Iso-antibodies to red cell antigens in pigs' sera 3. The effect of maternal red cell iso-antibodies on the red cells of piglets

The effect of the red cell antibody, anti-Ea, on the red cells of piglets in four litters was studied. Although the antibody was absorbed from the colostrum by all the piglets, it had little effect on their packed cell volume, haemoglobin and red cell counts, and no differences were noted between Ea-positive and Ea-negative piglets in the same litter, despite the fact that red cells of the former were positive for the direct Coomb's test for up to a week after birth.
Anti-Ea was not detected in the serum of Ea-positive piglets, all of it apparently being taken up by their red cells, unlike the Ea-negative ones, in whose serum anti-Ea could be detected for up to fifteen weeks of age.     

Iso-antibodies to red cell antigens in pigs' sera. 2. The incidence of iso-antibodies to red cell antigens in the sera of adult pigs

On examining the sera from 80 sows and 67 boars in the routine typing service carried out by the Blood Group Research Unit, no antibodies other than anti-A were found in the boars' sera while, in 26% of the sows' sera, other anti-red-cell antibodies were also found as well as anti-A. All these sows were bred to boars of the same breed as themselves. The sera of 50% of 24 sows which had produced litters affected with thrombocytopenic purpura and which were mainly bred to boars of different breeds than themselves also contained iso-antibodies.
Of these iso-antibodies, anti-Ea and anti-Eb were the most frequent and were also present at the highest titres. Anti-Ee, anti-Fa, anti-Ka, anti-Kb, anti-Kd, anti-La and anti-Lg were also found but usually at only low titres.     

Lack of stimulation of relaxin secretion in lactating sows by suckling in vivo or by oxytocin in vitro.

After parturition, eight sows were zero weaned by removing all piglets 6 h after birth; a further 18 sows suckled at least ten piglets each. Blood samples were collected on Day 4 after zero weaning or on Days 4, 14 and 21 of lactation and the sampling frequency increased during suckling bouts. Ovaries were recovered from sows on these days and corpora lutea were either extracted for estimation of relaxin and progesterone concentration, fixed for immunohistochemical analysis or incubated in vitro in the presence or absence of luteinizing hormone (LH) or oxytocin. Luteal weight and progesterone were higher in the zero-weaned sows than in lactating sows (P less than 0.05 and less than 0.001, respectively); relaxin content was below detection by Day 14. This was supported by immunohistochemical staining for relaxin, which showed limited immunostaining in zero-weaned and Day 4 sows, but none in the tissue recovered on Days 14 and 21, which showed typical signs of regression. Secretion of progesterone and relaxin by luteal tissue in vitro was highest in zero-weaned sows (P less than 0.05), decreased as lactation progressed and neither LH nor oxytocin had any significant effect. Concentrations of plasma relaxin were all less than 0.2 ng/ml in three of the four zero-weaned and Day-4-suckled sows assayed; there was no detectable increase during suckling bouts. It was concluded that during lactation the old corpus luteum of pregnancy is not able to release relaxin in response to suckling in vivo or to oxytocin treatment in vitro.     

The transmission of campylobacter in piggeries; an epidemiological study

The campylobacter infection of 10 sows and their piglets was monitored. These pigs werekept on two multiplier farms. Rectal faeces samples were taken from the sows shortly beforelittering and at different intervals after littering. Swab samples of rectal content were taken fromsix piglets per sow at different intervals after birth. Nine sows were shown to be infected withcampylobacter before litter and all sows after litter, with an average colony count of 4·1in log N g^–1 of faeces. Half of the piglets became infected withcampylobacter during the first week of life and 85%, after four weeks. Two genetic subtypingmethods (ERIC-PCR and RFLP) were used to study the relationships between campylobacterisolates from sows and piglets. A large diversity of campylobacter subtypes was found.Nevertheless, piglets and their mothers often harboured campylobacter isolates with identicalgenetic subtyping profiles, suggesting that piglets become infected via their mothers. However,observed similarities in genetic subtyping profiles between campylobacters isolated on differentfarms made this difficult to prove.     

Supplying sows energy on the expected day of farrowing improves farrowing kinetics and newborn piglet performance in the first 24 h after birth

The farrowing process is one of the most energy-demanding activities for the modern hyperprolific sow. This study evaluated the effects of supply of energy on the expected date of farrowing on the farrowing kinetics and piglets’ performance during the first 24 h after birth. A total of 80 sows were used. The sows and their respective litters were considered as the experimental unit. On the expected day of farrowing, the sows were allocated to one of the following groups: sows that did not have access to feed from farrowing induction until the end of the farrowing process (CON, n = 40); sows fed 500 g of energetic supplement, which consisted of 250 g of the basal lactation diet plus 250 g of cane sugar, 18 h after farrowing induction (SUP, n = 40). The farrowing duration, farrowing assistance, birth interval, number of total born, stillborn and mummified piglets were recorded for each sow. Piglets were weighed individually at birth and 24 h later. The interval from birth to first suckle was evaluated individually for each piglet in 16 randomly selected litters (eight litters per treatment group). Blood glucose concentrations of six sows were measured shortly after expulsion of the first piglet. Farrowing duration, farrowing assistance and stillborn rate tended to be greater (P = 0.06, P = 0.09 and P = 0.07, respectively) in sows from the CON group compared to sows from the SUP group. However, there was no difference (P > 0.05) between the groups for birth interval. Colostrum intake was greater (P < 0.05) for piglets from the SUP group compared to piglets from the CON group. Additionally, BW gain of the piglets suckling the SUP group was greater (P < 0.05) than those suckling the CON group at 24 h after birth. The blood glucose concentrations during the expulsive stage of farrowing were greater (P < 0.05) in the SUP group than for sows from the CON group. In conclusion, supplying modern hyperprolific sows energy on the expected day of farrowing is a valuable nutritional intervention to improve the farrowing kinetics and piglets’ performance in early life.     

Passive immunization against transmissible gastroenteritis virus in piglets by ingestion of milk of sows inoculated with attenuated virus.

Pregnant sows were inoculated with the attenuated strain, TO--163, of swine transmissible gastroenteritis virus. Suckling piglets born from them received challenge inoculation with the virulent virus at 3 days after birth, and examined for ability to prevent infection and the immunoglobulin (Ig) classes of antibody in milk. A pregnant sow was inoculated intramuscularly with a dose of 10(8.0) TCID50 and intranasally with a dose of 10(9.3) TCID50 of attenuated virus. Piglets born from it suffered from diarrhea after challenge inoculation, but none of them died eventually. Their dam was also affected with diarrhea for 4 to 7 days after challenge inoculation of them. Another pregnant sow was inoculated twice with 10(9.3) TCID50 of attenuated virus, first by the intramuscular and secondly by the intranasal route. Of nine piglets born from it, one excreted soft feces after challenge inoculation, but all survived to grow normally. Their dam manifested no clinical symptoms at all after challenge inoculation of them. The higher the titer of virus inoculated into pregnant sows, the higher the neutralizing antibody titer in serum and milk of the sows after farrowing. The puerperal sow which had received two doses of 10(9.3) TCID50 each of attenuated virus by the intramuscular and intranasal route, respectively, presented the highest neutralizing antibody titer of all the inoculated sows. This titer was 2,048 in serum and 14,183 in colostrum immediately after farrowing. In that sow IgG was the main class of immunoglobulins in neutralizing antibody in milk. Even the IgA antibody titer of that sow was higher than that of any other sow which had been administered with virus of low titer. It was 392 and 19 3 and 9 days, respectively, after farrowing.     

Field trials on transmissible gastroenteritis live virus vaccine in newborn piglets.

Field trials were conducted on attenuated live virus vaccine of transmissible gastroenteritis to confer active immunity to newborn piglets. To examine innocuity and efficacy of the vaccine, a total of 714 newborn piglets were subjected to these trials. Of them, 357 piglets were administered orally with 10(7.0) TCID50 within 3 days after birth, and the other 357 piglets served as nonvaccinated controls. No undesirable postvaccinal reaction was observed in any vaccinated piglet. Suckling piglets born from nonimmune sows showed a good antibody response after vaccination. They were different, however, in antibody titer from one experimental place to another. Antibody levels were high in piglets raised in the northern experimental places. On the contrary, the antibody response of suckling piglets born from immune sows was influenced by vaccination. In most of these piglets, antibody titers declined markedly and disappeared finally 3 months after vaccination. About 25% of the non-vaccinated piglets showed an antibody response by pen contact with vaccinated ones.     

Modifications in the aggressive and ingestive behavior of the neonatal piglet as a result of prenatal elevation of cortisol in the dam

Ninety-eight piglets from 10 sows were used to study their neonatal agonistic and ingestive behavior after stimulation of the preparturient sow with adrenocorticotrophic hormone (ACTH). The sows were randomly assigned to either an ACTH or a control group on the 104th day of gestation. Sows in the ACTH group were catheterized and infused with 1IU porcine ACTH kg⁻¹ day⁻¹ in 1 l of saline. Control sows were similarly catheterized and infused with the same volume of saline, both treatments being maintained until parturition. A blood sample was collected daily from all sows. At birth piglets were weighed, bled and freed in the rear of the farrowing crate. They were then observed for the first 6 h of life to record their birth to suckle (BTS) interval. At the same time all instigator and victim interactions were recorded. Three subsequent blood samples were then collected from the piglets at 2, 4 and 6 h of life, and analyzed for glucose and cortisol. In both groups the concentration of plasma cortisol proved to be decreased (P<0.05) after birth while glucose increased within 2 h. The total number of instigations observed was higher (P<0.05) in pigs born to control sows than in those born to ACTH-treated sows. When values were expressed as instigations per pig or number of instigations relative to the total number of possible interactions within the litter, piglets of the ACTH group also exhibited less (P<0.05) aggressive instigations than those born to the control sows. Victimizations were not influenced either by treatment or sex. ACTH pigs had slightly shorter BTS intervals (P<0.05) than those in the control group. Females were lighter (P<0.05) than males at birth but they took less time to suckle than males. Accordingly it is concluded that the prenatal treatment of the sows with ACTH reduces the rate of agonistic interactions and tends to reduce the time required for first-time successful suckling.     

Sows exposed to octylphenol in early gestation: No estrogenic effects in male piglets, but increased rate of stillbirth

Octylphenol is an industrial chemical with estrogenic effects both in vitro and in vivo. In this study the effects of short-term intramuscular exposure to 0.1 mg/kg of body weight and 1.0 mg/kg of body weight in early gestation were evaluated in pregnant sows with respect to reproductive parameters in the newborn male piglets, as compared with male piglets from unexposed control sows. The male piglets were examined immediately after birth with respect to the macroscopic appearance of the reproductive organs and testosterone concentration in serum. It was not possible to identify any estrogenic effects in the newborn male piglets. However, in the sows exposed at the highest level of octylphenol, there was an increased number of stillborn piglets and an increased proportion of sows with stillborn piglets in the litter (P < 0.05). This was an unexpected finding which has not been reported previously.     

Body weight loss during lactation and its influence on weaning-to-service interval and ovulation rate in Landrace and Yorkshire sows in the tropical environment of Thailand

The aim of this study was to investigate the ovulation rate and the weaning-to-service interval (WSI) of sows in relation to their body weight loss during lactation in tropical climatic conditions. Effect of lactation length (LL), number of total born piglets, number of live born piglets, litter birth weight, average piglet birth weight, number of pigs weaned, litter weaning weight and average pig weaned weight on sow weight loss during lactation were also studied. This study was conducted in two commercial purebred sow herds (A, B) in the central part of Thailand from August to December 1997. The herds had both Landrace (L) and Yorkshire (Y) sows. The 123 sows (55 L and 68 Y) in herd A and 153 sows (95 L and 58 Y) in herd B, parity 1-4, were weighed within 4 days after farrowing and at weaning. Lactation length, litter size at birth and at weaning, litter weight at birth and at weaning, and WSI were recorded for each of these sows. In herd A, 52 sows (20 L and 32 Y) were examined once by laparoscopy between days 8 and 14 after AI-service. These sows had farrowed at least seven piglets in the previous parturition. The numbers of corpora lutea (CL) in both ovaries were counted, and were assumed to equal the ovulation rate. L-sows had significantly (P < 0.05) higher relative weight loss during lactation (RWL) than Y-sows. The RWL increased by 0.7% for each extra pig weaned. When LL increased by 1 day, within the interval of 17-34 days, RWL decreased by 0.6%. Sows with a high weight loss had significantly (P < 0.05) longer WSI than sows with medium or low weight loss. Weight loss had a significant (P < 0.05) effect on WSI in parity 1 and 2 sows. Y-sows had more CL than L-sows (15.7 versus 14.0) (P < 0.05). RWL, parity and regression on lactation length had no significant effect on number of CL. In conclusion, sows with higher number of pigs weaned lose more weight. Under the restricted feeding regime applied, high weight loss during lactation prolongs WSI in parity 1 and 2 sows, but has no influence on the ovulation rate at first oestrus after weaning. The ovulation rate is higher in Yorkshire than in Landrace sows. The ovulation rate is independent of parity.     

Response of performance characteristics and fecal consistency to long-lasting dietary supplementation with the probiotic strain Bacillus cereus var. toyoi to sows and piglets

As part of an interdisciplinary research project, we studied the performance response of sows and their litters to the probiotic strain Bacillus cereus var. toyoi as well as feces consistency of piglets. Gestating sows (n=26) were randomly allotted into two groups. The probiotic B. cereus var. toyoi was administered by dietary supplementation to one group of sows and their respective litters (probiotic group) whereas the second group (control group) received no probiotic supplementation. The duration of the application was nearly 17 weeks for sows (day 90 ante partum until day 28 post partum) and six weeks for piglets (day 15-56). Piglets were weaned after 28 days. Body weight and feed consumption were recorded weekly and fecal consistency of weaned piglets was studied daily. B. cereus var. toyoi was recovered from feces of sows and piglets as well as from digesta of piglets in the probiotic group, while being absent from all samples of control animals. In addition, the probiotic was detected in piglet feces and digesta before pre-starter feed was offered, indicating a second route of uptake besides diet. Sows of the probiotic group nursed numerically more piglets and supported a higher sum of total nursing days of all piglets within each litter than control sows (p = 0.04). In turn, body weight (BW) up to day 35 was greater for control piglets (p < 0.01), while average daily gain and gain to feed ratio (G:F) in weeks six and eight postweaning was higher in the probiotic group (p < 0.05). The overall G:F of the total postweaning period was 680 g/kg and 628 g/kg in the probiotic group and control group, respectively (p = 0.009). During the trial a high prevalence of liquid feces with its maximum in the second week after weaning was observed. Probiotic supplementation led to a reduction in the incidence of liquid feces and postweaning diarrhea by 38% and 59%, respectively (p < 0.001).     

Effect of radiant heat at the birth site in farrowing crates on hypothermia and behaviour in neonatal piglets

It has been documented that floor heating of the farrowing area in loose housed sows improves survival of piglets significantly. However, today, the majority of farrowing pens are designed with crating of sows and slatted floor at the birth site. The aim of this study was to investigate whether providing radiant heat at the birth site to new-born piglets in pens with crated sows reduced hypothermia, time to first milk intake and growth of the piglets during the 1^st week. Second parity Danish Landrace×Yorkshire sows (n=36) were randomly divided into two groups: Control (CG) and heat (HG). In the area behind the sow (zone 1), two radiant heat panels were mounted above the slatted floor in the HG. The farrowings were attended, and the heaters were turned on at birth of first piglet and turned off 12 h after. Birth time, time to leave zone 1, time to first contact with udder and time to first suckling were registered by direct observation. The piglet’s rectal temperature (RT) was measured 15, 30, 60, 120, 180, 240 min after birth and 12, 14 and 24 h after birth of first piglet. Piglets were weighed at birth, 24 and 48 h and 7 days after birth. Data were analysed in a mixed model in SAS. The drop in RT was lower in HG compared with CG (P=0.002), and the RT in HG remained higher than in CG from 30 to 240 min after birth (P<0.05), whereas no difference was found at 12 h after birth of first piglet (P=0.92). Piglets in HG stayed longer in zone 1 than those in CG (P=0.01), whereas time to reach udder (P=0.35) and to first suckling (P=0.56) did not differ. No difference in weight gain was found between piglets in HG and CG at 24 h (P=0.23), 48 h (P=0.28) and 7 days after birth (P=0.44). Birth weight had a positive effect on RT (P<0.001) and reduced time to leave zone 1 (P<0.01), reach udder (P<0.001) and time to first suckling (P<0.001). The results showed that radiant heating behind the sows reduced hypothermia in new-born piglets and indicate that providing heat during the first half hour after birth is important.     

A behavioural scale to measure ease of farrowing in sows

Farrowing is one of the most critical phases in pig production, as it has an impact on neonatal pig survival. Assessing the ease of farrowing can improve the management of sows and thus increase litter survival. The aims of this study were: 1) to develop an ease of farrowing score (EFS) in sows based on the behaviour of the sows and their piglets, and 2) to determine the relationship between the EFS and productive, physiological, and subjective parameters. Eighty hybrid (Large White × Landrace) sows from first to seventh parity housed in individual crates were used. An EFS was constructed using the total duration of farrowing, the birth interval, the total time standing or sitting, the number of position changes during the day before and the day of farrowing, the sow posture at birth, the viability and the position of the piglets at birth (head or back born). Moreover, rectal temperature at 90 min after farrowing, a four categorical subjective visual assessment (VA) of farrowing and litter size (piglets born alive, stillborn and mummified foetus) were recorded. A common factor analysis model yielded five factors with an eigenvalue higher than 0.95 that accounted for 75.05% of the total variation between individuals. The three main factors were “farrowing duration”, “sow posture”, and “sow activity” of sows and explained 23.44%, 15.67%, and 14.23% of the variance, respectively. Primiparous sows had higher values for factor 3 (sow activity) than multiparous sows (P = 0.02). Sows without stillborn or mummification foetus showed higher values of EFS than sows with at least one stillborn or mummification foetus (P = 0.06 and 0.01, respectively). Sows that received a visual assessment of 3 and 4 showed higher values of EFS than sows that received a VA of 1 and 2 (P = 0.0017). The EFS appears to be a good behavioural scale to measure ease of farrowing in sows kept in individual farrowing crates. Duration of farrowing, sow position, and presence of stillborn piglets and mummified foetuses appear to be important ease of farrowing indicators.     

Farrowing rates and litter size following transfer of vitrified porcine embryos into a commercial swine herd

The objective was to determine farrowing rates and litter sizes that could be achieved in a typical farm-to-farm porcine embryo transfer program using vitrified blastocysts that were zona pellucida intact when cryopreserved. The embryos were transferred surgically on-farm into recipient sows that were managed throughout gestation and farrowing under the same conditions as other sows in the herd. Twenty recipient sows (mean parity 2.1) received a total of 568 embryos; seven received 203 embryos derived from donor sows, five received 139 embryos from gilts and eight received a mixture of 161 embryos from sows and 65 from gilts. Sixteen sows (80%) were confirmed pregnant at approximately 35 days gestation, 15 farrowed at full term (farrowing rate 75%). One sow died during gestation (with a total of 18 fetuses in utero). A total of 123 piglets were born (mean, 8.2), of which 115 were born alive (mean, 7.7). Of the 568 embryos transferred to all 20 sows, 21.6% resulted in piglets born and 29.0% survived to produce piglets in sows that farrowed. There were no significant differences in embryo survival among sow, gilt or mixed sow and gilt embryos. The ratio of males to females was 71/52 and the mean birth weight was 1.6 kg (range 0.6-2.6 kg). In conclusion, vitrified zona pellucida intact embryos can be used to transfer genetic material from farm-to-farm with acceptable reproductive performance.     

Genetic parameters for haemoglobin levels in sows and piglets as well as sow reproductive performance and piglet survival

Genetic parameters were estimated for haemoglobin (Hb) levels in sows and piglets as well as sow reproductive performance and piglet survival. Reproductive traits were available between 2005 and 2014 for 7857 litters from 1029 Large White and 858 Landrace sows. In 2012 and 2013, Hb levels, sow BW and sow back fat depth were measured on 348 sows with 529 litters 5 days prior to farrowing. In addition, Hb levels were available for 1127 one-day-old piglets from 383 litters (a maximum of three piglets per litter) of 277 sows with Hb levels. The average Hb levels in sows (sow Hb), their litters (litter Hb, based on average Hb of three piglets) and individual piglets (piglet Hb) were 112 ± 12.6 g/l, 103 ± 15.3 g/l and 105 ± 21.7 g/l, respectively. Heritabilities for Hb levels were 0.09 ± 0.07 for sow Hb, 0.19 ± 0.11 for litter Hb and 0.08 ± 0.05 for piglet Hb. Estimates for the permanent environment effect of sows were 0.09 ± 0.09 for sow Hb, 0.11 ± 0.12 for litter Hb and 0.12 ± 0.03 for piglet Hb. In comparison, heritabilities for both number of stillborn piglets and pre-weaning survival were lower (0.05 ± 0.01 and 0.04 ± 0.01). Sow BW had no significant heritability, while sow back fat depth was lowly heritable (0.10 ± 0.08). Positive genetic correlations were found between sow Hb and litter Hb (0.64 ± 0.47) and between litter Hb and sow back fat depth (0.71 ± 0.53). Higher litter Hb was genetically associated with lower number of stillborn piglets (−0.78 ± 0.35) and higher pre-weaning survival (0.28 ± 0.33). Negative genetic correlations between sow Hb and average piglet birth weight of the litter (−0.60 ± 0.34) and between piglet Hb and birth weight of individual piglets (−0.37 ± 0.32) indicate that selection for heavier piglets may reduce Hb levels in sows and piglets. Similarly, selection for larger litter size will reduce average piglet birth weight (r_g: −0.40 ± 0.12) and pre-weaning survival (−0.57 ± 0.13) and may lead to lower litter Hb (−0.48 ± 0.27). This study shows promising first results for the use of Hb levels as a selection criterion in pig breeding programs, and selection for higher Hb levels may improve piglet survival and limit further reduction in Hb levels in sows and piglets due to selection for larger and heavier litters.     

Maternal dietary supplementation with ferrous N-carbamylglycinate chelate affects sow reproductive performance and iron status of neonatal piglets

Iron-deficiency anemia is a public health concern that frequently occurs in pregnant mammals and neonatal offspring. Ferrous N-carbamylglycinate chelate (Fe-CGly) is a newly designed iron fortifier with proven effects in iron-deficient rats and weanling piglets. However, the effects of this new compound on pregnant mammals are unknown. Therefore, this experiment was conducted to evaluate the effects of Fe-CGly on sow reproductive performance and iron status of both sows and neonatal piglets. A total of 40 large-white sows after second parity were randomly assigned to two groups (n=20). They were receiving a diet including 80 mg Fe/kg as FeSO₄ or Fe-CGly, respectively, from day 85 of gestation to parturition. The serum (day 110 of pregnancy) and placentas of sows were sampled. Litter size, mean weight of live born piglets, birth (live) litter weight, number of live born piglets, and the number of still-born piglets, mummies, and weak-born piglets were recorded. Once delivered, eight litters were randomly selected from the 20 litters per treatment, and one new-born male piglet (1.503±0.142 kg) from each selected litter was slaughtered within 3 h after birth from the selected litters, without colostrum ingestion. The serum, longissimus muscle, liver and kidneys of the piglets were collected. The iron status of the serum samples and the messenger RNA level of iron-related genes in the placenta, liver and kidney were analyzed. The results showed that litter weight of live born piglets was higher (P=0.030) in the Fe-CGly group (19.86 kg) than in the FeSO₄ group (17.34 kg). Fe-CGly significantly increased placental iron concentration (P<0.05) of sows. It also significantly increased iron saturation and reduced the total iron-binding capacity of piglets (P<0.05) at birth. However, the results revealed that supplementation of Fe-CGly in sows reduced liver and kidney iron concentration of neonatal piglets (P<0.05), indicating decreased iron storage. In addition, the concentration of iron in the colostrum was not significantly changed. Therefore, the present results suggested that replacement of maternal FeSO₄ supplement with Fe-CGly in the late-gestating period for sows could improve litter birth weight, probably via enhanced iron transportation in the placenta.     

Genetic aspects regarding piglet losses and the maternal behaviour of sows. Part 2. Genetic relationship between maternal behaviour in sows and piglet mortality

The aim of the study was to analyse the genetic background of different traits to characterise the maternal behaviour of sows and to evaluate the relationship to different causes of piglet losses - increasing piglet survival due to higher maternal abilities of the sow. A total of 1538 purebred litters from 943 German Landrace sows in the year 2004 were available for data analysis. Around 13 971 individually earmarked piglets were included in the analyses. Maternal abilities were characterised through the sow's reaction to the separation from her litter during the first 24 h after farrowing, and on day 21 of lactation, the reaction towards the playback of a piglet's distress call and the reaction towards an unknown noise (music). In 1220 of these litters, the sows were also scored for aggressiveness in the group when regrouped before entering the farrowing crates. To describe fertility, the number of piglets born alive, stillborn piglets, number of piglets born in total and the individual birth weight were utilised. Different causes of piglet losses were evaluated as binary traits of the dam with survival rate, different definitions for crushing by the sow, being underweight and runts. The heritability for being aggressive in the group was h2 = 0.32 and for the behaviour traits during lactation, the heritabilities ranged from h2 = 0.06 to 0.14. The genetic correlations showed that more-reactive sows had fewer piglet losses.     

Effects of meloxicam (Metacam®) on post-farrowing sow behaviour and piglet performance

Farrowing is an intrinsically risky process for both the sow and the piglets that can cause welfare and economic problems. The effects of the non-steroidal anti-inflammatory drug meloxicam on post-farrowing behaviour of sows, and the performance of piglets were investigated. A total of 48 sows were randomly allocated at the day of farrowing (day 0) into two homogeneous groups regarding parity, and treated with either meloxicam or saline solution as placebo. For each sow, number of position changes, total time lying and standing or sitting, feed intake and rectal temperature (RT) were recorded during 3 days after farrowing. Piglets were individually weighed at farrowing and at weaning. The number of position changes did not show significant differences between treatments (P = 0.79). Sows spent significantly less time lying during day +3 after farrowing in the meloxicam group than in the placebo group (P = 0.04). Feed intake and RT showed a parity effect (P < 0.001 in both cases); however, no treatment effect was observed (P = 0.67 and P = 0.47, respectively). Pre-weaning mortality rate in piglets was not affected by treatment. In litters from multiparous sows, piglets of low birth weight (defined as percentile 15: BW <1180 g) had an average daily gain significantly higher in the meloxicam group than in the placebo group (196.6 ± 7.2 v. 166.6 ± 9.1 g/day; P = 0.03). Although the administration of meloxicam 90 min after farrowing showed a positive effect on the total time lying of the sows, additional investigations are required to better qualify relevant indicators of pain following farrowing in sows and to specify the analgesic effects of meloxicam on piglet performance.     

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.