E. R. Benson

Inactivation of Avian Influenza Virus Using Common Detergents and Chemicals

Abstract Six disinfectant chemicals were tested individually for effectiveness against low pathogenic avian influenza virus (LPAIV) A/H7N2/Chick/MinhMa/04. The tested agents included acetic acid (C2H4O2), citric acid (C6H8O7), calcium hypochlorite (Ca(ClO)2), sodium hypochlorite (NaOCl), a powdered laundry detergent with peroxygen (bleach), and a commercially available iodine/acid disinfectant. Four of the six chemicals, including acetic acid (5%), citric acid (1% and 3%), calcium hypochlorite (750 ppm), and sodium hypochlorite (750 ppm) effectively inactivated LPAIV on hard and nonporous surfaces. The conventional laundry detergent was tested at multiple concentrations and found to be suitable for inactivating LPAIV on hard and nonporous surfaces at 6 g/L. Only citric acid and commercially available iodine/acid disinfectant were found to be effective at inactivating LPAIV on both porous and nonporous surfaces.

Evaluation of EEG based determination of unconsciousness vs. loss of posture in broilers.

Evaluation of the loss of consciousness in poultry is an essential component in evaluating bird welfare under a variety of situations and applications. Many current approaches to evaluating loss of consciousness are qualitative and require observation of the bird. This study outlines a quantitative method for determining the point at which a bird loses consciousness. In this study, commercial broilers were individually anesthetized and the brain activity recorded as the bird became unconscious. A wireless EEG transmitter was surgically implanted and the bird anesthetized after a 24-48 h recovery. Each bird was monitored during treatment with isoflurane anesthesia and EEG data was evaluated using a frequency based approach. The alpha/delta (A/D) ratio and loss of posture (LOP) were used to determine the point at which the birds went unconscious. There was no statistically significant difference between time to unconsciousness as measured by A/D ratio or LOP.

Inactivation of avian influenza virus using four common chemicals and one detergent.

Five disinfectant chemicals were tested individually for effectiveness against low pathogenic avian influenza virus (LPAIV), A/H7N2/Chick/MinhMa/04, on hard, nonporous surfaces. The tested agents included acetic acid, calcium hydroxide, sodium carbonate, sodium hydroxide, and a powdered laundry detergent without bleach. Multiple common chemicals including acetic acid (1 and 3%), sodium hydroxide (2%), and calcium hydroxide (1%) effectively inactivated LPAIV on a metal surface. The laundry detergent without bleach, sodium carbonate (4%), and the lower concentration of sodium hydroxide (1%) were not able to consistently inactivate LPAIV on hard, nonporous surfaces.

Comparison of Water-Based Foam and Inert-Gas Mass Emergency Depopulation Methods

Abstract Current control strategies for avian influenza (AI) and other highly contagious poultry diseases include surveillance, quarantine, depopulation, disposal, and decontamination. Selection of the best method of emergency mass depopulation involves maximizing human health and safety while minimizing disease spread and animal welfare concerns. Proper selection must ensure that the method is compatible with the species, age, housing type, and disposal options. No one single method is appropriate for all situations. Gassing is one of the accepted methods for euthanatizing poultry. Whole-house, partial-house, or containerized gassing procedures are currently used. The use of water-based foam was developed for emergency mass depopulation and was conditionally approved by the United States Department of Agriculture in 2006. Research has been done comparing these different methods; parameters such as time to brain death, consistency of time to brain death, and pretreatment and posttreatment corticosterone stress levels were considered. In Europe, the use of foam with carbon dioxide is preferred over conventional water-based foam. A recent experiment comparing CO2 gas, foam with CO2 gas, and foam without CO2 gas depopulation methods was conducted with the use of electroencephalometry results. Foam was as consistent as CO2 gassing and more consistent than argon-CO2 gassing. There were no statistically significant differences between foam methods.

Evaluation of Foam-Based Mass Depopulation Methodology for Floor-Reared Meat-Type Poultry Operations

Current methods of control for quick spreading, highly contagious poultry diseases, such as avian influenza (AI) or Exotic Newcastle, require large numbers of poultry to be rapidly killed to prevent further spread. On-farm depopulation, rather than conventional slaughter at a processing plant, is preferred to avoid the spread of potentially zoonotic agents. It therefore makes sense to depopulate or euthanize the birds as soon as possible and on site. In these circumstances, the most appropriate technique that minimizes human and animal health concerns should be used. The options for mass depopulation are limited, as reported by the 2000 Report of the AVMA Panel on Euthanasia (AVMA, 2001). While these methods are humane and fairly expedient, these procedures are labor intensive and require a significant number of people be involved in the process. This project explores the use of a carbon dioxide (CO2) enriched fire fighting foam system to perform mass emergency depopulation of poultry. The method utilizes a blanket of high expansion foam enriched with carbon dioxide. In four experimental trials, the method has been shown to provide effective depopulation. The foam with varying concentrations of carbon dioxide was directly compared to a currently industry accepted CO2-polyethylene tent method, which uses overlapping layers of polyethylene to cover birds and then gassing with carbon dioxide. The foam and polyethylene tent methods resulted in death in less than 3 min (CO2-polyethylene 2:08 min, foam with CO2 2:09 min, and foam without CO2 2:54 min). Preliminary results indicate that the fire fighting foam is as effective or more effective than conventional CO2-polyethylene tent method.

Application of In-House Mortality Composting on Viral Inactivity of Newcastle Disease Virus

This paper summarizes the results from 3 simulated in-house catastrophic mortality composting experiments. Experiment 1 evaluated the impact of water-based foam mass depopulation on in-house composting of the carcasses and litter and showed that water-based foam improved windrow temperatures. Experiment 2 evaluated the impact of freezing samples on virus recovery from windrow compost tissue and the choice of tissue for virus sampling within the bird. Experiment 2 documented that freezing the samples had minimal impact on processing and that virus recovery was more consistent among inoculated breast meat than inoculated tracheas. Experiment 3 evaluated the impact of sawdust, straw, and sawdust-straw base layer litter material on in-house mortality composting. All litter materials were able to reach and maintain temperatures in excess of 60 degrees C for multiple days. No viral hemagglutination activity was observed after d 2 during any of the 3 experiments.

Durability of Incandescent, Compact Fluorescent, and Light Emitting Diode Lamps in Poultry Conditions

Lighting impacts the behavior, growth, and reproduction of poultry. Artificial lighting is extensively used in raising commercial poultry. The objective of this project was to determine the reliability, illuminance, and power consumption of alternative low-wattage light bulbs under conditions typical in poultry housing. A lighting test apparatus was used in a poultry house to allow simultaneous accelerated durability testing of up to four replications of three lamp types [one type of incandescent lamp, two different types of compact fluorescent lamps (CFL A and B), and one type of light emitting diode lamp (LED)]. Lamps were cycled from 05:00 to 21:00 for 16 cycles per day of 45-min lamps-on and 15-min lamps-off. All lamps were commercially available, non-agriculture specific lamps. No LED lamps failed during 416 d of testing, while the four incandescent lamp failures occurred at an average of 1968 h, and three of four CFL A lamps failures occurred at an average of 2640 h, and one of four CFL B lamps failed at 3312 h while the remainder of the CFL B lamps were operating at the conclusion of the test. The accelerated testing protocol may have influenced the early failures for some lamp types. Both types of CFL and LED lamps evaluated were more energy efficient than incandescent lamps and showed similar reduced relative energy usage compared to incandescent lamps (CFL A: 28%, CFL B: 30%, and LED 33%). CFL and LED lamps showed illuminance degradation during testing; the LED lamps tested showed the greatest decrease.

I. Evaluation of the impact of alternative light technology on male broiler chicken growth, feed conversion, and allometric characteristics

This study evaluates the impact of light-emitting diode (LED), cold cathode fluorescent (CCFL), and incandescent lamps on broiler performance. Male Ross 708 broilers (n=672) were raised to 6 wk age in 8 black-out modified large colony houses, under identical intermittent lighting conditions using 4 unique types of lamps, which were gradually dimmed throughout the study. Incandescent lamps served as the control; experimental technologies tested included CCFL and 2 different LED lamps. Each technology was tested in duplicate for each of 4 trials (8 replications total per technology) conducted across the course of one year to account for seasonal variance. Live performance for each technology was evaluated using live broiler body weight (BW), weight gain, feed conversion, and mortality. Birds were removed from each house at 7, 14, 35, and 42 d to be humanely euthanized, weighed, and necropsied for allometric tissue sample analysis. Relative to the technologies tested, results indicate that birds raised under incandescent lamps had significantly higher BW by 42 d, compared to birds raised under CCFL lamps, which had poorer BW performance (P=0.03). Birds raised under both LED technologies grew to final BWs similar to those raised under incandescent light, with significant differences in neither feed conversion nor mortality.

Comparison of water-based foam and carbon dioxide gas mass emergency depopulation of White Pekin ducks

The mass depopulation of production birds remains an effective means of controlling fast-moving, highly infectious diseases such as avian influenza and virulent Newcastle disease. Two experiments were performed to compare the physiological responses of White Pekin commercial ducks during foam depopulation and CO(2) gas depopulation. Both experiment 1 (5 to 9 wk of age) and 2 (8 to 14 wk of age) used electroencephalogram, electrocardiogram, and accelerometer to monitor and evaluate the difference in time to unconsciousness, motion cessation, brain death, altered terminal cardiac activity, duration of bradycardia, and elapsed time from onset of bradycardia to onset of unconsciousness between foam and CO(2) gas. Experiment 2 also added a third treatment, foam + atropine injection, to evaluate the effect of suppressing bradycardia. Experiment 1 resulted in significantly shorter times for all 6 physiological points for CO(2) gas compared with foam, whereas experiment 2 found that there were no significant differences between foam and CO(2) gas for these physiological points except brain death, in which CO(2) was significantly faster than foam and duration of bradycardia, which was shorter for CO(2). Experiment 2 also determined there was a significant positive correlation between duration of bradycardia and time to unconsciousness, motion cessation, brain death, and altered terminal cardiac activity. The time to unconsciousness, motion cessation, brain death, and altered terminal cardiac activity was significantly faster for the treatment foam + atropine injection compared with foam. Both experiments showed that bradycardia can occur as a result of either submersion in foam or exposure to CO(2) gas. The duration of bradycardia has a significant impact on the time it takes White Pekin ducks to reach unconsciousness and death during depopulation.

Electroencephalogram-Based Methodology for Determining Unconsciousness During Depopulation

SUMMARY. When an avian influenza or virulent Newcastle disease outbreak occurs within commercial poultry, key steps involved in managing a fast-moving poultry disease can include: education; biosecurity; diagnostics and surveillance; quarantine; elimination of infected poultry through depopulation or culling, disposal, and disinfection; and decreasing host susceptibility. Available mass emergency depopulation procedures include whole-house gassing, partial-house gassing, containerized gassing, and water-based foam. To evaluate potential depopulation methods, it is often necessary to determine the time to the loss of consciousness (LOC) in poultry. Many current approaches to evaluating LOC are qualitative and require visual observation of the birds. This study outlines an electroencephalogram (EEG) frequency domain–based approach for determining the point at which a bird loses consciousness. In this study, commercial broilers were used to develop the methodology, and the methodology was validated with layer hens. In total, 42 data sets from 13 broilers aged 5–10 wk and 12 data sets from four spent hens (age greater than 1 yr) were collected and analyzed. A wireless EEG transmitter was surgically implanted, and each bird was monitored during individual treatment with isoflurane anesthesia. EEG data were evaluated using a frequency-based approach. The alpha /delta (A/D, alpha: 8–12 Hz, delta: 0.5–4 Hz) ratio and loss of posture (LOP) were used to determine the point at which the birds became unconscious. Unconsciousness, regardless of the method of induction, causes suppression in alpha and a rise in the delta frequency component, and this change is used to determine unconsciousness. There was no statistically significant difference between time to unconsciousness as measured by A/D ratio or LOP, and the A/D values were correlated at the times of unconsciousness. The correlation between LOP and A/D ratio indicates that the methodology is appropriate for determining unconsciousness. The A/D ratio approach is suitable for monitoring during anesthesia, during depopulation, and in situations where birds cannot be readily viewed.