Analysis of periparturient risk factors affecting sow longevity in breeding herds

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The association of periparturient risk factors with sow longevity and the validity of sow removal decisions made during the periparturient period were analyzed. Data pertaining to 2066 sows from a commercial breeding herd from the US Midwest were used in this study. The likelihood of removal from the herd within 35 d post-farrowing decreased with a younger parity, the absence of lameness or other health problems, a higher lactation feed intake (LFI) and a greater number of live-born piglets (P a younger parity lowered (P number of piglets born alive was higher (P periparturient period. A greater (P periparturient period farrowed. More sows (P culled compared with sows retained without health problems during the periparturient period. In summary, periparturient factors such as LFI, the incidence of lameness or health problems, as well as sow-level characteristics such as higher parity and fewer piglets born alive predicted the removal of a sow from the breeding herd. Sows retained with periparturient health problems had reduced longevity and fewer live-born piglets, and fewer such sows had another farrowing.

For more information the full article can be found at http://jas.fass.org/

A note on the effects of co-mingling piglet litters on pre-weaning growth, injuries and responses to behavioural tests

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Two coping styles, ‘‘active’’ and ‘‘passive’’, are well defined for some species (see Koolhaas et al., 1999 for a review). Even though the existence of distinct coping styles in pigs is controversial (Jensen et al., 1995), studies on coping abilities have provided insights into piglet behaviour (Hessing et al., 1993; Ruis et al., 2001). Behavioural tests have been used to identify possible behavioural patterns indicative of coping styles. Hessing et al. (1993) introduced the backtest as a general assessment of pigs’ coping styles. According to Benus et al. (1991) passive copers are less social, less aggressive and show longer attack latencies than active copers. Consequently, social challenges, in which piglets are allowed to interact with unfamiliar individuals (D’Eath and Burn, 2002) and social isolation tests (Ruis et al., 2001) have been used as indicators of pigs coping styles. In pigs, the effects of co-mingling litters on coping abilities before weaning are unclear. Thus, the purpose of this study was to determine how co-mingling litters affected piglets’ pre-weaning growth, ear injuries, suckling behaviour and responses to behavioural tests used to measure coping abilities. Thirty sows and their respective litters were housed in standard farrowing crates until day 13 after birth. On day13, the partition between two neighbouring pens was removed for 20 litters allowing piglets to interact (forming 10 co-mingled litters). The remaining 10 control litters were kept in standard farrowing crates throughout the experiment. Three focal piglets from each litter were used for data collection. Focal piglets were weighed and ear injuries recorded on days 2, 4, 9, 12, 15 and 18 after birth. There were no differences in piglets’ weight gain before or after co-mingling. Ear injuries were more abundant in co-mingled litters on day 15 (P < 0.05) but these differences disappeared by day 18. Suckling behaviour was recorded on days 5, 8, 10, 14, 16 and 18 after birth. There were no differences in teat fidelity, suckling frequency and mother fidelity between treatments. Three behavioural tests, social challenge, isolation, and backtest, were performed before and after co-mingling. There were no treatment effects on piglets’ response to the isolation test and backtest. Co-mingled piglets showed longer latency for the first aggressive interaction (P < 0.05), spent more time in proximity to one another (P < 0.05) and performed less single bites (P < 0.05) than control piglets during the social challenge. In addition, the duration and frequency of aggressive interactions (P < 0.05) were lower in co-mingled piglets than control piglets. Co-mingling did not affect the frequency of single head thrusts or oral–nasal contact, but did tend to increase the frequency of escape attempts (P < 0.10). Our results suggest that co-mingling litters during lactation affects piglets’ social behaviour, by primarily decreasing aggressive interactions during social challenges.

For more information the full article can be found at http://journals.elsevierhealth.com/periodicals/applan/issues

Effects of space allowance on the welfare of dry sows kept in dynamic groups and fed with an electronic sow feeder

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The minimal legal space allowance for grouped pregnant sows in the EU is 2.25 m2/sow. The effect of higher
space per animal on agonistic behaviour and social stress of animals living in dynamic groups is not known.
Two groups of 34 pregnant Belgian Landrace sows were housed in two pens of respectively 102 m2 (3 m2/
sow) and 76.5 m2 (2.25 m2/sow). Each sow lived there for 15 weeks. Sows were fed through an electronic sow
feeder. According to the dynamic system, one third of each group (i.e. 11 or 12 nearly parturient sows) was
replaced every 5 weeks by the same number of recently inseminated sows.Welfare indicators were collected
during six of these 5 week-periods: performance, agonistic behaviour, skin lesion score and salivary cortisol.
No differenceswere observed for production parameters, or for fighting activity. However, themean number of
one-way aggressions, when observed during 2 h-periods at 3 and 8 days after grouping, was significantly lower
in the large pen than in the small one (respectively 16 X 2 versus 26 X 3, p < 0.01, and 10 X 2 versus 20 X 5,
p < 0.05). The mean number of injuries was also lower with the 3 m2 space allowance, when collected on the
introduced sows one, 2 and 3 weeks after grouping. Some contradictory differences in salivary cortisol were
noted 2 and 26 h after mixing, but without reaching statistical significance. An available area 33% higher than
the EU legal minimum reduced agonistic behaviour and consecutive wounds and thus induced better welfare
conditions for sows living in dynamic groups and fed with an electronic sow feeder. The impact on productivity
and social physiological stress need further research.

For more information the full article can be found at http://journals.elsevierhealth.com/periodicals/applan/issues

Physiological and Productive Responses of Environmental Control on Housed Sows

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Since the 1960’s there have been significant changes in swine housing and management to improve production related to restrictions on animal movement, social interactions, thermal comfort, and welfare (Esmay, 1969; Pinheiro et al., 2002; Tolon, 2002). Current knowledge states that appropriate housing should meet the physiological needs of sows (Rapp et al., 1988; Turner et al., 1998; Bridges et al., 1998; Nääs, 2000). High temperatures affect swine performance, which can be evaluated by physiological response (Curtis, 1983; Perdomo, 1994; Banhazi et al., 2000). When subjected to heat stress sows tend to decrease productivity by reducing feed consumption; reduce reproductive efficiency (Love, 1978; Love, 1981); deliver less piglets (Domínguez, et. al., 1996), and present low performance of piglets at weaning (Mount, 1974; Quiniou & Noblet, 1999; Sousa, 2002; Tolon, 2002; Brown-Brandl & Eigenberg, 2000). Adult sows are more resistant to cold than to excessive heat exposure, benefiting from the use cooling acclimatization in housings (Curtis, 1983; Nääs, 2000; Barbari & Guerri,
2005). Environmental control alleviates heat stress improving productive responses (Müller, 1982; Bortolozzo et al., 1997; Hannas, 1999). Reduction of the heat load can be achieved by properly designed ventilation and cooling systems, in both gestating and nursing housing (Bull et al., 1997; Gates et al., 1991a). Room evaporative cooling and head ventilation systems help reducing the negative effects of high temperatures in farrowing rooms (Dong et al., 2001; Barbari & Guerri, 2005). Misting systems are lower in efficiency when compared to conventional pad systems (Roller & Goldman, 1969; Bottcher et al., 1991) but the equipment noise may cause animal agitation (Barbari & Guerri, 2005). Thermal index evaluation in swine confinement has been used to identify regions suitable for a particular housing design (Turner et al., 1998). This study evaluated the use of distinct environmental cooling equipments on sow performance, both on the gestation and on nursing in open sided housing. Two treatments were tested in the gestation building: natural ventilation and mechanical ventilation associated to fogging; while in the nursing rooms three treatments were tested: natural ventilation; mechanical ventilation; and evaporative cooling with forced ventilation. Sows were randomly chosen from the same genetic lot form six combined treatments. The evaporative cooling system in the farrowing room differed for piglet performances, at birth (4% higher) and on daily weight gain (15% higher), and also for sow physiological response improving the respiratory rate (8%) and back fat thickness (3%), without influencing skin temperature. The use of evaporative cooling directed to the sow head during nursing improved the physiological and productive results.

Net joint kinetics in the limbs of pigs walking on concrete floor in dry and contaminated conditions

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This study had the objective of analyzing the net joint movements and net joint reaction forces (Joint kinetics) in the forelimbs and hindlimbs of pigs walking of solid concrete floors. Also examined was the effect floor conditions had on the joint kinetics of the pigs. It was found that the forelimb joints of the pigs responded more to floor condition than the hindlimb joints, probably because the forelimbs carry more weight. In particular, between the dry and greasy floor conditions, the joint loading differed, most likely because the pigs adapted to a potentially slippery surface.

For more information the full article can be found at http://jas.fass.org/

Effect of surgical castration on the behavioural and acute phase responses of 5-day-old piglets

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The objective of this study was to assess the behavioural response to castration of male pigs; and evaluate its effects on levels of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-a) and interleukin-1beta (IL-1b), as well as cortisol; and the acute phase proteins C-reactive protein (CRP), serum amyloid A (SAA) and haptoglobin (Hp). It was found that Castrated piglets tended to have higher cortisol levels than handled pigs. Hence, behavioural observations were useful for evaluating the consequences of surgical castration on the welfare of pigs, indicating that animals undergoing this surgical procedure experience pain and discomfort that is persistent for up to 4 days.

For more information the full article can be found at http://journals.elsevierhealth.com/periodicals/applan/issues

Using movement sensors to detect the onset of farrowing

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Over the past few decades, in order to optimise sow fertility research in the field of animal reproduction has focused mainly on ovulation and pregnancy rates. During each farrowing, however, an average of one piglet is lost due to problems in the process of parturition, and an additional piglet is lost within a few days after birth (Edwards, 2002). Therefore, focusing research on farrowing is not only economically important but it can improve the health and welfare of the dam and her offspring. Problems during and shortly after parturition can seriously compromise animal health and can have an effect on the production economy of the pig farms. In modern pig herds, the lack of surveillance at farrowing is a current problem. Increased intensity of pig production has inevitably raised challenges during farrowing. Large litter sizes may result in delivery problems often associated with dystocia (Smith, 1997). Also, in large litters some of the piglets are more likely to be weaker and to require assistance soon after birth. Parturition should therefore be closely supervised in order to minimise losses due to problems with sows or piglets. Some studies have demonstrated that human supervision at farrowing can halve the piglet perinatal mortality (Holyoake et al., 1995; White et al., 1996). However, constant human supervision of all the farrowing sows has not been considered feasible, due to the high cost of labour and the working hours required. Currently, research is being carried out in the field of automatic growth control of pigs (Parsons et al., 2007). However, systems for automatically detecting farrowing do not exist today. Prediction of the onset of farrowing with a degree of accuracy could improve herd management and consequently improve the supervision of parturition. In sows, certain physiological and behavioural parameters are clear signals of impending parturition. Some of these parameters have been studied around farrowing, including the rise in body temperature (King et al., 1972; Elmore et al., 1979), the rise in respiratory rate (Hendrix et al., 1978) and behavioural changes (Hartsock and Barczewski, 1997; Bradshaw and Broom, 1999). All these changes occur 24–36h before farrowing starts. Thus, monitoring the variation in these parameters during the last days of pregnancy could likely serve to predict the onset of farrowing. One of the clearest signals of approaching farrowing is the increased activity due to nest building behaviour. Hartsock and Barczewski (1997) found that rooting, pawing, turning and walking behaviour in sows kept in pens or crates begins to increase 24h prior to farrowing. Therefore, the aim of our study was to test different movement sensors to measure changes in the farrowing-related activity of crated sows. These sensors could also be used to develop an automatic alarm system to help farmers to predict the onset of parturition. This would allow for more effective work organisation, reduce losses due to farrowing complications and weak piglets, and thus improve animal welfare. On the 764 farms included in the national litter-recording scheme in Finland, total piglet mortality averaged 22.4% (the mortality of liveborn piglets was 13.9%) in 2001 (Sternberg, 2002). For sows, 2768 treatment cases for farrowing problems on 942 farms included in the health recording scheme were recorded that same year (Rautala, 2002). Moreover, 15.4% of all veterinary treatments in the herds participating in the scheme were due to post partum dysgalactia syndrome (PPDS).

For more information the full article can be found at  http://www.sciencedirect.com/science/journal/15375110

A meta-analysis on experimental infections with porcine circovirus type 2 (PCV2)

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A meta-analysis was performed with the aim to identify factors with a relevant influence on the expression of clinical
postweaning multisystemic wasting syndrome (PMWS) under experimental conditions. It was found the most successful animal experiment aimed to develop PMWS should include: (1) colostrum-deprived pigs, (2) age of inoculation below 3 weeks, (3) high doses of PCV2 inoculum, (4) PCV2 strain from genotype 1, and (5) co-infection with another swine pathogen as a triggering factor.

For more information the full article can be found at http://www.sciencedirect.com/science/journal/03781135

Visual acuity of pigs at different light intensities

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In most West European countries pigs are housed indoors under low-light conditions. While former
Dutch National legislation for pigs required 12 lx for 8 h per day, EU legislation requires 40 lx, so pigs
should be able to distinguish small objects and subtle visual signals. However, limited scientific evidence
exists about the effects of light intensity (illumination) and object size on the pigs’ ability to distinguish
visual cues. We studied these two effects using operant conditioning with a Landolt-C symbol as shape
discriminator. Four Landolt-C symbols with different sizes (with gaps of, respectively, 10 mm(L10), 20 mm
(L20), 30 mm (L30) and 40 mm (L40)) were tested under 8 different illuminant levels (0.5, 3, 6, 12, 20, 30,
40 and 80 lx). Following a 4-week training period, 20 female 4-month-old pigs were tested in two batches
and the numbers of correct, hesitant and incorrect choices were recorded. Reduced illumination significantly
increased the number of incorrect choices (P < 0.05). Symbol size also had a significant effect (P < 0.001);
pigs made more mistakes with the two smaller symbols L10 (41.5%) and L20 (28.6%) compared to the
bigger symbols L30 (17.3%) and L40 (16.3%). Furthermore, pigs hesitated less with the smallest symbol
L10 (4.5%) compared to L20, L30 and L40 (17.3, 22.3 and 23.0%, respectively; P < 0.001). Visual acuity
(ability to distinguish details and shapes) varied from 0.001 to 0.03 and pigs failed to discriminate visual
cues below 20 mm. Results indicate that the detail of the visual cue (symbol size) has a more pronounced
effect on the pigs’ ability to distinguish visual cues, compared to the illuminant level.

For more information the full article can be found at http://journals.elsevierhealth.com/periodicals/applan/issues

Novelty causes elevated heart rate and immune changes in pigs exposed to handling, alleys, and ramps

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Economic losses related to the handling of pigs are well known throughout the industry (Tarrant, 1989). Handling effects on pig stress are complicated and few studies have quantified stress responses in common handling situations. In times of stress, the HPA (hypothalamic pituitaryadrena axis) axis is activated and glucocorticoids are released into the blood of the pig. Stress also causes changes in measures of the immune system (McGlone et al., 1993; Morrow-Tesch et al., 1994; Hicks et al., 1998; Salak-Johnson and McGlone, 2007). Alongside endocrine and immune responses to stress, stressed animals may undergo physiological changes such as increased heart and respiration rates that lead to an increase in body core temperature. Heart rate can be determined by use of telemetry to obtain undisturbed responses within experimental groups (Von Borell, 2001; Von Borell et al., 2007; Marchant-Forde et al., 2003a,b). The main hypothesis for this study was that when pigs are exposed to a novel environment they would have a higher heart rate and an overall stress response compared with those pigs that were habitualized with the environment. We also sought to determine if minimal training to remove novelty would reduce the stress experience for pigs destined for transport to slaughter. The ultimate goal is to reduce or eliminate stress-induced problems with pig losses during transportation and handling. Ten test subject pigs were selected per treatment. The first (trained) group was trained to navigate a course including a ramp. Testing was daily for seven days. Once training was completed, the trained and control (naïve) groups were exposed to a fixed course, the course and ramp (both up and down) while heart rates, time, handling difficulty, and blood were collected to determine the innate responses. It was concluded that heart rates of trained pigs were reduced significantly compared to naïve pigs travelling the same course. Both handling ease and handling time were significantly improved for the trained pigs compared to naïve pigs. Blood immune measures indicated reduced stress among trained pigs that had lower neutrophil numbers and lower total and average phagocytosis compared with naïve pigs. This study demonstrated that the exposure of pigs to a novel environment clearly causes a mild physiological response. Alleys and ramps do not inherently stress pigs, but rather novel experiences cause handling problems and a stress response and minimal training can reduce the stress experience for the pig.

For more information the full article can be found at http://www.journals.elsevierhealth.com/periodicals/livsci