Individual piglets' contribution to the development of tail biting

Conflicting hypotheses exist about the contribution of individual pigs to the development of a tail-biting outbreak, but there is limited quantitative information to support or dismiss them. This study aims to quantify the development of tail-biting behaviour at pen and individual piglet level, before and after the first visible tail damage. Video recordings of 14 pens with tail-biting outbreaks and individually marked weaned piglets were used to observe tail-biting incidents (TBIs; piglet biting a penmate's tail). When visible tail damage was first observed in a pen (i.e. day of tail biting outbreak; D0), the video recordings of the previous 6 (till D-6) and the following 6 days (till D6) were analysed every other day for TBIs and the identities of the biter and bitten piglet were recorded. The average TBIs per individual piglet (within each pen) per observation day were analysed to quantify the development of tail-biting behaviour and to identify pronounced biters and/or bitten piglets. The (absence of) coherence for TBIs in a pen was used to test whether biters preferred a specific penmate. There was an exponential increase in the intensity (linear on log scale) of the TBIs from an average of 0.7 bites/h at D-6 to 2.3 bites/h at D6. An additional negative quadratic component suggests that a plateau for tail-biting behaviour was reached by the end of the observation period. Before any visible tail damage was observed (i.e. before D0), 82% of the piglets performed and 96% of them received tail bites. After D0, the figures were 99% and 100%, respectively. One or a few pronounced biters could be identified in almost all pens. These biters already showed more tail biting at D-6 than their penmates. Furthermore, these biters showed a greater increase in tail-biting behaviour during the observation period than the average scores of their penmates. In contrast, there was no apparent increase in the receipt of bites among the piglets that had already been bitten more than their penmates at D-6. Finally, there was no significant coherence between biters and bitten piglets, indicating that biters showed no preference for biting particular penmates, even when some of them had a damaged tail. These results show that, by using observations of TBIs, possible biters or bitten piglets can already be identified 6 days before tail damage is first apparent in a pen.     

Tail docking in pigs: acute physiological and behavioural responses

Tail docking of piglets is a routine procedure on farms to control tail-biting behaviour; however, docking can cause an acute stress response. The objectives of this research were to determine the stress responses to tail docking in piglets and to compare two methods of tail docking; cautery iron (CAUT) and the more commonly used blunt trauma cutters (BT). At approximately 6 days of age, piglets were tail docked using CAUT (n = 20), BT (n = 20) or sham tail docked with their tails remaining intact (CON; n = 40). Blood samples were taken prior to tail docking and at 30, 60 and 90 min after tail docking to evaluate the effect of tail docking on white blood cell (WBC) measures and cortisol concentrations. The above experiment was repeated to observe behaviour without the periodic blood sampling, so as not to confound the effects of blood sampling on piglet behaviour. Piglet behaviour was recorded in the farrowing crate using 1 min scan-samples via live observations for 60 min prior to and 90 min after tail docking. Total WBC counts were reduced (P > 0.05) among BT and CAUT compared with CON piglets 30 min after tail docking. Cortisol concentrations were higher (P < 0.01) among BT compared with CON and CAUT piglets 60 min after tail docking. Cautery and BT-docked piglets spent more (P < 0.05) time posterior scooting compared with CON piglets between 0 and 15 min, and 31 and 45 min after tail docking. Piglets tail docked using CAUT and BT tended to spend more (P < 0.07) time sitting than CON piglets between 0 and 15 min post tail docking. Elevated blood cortisol can be reduced by the use of the CAUT rather than the BT method of tail docking. Although the tail docking-induced rise in cortisol was prevented by using CAUT, the behavioural response to BT and CAUT docking methods was similar.     

Tail Biting in Pigs: Blood Serotonin and Fearfulness as Pieces of the Puzzle?

Tail biting in pigs is a widespread problem in intensive pig farming. The tendency to develop this damaging behaviour has been suggested to relate to serotonergic functioning and personality characteristics of pigs. We investigated whether tail biting in pigs can be associated with blood serotonin and with their behavioural and physiological responses to novelty. Pigs (n = 480) were born in conventional farrowing pens and after weaning at four weeks of age they were either housed barren (B) or in straw-enriched (E) pens. Individual pigs were exposed to a back test and novel environment test before weaning, and after weaning to a novel object (i.e. bucket) test in an unfamiliar arena. A Principal Component Analysis on behaviours during the tests and salivary cortisol (novel object test only) revealed five factors for both housing systems, labeled ‘Early life exploration’, ‘Near bucket’, ‘Cortisol’, ‘Vocalizations & standing alert’, and ‘Back test activity’. Blood samples were taken at 8, 9 and 22 weeks of age to determine blood platelet serotonin. In different phases of life, pigs were classified as tail biter/non-tail biter based on tail biting behaviour, and as victim/non-victim based on tail wounds. A combination of both classifications resulted in four pig types: biters, victims, biter/victims, and neutrals. Generally, only in phases of life during which pigs were classified as tail biters, they seemed to have lower blood platelet serotonin storage and higher blood platelet uptake velocities. Victims also seemed to have lower blood serotonin storage. Additionally, in B housing, tail biters seemed to consistently have lower scores of the factor ‘Near bucket’, possibly indicating a higher fearfulness in tail biters. Further research is needed to elucidate the nature of the relationship between peripheral 5-HT, fearfulness and tail biting, and to develop successful strategies and interventions to prevent and reduce tail biting.     

Higher light intensity and mat temperature attract piglets to creep areas in farrowing pens

Loose farrowing pens have been considered as alternatives to crates to enhance sow welfare. A major concern with pen systems is often higher piglet pre-weaning mortality, especially due to crushing by the sow. An optimal management of light and mat surface temperature may promote greater piglet use of the creep, which has been associated with reduced piglet crushing. A total of 108 sows and their piglets were studied in sow welfare and piglet protection pens on a commercial piggery, across two replicates. Sows were randomly assigned to pens arranged within two creep treatments (bright creep: 300 lx v. dark creep: 4 lx), considering mat temperature as a covariate. Twelve sows and their litters in each treatment (24 in total) had their behaviour continuously recorded for 72-h postpartum (pp), and four focal piglets per litter were weighed on the first and third days pp. In situ behaviour observations were performed daily (from 0800 to 1700 h) on all sows and their litters, every 15 min over 72-h pp to record piglet time spent in the creep, latency to enter the creep for the first time, latency for the litter to remain in the creep for at least 10 min, and piglet and sow use of pen areas immediately in front of (A2) and farthest from the creep (A3). Piglets with access to bright creeps spent on average 7.2% more time (P<0.01) in the creeps than piglets in pens with Dark creeps. In addition, for each degree increase in mat temperature, piglets spent on average 2.1% more time (P<0.01) in the creep. Piglets in pens with bright creeps spent less time in A2 (P=0.04) and the least time in A3 (P=0.01). Light or mat temperature did not affect sow use of pen areas or piglet weight gain. Piglets with bright creeps tended (P=0.06) to take longer to enter the creep for the first time after birth, but the latency for 30.0% of the litter to remain clustered for 10 min tended (P=0.08) to be shorter in bright compared to dark creeps. Overall, piglet use of the creep increased with warm mat temperatures and brightness, which should be further investigated as potential strategies to promote piglet safety and reduce crushing in pen farrowing systems.     

Cortisol administration to pregnant sows affects novelty-induced locomotion, aggressive behaviour, and blunts gender differences in their offspring

Several behavioural effects of prenatal stress are reported in literature, and these seem to depend, among other factors, on the gender studied and the period of gestation in which prenatal stress is applied. In the present study, oral administration of hydrocortisone-acetate (HCA) to 41 pregnant sows was used as a model for prenatal stress, since corticosteroids are considered a key mediator in the effects of prenatal stress. HCA was orally administered to pregnant sows during three periods of gestation: 21-50 (period 1, P1, n = 10), 51-80 (period 2, P2, n = 10) and 81-110 (period 3, P3, n = 10) days after insemination (term 115 days). Control sows (n = 11) received vehicle from 21 to 110 days after insemination. Between days 9 and 48 after birth, treatment effects on male and female piglet behaviour were determined in the home pen and in four different behavioural tests. During the backtest, no gender differences were observed in vocalisations in HCA-piglets, while control males vocalised more than control females. In the home pen at 14 days of age, HCA-piglets spent less time in social interactions than control piglets. During the novel environment test, P1- and P3-piglets walked more than control piglets, but this was not observed during the novel object test, four days later. At weaning, P2- and P3-piglets performed less individual play. Prior to mixing with an unfamiliar piglet (male piglets only), HCA-piglets had lower salivary cortisol concentrations than control piglets, but no difference was observed after mixing. P1-, P2-, and P3- piglets had fewer non-aggressive encounters, and P2-piglets continued fighting longer than control piglets. The present study demonstrates that elevated maternal cortisol concentrations during gestation affect piglet behaviour, and effects do differ between male and female piglets. In addition, effects depend on the period of cortisol administration.     

The effects of modifying the farrowing environment on sow behaviour and survival and growth of piglets

The effect of modifying the farrowing environment on maternal behaviour of sows and survival and growth of piglets was studied. Sixteen sows farrowed in standard crates (CC) or in the same crates modified (MC) by addition of straw on the floor and a hessian cover over the farrowing stall. About 6 h after farrowing was completed, the environments were made similar by removing the hessian cover in the MC treatment and adding straw to the CC treatment. The MC sows performed more (P<0.05) nesting behaviour before farrowing, were more (P<0.05) responsive to the distress vocalizations of their piglets throughout lactation and tended to perform more (P<0.07) piglet-directed investigation/vocalization than CC sows. The incidence of piglet mortality was lower (P<0.01) in the MC than CC treatment. It was concluded that modifications to the farrowing environment can affect maternal behaviour, with apparent consequent advantages for piglet survival.     

Characteristics of American alligator bites on people in Florida

Human–American alligator (Alligator mississippiensis) conflict in Florida, USA, has increased since the early 1970s, along with the recovery of the American alligator population. To better understand factors contributing to the risk of people being bitten by free-ranging alligators in Florida, we evaluated the trend of alligator bites during 1971–2014 and examined characteristics associated with bites on people documented during 1948–2014. We classified 372 bites as either unprovoked or unintentionally provoked and used these in further analyses. Major injuries to victims occurred in 247 bite incidents. The estimated annual number of bites resulting in major injury to the victim increased from 3.5 to 7.0 during 1971–2014. The number of bites per Florida resident did not show a significant trend during 1971–2014. No significant change occurred in the frequency of fatal attacks during 1971–2014. Monthly frequency of bites was positively correlated with both mean maximum and mean minimum air temperatures but was not significantly correlated with testosterone concentration in adult male alligators, suggesting that bites are more likely related to feeding rates associated with seasonal fluctuations in ambient temperature than to aggression by male alligators during the breeding season. A high percentage of bites (41.8%) occurred in unnamed water bodies, which were generally small or man-made. Most (93.7%) victims were Florida residents, and 58.7% resided close to the incident site. Victims were predominantly male (81.4%), and adults were more frequently victims than were adolescents or children. Most victims (93.9%) were in the water or near the shore when bitten. Victims were more likely to sustain major injuries if the bite occurred in deeper water. Male alligators were more frequently (76.9%) responsible for bites. We found only 1 instance in which a bite was associated with defense of eggs or young by an adult female alligator. Evidence of people feeding alligators before the bite was documented in 34.7% of bite incidents. Twenty-two fatalities were attributed to alligator attacks, but we could not discern a pattern in the ages of victims. Alligators responsible for severe or fatal bites were predominantly in good condition with few deformities or injuries. Most alligator bites in Florida appeared to be attempts at feeding, although 36.8% of incidents entailed a single bite followed by immediate release, suggesting that alligators were unsure about their prey or were biting in defense. The risk of alligator bites can be reduced by educating people likely to interact with alligators and by selectively removing problem alligators in human residential areas and water bodies used regularly by people for swimming, wading, and shoreline activities. © 2019 The Wildlife Society.     

The effect of two teeth resection procedures on the welfare of piglets in farrowing crates. Part 1

Teeth resection is a method of controlling the injurious effects of the aggression displayed when newborn piglets fight to establish a teat order. Recent European legislation discourages the practice. The objective of this study was to assess the effect of clipping and grinding piglets’ needle teeth, compared to leaving them intact, on the welfare of piglets in farrowing crates.

Six days pre-partum, 60 sows were assigned to one of three treatments. Litters had their teeth clipped (C), ground (G) or left intact (I) at birth. The time taken to carry out each procedure was recorded. Piglet weights and facial lesions, which were scored according to severity, were recorded on days 1, 4, 11, 18 and 27. Piglet weights were also recorded at birth. Mouth lesions were recorded on days 1, 4 and 27. Instantaneous scan samples of piglet behaviour were carried out for 30 min post-teeth resection procedure (1 min intervals), and for 6 h on days 1, 4, 8, 14, 21 and 26 (5 min intervals). One male and one female piglet per litter were chosen as focal animals and observed for 5 min each post-procedure and for 10 min each twice per day on days 1, 5, 12, 20 and 26. Mortalities were recorded throughout lactation.

Grinding took significantly longer than clipping the teeth or leaving them intact (F = 638.87, P < 0.001). I piglets had higher facial lesion scores than C and G piglets (F = 10.58, P < 0.001). A smaller proportion of piglets in I litters than C and G litters and a smaller proportion of piglets in G litters than C litters had at least one mouth lesion (F = 4.74, P < 0.001). During 30 min post-procedure, I piglets were active on the heatpad in more observations than C and G piglets (F = 3.49, P < 0.05). During 5 min post-procedure C piglets spent longer chomping than I piglets (F = 5.92, P = 0.05). On day 21, I piglets were active in more observations than G piglets (F = 2.11, P < 0.05). On day 26, G piglets were inactive in more observations than C and I piglets (F = 5.02, P < 0.05). On days 14 and 26, C piglets were sleeping in more observations than G piglets (F = 2.87, P = 0.05). There was a tendency for a larger proportion of I than C piglets to die due to overlying (F = 2.68, P = 0.08).

In conclusion, although all three options were associated with welfare problems, grinding can be recommended in preference to clipping or leaving the teeth intact.     

Birth weight variation in the domestic pig: effects on offspring survival, weight gain and suckling behaviour

In domestic pigs, litter-mates often vary considerably in birth weight. To examine whether this size variation influences piglet survival, weight gain and suckling behaviour, we experimentally manipulated the number and size distribution of litter-mates in 51 litters. Litters were small (eight or nine piglets) or large (11 or 12 piglets) compared to the herd mean of 10 piglets, and were made more or less variable in weight by using the largest and smallest quartiles of two combined litters (variable) or the middle two quartiles (uniform). Weights were measured on days 0, 3 and 21. Behavioural measures (percent of nursings missed, mean teat consistency score, per capita number of teat disputes before milk ejection, and percent time spent in teat disputes in the 20min after milk ejection) were recorded on days 1, 4, 10 and 17. Piglet weight variation (percent of coefficient of variation, CV) almost doubled over the 21 days in uniform litters and actually decreased in variable litters, but still remained higher in the variable litters. Overall, survival, percent of nursings missed, consistency in piglets' use of teats, number of teat disputes, percent time a piglet spent in teat disputes after milk ejection, and weight gain were unaffected by birth weight variation although there was a tendency (P=0.09) for more piglet deaths in variable litters. Behavioural measures of sibling competition were higher in large litters. The data provide little support for the hypotheses that high birth weight variation results in decreased survival, or that it permits rapid establishment of dominance, thereby reducing wasteful competitive behaviour in surviving piglets.     

Jejunal morphology and blood metabolites in tail biting,victim and control pigs

Tail biting has several identified feeding-related risk factors. Tail biters are often said to be lighter and thinner than other pigs in the pen, possibly because of nutrition-related problems such as reduced feed intake or inability to use nutrients efficiently. This can lead to an increase in foraging behavior and tail biting. In this study, a total of 55 pigs of different ages were selected according to their tail-biting behavior (bouts/hour) and pen-feeding system to form eight experimental groups: tail-biting pigs (TB), victim pigs (V) and control pigs from a tail-biting pen (Ctb) and control pen (Cno) having either free access to feed with limited feeding space or meal feeding from a long trough. After euthanasia, a segment of jejunal cell wall was cut from 50 cm (S50) and 100 cm (S100) posterior to the bile duct. Villus height, crypt depth and villus : crypt ratio (V : C) were measured morphometrically. Blood serum concentration of minerals and plasma concentration of amino acids (AA) was determined. Villus height was greater in Cno than Ctb pigs in the proximal and mid-jejunum (P < 0.05), indicative of better ability to absorb nutrients, and increased with age in the proximal jejunum (P < 0.001). Serum mineral concentration of inorganic phosphate (P_i) and calcium (Ca) was lower in Ctb compared with Cno pigs, and that of P_i in V compared with all the other pigs. Many non-essential AA were lower in pigs from tail-biting pens, and particularly in victim pigs. Free access feeding with shared feeding space was associated with lower levels of essential AA in blood than meal feeding with simultaneous feeding space. Our data suggest that being a pig in a tail-biting pen is associated with decreased jejunal villus height and blood AA levels, possibly because of depressed absorption capacity, feeding behavior or environmental stress associated with tail biting. Victim pigs had lower concentrations of AA and P_i in plasma, possibly as a consequence of being bitten.     

Piglets' weaning behavioural response is influenced by quality of human-animal interactions during suckling

The aim of this study was to compare the short-term post-weaning behaviour of piglets treated either neutrally or aversively during the suckling period. A total of 24 lactating sows and their litters were housed in different rooms according to treatment. A female experimenter (P1) was in charge of feeding and cleaning from days 10 to 27 after birth. For the aversive treatment (Aver), P1 was noisy, moved harshly and unpredictably and shouted frequently during routine cleaning of facilities and animal handling. For the neutral treatment (Neut), P1 used a soft tone of voice and was careful during the same routine. At weaning, the avoidance response of piglets to an approaching experimenter in a novel place was assessed in four piglets from each litter. Scores ranged from 1 (experimenter could touch piglet) to 4 (piglet escaped as soon as person moved). The test was repeated twice, with a 1-h interval, with P1, who wore blue trousers and white T-shirt, and a second handler unfamiliar to the piglets (P2, who wore blue coveralls). Thereafter, litters from the same treatment were mixed and housed in separate rooms, balanced for gender and live weight (n = 12 groups of 4 piglets/treatment). Behaviour time budgets were registered by scan sampling every 2-min, for 4 h per day, for 4 days. Piglets were weighed at birth, at weaning and on day 5. Effects of treatment and handler on responses to the avoidance test were analysed with non-parametric tests and effects of treatment with a mixed model for repeated measures. Avoidance score was higher for Aver than Neut piglets when tested with P1 (P = 0.04) but not with P2 (P = 0.8). When piglets' responses to the different handlers were compared within each treatment, no significant differences were found. Frequencies of resting were lower (P < 0.001), whereas escape attempts (P < 0.03), agonistic interactions (P < 0.02) and frequency of presence at feeder (P < 0.001) were higher in the Aver than in the Neut groups. Feed and water intake and weight gain did not differ between treatments. We conclude that 4-week-old piglets can discriminate a handler according to the nature of treatment received during suckling. In addition, piglets treated aversively seem to have more difficulty adapting to weaning than those treated neutrally during the suckling period.     

Old breeds,new solutions? Effects of two different traditional sire breeds on skin lesions,tail lesions,tail losses,performance and behaviour of rearing pigs

Some studies indicated a relationship between modern, fast-growing, lean-meat-producing hybrid pigs and the occurrence of tail-biting, one of the major issues of conventional pig husbandry. Therefore, this study investigated the effects of different local, traditional sire breeds on the behaviour and performance of rearing pigs. Between December 2019 and November 2020, a total of 1 561 piglets were weaned from hybrid sows (Bundes Hybrid Zucht Programm (BHZP) Landrace × BHZP Large White) that were paired with either Swabian-Hall (SH), Bentheim Black Pied (BB) or BHZP-Piétrain (Pi) boars. Tails of the piglets were left intact (43.5%) or docked (56.5%), and male piglets were castrated. Piglets were conventionally reared on fully slatted plastic flooring in mixed-sex groups. Starting one day after weaning, skin lesions were scored once per pig, and tail lesions and losses were scored weekly until the end of rearing. The average daily gain was documented for the suckling and rearing period. The activity behaviour of eight focal pens was analysed using video recordings. Differences between modern and traditional breeds were found in this study for so-called aggressive and non-aggressive biting pronounced by skin and tail lesions and tail losses. Significantly fewer BB pigs had severe skin lesions on the front body than SH or Pi pigs (P < 0.05). Additionally, piglets that were classified as light (<5.6 kg) at weaning showed skin lesion scores of 0 more often than piglets that were classified with a medium (≥5.6–≤8.3 kg) or heavy (>8.3 kg) weaning weight (P < 0.05). In the first half of the rearing period, significantly more BB pigs were assessed as having no tail lesions and tail losses than SH and Pi pigs (P < 0.01). However, these differences disappeared in the second half of rearing. Either docked or undocked Pi pigs had significantly higher average daily gains than SH and BB pigs (P < 0.05). The activity of the focal pens was not influenced by the sire breed or tail lesion class, which might be due to the limited sample size of eight pens. To conclude, the use of the traditional sire breed BB has the potential to reduce injurious behaviour in the offspring. However, adjustments to the housing and feeding should be taken to further reduce the incidence of tail lesions and losses and to enhance performance.     

Colostrum production by sows: variability of colostrum yield and immunoglobulin G concentrations

Colostrum provides newborn piglets with energy, immunoglobulins and growth, thereby playing an essential role in piglet survival. However, colostrum yield and composition are highly variable among sows. Some of the factors involved in this variability have been identified. The aim of the study was to confirm previous findings on a large number of animals and to investigate other potential factors of variation, such as the process of farrowing and the morphological changes of the mammary epithelium that occur during the 24 h post partum. The experiment was conducted on 16 Large White (LW) and 56 Landrace (LR)×Large White (LR×LW) crossbred sows of mixed parities and their litters. Most farrowings were induced at 113 days of gestation and all farrowings were attended. Each piglet was weighed at birth and 24 h after farrowing started (t24). Colostrum ingestion by individual piglets was estimated using piglet weight gains from birth to t24. Colostrum production by sows was estimated by summing up colostrum intakes by each piglet of the litter. Colostrum was collected at the onset of farrowing (t0) and at t24 to determine concentrations of immunoglobulins G (IgG), Na and K. Analyses of correlations and multiple regressions were performed to identify the variables involved in variation of colostrum yield and IgG concentrations. Colostrum yield was not related to litter size and weight (P>0.1). It was negatively correlated with the number of stillborn piglets (r=-0.33, P=0.005) and within-litter variation of piglet birth weight (r=-0.24, P=0.04). It was not related to the Na/K ratio in the colostrum, which is an indicator of the integrity of the mammary epithelium. When sows were categorised according to their level of colostrum yield, sows that produced a low yield of colostrum had more stillborn piglets at birth than the other sows (P<0.05) and tended to have a longer birth interval during the early process of parturition (P<0.1). At t24, concentrations of IgG in the colostrum were positively correlated with the Na/K ratio in the colostrum (r=0.53, P<0.001), which indicates the concomitance of the cessation of IgG transfer to the colostrum and the changes in the morphology of the mammary epithelium. This study points out the need for future research on the role of the hormones involved in both the process of parturition and lactogenesis in the relationship between stillbirth, process of parturition and colostrum production.     

Health parameters in tail biters and bitten pigs in a case–control study

Health in relation to tail-biting behaviour was investigated on a problem farm. Quartets (n = 16) of age- and gender-matched fattening pigs including a tail biter (TB, n = 16), a victim (V, n = 16), a control in the same pen (C_tb, n = 10) and a control in a pen where no tail biting was observed (C_no, n = 14) were chosen by direct behavioural observation. Haematological and clinicochemical analyses, autopsy and histological examination of 16 different tissues were carried out. Tail lesion severity was evaluated both macroscopically, on the basis of inspection, and histologically, in the sagittally cut tail. Category effects were tested using Friedman's ANOVA by Ranks, Cochran's Q or a repeated-measure GLM and, if significant, pair-wise tests were conducted using Wilcoxon Signed Ranks or McNemar's Test. The number of received tail bites correlated better with histological than with macroscopic tail lesion scoring because of deep inflammation beneath healthy skin in some cases. Most individuals had mild inflammatory lesions in internal organs suggestive of generalized activation of the immune system, and 30% of the animals were anaemic, possibly because of systemic spread of infectious agents. V had more severe respiratory organ lesions and higher serum protein concentrations than all other categories of pigs. Liver- and muscle-specific enzymes (alanine aminotransferase, alkaline phosphatase and creatine kinase) differed between categories. In conclusion, most animals had signs of generalized activation of the immune system, possibly because of systemic spread of infectious agents. V pigs suffered from more severe inflammatory lesions than TB, C_tb or C_no. Deep infections may exist under healthy skin in the tail of bitten pigs.     

Temporary crate opening procedure affects immediate post-opening piglet mortality and sow behaviour

Producers are interested in utilising farrowing systems with reduced confinement to improve sow welfare. However, concerns of increased mortality may limit commercial uptake. Temporary confinement systems utilise a standard crate which is opened 3 to 7 dayspostpartum, providing protection for neonatal piglets at their most vulnerable age and later increased freedom of movement for sows. However, there is anecdotal evidence that piglet mortality increases immediately after the temporary crate is opened. The current study aims were to determine if piglet mortality increases post-opening, to trial different opening techniques to reduce post-opening piglet mortality and to identify how the different opening techniques influence sow behaviour. Three opening treatments were implemented across 416 sows: two involved opening crates individually within each farrowing house when each litter reached 7 days of age, in either the morning or afternoon (AM or PM), with a control of the standard method used on the farm to open all crates in each farrowing house simultaneously once the average litter age reached 7 days (ALL). Behavioural observations were performed on five sows from each treatment during the 6 h after crate opening, and during the same 6 h period on the previous and subsequent days. Across all treatments, piglet mortality was significantly higher in the post-opening than pre-opening period (P<0.0005). Between opening treatments, there were significant differences in piglet mortality during the 2 days after crate opening (P<0.05), whilst piglet mortality also tended to differ from crate opening until weaning (P=0.052), being highest in ALL and lowest in PM. Only sows in the PM treatment showed no increase in standing behaviour but did show an increased number of potentially dangerous posture changes after crate opening (P=0.01), which may be partly attributed to the temporal difference in observation periods. Sow behaviour only differed between AM and ALL on the day before crate opening, suggesting the AM treatment disrupted behaviour pre-opening. Sows in AM and PM treatments showed more sitting behaviour than ALL, and therefore may have been more alert. In conclusion, increases in piglet mortality after crate opening can be reduced by opening crates individually, more so in the afternoon. Sow habituation to disturbance before crate opening may have reduced post-opening piglet mortality, perhaps by reducing the difference in pre- and post-opening sow behaviour patterns.     

Early identification of neonates at risk: traits of newborn piglets with respect to survival

Despite technological changes and improved management, piglet mortality remains a problem for both production and welfare. Most preweaning mortality occurs within the first 3 days after birth because of problems with adaptation and development. Thus, the purpose of our study was to determine the physiologic state of newborn pigs with respect to piglet survival. Data were collected from 1024 live-born piglets of 106 primiparous German Landrace sows to analyze relationships between farrowing traits, early postnatal vitality and blood chemistry, including immunity of piglets at birth. Surviving piglets were compared with those that died during the first 10 days of life. The survivors were significantly heavier at birth (P=0.001), were born earlier in the birth order (P=0.04), reached the udder and took in first colostral milk more quickly (P=0.001) and had a smaller drop in rectal temperature I h after birth (P=0.001) than dead. However, dead piglets had significantly higher blood levels of inorganic phosphorus (P=0.0001), calcium (P=0.04) and urea (P=0.05), but a lower concentration of alpha2-macroglobulin and lower lymphocyte proliferation indices in response to pokeweed mitogen (P=0.05). Models fitted for discrimination between survivors and piglets that died included, in addition to birth weight and litter size, the foraging behavior of neonates (time from birth to first suckle) and their thermoregulatory capacity (rectal temperature 1 h after birth) in the first experimental unit, as well as prenursing biochemical measures (inorganic phosphorus, calcium and glucose) in the second experimental unit. These ethophysiological and biochemical traits of early postnatal vitality are important determinants of maturity and development at birth. Hence, breeding programs and perinatal housing and feeding conditions should ensure a high physiological maturity to improve mortality rates of neonates.     

Relationships between serum IGF-I concentrations and piglet development or neonatal viability following porcine somatotropin (pST) and insulin administration to gestating gilts

This study was designed to evaluate the effects of exogenous treatment with pST, insulin and their combination on periparturient serum IGF-I levels, prenatal piglet development and viability. Pregnant Yorkshire gilts were injected daily with either 5 ml of saline (C), n = 23; 5 mg pST (P), n = 23; 0.50 IU/kg of insulin (I), n = 23; or pST plus insulin at the above dosage, according to 2 x 2 factorial design from Day 30 to 70 of gestation. All gilts were sacrificed on Day 113 of gestation. Peripartum IGF-I serum levels were determined by RIA following a 36 h incubation in 0.2 M gly-gly HCL. Recovery of human rIGF-I standard was > 95%, while the intra-assay CV was 5.74%. Measures of piglet viability were compared using Randall's adaptation of Apgar score for human neonates. Piglet weight and crown-to-rump length were determined prior to dissection. Treatments (P, I and P + I) elicited highly significant increases in maternal serum IGF-I concentrations (321.9, 337.0, 375.0 vs 247.6 ng/ml; P = 0.0001) on Day 113 of gestation. Nonsignificant differences were detected in piglet serum IGF-I (94.8, 102.6, 110.2 vs 92.2 ng/ml; P = 0.06). These results revealed no relationship between piglet weight and maternal (r = 0.03) or piglet serum IGF-I levels (r = 0.08). Only a weak association between gilt and piglet serum IGF-I concentrations (r = 0.26) was detected. Injections with pST and or insulin did not influence piglet viability scores (P = 0.74). Viability scores were highly correlated with piglet weight (r = 0.66), crown -rump length (r = 0.70), but not with IGF-I concentrations in gilt (r = 0.09) and piglet serum (r = 0.16). Body weights, crown -rump length and visceral organ weights of piglets did not differ between control and hormone -treated gilts (P >/= 0.05). These results indicate 1) that there was no direct treatment effects on in utero piglet development or neonatal viability; 2) that IGF-I production in gilt and piglet compartment is independent, suggesting fetal endocrine autonomy regarding IGF-I production; and 3) that the usual low IGF-I concentrations in mid-late gestation in swine could be replenished by maternal pST and or insulin therapy.     

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.     

Development of eliminative behaviour in piglets

The development of eliminative behaviour in piglets was followed by watching piglets from the day of birth through to 5 weeks of age. Two different environments were used to establish the role of the sow. Six-day-old piglets consistently voided outside their lying area. The sow played no part in influencing where a piglet eliminated. Siblings also did not influence another piglet. When the lying area of the piglets was experimentally fouled, the lying behaviour of the piglets was disrupted. It was concluded that piglets dislike some property(s) of soiled bedding and so avoid soiling their lying area. The conclusion that piglets avoid eliminating in their lying area is contrasted with suggestions that piglets have a preferred elimination site.