Abstract #M140

# M140
Responses of neonatal goats (kids) to different concentrations of carbon dioxide gas.
Isabelle C. Withrock*1, Paul J. Plummer1, Timothy A. Shepherd1, Anna Johnson1, Hongwei Xin1, Johann F. Coetzee1, Suzanne T. Millman1, 1Iowa State University, Ames, IA.

The dairy goat industry faces challenges for kid euthanasia. The methods approved by the AVMA are barbiturate overdose, gunshot, and captive bolt. The disadvantages of these methods range from cost to operator safety. Currently, there is no published research on inhalant euthanasia methods for neonatal ruminants. The objective of this study was to evaluate carbon dioxide (CO2) for kid euthanasia. A preference testing device was custom made to hold 2 connected chambers at static atmospheric concentrations. One chamber maintained ambient conditions, and the other designated CO2 levels (treatment). A total of 7 mixed-breed dairy kids were enrolled in the study. Six males and 1 female were enrolled, and body weights ranged from 3.18 to 4.17 kg. Kids were individually trained for 5 consecutive days to enter the treatment chamber from the ambient chamber to access a milk ration (32oz). During training both chambers were set at ambient air concentrations. Kids were held in the ambient chamber for 5 min, after which the sliding door was opened to provide access to the treatment chamber. Kids were provided 10 min access to the treatment chamber after which they were removed and returned to their home pen. After training, testing began with the treatment chamber set at one of 3 CO2 levels: 10%, 20% or 25%, while the ambient chamber was maintained at 1% CO2. Kids were randomly assigned 10% or 20% as the first treatment and received 25% CO2 last. Kids experienced all 3 CO2 treatments, with a 2-d wash-out (ambient CO2) between tests. Outcomes were collected using continuous sampling, and included latency to enter and exit treatment chamber to measure aversion, loss of muscle control (ataxia), and loss of posture. Five kids (71%) tolerated 10% CO2 for 10 min. One kid left at 8.5 min after consuming his full ration. One kid lost posture at 289 s. At 20 and 25% CO2, a total of 100% of the kids became ataxic, and posture loss ranged from 93 to 215 s. All kids continued to consume milk before and during ataxia and reentered the treatment chamber on wash out days. In conclusion, kids did not display aversion to CO2 and therefore, CO2 has merit for goat euthanasia.

Key Words: carbon dioxide, euthanasia, goat