Creep Area Research Articles

Comparison of novel infrared heating plates and conventional warm water plates for piglets' creep areas in farrowing pens

On a conventionally managed piglet-producing farm, novel infrared (IR) heating plates for piglets in the farrowing pens were tested for their suitability and compared with common warm-water (WW) heating plates. In total, 134 litters (summer n = 82, winter n = 52) were investigated, which were housed on IR or WW heating plates, respectively, with or without an extra cover plate (groups 1-4). To determine the influence of the different heat sources, the wound healing after castration and tail docking, the umbilical regression and the weight gain of the piglets were investigated. Additionally, the lying behavior of the piglets and the position of the sows' udder at the time of farrowing were examined with regard to the heating plates. Furthermore, the energy consumption and costs were compared. The piglets housed on IR heating plates displayed better wound healing after castration and tail docking than the piglets housed on WW plates. The best results were obtained in piglets kept on IR heating plates with an extra cover plate. In addition, significant benefits were demonstrated for the usage of IR heating plates regarding umbilical regression. The piglets kept on IR heating plates had a slightly better weight gain in summer, whereas there were no differences between groups during winter. The lying behavior in the creep areas was similar in all groups. In general, with increasing age the percentage of time piglets spent in the lying position on the plates decreased. The percentage of time lying on the plates was higher in winter than in summer. At farrowing, 74.6% of all investigated sows directed their udder towards the heating plates. With the IR heating plates, this behavior occurred significantly more often. The energy consumption (kWh) per litter was significantly lower for the IR heating plates (electric power) both in winter and summer in comparison with the WW plates (gas). The energy costs were comparable in summer, but were higher for the IR heating plates in winter. IR radiation of heating plates has a positive influence on wound healing after castration and tail docking as well as on umbilical regression. In addition, the lying behavior of sows at farrowing is influenced by the IR radiation. Despite the lower energy consumption of the IR heating plates, the most profitable system has to be determined individually for each farm.

VIZUALIZACE PITTINGOVÉHO PROCESU

The paper describes time-domain simulation of gear pitting damage using animation program. Key frames have been used to create illusion of motion. The animation uses experimental results of high-cycle fatigue of material. The fatigue damage occurs in the nominal creep area on the side of the gear tooth sample loaded with variable-positioned Hertz pressure. By applying the force, the pressure cumulates between two convex surfaces. This phenomenon results in material damage under of curved surfaces in contact. Moreover, further damage has been registered on the surface. This is due to exceeding the elastic-plastic state limit and development of „tabs“. The tabs serve as origin of surface micro cracks powered by shear stress and enclosed grease pressure as well. This deformation and extreme pressures of Pascal law contribute to elongation and growth of the surface micro crack. Non-homogenous parts of material volume support the initialization/development of the micro cracks as well. Resulting visualization of the tooth-side fatigue damage provides clear and easy-to-understand description of the damage development process right from the micro crack initialization to the final fragmentation due to pitting degradation.

Continuum simulation of the discharge of the granular silo

Using a continuum Navier-Stokes solver with the μ(I) flow law implemented to model the viscous behavior, and the discrete Contact Dynamics algorithm, the discharge of granular silos is simulated in two dimensions from the early stages of the discharge until complete release of the material. In both cases, the Beverloo scaling is recovered. We first do not attempt a quantitative comparison, but focus on the qualitative behavior of velocity and pressure at different locations in the flow. A good agreement for the velocity is obtained in the regions of rapid flows, while areas of slow creep are not entirely captured by the continuum model. The pressure field shows a general good agreement, while bulk deformations are found to be similar in both approaches. The influence of the parameters of the μ(I) flow law is systematically investigated, showing the importance of the dependence on the inertial number I to achieve quantitative agreement between continuum and discrete discharge. However, potential problems involving the systems size, the configuration and "non-local" effects, are suggested. Yet the general ability of the continuum model to reproduce qualitatively the granular behavior is found to be very encouraging.

Slow slip events: parameters, conditions of occurrence, and future research prospects

Slow slip events along faults and fractures are reviewed. Such inter-block displacements can be recorded at various scale levels and considered as transitional from quasi-stable (creep) to dynamic slip (earthquake). Such events include seismogenic slip along faults at velocities by one to three orders lower than those in case of 'normal' earthquakes, as well as aseismic slip cases. Discovering such events facilitates better understanding of how energy accumulated during deformation of the crust is released. Studying conditions and the evolution of transitional regimes can provide new important information on the structure and regularities of deformation in fault zones. Data from latest publications by different authors are consolidated, and the data analysis results are presented. Over 170 slow slip events are reviewed. Based on the consolidated data and modelling results obtained by the authors, relationships between parameters of the reviewed process are established, scale relations between the events are considered, and a first-approximation analysis is conducted for impacts of geomaterial characteristics on various deformation regimes. Low-frequency earthquake foci and slow slip sites are most typically located in zones of transition from stable creep areas to seismogenic segments of the discontinuity (Fig. 3) It can be logically supposed that in such transitional zones, the interface has specific frictional properties providing for a regime that can be termed as 'conditionally stable slip'. The duration of slow deformation events is roughly proportional to the released seismic moment, while such a ratio is close to self-similarity in case of 'normal' earthquakes (Fig. 4). In case of slow slip, an area of the displaced section is larger by many factors than the corresponding value for an earthquake with the same seismic moment, while an average displacement amplitude along the fault is significantly smaller (Figures 5 and 6). Velocities of slip propagation along the fault strike are variable from a few hundred metres to 20–30 km/day. Slip velocities tend to decrease with scale (Fig. 7). Various slip modes were realized in laboratory experiments with slider model. Main specific features of slow slip along faults were simulated in the laboratory conditions. Possibilities for implementation of different deformation regimes were mainly determined by structure of simulated fault gouge. At equal Coulombic strength, small variations of structural characteristics, such as granulometric composition, grain shape, presence of fluid and its viscosity, may critically impact the deformation mode (Fig. 12). As evidenced by the data consolidated and analysed in this article, conditionally stable regimes of deformation of crustal discontinuities are a common phenomenon. Studies of such transitional deformation regimes seem promising for establishment of regularities in generation and evolution of dynamic events, such earthquakes, tectonic rock bursts, and slope events.

Effects of creep grazing and stocking rate on forage selection and nutritive value of the diet for meat goat does and kids on grass/forb pasture

The effects of creep grazing and stocking rate (SR) on forage selection and nutritive value of the diet selected by Spanish does with Boer×Spanish kids and Boer×Spanish does with 3/4 Boer-1/4 Spanish kids were determined using grass/forb pastures. There were four treatments, each replicated, with three stocking rate (SR) treatments and one treatment involving creep grazing. Goats of both types were equally represented in all treatments. Each group of does and kids was allocated to 0.4ha pastures divided into four paddocks that were rotationally grazed in two cycles over a total of 76 days. The three SR were 4 does plus 8 kids (L), 6 does plus 12 kids (M), and 8 does plus 16 kids (H) per 0.4ha pasture. The creep grazing treatment (C) was at the high SR relative to the pasture area common to the does and kids. In this treatment, however, the kids had access to an additional area of a similar 0.4ha pasture sub-divided into four paddocks containing the leguminous tree mimosa (Albizia julibrissin Durazz) planted in rows. A direct observation and simulation method was used to characterize the diet selected by does and kids and obtain representative samples. These samples were evaluated in terms of their CP, NDF, ADF, and ADL concentrations and in vitro true DM digestibility (IVTDMD). There were no significant effects (P>0.10) of stocking rate on botanical composition of the diet selected or its nutritive value. Does and kids selected diets of similar botanical composition and nutritive value for the three treatments without a creep area. When kids were in a creep grazing area, 52.8% of their diet consisted of mimosa leaves leading to an improvement in the overall nutritional value of the diet relative to times when in the base grass/forb pasture (CP 21.9 vs. 19.8%, NDF 34.1 vs. 53.8%, ADF 21.4 vs. 27.5%, and IVTDMD 85.7 vs.79.9%). It was concluded that stocking rate had no impact on diet selection and the nutritive value of the diet of does or kids when grazing forage of low to medium quality. Kids with access to creep areas including mimosa trees, however, preferentially consumed mimosa leaves, thus improving the nutritive value of their diet.

An episodic creep-slip event detected by precise levelling surveys in the central part of the Longitudinal Valley Fault, eastern Taiwan, in 2011–2012

Abstract Precise levelling surveys were conducted across the central Longitudinal Valley Fault, eastern Taiwan, to understand the deformation of the transition zone between the stable fault creep area and the asperity area. In order to investigate the surface relationship between the fault creep area and the geological condition of the transition zone, we established levelling routes in the Yuli, Chike-san, and Reishuei areas. The Yuli area forms the geological boundary of the Lichi Melange Formation, which is composed of chaotic mudstones containing numerous exotic blocks of various sizes and lithologies. Along the Yuli route, located on the Lichi Melange, an uplift rate of 30 mm/yr was detected during the period 2010–2012, suggesting that aseismic fault creep might be continuing with long-term stability. Along the Chike-san route, a vertical deformation rate of 8 mm/yr was detected in the period 2010–2011. However, a large deformation with an uplift rate of 40 mm/yr was detected in the period 2011–2012. Along the Reisuei route, we detected a deformation of 8 mm/yr in the period 2011–2012. A two-dimensional single-fault model was developed to discuss the slip distributions in the periods 2010–2011 and 2011–2012. Relatively large slip rates were estimated at two parts of the fault plane—one at a depth of ~ 1.5 km and another at a depth of ~ 4 km—in both periods. Because both parts of the fault plane show approximately the same slip distribution, we believe that the detected deformation resulted from an episodic acceleration event of creeping slip. The northern limit of the stable creep area may be the Yuli area. The episodic creep event occurred in the transition zone between the stable fault creep area and the asperity area. The boundary between the stable creep area and the episodic creep area is consistent with the geological boundary of the Lichi Melange Formation.

Avoiding hypothermia in neonatal pigs: Effect of duration of floor heating at different room temperatures1

The effect of different farrowing room temperatures (15, 20, or 25°C), combined with floor heating (FH) at the birth site, on the postnatal rectal temperature of pigs, use of creep area, and latency to first colostrum uptake was investigated with 61 litters born by loose-housed sows. Pig rectal temperature was measured at birth, as well as at 0.25, 0.5, 1, 1.5, 2, 3, 4, 12, 24, and 48 h after birth. The drop in rectal temperature from birth to 0.5 h postpartum was less (P<0.05) at room temperature of 25°C compared with 20 and 15°C. Minimum rectal temperature was less (P<0.001) at 15°C than either 20 or 25°C, and the time it took for rectal temperature to increase above 37°C was longer (P<0.05) when room temperature was 15°C than 20 and 25°C. Rectal temperatures at 24 (P<0.001) and 48 h (P<0.05) postpartum were also lower at room temperature of 15°C than 20 and 25°C. Duration of FH (12 or 48 h) did not influence (P>0.28) the rectal temperature at 24 or 48 h after birth. More pigs used the creep area 12 to 60 h after birth of the first pig at a room temperature of 15°C with 12 h FH compared with all other treatments. During the latter part of this period, more pigs stayed in the creep area also at 20°C with 12 h FH. After 60 h, more pigs (P<0.01) used the creep area at low compared with high room temperatures (15°C>20°C>25°C). Odds ratio of pigs dying before they had suckled was 6.8 times greater (P=0.03) at 15 than 25°C (95% CI of 1.3 to 35.5), whereas the odds ratio of dying during the first 7 d was 1.6 greater (P=0.05) for 48 vs. 12 h of FH (95% CI of 1.0 to 2.57), mainly due to more pigs being crushed. In conclusion, FH for 48 h was no more favorable than 12 h for pigs because the risk of hypothermia was equal in the 2 treatments, and the risk of dying increased with the longer FH duration. Increasing the room temperature to 25°C reduced hypothermia and the risk of pigs dying before colostrum intake.

PSInSAR displacements related to soil creep and rainfall intensities in the Alpine foreland of western Slovenia

An assessment of the relationship between displacement rates of objects located in areas of active soil creep and rainfall intensities was performed using a permanent-scatterer technique of synthetic aperture radar interferometry. The study focussed on two areas in central Slovenia during the period between April 1992 and December 2000. Based on field assessments, six permanent scatterers for one area and 11 scatterers for the other were selected for analysis from >4300 available permanent scatterers. Displacement rates related to creeping processes were compared with the different durations and intensities of rain in order to assess the threshold values that initiate the creeping process and to assess the relationship between the speed of the movement and the precipitation events. Although the permanent scatterer displacement data contain much noise, our results indicate that soil creep is induced by 20mm of rain in 1day or 50mm of rain in 3days, causing an average elevation decrease of 0.5 and 1mm, respectively. The elevation decreases due to soil creep were observed as instantaneous events, since no increased correlations were observed when a time lag between precipitation and displacement was taken into account. Models developed in this research indicated very similar rates of tectonic uplift for the two research areas in the event of no rain, and these rates were found to be faster than the regional tectonic uplift. This suggests that areas with high rates of tectonic uplift and areas of active soil creep may be related.

Acute behavioural responses to tail docking in piglets – Effects of increasing docking length?

Abstract Background and aim Tail docking has been suggested as an animal model of neuropathy and pain based on findings of relations between the degree of neuroma formation and the docking length. We examined effects of docking length on behaviour of piglets during and 6 h after tail docking. Methods Piglets were tail docked 2–4 d post-partum. We used 53 piglets and four treatments: intact (I), removal of either 25 (Q), 50 (H) or 75% (T) of the tail. The piglets were kept with sow and littermates under production conditions, and docked using a gas-heated instrument. Behaviour was observed during docking and for the following 6 h. Results Tail docking led to behavioural changes, the magnitude of which to some extend depended on docking length. Increased docking length led to increased intra-procedural vocalization score (0, 0.6 ± 0.2, 1.4 ± 0.2 and 1.4 ± 0.2 for I, Q, H and T, respectively, P&lt;0.001). In the initial 6h, increased docking length led to increased time spent in the heated creep area (2 ± 1%, 15 ± 6%, 18±8% and 30±6% for I, Q, H and T, respectively; P&lt;0.05). Piglet posture was affected as well, showing that increased docking length led to decreased lying (71 ± 2%, 68 ± 2%, 61 ± 2% and 61 ± 2% for I, Q, H and T, respectively, P&lt;0.01) and increased time spent active (24 ± 2%, 23 ± 2%, 32 ± 2% and 30 ± 3% for I, Q, H and T, respectively, P&lt; 0.05). Pain specific behaviours such as trembling or tail flicking were registered and occurred in 5 ± 1% and 9 ± 1% of observations. However, no effects of docking length could be shown. Conclusions Piglets responded behaviourally to tail docking. Increasing docking length led to increased pain responses such as intra-procedural vocalizations, hiding behaviour and reduced rest, indicative of increased pain. These results confirm earlier reports suggesting that tail docking might be suitable as an animal model for neuropathy and pain.

Comportamento suíno influenciado por dois modelos de maternidade

Neste estudo foram avaliados dois modelos de maternidade. O modelo um (MOD 1) era formado por duas salas similares, cada sala composta de oito celas parideiras individuais. O escamoteador era de alvenaria com tampa de madeira e aquecimento no piso, por resistência elétrica. A sala do modelo dois (MOD 2), continha 20 celas parideiras individuais, dentre as quais foram avaliadas apenas 16. Os escamoteadores eram de madeira com aquecimento por lâmpada incandescente de 60 W. Foram avaliadas as condições de ambiente das salas e do interior dos escamoteadores. O comportamento dos leitões foi avaliado no ambiente das salas e nos escamoteadores. O ambiente mais favorável para os leitões foi no MOD 1 com o maior percentual de valores de temperatura e umidade dentro da zona de conforto. A temperatura do piso do escamoteador do MOD 2 obteve os melhores resultados. O comportamento mais observado nos leitões foi o de permanecerem no interior do escamoteador e deitados aglomerado. A presente área de estudo carece de mais pesquisas que levem em consideração variáveis que possam afetar a temperatura no interior dos escamoteadores, como o material utilizado na construção dos abrigos e a troca de calor entre os leitões.

Haltung von Sauen in Bewegungsbuchten - Entwicklung der Nürtinger e-motion-Bucht

Farrowing and nursing sows are commonly restrained in farrowing crates. Detracting from the advantages of this restraint method are considerable disadvantages in the form of ethopathic and technopathic behaviour, higher MMA susceptibility as well as increased labour and associated costs. The Nurtinger e-motion farrowing pen was developed during 14 breeding cycles with 11 to 15 sows, starting off from the Swiss-developed Schmid and FAT-2 pens and the Nurtinger System’s Raidwanger farrowing pen. The resultant design offers benefits for both livestock and personnel with the sow area featuring a separate lying area with rubber mat and a perforated grid area and with an additional creep area for the piglets. The Nurtinger e-motion pen with Kraiburg rubber mat fulfils the requirements of a modern farrowing pen. In terms of labour efficiency the concept is superior not only to other types of loose farrowing pens but also to the farrowing crate.

Management routines at the time of farrowing—effects on teat success and postnatal piglet mortality from loose housed sows

The aim of this experiment was to study the effects of six different management routines at the time of farrowing on latency to first suckle, heat loss, weight gain and postnatal mortality. A total of 872 piglets from 67 loose housed sows in a commercial pig unit were subjected to one of six different management routines: control (CON n = 14), no treatment; (CREEP n = 13), placed in creep area; (UDDER n = 10), placed at the udder; (DRY n = 10), dried and placed back where found; (DRYCREEP n = 9), dried and placed in creep area; and (DRYUDD n = 11), dried and placed at the udder. The latency from birth to first suckle, rectal temperature at birth, 2 hours and 24 hours were measured for each piglet, in addition to weight at birth, 2 hours and 24 hours. Latency from birth to first suckle was shortest for piglets in the DRYUDD treatment, followed by the UDDER treatment ( P < 0.001). More live born piglets died in the UDDER treatment compared to the other treatments ( P < 0.001), but there were no other differences between the treatments with regards to postnatal mortality. There was a significant interaction between treatment and batch, with a significantly lower postnatal mortality in the DRYUDD treatment than CON in batch 2, but not in batch 1 and 3 ( P < 0.001). Large litter sizes resulted in a higher postnatal mortality in all treatments ( P < 0.001), and tended to reduce latency to suckle ( P < 0.1). In conclusion, drying the piglets after birth and placing them at the udder resulted in reduced postnatal mortality in batch 2, but not in the other two batches. Despite having the largest mean litter size of the treatments, less than 10% of the piglets in DRYUDD died, which is remarkably low for loose housed sows. Regardless of treatment, several piglet-related factors were found to be highly important for postnatal mortality, such as the number of functional teats per piglet ( P < 0.001), birth weight ( P < 0.001), the latency from birth to first suckle ( P < 0.01), and rectal temperature at 2 hours after birth ( P < 0.001).

P94 How do vascular smooth muscle cell-derived chemokines affect trophoblast cell function?

A critical problem of small punch test is determining the relation between this test and the conventional uniaxial test. In high-temperature creep conditions studied by constant-force variant of small punch test, this problem is often approached empirically by comparing force in small punch test and the applied stress in conventional creep test of the same duration, i.e. of the same time to fracture. A different approach is used in the evaluation of constant-rate small punch test: the force is normalized by the square of specimen thickness or, recently, by the product of the specimen thickness and a relevant deflection. Modifications of this advanced approach in the creep area are examined in the present paper. The deflection observed at fracture of specimen in small punch creep test is taken as a starting normalization quantity. The suggested correlations are illustrated by means of data obtained by creep testing of steels usually employed in power plants (P91, P92) or proposed for heavy-duty service (Eurofer’97).

Increasing the piglets’ use of the creep area—A battle against biology?

Indoor farrowing systems are based upon the assumption that the newborn piglets will leave their mother after suckling and enter a heated creep area, but newborn piglets are motivated to remain close to the sow. Several creep area features attractive to piglets were used to attempt to increase time spent in the creep area the first two days after birth and to find out whether increased time spent in the creep area would affect early piglet mortality in farrowing pens. Forty-six loose-housed sows and their litters kept in individual farrowing pens were subjected to one of three creep area treatments; (1) control (CON); concrete floor in the creep area, (2) bedding (BED); an insulated and soft bedding in the creep area and (3) HUT; an insulated and soft bedding in the creep area plus an additional wall to increase the heat conserving capacity in the creep area. The pens were video-recorded from 0–72 h after birth and analysis was conducted from 08:00 h to 14:00 h and from 20:00 h to 02:00 h on each day. The attempts to make the creep area attractive did not increase the use of the creep area; piglets in the hut treatment spent less time in the creep area and more time resting near the sow than piglets in the CON and BED treatment. Improving the thermal comfort and increase the layer of bedding in the creep area did not increase time spent away from the sow, nor did it reduce piglet mortality. Quality of the creep area thus appears to have little impact on piglet survival.

Geodetically Inferred Coseismic and Postseismic Slip due to the M 5.4 31 October 2007 Alum Rock Earthquake

On 31 October 2007 the M 5.4 Alum Rock earthquake occurred near the junction between the Hayward and Calaveras faults in the San Francisco Bay Area, producing coseismic and postseismic displacements recorded by 10 continuously operating Global Positioning System (GPS) instruments. The cumulative postseismic displacements over the four months following the earthquake are linearly related to the cumulative number of aftershocks and are comparable in magnitude to the coseismic displacements. The postseismic signal suggests that, in addition to afterslip at seismogenic depths, localized right-lateral/reverse slip occurred on dipping shallow fault surfaces southwest of the Calaveras. The spatial distribution of slip inferred by inverting the GPS data is compatible with a model in which moderate Calaveras fault earthquakes rupture locked patches surrounded by areas of creep, afterslip, and microseismicity (Oppenheimer et al. , 1990). If this model and existing Calaveras fault slip rate estimates are correct, a slip deficit remains on the 2007 Alum Rock rupture patch that may be made up by aseismic slip or slip in larger earthquakes. Recent studies (e.g., Manaker et al. , 2005) suggest that at depth the Hayward and central Calaveras faults connect via a simple continuous surface illuminated by the Mission Seismic Trend (MST), implying that a damaging earthquake rupture could involve both faults (Graymer et al. , 2008). If this geometry is correct, the combined coseismic and postseismic slip we infer for the 2007 Alum Rock event predicts static Coulomb stress increases of ∼0.6 bar on the MST surface and on the northern Calaveras fault ∼5 km northwest of the Alum Rock hypocenter.

Piglet use of the creep area—Effects of breeding value and farrowing environment

The objective of this study was to investigate piglet use of the creep area, comparing litters of sows with a high vs. low breeding value for piglet survival in the first 5 days postpartum, that were either housed in crates or individual pens during farrowing and lactation. Seventy-five Yorkshire × Danish Landrace sows were video recorded for 4 days after farrowing, and the analysis was conducted using instantaneous sampling every 10 min commencing 24 h after the birth of the first piglet for a period of 72 h. Breeding value for piglet survival had no effect on piglet use of the creep area or time spent in any location of the farrowing environment. Farrowing environment had significant effects on piglet location; during all days there were significantly more piglets in the creep area in the crates compared to the pens ( P < 0.01), and this difference was larger at 24–48 h than at 49–72 h and at 73–96 h after birth ( P < 0.05). Piglets in pens spent significantly more time resting near the sow, excluded nursing ( P < 0.001), and this percentage decreased over time after farrowing ( P < 0.001) in both the crates and the pens. In conclusion, piglet use of the creep area was higher in the crate compared to the pen particularly during the second day of life. This may partly be due to a much larger proportion of uncomfortable, slatted floor in the crates, and the shorter distance from the sow to the creep area in the crate.

Influence of straw length, sow behaviour and room temperature on the incidence of dangerous situations for piglets in a loose farrowing system

Crushing of piglets can be a major problem in loose-housing farrowing systems. In this study, we investigated the influence of straw of different lengths provided as nest-building material, sow behaviour and room temperature on the incidence of dangerous situations for the piglets. Piglets were defined as in danger of being crushed if they were trapped by the sow's body or if they jumped aside in response to the lying down or rolling behaviour of the sow. The behaviour of 22 Large White sows and their piglets was video-recorded from 10 h before farrowing until 72 h afterwards. The sows were kept in loose farrowing pens equipped with a creep area and a heating lamp. For a period of 5 days (48 h before the expected farrowing until 72 h after farrowing) 11 sows each had access to either 2 kg of long-stemmed straw or 2 kg of short-cut straw provided on the floor. Sows in pens with short-cut straw manipulated the pen equipment more frequently during the 10 h before farrowing than sows in pens with long-stemmed straw ( P = 0.02). The number of dangerous situations was associated positively with the time the sow spent nest-building during farrowing ( P < 0.01) and with the occurrence of events in which she laid down laterally without leaning against a wall and with more than two piglets present during the first 3 days after farrowing ( P = 0.04). The incidence of dangerous situations also decreased over the first days after farrowing ( P < 0.001), increased with the time the sow spent moving around before lying down ( P = 0.04), and was inversely related to the duration of the lying-down movement ( P = 0.05). Moreover, the more piglets there were present during a lying-down movement the higher was the incidence ( P = 0.02), especially if they were not grouped on only one side of the sow's body ( P = 0.03). Room temperature was associated positively with the time it took the piglets to get to the creep area after birth ( P = 0.01) and negatively with the time they spent there ( P = 0.02) but did not affect the incidence of dangerous situations. Straw length had no significant influence on the total pre-weaning piglet mortality or the proportion of piglets crushed. In conclusion, we found that sow behaviour was hardly affected by straw length but had a major influence on the occurrence of situations with a risk of crushing piglets.

Drying and warming immediately after birth may reduce piglet mortality in loose-housed sows

The aim of the present experiment was to investigate the effects of placing newborn piglets under the heat lamp or both drying and placing them under the heat lamp on piglet mortality. Sixty-seven healthy (Landrace × Yorkshire) sows were divided equally into three different experimental groups: a control group where the farrowings occurred without supervision from the farmer (C; n = 23 litters), another group where the piglets were placed under the heat lamp in the creep area immediately after birth (HL; n = 22 litters) and a third group where the piglets were dried with straw and paper towels followed by placing them under the heat lamp in the creep area immediately after birth (DHL; n = 22 litters). The sows were individually loose-housed in farrowing pens during farrowing and lactation. The piglets were not closed inside the creep area, but were free to move around in the pen. The routines in the experimental groups required the stock person to attend the farrowings from the onset of birth of the first piglet until the last piglet was born. All the dead piglets were weighed and subjected to a post mortem examination at the farm to ascertain the causes of death. Postnatal mortality (% of live born) was significantly lower in the HL and DHL groups than in the control group (P < 0.0001). This was significant concerning all causes of mortality. Compared to the control group, crushing occurred in significantly fewer litters when the piglets were both dried and placed under the heat lamp (P < 0.05). In the DHL treatment, crushing of one or more piglets by the sow occurred in only 13.6% of the litters, whereas this was increased to 34.8% in the HL and to 47.9% in the control group, respectively. All causes of death, except the proportion of stillborn piglets, increased significantly with increasing litter size. Because of the relatively large potential that these rather simple routines may have to improve piglet survival, different types of management or human interference around the time of farrowing should be compared on a larger scale, both experimentally and on commercial farms.

Effect of infrared temperature on thermoregulatory behaviour in suckling piglets

The objective of this study was to investigate the effect of infrared (IR) temperature on thermoregulatory behaviour in suckling piglets in the first 3 weeks after farrowing. A total of 10 piglets from each of the 16 litters were exposed to recommended IR temperature conditions at 1, 2 and 3 weeks of age, with a mild offset (4°C) in IR temperature during the first experiment and a more challenging offset (8°C) during the second experiment. Digital photos were taken when all piglets had settled in the creep area, and the lying posture and huddling behaviour were analysed. A lying posture score and a huddling score was calculated by multiplying the number of piglets in each category with a given value for each category, based on different lying postures and different degrees of huddling behaviour. With a 4°C change in IR temperature, the piglets tended to alter their lying posture, while an 8°C change had a significant effect on lying posture (P < 0.01). A change in IR temperature of 4°C had no effect on the degree of huddling. The huddling score decreased significantly with 8°C change in IR temperature (P < 0.05). Postural changes, rather than changes in degree of huddling were the preferred thermoregulatory strategy for suckling piglets.

Carefulness and flexibility of lying down behaviour in sows during 24 h post-partum in relation to piglet position

This study focused on sow lying down behaviour and on the flexibility of her pre-lying behaviour, both of which are supposed to be crucially linked to piglet crushing. First, during 24 h after the birth of the first piglet (BFP) changes in the frequency of standing-to-lying events were investigated in 18 sows housed in farrowing crates. The 24 h were split into four time periods for use in the statistical analyses (0–2 h, 2.01–6.00 h, 6.01–16.00 h, 16.01–24.00 h). A carefulness score which includes sniffing, rooting, pawing, lying down vertically and “no piglets in danger zone” was calculated for each standing-to-lying event. We also determined whether a pre-lying behaviour index (consisting of the incidence of sniffing, rooting and pawing) and its duration were influenced by piglet location (sow area vs. creep area) and piglet clustering. Every crushing event was noted. The carefulness score was lower 6 h after BFP then increased and remained stable until the end of the 24 h. Sows changed their pre-lying behaviour independently from the time period but not from piglet position as sows showed more and longer pre-lying behaviours when piglets were in the sow area and/or when piglets were already clustered at the start of the pre-lying behaviour, independent of where they clustered. Although the pre-lying behaviour increased the probability of clustering, it did not affect the probability that piglets moved from the sow to the creep area immediately before lying down. A higher carefulness score as well as “no piglets in the danger zone” were associated with a lower probability of crushing, whereas the pre-lying behaviour had no influence. The results emphasize that sows are flexible in the pre-lying behaviour during this early piglet age. Further research should focus on factors which decrease the probability that piglets are present in the danger zone and specifically on sow and piglets communication during pre-lying behaviour.