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.     

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.     

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"...     

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.     

Considerations on ethics and animal welfare in extensive pig production: Breeding and fattening Iberian pigs

The extensive pig production in Spain is traditionally characterised by: the use of the Iberian pig, an autochthonous breed perfectly integrated into the environment in which they have developed; a long duration of the productive cycle for about 23–24 months; a high level of animal welfare level, specially in the fattening process with freedom of movement and feeding base on natural sources: acorns and grass, and an equilibrated “dehesa” agro-forestry system where this activity has been developed. Nowadays, the introduction of more intensificated methods due to the increasing demand led to important changes, such as: the shortening of the productive cycle (10–12 months); freeing from the territorial base; changes during the fattening period, fattening with mixed feed and less animal freedom. All these facts may implicate a loss of the animal welfare condition. These circumstances lead us to question it from an ethical point of view.     

A longitudinal field study of mortality and Marek's disease in Norwegian and imported White Leghorns

High mortality during the first part of the laying period was observed in Norwegian White Leghorns during the period 1988–1992. A longitudinal field study with repeated measurement of cumulative mortality was undertaken in the period from January 1994 to January 1996 to investigate (1) the mortality and susceptibility to Marek's disease (MD) in the Norwegian strain (NB41) compared to two imported layers, (2) the effect of MD on the total cumulative mortality in the period from 16 to 32 weeks of age in White Leghorn flocks, and (3) the effect of MD as judged by repeated measurement of cumulative mortality in the same period. All five layer hatcheries and 67% of the pullet-rearing farms in Norway participated in the field study. The egg-production farms were sampled by convenience. Recordings for the whole period were completed for 169 flocks in 101 farms. The statistical analyses were performed using both a general fixed-effects linear model and a mixed model with repeated measurements, with total flock-level cumulative mortality and flock-level cumulative mortality in four-week intervals as outcome variables, respectively.

The overall cumulative flock-level incidence of MD was 12% (24% and 8% in NB41 and Lohmann White, respectively). MD was not recorded in any of the Shaver White flocks. A significant difference (p < 0.001) was found in (1) total cumulative mortality: 8.2% in the NB41 and 5.0% in the imported layers, and (2) ‘interval-specific' cumulative mortality: 0.36% in the NB41 and 0.15% in the imported birds. A strong relationship was also demonstrated between MD and repeated measurements of ‘interval-specific' cumulative mortality (p < 0.001) but not when cumulative mortality was used as an overall measure for the whole laying period (p = 0.11). The results from the repeated-measures analysis also indicated a stronger effect of MD on flock-level ‘interval-specific' cumulative mortality in the NB41 than in the imported hens. The different cumulative mortality and susceptibility to MD observed in the NB41, compared to the imported hens, shows that the farmers will be able to reduce their losses by replacing the NB41 strain with one of the imported strains.     

广西规模猪场猪呼吸道疾病综合征的病原学调查

为了解猪呼吸道疾病综合征(PRDC)在广西规模场猪群中的感染状况,采用PCR和RT-PCR方法,对2007～2009年期间采自广西13个市65个规模猪场的281份疑似PRDC感染组织样品进行了12种病原体检测。结果显示:73.85%(48/65)的猪场和71.87%(202/281)的组织样品为PRDC感染,其中,被猪繁殖与呼吸综合征病毒(PRRSV)、猪圆环病毒2型(PCV2)、猪瘟病毒(CSFV)、猪链球菌(SS)、猪伪狂犬病毒(PRV)、败血性波氏杆菌(Bb)、猪附红细胞体(E-su is)、猪流感病毒(SIV)、产毒素多杀性巴氏杆菌(T+PM)、副猪嗜血杆菌(HP)、猪细小病毒(PPV)和猪传染性胸膜肺炎放线杆菌(APP)感染(包括混合感染)的阳性样品分别占49.11%(138/281)、34.52%(97/281)、9.60%(27/281)、8.19%(23/281)、6.41%(18/281)、6.41%(18/281)、6.05%(17/281)、6.14%(15/281)、4.63%(13/281)、3.91%(11/281)、0.36%(1/281)和0.00%(0/281);单纯感染占28.11%(79/281);混和感染占43.77%(123/281)。二重、三重和四重混合感染分别占28.11%(79/281)、12.46%(35/281)和3.20%(9/281)。其中,以PRRSV+PCV2(+其他)混合感染形式较多见,占所有混合感染样品的52.03%(64/123)。细菌性病原体感染样品占20.28%(57/281),其中19.22%(54/281)为混合感染。可见:广西地区规模猪场普遍存在PRDC感染,其中PRRSV和PCV2是引起PRDC的主要病原;感染类型复杂多样,以PRRSV+PCV2(+其他)混合感染最为常见。     

海口地区商品猪场生产工艺和环境设计方法初探

地域气候差异、环境控制措施的选择对猪场设计及运行影响巨大。针对不同的养猪生产区，如何综合考虑气候特点对猪场进行标准化设计是满足猪场建成后正常运营的重要条件。海口市属华南地区，地处低纬度热带区域，年平均气温24℃，极端最高气温可达约41℃，平均相对湿度85％。文章针对海口地区特有的气候和地理环境特点，探讨了海口地区商品猪场在工艺设计、建筑设计和环境控制设计方面的设计思路，并通过案例分析进行了详细的说明。     

Risk factors associated with on-farm mortality in Swedish dairy cows

Dairy cow mortality (unassisted death and euthanasia) has increased, worldwide and in Sweden. On-farm mortality indicates suboptimal herd health or welfare and causes financial loss for the dairy producer. The objective of this study was to identify cow-level risk factors associated with on-farm cow mortality. Cows with at least one calving between 1 July 2008 and 30 June 2009 from herds enrolled in the Swedish official milk recording scheme with >40 cow-years were included. Each cow was followed from the day of calving until she calved again or left the herd (died, slaughtered or sold). The effects of potential risk factors on on-farm cow mortality were analysed using a Weibull proportional hazard model with a gamma distributed frailty effect common to cows within herd. The event of interest (failure) was euthanasia or unassisted death. An observation was right censored if the cow was slaughtered, sold, calved again or had an on-going lactation at 500 days after calving. The lactations were split into seasons (January to April, May to August and September to December) and at 30 and 100 days in milk in order to evaluate seasonal effects and the effect of disease in different lactation stages. Primiparous and multiparous cows were analysed separately. The highest hazards for both primiparous and multiparous cows were found for traumatic events and diseases, both in the lactation stage in which the cow died and in the preceding stage. The hazard was higher in early lactation and lower in 2nd parity compared to higher parities. Increased age at first calving (for primiparous cows), calving between January and April, dystocia and stillbirth also increased the mortality hazard. Differences were also found between breeds, between milk production parameters at first test milking and between management types. The results from this study show the importance of good management and preventive health actions, especially around calving, to avoid mortality in dairy cows.     

Associations between the proportion of Salmonella seropositive slaughter pigs and the presence of herd level risk factors for introduction and transmission of Salmonella in 34 Danish organic, outdoor (non-organic) and indoor finishing-pig farms

This paper evaluates the association between herd level risk factors for introduction and transmission of Salmonella in farms with three different production systems: organic, outdoor (non-organic) and indoor finishing-pig farms, and the presence of seropositive animals in the herds. Potential risk factors for Salmonella in the three pig production systems were identified through a literature review, and management information as well as serological data were collected in 34 pig farms: 11 organic farms, 12 outdoor farms, and 11 indoor farms. There were no general differences in the proportion of Salmonella seropositive animals in the organic, outdoor, and indoor pig farms. Correspondence analysis showed that the occurrence of seropositive animals in the herds was mostly associated to the risk of introducing Salmonella in the herds by purchasing and transporting growing pigs. No associations between herd risk factors for transmission and survival of Salmonella and seropositive animals in the herds were found.     

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.     

Farm-level factors associated with above-average production on pig farms in Evia, Greece

The aim of this study was to identify farm-level factors associated with above-average production of pig farms in Evia, Greece. Cross-sectional data on pig farm characteristics and management, farmer characteristics, worming practices, anthelmintics used, and the parasite loads of 10 randomly selected boars, sows, weaners, and fatteners were collected from 28 pig enterprises in the Evian region of Greece (74% of the total number of pig enterprises in this region). Above-average productivity was defined as weaning 18 or more piglets per sow per year. A multivariate logistic regression model found that employing immigrant workers reduced the odds of a farm being an above-average producer (OR 0.016, 95% CI 0.001–0.27), while having a veterinarian select the anthelmintic strategy significantly increased the odds of a farm being an above-average producer (OR 10.24, 95% CI 0.78–135.13). None of the gastrointestinal parasites under investigation were significantly associated with above-average productivity. It is concluded that despite the fact that endoparasite load was not significantly associated with above-average production, a quantification of the impact of intestinal worms on pig productivity is needed to know how much control can be envisaged for gastrointestinal worms before reaching the threshold at which it is no longer physically or financially reasonable to continue pursuing control.     

Seroprevalence and risk factors associated with Toxoplasma gondii infection in pig farms from Catalonia, north-eastern Spain

Seroprevalence and associated risk factors for Toxoplasma gondii infection in pigs were analyzed in 1202 sera samples, including sows and pigs of three, seven, 11, 15 and 20 weeks of age, from 23 farms in Catalonia, north-eastern Spain. Antibodies were tested by the modified agglutination test (MAT) at titers ?1:25. Antibodies to T. gondii were found in 228 samples (19.0%; 95% CI: 16.8-21.2). The individual prevalence in animals higher than 7 weeks of age was 22.8% (174/762; 95% CI: 16.6-29.0) and the within-farm prevalence ranged from 7.1% to 36.4%. Statistically significant differences were found among age classes. The risk factors significantly associated with T. gondii seroprevalence were the presence of cats, percentage of mortality at weaning and the presence of outdoor facilities in the farms. The seroprevalence observed in the present study indicates widespread exposure to T. gondii among domestic pigs in Catalonia, which may have important implications for public health.     

Retrospective analysis of trends and production factors associated with sow mortality on swine-breeding farms in USA

Of the 825 pig farms in USA that mailed in their electronic file containing production records, 604 farms were used to observe breeding-female mortality risk and related factors (herd size, lactation length, parity and season). Multiple regression was used to determine factors associated with annual mortality risk. Analyses of variance were used for comparisons of mortality risks among parity and season groups. Average annual mortality risks during the 1997 period was 5.68%. Average breeding-female inventories and average lactation length on USA farms were 733 and 18.3 days, respectively. Higher annual breeding-female mortality risk was associated with larger herd size, greater parity at farrowing and shorter lactation length (P<0.02). For example, as herd size increases by 500 females, mortality risk increases by 0.44%. Older parity was associated with higher mortality risks. Summer season was also associated with higher mortality risk. Using five-years’ records on 270 farms, annual mortality risk in 1997 was higher than those of 1993 and 1994, while average breeding-female inventory increased and lactation length decreased. It is recommended that producers, especially in large herds, pay more attention to breeding females.     

Investigations on the conjunctival goblet cells and on the characteristics of glands associated with the eye in the guinea pig

Objective To investigate the distribution and density of conjunctival goblet cells (GC) and to study the anatomy and microscopic characteristics of glands associated with the eye in the guinea pig. Procedures Twenty‐five guinea pigs were used. Meibomian gland openings were counted using biomicroscopy. Conjunctiva, eyelids and glands were embedded in glycol methacrylate and paraffin. Sections were stained with hematoxylin and eosin (H&E), periodic acid Schiff’s reaction (PAS) and Alcian blue (AB). Results Highest GC densities were found in the bulbar and palpebral region of the nasal conjunctiva (GC index: 13.7–16.4%). Lowest GC densities (GC index: 0.0–1.0%) were found in 3/4 limbal regions (nasal and temporal upper eyelid, temporal lower eyelid). Guinea pigs have 27.1 ± 3.0 (mean ± SD) meibomian gland openings in the upper lid and 25.7 ± 2.3 in the lower lid. Difference between upper and lower lid was significant (P = 0.037). Two subconjunctival sebaceous glands occur temporal to each eye. The Harderian gland is very large. In the lacrimal gland three different cell types were distinguished both according to the cell structure and histochemical staining. Conclusions Goblet cell densities are lower in guinea pigs than in dogs and horses. Positive staining with PAS and AB could be an indication that mucins are produced in the lacrimal gland. If so, they may contribute to the mucin layer of the tear film. Both the extraordinarily large Harderian gland and the subconjunctival sebaceous glands produce lipids and may contribute to the lipid layer of the tear film.     

A cross-sectional study of the prevalence and associated risk factors for capped hock and the associations with bursitis in weaner, grower and finisher pigs from 93 commercial farms in England

The prevalence of capped hock in 5601 post-weaning pigs from 93 pig farms in England was 17.2%. The prevalence increased with age. Once adjusted for age, the lowest prevalence of capped hock was observed in pigs kept on soil floors (usually covered with deep straw bedding). There was no significant increase in the risk of capped hock in pigs kept on solid concrete floors with deep straw bedding. However, pigs kept on solid concrete with some, or the entire pen, sparsely bedded and pigs kept on partially or fully slatted floors had an approximately threefold increased risk of capped hock. This did not vary significantly between these four floor types. This was in contrast to the associated risks for bursitis in the same pigs, where as the floor went from highly resilient (straw and solid floors) to hard and perforated (fully slatted) the risk of bursitis increased in a similar way to a dose response. No other variables that were measured were associated with a change in risk for capped hock, while observation of pigs slipping or slip marks and wet, dirty and worn pens were also associated risks for bursitis. These results indicate that capped hock and bursitis are both affected by exposure to floors, but in different ways. The prevalence of capped hock was associated only with floor hardness, with deep straw protecting the pigs, while bursitis was associated with both changes in bedding depth (hardness), floor material (soil versus concrete) and floor construction (solid versus slatted floors) and in factors associated with locomotion (slipping and slip marks). These results indicate that the aetiology of capped hock and bursitis might differ.     

Sorghum ergot (Claviceps africana) associated with agalactia and feed refusal in pigs and dairy cattle

OBJECTIVE: To establish the aetiology and define the main clinical features of a syndrome characterised by severe feed refusal, death of piglets and reduced milk production in pigs and dairy cattle. DESIGN: Clinical, pathological, toxicological and epidemiological examination of clinical cases in 10 piggeries and 4 dairies, located between 50 and 150 km south-west of Rockhampton. RESULTS: All cases were associated with the feeding of sorghum grain infected with sorghum ergot (Claviceps africana). There was mild to severe feed refusal when the sorghum was first offered. Sows fed ergot before farrowing had shrunken udders, produced no colostrum, and displayed signs of oestrus. All of their piglets died, apparently from starvation: necropsy of a few piglets showed that they were born alive and walked, but had ingested no milk. Sows fed the grain after farrowing had severe reductions in milk production despite aggressive sucking by piglets, leading to very poor growth of piglets. There were no signs of infectious disease. Ergot in sorghum samples ranged from 1 to 31% ergot sclerotes by weight. Total alkaloid concentrations in mixed feeds ranged from 5 to 40 mg/kg, with dihydroergosine accounting for approximately 90%. At the same time, in the same districts, there were reports of feed refusal and reduced milk production from 4 dairy farms. Grain samples from these farms contained up to 17% C africana ergot sclerotia. CONCLUSION: Agalactia and feed refusal are classical signs of poisoning by rye ergot (C purpurea), but this is the first time that sorghum ergot has been associated with a similar syndrome.