3.0±0.05 and 1.2±0.01%, respectively. Factors for an increased abortion risk per service were parity 0 or parity 5 or higher, re-servicing, servicing in July and August, delivering stillborn fetuses in a previous litter and having prolonged weaning-to-first-mating interval (WMI; P

We demonstrated GaN-based vertical-cavity surface emitting lasers (VCSELs) with 5–30 μm wide nano-height cylindrical waveguide formed by BCl3 etching. A 5 nm-depth etching with BCl3 showed the most efficient current blocking at the interface of the etched p++-GaN and an ITO electrode among the cases with BCl3, Ar, or O2, which could be due to not only etching damages but also diffused B atoms into the etched surface. While room-temperature continuous-wave operations of the VCSELs with the large apertures were demonstrated, maximum light output power values of the large aperture VCSELs seemed limited by nonuniform current injection and device thermal resistances.

Lameness is a major reason for sow removal in breeding herds. Increased removal occurrences for lameness decrease reproductive efficiency and increase welfare concerns. Therefore, the objectives of this study were to estimate the incidence rate of removal due to lameness, and to investigate the longevity and reproductive performance of sows removed due to lameness. Poisson regression models were applied to a cohort dataset of 137,907 sows in 134 herds located in Spain. The Wilcoxon rank sum test was used to compare the performance of sows removed due to lameness and their controls in one-to-two matched case-control datasets. Removal due to lameness accounted for 4.3 % of all removed sows, and the incidence rate was 19.6 cases per 1000 sow-years (95 % confidence interval: 15.03, 25.51). The majority (70.4 %) of those removed were farrowed sows, whereas only 29.6 % were serviced sows. In farrowed sows, a higher incidence of removal due to lameness was associated with weeks 4-9 after farrowing, higher parity and winter farrowing (P 0.01). The removal incidence was 24.7-33.1 times higher in weeks 4-9 after farrowing than during the first week after farrowing (P 0.01). It was 1.3-1.6 times higher in parity 4-5 than in parity 1, and 1.3 times higher for winter farrowing than for summer farrowing (P 0.01). In contrast, the factors associated with removal due to lameness with serviced sows were weeks 4-5 after service and being re-serviced (P 0.01). The service sow removal incidence was 4.7 times higher in weeks 4-5 after servicing than during the first 2 weeks after servicing (P 0.01). Also, it was 2.2 times higher in re-serviced sows than in first serviced sows (P 0.01). However, removal in serviced sows was not associated with parity (P = 0.10) or service season (P = 0.39). In the case-control datasets, the sows removed due to lameness had higher weaning-to-first-mating interval (means: 6.5 vs. 5.8 days), fewer piglets born alive (11.7 vs. 12.5 piglets) and lower parity at removal (3.4 vs. 4.9; P 0.01) than sows removed for other reasons or non-removed sows. However, there was no difference in gilt age at first service between the case and control groups (P = 0.29). We recommend identifying sows showing early signs of lameness and treating them with pain medication until removal. The best time for removal would be at weaning when non-productive sow days start.

We aimed to further improve performances of GaN-based vertical cavity surface emitting lasers (VCSELs) by applying a combination of conducting distributed Bragg reflectors (DBRs) and lateral optical confinement structures simultaneously, generally used in GaAs-based VCSELs. Si-doped conducting AlInN/GaN DBRs and buried SiO2 apertures were adopted in the GaN-based VCSELs. By comparing the VCSELs and micro LEDs to those with undoped non-conducting DBRs, we found that lower device resistances and more uniform lateral current distributions were obtained with the conducting DBRs. At the same time, the maximum light output power of 2.6 mW was observed from the VCSEL with the conducting DBR while 4.4 mW was obtained from the VCSEL with undoped DBR. Inferior characteristics of a GaInN quantum well active region was found on the Si-doped conducting DBR.

Objectives were to determine climatic and production factors associated with abortions in commercial swine herds and to compare the reproductive performances and culling patterns between aborting and non-aborting females that were re-inseminated. There were 309,427 service records analyzed for 56,375 females entered into 100 herds. Climate data were obtained from 21 weather stations located close to the herds. Mean daily average temperatures (Tavg) for the 21-day pre-mating period for each female were combined with the female's reproductive data. Generalized linear model assessments were conducted for abortion risk per service. Abortion risk per service (±SE) was 0.7±0.06%, and mean value of Tavg (range) was 15.0 °C (-10.7 to 32.7 °C). Risk factors associated with an increased abortion risk per service were greater numbers of parities, delivering more stillbirth fetuses, greater mean Tavg for the 21-day pre-mating periods and re-servicing of females that did not get pregnant at the first servicing (P0.05). Abortion risk per service for parities 1-5 increased by 0.1-0.3% when the Tavg increased from 20 to 30 °C (P0.05), but there were no such associations for parities 0 and 6 or greater (P≥0.37). Aborting re-serviced females had 0.4 fewer pigs born alive than non-aborting re-serviced females (P0.05). Also, 64.6% of all aborting females were culled for reproductive failure, compared with only 23.4% of non-aborting females. In conclusion, producers should closely monitor females at greater risk of aborting and apply more advanced cooling systems.

Our objectives were 1) to compare reproductive performance across parity and lifetime performance in sow groups categorized by the number of pigs born alive (PBA) in parity 1 and 2) to examine the factors associated with more PBA in parity 1. We analyzed 476,816 parity records and 109,373 lifetime records of sows entered into 125 herds from 2008 to 2010. Sows were categorized into 4 groups based on the 10th, 50th, and 90th percentiles of PBA in parity 1 as follows: 7 pigs or fewer, 8 to 11 pigs, 12 to 14 pigs, and 15 pigs or more. Generalized linear models were applied to the data. For reproductive performance across parity, sows that had 15 or more PBA in parity 1 had 0.5 to 1.8 more PBA in any subsequent parity than the other 3 PBA groups ( P< 0.05). In addition, they had 2.8 to 5.4% higher farrowing rates in parities 1 through 3 than sows that had 7 or fewer PBA (P < 0.05). However, there were no differences between the sow PBA groups for weaning-to-first-mating interval in any parity (P ≥ 0.37). For lifetime performance, sows that had 15 or more PBA in parity 1 had 4.4 to 26.1 more lifetime PBA than sows that had 14 or fewer PBA (P < 0.05). Also, for sows that had 14 or fewer PBA in parity 1, those that were first mated at 229 d old (25th percentile) or earlier had 2.9 to 3.3 more lifetime PBA than those first mated at 278 d old (75th percentile) or later (P < 0.05). Factors associated with fewer PBA in parity 1 were summer mating and lower age of gilts at first mating (AFM; P < 0.05) but not reservice occurrences (P = 0.34). Additionally, there was a 2-way interaction between mated month groups and AFM for PBA in parity 1 (P < 0.05); PBA in parity 1 sows mated from July to December increased nonlinearly by 0.3 to 0.4 pigs when AFM increased from 200 to 310 d old (P < 0.05). However, the same rise in AFM had no significant effect on the PBA of sows mated between January and June (P ≥ 0.17). In conclusion, high PBA in parity 1 can be used to predict that a sow will have high reproductive performance and lifetime performance. Also, the data indicate that the upper limit of AFM for mating between July and December should be 278 d old.

We review critical factors associated with reproductive performance of female breeding pigs, their lifetime performance and herd productivity in commercial herds. The factors include both sow-level and herd-level factors. High risk sow-level groups for decreasing reproductive performance of female pigs are low or high parity, increased outdoor temperature, decreased lactation feed intake, single inseminations, increased lactation length, prolonged weaning-to-first-mating interval, low birth weight or low preweaning growth rate, a few pigs born alive at parity 1, an increased number of stillborn piglets, foster-in or nurse sow practices and low or high age at first-mating. Also, returned female pigs are at risk having a recurrence of returning to estrus, and female pigs around farrowing are more at risk of dying. Herd-level risk groups include female pigs being fed in low efficiency breeding herds, late insemination timing, high within-herd variability in pig flow, limited numbers of farrowing spaces and fluctuating age structure. To maximize the reproductive potential of female pigs, producers are recommended to closely monitor females in these high-risk groups and improve herd management. Additionally, herd management and performance measurements in high-performing herds should be targeted.

Thermal reactions of empty fullerenes with disilirane (1) and digermirane (2) afforded the corresponding bis-silylated and bis-germylated derivatives. When a bicyclic fused silirane (3a) was heated in the presence of C70, two silylene adducts were obtained through thermal extrusion of silylenes. These results provide a complementary method to the photochemical addition of reactive silicon and germanium compounds, which have been long employed for derivatization of fullerenes. Electrochemical analyses revealed the redox properties of the silylated and germylated C70, indicating the electronic perturbation caused by silyl and germyl groups introduced on the fullerene cages. Theoretical calculations were also conducted for understanding of the electronic property of the fullerene derivatives.

The objective of this study was to examine interactions between climatic factors, parity, and weaning-to-first-mating interval (WMI) for total number of pigs born at subsequent parity (TPB) of female pigs serviced during 2 seasons. The present study analyzed records of 27,739 gilts and 127,670 parity records of sows in 95 Japanese herds; the records included females that were serviced between June and September (hot and humid season) or between December and March (cold season) in 2007 through 2009. The climate data were obtained from 20 weather stations located close to the studied herds. Mean daily maximum temperatures (Tmax), mean daily minimum temperatures (Tmin), and daily average relative humidity (RH) for 21 d preservice and 15 d postservice for each female were coordinated with that female's reproductive data. Linear regression models with random intercept and slopes were applied to the data. Mean TPB (±SEM) was 11.9 ± 0.01 pigs. Mean values (ranges) of Tmax in the hot and humid season and Tmin in the cold season were 28.4 (13.6 to 39.8°C) and 2.0°C (-13.2 to 17.6°C), respectively. Also, mean RH in the hot and humid season and the cold season were 73.2 (35 to 98%) and 65.2% (25 to 99%), respectively. In the hot and humid season, TPB in gilts decreased by 0.05 pigs for each degree Celsius increase in preservice Tmax (P < 0.05). However, there was no association between gilt TPB and either postservice Tmax (P = 0.11) or pre- and postservice RH (P ≥ 0.66). In sows, as preservice Tmax increased from 25 to 30°C, TPB in parity groups 1 and 2 or higher decreased by 0.6 and 0.4 pigs, respectively (P < 0.05). Also, sow TPB decreased by 0.1 to 0.4 pigs as postservice Tmax increased from 25 to 30°C (P < 0.05). In sows with WMI of 0 to 12 d, TPB decreased by 0.2 to 0.5 pigs as pre- or postservice Tmax increased from 25 to 30°C (P < 0.05). However, in sows with WMI of 13 d or more, TPB was not associated with pre- or postservice Tmax (P ≥ 0.10). As preservice Tmax increased from 25 to 30°C, TPB in sows under 81.6% RH (90th percentile) decreased by 0.5 pigs (P < 0.05), whereas TPB in sows under 65.7% RH (10th percentile) decreased by only 0.3 pigs (P < 0.05). Postservice RH in the hot and humid season was not associated with sow TPB (P = 0.18). During the cold season there was no association between TPB and pre- or postservice Tmin (P ≥ 0.09) or RH (P ≥ 0.45). Therefore, we recommend that producers apply cooling management for females during periservice in summer to increase TPB.

Thermal reactions of C60 with siliranes (1a, b) afforded carbosilylated C60 derivatives. When a bicyclic fused silirane (1c) was employed instead of 1a and 1b, a silylene adduct and its hydrolyzed compound were obtained through thermal extrusion of silylenes from 1c. These products were determined to be 1,2-adducts at 6,6-junctions of C60 by MS, UV, and NMR analyses. These results provide a complementary method to the photochemical addition of reactive silicon compounds, which have been long employed for silylation of C60. Electrochemical analyses revealed the redox properties of the silylated products, indicating the perturbation caused by silyl groups introduced on the C60 cage. Theoretical calculations were also conducted for understanding of the electronic property of the silylated product.

Our objective was to characterize use of nurse sows in Spanish breeding herds. We analyzed 466 111 parity records and lifetime records of 92 716 sows farrowed between 2011 and 2017 in 69 herds having nurse records. Nurse sows were defined as sows that had weaned 2 or 3 litters in the same lactation period. Mixed-effects models were applied to the data to compare reproductive performance and lifetime productivity between nurse and non-nurse sows. Of all the sows, 6 705 (7.2%) sows served as nurse sows at least once in their lifetime, with 10.2% of the nurse sows having a second nurse event in a later parity. Mean values (SE) of lactation length and number of piglets weaned were 31.0 (0.11) days and 21.9 (0.04) piglets in nurse sows, respectively. Across parities 2-6, nurse sows had 1.9-3.0% greater proportions of weaning-to-first-mating interval 7-20 days than non-nurse sows (P < 0.05). There was no difference between nurse sows and non-nurse sows in farrowing rate in any parity (P ≥ 0.13) and piglets born alive in parities 1-5 (P ≥ 0.15). Also, nurse sows had 3.7-7.4 more annualized lifetime piglets weaned than non-nurse sows (P < 0.01), because nurse sows had similar lifetime non-productive days with non-nurse sows (P ≥ 0.07), but produced 9.3-12.0 more lifetime piglets weaned than non-nurse sows (P < 0.01). Using nurse sows could be a good practice to cope with highly prolific sows.

We investigated and improved optical waveguides along the vertical and horizontal directions in 450 nm GaInN laser diodes. As a result, we demonstrated a low threshold current density (1.15 kA cm−2) of a GaInN ridge stripe laser diode containing a 3-pair 40 nm Al0.82In0.18N/25 nm Al0.03Ga0.97N multiple bottom cladding layer at room temperature under pulsed condition. This threshold current density is smaller than our typical value with a 1 μm Al0.03Ga0.97N bottom cladding layer. AlInN/AlGaN multiple layers are useful as n-type cladding layers in visible laser diodes to achieve higher optical confinement factors while smooth surfaces were obtained.

The objective of the present study was to quantify the associations between age at first mating (AFM) in gilts and the climatic factors of photoperiod (PP; h), number of hot days (HD) and relative humidity for different herd productivity groups. This study used records of 37,362 gilts born in 2007 and 2008 in 101 Japanese herds, which were classified into high-performing and ordinary herds based on the pigs weaned per mated female per year. The climate data were obtained from 21 weather stations. The HD was defined as the number of days that achieved a maximum temperature25°C. Average values of daily PP, relative humidity and HD from day 91 to 150 after birth of a gilt were coordinated with the respective gilt performance data. Two-level mixed-effects models were applied to the data by using a herd at level 2 and a gilt at level 1. Mean AFM (ranges), PP, HD and relative humidity were 247.9 days old (152-364 days old), 12.2h (9-15h), 18.7 days (0-60 days) and 68.4% (48-87%), respectively. Delayed AFM was associated with decreased PP, more HD and being in an ordinary herd (P0.05), but not with relative humidity. As PP rose by an hour, the AFM in high-performing herds decreased by 1.13 days rather than that in ordinary herds. It is possible that AFM in replacement gilts could be hastened by improving light control and cooling management during hot days.

The objective of the present study was to quantify the associations between climate data and either weaning-to-first-mating interval (WMI) or adjusted 21-day litter weights of sows during summer for different herd productivity groups. This study was conducted using 87,428 parity records of 61,558 sows farrowed between June and September in 2007, 2008 and 2009, in 103 Japanese herds mostly located in humid subtropical areas. The 103 herds were classified into high-performing herds and ordinary herds by the basis of the upper 25th percentile of pigs weaned per mated female per year, averaged over the three years. The climate data were obtained from 21 weather stations of the Japan Meteorological Agency. Average values of the daily maximum temperatures (HT), average daily relative humidity (RH) and temperature-humidity index (THI) for 21 days after the farrowing date of a sow were coordinated with sow performance data from a recording system. Two-level mixed-effects models were applied to the data by using a herd at level 2 and an individual record at level 1. Mean values (ranges) of HT, RH and THI were 27.8 °C (17.3–36.0 °C), 74.6% (57.3–90.9%) and 22.2 °C (13.0–27.4 °C), respectively. Higher HT, RH and THI were associated with higher WMI and lighter adjusted 21-day litter weights (P

The objective of the present study was to compare management procedures and production factors between low-farrowing-rate herds (LFR herds) and the remaining herds (Non-LFR herds). The questionnaires were sent to the producers of 115 herds that use the same recording system. The questionnaire requested information about management procedures in 2008: (i) daily frequencies of estrus detection: once or twice a day; and (ii) the timing of first insemination. Data from 93 completed questionnaires (80.9%) were coordinated with the reproductive data of individual female pigs from the recording system. The data included 78,321 service records from 37,777 sows and gilts. Herds were classified into two groups on the basis of the lower 25th percentile of farrowing rate: LFR herds (76.5% or lower) and Non-LFR herds (76.6% or higher). At the herd level, a two-sample t-test, was used to compare the surveyed management procedures between the two herd groups. At the individual level, two-level mixed-effects models were applied, by using a herd at the level two and an individual record at the level one to determine associations between low farrowing rate and management procedures or production factors in gilts and sows. Gilt and sow models were separately constructed. Means (±SEM) of farrowing rate in LFR herds and Non-LFR herds were 71.3±0.92 and 85.5±0.54%, respectively. The lower farrowing rates of gilts and sows in LFR herds were associated with once-daily estrus detection, late timing of first insemination and single mating (P0.05). In LFR herds that detected estrus only once a day, the farrowing rate decreased by 10.5% in first-serviced gilts and by 4.2% in reserviced sows compared with twice daily estrus detection (P0.05). However, there was no such association in Non-LFR herds (P0.05). The LFR herds had higher percentages of single-mated gilts and sows than Non-LFR herds (P0.05). Fewer LFR herds than Non-LFR herds performed first insemination immediately after first estrus detection for gilts or by 6-12h for sows (P0.05). In order to improve the farrowing rate in LFR herds, we recommend detecting estrus twice a day and performing first insemination earlier after first estrus detection; immediately for gilts and by 6-12h for sows. Additionally, increasing the percentage of multiple inseminations can effectively improve the farrowing rate.

Reproductive performance, lifetime performance and removal hazard were studied in commercial herds in order to detect prolific sows at an early-stage. Reproductive performance measurements that we assessed were number of pigs born alive (PBA) per litter, weaning-to-first-mating interval and farrowing rate (FR). Lifetime performance measurements included lifetime average PBA and lifetime average nonproductive days. In total, 213,514 parity records and 47,024 lifetime records of 96 herds were included. Sows were categorized into three groups based on the lower and upper 25th percentiles of PBA in parity 1:8 pigs or fewer, 9-12 pigs and 13 pigs or more. The herds were classified into high- and low-performing herds on the basis of the 50th percentile of pigs weaned per mated female per year. To compare the measurements between the sow groups taking account for the herd productivity groups, multivariate and single response models were applied to reproductive performance from first-farrowing and lifetime performance, respectively. A hazard model was fitted to survival data. Sows having 13 or more PBA in parity 1 had 1.0-1.4 more PBA per litter in all subsequent parities (P0.05), 1.2-1.5% higher FR in parities 2-4 (P0.05) and 3.4-3.7 higher lifetime average PBA than sows having 8 or lower PBA (P0.01). However, there were no differences between the sow groups for weaning-to-first-mating interval in any parity (P0.05). There were two-way interactions between the sow and herd groups for FR in parity 2 (P=0.01) and lifetime average nonproductive days (P=0.046). In low-performing herds, sows having 13 or more PBA in parity 1 had 3.9% higher FR at their next farrowings than sows having 8 or fewer PBA (P0.05), although no such difference was found for high-performing herds (P0.05). Sows in the low-performing herds with 13 or more PBA in parity 1 also had 2.3 fewer lifetime average nonproductive days than sows having 8 or fewer PBA (P=0.01), although again no similar difference was found for high-performing herds (P=0.96). The removal hazards for sows having 13 or more PBA in parity 1 were lower than those for sows having 8 or fewer PBA (P0.01), with no difference in hazards between the herd groups (P=0.62). In conclusion, PBA in parity 1 may help predict a prolific sow or low PBA sow.

Our objective was to characterize eating behavior associated with displacement hazard and subsequent performance for pigs were fed in static groups by an electronic sow feeder (ESF). Data included weekly eating records and subsequent farrowing records of 685 pigs. The eating behavior comprised weekly averages of daily feed dispensed (ADFD) and daily total time spent in the feeding stations (TTSF). A displacement female was defined as a pig removed from her group for health reasons. A multivariate model and piecewise exponential models were fitted to the records. Means (inter-quartile ranges) of ADFD and TTSF were 2.4 kg (2.1-2.8 kg) and 9.3 min (7.5-10.8 min), respectively. Gilts had less ADFD than sows during gestational weeks 5-13 (P < 0.05), but there was no difference in TTSF between gilts and sows in gestational weeks 5-8 and 11-13 (P > 0.05). Also, gilts had higher displacement hazard than parity 2 or higher sows in gestational weeks 8-10 (P < 0.05). Pigs that were entered into the ESF system during summer had less ADFD, and shorter TTSF from gestational weeks 5 to 12 than those entered during the other seasons (P < 0.05). The TTSF varied between two genotypes during gestational weeks 5-7 (P < 0.05). Also, a higher displacement hazard was associated with less ADFD (P < 0.01). A higher hazard of pregnancy loss was associated with shorter TTSF (P < 0.01). In conclusion, we recommend that both ADFD and TTSF should be measured in ESF systems to help identity females having problems.

Our objective was to quantify the associations between climatic factors and a death occurrence of peripartum pigs from 16 to 19 weeks after successful service during hot and humid or cold seasons. The study used lifetime records of 93,837 females entered into 98 Japanese commercial herds from 2003 to 2007. The climate data were obtained from 21 weather stations close to the studied herds. Average daily maximum (HT) and minimum temperature (LT), and relative humidity for week 15 of gestation for each pregnant pig were coordinated with the respective pig's performance data. Multilevel logistic regression models were applied to two of the three separate datasets. One dataset included females due to farrow during the hot and humid season (June-September), and another comprised females due to farrow during the cold season (December-March). Of the 8381 females that died throughout the year, 11.5% of pregnant pigs died between 16 and 17 weeks after service, and 44.3% of farrowed females subsequently died from 16 to 19 weeks after service. Mean (ranges) HT in the hot and humid season and LT in the cold season were 28.7 (13.4-39.8) °C and 1.6 (-14.8 to 17.6) °C, respectively. Means of relative humidity in the hot and humid season and cold season were 73.6 (35-98)% and 64.9 (21-99)%, respectively. In the hot and humid season, a higher HT was associated with a higher occurrence of death for parity 0-1 females (P

The objectives of this study were to determine the associations between climatic factors and production factors for returns to service of female pigs during summer and to quantify the associations between these factors and occurrences of returns to service. The factors that were assessed were as follows: maximum temperature (HT), relative humidity, age of gilts at first mating, parity, weaning-to-first-mating interval (WMI), and lactation length. The study analyzed records of 18,307 gilts in 99 herds and 78,135 parity records of 56,322 sows in 103 herds; all the females were first-serviced between June and September, 2007 to 2009. Average daily HT and relative humidity for 15 days post-service of a female were obtained from 21 local weather stations and coordinated with the performance data of the respective local herds. The returns to service were categorized into three groups: regular returns (RRs: 18-24 days), irregular returns (IRs: 25-38 days), and late returns to service (LRs: 39 days or later). Two-level mixed-effects models were applied to the data by using a herd at level 2 and an individual record at level 1. In mated gilts, the occurrences (%) of RRs, IRs, and LRs were 4.8%, 1.8%, and 5.3%, respectively. In mated sows, the respective occurrences were 3.3%, 1.8%, and 4.2%. Mean values (ranges) of HT and relative humidity were 28.4 °C (13.6 °C-39.8 °C) and 73.4% (35.0%-98.0%), respectively. In gilts, as HT increased from 25 °C to 30 °C, the occurrence of RR increased from 3.7% to 4.4% (P0.05). However, there was no association between the occurrence of RR and either relative humidity (P = 0.17) or age at first mating (P = 0.23). In addition, there were no associations between the occurrences of either gilt IR or LR and HT (P ≥ 0.05), relative humidity (P ≥ 0.46), or age at first mating (P ≥ 0.32). In sows, greater occurrences of RRs, IRs, and LRs were associated with higher HT, lower parity, and a WMI of 7 days or longer (P0.05), but they were not associated with relative humidity (P ≥ 0.62) or lactation length (P ≥ 0.13). The occurrence of RRs in sows of all WMI groups increased 1.22 (1.04(5)) times for each 5 °C increase in HT. For sows with WMI 0 to 6 days, each 5 °C rise in HT increased the occurrence of IRs and LRs by 1.36 (1.06(5)) and 1.27 (1.05(5)) times, respectively. However, there was no association between increased HT and occurrences of IRs or LRs for sows with WMI 7 days or longer (P ≥ 0.38). Therefore, in order to prevent returns to service, it is recommended that producers apply cooling management for females during the post-service periods in summer.

Our objective was to examine interactions between climatic factors and either parity or total number of pigs born for the occurrence of sows having stillborn piglets (SBP) and on the number of SBP, during two seasons.