Effects of sow-crate design on health and performance of sows and piglets

The effects of sow-crate design on certain health and performance traits of 211 sows and their piglets were evaluated with a 2 X 2 X 4 factorial arrangement of crate width (narrow [N = 55 cm] or wide [W = 64] between lowest horizontal pipes), length (short [S = 183 cm] or long [L = 198] from rump stop to front gate) and side type (lower side of sow crate "fingered" [F], "bowed" bottom bar--marking the sow zone 19.3 cm wider at the bottom--20 cm above the floor [B], or straight bottom bar 20 cm [S20] or 25 cm above the floor [S25]). Between d 107 to 110 postcoitum and d 21 postpartum, no crate design variable affected the sow's body-weight change, but side type tended to affect the most prominent head-neck and leg integumentary lesions. Number of stillborn piglets/litter was greater with W crates than with N, except with crates having S20 sides, and was greater with L crates than with S. More piglets were crushed to death in W crates than N crates, and stillbirth frequency was greater in L crates than in S, but overall preweaning piglet mortality was affected by no crate-design feature. At both 7 and 21 d of age, piglets' knee lesions were most severe with S20 crates and least with S25, whereas face-lesion score was unaffected by crate design. Piglet body weight at age 21 d was least with S20 crates and greatest with F and S25. No crate-design variable affected within-litter variation in piglet growth rate. Sow-crate design affected important health and performance traits of piglets through postnatal d 21.     

Lowering of the incidence of puerperal mastitis in the sow by protection of the mammae from contamination

Twelve sows each farrowed in an experimental pen designed especially for this study or in a crate. Viable counts of enterobacteriaceae were performed in samples taken from the laying area and from the teats. Secretion from every mammary complex was examined repeatedly for bacteria and for somatic cells. The sows in the experimental pen did not lay down in their own faeces. The viable counts in samples from the laying area and the teats were much lower than with the sows kept in farrowing crates. Infection with E. coli was observed in 3 mammary complexes of the sows in the experimental pen as compared to 27 complexes of the sows in the crate. More than half of the infections was detected in the samples taken before farrowing began. In the average the bacteria persisted for 1.3 days. On the first 4 days of life piglets sucking teats with cytologically defined mastitis had an average daily gain of 105 g as compared to 125 g with piglets sucking healthy teats. In conclusion puerperal mastitis is a consequence of faecal contamination of the mammary gland. Soiling of the laying area with faeces and urine can be reduced by improvements in the farrowing accommodations.     

An exploratory study on the effects of a straw dispenser in farrowing crates

The effect of a straw dispenser in farrowing crates was investigated to determine the extent to which the provision of small quantities of straw has an influence on both sows and piglets. Sows and suckling piglets are often housed in barren environments with limited opportunities to show behavior they are highly motivated to perform. Enriching the environment might be a solution; for example, by providing materials that can be manipulated. In this study, 20 sows received a straw dispenser with chopped straw (treatment group) and 20 other sows did not receive any enrichment (control group). The treatment group was split up in 2: in treatment group A, the straw dispenser was placed in front of the sow, above the feed trough; and in treatment group B, the straw dispenser was placed next to the sow. Sows from the treatment groups received the straw dispenser from arrival in the farrowing crate until weaning. The total straw use within the treatment group was very variable but did not differ before and after farrowing. Sows took on average 53.0 g (±8.85) straw from the straw dispenser during the whole period in the farrowing crate. The frequency of undesirable and stereotypical behavior performed by the sows did not differ between treatment and control groups, and the same is seen with nest-building behavior before farrowing. By positioning the dispenser in front of the sow, the frequency of lateral lying increased, which means the udder was exposed more toward the piglets. This was reflected in the higher frequency of udder activity, performed by piglets from this treatment group. By positioning the dispenser next to the sow, sows showed more ventral lying behavior, because of disturbance of lying behavior by piglets. Piglets from this treatment group also showed less udder activity and possibly because of this, more pain-related behavior. These piglets performed more playing behavior in the third week of life compared with other groups, but it cannot be stated with certainty that this is a positive effect. A lower weight gain and weaning weight were seen in piglets within treatment group B. Possible explanations are the higher level of activity among these piglets as the straw dispenser was positioned within their reach or decreased milk consumption because of decreased udder activity and increased ventral lying by the sows. It can be concluded that the straw dispenser has positive effects on the behavior and welfare of sows and piglets, but positioning the straw dispenser in reach of both sow and piglets is not preferred as it is associated with undesirable effects on behavior such as ventral lying in sows and pain-related behaviors in piglets.     

The association between sow and piglet behavior

Sows in modern pig industry are often housed individually in farrowing crates a few days before farrowing until weaning. These farrowing crates limit movements of the sow and therefore also limit them in expressing their behavior. These limitations may lead to distress with the sow and can result in stereotypical behaviors. Because it is possible that the general behavior of the mother sow also influences her piglets, the hypothesis of the present study was that there is an association between the general behavior of sows and the behavior of their piglets. Our results showed that there was indeed an association between the postures and activities of sows and the behavior of their piglets, not only for nursing–suckling behavior. Results also indicated that piglets prefer resting when sows are resting. When sows were standing up, piglets were running around more. Although there were indications that piglets were more at ease when sows were bar biting compared with when they were sham chewing, a specific relationship between sow stereotypical behavior and piglet behavior could not be demonstrated in the present study. Though, it should be taken in mind that relatively low frequencies of stereotypical behaviors were observed. Furthermore, it could be that not only the prevalence of a specific stereotypical behavior is important but also a specific threshold of that specific behavior should be exceeded to induce effects on the suckling piglets. Alternatively piglets could coinduce stereotypical behavior of the mother sow.     

Impacts of a freedom farrowing pen design on sow behaviours and performance

The limited space in farrowing crate imposes many challenges, such as prolonged farrowing duration and high piglet stillbirth rate. Although the features of farrowing pens compensate for the drawbacks of farrowing crates, they are associated with high piglet crushing mortality caused by the greater space afforded to sows and their rolling-over behaviour. Therefore, a freedom farrowing pen was designed to overcome the drawbacks of both farrowing crates and farrowing pens. The main features of the freedom farrowing pen are its left anti-crushing bar and detachable right anti-crushing bar on the sides of the sow lying area. It also has a 10 cm-high anti-crushing bar in the non-lying area. Eighteen healthy, multiparous Yorkshire sows (3-7 parity) were averaged and randomly assigned to farrowing crates, farrowing pens, and freedom farrowing pens to compare the effects of the farrowing systems on sow behaviour and performance. Results showed that the farrowing duration and the mean piglet birth intervals were longer for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P<0.05), but there was no difference between the sows in farrowing pens and those in freedom farrowing pens (P>0.05). The piglet stillbirth rate was higher for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P<0.001). Crushing mortality was higher among piglets in farrowing pens (P<0.001), but there was no difference between piglets in freedom farrowing pens and those in farrowing crates (P>0.05). The freedom farrowing pen and the farrowing pen allowed sows to turn around and move freely, but because of the different structures of their anti-crushing bars, the increase in sow movement did not cause higher piglet crushing mortality (P>0.05). Sows in freedom farrowing pens were found to be more protective of their piglets.     

Evaluation of methods of providing supplemental heat to newborn pigs during and after farrowing.

Two experiments were conducted to evaluate systems of providing supplemental heat to newborn pigs during and after farrowing. In Exp. 1, 35 sows were randomly allotted to farrowing crates with two supplemental heat treatments: 1) two lateral 250-watt heat lamps; and 2) two lateral heat lamps, plus a 250-watt heat lamp behind the sow during farrowing. In Exp. 2, 72 sows were randomly assigned to farrowing crates with four supplemental heat treatments: 1) one lateral 250-watt heater; 2) one lateral heater plus a 250-watt heater behind the sow during farrowing; 3) a hover with 100-watt light bulb; and 4) a hover with light bulb plus heater behind the sow during farrowing. The average farrowing house temperature was 18.9 degrees C in Exp. 1 and 21.6 degrees C in Exp. 2. Results showed no significant treatment effects on preweaning pig survival or growth rates in either experiment. Thus, providing a heat lamp at the rear of the sow during parturition was not beneficial and would increase operating costs. Hovers have a higher initial cost than conventional heat lamps or heaters, but they would have a much lower operating cost. Hovers may offer swine producers a way of reducing energy costs without affecting preweaning pig survival and performance.     

A cohort study of preweaning piglet mortality and farrowing accommodation on 112 commercial pig farms in England

A cohort study was carried out on 112 breeding pig farms in England to investigate the impact of type of farrowing accommodation on preweaning mortality in piglets. Four types of farrowing accommodation were studied; farrowing crates, indoor loose pens, crate/loose systems (where the sow was restrained in a crate during birth and the first days of lactation before being moved to a loose pen) and outdoor farrowing in arcs in paddocks. Four estimates of preweaning mortality were collected: an oral estimate from the farmer before the visit, an estimate from the 6-month rolling average from computer records, records from 20 litters observed when the farm was visited and prospective records collected from 20 farrowings after the visit. These four estimates were significantly correlated. The prospective records also included a farmer reported date and cause of death. From the prospective data there were 25,031 piglets from 2143 litters from 112 farms, 6.5% of piglets were stillborn while live born preweaning mortality was 12%. Mixed effect discrete time survival, binomial and competing risk, models were used to investigate the association between preweaning mortality and farrowing accommodation, controlling for sow parity, litter size and number of piglets stillborn and fostered. There was a reduced risk of stillbirths in outdoor farrowing systems compared with crated systems. Farmers reported that crushing of healthy piglets was the most frequent cause of death accounting for 55% of live born preweaning mortality. There was no significant difference in mortality in live born piglets by farrowing system. There was a significantly higher risk of farmer reported crushing of healthy live born piglets in outdoor arcs compared with piglets reared with sows in farrowing crates and a significantly reduced risk of death from causes other than crushing in piglets reared outdoors or in crate/loose systems compared with piglets reared in crated systems. We conclude that, in the farms in this study, farrowing crates reduced the risk of preweaning live born mortality attributable to crushing but piglets in this system were at increased risk of death from other causes. Consequently crates had no significant effect on overall preweaning mortality percentage. In all four commercial production systems; outdoor, farrowing crates, crate/loose farrowing systems and indoor loose housed systems, there were similar levels of mortality.     

Evaluation of drop versus trickle-feeding systems for crated or group-penned gestating sows

A total of 160 gilts were used to evaluate the effects of pen vs. crated housing systems and drop- vs. trickle-fed feeding systems on sow productivity, occurrence of lesions during farrowing and weaning, immune measures, and behavioral responses during 2 consecutive gestation periods. Of the 160 eligible gilts, 117 farrowed in parity 1, and of those, 72 farrowed in parity 2. The gilts were randomly assigned to represent 1 of 4 factorially arranged treatment groups: pen drop-fed, crate drop-fed, pen trickle-fed, or crate trickle-fed. Replicate blocks were used for each parity with 5 sows per block initially in each treatment. At weaning, sows housed in pens had greater (P < 0.05) backfat thickness than sows housed in crates. The piglet weaning weight was greater (P < 0.05) for sows fed with the single drop compared with the trickle-feeding system. Lesions scores and all other productivity measures did not differ among treatments. An interaction was observed for percentage of neutrophil phagocytosis (P < 0.05) between penning and feeding systems. In pens, drop-fed sows had greater phagocytosis than trickle-fed sows, but in crates, drop-fed sows had a tendency for lower phagocytosis than trickle-fed sows. All other immune measures were not different among treatments. The occurrence of oral-nasal-facial (ONF) behaviors (chewing, rooting, and rubbing) and active behaviors increased, and lying behavior decreased (P < 0.05), from 0800 to 1200 for all sows. During the 0800 to 1200 period, crate drop-fed sows displayed more (P < 0.05) ONF and active behaviors than did sows in the 3 other treatments. Sows housed in groups of 5 had a greater (P < 0.05) duration of standing in the 0400 to 0800 period compared with crated sows. Housing systems had complex effects on sow behavioral sequences, but penned sows had more sequences associated with stress than did crated sows. Also, crate drop-fed gilts and sows expressed more ONF behaviors than gilts and sows in other treatments. Generally, productivity, skin lesions, and immune measures were not different, but behaviors at certain times of day and behavioral sequences were different for sows in pens and crates with drop or trickle-feeding systems. None of the environments evaluated were associated with significant physiological stress responses among the sows. Thus, sows were able to adapt within each environment through behavioral mechanisms without the need to invoke major physiological adjustments.     

Between-breed variability of stillbirth and its relationship with sow and piglet characteristics

Litter characteristics at birth were recorded in 4 genetic types of sows with differing maternal abilities. Eighty-two litters from F(1) Duroc x Large White sows, 651 litters from Large White sows, 63 litters from Meishan sows, and 173 litters from Laconie sows were considered. Statistical models included random effects of sow, litter, or both; fixed effects of sow genetic type, parity, birth assistance, and piglet sex, as well as gestation length, farrowing duration, piglet birth weight, and litter size as linear covariates. The quadratic components of the last 2 factors were also considered. For statistical analyses, GLM were first considered, assuming a binomial distribution of stillbirth. Hierarchical models were also fitted to the data to take into account correlations among piglets from the same litter. Model selection was performed based on deviance and deviance information criterion. Finally, standard and robust generalized estimating equations (GEE) procedures were applied to quantify the importance of each effect on a piglet's probability of stillbirth. The 5 most important factors involved were, in decreasing order (contribution of each effect to variance reduction): difference between piglet birth weight and the litter mean (2.36%), individual birth weight (2.25%), piglet sex (1.01%), farrowing duration (0.99%), and sow genetic type (0.94%). Probability of stillbirth was greater for lighter piglets, for male piglets, and for piglets from small or very large litters. Probability of stillbirth increased with sow parity number and with farrowing duration. Piglets born from Meishan sows had a lower risk of stillbirth (P < 0.0001) and were little affected by the sources of variation mentioned above compared with the 3 other sow genetic types. Standard and robust GEE approaches gave similar results despite some disequilibrium in the data set structure highlighted with the robust GEE approach.     

Exposure to maternal feces in lactation influences piglet enteric microbiota,growth, and survival preweaning

It is known that gilt progeny performance is reduced compared with sow progeny. Previous research suggests that the presence of maternal feces in early life improves the health and survival of offspring. Therefore, we aimed to determine whether contact with feces from multiparous (MP) sows would improve the growth and survival of piglets born and reared on primiparous (P1) sows and if so, whether these differences are associated with the gut microbiota. Four treatments were applied for 10 days: Donor (n = 29) piglets had limited access to maternal feces as, each morning, sow feces were removed and placed in the crate of a P1 sow (P1-FT; n = 30 piglets) and P1-Con (n = 29) and MP-Con (n = 33) piglets had access to their own mothers’ feces. All piglets were weighed on days 1, 3, 10, and 18. Fecal samples were collected from a subset of sows (n = 10/treatment) 3 days post farrow and from two female piglets/litter on days 10 and 18 (n = 20/treatment) and subject to 16S rRNA amplicon analysis. Escherichia, Clostridium, Campylobacter, and Treponema were more abundant in MP sows, while P1 sows had a higher abundance of Lactobacillus and Prevotella. At 10 days, P1 progeny fecal microbiota differed, and growth and survival were reduced when compared with MP progeny. No treatment effect was observed for P1-FT piglets (P > 0.05). Donor piglets had a different fecal microbiota and improved weight and survival then all other treatments (P < 0.05). Overall, the removal of sow feces from the farrowing crate improved piglet microbiota development, growth, and survival.     

Elimination of strains of Streptococcus suis serotype 2 from the tonsils of carrier sows by combined medication and vaccination

The effect of vaccination with a killed whole-cell vaccine of extracellular factor-positive Streptococcus suis serotype 2 (S suis 2 EF(+)) combined with medication with amoxicillin on the presence of virulent S suis 2 EF(+) strains on the tonsils of sows and their offspring was evaluated. In two herds, 14 pregnant sows that carried these virulent strains, as detected by PCR in three consecutive tonsillar brush samples, were selected and randomly assigned to be treated or left untreated as controls. The treated sows were vaccinated at six and three weeks before the expected farrowing date and medicated from one week before expected farrowing until the end of the experiment. Two weeks before parturition, the sows were housed in individual isolation farrowing rooms, and the sow and its litter were sampled by using tonsil brushes and tonsil swabs, respectively. Approximately 27 days postpartum, the sows and their piglets were euthanased and their tonsils were collected and analysed by pcr. No S suis 2 EF(+) could be detected in the tonsils of the seven treated sows, but the tonsils of the seven untreated sows remained positive. Only one of the litters of the untreated sows became infected, five days after birth, and none of the litters of the treated sows became infected.     

Acquisition of Clostridium difficile by piglets

Clostridium difficile is recognized as an important cause of nosocomial diarrhoea in humans especially in association with administration of antibiotics. In pigs, C. difficile can cause neonatal enteritis and can be isolated from faeces from both diseased and healthy animals. The presented prospective study describes how soon C. difficile can be isolated from newborn piglets after normal parturition and how C. difficile spreads within a pig farm. Six sows, their farrowing crates and their litters at one farm were sampled until C. difficile was found in all piglets. Within 48 h after birth, all 71 piglets became positive for C. difficile (two piglets were already positive within 1h post partum), all sows became positive within 113 h after parturition and the farrowing crates were found intermittently positive. C. difficile could also be detected in air samples and in samples of teats of the sows. All isolates belonged to PCR ribotype 078. Twenty-one C. difficile ribotype 078 isolates, found at the farm, were further analyzed by MLVA (multiple-locus variable-number tandem repeat analysis) and belonged to one clonal complex, except one isolate. To be sure that piglets were not born already infected with C. difficile ribotype 078, 38 caesarean derived piglets were sampled immediately after surgery. All piglets tested negative at delivery and stayed negative for C. difficile ribotype 078 during the 21 days in which they were kept in sterile incubators. This study shows that C. difficile ribotype 078 spreads easily between sows, piglets and the environment. Vertical transmission of C. difficile ribotype 078 was not found and is very unlikely to occur.     

Socializing piglets before weaning: effects on behavior of lactating sows, pre- and postweaning behavior, and performance of piglets

This study evaluated how socializing piglets before weaning affects behavior of lactating sows and the pre- and postweaning behavior and performance of piglets. Two farrowing rooms, each with 6 pens, and 1 nursery with 4 pens were used. In total, data were obtained from 24 sows and their litters. In each farrowing room, the solid barriers between 3 farrowing pens were removed on d 12 after farrowing, and the sows remained confined in their crates (experimental group). In the other 3 farrowing pens of each farrowing room, sows and their litters were kept under conventional conditions until weaning (control group). All piglets were weaned 28 d after birth. After weaning, piglets from each group remained together in 1 pen of the nursery. The behavior of sows (lying, standing, sitting, nursing) and piglets (lying, active, suckling) in the farrowing rooms was observed for 24 h before and for 48 h after removal of the barriers between the pens. In addition, behavior (active, lying, feeding, agonistic behavior) of piglets was observed in the nursery during the initial 48-h period after weaning. Each piglet was weighed on d 5, 12, and 28 after birth and thereafter weekly until the fifth week of rearing. In the farrowing room, mixing of litters did not influence behavior of piglets and sows. Preweaning weight gain of the piglets did not differ (P = 0.60) between the treatments. In the initial 48 h after weaning, less agonistic behavior (P < 0.001) was observed in piglets belonging to the experimental group. During 5 wk of rearing, piglets in the experimental group gained more weight compared with the control group (P = 0.05). The advantage shown by the experimental group became especially conspicuous in the first week after weaning (P = 0.05). By socializing unfamiliar piglets before weaning, stress due to mixing could at least be distanced in time from the other burdens of weaning, thereby improving performance.     

Floor heating at farrowing in pens for loose-housed sows

The effects of floor heating at parturition on sow and piglet behaviour in pens were examined in a Danish production herd. A total of 50 gilts and sows were split into two groups; one (n = 25) experienced no treatment; one (n = 25) was exposed to floor heating in the area of the sow around parturition. The sows and piglets were recorded on video 24 h a day for behavioural analyses.Floor heating tended to improve piglet weight at weaning (P = 0.05) but did not affect average daily gain. Piglets in pens with floor heating were more often in proximity of the sow at posture changes than piglets from pens without floor heating on day one postpartum (P = 0.01). Floor heating did not affect duration of parturition or any of the recordings of sow behaviour significantly.     

The evaluation of secretion volume and immunoglobulin A and G concentrations in sow colostrum from anterior to posterior teats

Among domestic animals, teat order is only observed in the pig. In order to achieve the healthy growth and weaning of piglets, it is important to elucidate if volume of colostrum secretion and immunoglobulin A (IgA) and IgG concentrations differ among the teats of a sow. Nine sows were used to evaluate the difference in colostrum secretion volume (CSV) and four of these sows were assessed for IgA and IgG concentrations from each teat. Samples were collected five times during 21 h following parturition. Teats were assigned anatomical locations of teat (1 to 7) from anterior to posterior. The CSV of anterior (locations 1 and 2) and middle teats (locations 3–5) was significantly higher than those of posterior teats (locations 6 and 7) throughout the experiment except for 18 h post‐parturition (P < 0.05). The CSV of the teats at location 1 was significantly higher at most collection times than those at locations 6 and 7. A positive correlation of CSV was observed with IgA and IgG concentrations from 12 h and 6 h post‐parturition, respectively (P < 0.05). The results suggest that anterior teats secrete greater volumes of colostrum and that these tend to contain higher IgA and IgG than posteriors teats.     

The use of different vaccination schedules for sows to protect piglets against Aujeszky's disease

Several Aujeszky's disease virus (ADV) vaccination protocols of sows were evaluated with regard to the passive protection conferred on piglets in a recently built commercial farm. Three different groups of sows were vaccinated using a Bartha K-61 strain. One group received an inactivated vaccine during pregnancy and the other two groups received attenuated vaccines, either during pregnancy (day 65) or on the seventh day of lactation. At farrowing, sows vaccinated during lactation had lower seroneutralization titres than those vaccinated during pregnancy either with inactivated or attenuated vaccines. Accordingly, their piglets were the ones with lower levels of maternally transferred neutralizing antibodies. At 4 weeks of age, five piglets born of each group of sows were challenged intranasally with a neurotropic strain of ADV. Piglets born of sows vaccinated during pregnancy with inactivated and attenuated vaccines gained 1.50 kg bodyweight and 2.50 kg bodyweight during 7 days, respectively, and did not show clinical signs, while piglets from sows vaccinated during the previous lactation lost 0.60 kg and presented moderate to severe clinical signs of ADV. Vaccination of sows during pregnancy provided more protection against ADV for piglets than sow vaccination before mating. Piglets born from sows vaccinated with attenuated or inactivated vaccines did not present remarkable differences on protection.     

Fender design and insulation of farrowing huts: effects on performance of outdoor sows and piglets

Two studies assessed sow and litter performance when design features of farrowing huts varied. A fender is a structure that extends out the front of the hut to create a veranda that prevents young piglets from leaving. In Exp. 1, 206 lactating sows and their litters were used to assess litter performance and the time required to process litters for two fender designs (short wooden [WS] vs. tall metal with a board front [MT-b]) and insulation status (insulated [IN] vs. uninsulated [UN]) farrowing huts. A significant fender x insulation interaction was observed for total litter weaning weight. Lighter litters weaned (P = 0.013) from WS fenders with UN huts compared with the other treatments. Fender design did not (P > 0.05) influence the time required to process a litter with one stockperson. Less total time (P = 0.001) was required to process a litter when two people were present (10.60 +/- 0.74 min) compared with one stockperson (14.52 +/- 0.74 min). There were no (P > 0.05) differences between IN and UN huts for temperature and relative humidity measurements. In Exp. 2, 331 lactating sows and their litters were used to determine sow and litter performance when using one of two fender front designs (boards [MT-b] vs. roller [MT-r]). The front design of the fender did not influence (P > 0.05) most litter performance measures. We conclude that fender design, fender fronts, and insulation effects did not have large influences on sow and litter performance in a West Texas environment.     

Effects of Group Size during Pregnancy and Introduction Method on Behaviour of Relevance for Piglet Performance in Multi-suckling Pens

The effects of group size during pregnancy (12 or 24 sows) and introduction methods on behaviour in multi-suckling pens were studied. The introduction methods were: A) (control) all sows and piglets were moved simultaneously to the multi-suckling pen on day 11 after farrowing; B) sows and piglets were moved simultaneously on day 14 after farrowing; C) sows were moved simultaneously and, two hours later, all piglets were moved simultaneously on day 11 after farrowing; D) each sow and her litter were moved separately at three-hours intervals on day 11 after farrowing. The effects of group size during pregnancy interacted with the effects of introduction method. When housed in groups of 12 during pregnancy, treatments B-D resulted in more initiated, but fewer successful nursings compared to A. However, when sows had been housed in groups of 24 during pregnancy, increased age (B) resulted in a decreased number of initiated nursings compared to A, but an increased nursing synchrony. The results indicate that it is possible to affect behaviour in multi-suckling pens through the social environment during pregnancy and by the choice of introduction method.     

Farrowing induction induces transient alterations in prolactin concentrations and colostrum composition in primiparous sows

Hormonal changes involved in the farrowing process partly control the initiation of lactation. Inducing farrowing by injection of PG may alter the normal prepartum hormonal cascade. The aim of the study was to investigate the consequences of farrowing induction on colostrum yield and composition, as well as newborn piglet growth. Gilts were treated with 2 mg of alfaprostol on d 113 of gestation (induced farrowing, IF, n = 9) or were injected with 1 mL of a saline solution (natural farrowing, NF, n = 11). Colostrum production was estimated during 24 h, starting at the onset of parturition, based on piglet BW gains. Colostrum samples were collected during the 36 h after the onset of parturition. Blood samples were collected from sows as of d 112 of pregnancy until d 2 postpartum (d 0 being the day of parturition). Piglet blood samples were obtained at birth, on d 1, and on d 21. Litter size and litter weight at birth did not differ between groups (P > 0.10). Farrowing induction did not influence (P > 0.10) colostrum yield (3.96 ± 0.20 kg) or piglet BW gain during d 1 postpartum (116 ± 8 g). At the onset of farrowing (T0), lactose content in colostrum was greater in IF sows than in NF sows (P < 0.05), whereas colostrum ash and protein contents were less (P < 0.05) in IF sows. Concentrations of IgG in colostrum were similar in both groups of sows, whereas concentrations of IgA at T0 were less in IF than in NF sows (P < 0.01). Overall, endocrine changes in blood from d -2 until d 2 (cortisol, prolactin, progesterone, and estradiol-17β) were not altered by farrowing induction (P > 0.10), but 1 h after the injection of alfaprostol, IF sows had greater circulating concentrations of prolactin (P < 0.01) and cortisol (P < 0.10) than NF sows. The greater concentration of lactose in colostrum from IF sows could be attributed to this transient increase in prolactin and cortisol. At birth, concentrations of white blood cells were less in piglets born from IF sows (P < 0.01). On d 1 and 21, piglets from IF sows had similar IgG concentrations in plasma to piglets from NF sows (P > 0.1). In conclusion, farrowing induction at 113 d of pregnancy induced transient hormonal changes in sows and alterations in colostrum composition, without significantly affecting colostrum yield. It also modified some hematological variables of piglets at birth.     

Milk Production in Sows after Spontaneous Delivery and after Delivery Induced by PGF2α Analogs

In this study the amount of milk produced during the first week of lactation was compared in sows with induced parturition and sows which delivered spontaneously (with special attention to sows showing MMA symptoms). Fifteen sows (L X LW) were used from a pig farm in which MMA was seen in 20 to 25% of all farrowings. The animals were divided into three groups of 5 each. Group A and B were treated with two different PGF ₂ α analogs (2 mg of alfaprostol or 0.45 mg of tiaprost) on 111 day of pregnancy, and group C (control) with 2 ml of saline solution. Treatment with PGF analogs induced parturitions 24 to 30 h later, controls delivered spontaneously on day 114. Litters were equalized to nine piglets per sow. The milk yield of each sow was calculate using the method of weighing piglets before and after each suckling. Piglets were allowed to suckle 12 times in the first 24 h after parturition, then 8 or 9 times in the next 24 h and from 48 h onwards 8 times during 24 h, until the end of the 7 day observation period. During the first day after parturition the control group appeared to produce slightly more milk than groups A and B whereas from 24 to 48 h, milk yields decreased in all animals. From 48 onwards milk production increased in all groups. Between 72–96 h, two sows of the control group showed symptoms of MMA and their piglets developed diarrhea. Microbiological analysis confirmed the presence of haemolytic Streptococci. The lactation curves of treated and untreated sows with no signs of MMA were very similar; the pattern was more erratic in sows with MMA. The total milk yields during the first week of lactation did not differ between groups; there were no significative difference in the weight gain of the piglets in groups A, B and C. The difference recorded in milk yield and release patterns between sows with or without MMA opens new aspects with regard to the aetiology of a syndrome that not only involves the sows health, but produces intestinals disease in their piglets.