Factors associated with preweaning mortality on commercial pig farms in England and Wales

Data from 67 pig farms with a variety of farrowing systems were used to identify factors associated with preweaning mortality in British pig herds. The median mortality reported by the farmers was 10.7 per cent (interquartile range 8.5 to 14 per cent). There was a significantly higher mortality when the pigs were weaned when they were older. A multivariable Poisson model was developed into which the types of farrowing system on each farm and the age at weaning were forced. Factors associated with a lower preweaning mortality rate were insulating the farrowing building, providing extra heat at farrowing, giving the piglets iron injections, dipping their navels, using fan ventilation and using artificial lighting systems. Factors associated with a higher mortality rate were a later weaning age, the use of infra-red lamps rather than other forms of supplementary heat, and the use of a creep without any bedding.     

Factors affecting piglet mortality in loose farrowing systems on commercial farms

Crating sows in farrowing systems greatly restricts their normal behaviour (e.g. movement, nest-building, leaving the nest site for defecation), which is usually justified by the assumption that piglet mortality is higher with loose-housed sows. Based on experiments showing that this is not the case, farrowing crates were banned in Switzerland in 1997, with a 10-year transitional period. Since then, many farms have introduced loose farrowing systems, enabling an analysis of risk factors for piglet mortality in crateless farrowing systems based on a large sample size. Data from a Swiss sow recording scheme (UFA2000) were analysed using generalised linear mixed-effects models with an underlying Poisson distribution. Average total piglet mortality for the years 2002 and 2003 on 99 farms (N = 12457 litters) with loose farrowing systems amounted to 1.36 liveborn piglets per litter. The number of crushed piglets was 0.64 piglets per litter, whereas the number of piglets that died for other reasons was 0.72 piglets per litter.Herd size, pen size, possibility of confinement of the sow, presence of piglet protection bars and year of data collection did not significantly influence total piglet losses, losses due to crushing and losses due to reasons other than crushing. With greater litter size at birth, significantly more losses occurred due to all reasons (total, crushed, others). Total piglet mortality and losses for reasons other than crushing were significantly higher in older sows. Losses were therefore mainly attributable to sow-related characteristics rather than to the design of the farrowing pen.     

Risks associated with preweaning mortality in 855 litters on 39 commercial outdoor pig farms in England

A prospective longitudinal study was carried out on 39 outdoor breeding pig farms in England in 2003 and 2004 to investigate the risks associated with mortality in liveborn preweaning piglets. Researchers visited each farm and completed a questionnaire with the farmer and made observations of the paddocks, huts and pigs. The farmer recorded the number of piglets born alive and stillborn, fostered on and off and the number of piglets that died before weaning for 20 litters born after the visit. Data were analysed from a cohort of 9424 liveborn piglets from 855 litters. Overall 1274 liveborn piglets (13.5%) died before weaning. A mixed effect binomial model was used to investigate the associations between preweaning mortality and farm and litter level factors, controlling for litter size and number of piglets stillborn and fostered. Increased risk of mortality was associated with fostering piglets over 24 h of age, organic certification or membership of an assurance scheme with higher welfare standards, farmer's perception that there was a problem with pest birds, use of medication to treat coccidiosis and presence of lame sows on the farm. Reduced mortality was associated with insulated farrowing huts and door flaps, women working on the farm and the farmer reporting a problem with foxes.     

Influences of climatic parameters on piglet preweaning mortality in Thailand

Tropical Animal Health and Production - The objective of the present study was to determine the influences of temperature, humidity, and temperature–humidity index (THI) on piglet preweaning...     

Five-year trends in female pig mortality on commercial breeding farms in Japan

High mortality in female pigs on breeding farms is a critical problem in the U.S. swine industry. The objectives of this study were to determine whether female pig mortality on Japanese commercial farms increased; to investigate correlations between the mortality and herd-management factors, especially herd size and lactation length; and to determine herd repeatability in female pig mortality. A five-year annual measurement data between 1999 and 2003 were abstracted from recording files of 113 farms in Japan. The year-effects on measurements were analyzed by using repeated measures data between 1999 and 2003 in mixed-effects linear models. The annual mortalities for female pigs in 1999, 2000, 2001, 2002 and 2003 were 4.93%, 5.25%, 5.40%, 5.32%, and 4.85%, respectively. The year-effect on the female pig mortality was not found for the five years. Neither herd size, lactation length nor other management factors were found to be consistently correlated with female pig mortality for the five years. The repeatability of the mortality was 36.5% on commercial farms. In conclusion, female pig mortality did not increase during these five years in Japan. Herd size and lactation length were not risk factors for female pig mortality.     

Patterns of crossfostering and piglet mortality on commercial U.S. and Canadian swine farms

A data base of 300 farms using computerized records was used to examine the extent and timing of crossfostering being practiced in commercial herds in the Midwestern U.S. and Canada in 1994–1995. Crossfostering was used on 98% of farms. Across all farms, the mean percent of piglets crossfostered was 8.6%. Farms varied greatly in the age at which they moved piglets. The 20 farms that moved piglets the earliest after birth were classified as early-move farms and the 20 that moved the oldest piglets were classified as late-move farms. Early-move and late-move farms did not differ in herd size (P = 0.14), average parity of farrowed sows (P = 0.47) or age at weaning (P = 0.37). There were differences between early-move and late-move farms in percent of piglets fostered (P = 0.0001), pigs born alive/litter (P = 0.04), and pre-weaning mortality (P = 0.0005). A subset of late-move farms that were part of an integrated production group had unique production parameters that suggested inaccurate record-keeping.     

Timing and causes of piglet mortality in alternative and conventional farrowing systems

The causes and timing of piglet mortality were studied in different farrowing systems. In the first experiment 198 litters were recorded in three systems, two of which allowed the sows to move freely, and the third restricted them in conventional crates. More piglets were weaned from the conventional crates than from the open systems and they grew more quickly. More than half the liveborn mortality occurred during the first four days after parturition. In the open systems, 17 per cent and 14 per cent of the piglets born alive were crushed, compared with only 8 per cent in the crates. In the second experiment, 29 sows and litters were studied in detail in a communal pen system during the first seven days of lactation. Three-quarters of the liveborn mortality was due to crushing. The total number of piglets dying per litter, including stillbirths, was significantly associated with the total litter size and the sow's parity. The percentage liveborn mortality was significantly associated with the parity and body length of the sows and with the within-litter variation in the birth weight of the piglets. Individual birth weight was closely associated with percentage survival. Only 28 per cent of piglets weighing less than 1.1 kg at birth survived to seven days.     

内毒素对规模化猪场仔猪腹泻的危害

规模化猪场新生仔猪腹泻的发病率逐年提升,传统治疗方法应用抗生素杀死大量细菌的同时也释放大量的内毒素,导致仔猪腹泻治疗效果较差.不仅如此,母猪体内内毒素也通过胎盘屏障和乳汁传递给胎儿,增加仔猪腹泻的发病率,降低其免疫力而诱发其他致病性微生物对仔猪的感染能力.进而增加了仔猪腹泻的治疗难度,成为影响新生仔猪健康养殖的"瓶颈"...     

集约化猪场仔猪腹泻的病因及其控制措施

仔猪腹泻是集约化养猪生产条件下一种常见的多因素性疾病,是引起仔猪死亡的重要原因之一,常给养猪生产造成重大经济损失。仔猪腹泻基本上可以分为两大类。其一是病理性的,主要由传染性胃肠炎病毒、流行性腹泻病毒、产毒素性大肠杆菌、梭状芽孢杆菌、沙门氏菌、球虫等引起。这些     

Exploratory study of Mycoplasma suis (Eperythrozoon suis) on four commercial pig farms in southern Brazil

Mycoplasma suis (Eperythrozoon suis) was detected by PCR and Southern blot in 186 pigs (121 sows, 61 piglets and four boars) on four farms in southern Brazil. DNA was extracted from blood samples and a 16S rRNA gene fragment of M suis was amplified by PCR; Southern blot analysis was then performed on all the samples. Twenty-two of the sows (18.2 per cent) were positive by PCR, and 40 (33.1 per cent) were positive by Southern blot; only one piglet and one boar were positive. The packed cell volume and total plasma protein of the pigs and their PCR and Southern blot results were not significantly different on the four farms, but higher proportions of the pigs were positive by Southern blot than by PCR (P<0.05). The packed cell volume and total plasma protein concentrations of the M suis positive and negative sows were not significantly different.     

A cross-sectional study of the prevalence of foot lesions in post-weaning pigs and risks associated with floor type on commercial farms in England

We carried out a cross-sectional study during 2003 and 2004 to establish the prevalence and risk factors associated with floor type for commonly observed foot lesions in pigs aged 6, 8 and 14 weeks. The overall prevalence of foot lesions was 39.6% in 2283 pigs from 90 representative pig farms in England. The most prevalent lesions were heel/sole bruising (7.1%), heel/sole erosion (10.8%), heel flaps (8.4%) and toe erosion (11.6%). Pigs were kept on either solid (41%), partly slatted (28%) or fully slatted (31%) floors. Of the 104 pens with a solid floor, 26% of pens were outside with straw bedding on a soil base, 33% were indoors with deep bedding on solid concrete, 25% were partly deeply bedded on solid concrete and 16% were sparsely bedded on solid concrete. Only six of the pens with partly slatted floors were bedded.Multilevel logistic-regression models were built using data from 100 farms to examine the risks for individual foot lesions with prevalences >5%. The prevalence of toe erosions was positively associated with deep bedding, whereas deep bedding and soil floors were negatively associated with the prevalence of heel/sole erosions. Heel flaps and heel/sole bruising were both associated with slatted floors, possibly indicating a common aetiology. The greatest reduction in prevalence of all these lesions, from AFp calculations, would be achieved by moving pigs from slatted floors onto solid floors.     

Characteristics of commercial pig farms in Great Britain and their use of antimicrobials

A mail survey of 1889 pig producers in Great Britain with more than 100 sows or more than 1000 pigs was carried out to investigate their use of antimicrobials and other health-related management practices. The response rate was 25.5 per cent. Antimicrobials were most commonly administered in feed. Depending on the production system, between 60 and 75 per cent of the farms had used antimicrobials in their weaner rations and 20 to 62 per cent had used them in their grower rations. Antimicrobial injections had been used on 59 per cent of the farms. The use of antimicrobials in pigs of different age groups was variously associated with the scale of production, membership of a quality assurance scheme, the use of vaccination and whether the farmer thought the farm environment could be improved. Half the respondents (49 per cent) indicated that they used growth promoters in their weaners, but fewer used these in their growers (45 per cent) and finishers (34 per cent). Although 63 per cent of the farmers felt that the continued use of antimicrobials for disease prevention was justified, only 21 per cent felt that their continued use as growth promoters was justified.     

Relationship between postnatal piglet mortality,environmental factors and management around farrowing in herds with loose-housed,lactating sows

Abstract

The objective of this study was to investigate management routines and environmental factors influencing postnatal piglet mortality in commercial herds with individually loose-housed sows. Last year production records from 39 herds were used. We gathered information on specific routines as well as environmental factors by visiting every farm once. Herds practising moderate roughage feeding during pregnancy tended to have lower piglet mortality (p=0.06). Use of farrowing rails along all the sides of the pen resulted in lower piglet mortality than when no rails were present (p<0.01). Herds that hardly used any litter in the sow area at the time of farrowing had significantly higher piglet mortality than herds that used a moderate or large amount (p<0.05). Helping the piglets to obtain colostrum immediately after birth also reduced mortality (p<0.05), whereas other routines such as shutting the piglets inside the creep area while feeding the sow did not have any significant effect.     

Occurrence of Isospora suis in larger piglet production units and on specialized piglet rearing farms.

Mixed fecal samples of 264 litters from five piglet production farms (155-238 sows/farm) were investigated three times during the suckling period for the occurrence of Isospora suis over the period of 1 year. On all five farms Isopora suis was found to be a common endoparasite with infection rates being highest in litters of 3-4 weeks of age. By the end of the third investigation period the cumulative infection rate was 53.8% of the litters ranging from 20.0% to 81.5% for the single farms. During the suckling period the infection rate increased from 18.6% to 32.6% and then to 37.7%. Diarrhea was present in 66.3% of the sampled litters with the highest rates at the end of the suckling period. 63.4% of the litters which showed diarrhea and 34.8% of those without diarrhea excreted I. suis within the study period. Diarrhea was recorded for 78.2% of the I. suis-positive litters and for 52.5% of the Isospora-negative litters. In summer and fall the occurrence of I. suis was higher (66.3% and 61.0%, respectively) than in spring and winter (47.7% and 37.9%, respectively). In litters with diarrhea and pathogenic E. coli I. suis often occurred simultaneously. Above-average hygiene measures and mainly perforated pen floors seemed to lower the risk of isosporosis. With the exception of Strongyloides ransomi other parasites were not found in the fecal samples of suckling piglets. Two specialized piglet rearing farms, a conventional large-scale rearing unit and a farm managed according to the segregated early weaning (SEW) system were examined three times during the 6-7 week rearing period. In both units I. suis was common, but was not correlated with diarrhea. In the SEW unit the infection rates decreased from 37.5% to 20.2% and to 4.1%, while the infection rate in the conventional unit slightly increased from the first (17.2%) to the second (21.9%) investigation and stayed at this level at the third sampling.     

Evaluation of genetic, common-litter, and within-litter effects on preweaning mortality in a birth cohort of puppies.

OBJECTIVE: To determine relative impact of genetic, common-litter, and within-litter factors on puppy mortality. ANIMALS: 2,622 Boxer puppies of 413 litters born during a 14-month period. PROCEDURE: For each puppy, pedigree was determined, and litter in which it was born was registered. Overall mortality and mortality per specific cause of death were analyzed by use of a model that included an additive genetic effect, common-litter effect, within-litter effect, and regression of mortality on inbreeding coefficient. Relative importance of the effects was determined from estimates of the variance in mortality explained by each factor. RESULTS: 22% of the puppies died before reaching 7 weeks old. Stillbirth was the most frequent cause of death, followed by infection. Most observed differences were attributable to within-litter factors, which explained 67% of the variance in death attributable to infection and < or = 96% of the variance in death attributable to asphyxia. Common-litter factors were more important than additive genetic factors. Variance attributed to common-litter factors ranged from 2% for cheiloschisis, palatoschisis, or cheilopalatoschisis to 30% for death attributable to infection, and variance attributed to additive genetic factors ranged from 0% for asphyxia to 14% for euthanatized because of white color. Inbreeding coefficient had a significant effect on death attributable to infection, which increased 0.26% for each percentage increase of inbreeding. CONCLUSIONS AND CLINICAL RELEVANCE: Additive genetic factors have less impact on preweaning mortality than common-litter factors, which in turn have less impact than within-litter factors. Mortality attributable to infection increases significantly with increases in inbreeding.     

中国规模猪场腹泻调查

[目的 ]掌握猪腹泻在规模猪场(年出栏1000头)的流行情况和主要病原,分析疫病发生的风险因素。[方法 ]采用横断面研究方法,选取江西、河南、湖南、四川和广西5个省、区407个规模猪场,开展了问卷调查、现场调查和实验室检测。[结果 ]调查发现腹泻的场流行率为71.99%,腹泻的发生率与猪场规模呈负相关(R2=0.87),不同种类猪的流行率不同,母猪、育肥猪、保育猪和哺乳仔猪发生腹泻的流行率分别为3.48%(95%CI,2.24%-4.96%)、2.4%(95%CI,1.35%-3.63%)、12.78%(95%CI,10.25%-15.41%)和33.80%(95%CI,31.02%-36.86%)。多重logistic回归分析结果表明,腹泻的发生与饲养年限、车辆进场消毒以及产房温度等因素有关。     

Longevity, lifetime pig production and productivity, and age at first conception in a cohort of gilts observed over six years on commercial farms.

An observational cohort study was conducted using a producer group of 33 farms selected based on their completeness of reproduction data, including dates of birth, entry to a herd, and removal. Average lifetime pig production and parity at removal in a cohort of 2,265 females born in 1990 were 67.2 pigs born alive and 5.6 parities, respectively. Approximately 90% of farrowings occurred from the second through the fourth year from birth. Farrowing rates between parities of 2 and 4 were higher than other parities, and pigs born alive from parities 3 to 5 were the greatest among parities. The 10th and 90th percentiles of age at first conception were 227 and 322 days. Increasing the age at first mating was associated with low farrowing rate (P<0.01) in parity 0. Older age at first conception was associated with lower parity at removal, shorter reproductive herd life, and fewer lifetime pigs born alive (P< 0.01). Of the 2,265 breeding females, 253 (11.2%) were re-mated at parity 0 and farrowed. These sows with a record re-mating at parity 0 had lower parity at removal, less lifetime pig production and lower lifetime productivity than those with no re-mating at parity 0 (P<0.01). It is recommended that unbred gilts 230 days of age or older should be mated soon.