Slaughter Plant Research Articles

Transportation of Cull Sows-Deterioration of Clinical Condition From Departure and Until Arrival at the Slaughter Plant.

Cull sows may be more vulnerable to transportation compared to other swine categories, as they are typically culled after several production cycles, and hence may be injured or weak. Until now, transportation of sows has received very little scientific attention. We aimed to investigate whether the clinical condition of the sows changed during transportation from commercial Danish farms to slaughter plants, and to initiate identification of potential risk factors for such deterioration. This observational study included 522 sows in 47 batches from 12 farms, varying according to transportation time from farm to slaughter plant. Standardized clinical examinations were conducted on-farm and on the slaughter plant. In addition, data on transportation duration, number and duration of stops, temperature during driving, and during waiting before unloading were collected. The sows' median parity was five (range 1–11) and close to 40% were lactating at the day of transportation. The mean duration of transportation was 232 ± 113 min, and the mean temperature in the trucks was 14.1 ± 5.3°C. Half of the clinical variables recorded before and after transportation changed significantly. Among these were injuries (e.g., superficial skin lesions, totally, P < 0.000; front, P < 0.001; wounds, P < 0.001; gait score, P < 0.001), and measures possibly related to heat stress (e.g. skin elasticity, P < 0.001). Three sows arrived in a condition as legally unfit for transport. The deterioration of the sows' condition was mainly related to transportation factors, such as temperature and duration—often in interaction—as well as duration of stops during the journey and while waiting before unloading. The changes in clinical condition were less dependent on the pre-transportation clinical condition of the sows, such as parity, body condition score and gait score. The results show that the clinical condition of the cull sows deteriorated from farm to slaughter plant, thereby adding data to the debate on fitness for transport of cull sows. The main risk factors were not related to characteristics of the sows, but of the journeys. Future studies should focus on identifying and distinguishing between risk factors in order to develop procedures that allow transportation of cull sows to slaughter without jeopardizing their welfare.

Experimental Seneca Valley virus infection in market-weight gilts

Seneca Valley virus (SVV) is a picornavirus that causes vesicular disease in swine. Since it is clinically indistinguishable from vesicular disease caused by food-and-mouth disease virus (FMDV), investigations must be performed to rule out this high consequence pathogen. A large portion of these investigations have involved market-weight swine at slaughter plants. The objective of this study was to describe acute infection dynamics of market-weight gilts (8 months of age) experimentally infected with SVV. At 0 days post inoculation (dpi) all gilts (n=15) were given an intranasal SVV inoculation. Vesicular lesions on the coronary band were first observed on one or more feet by 2 dpi in 4 of the 15 gilts and in all by 5 dpi. Vesicles on the snout were observed in 6 of the 15 gilts beginning at 4 dpi. All gilts became viremic post challenge for about 7 days and developed anti-SVV neutralizing antibodies by 7 dpi. Most vesicular lesions were resolved by 14 dpi. Understanding the pathogenesis of SVV is critical in order to inform decisions that veterinarians and producers must make at the farm level to control this disease.

Short Communication: Field observation: Pen stocking capacities for overnight lairage of finished steers and heifers at a commercial slaughter facility

ABSTRACT The US Humane Slaughter Act requires that cattle held overnight in the lairage have sufficient space to lie down simultaneously. Cattle arriving at the slaughter plant weigh 12% more than finished cattle from the year 2000. The purpose of this observational study was to determine whether industry guidelines for space in overnight lairage are still adequate. A video camera mounted on an overhead catwalk was used to photograph Bos taurus finished cattle in lairage at a large commercial fed beef slaughter plant. The photos were taken at night to determine the space required for all cattle to lie down simultaneously. When the environment is quiet at night, between 0200 to 0400 h, over 90% of the cattle lie down. The following space requirements for cattle of different weights were identified: a 635.03-kg (1,400-lb) animal requires 2.04 m2 (22.0 ft2), which was not accounted for in previous estimates. Space recommendations in lairage need to be increased.

Culling Decisions and Dairy Cattle Welfare During Transport to Slaughter in the United States.

Nearly a third of dairy cows are removed from herds annually in the United States. Our objective is to describe what is known about the process of sending a dairy cow to slaughter in the United States including our perspectives about her fitness for transport, her condition upon arrival at the slaughter plant and the decisions to transport her in the first place. This process begins when the decision is made by the farmer to remove a cow from the herd. Once a cow leaves the farm, she makes her way either directly to slaughter or goes through one or more livestock auctions or markets along the way. Cull cows can travel considerable distance to slaughter and may face a number of welfare challenges during this process. These stressors are exacerbated if the cows are compromised and not fit for transport. While all major industry stakeholders have recommendations or guidelines about fitness for transport, none are enforced rules or regulations. There is little financial disincentive for farmers to stop shipping compromised dairy cows, and, in some cases, slaughter plants are willing to take the risk on purchasing cows in this condition as those that survive the journey often generate a good margin of return. As a result, the decision to ship compromised cull cows is too common, as indicated by data about cow condition both at the farm and the slaughter plant. Compromised culled dairy cattle continue to arrive at slaughter plants and leadership within the industry is needed to tackle this welfare challenge.

Infrared Thermography for the Ante Mortem Detection of Bruising in Horses Following Transport to a Slaughter Plant.

Undetected injury of horses sustained during road transport to slaughter is a welfare concern. This study evaluated digital infrared thermography (DT) for the detection of ante-mortem bruising in horses following transport to a slaughter plant. The sensitivity and specificity of DT for the detection of bruises following transport was evaluated. DT images were obtained from 93 horses (2–3 horses per load; 40 loads) at a Canadian federally approved slaughter plant. From an elevated platform 5 m from the horses, left and right lateral DT images, and one caudal pelvic area image were obtained from each horse. After slaughter the carcasses were examined for bruising (a visually discolored area on the carcass caused by damage to the blood vessels) and findings documented. Sensitivity, specificity, and predictive values were calculated for DT assessment of bruising. The prevalence of bruising on post mortem inspection was 54%. The DT approach to bruise detection at the region of interest level of 93 horses (n = 186 sides) resulted in a sensitivity of 42% and specificity of 79%. As the sensitivity was low, a more sensitive DT camera and allowing for a longer equilibration time for horses after transport may improve this approach to post transport assessment of subclinical injury.

Use of radio telemetry to determine presence of cattle stress indicators before slaughter

This study was conducted in order to determine the presence of stress in cattle prior to slaughter in situations such as loading, trans-porting, unloading, water and food deprivation during mobilization and waiting in the corral in overcrowded and inclement condi-tions. Samples were five bovines with ages of 40 months on average, castrated males, from the San Martinero criolla breed, whichwere transported along 144 Km, by land, from the farm located in Acacias, department of Meta, to the ICTA slaughter plant in Bo-gotá. The stress indicators were identified by differences in body temperature, heart rate and respiration frequency (hereinafter-physiological constants), which were monitored for 20 minutes at the time: prior to loading the animals on the farm, and uponarri-val at the slaughterhouse (just after being transported). The bovine cardiac signal was captured and processed through a girth, and was transmitted via a radio telemetry system that was designed and built in the project. The results show data capture at a sample rate of four million samples per second and wireless communication in real time, which meant that no information was lost on thevariations of the bovine heart signal and reception of information from any point of the slaughter plant.

Comparison of Lipid and Protein Oxidation Products and their Impact on Colour Stability in Bison Longissimus Lumborum and Psoas Major Muscles

ObjectivesTo compare lipid (malondialdehyde [MDA], 4-hydroxy-2-nonenal [HNE]) and protein (carbonyl content [CAR]) oxidation products and determine their influence on color stability in two bison muscles (longissimus lumborum [LL; color stable] and psoas major [PM; color labile]).Materials and MethodsA total of 10 longissimus lumborun (LL) and 10 psoas major (PM) from five A1 grade bison carcasses were obtained from a commercial slaughter plant within 48 h post-mortem. From each muscle, a 10-cm thick piece was removed and subsampled for evaluation of pH, MDA (by thiobarbituric acid assay), HNE (by ELISA) and CAR (by 2,4-dinitrophenylhydrazine). These measurements allowed the establishment of a baseline for the different oxidation products. The remainder of the muscles were cut into two equal portions, and each portion was vacuum-packaged and assigned to an ageing period of 7 and 14 d at 2°C. At the end of each ageing period, each muscle portion was removed from their packages, pH measured, and steaks obtained for sensory (muscle and discoloration scores) and instrumental color measurements (L*, a* and b*) over 5 d of retail display, and for estimation of MDA, HNE and CAR. After 5 d in retail display and following color and pH measurements the steaks were removed and collected for MDA, HNE and CAR determination. Data were analyzed as a completely randomized design with a split-split plot arrangement. Additionally, correlation and regression analysis were performed to identify the influence of the measured attributes on color.ResultsRegardless of the ageing time, LL showed greater redness and lower surface discoloration by instrumental (a* value; P = 0.04) and sensory (P < 0.01) color evaluation than PM at the end of the retail display. Furthermore, LL exhibited lower MDA, HNE and CAR content compared to PM (P < 0.05). A three-way interaction (muscle × ageing time × retail day display) was detected on MDA content, where PM presented a higher level of MDA with increasing ageing time and retail display than LL (P = 0.02). The pH was not different between LL and PM (P > 0.05) steaks.In both muscles, Pearson (r) and Spearman (rs) correlation coefficients indicated that MDA was the oxidation compound showing the highest correlation to a* (r = –0.78; P < 0.01) and discoloration (rs = 0.81; P < 0.01) scores, followed by a moderate correlation with HNE and CAR (r or rs < 0.7; P < 0.01). The pH did not exhibit correlation with color traits, except for lightness, in both muscles. For the stepwise regression analysis, the main variable entered into the equation for predicting a*, color and discoloration score in PM muscle was MDA with an R2 of 0.72, 0.75 and 0.78, respectively, while for LL muscle, MDA presented an R2 of 0.62, 0.68 and 0.66;, respectively. The pH, HNE and CAR only explained an additional 2% of the variation in those attributes.ConclusionThe results of color attributes corroborated that bison LL is a color-stable muscle due to the lower level of protein and lipid oxidation products developed during storage and retail display compared to PM muscle, which is considered color-labile muscle. The MDA seemed to have remarkable importance in the color deterioration than HNE and CAR, particularly in bison PM muscle.

An evaluation of environmental, intrinsic and pre- and post-slaughter risk factors associated to dark-cutting beef in a Federal Inspected Type slaughter plant

The objective was to determine the risk factors associated to dark-cutting in bovine carcasses. The study was conducted at a Federal Inspection abattoir located in northeastern Mexico. A random sample of 394 animals at slaughter was used. A total of 26 explanatory variables were evaluated; the analysis included environmental, animal-specific, and management factors both at pre- and post- slaughter periods. Only four variables were statistically significant within the final logistic regression model (P < .001). The frequency of dark-cutting carcasses was 13.45%. Lairage time was directly proportional to the percentage of risk for dark-cutting beef. Improper desensitization also increased the frequency of carcasses with this anomaly. Backfat thickness and the 24-h pH differential of the carcasses were inversely proportional to the risk for dark-cutting beef. An interesting finding was that risk factors for DFD meat are present in all stages of the slaughter process and thus to effectively address this problem an integral evaluation is needed throughout the slaughter process.

Exploration of methods for lamb carcass yield estimation in Canada

Different approaches were evaluated to improve the accuracy of carcass yield predictions of Canadian lamb carcasses using manually obtained measurements and dual-energy X-ray absorptiometry (DEXA). Several linear carcass measurements were obtained from a population of commercial lamb carcasses representative of the variability in Canadian slaughter plants (n = 155). Carcass measures were categorized into four sets according to when each measure could be obtained in the slaughter process. Each set of carcass measurements were subjected to stepwise regression and used to develop models for the estimation of lean meat and saleable yield percentages. Tissue depth measures (at the GR site) explained 44% of variation in lean meat yield in hot carcasses and 53% in cold carcasses. When additional parameters were included with cold GR, the regression model explained 61.9% of the variability in lean meat yield. Saleable yield predictions were less accurate (R2 &lt; 0.40); the greatest degree of variability was predicted when the model included ribeye area (R2 = 0.39). The DEXA scans obtained on carcass sides were able to predict about 78% of variability in carcass lean meat yield and 91% of fat content. This information could be used by the lamb meat industry to establish new carcass classification systems based on more accurate lean meat yield values.

Risk Factors for Deterioration of the Clinical Condition of Cull Dairy Cows During Transport to Slaughter.

Cull dairy cows are typically transported to slaughter by road. Across different types of cattle, road transport is recognized as stressful. Cull dairy cows may have different injuries or weaknesses and may thus be more vulnerable to transport stress than other types of cattle. The aim of this study was to investigate whether the clinical condition of cull dairy cows deteriorates during transport (< 8 h), and to evaluate risk factors for potential deterioration of the clinical condition. A total of 411 dairy cows were clinically examined on farm before loading and again after unloading at the slaughter plant. The clinical examination included locomotion, presence of wounds, milk leakage, and general condition. One-fifth of the cows either became lame or more lame during transport, and there was a significant increase in the proportion of lame cows after transport (41% after vs. 31% before, P < 0.0001). A significant increase in the proportion of cows with milk leakage (17% vs. 1%, P < 0.0001) and wounds (34% after vs. 22% before, P < 0.0001) after transport were also found. Low body condition score (BCS) (< 2.75) (P = 0.001), early or late lactation [< 100 days in milk (DIM) or >300 DIM] (P = 0.01), digital dermatitis in the hind feet (P = 0.01), and pelvic asymmetry (P = 0.001) were identified as risk factors for the deterioration in lameness during transport. Early lactation (< 100 DIM) (P = 0.04) and transport distance (>100 km) (P = 0.006) were identified as risk factors for milk leakage. For wounds, no significant risk factors were found. The results demonstrate that cull dairy cows are vulnerable to the strains of transport, even journeys shorter than 8 h, to the extent that the occurrence of clinical findings were increased after transport in cows legally considered fit for transport. These results call for further research into the animal welfare implications and optimization of cattle transport.

Describing the cull sow market network in the US: A pilot project

Currently, little objective data is available describing the movements of cull sows and cull pigs through market channels or the association these movements with disease transmission risk. In this pilot study, we collected data to describe the scope and complexity of movements within the sow market channel. Premise ID tags where collected from all animals moving through a single slaughter plant over a one-week period in 2017. The premise ID’s were each cross referenced with a public database to obtain origin location, and each tag was matched with its final collection point (FCP). This allowed terminal market, FCP, and point of origin of each sow to be determined. Approximately 90.4% of all sows moving to the plant during the one-week period were identified, indicating the utility of this data collection approach. Sows originated from premises in 21 states and Canada, and shipped from collection points in 7 states and Canada. Sows traveled a median straight-line distance of 1057 km, identifying the national scope of the sow market. Of the sows identified, 86% entered the plant from a final shipping point that was within 240 km to the source farm. The remaining 14% traveled more than 240 km from the premise of origin to the final point of shipment with 2.5% traveling distances 5 times greater between premise and FCP, then from FCP to the plant. From this it was hypothesized that not only is the sow market national in scope, but a significant number of sows are moved between multiple collection points prior to arriving at the terminal market. The combination of these two factors makes the sow network a likely candidate of pathogen transmission throughout the swine industry.

Surveillance of avian influenza virus in poultry environment in Henan Province, 2013-2017

Objective To monitor the environmental contamination with avian influenza virus (AIV) in Henan Province. Methods Environmental samples were collected every month from seven monitoring sites in Henan from 2013 to 2017. Real-time RT-PCR method was performed to detect the nucleic acid of influenza A (Flu A), H5, H7 and H9 viruses in poultry environmental samples. Results A total of 2 538 environmental samples were collected and 202 (7.96%) of them were positive for Flu A nucleic acid, including 16 positive for H5 (0.63%), eight positive for H7 (0.32%) and 161 positive for H9 (6.34%). The detection rate of Flu A increased dramatically from 2013 to 2017 except for a small fluctuation in 2015. However, H7 subtype AIV was detected only in 2015 and 2017. The highest detection rate of AIV was in February, followed by that in January. Among different environments, the highest detection rate of Flu A was in live poultry market, which was 13.69%, followed by that in poultry slaughtering plant (2.58%) and poultry farm (0.58%). The detection rates of Flu A in swab samples of poultry plucker and cutting board, stool specimens and poultry drinking water were 28.57%, 13.76%, 5.70% and 5.26%, respectively. Conclusion Contamination of H5/H7/H9 AIV did exist in poultry environment in Henan and was getting worse. Increasingly diversified sources and sale channels were the main causes of serious contamination of AIV. In order to effectively prevent and control human infection with AIV, live poultry in areas where human infection with AIV was confirmed should be blocked and banned to be sold to others areas. Key words: Avian influenza; H5/H7/H9 subtypes; Surveillance

Determinants of Breeding Farmers' Safe Use of Veterinary Drugs: A Theoretical and Empirical Analysis.

As food safety has attracted the widespread attention of society, the quality safety of agricultural products has become an important part of food safety and also confronts multiple challenges. In fact, the safe use of veterinary drugs in the production process has become one of important guarantees for the quality safety of agricultural products. It’s of great significance to regulate the breeding farmers’ safe use of veterinary drugs and to create a safe and healthy production environment for agricultural products. A field survey of individual and large-scale swine breeding farmers in four typical provinces including Henan, Shandong, Jiangxi and Guizhou generated 397 questionnaires. This field survey conducted the internal and external classification of breeding farmers’ safe use of veterinary drugs and defined the breeding farmers’ safe use of veterinary drugs in the light of dosage, type and standardized operation of veterinary drugs. Based on Lewin’s behavior theory, the survey used the structural equation modeling method to systematically examine the generation path of breeding farmers’ safe use of veterinary drugs. The comprehensive analysis reveals that breeding farmers’ knowledge about veterinary drugs, the attitudes toward the government supervision and the market environment of breeding activities all exert some effects on breeding farmers’ use of veterinary drugs. Some suggestions and countermeasures for breeding farmers’ safe use of veterinary drugs are provided as follows: First, more efforts should be pumped into publicity and instruction so that breeding farmers can have a better understanding of veterinary drugs. Second, preferential policies should be formulated to encourage the breeding farmers’ participation in the industrial organizations of swine breeding farmers, and advocate the industrial organizations’ active provision of different technical trainings. Third, the communication and cooperation platform should be created among breeding farmers, slaughter and processing plants and supermarkets, the poultry insurance market should be regulated, and the insurance purchase process should be improved. Fourth, when more subsidies for harm-free and environment-friendly veterinary drugs are provided, more serious punishments should be imposed on the unsafe use of veterinary drugs to offer policy support for the breeding farmers’ standardized use of veterinary drugs.

Hot topic: Management of cull dairy cows—Consensus of an expert consultation in Canada

Many cull dairy cows enter the marketing system and travel to widely dispersed and specialized slaughter plants, and they may experience multiple handling events (e.g., loading, unloading, mixing), change of ownership among dealers, and feed and water deprivation during transport and at livestock markets. The objectives of this study were to describe the diverse management of cull dairy cows in Canada and establish consensus on ways to achieve improvements. A 2-day expert consultation meeting was convened, involving farmers, veterinarians, regulators, and experts in animal transport, livestock auction, and slaughter. The 15 participants, recruited from across Canada, discussed regional management practices for cull cattle, related risk factors, animal welfare problems, and recommendations. An audio recording of the meeting was used to extract descriptive data on cull cattle management and identify points of agreement. Eight consensus points were reached: (1) to assemble information on travel times and delays from farm to slaughter; (2) to increase awareness among producers and herd veterinarians of potential travel distances and delays; (3) to promote pro-active culling; (4) to improve the ability of personnel to assess animal condition before loading; (5) to identify local options for slaughter of cull dairy cows; (6) to investigate different management options such as emergency slaughter and mobile slaughter; (7) to ensure that all farms and auctions have, or can access, personnel trained and equipped for euthanasia; and (8) to promote cooperation among enforcement agencies and wider adoption of beneficial regulatory options.

The outbreak that changed meat and poultry inspection systems worldwide.

In the course of history, one of the best recognized constants is that change happens most often and most rapidly in response to a dire situation. Even when efforts to introduce improvements have been ongoing for quite a while, it is not until an emergency or a crisis develops that people are ready to accept change to resolve the problem at hand. Such has been the case with meat and poultry safety. Many in the community, whether regulators, the industry, researchers, or advocates would agree that the most significant and impactful such event was the 1993 outbreak of foodborne illness associated with the Jack-in-the-Box restaurant chain. According to the Washington Department of Health (WDOH), where the outbreak was first reported, a cluster of children were suffering from hemolytic uremic syndrome (HUS) caused by infection with Escherichia coli O157:H7, a little-known bacterial pathogen (CDC, 1993). The investigation quickly determined that the regular-sized hamburger patties and jumbo patties produced by Vons’ Companies of California and sold to the public by Jack-in-the Box were the source of the organism. The outbreak resulted in more than 600 illnesses with four children dead from having consumed undercooked hamburgers. To say that this was a scandal is an understatement. This situation was so dire that the outbreak was discussed as an agenda item during President Bill Clinton’s first cabinet meeting in 1993, after his inauguration as the 42nd President of the United States (Cross, Personal Communication, 2018). Many things changed following that meeting, culminating in a regulatory mandate by USDA’s Food Safety & Inspection Service (FSIS) for industry to implement the Hazard Analysis and Critical Control Point (HACCP) system at every federally inspected meat and poultry slaughter and processing plant in the United States. However, it may come as a surprise to some that the foundation for changes in food safety processes had already been in the works the year preceding the outbreak. A review of the events that took place in 1992 and how those activities had a direct impact on the events to come is justified.

Effect of health status evaluated at arrival on growth in milk-fed veal calves: A prospective single cohort study

The objective of this prospective single cohort study was to determine the effect of health status at arrival on growth in milk-fed veal calves. Upon arrival at the veal facility, calves were evaluated using a standardized health scoring system and weighed, and the supplier of the calf was recorded. The calves were followed until slaughter, when the hot carcass weight (HCW) was reported. To calculate average daily gain (ADG), the HCW was transformed into an estimated live weight, weight at arrival was subtracted, and this value was divided by the number of days on feed. A mixed linear regression model was created to evaluate the association of health status on arrival with the ADG throughout the production period. A total of 4,825 calves were evaluated at arrival; however, due to inconsistent HCW data from one slaughter plant, and 357 calves dying during the production period, 2,283 calves were used for analysis. In the final model, 7 variables were significantly associated with ADG. Housing location within the farm, method of calf procurement (drover or auction-derived calves versus direct delivery from local farms) and having a higher body weight at arrival were associated with a higher ADG. The season of arrival (summer or fall compared with winter) and being dehydrated at arrival were associated with a lower ADG. Days on feed was also significant in the multivariable model and had a quadratic relationship with ADG. The associations identified suggest that there may be value in scoring dehydration and body weight at arrival to a veal facility.

Application of a ventilation fan-misting bank on pigs kept in a stationary trailer before unloading: Effects on trailer microclimate, and pig behaviour and physiological response

The aim of this study was to evaluate the effectiveness of water misting with forced ventilation on a stationary trailer on internal vehicle ambient conditions, and behavioural and physiological response of market pigs. During 6 shipments, two identical 2-axle pot-belly trailers transported 191 pigs each (126 ± 5 kg BW) to the same slaughter plant (135 km). On arrival, trailers were kept stationary in the yard for 30 min before unloading. One trailer was positioned along a fan-misting bank (PBVM), while the other trailer had no access to this cooling system (PBC). The PBVM treatment consisted of 10 min of fan-assisted ventilation (phase 1, P1) followed by 10 min of ventilation and water misting (phase 2, P2) and a final 10 min of ventilation (phase 3, P3). Within each trailer, 4 compartments (rear-top [C4], front-middle [C5], center-middle [C7], and front-bottom [C9]) were chosen for data collection. The air temperature (T) and relative humidity (RH) were monitored using data loggers. The percentage of lying pigs during each phase, and the latency to lie down and the frequency of drinking during lairage were calculated. Gastrointestinal tract temperature (GTT) and exsanguination blood lactate, hematocrit, creatine kinase and cortisol concentrations were assessed. Data from the last 5 min of P1 (wait 1), P2 (wait 2), and P3 (wait 3) were analysed. In wait 1, the application of the fan-assisted ventilation resulted in lower (P ≤ 0.05) T and temperature-humidity index (THI) in the PBVM compared to the PBC. A greater (P ≤ 0.05) drop in RH was recorded in C5 and C7 of the PBVM compared to the same compartments in the PBC. In wait 3, T and THI were lower (P < 0.001) in PBVM compared to PBC, but the RH was higher (P < 0.01). Pigs from C4 in the PBVM had a greater (P < 0.001) activity during phases 2 and 3, and a reduced latency to lie down in the lairage pen compared to the same compartment in the PBC (P ≤ 0.05). A higher (P ≤ 0.05) GTT drop was recorded until 1 h after lairage in pigs located in PBC compared to those transported in PBVM. Although the efficiency of the fan-misting bank varied by compartment location, this cooling system appears to be effective in improving the trailer internal thermal environment and thermal comfort of pigs kept in a stationary trailer.

Characterization and optimization of a heterotrophic bacterium for sulfide degradation

The emission of hydrogen sulfide in the waste gas from slaughter plant, fishmeal feed processing and some other food industrial processing could cause serious air pollution to the surrounding environment. The purpose of this study was to screen heterotrophic bacterium strains for the removal of hydrogen sulfide odor. One heterotrophic bacterial mutant ZJNB-B3 was derived from the sulfide degrader Bacillus cereus XJ-2 and its sulfide removal efficiency was 97%. Based on the morphology studies, biochemical tests and 16S rRNA gene analysis, the strain was identified as Bacillus cereus ZJNB-B3. The NCBI GenBank accession number is MF679650. Batch tests showed that the strain tolerated up to 300 mg/L of toxic S²⁻ concentration. Response surface methodology was applied to optimize the conditions of degradation of sulfide. The optimal parameters were as follows: initial sulfide concentration 211.8 mg/L, initial pH 6.72, inoculum volume 5.04%, and incubation temperature 30 ℃. The accumulated sulfate concentration was 63.8 mg/L and the sulfide removal efficiency was 97.3% after 48 h incubation. No sulfuric acid was generated during sulfide oxidation by the strain. Sulfide could be removed effectively by this strain under mild pH conditions. The results suggested that the strain may have great industrial application potential. This study provides the fundamentals for the removal of hydrogen sulfide gas.

First approach validating a scoring system for foot-pad dermatitis in broiler chickens developed for application in practice

Measuring the severity of foot-pad dermatitis is an accepted tool monitoring the quality of animal husbandry and welfare. Up to now, a variety of scoring schemes have been used, most of them based on visual evaluation. However, a standardisation and validation of scoring systems is beneficial, not only to compare different studies, but to provide objective indicators in poultry welfare. In this study, we validated one visual scoring system, widely used in Northern Germany, by using additional information of histological measurements. Therefore, feet of broiler chickens (ROSS 308) from one flock were visually scored at the slaughter plant (4-point score). Ten feet per score level (n = 40) were sampled and analysed macroscopically and microscopically. Data were analysed using cluster analysis, providing a classification based on these histopathological findings. Validity of the visual scoring system was analysed by (1) testing the interobserver reliability between different observers and (2) by comparing both, visual and cluster classification types using the McNemar’s test. In a last step Kendall tau correlations were calculated in order to find suitable parameters to judge the severity in a visual score more reliably. Results could show that most agreement was found for the score levels 1 and 2, whereas results for score levels 3 and 4 were more divergent. These results were found in both, interobserver reliability and comparison of classification types (visual vs. cluster). Results revealed interaction effects of classification type and scoring level for the width of ulcers (p = 0.0044) and the size of the lesion (p = 0.0081). In the cluster classification, higher values in both, width of ulcer and size of lesion could be found in score level 3. Furthermore, a positive correlation of the size of lesion with the depth of the ulcer was found (0.73). In conclusion, we found that histological findings coincided well with the less severe visual scores (1; 2), whereas the differentiation between the severe scores (3; 4) seemed to be less valid. For practical purposes we therefore recommend keeping visual scoring systems simple. Furthermore, as the correlation coefficient between both was quite high, the size of the lesion might serve as an indirect indicator of the depth.

Using an agent-based model to evaluate the effect of producer specialization on the epidemiological resilience of livestock production networks.

An agent-based computer model that builds representative regional U.S. hog production networks was developed and employed to assess the potential impact of the ongoing trend towards increased producer specialization upon network-level resilience to catastrophic disease outbreaks. Empirical analyses suggest that the spatial distribution and connectivity patterns of contact networks often predict epidemic spreading dynamics. Our model heuristically generates realistic systems composed of hog producer, feed mill, and slaughter plant agents. Network edges are added during each run as agents exchange livestock and feed. The heuristics governing agents’ contact patterns account for factors including their industry roles, physical proximities, and the age of their livestock. In each run, an infection is introduced, and may spread according to probabilities associated with the various modes of contact. For each of three treatments—defined by one-phase, two-phase, and three-phase production systems—a parameter variation experiment examines the impact of the spatial density of producer agents in the system upon the length and size of disease outbreaks. Resulting data show phase transitions whereby, above some density threshold, systemic outbreaks become possible, echoing findings from percolation theory. Data analysis reveals that multi-phase production systems are vulnerable to catastrophic outbreaks at lower spatial densities, have more abrupt percolation transitions, and are characterized by less-predictable outbreak scales and durations. Key differences in network-level metrics shed light on these results, suggesting that the absence of potentially-bridging producer–producer edges may be largely responsible for the superior disease resilience of single-phase “farrow to finish” production systems.