Salmonella immunization confers cross protection without confounding pre-harvest serologic monitoring

Food borne Salmonella Typhimurium is a valid concern for the global pork industry. An attenuated oral swine Salmonella Choleraesuis vaccine has proven to be an effective tool for the pre-harvest reduction of carrier rates for multiple Salmonella spp. Serum antibody assays are available to monitor exposure to wild-type Salmonella infection. This clinical study assessed protection induced by an attenuated oral Salmonella Choleraesuis vaccine against challenge infection with S. Typhimurium in swine. A serologic antibody assay was concurrently evaluated for its ability to differentiate vaccinated pigs from those challenged with Salmonella Typhimurium. Vaccination significantly improved clinical scores, pyrexia, and enteric lesion prevalence, while numerically improving average daily weight gain, and group body weight variation in comparison to unvaccinated/challenged pigs. Vaccination, while protecting pigs against disease, did not generate detectable serum antibodies prior to challenge. No vaccinated animals became seropositive prior to challenge, indicating that conventional ELISA tests could be used in vaccinated pigs to monitor wild-type exposure. Following challenge, there was no detectable difference between vaccinated/challenged and non-vaccinated/challenged animals. All strict control pigs remained serum antibody negative. These findings support the use of this vaccine to protect swine against S. Typhimurium, without confounding pre-harvest Salmonella serologic monitoring programs

Drinking Behavior of Nursery Pigs for Oral Vaccine Administration

Oral vaccination of swine via their drinking water is an increasingly common practice. Improved understanding of swine drinking behavior is needed to ensure immunization of an entire population

Geo-referenced building stock analysis as a basis for local-level energy and climate mitigation strategies

A geo-referenced building stock model was used to analyse the energy and climate performance of the Knowledge Axis in Trondheim, Norway, by 2050. Strategies for energy upgrades, construction of more energy-efficient new constructions, changes in heating technologies, and their implications in terms of energy savings and greenhouse gas (GHG) emissions associated with energy and materials are assessed through various scenarios. Thematic maps were used to display the development of the total floor area and energy use. Compared to the baseline scenario for the same year, the energy savings range from 2 to 9%, 2–14%, and 2–19% in 2030, 2040, and 2050, respectively. New passive house constructions combined with energy upgrades in renovation projects and the maximum use of heat pumps have the greatest energy-saving potential. Our results displayed a large variation in the total net GHG emissions as a result of the alternative emission factors. The total net GHG emissions are primarily affected by the energy savings (amplified by assuming fossil fuel as the marginal mix), electricity mix (Norwegian or European), and allocation chosen for the incinerated waste to feed the district heating system.publishedVersio

Drinker to Nursery Pig Ratio: Preference for a Drinker Location within a Pen and its Effects on Aggression

The objectives of this study were to (1) calculate aggressive interactions around the water bowl drinkers and to (2) determine preference for a water bowl location when pigs were offered either one, two or three water bowl drinkers per pen. Information is available on the current drinker to nursery pig’s ratios (drinker: pigs). In the UK producers are recommended 1:15, while in the US it is 1:10 for nursery pigs. A total of 225 crossbred were seven weeks of age. Conventional nursery pens had plastic flooring and all pigs had ad-libitum access to a commercially formulated diet. Water was delivered through a single stainless steel water bowl drinker and was provided ad libitum. All pigs received a natural light cycle from a curtain sided building. Nine pens were used for behavioral measures. Three treatments were compared. Treatment one (TRT 1; n = 3) was defined as one water bowl drinker per pen. Treatment two (TRT 2; n = 3) was defined as two water bowl drinkers per pen. Treatment three (TRT 3; n = 3) was defined as three water bowl drinkers per pen. One day prior to visual recording of drinking behavior, all pigs in a pen were identified with an individual number. One 12 V black and white CCTV camera was positioned over each water bowl drinker and behavior was recorded from 0700 to 1300 h over two consecutive days onto a DVR at 1 frame per second. The acquisition of drinking behavior (defined as the pig having its head in the water bowl drinker for 5 s or longer) was obtained by three experienced observers who viewed the recordings using 24 h mode (5 frame / s) onto the Observer software. Total number of aggressive interactions and length of aggression around the water bowl drinker over the 6 h period was not (P \u3c 0.05) different between the treatments. The total amount of time that nursery pigs spent when offered two (F vs. O) water bowl drinkers in a pen did not (P = 0.47) differ. However, when pigs were offered three (F vs. O vs. A) water bowl drinkers in a pen there was a difference (P \u3c 0.0001) for total amount of time spent at all three locations. In conclusion, pigs displayed a water bowl drinker preference with the alley location being the least favored; however, there were no difference in the number or length of aggressive interactions

Cost of porcine reproductive and respiratory syndrome virus at individual farm level – An economic disease model

Porcine reproductive and respiratory syndrome (PRRS) is reported to be among the diseases with the highest economic impact in modern pig production worldwide. Yet, the economic impact of the disease at farm level is not well understood as, especially in endemically infected pig herds, losses are often not obvious. It is therefore difficult for farmers and veterinarians to appraise whether control measures such as virus elimination or vaccination will be economically beneficial for their farm. Thus, aim of this study was to develop an epidemiological and economic model to determine the costs of PRRS for an individual pig farm. In a production model that simulates farm outputs, depending on farm type, farrowing rhythm or length of suckling period, an epidemiological model was integrated. In this, the impact of PRRS infection on health and productivity was estimated. Financial losses were calculated in a gross margin analysis and a partial budget analysis based on the changes in health and production parameters assumed for different PRRS disease severities. Data on the effects of endemic infection on reproductive performance, morbidity and mortality, daily weight gain, feed efficiency and treatment costs were obtained from literature and expert opinion. Nine different disease scenarios were calculated, in which a farrow-to-finish farm (1000 sows) was slightly, moderately or severely affected by PRRS, based on changes in health and production parameters, and either in breeding, in nursery and fattening or in all three stages together. Annual losses ranged from a median of € 75′724 (90% confidence interval (C.I.): € 78′885–€ 122′946), if the farm was slightly affected in nursery and fattening, to a median of € 650′090 (90% C.I. € 603′585–€ 698′379), if the farm was severely affected in all stages. Overall losses were slightly higher if breeding was affected than if nursery and fattening were affected. In a herd moderately affected in all stages, median losses in breeding were € 46′021 and € 422′387 in fattening, whereas costs were € 25′435 lower in nursery, compared with a PRRSV-negative farm. The model is a valuable decision-support tool for farmers and veterinarians if a farm is proven to be affected by PRRS (confirmed by laboratory diagnosis). The output can help to understand the need for interventions in case of significant impact on the profitability of their enterprise. The model can support veterinarians in their communication to farmers in cases where costly disease control measures are justified

Modelling the economic efficiency of using different strategies to control Porcine Reproductive & Respiratory Syndrome at herd level

PRRS is among the diseases with the highest economic impact in pig production worldwide. Different strategies have been developed and applied to combat PRRS at farm level. The broad variety of available intervention strategies makes it difficult to decide on the most cost-efficient strategy for a given farm situation, as it depends on many farm-individual factors like disease severity, prices or farm structure. Aim of this study was to create a simulation tool to estimate the cost-efficiency of different control strategies at individual farm level. Baseline is a model that estimates the costs of PRRS, based on changes in health and productivity, in a specific farm setting (e.g. farm type, herd size, type of batch farrowing). The model evaluates different intervention scenarios: depopulation/repopulation (D/R), close & roll-over (C&R), mass vaccination of sows (MS), mass vaccination of sows and vaccination of piglets (MS + piglets), improvements in internal biosecurity (BSM), and combinations of vaccinations with BSM. Data on improvement in health and productivity parameters for each intervention were obtained through literature review and from expert opinions. The economic efficiency of the different strategies was assessed over 5 years through investment appraisals: the resulting expected value (EV) indicated the most cost-effective strategy. Calculations were performed for 5 example scenarios with varying farm type (farrow-to-finish – breeding herd), disease severity (slightly – moderately – severely affected) and PRRSV detection (yes – no). The assumed herd size was 1000 sows with farm and price structure as commonly found in Germany. In a moderately affected (moderate deviations in health and productivity parameters from what could be expected in an average negative herd), unstable farrow-to-finish herd, the most cost-efficient strategies according to their median EV were C&R (€1′126′807) and MS + piglets (€ 1′114′649). In a slightly affected farrow-to-finish herd, no virus detected, the highest median EV was for MS + piglets (€ 721′745) and MS (€ 664′111). Results indicate that the expected benefits of interventions and the most efficient strategy depend on the individual farm situation, e.g. disease severity. The model provides new insights regarding the cost-efficiency of various PRRSV intervention strategies at farm level. It is a valuable tool for farmers and veterinarians to estimate expected economic consequences of an intervention for a specific farm setting and thus enables a better informed decision

Ricci curvature and monotonicity for harmonic functions

Original manuscript September 20, 2012In this paper we generalize the monotonicity formulas of “Colding (Acta Math 209:229–263, 2012)” for manifolds with nonnegative Ricci curvature. Monotone quantities play a key role in analysis and geometry; see, e.g., “Almgren (Preprint)”, “Colding and Minicozzi II (PNAS, 2012)”, “Garofalo and Lin (Indiana Univ Math 35:245–267, 1986)” for applications of monotonicity to uniqueness. Among the applications here is that level sets of Green’s function on open manifolds with nonnegative Ricci curvature are asymptotically umbilic.National Science Foundation (U.S.) (Grant DMS 11040934)National Science Foundation (U.S.) (Grant DMS 1206827)National Science Foundation (U.S.). Focused Research Group (Grant DMS 0854774)National Science Foundation (U.S.). Focused Research Group (Grant DMS 0853501