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.     

The effect of different zootechnical practice methods on the duration of labor in swine with reference to the body condition of the sow]

In a single large pig production unit of 6000 breeding sows, seven groups of 100 sows each were formed at random on the 110th day of pregnancy. Each group was evaluated and divided according to body condition in three subgroups. The groups were treated as follows: Group 1 received a single 3 mg intramuscular dose of alfaprostol on the 113th day of pregnancy; Group 2 received a single 3 mg intramuscular dose of alfaprostol on the 113th day of pregnancy, followed 24 hours later by a single intramuscular dose of 10 IU oxytocin; Group 3 received a single intramuscular dose of 10 IU of oxytocin after the birth of the first piglet; Group 4 received a single 100 mg intramuscular dose of prednisolone on 113th day of pregnancy; Group 5 received a single 0.2 mg intramuscular dose of carbamylcholine on the 113th day of pregnancy; Group 6 received feed containing 12% fiber, at 3 kg per sow per day from the 110th day of pregnancy; Group 7 received a 3 ml dose of physiologic NaCl solution i.m. on the 114th day of pregnancy. The parameter "duration of parturition" was evaluated. Groups 4 (prednisolone), 5 (carbamylcholine) and 6 (fiber) showed a shorter duration of parturition when compared to groups 1, 2, 3 and 7. The subgroups 5 in each group showed a longer parturition time, when compared to subgroups 3 and 4.     

The effect of season and vaccination for Glässer's disease and post-weaning Colibacillosis in an outdoor pig unit endemically infected with virulent strain of Haemophilus Parasuis serotype 5 and pathogenic Escherichia coli

The objective of this field trial was to determine if vaccination against Haemophilus parasuis serovar 5 (HPS 5) and pathogenic serotypes of Escherichia coli would improve nursery pig performance in an outdoor unit in different seasons. The unit was concurrently infected with HPS 5 and with different serotypes of E. coli. All piglets were born to HPS 5 vaccinated sows. The trial was carried out in four (two summer and two winter) groups. Group 1 (E. coli and HPS vaccinated, summer season) (n = 362): Piglets were vaccinated pre-weaning with inactivated E. coli-VT2e-toxin and post-weaning against HPS 5. Group 2 (non-vaccinated, summer season) (n = 349): Piglets were not vaccinated. Group 3 (E. coli and HPS vaccinated, winter season) (n = 358): The animals were analogously treated as Group 1. Group 4 (non-vaccinated, winter season) (n = 353): Piglets were not vaccinated. The following parameters were evaluated: A: average daily nursery weight gain (ADG), B: nursery mortality, C: feed efficiency (FE). No significant weight differences were detected within the vaccinated and non-vaccinated summer or winter raised groups of weaners. Summer raised weaners were significantly (P<0.05) heavier from day 35 on than winter raised animals. ADG and FE of summer raised pigs were significantly better (weeks 1-3 P<0.05; fourth week post-weaning P<0.01) during the nursery period than that of the winter raised groups. Winter raised vaccinated weaners showed during the last week of nursing significantly (P<0.05) better daily gain and feed efficiency compared with the non-vaccinated winter raised animals. Non-significant ADG and FE differences were detectable between the summer raised vaccinated or non-vaccinated groups of pig. Winter raised non-vaccinated animals suffered significantly (P<0.05) higher nursery mortality (10.63%) compared to the winter raised vaccinated animals. Implication: In cases of concurrent infections with HPS 5 and with different serotypes of E. coli, especially during winter season, vaccination against both diseases is suggested.     

The effect of a homologous bacterin given to sows prefarrowing on the development of Glässer's disease in postweaning pigs after i.v. challenge with Haemophilus parasuis serotype 5

The trial was carried out to evaluate the impact of maternal antibodies on the development of Gl?sser's disease after i.v. exposure of weaned pigs with a homologous serovar of Haemophilus parasuis (HPS). Two groups of weaned pigs were formed. Group one VI (n = 10): born to vaccinated sows, weaners i.v. challenged one week postweaning and euthanatized 14 days postweaning. Group two NVI (n = 10 wearners): born to non vaccinated sows, i.v. challenged one week postweaning euthanatized 14 days postweaning. One week postweaning all weaners were i.v. inoculated with HPS serovar 5. The following parameters were evaluated: clinical signs (depression, centralnervous signs, fever, lameness), macroscopic lung, pleura, peritoneum, liver and joint changes, and mortality. All trial sows were HPS seronegative prior to vaccination. The HPS vaccinated sows were proven seropositive on day 3 p.p. (values > 0.24), the non vaccinated ones were tested seronegative (values < 0.23). The progeny of sows vaccinated prefarrowing with two doses of HPS serovar 5 bacterin were partially protected against HPS caused clinical and pathological signs. The majority of clinical signs as fever, depression, recumbency, lack of response to verbal stimuli and lameness showed significant (P < 0.05) milder clinical symptoms in VI than in NVI animals. Respiratory signs (P = .169) and involvement of the central nervous system as ataxia, muscular tremor, incoordination of hind legs and convulsions (P = 1) showed no significant differences between the groups. Except lesions of pericard (VI vs. NVI, P = .14) and pleura (VI vs. NVI, P = .14) there were significant (P < 0.05) macroscopic differences at necropsy in lung, liver, joints and cerebrospinal fluid between the offspring of vaccinated sows and the ones of non vaccinated dams. No HPS were isolated from the nasal mucosa of the pigs prior to inoculation. HPS serovar 5 was recovered at necropsy from the nasal mucosa of all pigs in both groups. One pig from group VI presented in all examined organs the presence of HPS serovar 5. The remaining animals in group VI revealed in lung, pericard, pleura, liver, joints and cerebrospinal fluid no presence of HPS. The rate of isolation between VI and NVI groups revealed a significant (P < 0.05) difference. All the survived piglets of group NVI showed positive ELISA titres against HPS serovar 5 (values > .24). The piglets that died or were euthanatized before the end of the study have not been subjected to ELISA serological testing. One piglet died in group VI before the end of the study. Non of the remaining animals in group VI showed seroconversion to HPS serovar 5. Implications: Vaccination of sows did not influence the colonisation of nasal mucosa, but progeny of sows vaccinated prefarrowing with two doses of HPS serovar 5 bacterin were partially protected against HPS caused diseases.     

Influence of the timing of an early postnatal booster vaccination on some fertility parameters in sows

In a large pig production unit, with high prevalence of E. coli caused postpartal urogenital diseases of the breeding animals and diarrhoea of the piglets, the pregnant sows received during their late pregnancy a Porcovac plus E. coli vaccination. The vaccinated sows were assigned to two experimental groups and were treated postpartal (p. p.) as follows: Group 1 (421 sows): received an E. Coli booster on the first p. p. day Group 2 (299 sows): received a booster on the 7th p. p. day The following parameters were evaluated: A: Weaning-estrus-intervals B: Farrowing Rate The results showed a significant (p < 0.05) shorter weaning-estrus-interval (Parameter A) in group 1 when compared to group 2 (7.21 +/- 1.04 vs. 9.84 +/- 1.11). Regarding parameter B (farrowing rate) the groups showed no significant difference (group 1: 89.9% vs. group 2: 91.8%). It is the opinion of the authors that in large pig production units with high incidence of urogenital diseases an early p. p. E. coli Booster should be performed, because of its positive effect on the weaning-estrus-intervals.     

Action of the vaccination of sows against E. coli infections with a subsequent postpartum booster

In an eastern european pig productions unit with high prevalence of suckling piglets diarrhoea during late lactation the following trial was conducted: The sows were assigned to an experimental and to a control group and were treated as follows: Group one (15 sows) were vaccinated with a single 2 ml dose of Porcovac Plus (H?chst Roussel Vet.) during their late pregnancy (gilts were vaccinated twice). Booster vaccination was performed between day 2-7 p.p. Group two (15 sows) were vaccinated during their late pregnancy the same was as the sows in the group one, but received no p.p. Booster. The following parameter were evaluated. A: Preweaning diarrhoea B: Preweaning mortality C: Three weeks weaning litter weights D: Postweaning mortality E: Average weight gain during the first 3 weeks postweaning The results revealed a marked difference between the groups (group 1: 16.1% vs. group 2: 23.3%) regarding preweaning diarrhoea (parameter A). A similar difference was to be seen regarding parameter B (preweaning mortality) between the groups (group 1: 7.5% vs. group 2: 10.7%). In spite of this there was a non significant difference as regards weaning litter weights (parameter C) between group 1: 59.2 +/- 2.4 kg and group 2: 57 +/- 2.2 kg. Postweaning parameters showed better results in the booster vaccinated group regarding both evaluated parameter as well. Regarding piglet mortality (parameter D) there was a marked difference between the group 1 (0.67%) and group 2 (2.1%) to be seen. Regarding average daily gain (parameter E) between group 1 (470 +/- 11 gr) and group 2 (380 +/- 9 gr) there was a significant difference (p < 0.05) to be discovered. It is the opinion of the authors that p.p. Booster vaccination of the sows is an economically important tool in large and small pig production units.     

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.     

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.     

限制母猪的体重损失

克罗地亚的研究表明了如何通过减少母猪泌乳期的体重损失来改善其繁殖性能