Mark J. Farnworth

Heritability of post-mixing aggressiveness in grower-stage pigs and its relationship with production traits

Mixing of commercial pigs frequently leads to intense aggression. Considerable phenotypic variation exists between individuals and selection against aggressiveness may offer a long-term reduction in aggression without incurring additional costs to the primary producer. The genetic contribution to aggressiveness was quantified in this study using the number of skin lesions as an indicator of involvement in aggression. A sample of 1132 pigs were mixed at an average weight of 27·9 (s.d. 4·6) kg into 96 pens on a commercial sire line nucleus unit. Post-mixing aggressiveness of pigs was assessed using the lesion score (LS) approach. Growth rate, between 27·9 and 91·9kg, and backfat depth at 91·9kg were recorded for a subsample of 658 pigs. With a pedigree file of 1947 animals, a heritability of 0·22 was estimated for the LS trait. No significant genetic or phenotypic correlations were found between LS and growth rate or backfat depth, but standard errors of estimates were large. The response to selection, when all selection pressure was placed on the LS trait, was a 25% reduction in LS per generation. It is therefore technically possible to select for a reduced LS without substantially inhibiting genetic progress in growth rate or backfat depth through antagonistic genetic relationships.

What's in a Name? Perceptions of Stray and Feral Cat Welfare and Control in Aotearoa, New Zealand

New Zealanders (n = 354) rated the acceptability of lethal and nonlethal cat control methods and the importance of conservation and welfare. Lethal control was more acceptable for feral cats than strays; for nonlethal control, the inverse was true. More than concern for the welfare of cats subjected to control, perceived conservation benefits, risk of disease transfer, and companion cat welfare dictated the acceptability of control measures. Similarly, the welfare consideration for groups of cats differed, transitioning from companion (highest) to feral (lowest). Differences in attitudes toward acceptability of control methods were evident. In particular, nonhuman animal professionals ranked lethal control as more acceptable than did nonanimal professionals. Cat caregivers (owners) considered both conservation and welfare issues of greater importance than did nonowners. Owners ranked the acceptability of nonlethal control methods higher for stray cats, but not feral, than did nonowners. This research indicates that the use of the terms stray and feral may have significant impact on cats in New Zealand. There is also a greater consideration of conservation values than of welfare in stray and feral cat control.

Current Attitudes Toward, and Incidence of, Sterilization of Cats and Dogs by Caregivers (Owners) in Auckland, New Zealand

This study distributed a questionnaire to cat or dog caregivers (owners) throughout Auckland, New Zealand, to investigate the attitudes of human companions toward the sterilization of their cats and dogs and the degree to which this occurs relative to demographic information gathered. A total of 276 recipients returned questionnaires with data pertinent to 477 cats and dogs. Female owners were more likely than were males to sterilize cats or dogs: 90.2% sterilization rate compared with 80%. Statistical trends also suggested that owners with a postschool education had a higher percentage of sterilized nonhuman animals than owners with no postschool or only school-age education. Cats were more likely than dogs to be neutered: 91.7% versus 78.5%. Companion animals not annually vaccinated were more likely to be sterilized than animals who were vaccinated annually: 93.6% and 85.4%. The study also showed gender bias and age differences in owner attitudes toward a number of the statements regarding sterilization, with male owners more likely to be concerned about the effect of neutering or spaying on the sexuality or masculinity of the animal.

The legal status of cats in New Zealand: a perspective on the welfare of companion, stray, and feral domestic cats (Felis catus).

Pinpointing and safeguarding the welfare status of domestic cats is problematic, especially in New Zealand where cats are introduced predators with significant impact on indigenous fauna. Usually the identification of welfare status depends on conservational, legal, and public attitudes that are often contrasting. Cats may rapidly transgress definitions placed on them, confounding attempts to categorize them. In 1 generation, cats can move from a human-dependent state (“stray” or “companion”) to wild (“feral”). Often this categorization uses arbitrary behavioral and or situational parameters; consequent treatment and welfare protection for these cats are similarly affected. Terminology used to describe cats is not equitable across research. However, the New Zealand Animal Welfare (Companion Cats) Code of Welfare 2007 seeks to create a new definition of the terms companion, stray, and feral. It distinguishes between cats who live within and without human social constructs. This legislation mandates that cats in human environments or indirectly dependent on humans cannot be classified as feral. Such definitions may prove vital when safeguarding the welfare of free-living domestic cats and cat colonies.

Understanding Attitudes Toward the Control of Nonnative Wild and Feral Mammals: Similarities and Differences in the Opinions of the General Public, Animal Protectionists, and Conservationists in New Zealand (Aotearoa)

Lethal control is used extensively in New Zealand to control nonnative nonhuman mammals. Respondents were surveyed about 8 mammal groups considered pests and their attitudes toward their control and pest status. They also identified the most appropriate method of control for the 8 different mammals. Information was gathered from 3 groups of respondents: nonhuman animal protectionists, conservationists, and the general public. Conservationists routinely rated all animal groups as more severe pests than the general public or animal protectionists, who provided the lowest scores. Rats, stoats, brushtail possums, and rabbits were identified as the 4 most serious pests by all 3 groups. Conservationists were 5.7 and 2.6 times more likely to prefer a lethal method of control than protectionists and the general public, respectively. For all 3 groups an increase in pest score for a given animal saw a decline in importance placed upon the animals welfare. This relationship was strong for the general public but weak for conservationists and animal protectionists. Understanding aspects of potentially opposing viewpoints may be invaluable in supporting the development of new welfare-focused control methods.

Early weaning results in less active behaviour, accompanied by lower 5-HT1A and higher 5-HT2A receptor mRNA expression in specific brain regions of female pigs

In rodents and humans stressful events in early life e.g. maternal deprivation, can increase sensitivity to stress in later life. Humans may become more susceptible to mood disorders, e.g. depression. In livestock species, such as pigs, early weaning is a form of maternal deprivation. We investigated behavioural consequences in 99 female pigs weaned at three different ages (12, 21 and 42 days; d12, d21, d42). Pigs were habituated to an open field arena over 6 days before being given 5-min open-field tests over three subsequent days (days 77-79). Early-weaned pigs (d12) showed behavioural inhibition (reduced vocalisations and lower activity) compared with later-weaned pigs, although in all groups these measures declined over the three tests, so this treatment difference might reflect more rapid habituation to the test in d12 pigs. Long-term effects on mood-related 5-HT receptor subtypes were measured in the brain at 90 days in a random sample of the d12 (n=8) and d42 pigs (n=8), using (3)H-ligand-binding and autoradiography and in situ hybridisation histochemistry. There were no differences between weaning ages in binding of (3)H-8-OH-DPAT (5-HT(1A) receptor agonist) or of (3)H-ketanserin (5-HT(2A) receptor antagonist) to any brain region studied. In d12 pigs, 5-HT(1A) receptor mRNA expression per unit area was 29%, 63%, 52% and 64% lower than in d42 pigs in the parvocellular PVN, amygdala and hippocampal dentate gyrus and pyramidal cell layer, respectively. The ratio of expression per cell to expressing cells per unit area was also lower, by 31%, in the pars horizontalis of the PVN in d12 pigs. Conversely, 5-HT(2A) receptor mRNA was expressed at a 25% and 28% higher density per unit area in the amygdala and pyramidal cell layer of the hippocampus, respectively, in these d12 pigs. In individual pigs, across brain regions, 5-HT(1A) receptor mRNA data were 70-79% correlated with binding data but no correlation was found for 5-HT(2A) data, suggesting different regulatory mechanisms. The behavioural and neurobiological responses to early weaning might represent either dysfunction or adaptation. Further investigation is required.

An exploration of attitudes towards pedigree dogs and their disorders as expressed by a sample of companion animal veterinarians in New Zealand

Abstract AIMS: To explore veterinary perceptions of inherited disorders in pedigree dogs within New Zealand and how these affect animal health and welfare. METHODS: An online questionnaire was distributed to the 647 members of the Companion Animal Society of the New Zealand Veterinary Association using an online survey system. The questionnaire collected details of practitioners, pedigree dog breeds and disorders most often encountered in practice, and responses to questions and statements regarding inherited disorders and pedigree dogs. RESULTS: Of the 216 respondents, 194 (89.8%) believed inherited disorders in dogs were a significant issue. The most commonly identified breeds presenting with inherited disorders were Boxer, Bulldog and German Shepherd dog. The most commonly reported inherited disorders were hip dysplasia, brachycephalic syndromes and elbow dysplasia. Of 207 respondents, 100 (48.3%) had advised clients against purchasing a pedigree dog due to common inherited disorders and 183 (85.6%) considered the health and welfare of some breeds to be too compromised to continue breeding. Of 199 respondents, 132 (66.3%) reported seeing no change in prevalence of inherited conditions, 103/204 (50.5%) reported seeing a positive change in attitudes towards inherited disorders among dog owners, and 81/207 (39.1%) thought legislative support would help decrease inherited disorders in pedigree dogs. Attitudes were not associated with time since graduation or ownership of a New Zealand Kennel Club registered breed of dog. The most common suggestions to decrease prevalence of inherited disorders were to alter breed standards, educate public or buyers and compulsory genetic testing. CONCLUSIONS: Among respondents, veterinarians considered inherited disorders as significant issues in a number of pedigree breeds. Veterinarians were concerned about inherited disorders in pedigree dogs, felt they had an obligation to treat such animals and were supportive of measures to make genetic testing for inheritable disorders a requirement for registration of pedigree breeds. CLINICAL RELEVANCE: Prevalence and perceived importance of inherited disorders influences how clinicians advise their clients. Respondents to this survey provided a number of mechanisms by which inherited disorders may be managed and these could form the basis of future discussions within the profession.

Public awareness in New Zealand of animal welfare legislation relating to cats

Abstract AIMS: To ascertain the levels of awareness of legislation governing the welfare of cats, and provision of basic care, including vaccination, by cat-owners within two locations in New Zealand. To assess the ability of respondents to differentiate between the terms ‘stray’ and ‘feral’. METHODS: A face-to-face questionnaire, consisting of 12 questions in three sections, was distributed by volunteers within Auckland (n=255) and Kaitaia (n=99) to gather information pertinent to the studys aims. Section 1 covered respondents’ personal details; Section 2, ownership and care of cats, including whether or not the cats were vaccinated against feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV); and Section 3, awareness of legislation and differences between the terms ‘stray’ and ‘feral’. RESULTS: Overall, fewer than half of respondents were aware of the animal welfare legislation within New Zealand or the semantic differences between the terms ‘stray’ and ‘feral’ as they appear in the dictionary. Respondents ≥41 years old, and individuals employed in the animal-related sector, were significantly more likely to be aware of the legislation and make the correct distinction between the terms compared with those aged ≤40, and those working in a non-animal-related profession. A significantly greater percentage of cat-owners (42%) provided care for cats they did not own compared with non-owners (26%). Results also indicated a large majority of cat-owners may consider standard annual vaccinations to include vaccination against FIV and FeLV. CONCLUSION: Dissemination of information about animal welfare legislation is important for the care of cats within New Zealand, and the definitions of the terms ‘stray’ and ‘feral’ need to be more clearly stated in order to prevent confusion. This is especially important when cats may be controlled using lethal measures under different legislative precedents that are not necessarily consistent with one another. CLINICAL RELEVANCE: Veterinary clinics may act as a primary source for the dissemination of information about relevant welfare acts as well as preventative health care, thus improving the welfare of cats. Cat-owners need to be better educated about the diseases covered by annual vaccination.

Incidence of dog bites and public attitudes towards dog care and management in Samoa

In many developing nations, dogs (Canis familiaris) present a significant issue in terms of human health, safety and animal welfare. We assessed attitudes towards dogs and their management in Samoa, a developing South Pacific island nation, using a questionnaire. It demonstrated that Samoa has one of the world’s highest recorded levels of household dog ownership (88%) but a comparatively low rate of vaccination (12%) and sterilisation (19%). Those interviewed believe dogs were important and should be considered part of the family; however most households reported that their dogs were kept for protection (79%). There was a clear skew in the sex distribution. The dog population showed a strong male bias (71%) suggesting females are removed from the population. Of those surveyed only 16% had received any education about dogs and their management and overall the respondents showed a clear disparity between attitudes and behaviour (eg the majority believe dogs should be vaccinated [81%] yet most dogs in this sample [72%] had never been to a veterinarian). Overall, there was a willingness to manage the free-roaming dog population which was considered by many to be a nuisance, however there were few enforceable mechanisms by which this could occur and most dogs were not confined. Harm or killing of dogs was relatively commonplace with 30% of households reporting they knew someone who had harmed or killed a dog and 26% of respondents indicating they believed harming or killing dogs was good for Samoan society, presumably by reducing problems associated with the free-roaming population. Dog bites were relatively frequent in Samoa and reports from two hospitals indicated a frequency of 37 new bites per annum requiring hospitalisation per 10,000 head of population. Furthermore, this paper outlines strategies and further research that could be considered to improve dog welfare and reduce the need to harm or kill dogs, namely improvements in veterinary provision and dog-focused education. It also considers the need for legislative controls and more research and funding to be made available for small developing nations to explore their animal welfare obligations.

Attitudes towards perception and management of pain in rabbits and guinea pigs by a sample of veterinarians in New Zealand

Abstract AIMS: To determine the perceptions of a sample of veterinarians in New Zealand regarding pain and pain management in rabbits and guinea pigs. METHODS: Questionnaires were distributed to all members of the Companion Animal Society, part of the New Zealand Veterinary Association. The questionnaire gathered information on the demographics of respondents, obtained an assessment by veterinarians of the level of pain associated with clinical procedures for rabbits and guinea pigs, established the willingness of respondents to perform these, obtained information on the anaesthetics and analgesics used during these procedures, and the factors associated with selecting different types of drug. The level of knowledge of respondents and interest in continuing education regarding pain recognition and management in these species was also assessed. RESULTS: A total of 155/610 (25.4%) responses were obtained. Rodents and lagomorphs accounted for 0–5% of the total caseload in the practices of most (133/155; 86%) respondents. Anticipated pain scores differed for different procedures (p<0.001) but did not differ between male and female respondents or between species of animal. There were also differences between procedures in the respondents willingness to perform them (p<0.001). Selection of anaesthetics and analgesics was mainly determined by the amount of information available for the species, and ketamine was the drug most commonly used. Many veterinarians felt their level of knowledge regarding the recognition and treatment of pain in rabbits and guinea pigs was inadequate. CONCLUSIONS: Rabbits and guinea pigs represented a small percentage of the caseload of veterinarians in this study. From an animal welfare perspective this may be of concern as, anecdotally, these species are common pets. However, further study regarding the actual number of these animals kept as pets in New Zealand is required for validation. Veterinary perception of anticipated pain, and willingness to perform procedures, varied between procedures, but was not influenced by gender of veterinarian. Many respondents felt their knowledge of issues relating to pain recognition, anaesthesia and analgesia in rabbits and guinea pigs was inadequate. CLINICAL RELEVANCE: Understanding how veterinarians choose to provide analgesia or when they decline to perform surgeries for rabbits and guinea pigs may provide significant information for targeting professional development, and improving animal welfare.