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.

Effects of three husbandry systems on health, welfare and productivity of organic pigs.

Organic pig husbandry systems in Europe are diverse - ranging from indoor systems with concrete outside run (IN) to outdoor systems all year round (OUT) and combinations of both on one farm (POUT). As this diversity has rarely been taken into account in research projects on organic pig production, the aim of this study was to assess and compare pig health, welfare and productivity in these three systems. Animal health and welfare were assessed using direct observation and records of 22 animal-based measures, comprising 17 health-, 3 productivity- and 2 behavioural measures. These were collected in pregnant sows, weaners and fattening pigs during direct observations and from records within a cross-sectional study on 74 farms (IN: n = 34, POUT: n = 28, OUT: n = 12) in eight countries. Overall, prevalence of several animal health and welfare issues was low (e.g. median 0% for pigs needing hospitalisation, shoulder lesions, ectoparasites; <5% for runts, tail lesions, conjunctivitis). Exceptions in particular systems were respiratory problems in weaners and fatteners (IN: 60.0%, 66.7%; POUT: 66.7%, 60.0%), weaning diarrhoea (IN: 25.0%), and short tails in fatteners (IN: 6.5%, POUT: 2.3%). Total suckling piglet losses (recorded over a period of 12 months per farm) were high in all three systems (IN: 21.3%; POUT: 21.6; OUT: 19.2%). OUT had lower prevalences of respiratory problems, diarrhoea and lameness of sows. POUT farms in most cases kept sows outdoors and weaners and fatteners similar to IN farms, which was reflected in the results regarding several health and welfare parameters. It can be concluded, that European organic pigs kept in all three types of husbandry system showed a low prevalence of health and welfare problems as assessed by our methodology, but respiratory health and diarrhoea should be improved in weaners and fatteners kept indoors and total piglet mortality in all systems. The results provide benchmarks for organic pig producers and organisations which can be used in strategies to promote health and welfare improvement. Furthermore, in future research, the identified health and welfare issues (e.g. suckling piglet mortality, weaning diarrhoea) should be addressed, specifically considering effects of husbandry systems.

Effect of crate opening from day 3 postpartum to weaning on nursing and suckling behaviour in domestic pigs.

Temporary crating may be a more acceptable housing system for lactating sows than permanent crating and loose-housing because it combines benefits of both systems while reducing some of their limitations. It remains unclear whether nursing and sucking behaviour is influenced after crate opening. The aim of this study was to assess the short- (24 h post-crate opening) and long-term (day 25 postpartum (pp.)) effects of opening the farrowing crate from day 3 pp. to weaning on nursing and suckling behaviour. Sows were crated from 5 days prepartum either to weaning (permanently crated group; n = 14) or 3 days pp. (temporarily crated group; n = 13). Sows and their litters were observed on days 4 and 25. Duration of pre- and post-massages, nursing termination, number of piglets missing milk ejection and number of piglets fighting during pre- and post-massages were scored at 15-s intervals. Nursing success (i.e. with or without milk ejection) was also recorded. Data were analysed using PROC GLM and PROC GENMOD of SAS including housing, litter size and parity as fixed effects. Nursing behaviour did not differ between sows housed in temporary crates and those housed in permanent crates on days 4 and 25 pp., that is, same number of nutritive nursings (NNs), same proportion of non-NNs, same duration of post-massages and same proportion of termination of post-massages. There was only a housing effect on day 25; with sows having longer pre-massages in permanent crates (P < 0.05). Suckling behaviour was overall similar between treatments. There were no differences in the number of piglets attending pre- and post-massages, proportion of piglets fighting during pre-and post-massages and the proportion of piglets missing milk ejection on both days. The only housing effect was found on day 25 during which fewer piglets attended post-massages (P < 0.05) in permanent crates. Sows with larger litters terminated post-massages more often (P < 0.05), allowed shorter post-massages (P < 0.05) on day 4, and had more piglets miss milk ejection on days 4 and 25 (P < 0.05). In conclusion, the results of this study showed that housing had a very limited effect on nursing and suckling behaviour. Sow and piglet behaviours were not altered after crate opening (short-term effect) and nursing was to some extent calmer (shorter pre-massages and more piglets attended post-massages) in temporary crates on day 25. Increased litter size impaired nursing and suckling behaviour of sows and piglets independently of the housing system.

Impact of sow prepartum behavior on maternal behavior, piglet body weight gain, and mortality in farrowing pens and crates.

In the 24-h period prior to parturition, sows are active and motivated to perform nest-building behavior. The aim of this study was to investigate whether prepartum activity (nesting and postural changes) could predict maternal behavior 24 h postpartum, piglet mortality, and BW gain 24 h postpartum in farrowing pens and crates. Sows were randomly moved either to a farrowing pen ( = 20) or a farrowing crate ( = 18). Prepartum nest-building behavior (PRE-nesting) and prepartum postural changes (prepartum postural changes) were analyzed 24 h before the birth of the first piglet (BFP) and were divided into twelve 2-h intervals. Latency of the first suckling from the litter was observed after the birth of the last piglet. Udder accesses and piglet suckling were noted at 5-min intervals, using 1/0 sampling, during the first 24 h after BFP were counted. Piglet trapping, crushing, and total live-born mortality were measured during the first 72 h after BFP. Piglet BW gain was estimated 24 h after BFP. Increased PRE-nesting observed 2 h before BFP were associated with fewer suckling intervals in crates but not in pens ( < 0.01) as well as an increase in postural changes during parturition ( < 0.001) in both housings. A link between housing and PRE-postural changes was evident. An increase in the number of PRE-postural changes 2 h prior to BFP was associated with lower incidences of udder access in crates but not in pens ( < 0.05). A higher probability of piglet trapping was associated with increased PRE-nesting in the 2 to 4 h before BFP. No significant relationship between either PRE-nesting and postural changes and piglet BW gain and mortality was detected. Our results suggest that increased prepartum activity 2 h before parturition is associated with less suckling and less udder access in farrowing crates but not in farrowing pens. This suggests that the same sow behavior can have different consequences in pens vs. in crates. Future research should focus on nest-building activity, its relationship to endocrine indicators (e.g., oxytocin, cortisol) before parturition, and its potential long-lasting effects on subsequent maternal behaviors and piglet production.

The effect of farrowing environment and previous experience on the maternal behaviour of sows in indoor pens and outdoor huts.

Outdoor farrowing huts facilitate a less restricted maternal behaviour in sows compared with sows kept indoors in farrowing pens. The aim of our study was to investigate whether there are behavioural differences between primiparous sows kept outdoors in farrowing huts and indoors in pens, and whether the maternal behaviour during the second parity, when all sows were kept outdoors in farrowing huts, would differ between sows that have experienced the indoor or the outdoor environment, respectively, during their first parturition. A total of 26 Yorkshire×Swedish Landrace sows were studied. Of these, 11 sows were housed outdoors in farrowing huts during both parturitions (group=OUTOUT). The other 15 sows were kept indoors in a barn with single farrowing pens during their first parturition. During their second parturition, sows were kept outdoors in farrowing huts (group=INOUT). The behaviour was video recorded from 2 h prepartum to 48 h postpartum. The sows' responsiveness to playbacks of a piglet's screams was tested on days 2 to 3 postpartum. Parity 1: during the last 2 h prepartum, OUTOUT sows had a higher proportion of observations in the sternal lying position (P<0.01). During parturition, OUTOUT sows changed posture more often (P<0.05) and were lying less (P<0.05) than INOUT sows. All sows in both groups responded with 'lifting head' towards the playback of piglet scream, whereas 100% of OUTOUT sows and only 43% of INOUT sows thereafter were 'getting up' (P <0.01). Parity 2: There were no behavioural differences between INOUT and OUTOUT sows. In conclusion, it is not problematic for a second parity sow with initial maternal experience from an indoor farrowing pen to be kept outdoors in farrowing huts during its following farrowing.

Sow postural changes, responsiveness to piglet screams, and their impact on piglet mortality in pens and crates.

Free farrowing pens (pens) improve the welfare of sows but may increase sow activity and negatively influence piglet production. The aim of this study was to assess the effect of pens and crates on sow postural changes, piglet trapping, sow responses to piglet screams, piglet mortality, and piglet BW gain. It was predicted that provision of greater space (in pens) would increase not only the frequency of sow postural changes and the probability of trappisng but also sow responses to the screams of piglets; thus, the outcome would be no differences in fatal piglet crushing or overall mortality between the housing systems. Sows were randomly moved to either a farrowing pen (n = 20) or farrowing crate (n = 18). Sow behavior was recorded and analyzed for 72 h from the birth of the first piglet (BFP). Sow postural changes included rolling from a ventral to lateral position and vice versa and going from standing to sitting, standing to lying, and sitting to lying. Occurrences of piglet trapping and sow responsiveness to real crushing situations were analyzed. Sow responsiveness was assessed in response to audio playbacks (PB) of piglet screams on d 3 postpartum (48 to 72 h after BFP; PB crush calls) and real piglet crushing during the first 72 h after BFP (real crush calls). Piglet BW gain was estimated 24 h after BFP, piglet BW was recorded at weaning, and piglet crushing and piglet mortality were recorded during the 72 h after BFP. Data were analyzed using PROC MIXED and PROC GENMOD of SAS. Sows in pens showed more postural changes (P = 0.04) and tended to have greater incidences of piglet trapping (P = 0.07) than those in crates. Sow response to PB crush calls was greater in pens (P = 0.04) but did not differ for real crush calls between pens and crates (P = 0.62). There was no effect on the probability of piglet crushing (P = 0.38) and mortality (P = 0.41) during the 72 h after BFP nor in piglet mortality at weaning (P = 0.81) between pens and crates. Piglet BW gain at 24 h after BFP (P = 0.01) and piglet BW at weaning (P = 0.02) were greater in pens. Sows in pens showed more postural changes and tended to trap more piglets; however, the response to real crush calls did not differ between the two housing systems. Despite this, there was no increase in piglet crushing or mortality in pens, which might be influenced by the better piglet body condition observed in pens, which in turn could influence their ability to avoid crushing by the sow.

The effect of nesting material on the nest-building and maternal behavior of domestic sows and piglet production.

Nest building is an important part of maternal behavior in domestic pigs. The aim of the study was to assess the effect of nesting material sawdust vs. straw on sow behavior 24 h before and after birth of the first piglet (BFP) and piglet production. Sows, housed in farrowing crates, were randomly divided into 2 treatments: sawdust (n = 12) and straw (n = 13). Sawdust and straw were provided during the pre- and parturient period; after parturition, straw was given to both experimental groups. The prepartum nesting period (the time interval between the first and last nest-building records, including all other activity and resting before BFP), the nesting records (number of nesting records), nesting duration (duration of all nesting records), the start and termination of nesting, and the frequency of prepartum postural changes were collected 24 h before BFP. After BFP, number of nesting records and time to first sucking of the litter were collected. Frequency of postural changes and duration of udder access were collected 24 h after BFP during 3 time periods (during parturition, from the end of parturition to 12 h after BFP, and 12 to 24 h after BFP) and the frequency of nursing during 2 time periods (from the end of parturition to 12 h after BFP, and 12 to 24 h after BFP). Piglet BW gain and mortality were estimated 24 h after BFP. Data were analyzed using PROC MIXED and the probability of the piglet mortality using PROC GENMOD in SAS. Nesting material did not affect (P > 0.10) most of sow prepartum nesting behavior and had no effect (P > 0.10) on the prepartum frequency of postural changes. Sows from the sawdust treatment had a longer nesting period (P < 0.05), and nest building tended to start sooner (P < 0.10) than in the straw treatment. Nesting material had only a small effect on later maternal behavior. Sows from the straw treatment tended to have more nesting records after BFP (P < 0.10). The frequency of postural changes was affected by the interaction (P < 0.01) between treatments and time period: sow from the straw treatment had more postural changes during parturition compared with other time periods and sawdust treatment. No effect (P > 0.10) of the nesting material on piglet BW gain and mortality was found. The results suggest that sawdust compared with straw as nesting material provided to sows before and through parturition does not negatively affect maternal behavior during the 24 h before and after parturition or piglet production. Therefore, sawdust can be recommended as a suitable nesting material for farrowing sows when straw is not available.

Preweaning housing effects on behavior and physiological measures in pigs during the suckling and fattening periods.

The effect of the preweaning housing system on the stress response of pigs before weaning and during fattening was studied in 33 litters of domestic pigs. Three preweaning housing systems were compared: barren crate (standard farrowing crate without straw), enriched crate (20% larger crate, with straw), and as a control, a farrowing pen (pen, 60% larger than the barren crate, with straw). At 25 d of age, pigs were tested with an isolation test and 1 d later with a human approach test (HumanT). Pigs were weaned at 28 d of age. At 3 and 6 mo of age, pigs were tested with an isolation-human approach test. The latency and frequency of squeal calls and locomotor activity were analyzed for all 3 tests, whereas physical contact with the human was also analyzed for the HumanT and isolation-human approach test. At 6 mo of age, the pigs were transported to a slaughterhouse. One day before transport, immediately after transport, and 1 h after transport, saliva samples were taken for cortisol analysis. The pH of the LM was also measured 45 min after slaughter. Preweaning housing system affected (P < 0.05) the probability of squeal vocalizations, the latency of locomotion, and the duration of locomotion during the HumanT. Pigs from the enriched pens vocalized less, had a longer latency to move, and performed less overall locomotion than pigs from the barren crates. Preweaning housing system did not affect behavior of fattening pigs. Cortisol concentrations before and after transport were not affected by preweaning housing system. An interaction of cortisol concentrations and housing systems was observed between the control sample and the sample taken immediately after transport in pigs from the barren crates (P < 0.05) compared with pigs from the enriched housing systems. Meat from pigs reared in the barren crate tended to have lower pH (P < 0.10) and that of pigs reared in enriched crates had lower pH (P < 0.05) than meat of pigs reared in enriched pens. No differences were observed between pigs from barren or enriched crates. Our results suggest that enrichment of the preweaning environment through enlarged space, provision of straw, and free movement for the sow had a positive effect on the coping behavior of pigs before weaning and prevented an increase in salivary cortisol concentration immediately after transport and a decrease in meat pH 45 min postmortem at the age of 6 mo. Minimal enrichment of the commercial farrowing crate did not affect behavior and physiological measures in pigs before and after weaning.

Dimensions of maternal behaviour characteristics in domestic and wildxdomestic crossbred sows.

We examined the maternal behaviour of seven domestic and seven wildxdomestic primiparous sows during 10 days post partum to investigate two questions: (1) Did maternal behaviour change during domestication? (2) Can the interindividual variability of maternal behaviour be subsumed into a few dimensions of maternal temperament? We recorded: (a) willingness to leave the nest for food on Day 2; (b) reaction to a playback of squeezed piglet distress vocalisation on Day 2; (c) spontaneous nursing behaviour and spontaneous lying-down behaviour on Day 5 (from an overnight video recording); (d) reactions to playbacks of various piglet distress vocalisations on Day 6 and (e) reactions to a human in the 'nest' with piglets on Day 9. Moreover, data on baseline cortisol saliva concentration and its increase during a brief transportation period and novel environment challenge at the age of 5 months were available. Crossbred sows did not differ from domestic ones in any aspect of maternal behaviour except for a higher tendency to terminate final massage during nursings and a higher frequency of changing posture from lying to standing and back during the night. Factor analysis (based on correlation matrix of 11 behaviour and cortisol variables calculated for all 14 sows after removing the effect of breed) indicated that 82% of the variability in the data could be explained by three factors: first, 'calmness' on which low night time frequency of major posture changes, carefulness of lying-down behaviour and high propensity to remain in nursing position after milk ejection loaded positively while cortisol concentrations during challenge loaded negatively; second, 'protectiveness' with high loadings of the reaction scores to the playbacks of piglet distress calls and the human presence near the piglets; and third, 'nursing activity' which was strongly positively associated with nursing frequency, and negatively with the proportion of nutritive nursings and baseline cortisol values. The results indicate that most aspects of pig maternal behaviour have not been significantly changed by domestication and that substantial variability in maternal behaviour exists between sows, perhaps in the form of several behaviour characteristics which encompass both behaviour and endocrine profiles of the sows.

Prolactin and insulin levels in lactating sows in relation to nursing frequency.

It has been established that sows up- or down-regulate their milk production as the frequency of nursings is changed. The amount of udder massage by piglets might also influence milk production. To investigate whether these effects are associated with changes in prolactin or insulin levels, we enforced five sows each to nurse either every 35 min (MIN35) or every 70 min (MIN70) over a 26- to 28-hr period. Milk production was measured during the first 24 hr of this period. During the last three to four nursings, blood was collected every 5 min. Plasma prolactin levels increased after milk ejection (P < 0.05), whereas insulin levels increased only briefly in MIN70 sows. Sows nursing every 35 min had lower basal (P < 0.001) and maximal (P < 0.05) concentrations of insulin than MIN70 sows. There were no differences between the two groups in prolactin levels. Nursings with a postejection udder massage longer than 90 s tended to induce a higher increase in prolactin (P < 0.1) than nursings with a shorter massage. When the effects of imposed nursing frequency were removed, there was an across-sows positive residual correlation between average prolactin levels (P < 0.05) and the duration of post-ejection udder massage during the preceding 24 hr. We conclude that when milk production of a sow is changed by altering the nursing frequency within natural limits, the necessary alteration in catabolic state of energy metabolism may be associated with altered insulin levels. The duration of udder massage in a single nursing might have only a slight immediate impact on prolactin levels, but may influence prolactin levels more substantially if increased for a period of 24 hr.

The role of nursing frequency in milk production in domestic pigs.

We conducted three experiments to assess how nursing frequency affects milk output in early pig lactation. In Exp. 1, nursing behavior of 12 individually penned sows was recorded on d 1 through 3 postpartum. The milk output was measured using the weigh-suckle-weigh method. The spontaneous changes in the nursing frequency between d 1 and 2 were positively correlated with the changes in milk output (rS = .64), and the same was true for changes between d 2 and 3 (rS = .77). In Exp. 2, we forced sows, 7 to 8 d after parturition, to nurse every 35 min (10 sows) or every 70 min (eight sows) for 24 h. Sows nursing at short intervals had more nursings without milk ejection, but they gave 27% more milk and their litters gained 44% more weight during the experimental 24 h than sows nursing at long intervals. Litters nursed at long intervals massaged the udder longer after milk ejection. In Exp. 3, milk output was measured after intervals of 35, 50, and 70 min imposed in varied order on 11 experimental sows in the second week of lactation. In a separate recording of two 50-min nursings, we measured milk output from teats that were, or were not, sucked at the first nursing (i.e., giving within-sow comparison of 50 or 100 min). The milk output after 35, 70, and 100 min did not differ from that after 50 min, although there was a tendency for a slight increase with longer intervals. The results suggest that glands are refilled early after milk ejection and that the increase in milk available with prolonged intervals is only slight. As a result, it is the nursing frequency that plays a crucial role in adjusting the milk output.