The effects of low levels of dietary trace minerals on the plasma levels, faecal excretion, health and performance of pigs in a hot African climate.

The present study was performed in order to evaluate the effects of lower than usual industry levels of dietary trace minerals on plasma levels, faecal excretion, performance, mortality and morbidity in growing-finishing pigs in a hot African climate. Group 1 (n = 100 pigs) received a diet with common industry levels of trace minerals. Group 2 (n = 100 pigs) received reduced dietary trace mineral levels but were fed the same basic diet as Group 1. Mortality, morbidity, pig performance and carcass measurements were evaluated. Two pigs in Group 1 and three pigs in Group 2 died. Thirteen pigs in Group 1 and 27 pigs in Group 2 were medically treated (P < 0.05). Carcass masses, back fat depth, loin depth, and lean percent were not significantly different between the groups. However, the carcasses when evaluated revealed a non-significant higher back fat thickness, lower loin eye area and percentage of fat-free lean in barrows compared to gilts within each group. Despite lower initial masses, pigs fed diets containing industry levels of trace minerals were heavier (P < 0.05) and had a higher (P< 0.05) than average daily gains compared to those that received a diet containing lower levels of trace minerals. Faecal zinc excretion was significantly lower (P < 0.05) in pigs fed with lower dietary zinc levels. Copper, manganese and iron excretion were not affected (P > 0.05) by the dietary levels of these trace minerals. Plasma trace mineral concentrations were not affected by the dietary treatment.

Field experiences with early pregnancy diagnosis by progesterone-based ELISA in sows.

In four Kenyan pig breeding units the pregnancy diagnosis of sows has been carried out in two groups: Group 1 (n = 1911): the sows were transrectaly pregnancy tested between Days 17-22 post-mating by ultrasound. Sows testing non-pregnant immediately received one dose of 400 IU pregnant mare serum gonadotropin (PMSG) (equine chorion gonadotropin, eCG) and 200 IU human chorion gonadotropin (hCG). On showing signs of oestrous, the animals were subsequently artificially inseminated (AI). Group 2 (n = 1923): sows were pregnancy tested by serum progesterone (P4)-based enzyme-linked immunosorbent assay (ELISA) on Day 17 post-breeding. P4 concentrations were categorized as positive (> 5 ng/ml) or negative (< 5 ng/ml). Sows testing nonpregnant immediately received one dose of 400 IU PMSG and 200 IU hCG by injection, and were subsequently artificially inseminated. The following parameters were evaluated: sows diagnosed non-pregnant, days from first post-weaning insemination until the sows were inseminated at their first return to oestrus; farrowing rate and total piglets born and number of live-born piglets in litters. The percentage of sows diagnosed non-pregnant in the two groups, as well as the totals of born piglets and of live-born piglets in litters did not differ significantly between the two groups. The number of days from the first post-weaning mating until the sows were artificially inseminated at their first return to oestrus and the administration of eCG and hCG was shorter (P < 0.01) and farrowing rate was higher (P< 0.01) in the ELISA-tested sows.

Evaluation of pyelonephritis in culled indoor and outdoor high parity sows.

UNLABELLED: The present trial was conducted in Hungary in neighboring large indoor and outdoor pig production units, belonging to the same breeding company. Rejected kidneys from 201 (out of 241; 83.4%) outdoor, and 191 (out of 512, 37.3%) indoor high parity sows, with previous history of recidiving postparturient fever and excessive postparturient vulvovaginal discharge were gross pathologically bacteriologically, and histologically evaluated. All rejected kidneys revealed chronic pyelonephritis. In outdoor sows Escherichia (E.) coli and Actinobaculum (A.) suis were cultured from all kidneys. Besides E. coli and A. suis, Clostridium spp., Arcanobacterium pyogenes, gram-positive streptococci (enterococci, Streptococcus faecalis), staphylococci (Staphylococcus (S.) albus, S. epidermis, S. aureus), Erysipelothrix rhusiopathiae, and Klebsiella spp. were concurrently found in 131 (64.7%) kidneys; Pseudomonas aeruginosa, Citrobacter, Pasteurella multocida, Proteus spp. were concurrently found beside E. coli and A. suis in 71 (35.3%) kidneys. In indoor sows E. coli and A. suis were cultured from all kidneys as well. Pseudomonas aeruginosa, Citrobacter, Pasteurella multocida, Proteus spp. were found beside E. coli and A. suis in 21 (11%) kidneys. However only 6 sows (3.1%) revealed the concurrent presence of Clostridium spp., Arcanobacterium pyogenes, gram-positive streptococci (enterococci, Streptococcus faecalis), staphylococci (S. albus, S. epidermis, S. aureus), Erysipelothrix rhusiopathiae, and Klebsiella spp. IMPLICATIONS: in Eastern European climate, more high parity outdoor sows with recidiving postparturient fever and vulvovaginal discharge have pyelonephritis and higher diversity of pathogenic bacteria in the renal pelvis compared with indoor sows.

Concurrent swine erysipelas and Clostridium novyi infections associated with sow mortality in outdoor sows in Kenya.

A sudden increase in sow mortality was reported from a large outdoor pig-breeding unit in Kenya. The sows showed pyrexia and diamond shaped to confluent skin lesions ante-mortem. Gross pathological examination of the carcases was performed and organ samples (heart, liver, kidney, spleen, mandible lymph nodes) were sent for further diagnostic investigation. Based upon the clinical, gross- and microscopic-pathological signs, bacteriological findings and toxin testing, concurrent infection with Erysipelothrix rhusiopathiae and Clostridium novyi was diagnosed as the cause of the sow mortality.

Efficacy of oral vaccination against swine erysipelas in growing-finishing pigs in a clinically infected Slovakian pig herd.

In a large Slovakian growing-finishing pig production unit, the effects of oral vaccination against swine erysipelas (SE) were investigated in three groups of pigs of 10 weeks of age. In group 1, the pigs were vaccinated intramuscularly at 1 and 3 weeks after arrival in the growing-finishing barn using an Erysipelothrix rhusiopathiae bacterin. Group 2 pigs were vaccinated at the same time as group 1 using an oral avirulent live SE vaccine administered through drinking water; the pigs in the third group were placebo treated. Clinical signs of acute SE, arthritic changes, average daily weight gain (ADG), feed conversion ratio, and mortality were evaluated. None of the pigs in groups 1 and 2 but 31.7% of the control animals (group 3) showed typical clinical signs of acute SE. More (P<0.01) non-vaccinated pigs had chronic arthritic changes compared with groups 1 and 2. No significant differences in mortality were recorded between the groups. Groups 1 and 2 had higher (P<0.05) ADG and lower feed conversion ratios compared with group 3 pigs. The results demonstrated that the oral avirulent live culture was efficacious in significantly reducing the clinical symptoms caused by E. rhusiopathiae infection, so enhancing the pigs' performance.

Tail-biting in outdoor pig production.

A study was performed in five identical outdoor production units in the same geographic area using growing-finishing pigs of similar genetic makeup, age, diet and feed management. The severity of tail-biting (TS) was scored 1-4. The average group prevalence of bitten tails at slaughter on different farms was between 14.1+/-2.1% and 20.1+/-3.0% (P<0.05). The odds of a barrow being bitten were 2.9 times higher than those for a gilt. The most frequently recorded score of bitten tails was TS3, indicating moderate wounds with low grade infection. The prevalence of bitten barrows was positively correlated with the percentage of gilts in a group (r = 0.54, P<0.001). Pigs with zero TS score had no significantly higher weights at slaughter compared to pigs with a score of TS1. As the TS increased from 1 to 4, weights decreased (TS 1 to TS 2 to 4, P<0.05). TS 3 and 4 were positively (P<0.001) associated with subsequent carcass condemnation. We concluded that outdoor rearing does not prevent tail-biting.

Seasonal infertility in Kenyan pig breeding units.

Reproductive performance of 12 Kenyan pig breeding units (56-299 sows per unit) of similar feeding, genetics and health status were evaluated from October 2003 to October 2004 during hot and cooler periods. Sows during cooler months of the year (April to October, average temperature between 08:00 and 17:00: 25.2 +/- 2.2 degrees C) had shorter (P < 0.01) weaning to service intervals (7.9 +/- 2.2 days vs. 12.7 +/- 2.7 days, respectively), less (P < 0.01) regular returns to service (5.7 +/- 1.9% vs. 9.9 +/- 1.9%, respectively), higher (P < 0.01) farrowing rates (80.1 +/- 4.4% vs. 70.8 +/- 3.8%, respectively), and larger born (10.0 +/- 1.1 vs 9.1 +/- 1.7, P < 0.05) and weaned litter sizes (9.2 +/- 1.2 vs. 8.0 + 1.3, P < 0.05) compared with the time periods of high ambient temperature (November to March, between 08:00 and 17:00: 37.2 +/- 3.3 degrees C). It was concluded that a high ambient temperature is a risk factor for reproductive performance in pig breeding units.

Gross pathological findings in sows of different parity, culled due to recurring swine urogenital disease (SUGD) in Kenya.

In a large Kenyan production unit the urogenital organs and mammary glands of 771 sows, culled due to recurring swine urogenital disease (SUGD) were subjected to necropsy Necropsy findings were analysed separately according to parity group of the sows [parities 2 (n = 252); 3-5 (n = 250); and > 5 (n = 269)]. Sows of higher parities had more pathological changes in their ovaries, uteri, vaginas, cervices, urinary bladders, kidneys and mammary glands compared to parity 2 sows (P < 0.05 and P < 0.01, respectively). Parity 2 sows had more ovarian degeneration, mucosal hyperaemia, congestion in the bladder, and acute purulent exudative mastitis than parity > 5 sows (P < 0.05 and P < 0.01, respectively).

Risk factors associated with Brachyspira hyodysenteriae PCR-positivity in East-European pig production units.

UNLABELLED: The objective of the present study was to determine the risk factors for swine dysentery in East-European middle-to-large sized, farrow-to-finish units, with separate breeding and grower-finisher facilities. Samples of faeces from 10 breeding animals (3-10% of the female inventory) and 10 grower finisher pigs (80-140 days of age) were collected for polymerase chain reaction testing (PCR) for Brachyspira hyodysenteriae (B. hyo). Of 139 farrow-to-finish units, 51 (36.7%) were positive, 49 (35.3%) were negative, and 39 (28.1%) were inconclusive for B. hyo by PCR. In breeding subunits, twelve variables passed the screening criterion for risk factors (P < .2) for B. hyo PCR positivity. The odds of the breeding subunits being B. hyo PCR positive were 3.5 times greater when the grower-finisher subunit was positive and the fibre content of the diet was > 6%. Use of 'all-in-all-out' farrowing policy and having >60% multiparous sows each reduced the odds of being B. hyo PCR-positive by 4-fold. In grower-finisher subunits, fourteen variables passed the screening criterion for risk factors (P < .2) for B. hyo PCR positivity. B. hyo PCR-positive status of the breeding subunits and higher fibre content of the diet were the most influential variables, with the odds of the grower-finisher subunits being B. hyo PCR positive being almost 8 times greater when the breeding subunit was also B. hyo PCR positive. Grower-finisher B. hyo PCR positivity was also associated with the percentage of pigs housed on concrete slats, with the odds of being positive being 7.5-times higher for subunits where more that 70% of the animals were kept on concrete slats compared with all other floor types. There was a strong association between grower-finisher status and whether the animals were on outdoor lots, with the odds of being B. hyo PCR positive being substantially lower for pigs on outdoor lots compared with all other surfaces. IN CONCLUSION: All-in-all-out management in the breeding units, B. hyo negativity of adjacent grower-finisher units, high fibre content of the diet, and older parity structure in a sow herd may reduce the risk of swine dysentery. In grower-finisher units, slatted flooring is associated with a higher risk, while B. hyo negativity of the breeding units, the fibre content of the diet, and outdoor production are associated with lower risk of swine dysentery.

Short communication: effects of a gonadotropin application on seasonal subfertility in pigs.

In this study the reproductive performance of weaned sows in a large production unit was evaluated during periods of high (> 35 degrees C) summer temperatures. Only weaned sows of parity 2-6 (a total of n = 3386) were evaluated in two groups in 13 replicates: Group 1 (n = 1694): The sows were treated subcutaneously with 400 I.U. of Gonadotropinum sericum (pregnant mare serum gonadotropin, PMSG [eCG]) and 200 I.U. of Gonadotropinum chorionicum (human choriongonadotropin, HCG [hCG]) on the day of weaning. Group 2: (n=1692). The sows received subcutaneously 4 ml of physiological NaCl solution on the day of weaning. Weaning to service intervals, regular and irregular returns to service, farrowing rates, and subsequent litter sizes were evaluated. Control sows had longer (P < 0.01) weaning to service intervals and more (P < 0.01) regular returns to service during hot weather periods compared with the gonadotropin treated sows. Irregular returns to service were low and showed no significant differences between the treated and non-treated sows (1.4+/-0.3 % vs. 1.5+/-0.4 %). Farrowing rates and litter sizes were significantly (P < 0.01) better in the treated compared with the non-treated sows.

Effects of oral vaccination against Lawsonia intracellularis on growing-finishing pig's performance in a pig production unit with endemic porcine proliferative enteropathy (PPE).

The aim of the present study was to evaluate the effect of oral vaccination against Lawsonia intracellularis (LI) on growing-finishing pig's performance. In a large Hungarian growing-finishing pig production unit, pigs with positive LI status were randomly divided into 2 groups and treated as follows: Group one: growing pigs (n = 4112) were LI vaccinated with an avirulent oral live vaccine (Enterisol Ileitis Boehringer Ingelheim Vetmedica, Inc., St. Joseph, USA). Group two: growing pigs (n = 4188 pigs) have not received LI vaccination. Culling and mortality rates, reasons for culling or mortality, and average daily weight gain were evaluated. Porcine proliferative enteropathy (PPE) caused culling and mortality rates were lower (0.2 % vs. 14.9 %, P < 0.001), and vaccinated pigs had lower none-PPE caused culling and mortality rates compared with the non-vaccinated ones (1.4 vs. 2.6 %, P > 0.05). While systemic infections and social stress or cannibalism related culling or mortality were significantly (P < 0.05) lower in vaccinated than in non-vaccinated pigs, reasons for culling or mortality due to non-LI caused diseases were non-significantly different between the vaccinated and non-vaccinated pigs. Average daily weight gain was higher (P < 0.05) in the LI vaccinated group of animals compared with the non-vaccinated ones (780 +/- 45 g vs. 660 +/- 71 g). The present results indicate that that LI vaccination does not only prevent PPE, but might result in more resistance and tolerance against other infectious and management caused losses.

Oral vaccination against swine erysipelas--field experiences in Croatia.

In order to prove the effects of mass application of oral erysipelas vaccine via drinking water, in a farrow-to-finish production unit in Croatia, the growing-finishing animals were divided into 3 groups and treated as follows:--Group 1 (n=199) was vaccinated intramuscularly against swine erysipelas at 1 week and 3 weeks after arrival in the growing-finishing facility with a swine erysipelas bacterin.--Group 2 (n=199) were vaccinated at the same time with an avirulent culture of Erysipelothrix rhusiopathiae oral vaccine through drinking water.--Group 3 (n=200) was not vaccinated. Animals with clinical signs of swine erysipelas, chronic progressive arthritis at slaughter, mortality, average daily weight gain during the growing-finishing phase were evaluated. None of the pigs in the groups 1 and 2 showed clinical signs typical for acute swine erysipelas. Twenty-four of the pigs (12 %) in group 3 had pyrexia and skin lesions typical for swine erysipelas. Fifteen pigs in group 1, 13 pigs in group 2, and 63 pigs in group 3 had chronic progressive arthritis (group 1 and 2 vs. group 3: P < 0.01). No significant differences in mortality were recorded between the groups. Group 1 and 2 had higher (P < 0.05) average daily weight gains compared with the group 3.

Lactation weight loss influences subsequent reproductive performance of sows.

UNLABELLED: In order to examine the effect of different lactation weight losses of sows of different parity on subsequent reproductive performance, the present trial was performed in German (n = 4) and Slowakian (n = 11) indoor pig breeding units (n = 1677 sows evaluated). Weaning-to-service-intervals, farrowing rates and total-born litter sizes in sows with different lactation weight losses were compared. Sows were categorized according to lactation weight losses of <5%, 5-10%, 11-15%, 16-20%, >20%. Lactation weight losses exerted a quadratic effect (P < 0.01) on weaning-to-service-intervals. When analyzed across parity categories, with parity category included as a fixed effect, the weaning-to-service-intervals appeared to be minimized at lactation weight losses of <5%. Weaning-to-service-intervals increased (P < 0.05) when lactation weight losses increased above 5% for parity 1 sows, but not until lactation weight losses exceeded 10% for animals of parity 2 and more. There was a parity effect observed at lactation weight losses of <10%, P < 0.05, but the difference was not significant any more at lactation weight losses of >10%. Lactation weight losses >10% had a negative (P < 0.05) effect on subsequent farrowing rates to first service. The difference was higher (P < 0.01) in sows with lactation weight losses >20%. Lactation weight losses exerted a negative (P < 0.001) effect on total-born litter sizes in parity 1 versus parity >5 and parity 1 versus parity 2-5 sows at lactation weight losses of >10%. CONCLUSION: As weight loss of sows during lactation increases subsequent reproduction performance decreases.

A new periparturient disease in Eastern Europe, Clostridium difficile causes postparturient sow losses.

Postparturient sow losses caused by Clostridium difficile have not been reported in the veterinary literature. Recently in Croatia, in a large outdoor production unit with suboptimal environmental conditions, a sudden increase in postparturient sow mortality was diagnosed. After postpartal application of enrofloxacine to postparturient mastitis metritis agalactia (MMA) suffering sows, diarrhea, respiratory distress, and mortality of these sows were recorded. While 13% of MMA suffering and treated sows died, only 0.4% of the non-treated (no MMA suffering) sows died postpartum. Gross pathology revealed mesocolonic edema, hydrothorax, and ascites. Microscopic examination showed scattered foci of suppuration in the colonic lamina propria and accumulation of neutrophils and fibrin on colonic mucosa. Anaerobic cultures of the colon yielded heavy growth of C. difficile. Enzyme immunoassay revealed C. difficile toxins A and B. C. difficile infections of postparturient MMA suffering sows may be associated with environmental stress, the application of antibiotics, or both. C. difficile infections are an impending danger in Eastern Europe and does not only raise animal welfare issues, but seriously inflict the economical well being of outdoor production units.

Seasonal infertility in large pig production units in an Eastern-European climate.

OBJECTIVES: To demonstrate the occurrence of seasonal infertility of sows in large production units in Eastern Europe. DESIGN: Weaners in this trial originated from a 1000 sow Croatian herd that weaned piglets at 14 or 28 days of age. The production records of 15 indoor (795 to 1849 sows per herd) pig farms with identical feeding, similar genetics and health status, were evaluated. The reproductive performance of sows when the average daily (9 am to 4 pm) temperature was more than 35 degrees C, was compared with the weeks when it was lower than 30 degrees C. RESULTS: During periods of high temperature (> 35 degrees C) sows had significantly (P < or = 0.05) longer weaning to service intervals and more regular returns to service (P < or = 0.05) compared to weeks of less than 30 degrees C daily temperature in the same summer season. Irregular returns to service were low and showed no significant differences during the same time periods. Farrowing rates and total litter sizes were lower (P < or = 0.05) for periods of higher than 35 degrees C daily temperature compared to weeks of less than 30 degrees C daily temperature in the same summer season. CONCLUSION: When daily temperatures are higher than 35 degrees C, reproductive performance is likely to be depressed in large pig production units.

The effect of intravaginal applied gonadotropin-releasing hormone agonist on different oestrous parameters and reproductive performance in post weaned sows.

In a Hungarian large breeding unit, 481 weaned sows were assigned to three groups and were treated as follows. Sows in Group 1 (Control, n=161) were artificially inseminated (3.01 +/- 0.4 times) during their standing reflex; sows in Group 2 (n=160) were artificially inseminated 3 times at 12-hour intervals, independent of detection of oestrus and immediately after administration of a GnRH-agonist at 96 hours postweaning; and sows in Group 3 (n=160) were artificially inseminated 3 times at 12-hour intervals, beginning at their standing reflex after administration of a GnRH-agonist. Pre-trial daily average lactational feed intake, average daily feed intake from weaning to oestrus, oestrus within 6 days of weaning (%), ovulation within 6 days of weaning (%), wean-to-oestrus interval (h), duration of oestrus (h), follicle size (mm), interval from oestrus to ovulation (h), subsequent day 24 pregnancy rate (%), farrowing rate (%) and total number of pigs born were evaluated. Pre-trial average daily voluntary lactational feed intake was 7.1 +/- 0.5 kg in Group 1, 7.2 +/- 0.4 kg in Group 2, and 7.3 +/- 0.7 kg in Group 3 (P > 0.05). Average voluntary daily feed intake from weaning-to-oestrus was 4.3 +/- 0.9 kg in Group 1, 4.2 +/- 0.8 kg in Group 2, and 4.1 +/- 0.5 kg in Group 3 (P > 0.05). Oestrus was detected within 6 days of weaning in 143 (88.8%) sows in Group 1, 143 (89.4%) sows in Group 2, and in 142 (88.8%) sows in Group 3. Follicle size did not differ (P > 0.05) among the groups. In Group 1, 83.2%, in Group 2, 90.6%, and in Group 3,91.3% of the sows ovulated within 6 days of weaning (P < 0.05), but there were no significant (P > 0.05) differences in 24 Day pregnancy rates (81.4%; 91.3%; and 92.5%). Farrowing rates were in Group 1, 84.5%, in Group 2, 91.3%, in Group 3, 91.9% (P > 0.05). Wean-to-oestrus interval was 115.5 h in Group 1, 114.9 h in Group 2, and 115.7 h in Group 3 (P > 0.05). Duration of oestrus was significantly shorter in Group 2 (41.9 h) and Group 3 (42.1 h) than in Group 1 (68.3 h) (P < 0.001). Similarly, the interval from oestrus to ovulation was significantly different (P < 0.01) between the groups (Group 1, 49.0 h Group 2, 32.0 h, and Group 3, 31.1 h). Sows in Group 2 (12.7) and Group 3 (12.6) had a significantly higher (P < 0.01) number of pigs born than sows in Group 1 (n = 10.9). The interval between oestrus and ovulation was highly and positively correlated (r = 0.83) with the duration of oestrus.

Maladaptive behavioural patterns of early weaned, indoor raised pigs.

The objective of the present study was to investigate the growth rate and maladaptive behaviour of early (day 14 of lactation) or late (day 28 of lactation) weaned pigs of either sex kept under different light intensities. Maladaptive behaviour was diagnosed when piglets were kept under a high light intensity but not when kept under a low light intensity. The time, spent engaged in maladaptive behaviour was not higher for barrows than for gilts. Lesions on 'recipient' animals were more severe in larger pigs with a greater rate of weight gain than in smaller ones. 'Perpetrator' pigs grew more slowly during the 46 days after weaning (P = 0.0013) than the non-preparator-pigs. 'Recipient' animals were significantly heavier and had higher rates of weight gain (P = 0.0003) than the 'perpetrator' pigs.

The course of acute-phase proteins and serum cortisol in mastitis metritis agalactia (MMA) of the sow and sow performance.

The objective of this study was to evaluate changes in acute-phase proteins (APPs) during mastitis metritis agalactia (MMA) in sows. Sows with MMA (group one, n=15) and healthy sows (group two, n = 15) were evaluated at days 0, 5, 10, 15, and 20 postpartum. Number of total born, liveborn, stillborn, and mummified pigs did not differ significantly between the groups. Preweaning mortality was higher (P < 0.001) among MMA sows than among healthy control animals. The offspring of healthy sows had higher (P < 0.05) weaning litter weights than the off-spring of MMA sows. Mean serum alpha 1-acid glycoprotein (AGP) concentrations were higher in MMA sows on the days 1 (P < 0.05), 5 (P = 0.05), and 10 (P < 0.001) post partum. Mean serum haptoglobin (HPT) was higher in MMA sows on days 1, 5 (P < 0.001), and 10 (P < 0.05) of lactation. Cortisol serum concentrations up to day 10 post partum were higher (P < 0.001) in MMA sows than in healthy sows. AGP was negatively correlated with litter weight, indicating that activation of the cellular immune response in sows negatively affects the growth rate of suckling piglets. Correlations were found between the overall means for weight, acute-phase proteins, and serum cortisol concentration.

Effect of gilt seropositivity to Lawsonia intracellularis (LI) on their offspring's seropositivity to LI and on diarrhoea after a pure-culture challenge.

This study was done in a large Croatian pig-production unit. Blood samples from late-pregnancy gilts were tested by an indirect immunofluorescence-antibody (IFA) serum assay for Lawsonia intracellularis (LI). Ten IFA-positive and 10 IFA-negative gilts were selected. The 2-week-old piglets (97 from positive gilts, and 98 from negative gilts) were inoculated intragastrically with pure culture of LI. All pigs were tested until slaughter for seroprevalence of LI. Blood samples were collected at 5, 8, 11, 14, 17, 20, 23 and 26 weeks of age. Seropositivity in offspring of IFA-negative gilts was highest at age 5 weeks (84%) and declined gradually from week 11 to only 10% at week 26. At the same time, the offspring of IFA-positive gilts showed lower and faster-decaying seroprevalence: only 32% at week 5 and 0% starting at week 17. There was no difference in the pen-days of diarrhoea between the offspring of LI-seropositive and -seronegative gilts.

Prostaglandin F2alpha supplemented semen improves reproductive performance in artificially inseminated sows.

The objective of this study was to assess the effects of the addition of prostaglandin F2alpha (PGF2alpha) to semen, to increase reproductive performance in sows. Sows in 11 large production units, were inseminated (AI) either with PGF2alpha enriched fresh semen (group 1, n=1258) or with untreated fresh semen (group 2, n=1101). Conception rate, regular return to estrus, farrowing rate, subsequent total and live-born litter size, subsequent weaning to estrus intervals, pigs born and pigs weaned per sow per year were evaluated. Conception and farrowing rates, as well as regular returns to estrus were altered beneficially (P<0.001) with PGF2alpha supplemented semen. Subsequent total-born (P<0.06) and subsequent live-born (P<0.15) litter size, as well as subsequent weaning to estrus intervals (P<0.22), were not affected to the same extent. Total pigs born (P<0.05) and pigs weaned (P<0.04) per sow per year were increased by using PGF2alpha supplemented semen.