Creep Area Research Articles

Sows and piglets adjust their use of an outdoor paddock with season and piglet age during the first weeks of life in an organic farm

Few studies have examined sows and piglets' use of outdoor access during their first weeks of life, when reared with access to a hut and a pasture as in the organic system. We studied whether the age of the piglets and the season of the year influenced the use of an outdoor area by piglets and the sow, and the use of indoor spaces. For this, the localisation of sows and their piglets inside and outside the hut was analysed on 16 sows and their litters during the summer and 16 others during the winter, by scan sampling, on days 2, 7 and 13 after parturition in an organic herd in Denmark. When inside the hut, the number of piglets in the creep area, next to the sow or other piglets was noted. All parameters were analysed by linear mixed-effects ANOVA models. Sows were less often observed outside the hut in the wintertime and during the mornings compared to later times of the day (P<0.001). Furthermore, the sows increased their outdoor use with the age of their litter (P<0.001). The season also influenced the piglet use of outdoor areas (winter < summer; P<0.001). Piglets that were observed outside for the first time were older (8.9±0.9 d) during winter than during summer (3.5±0.5 d). The proportion of piglets observed outside increased with age, with a significant Season x Age interaction (P<0.001). The proportion of observations where the sows and piglets were outdoors together increased with the piglets’ age (P < 0.001). Sows’ outing was correlated with summer (R=0.3) and winter (R=0.2) temperatures, unlike piglets, where outings were correlated only with summer temperatures (R=0.3, P<0.001). The proportion of piglets observed in the creep area was significantly affected by the age with a Season x Age interaction effect (P<0.001). Piglets were rarely observed lying alone inside the hut. The proportion of piglets in contact with the sow and other piglets inside the pen was influenced by a significant Age x Season interaction effect (P<0.001). We showed that piglets given access to an outside paddock gradually increase their use with age and don’t go outside right away. Their first exit and the proportion of piglets outside depended also on the season. In general, a higher proportion of sows and piglets were observed indoor during the wintertime. Thus, sows and piglets adjust their use of outdoor paddock with season and piglet age during the first weeks of life.

Behavioural characteristics of fatal piglet crushing events under outdoor conditions

Piglets being crushed by the sow is a major welfare challenge in outdoor pig production. To develop interventions with the highest impact on mitigating crushing, it is necessary to know whether the major behaviour leading up to crushing can be considered mainly sow- or piglet-related or due to inappropriate housing conditions and thus whether the genetics of the sow is a factor of importance. In this observational study, piglets classified as fatally crushed based on necropsy were identified on video recordings. Seventy-two crushing events were observed on video in 32 litters. Forty of the events took place in 17 litters born by DanBred Landrace × Yorkshire hybrid sows while 32 events took place in 15 litters born by Topigs Norsvin TN70 hybrids (TN70). The fatal posture changes were rolling (31%), standing to sternal lying (22%), standing to lateral lying (11%, where half were classified as ‘flopping’), sitting to sternal lying (11%), stepping on a piglet (11%), minor movement (10%), sternal lying to standing (3%) and lateral lying to standing (1%). We hypothesised that a larger proportion of the fatal crushing events could be attributed to either inadequate maternal behaviour (no exploration of piglet location before lying down, ‘flopping’ or not responsive to squeezing a piglet), inappropriate housing (squeezing against inventory), low piglet vitality (weak/damaged before) or an unattractive creep area (piglets clustering near the sow). There were no detectable differences between parity and hybrid on whether the sow explored before or made a posture change after crushing. One-third of the crushed pigs were weak/damaged before and took up a larger proportion of the fatally crushed piglets in DanBred (38%) vs. TN70 (16%) sows. ‘Flopping’ and squeezing against inventory were rare (7% and 1%, respectively). The sow explored before lying down in 42% of the events. Exploring before occurred more often before lying sternal and before stepping on a piglet than for all other fatal sow posture changes (P < 0.01). In 18% of the fatal events, the sow made a new posture change within one minute. Based on the findings, options to reduce crushing are discussed, including genetic selection for maternal behaviour and more robust piglets, housing conditions to slow sow posture changes and/or by attracting piglets away from the danger zone.

Farrowing Pens for Individually Loose-Housed Sows: Results on the Development of the SowComfort Farrowing Pen

The objective of the present paper was to discuss the design of farrowing pens and present the first production results of the “SowComfort farrowing pen” (SOWCOMF). The biggest difference between this pen and the traditional pen (TRAD) presented in the study, is that SOWCOMF contains a nest area equipped with a rubber mattress, floor heating, a rack for straw and no separate creep area. It was predicted that SOWCOMF would result in lower piglet mortality compared to TRAD due to a more stimulating and comfortable environment, and that the use of rubber mats in SOWCOMF would reduce the incidence of carpal joint lesions of the piglets. Results from both farms showed that percent mortality of live born piglets was lower in SOWCOMF than TRAD (p = 0.004), especially due to starvation (p &lt; 0.0001) and other causes (p &lt; 0.0001). In contrast, percentage of overlying was higher in SOWCOMF (p &lt; 0.0001). The lower incidence of starved piglets in SOWCOMF than TRAD can possibly be explained by more sow-initiated communication with the piglets (p &lt; 0.001). Most causes of mortality declined over consecutive batches. Percentage of piglets per litter without carpal lesions were significantly higher in the SOWCOMF than in TRAD (p &lt; 0.0001), showing that rubber mats provide more protection of carpal joints.

Impact of housing environment and management on pre-/post-weaning piglet productivity.

The complex environment surrounding young pigs reared in intensive housing systems directly influences their productivity and livelihood. Much of the seminal literature utilized housing and husbandry practices that have since drastically evolved through advances in genetic potential, nutrition, health, and technology. This review focuses on the environmental interaction and responses of pigs during the first 8 wk of life, separated into pre-weaning (creep areas) and post-weaning (nursery or wean-finish) phases. Further, a perspective on instrumentation and precision technologies for animal-based (physiological and behavioral) and environmental measures documents current approaches and future possibilities. A warm microclimate for piglets during the early days of life, especially the first 12 h, is critical. While caretaker interventions can mitigate the extent of hypothermia, low birth weight remains a dominant risk factor for mortality. Post-weaning, the thermoregulation capabilities have improved, but subsequent transportation, nutritional, and social stressors enhance the requisite need for a warm, low draft environment with the proper flooring. A better understanding of the individual environmental factors that affect young pigs as well as the creation of comprehensive environment indices or improved, non-contact sensing technology is needed to better evaluate and manage piglet environments. Such enhanced understanding and evaluation of pig–environment interaction could lead to innovative environmental control and husbandry interventions to foster healthy and productive pigs.

Light from heat lamps affects sow behaviour and piglet salivary melatonin levels

The light environment regulates animal physiology and behaviour. As widely used supplementary heat sources in creep areas, the effect of visible light radiated by infrared heat lamps on pigs is worth investigating. To investigate the effects of light from heat lamps on the behaviour of sows and piglets and possible endocrine mechanisms, 24 primiparous sows were randomly assigned to three supplementary heat source treatments: (1) 250 W non-luminous ceramic heat lamps (CE, n = 8), (2) 175 W red heat lamps (RL, n = 8), and (3) 175 W transparent heat lamps (TL, n = 8). All heat lamps were turned off on Day 15 postpartum. Piglets were weighed on days 3 and 21 postpartum. The number and duration of suckling within 24 h were analysed via video recordings on days 4, 8, and 16 postpartum. Sow posture changes during the day and night were detected using the YOLOv4 target detection network model. One marked piglet from six litters randomly selected from each treatment was used for saliva collection. Saliva samples were collected at 0800, 1400, 2000, and 0200 (+1 d) on days 10 and 20 postpartum. The results showed that the mean postural change frequency of TL sows was higher than that of CE sows (P < 0.05), while that of RL sows was not different from that of CE and TL sows. However, the duration of the sows being in each posture was not affected by the treatment. The total suckling duration of TL piglets was significantly longer than that of CE piglets, but there was no significant difference in the performance of the piglets. The melatonin concentrations in the saliva of piglets at 10 and 20 days of age in the three treatments showed different diurnal rhythms, but there was no significant difference in the levels of melatonin in TL piglets between night and day. Differences in salivary cortisol levels only appeared between the CE and RL groups at 20 days of age. Based on the present results, the illuminance and spectrum of the transparent heat lamps were sufficient to stimulate sow activity and inhibit melatonin levels in piglets. However, the stimulating effect on suckling was not sufficient to significantly improve the performance of piglets. Exposure to red heat lamps, rather than ceramic lamps, resulted in the strongest circadian rhythm of salivary melatonin in piglets.

Postpartum dysgalactia syndrome in sows: effects on behavior of sows and piglets

BackgroundTo investigate if specific sow and piglet behavioral characteristics could be used diagnostically, this case-cohort study of the behavior of sows and piglets during the periparturient period (from 24 h before the birth of first piglet to 24 h after the birth of last piglet) was conducted. Data included 32 sows diagnosed with PDS (PDS+) vs. 37 healthy matched controls (PDS−) and their litters.ResultsA significant change from active behavior with many postural changes to a more passive behavior was noted in connection with parturition. Sow nesting behavior was less frequent in PDS+ sows compared to PDS− sows during (p = 0.04) and after parturition (p = 0.0004). No difference was found between PDS+ and PDS− in the number of postural changes, interval from last time standing to the birth of the first piglet, interval from last time eating/drinking to the birth of the first piglet, interval from the birth of the first piglet to the sow standing after farrowing, interval from the birth of the last piglet until eating/drinking, occurrence of bar biting, or frequency or duration of eating/drinking during the observation period. Piglets of PDS+ sows stayed outside the creep areas more often than piglets of PDS− sows (p < 0.0001), but there was no difference in the mean number of piglets observed massaging the udder every 10 min.ConclusionThese results confirm that sow behavior changes from active before parturition to more passive after parturition. Being diagnosed with PDS affected the periparturient behavior of sows as well as their piglets. The observed reduction in nesting behavior in PDS+ sows may suggest that a highly motivated piglet-oriented behavior was affected. However, classical sickness behaviors like lethargy and passivity seem to be poor markers for PDS.

Critical dynamic stress for the frozen subgrade soil

Triaxial dynamic tests at the temperature −6 °C were performed on frozen subgrade soil to study accumulative deformation and resilient deformation properties. Based on the shakedown theory, a reliable evaluation for the long-term serviceability of the frozen subgrade was further presented. The influences of confining pressure, dynamic stress amplitude, initial stress path and initial stress ratio on dynamic properties of frozen subgrade soil were analysed. The evolution features of accumulative permanent strain under cyclic loading were experimentally determinated. The boundary functions for plastic shakedown area and plastic creep area were further established. Critical dynamic stresses for the different deformation areas can be calculated by the experimental data and the proposal formula. The influences of consolidation pressure and initial stress ratio on critical dynamic stress were discussed in detail. The distribution characteristics (envelope line loci) of the critical dynamic stress were investigated in the mean stress-the shear stress space.

Effects of Farrowing Stall Layout on Piglet Productivity and Behavior

This large-scale field study evaluated the effects farrowing stall environment on piglet productivity and behavior. Three farrowing stall layouts were tested (T – traditional, C – expanded creep area, S – expanded sow area) in conjunction with one or two heat lamps (1HL or 2HL). Production data were collected on the number of piglets live at birth, percent stillborn, percent preweaning piglet mortality, percent over-lay (crushing), number of piglets weaned, average daily weight gain, and litter uniformity. The only productivity difference found was in percent stillborn (p = 0.045); however, it was of small magnitude and not of practical significance. Piglet behavior data were collected and processed with a custom imaging system. Each farrowing stall was divided into three regions: heated region directly below the heat lamp (Rheated), unheated regions of the creep (Rcreep), and sow stall region (Rsow). The proportion of piglets within each farrowing stall region were analyzed and compared on select days of lactation. Piglets in the 2HL treatment spent a significantly greater amount of time in Rheated compared to the 1Hl treatment (p&amp;lt;0.001). Time in Rheated, Rcreep, and Rsow were all influenced by stall layout (p&amp;lt;0.03). Results from this study indicate that dimensions of farrowing stall components do influence piglet behavior and the provision of a second heat lamp results in piglets increasing time spent in the heated area. These behavioral changes due to the farrowing stall environment did not result in differences in productivity. The addition of a second heat lamp or larger creep or sow stall areas produced changes in piglet behavior, but there were no significant changes in productivity metrics.&amp;nbsp; &amp;nbsp;

Modeling and Assessing Heat Transfer of Piglet Microclimates

High piglet pre-weaning mortality rates can be attributed to poor creep area microclimate resulting in negative productivity, welfare, and economic consequences. A piglet mechanistic steady-state thermal balance model was developed using previous models and expanded to assess (a) thermal interactions of multiple pigs and (b) conduction heat transfer. The piglet Effective Environment Temperature (EET) equation was also modified to incorporate piglet age (day 0 to 30) and a conduction heat transfer term. Model parameters were validated with empirical data consisting of the thermal component (dry-bulb temperature, Tdb; mean radiant temperature, TMR; airspeed, U; mat underside temperature, Tm) of the microclimate and dimension data of the piglets (i.e., body weight, length, height, width, and calculated surface area). Model results demonstrate that the common microclimate supplemental heat sources (heat mats and heat lamps; HL) can meet the needs of the piglets. The new EET was more consistent for a novel semi-enclosed heated microclimate (SEHM) in comparison to the HL. This demonstrates the benefit of precision technologies over manually adjusted supplemental heat sources. The experimental data and model results suggest further development of an ideal thermal index for piglet microclimates needs to account for variations of piglet health and body condition to be more applicable in industry.

Synthetic Olfactory Agonist Use in the Farrowing House to Reduce Sow Distress and Improve Piglet Survival.

Simple SummaryWithin intensive livestock industries, it is important to pursue the continual improvement of animal welfare. The farrowing crate design in most piggeries is currently the best way to optimize piglet welfare and reduce piglet mortality caused by being crushed by the sow. However, some studies have shown that restriction in a farrowing crate exacerbates sow distress at specific times during farrowing at lactation, which may compromise piglet survival. Therefore, there is a need to investigate strategies that may alleviate the stress experienced by the sow due to being confined. A synthetic olfactory agonist, a commercial product that mimics naturally occurring pheromones, previously reduced aggressive interactions in sows. Therefore, this product was investigated to determine its effectiveness at reducing sow stress and improving piglet survival during birth and lactation. We found no effect on the sow’s stress hormone levels between treatments in response to a stressor. However, first-litter sows experienced a decreased farrowing duration, but this did not extend to improvements in piglet pre-weaning survival. This synthetic olfactory agonist does not appear to be a suitable tool to reduce sow distress around birth or improve piglet pre-weaning survival.The aim of the study was to investigate if the application of a synthetic olfactory agonist (SOA) would reduce indicators of stress in sows, in response to a stressor prior to parturition, and if it would improve farrowing house performance of sows and their piglets. Two studies were conducted: an intensive study with 47 sows, either having their first or second litter (Control n = 24; SOA n = 23); and a commercial validation study with 418 sows, either having their first litter or have had multiple litters (Control n = 210; SOA n = 208). Within the intensive study, sows were housed with or without a synthetic olfactory agonist suspended in the creep area of the farrowing crate, whereas within the commercial validation study, sows were housed with or without a synthetic olfactory agonist suspended over the adjoining creep area of two farrowing crates. Within the intensive study, despite a discernible increase in cortisol concentration in response to a stressor (snout rope test), cortisol response was not different between treatments (p > 0.05). Farrowing duration in first-litter sows exposed to the SOA was decreased (p < 0.001) whilst there was no impact on farrowing duration in second litter sows. Piglets were not attracted by the SOA to increase their utilisation of the creep area and spent more time in proximity to the sow (p < 0.05). Within the commercial validation study, no impacts were seen on piglet production measures (p > 0.05). Largely the use of an SOA within the farrowing house did not impact the sow or her piglets in either the intensive study or commercial validation study. Based on these current results, the use of SOA within the farrowing house is not supported.

Detecting the Vegetation Change Related to the Creep of 2018 Baige Landslide in Jinsha River, SE Tibet Using SPOT Data

It is vital to monitor the post-seismic landslides economically and effectively in high-mountain regions for the long term. The landslide creep could cause a subtle change of the overlying vegetation after the earthquake, which will lead to the change of vegetation spectral characteristics in optical remote sensing data. The optical remote sensing technique can be used to monitor the landslide creep areas with dense vegetation in a large range at a low cost because it is easy to obtain multi-temporal, multiple-scale, and multi-spectral information. We identified and extracted the vegetation change area before the 2018 Baige landslide by the high-resolution optical remote sensing data. Firstly, the image fusion method was used to improve the accuracy of change detection. Then, vegetation coverage before the landslide was calculated. The vegetation change was identified, and qualitative and quantitative methods were used to analyze the spatio-temporal changes of vegetation coverage. Our results indicate that the creep distance of the landslide is about 50 m and the vegetation in the back scarp area and the main sliding area display a significant downward trend with time closing to the landslide comparing with that in the reference area. The vegetation change in the remote sensing image has an excellent spatio-temporal correlation with the landslide creep. This study provides a possible way and perspective for monitoring post-seismic landslide disasters.

Dimensions of the Suckling Pig

The rising prewean mortality rates in swine production are a great economic and production burden to the swine industry. The thermal environment for a piglet is commonly adapted to the piglet's specific needs with a key factor of surface area impacting all modes of heat transfer. The current standard for pig dimensions was originally accepted in 1968 and has yet to be updated with clear data from piglets during lactation. The objective of this study was to collect and evaluate the dimensions of body weight, length, height and width of piglets during lactation. Eight litters from geriatric sows (commercial cross breds) were utilized in this study with data collected every day from birth to weaning (23–32 days of age). The evaluation of the dimensions with effects of litter size and sex showed that sex of the piglet does not have a significant impact on dimensions while litter size does. The piglets in this study were smaller than the standard at birth, likely attributed to changes in genetics and an increase in total born. The results of this study showed a slight difference in dimension at the heavier weights to a study with nursery pigs however there are differences in genetics. The data and equations presented in this study will be valuable for the design of creep areas and supplemental heat sources to accommodate the size of modern piglets during lactation.

Effect of farrowing pen size on pre-weaning performance of piglets.

Litter sizes in commercial pig production have increased substantially over recent years; however, farrowing pen sizes have generally not changed over the same time period. The objective of this study was to evaluate the effect of farrowing pen size on piglet pre-weaning growth and mortality. Differences in pen size were created by varying the width of pens of the same length, increasing the creep area available to the piglets. The study used a total of 1,786 litters in a randomized complete block design to compare two farrowing pen size treatments (FPS): Standard (pen width 1.52 m) and Increased (pen width 1.68 m). Litter sizes were equalized across treatments (12.9 ± 1.95 piglets) at 24 h after birth using cross-fostering. Litter weights were collected at birth and weaning (21.3 ± 2.08 d); pre-weaning mortality was recorded. The experimental unit was the litter; models for statistical analysis included FPS and replicate. Farrowing pen size had no effect (P > 0.05) on litter size at birth (12.8 and 13.0 for the Standard and Increased FPS, respectively), after cross-fostering (12.9 for both treatments), or at weaning (11.2 and 11.3, respectively). There was no effect (P > 0.05) of FPS on total litter or average piglet weight at birth, after cross-fostering, and at weaning. These results suggest no benefit in piglet performance from increasing the width of farrowing pens. As litter sizes continue to increase in commercial production, further research is warranted to re-evaluate the impact of farrowing pen size on pre-weaning mortality.

Dynamic Earthquake Triggering in Southern California in High Resolution: Intensity, Time Decay, and Regional Variability

AbstractEarthquake triggering by seismic waves has been recognized as a phenomenon for nearly 30 years. However, our ability to study dynamic triggering has been limited by our ability to capture the triggering stresses accurately and record the resultant earthquakes. Here we use full waveforms from a dense seismic network and a modern, high‐resolution seismic catalog to measure triggering in Southern California from 2008 to 2017 based on interevent time ratios. We find that the fractional seismicity rate change, which we term triggering intensity or triggerability, as a function of peak strain change for the period of ∼20 s due to distant earthquakes is monotonically increasing and compatible with earlier measurements made with a disjoint data set from 1984 to 2008. A triggering strain of 1 microstrain is equivalent to the local productivity generated by an M1.8 earthquakes. This result implies that a prediction of seismicity rate changes can be made based on recorded ground shaking using the same formalism as currently used for aftershock prediction. For a teleseismic event, this small level of triggering occurs throughout the region and thus aggregates to a regional effect. We find that the triggering rate decays after the triggerer follows an Omori‐Utsu law, but at a much slower rate than a typical aftershock sequence. The slow decay rate suggests that an ancillary process such as creep or fluid flow must be part of dynamic triggering. The prevalence of triggering in areas of creep or fluid involvement reinforces this inference. A triggering cascade of secondary earthquakes is insufficient to explain the data.

Effects of farrowing stall layout and number of heat lamps on sow and piglet behavior

Farrowing stalls are used in the United States swine industry to reduce pre-weaning piglet mortality, enable efficient individual animal management, and decrease facility construction and operating costs. The quantity and quality of space provided for sows and piglets in farrowing stalls are important economic and welfare considerations. To further explore the impacts of farrowing stall space allocation, a large-scale field study was conducted to compare sow and piglet behavior when housed in three farrowing stall layouts (TSL – traditional stall layout, ECSL – expanded creep area stall layout, ESCSL – expanded sow and creep area stall layout) with either one or two heat lamps (1HL and 2HL, respectively). A computer vision system classified posture budgets and behaviors of 322 sows and piglet location for 324 litters. Linear mixed models were developed to compare behavior and piglet pre-weaning mortality metrics between experimental treatments. Results show sows in ESCSL spent more time lying compared to sows in ECSL (p = 0.028) and less time sitting compared to sows in TSL and ECSL (p < 0.01). Sows with the 2HL treatment had an increase in percentage lying (p = 0.017) and a decrease in percentage standing (p = 0.045) compared to sows with the 1HL treatment. Number of piglets, parity, and batch also influenced sow postural behavior (p < 0.05). Sow lying orientation was not impacted by HL treatment. Sow postures and behaviors were influenced by day of lactation (p < 0.001). Piglets with 2HL treatment spent more time in the heated region and less time in the creep and sow regions for all stall layouts on all days of lactation observed (p < 0.001). In the ESCSL, piglets had a greater percentage of time in the sow region compared to ECSL piglets (p < 0.004). Piglets did not spend equal percentages of time between the two creep or two HL regions (p < 0.001), and piglet location was correlated with sow lying orientation for most of the creep regions analyzed (p < 0.01). Increases in piglet pre-weaning mortality were correlated with increases in sow lying (p = 0.027) and decreases in standing (p = 0.025) and feeding (p < 0.001). However, correlations with sow posture were likely due to the impacts of day of lactation (p < 0.001). No correlations were found between piglet location and pre-weaning mortality (p> 0.05). Results can guide producers to consider wider sow areas in farrowing stalls to better meet sow behavioral needs and to include larger heated areas to meet piglet behavioral needs during lactation.

Novel supplemental heat source evaluation for swine farrowing stalls

The objectives of this study were to compare the production impact and energy usage between of a novel supplemental heat source (NSHS) and a conventional heat lamp (HL) in swine farrowing stalls. The NSHS evaluated has a parabolic shaped cover (provides heat to two creep areas) with clear curtains and an infrared heat source with proportional heat output control. Six farrowing turns in two farrowing rooms (24 farrowing stalls per room) were utilized in this study. The six NSHS (12 stall coverage) were randomly assigned to a farrowing stall for the duration of the study and HL assigned to the other 12 stalls. Piglets were weighed at 3 days and at 18 days of lactation using a litter scale and pre-weaning mortality was tracked using farm records. Energy usage was monitored using current sensors on each NSHS and HL energy was verified using a power meter. Data were collected on 113 NSHS and 101 HL litters and analyzed using a Mixed model in JMP 14. There was no statistical difference between the two treatments on ADG P&gt;0.10, there was a tendency for significance for pre-wean mortality P=0.08; NSHS 9.67% (SE=0.82) and HL 12.04% (SE 0.87); and a significant difference was noted in the laid-on mortalities P&lt; 0.05; NSHS 4.05% and HL 6.04%. There was a significant difference, P&lt; 0.01, in the energy usage (NSHS 3.25 kWh d-1, HL6 kWh d-1). Overall the NSHS had a tendency to reduce pre-wean mortality with a significant reduction in laid-on mortalities and reduce energy usage, though no impact was noted on ADG of the piglets.&nbsp;

Actual Conditions on the Land Creep Areas by the Analysis of Satellite Imagery

Actual Conditions on the Land Creep Areas by the Analysis of Satellite Imagery

Assessment of lying down behaviour in temporarily crated lactating sows

Temporary crating may be a more acceptable housing system for lactating sows than permanent crating from an animal welfare point of view. It remains unclear whether opening the crate leads to changes in sow lying down behaviour and piglet activity that may pose an increased risk of injury to piglets. This study aimed to assess whether the lying down behaviour of lactating sows housed in temporary crating changed shortly after removal of confinement, whether it was influenced by piglets' behaviour and age and whether sows preferentially used some support during lying down after crate opening. Sows (n = 13) were crated from 5 days pre partum to 3 days post partum. Their behaviours were recorded on video over a 24-h period both preceding and following crate opening, as well as over a 24-h period on day 25. The following behaviours were analysed: position and activity of the piglets when the sow lie down, duration of the lying down events, use of pen walls or crate bars as support when lying down; and position of the sow in the pen when lying down. Piglet mortality was assessed every day. Data were analysed in SAS using GLM. The duration of lying down events did not differ between the 24-h periods before and after opening the crate but increased on day 25 (P < 0.01). Similarly, the percentage of piglets in the danger zone did not differ between the 24-h periods before and after opening the crate, but increased on day 25 (P < 0.0001). The percentage of piglets in the creep area increased temporarily the day after the crate opening (P < 0.0001). Sows frequently utilised support when lying down, but less over the 24-h period after the crate opening compared to the two other periods (P < 0.001). A higher percentage of piglets in the creep area resulted in longer lying down events where the sow's snout was in contact with piglets located in the creep area (P < 0.05). The present study shows that opening the crate does have an immediate impact on lying down behaviour and piglet behaviour, but it does not pose an increased risk to piglets. Our results also indicate that piglet behaviour changed with age and influenced sow lying down behaviour. Finally, our findings further suggest that some available lying down support may be a very important feature of the pen during the whole lactation period.

152 Effects of a solar-powered cooling system on performance of heat-stressed lactating sows

Abstract We hypothesized that a solar-powered system designed to cool heat-stressed sows would improve sow performance and reduce use of fossil fuels in farrowing rooms. To test this hypothesis, we used two mirror-image, farrowing rooms equipped with 16 farrowing stalls each. Each farrowing stall in the COOLED room was equipped with a cooled flooring insert (Nooyen Manufacturing) under the sow and a single nipple drinker delivering chilled drinking water. Circulating water cooled by a water-source heat pump that was powered by a 20 kW photovoltaic solar array cooled the floor inserts (15 to 18°C) and chilled the drinking water (13 to 15°C). Heat harvested from sows partially warmed water (43 to 48°C) that circulated through pads in the piglet creep area. The CONTROL room was nearly identical to the COOLED room except there was no cooling and supplemental heat for piglets was provided by one heat lamp (125 W) per farrowing stall or an electric heating pad (Innovative Heating Technologies). Three farrowing groups were studied during summer and room heaters kept rooms above 24°C to ensure sows were heat stressed. Electric consumption in COOLED and CONTROL rooms was measured. Data were analyzed using Proc Glimmix with room treatment as a fixed effect and farrowing group as a random effect. The cooling system reduced sow respiration rate and body temperature (Table 1) which increased feed intake and reduced weight loss of sows over the 21-day lactation. However, the cooling system did not increase litter size or weight at weaning. Electricity use in the CONTROL room (26.4 kWh/d) was lower (P&amp;lt; 0.01) than the COOLED room (79.6 kWh/d). The solar array produced 91 kWh/d on average. In conclusion, the cooling system studied partially mitigated heat stress of lactating sows but did not improve sow performance and did not noticeably reduce consumption of fossil fuels.

46 Novel creep area heat source impact on pre-wean mortality occurrence

Abstract Pre-wean mortality (PWM) is a multifaceted problem facing the US swine industry. The objective of this study was to compare the occurrence of mortality and age of piglets between a novel heat source (HS; semi-enclosed heated microclimate; SEHM) and a conventional heat lamp setup. This study was conducted in two rooms at a 1,000 head commercial sow farm. Treatments were blocked by sow parity group (SPG; young, prime, and geriatric) over six farrowing cycles. Litters were cross fostered within HS treatment at 1 day of age. PWM, was the experimental unit, data were collected from the farm’s farrowing records and production accounting system. Age of the mortalities was categorized into four phases of lactation (PL) over the 20 d lactation (d0 to d3, d4 to d7, d8 to d11, and d12 to d20). Overall, there were 220 recorded instances of mortality. Data were analyzed in a CRBD using a PROC MIXED model in SAS (v9.4, SAS Inst., Cary, NC) and reported as LSMEANS with standard errors. The model included farrowing cycle as a random effect and the following fixed effects: HS, SPG, PL, HS*SPG, and HS*PL. Overall average PWM was 8.60%±0.80 for SEHM and 10.0%±0.70 for the heat lamps. There was no effect (P &amp;gt;0.05) of HS or HS*PL on PWM occurrence. There were significant effects of SPG (P=0.026), PL (P=0.05), and HS*SPG (P=0.036) on PWM occurrence. These data suggest that the HS type did not have an impact on the mortality rate or the timing of the mortality, indicating the mortalities that occurred had no relationship to HS. A limitation of this data set is the low sample size, thereby limiting the detection ability for this interaction. Further research into the impact of the HS is needed to expand the data set and to explore other popular HS effects on PWM.