BACKGROUND
current developments in public opinion and politics
germany has one of the strictest animal welfare laws worldwide.
there is no other country in the european union , which integrated animal welfare into its constitution – in germany animal welfare was made a national objective already in  <dig>  <cit> .
in recent years the slaughter of pregnant cattle has gained importance in the public debate on animal welfare.
due to scientific work by, amongst others, peisker et al., riehn et al., di nicolo, lücker et al.
, a political and scientific debate has emerged about whether the slaughter of pregnant animals can be reconciled with the requirements for a humane killing of animals.
one of the major ethical concerns in this context is the perceptual awareness and viability of foetuses during the slaughter of the mother.
marahrens and schwarzlose of germany’s federal research institute for animal health promote the opinion that foetuses in the 3rd trimester will have a relevant reduced welfare during the slaughter of their mother  <cit> .
the authors state, that more research is needed to assess the observed changes in physiological, electrophysiological, and endocrinological parameters of the foetuses that are exposed to such a treatment.
in march  <dig> public interest was attracted by a television report that addressed the suffering of foetuses during slaughter  <cit> .
the increased media interest on animal welfare issues related to slaughter in germany and abroad has caused german politicians to focus on these topics.
the on-going dialogue led to a request in the course of the standing committee on the food chain and animal health meeting in brussels, april 8th  <dig>  <cit> .
in response to this, a mandate was given to the european food safety administration  by the european commission in order to investigate the scope of this problem and develop possible solutions.
additionally, if needed, the council regulation  no 1099/ <dig> on the protection of animals at the time of slaughter should be reviewed with respect to protection of the unborn life  <cit> .
appearance of the problem
the slaughter of pregnant cattle was considered negligible by the scientific committee on veterinary measures relating to public health in  <dig> .
according to the scvph “meat consumption from pregnant heifers is exceptional as usually these animals are not slaughtered”  <cit> .
some studies, however, have since contradicted these assumptions and demonstrated that the actual numbers are much higher.
table  <dig> gives an overview of study results for the prevalence of slaughter of gravid cattle in germany and some other countries .
prevalence in german abattoirs ranges from  <dig>  %  up to 15 %  <cit> .
in luxembourg, belgium and italy the proportion of pregnant animals is  <dig>  %,  <dig>  %, and  <dig>  % respectively  <cit> .
in two british abattoirs, singleton and dobson observed that  <dig>  % of the cows were pregnant  <cit> .
as depicted in table  <dig>  most of the cows were in the 2nd and 3rd trimester at the time of slaughter .
the fact, that hardly cows in the 1st trimester were observed may be attributed to the circumstance that early pregnancies may be overlooked on both farm and abattoir level.
generally, the data from the different studies should be interpreted with care, as different study designs may impede their comparability.table  <dig> prevalence of slaughtering gravid cows in germany and other countries – results of different authors
different authors described the prevalence of slaughtering gravid cows and their stage of gravidity in germany and some other countries.
however, the problem cannot be underestimated in its significance, since not only cattle but also other species are effected as demonstrated by fayemi and muchenje  <cit> .
legal and ethical aspects
there are no regulations, neither in national nor in community law, prohibiting the slaughter of pregnant animals and governing the fate of the foetuses.
due to a supposed underestimation of the total prevalence by the scvph and the lack of reliable data legislators at european level have not issued any mandatory regulations on how to handle the problem  <cit> .
in addition, no options are granted to the member states to adopt any regulations with regard to this issue at national level.
currently the only statute protecting females around the time of calving is the eu transport regulation – regulation  1/ <dig> annex i, chapter i nr.
<dig> c  <cit> .
it prohibits the transport of “pregnant females for whom 90 % or more of the expected gestation period has already passed, or females who have given birth in the previous week”.
riehn et al.
<cit>  indicate that determining the correct percentage of gestation is almost impossible on abattoir level, where only limited examination opportunities are available during pre-mortem inspection.
the authors also state, that the regulation  854/ <dig>  <cit>  obliges the official veterinarian nevertheless to do a pre-mortem inspection  “to verify compliance with relevant community and national rules on animal welfare, such as rules concerning the protection of animals at the time of slaughter and during transport” .
the fate of foetuses is also not specifically mentioned in any regulation.
however, chapter ii, article  <dig> of the regulation  1099/ <dig>  <cit>  states that “animals shall be spared any avoidable pain, distress or suffering during their killing and related operations“ and that “business operators shall, in particular, take the necessary measures to ensure that animals  are provided with physical comfort and protection” and  “do not show signs of avoidable pain or fear or exhibit abnormal behaviour“.
to date there is a dispute if and from which developmental stage on foetuses are conscious and sensitive to stress.
former studies, especially by mellor et al.
assume that foetuses lack such abilities.
this opinion may be reviewed in the light of new scientific evidence.
bellieni and buonocore  <cit>  report that foetuses are able to feel stress and pain from the second half of the gestation on.
the experimental animals directive 2010/63/eu revising directive 86/609/eec on the protection of animals used for scientific purposes  <cit>  already considers these new research results and states in recital  <dig> that “ there is scientific evidence showing that such  in the last third of the period of their development are at an increased risk of experiencing pain, suffering and distress, .” altogether, it cannot be ruled out that foetuses feel pain, distress and other forms of suffering and therefore the slaughter of pregnant cattle in advanced gestational stages should be considered as an animal welfare problem.
the reasons on farm level for slaughtering gravid cows can only be assumed in the absence of valid data.
the federal association of veterinary officers germany presumes the following reasons : slaughter by mistake with unknown pregnancy; injured animals, which cannot be used any more; economic reasons  <cit> .
the relevance of economic aspects in this context is stressed by many authors e.g.
riehn et al., cordes, münch and richter, tierärztliche vereinigung für tierschutz e.v.
<cit> .
objective
considering the heterogeneous data and study designs of previous german studies while respecting their relevance for further political development, our objectives were to i) determine the prevalence of the slaughter of pregnant cattle in germany semi-quantitatively and ii) to investigate the occurring gestational stages and fate of the foetuses.
methods
survey design and questionnaire
for this investigation, an observational, cross-sectional study design was used.
a voluntary and anonymous survey with specific questions was conducted amongst all final-year-students of the faculty of veterinary medicine of the university of leipzig from january  <dig> until september  <dig>
in germany the study of veterinary medicine is regulated by the “verordnung zur approbation von tierärztinnen und tierärzten” .
the regulation stipulates that every student has to absolve a slaughterhouse-internship of at least 100 hours in three weeks under the supervision of the local competent authority.
in the course of the internship, students are required to learn and practice the ante- and post-mortem inspection of cattle and pigs, taking particular care of animal welfare.
our study is therefore aimed at the observations of the veterinary trainees during their meat hygiene internship.
general information and preparation for the internship was conducted during a short obligatory briefing as part of the meat hygiene lecture.
in addition to the general organizational information, students were asked to pay attention to specific aspects such as the slaughter of pregnant cattle and write a voluntary, anonymous internship report.
from january  <dig> until september  <dig> following their final exam in meat hygiene, all students of the faculty of veterinary medicine of the university of leipzig were asked to participate in a survey.
participation was voluntary, anonymous, and had no influence on exam results.
the survey consisted of two questionnaires– one for cattle and one for pigs – each containing five groups of questions about ante- and post-mortem inspection and animal welfare.
for each species and abattoir the students were asked to indicate the date and abattoir of their internships.
one set of questions addressed the prevalence of the slaughter of female cattle and the frequency of pregnancy amongst the cows and heifers including their stage of gestation as recognized by the students.
additionally, questions to vital signs and the fate of the foetuses were asked .
answers could be given on a nominally dichotomised or ordinal scale and for some questions free-text responses were required.
the ordinal scales were based on data of previous oral reports.fig.
<dig> part of the questionnaire given to the veterinary students.
this translated extract of the survey shows the relevant questions for this study.
it consists of  <dig> questions with one follow-up question
ethical approval
research activities involving human participants will require approval prior to their commencement.
therefore the opinion of the data protection officer of the university of leipzig has been obtained.
he confirmed an exemption from these formal requirements with regard to the following criteria:  the current study involves no foreseeable risk of harm or discomfort to participants and any further foreseeable risk would involve no more than inconvenience to participants, and  the study involves the use of existing collections of data or records that contain only non-identifiable data about persons, entities and bodies.
no names will be published.
data analyses
analyses were carried out using microsoft® excel®  <dig>  <dig> and ibm® spss® statistics  <dig> .
<dig> the specific data of each abattoir were encrypted and abattoirs were grouped by region in order to ensure their anonymity.
only completed questionnaires were included in the initial analysis.
due to the step-by-step design of the questionnaire, the number  of answers for each question differs as non-responders matched the exclusion criteria and hence were dropped out from further analyses.
the somers-d-test was used to determine the association between ordinal variables.
a p-value of <  <dig>  was considered significant for all comparisons.
RESULTS
participants and submission
the survey generated  <dig> responses in the period from january  <dig> to september  <dig>  all participants were students at the faculty of veterinary medicine, university of leipzig, germany.
students were interviewed after finishing their final examination in the subject “meat hygiene”.
participation was voluntary and anonymous.
of  <dig> cattle-questionnaires,  <dig>  described the situation at one abattoir.
<dig>  of those  <dig> confirmed the slaughter of female cattle and thus fulfilled the inclusion criteria to be examined further as shown in fig.
<dig>  the related internships took place between  <dig> and  <dig>  the majority however, in  <dig> ,  <dig>  and  <dig> , as depicted in fig.
<dig>  the students did their internships in  <dig> different slaughterhouses in germany  and abroad .
the  <dig> german abattoirs were located in  <dig> of the  <dig> federal states.
the majority of the abattoirs  was located in  <dig> federal states; bavaria , north rhine-westphalia  and baden-wuerttemberg .fig.
<dig> scheme of  evaluable and non-evaluable questionnaires and encoded abattoirs of the veterinary students´ survey.
only correctly completed questionnaires are included in the analysis.
due to the design of the questionnaire the number  of answers for each question can differ as non-responders were dropped from analyses
fig.
<dig> number of valid internship questionnaires  fielded in year of internship.
<dig> valid questionnaires have been examined.
most of the associated internships took place in  <dig> ,  <dig>  and  <dig> .
<dig> dates are not specified
numbers of slaughtered cattle and prevalence of gravid cows and heifers
the reported numbers of slaughtered female cattle are described by using a breakdown of ordinal categories.
the numbers differ between the  <dig> abattoirs.
of the  <dig> eligible questionnaires,  <dig>  cases slaughtered between 1– <dig>   <dig>  between 11– <dig>   <dig>  between 51– <dig>   <dig>  between 101– <dig>   <dig>  between 201– <dig> and  <dig>  more than  <dig> female cattle per day.
the majority of abattoirs are therefore small and medium-sized enterprises with a slaughter capacity of ≤ <dig> cows/day.
in  <dig>  of the  <dig> questionnaires that refer to the slaughter of female cattle, the participants answered the question about the occurrence and frequency of slaughtered gravid cattle.
in  <dig> cases , the slaughter of pregnant cattle was reported, although in  <dig> cases , this was never actually seen by the trainees themselves.
an analysis of the data from the related  <dig> slaughterhouses shows, that there are  <dig> abattoirs  that are always reported to slaughter pregnant cattle,  <dig>  where reports vary and  <dig>  that are never reported to slaughter gravid cattle.
in summary,  <dig> out of  <dig> abattoirs  that slaughter females also slaughter pregnant ones .
however  <dig> of the  <dig> positive cases  reported, that the slaughter of pregnant cattle occurs rarely ,  <dig> cases  described it as frequently , and only in  <dig> cases  pregnant cows were slaughtered often .
the proportion of pregnant cattle slaughtered rises with the total number of slaughtered females .
the correlation is significant .fig.
<dig> percentage of abattoirs  that are associated with slaughtering pregnant cattle.
as described in the student survey, these abattoirs  are never, sometimes or always associated with slaughtering pregnant cattle
the reported proportion  of pregnant cattle slaughtered in relation to the total number of slaughtered females per day is shown in this table
fig.
<dig> frequency of slaughtering gravid cattle in relation to total number of female cattle slaughtered daily.
this chart shows a positive tendency to slaughter gravid cows by rising number of daily slaughtered cows
enquiry was also made about the prevalence of slaughter cows in advanced gestational stages .
of  <dig> eligible questionnaires,  <dig>  reported advanced gravidities amongst the slaughter cows.
in fig.
<dig>  the correlation between the total number of gravid slaughter cows and the number of animals in higher gestational stages is depicted.
the rarer the slaughter of pregnant cattle was, the less often advanced gravidities were reported.
the correlation between those two aspects is significant .fig.
<dig> appearance of advanced gestational stages  in relation to frequency of slaughter of gravid cattle .
of the  <dig> respondents  <dig>  % reported advanced gestational stage of the slaughtered gravid cattle.
this case rises significantly with the frequency of culling pregnant cattle
foetuses – vital signs and fate
another aspect of the survey focused on the fate of the foetuses.
<dig>  of  <dig> respondents reported vital signs of the foetuses, such as independent movement and pulsation of the umbilical vessels.
irrespective of vital signs, one  of  <dig> respondents – as shown in fig.
<dig> – reported about special measures that were taken to kill the foetus .
the methods of euthanasia were not questioned, indeed.
one student indicated that upon request, the official veterinarian stated that the foetus would die due to the cessation of uterine blood supply and that no special measures are needed.
moreover, the slaughter of pregnant farm animals also occurs to other species, as described for sheep by another student.
discussion
limitations
this survey is an observational, cross-sectional study based on students’ reports on their compulsory slaughterhouse internship, which took place  <dig> to 18 month before their final exam in “meat hygiene”.
these time delays as well as the post exam situation are possible confounding factors that may affect the results of the study.
however, all students attended a special briefing that focused on both general and specific aspects of their slaughterhouse internship.
in addition, they were asked to write a voluntary, anonymous report.
therefore students were well prepared for the internship and their report served them as a helpful reminder for both, the exam preparation and the survey.
in their lectures of embryology and dairy reproduction as well as in their clinical internships, the students learned to classify the stage of gravidity on the basis of the crown-rump length, eruptions of teeth, development of fur and teeth and position and size of the foetus.
thus, knowledge of these fundamentals was assumed to be compulsory.
although the survey was conducted without knowledge of the abattoirs and the local competent authorities, this approach is acceptable.
student internship reports are common practice in many professions and the survey of students and official veterinarians on their experiences during the slaughterhouse internship is carried out since  <dig>  special announcement of certain key issues would lead to bias and distortion of the data.
privacy is respected by investigation of a large number of different and anonymously evaluated abattoirs.
additionally, one should note that due to the structure of the internship  the reports represent only a snapshot rather than a complete overview of the actual situation in cattle slaughtering.
key results and interpretation
based on these “snapshots”, however, results show that in nearly every abattoir for cattle, females are slaughtered.
only in  <dig> of the  <dig> questionnaires , none of the given ordinal options have been selected, which could either mean that no female cattle were slaughtered or that the student did not recall or refused to answer the question.
the total ratio of females amongst all cattle slaughtered is unknown and irrelevant for this survey.
with  <dig> of  <dig> eligible cases , the share of pregnant cattle in this study is far higher than those reported by riehn et al., di nicolo, lücker et al., singleton and dobson, herenda and others .
due to study design though, the data should be interpreted with care because students during their internship have limited experience regarding the assessment and interpretation of findings in comparison to an official veterinarian.
in addition, these  <dig> questionnaires were related to only  <dig> abattoirs.
besides,  <dig> of this  <dig> slaughterhouses were also reported in other questionnaires, where the participant never actually saw it directly.
so the information can be repeated in the same and also in other abattoirs.
moreover, a high level of attentiveness and empathy might have influenced their perception particularly with regard to health or welfare problems.
on the other hand, the aforementioned points of criticism may also be interpreted as an advantage for the present study: it offers the rare opportunity to collect information from external but yet competent observers.
even though the semi-quantitative approach of the study does not permit an exact conclusion on the actual prevalence of the slaughter of pregnant cattle, the high number of positive reports  shows unequivocally that the slaughter of pregnant cattle is not an exceptional event but occurs regularly even though at a different frequency of occurrence.
this might also be due to the fact that large shares of the abattoirs  are small and medium-sized holdings with slaughter volumes of less than  <dig> female cattle per day.
these small holdings may operate on a more local level are therefore not affected in the same way by fluctuations of suppliers on farm and transportation level as bigger, supra-regionally operating enterprises.
this may result in above- or beyond-average shares of pregnant cattle in smaller plants depending of the practises in the supplying farms and the subsequent stages of the food chain.
however, the present study includes many more abattoirs of different sizes and locations than former investigations on this issue.
the high proportion of questionnaires  reporting the slaughter of cattle during advanced gestational stages supports the findings of previous studies reporting the same phenomenon  <cit> .
however the data should be interpreted with care because differences in methodology may influence the results.
an important point in this context is without doubt, that during the ante- and post-mortem inspection of slaughter cattle, later stages of gestation  are easier to diagnose then earlier stages.
furthermore, the study provides only qualitative data and is therefore not directly comparable to other studies.
a completely new aspect of this study is the focus on foetal life signs.
respondents report only in  <dig> of  <dig> cases  that foetal vital signs were recognizable.
in only one of these cases the foetus was euthanized.
this is not compatible with the animal welfare guidelines regarding the culling of pregnant animals in case of epizooty  <cit> .
these guidelines recommend a separate euthanasia of foetuses by injection of pentobarbital after electrical stunning of the cow.
the drug diffuses through the placenta and causes a loss of consciousness and - in a high dose – paralyses the respiratory and circulatory centre leading to a rapid death  <cit> .
without such measures foetuses die by hypoxia.
although a number of studies  assume that due to low levels in foetal circulation, and the actions of other suppressors, it is unlikely that awareness occurs in the foetus during the death caused by hypoxia, a suffering of foetuses can not be completely ruled out  <cit> .
it is for example questionable in this context whether only the cortex is actually involved in conscious perception or also other structures like the brainstem.
in addition, is still controversial whether the prenatal measurements of eeg, which form the basis for the studies of mellor et al.
<cit> , are comparable with the eeg reactions of an adult animal  <cit> .
because of these reasonable doubts the german government has tried to initiate a change of the existing european law to prevent a possible suffering of foetuses in later gestational stages  <cit> .
CONCLUSIONS
the results of the present study show that the slaughter of pregnant cattle is a common and widespread practice in german abattoirs.
of  <dig> evaluable questionnaires,  <dig>  mention the slaughter of pregnant cattle, corresponding to  <dig>  % of all visited abattoirs.
slaughter of pregnant cattle is reported often  in  <dig> , frequently  in  <dig> , and rarely  in  <dig>  of all cases  respectively.
hence, the scvph’s assumption that pregnant cattle are only slaughtered in rare exceptional cases  <cit>  can no longer be maintained.
about 50 % of these animals were reported to be in the second or third stage of gestation.
the high proportion of foetuses in the second and third gestational stage emphasises the relevance for animal welfare.
in addition,  <dig>  of  <dig> questionnaires, providing information about the foetus, state that the foetus shows visible vital signs after the death of the mother.
where at present pain, suffering, and injury of the foetus during the slaughter of the mother cannot be excluded with absolute certainly, slaughter of pregnant farm animals must be considered as a pressing issue related to animal welfare.
in this context suitable studies regarding  the prevalence of the slaughter of pregnant cattle in german and european abattoirs,  the state of gestation of these animals, and  the condition of the mother and the foetus with regard to welfare related parameters have to be initiated promptly.
in addition, studies, regarding the sensitiveness and perceptiveness of foetuses during late pregnancy and at the time of birth have to be performed in order to elucidate the lack of scientific data in this context.
abbreviations
scvph, scientific committee on veterinary measures relating to public health
<dig> microsoft corporation, one microsoft way, redmond, wa 98052– <dig>  usa <https://products.office.com/de-de/home>
<dig> ibm deutschland gmbh, ibm-allee  <dig>   <dig> ehningen, germany <http://www.ibm.com/de/de/>

 current developments in public opinion and politics germany has one of the strictest animal welfare laws worldwide. there is no other country in the european union, which integrated animal welfare into its constitution – in germany animal welfare was made a national objective already in. in recent years the slaughter of pregnant cattle has gained importance in the public debate on animal welfare. due to scientific work by, amongst others, peisker et al., riehn et al., di nicolo, lücker et al., a political and scientific debate has emerged about whether the slaughter of pregnant animals can be reconciled with the requirements for a humane killing of animals. one of the major ethical concerns in this context is the perceptual awareness and viability of foetuses during the slaughter of the mother. marahrens and schwarzlose of germany’s federal research institute for animal health promote the opinion that foetuses in the 3rd trimester will have a relevant reduced welfare during the slaughter of their mother. the authors state, that more research is needed to assess the observed changes in physiological, electrophysiological, and endocrinological parameters of the foetuses that are exposed to such a treatment. in march public interest was attracted by a television report that addressed the suffering of foetuses during slaughter. the increased media interest on animal welfare issues related to slaughter in germany and abroad has caused german politicians to focus on these topics. the on-going dialogue led to a request in the course of the standing committee on the food chain and animal health meeting in brussels, april 8th. in response to this, a mandate was given to the european food safety administration by the european commission in order to investigate the scope of this problem and develop possible solutions. additionally, if needed, the council regulation no 1099/ on the protection of animals at the time of slaughter should be reviewed with respect to protection of the unborn life. appearance of the problem the slaughter of pregnant cattle was considered negligible by the scientific committee on veterinary measures relating to public health in. according to the scvph “meat consumption from pregnant heifers is exceptional as usually these animals are not slaughtered”. some studies, however, have since contradicted these assumptions and demonstrated that the actual numbers are much higher. table  gives an overview of study results for the prevalence of slaughter of gravid cattle in germany and some other countries. prevalence in german abattoirs ranges from  % up to 15 %. in luxembourg, belgium and italy the proportion of pregnant animals is  %,  %, and  % respectively. in two british abattoirs, singleton and dobson observed that  % of the cows were pregnant. as depicted in table  most of the cows were in the 2nd and 3rd trimester at the time of slaughter. the fact, that hardly cows in the 1st trimester were observed may be attributed to the circumstance that early pregnancies may be overlooked on both farm and abattoir level. generally, the data from the different studies should be interpreted with care, as different study designs may impede their comparability.table prevalence of slaughtering gravid cows in germany and other countries – results of different authors different authors described the prevalence of slaughtering gravid cows and their stage of gravidity in germany and some other countries. however, the problem cannot be underestimated in its significance, since not only cattle but also other species are effected as demonstrated by fayemi and muchenje. legal and ethical aspects there are no regulations, neither in national nor in community law, prohibiting the slaughter of pregnant animals and governing the fate of the foetuses. due to a supposed underestimation of the total prevalence by the scvph and the lack of reliable data legislators at european level have not issued any mandatory regulations on how to handle the problem. in addition, no options are granted to the member states to adopt any regulations with regard to this issue at national level. currently the only statute protecting females around the time of calving is the eu transport regulation – regulation 1/ annex i, chapter i nr. c. it prohibits the transport of “pregnant females for whom 90 % or more of the expected gestation period has already passed, or females who have given birth in the previous week”. riehn et al. indicate that determining the correct percentage of gestation is almost impossible on abattoir level, where only limited examination opportunities are available during pre-mortem inspection. the authors also state, that the regulation 854/ obliges the official veterinarian nevertheless to do a pre-mortem inspection “to verify compliance with relevant community and national rules on animal welfare, such as rules concerning the protection of animals at the time of slaughter and during transport”. the fate of foetuses is also not specifically mentioned in any regulation. however, chapter ii, article of the regulation 1099/ states that “animals shall be spared any avoidable pain, distress or suffering during their killing and related operations“ and that “business operators shall, in particular, take the necessary measures to ensure that animals are provided with physical comfort and protection” and “do not show signs of avoidable pain or fear or exhibit abnormal behaviour“. to date there is a dispute if and from which developmental stage on foetuses are conscious and sensitive to stress. former studies, especially by mellor et al. assume that foetuses lack such abilities. this opinion may be reviewed in the light of new scientific evidence. bellieni and buonocore report that foetuses are able to feel stress and pain from the second half of the gestation on. the experimental animals directive 2010/63/eu revising directive 86/609/eec on the protection of animals used for scientific purposes already considers these new research results and states in recital that “ there is scientific evidence showing that such in the last third of the period of their development are at an increased risk of experiencing pain, suffering and distress,.” altogether, it cannot be ruled out that foetuses feel pain, distress and other forms of suffering and therefore the slaughter of pregnant cattle in advanced gestational stages should be considered as an animal welfare problem. the reasons on farm level for slaughtering gravid cows can only be assumed in the absence of valid data. the federal association of veterinary officers germany presumes the following reasons: slaughter by mistake with unknown pregnancy; injured animals, which cannot be used any more; economic reasons. the relevance of economic aspects in this context is stressed by many authors e.g. riehn et al., cordes, münch and richter, tierärztliche vereinigung für tierschutz e.v.. objective considering the heterogeneous data and study designs of previous german studies while respecting their relevance for further political development, our objectives were to i) determine the prevalence of the slaughter of pregnant cattle in germany semi-quantitatively and ii) to investigate the occurring gestational stages and fate of the foetuses. methods survey design and questionnaire for this investigation, an observational, cross-sectional study design was used. a voluntary and anonymous survey with specific questions was conducted amongst all final-year-students of the faculty of veterinary medicine of the university of leipzig from january until september in germany the study of veterinary medicine is regulated by the “verordnung zur approbation von tierärztinnen und tierärzten”. the regulation stipulates that every student has to absolve a slaughterhouse-internship of at least 100 hours in three weeks under the supervision of the local competent authority. in the course of the internship, students are required to learn and practice the ante- and post-mortem inspection of cattle and pigs, taking particular care of animal welfare. our study is therefore aimed at the observations of the veterinary trainees during their meat hygiene internship. general information and preparation for the internship was conducted during a short obligatory briefing as part of the meat hygiene lecture. in addition to the general organizational information, students were asked to pay attention to specific aspects such as the slaughter of pregnant cattle and write a voluntary, anonymous internship report. from january until september following their final exam in meat hygiene, all students of the faculty of veterinary medicine of the university of leipzig were asked to participate in a survey. participation was voluntary, anonymous, and had no influence on exam results. the survey consisted of two questionnaires– one for cattle and one for pigs – each containing five groups of questions about ante- and post-mortem inspection and animal welfare. for each species and abattoir the students were asked to indicate the date and abattoir of their internships. one set of questions addressed the prevalence of the slaughter of female cattle and the frequency of pregnancy amongst the cows and heifers including their stage of gestation as recognized by the students. additionally, questions to vital signs and the fate of the foetuses were asked. answers could be given on a nominally dichotomised or ordinal scale and for some questions free-text responses were required. the ordinal scales were based on data of previous oral reports.fig. part of the questionnaire given to the veterinary students. this translated extract of the survey shows the relevant questions for this study. it consists of questions with one follow-up question ethical approval research activities involving human participants will require approval prior to their commencement. therefore the opinion of the data protection officer of the university of leipzig has been obtained. he confirmed an exemption from these formal requirements with regard to the following criteria: the current study involves no foreseeable risk of harm or discomfort to participants and any further foreseeable risk would involve no more than inconvenience to participants, and the study involves the use of existing collections of data or records that contain only non-identifiable data about persons, entities and bodies. no names will be published. data analyses analyses were carried out using microsoft® excel® and ibm® spss® statistics. the specific data of each abattoir were encrypted and abattoirs were grouped by region in order to ensure their anonymity. only completed questionnaires were included in the initial analysis. due to the step-by-step design of the questionnaire, the number of answers for each question differs as non-responders matched the exclusion criteria and hence were dropped out from further analyses. the somers-d-test was used to determine the association between ordinal variables. a p-value of <  was considered significant for all comparisons.  participants and submission the survey generated responses in the period from january to september all participants were students at the faculty of veterinary medicine, university of leipzig, germany. students were interviewed after finishing their final examination in the subject “meat hygiene”. participation was voluntary and anonymous. of cattle-questionnaires, described the situation at one abattoir. of those confirmed the slaughter of female cattle and thus fulfilled the inclusion criteria to be examined further as shown in fig.  the related internships took place between and the majority however, in, and, as depicted in fig.  the students did their internships in different slaughterhouses in germany and abroad. the german abattoirs were located in of the federal states. the majority of the abattoirs was located in federal states; bavaria, north rhine-westphalia and baden-wuerttemberg.fig. scheme of evaluable and non-evaluable questionnaires and encoded abattoirs of the veterinary students´ survey. only correctly completed questionnaires are included in the analysis. due to the design of the questionnaire the number of answers for each question can differ as non-responders were dropped from analyses fig. number of valid internship questionnaires fielded in year of internship. valid questionnaires have been examined. most of the associated internships took place in, and. dates are not specified numbers of slaughtered cattle and prevalence of gravid cows and heifers the reported numbers of slaughtered female cattle are described by using a breakdown of ordinal categories. the numbers differ between the abattoirs. of the eligible questionnaires, cases slaughtered between 1– between 11– between 51– between 101– between 201– and more than female cattle per day. the majority of abattoirs are therefore small and medium-sized enterprises with a slaughter capacity of ≤ cows/day. in of the questionnaires that refer to the slaughter of female cattle, the participants answered the question about the occurrence and frequency of slaughtered gravid cattle. in cases, the slaughter of pregnant cattle was reported, although in cases, this was never actually seen by the trainees themselves. an analysis of the data from the related slaughterhouses shows, that there are abattoirs that are always reported to slaughter pregnant cattle, where reports vary and that are never reported to slaughter gravid cattle. in summary, out of abattoirs that slaughter females also slaughter pregnant ones. however of the positive cases reported, that the slaughter of pregnant cattle occurs rarely, cases described it as frequently, and only in cases pregnant cows were slaughtered often. the proportion of pregnant cattle slaughtered rises with the total number of slaughtered females. the correlation is significant.fig. percentage of abattoirs that are associated with slaughtering pregnant cattle. as described in the student survey, these abattoirs are never, sometimes or always associated with slaughtering pregnant cattle the reported proportion of pregnant cattle slaughtered in relation to the total number of slaughtered females per day is shown in this table fig. frequency of slaughtering gravid cattle in relation to total number of female cattle slaughtered daily. this chart shows a positive tendency to slaughter gravid cows by rising number of daily slaughtered cows enquiry was also made about the prevalence of slaughter cows in advanced gestational stages. of eligible questionnaires, reported advanced gravidities amongst the slaughter cows. in fig.  the correlation between the total number of gravid slaughter cows and the number of animals in higher gestational stages is depicted. the rarer the slaughter of pregnant cattle was, the less often advanced gravidities were reported. the correlation between those two aspects is significant.fig. appearance of advanced gestational stages in relation to frequency of slaughter of gravid cattle. of the respondents  % reported advanced gestational stage of the slaughtered gravid cattle. this case rises significantly with the frequency of culling pregnant cattle foetuses – vital signs and fate another aspect of the survey focused on the fate of the foetuses. of respondents reported vital signs of the foetuses, such as independent movement and pulsation of the umbilical vessels. irrespective of vital signs, one of respondents – as shown in fig.  – reported about special measures that were taken to kill the foetus. the methods of euthanasia were not questioned, indeed. one student indicated that upon request, the official veterinarian stated that the foetus would die due to the cessation of uterine blood supply and that no special measures are needed. moreover, the slaughter of pregnant farm animals also occurs to other species, as described for sheep by another student. discussion limitations this survey is an observational, cross-sectional study based on students’ reports on their compulsory slaughterhouse internship, which took place to 18 month before their final exam in “meat hygiene”. these time delays as well as the post exam situation are possible confounding factors that may affect the results of the study. however, all students attended a special briefing that focused on both general and specific aspects of their slaughterhouse internship. in addition, they were asked to write a voluntary, anonymous report. therefore students were well prepared for the internship and their report served them as a helpful reminder for both, the exam preparation and the survey. in their lectures of embryology and dairy reproduction as well as in their clinical internships, the students learned to classify the stage of gravidity on the basis of the crown-rump length, eruptions of teeth, development of fur and teeth and position and size of the foetus. thus, knowledge of these fundamentals was assumed to be compulsory. although the survey was conducted without knowledge of the abattoirs and the local competent authorities, this approach is acceptable. student internship reports are common practice in many professions and the survey of students and official veterinarians on their experiences during the slaughterhouse internship is carried out since special announcement of certain key issues would lead to bias and distortion of the data. privacy is respected by investigation of a large number of different and anonymously evaluated abattoirs. additionally, one should note that due to the structure of the internship the reports represent only a snapshot rather than a complete overview of the actual situation in cattle slaughtering. key results and interpretation based on these “snapshots”, however, results show that in nearly every abattoir for cattle, females are slaughtered. only in of the questionnaires, none of the given ordinal options have been selected, which could either mean that no female cattle were slaughtered or that the student did not recall or refused to answer the question. the total ratio of females amongst all cattle slaughtered is unknown and irrelevant for this survey. with of eligible cases, the share of pregnant cattle in this study is far higher than those reported by riehn et al., di nicolo, lücker et al., singleton and dobson, herenda and others. due to study design though, the data should be interpreted with care because students during their internship have limited experience regarding the assessment and interpretation of findings in comparison to an official veterinarian. in addition, these questionnaires were related to only abattoirs. besides, of this slaughterhouses were also reported in other questionnaires, where the participant never actually saw it directly. so the information can be repeated in the same and also in other abattoirs. moreover, a high level of attentiveness and empathy might have influenced their perception particularly with regard to health or welfare problems. on the other hand, the aforementioned points of criticism may also be interpreted as an advantage for the present study: it offers the rare opportunity to collect information from external but yet competent observers. even though the semi-quantitative approach of the study does not permit an exact conclusion on the actual prevalence of the slaughter of pregnant cattle, the high number of positive reports shows unequivocally that the slaughter of pregnant cattle is not an exceptional event but occurs regularly even though at a different frequency of occurrence. this might also be due to the fact that large shares of the abattoirs are small and medium-sized holdings with slaughter volumes of less than female cattle per day. these small holdings may operate on a more local level are therefore not affected in the same way by fluctuations of suppliers on farm and transportation level as bigger, supra-regionally operating enterprises. this may result in above- or beyond-average shares of pregnant cattle in smaller plants depending of the practises in the supplying farms and the subsequent stages of the food chain. however, the present study includes many more abattoirs of different sizes and locations than former investigations on this issue. the high proportion of questionnaires reporting the slaughter of cattle during advanced gestational stages supports the findings of previous studies reporting the same phenomenon. however the data should be interpreted with care because differences in methodology may influence the results. an important point in this context is without doubt, that during the ante- and post-mortem inspection of slaughter cattle, later stages of gestation are easier to diagnose then earlier stages. furthermore, the study provides only qualitative data and is therefore not directly comparable to other studies. a completely new aspect of this study is the focus on foetal life signs. respondents report only in of cases that foetal vital signs were recognizable. in only one of these cases the foetus was euthanized. this is not compatible with the animal welfare guidelines regarding the culling of pregnant animals in case of epizooty. these guidelines recommend a separate euthanasia of foetuses by injection of pentobarbital after electrical stunning of the cow. the drug diffuses through the placenta and causes a loss of consciousness and - in a high dose – paralyses the respiratory and circulatory centre leading to a rapid death. without such measures foetuses die by hypoxia. although a number of studies assume that due to low levels in foetal circulation, and the actions of other suppressors, it is unlikely that awareness occurs in the foetus during the death caused by hypoxia, a suffering of foetuses can not be completely ruled out. it is for example questionable in this context whether only the cortex is actually involved in conscious perception or also other structures like the brainstem. in addition, is still controversial whether the prenatal measurements of eeg, which form the basis for the studies of mellor et al., are comparable with the eeg reactions of an adult animal. because of these reasonable doubts the german government has tried to initiate a change of the existing european law to prevent a possible suffering of foetuses in later gestational stages.  the results of the present study show that the slaughter of pregnant cattle is a common and widespread practice in german abattoirs. of evaluable questionnaires, mention the slaughter of pregnant cattle, corresponding to  % of all visited abattoirs. slaughter of pregnant cattle is reported often in, frequently in, and rarely in of all cases respectively. hence, the scvph’s assumption that pregnant cattle are only slaughtered in rare exceptional cases can no longer be maintained. about 50 % of these animals were reported to be in the second or third stage of gestation. the high proportion of foetuses in the second and third gestational stage emphasises the relevance for animal welfare. in addition, of questionnaires, providing information about the foetus, state that the foetus shows visible vital signs after the death of the mother. where at present pain, suffering, and injury of the foetus during the slaughter of the mother cannot be excluded with absolute certainly, slaughter of pregnant farm animals must be considered as a pressing issue related to animal welfare. in this context suitable studies regarding the prevalence of the slaughter of pregnant cattle in german and european abattoirs, the state of gestation of these animals, and the condition of the mother and the foetus with regard to welfare related parameters have to be initiated promptly. in addition, studies, regarding the sensitiveness and perceptiveness of foetuses during late pregnancy and at the time of birth have to be performed in order to elucidate the lack of scientific data in this context. abbreviations scvph, scientific committee on veterinary measures relating to public health microsoft corporation, one microsoft way, redmond, wa 98052– usa <https://products.office.com/de-de/home> ibm deutschland gmbh, ibm-allee ehningen, germany <http://www.ibm.com/de/de/> 
the scientific committee on veterinary measures relating to public health, however, does not believe this topic to be a critical issue because of the hitherto supposed rare occurrence of this practice. the results show that the slaughter of pregnant cattle is a common and widespread practice in german abattoirs. of evaluable questionnaires, mention the slaughter of pregnant cattle, corresponding to  % of all visited abattoirs. some previous studies though, contradict this assessment, emphasising its relevance to animal welfare. with regard to the heterogeneous study design of previous investigations, the objective of this study is to evaluate the current situation concerning the slaughter of pregnant cattle in different german abattoirs. the slaughter of pregnant cattle and the fate of the foetuses are relatively new subjects in the field of animal welfare. slaughter of pregnant cattle is reported often in, frequently in, and rarely in of all cases respectively. the scvph’s assumption that pregnant cattle are only slaughtered in rare exceptional cases can no longer be maintained. in this context the implementation of suitable studies and detailed analysis of the current situation is indispensable to ensure the high standards in animal welfare in germany and europe. veterinary public healthanimal welfarepregnancygravid cattlefoetusabattoirslaughterhouseconsumer protectionissue-copyright-statement© the author 2016 the high proportion of foetuses in the second and third gestational stage must also be considered. of questionnaires providing information about the foetus, state that the foetus showed visible vital signs after the death of the mother, but in one case the foetus was euthanized subsequently. additionally, the prevalence was assessed semi-quantitatively on the basis of a cross-sectional, voluntary and anonymous survey that was conducted amongst senior veterinary students of the university of leipzig from until 
 the slaughter of pregnant cattle and the fate of the foetuses are relatively new subjects in the field of animal welfare. the scientific committee on veterinary measures relating to public health, however, does not believe this topic to be a critical issue because of the hitherto supposed rare occurrence of this practice. some previous studies though, contradict this assessment, emphasising its relevance to animal welfare. with regard to the heterogeneous study design of previous investigations, the objective of this study is to evaluate the current situation concerning the slaughter of pregnant cattle in different german abattoirs. additionally, the prevalence was assessed semi-quantitatively on the basis of a cross-sectional, voluntary and anonymous survey that was conducted amongst senior veterinary students of the university of leipzig from until  of evaluable questionnaires, mention the slaughter of pregnant cattle, corresponding to  % of all visited abattoirs. slaughter of pregnant cattle is reported often in, frequently in, and rarely in of all cases respectively. about 50 % of these animals were reported to be in the second or third stage of gestation. of questionnaires providing information about the foetus, state that the foetus showed visible vital signs after the death of the mother, but in one case the foetus was euthanized subsequently.  the results show that the slaughter of pregnant cattle is a common and widespread practice in german abattoirs. the scvph’s assumption that pregnant cattle are only slaughtered in rare exceptional cases can no longer be maintained. the high proportion of foetuses in the second and third gestational stage must also be considered. in this context the implementation of suitable studies and detailed analysis of the current situation is indispensable to ensure the high standards in animal welfare in germany and europe. keywords veterinary public healthanimal welfarepregnancygravid cattlefoetusabattoirslaughterhouseconsumer protectionissue-copyright-statement© the author 2016 