Flying foxes are keystone species on islands and are threatened worldwide, particularly by forest degradation, hunting and culling. They are often persecuted if they are perceived as agricultural pests, but the extent of crop damage from flying foxes and the factors triggering their visits to crops are not well established. This study aimed to investigate wildlife-caused damage to tankan oranges Citrus tankan on Okinawa Island, Japan, and interactions between the Ryukyu flying fox Pteropus dasymallus and farmers. We compiled data from three sources: official records of wildlife-caused crop damage, questionnaire surveys of 43 farmers and time-lapse camera surveys conducted at 14 locations during January–February 2018. Official records and the questionnaire survey indicated that the large-billed crow Corvus macrorhynchos caused most damage in a typical year (53–56% of the total damage), followed by P. dasymallus (18–28%). However, time-lapse camera surveys suggested negligible damage caused by P. dasymallus (2.1%) in 2018, a typhoon-free year. Farmers perceived a decline in local population size and stated that at least 2,000 P. dasymallus individuals had died in their orchards during 2008–2018. If this is extrapolated to the whole region, fatalities could have reached 6,500–8,500 individuals during that period. Binomial regression performed on official records demonstrated that damage by P. dasymallus was largely explained by interannual cyclonic activity. Prevalent netting practices could be a serious threat to P. dasymallus: 81% of interviewees reported that flying foxes die from entanglement in their nets. Nevertheless, half of these farmers were satisfied with current crop protection measures. These findings call for prompt remediation with particular focus on implementing more bat-friendly crop protection following strong typhoon seasons.

The most common method of culling impala (Aepyceros melampus) and many other antelope species in Africa was evaluated from a welfare point of view. The culling of 856 impala from 401 herds was observed and recorded in the Mkuzi Game Reserve, South Africa. Ninety-three per cent of animals were killed instantaneously by the first shot. Results indicated that herd size and composition, distance of herd from hunting vehicle and shot number all have a bearing on the number of animals wounded and missed. It is concluded that the culling of free-ranging impala by night-hunting in the manner described is a satisfactory method on welfare grounds, although a number of recommendations are made which might render the culling process more humane. It is argued that economic and welfare considerations are not necessarily in conflict, and long-term efficiency is likely to be enhanced by addressing both simultaneously.

In Australia, several macropod species are subjected to commercial harvesting, recreational hunting and population management, using both lethal and non-lethal measures. Some techniques for killing macropods can cause prolonged and/or severe suffering, and of particular concern is the welfare of remaining pouch young or young-at-foot, when females with dependent young are killed. Non-lethal methods are more widely supported by the general public and include reproductive control and relocation. These methods, however, also have significant associated welfare challenges. This review outlines the welfare concerns for each current method, and concludes that an accurate head-shot by an experienced shooter is least likely to inflict suffering. However, this assumes best practice shooting, which may not be representative of field conditions. Furthermore, many aspects of macropod control and killing still require significant research. These include, but are not limited to: accurate statistics for pouch young and young-at-foot mortality and morbidity in Australian states; data on field-based compliance with National Codes of Practice; safe and remote administration of reproductive control measures; and the impact of using dogs and trapping in wallaby destruction and hunting.

Methods for culling wild red deer (Cervus elaphus) were compared by observing behaviour and collecting post mortem samples from wild deer shot: (i) by a single stalker during daytime; (ii) by more than one stalker during daytime; (iii) by using a helicopter for the deployment of stalkers and carcase extraction; or (iv) by a single stalker at night, and compared with farmed red deer shot in a field or killed at a slaughterhouse. Culling by a single stalker during the day and shooting in a field were the most accurate in achieving placement of a shot in a target area, but when compared across all methods, there were no significant differences in the percentages of deer that were either wounded or appeared to have died immediately after the first shot. Plasma cortisol concentrations in deer shot using helicopter assistance were similar to those in deer at the slaughterhouse, but higher than deer shot at night or during the day by a single stalker, or in a field. Deer shot using helicopter assistance and also deer culled by a collaborative and single stalking during the day had lower muscle glycogen concentrations than those culled by a single stalker at night. There was no evidence that a particular culling method was associated with an increased risk of accidental or pre-culling injury. If a helicopter is used to assist culling, the deer are more likely to be disturbed before they are shot and therefore, measures should be taken to minimise the disturbance to the deer.

The objective of this study was to identify farm characteristics that were associated with cow (Bos taurus) welfare outcomes, including mortality rate, culling by 60 days of lactation, survival to ≥ 6 years of age and ≥ 5th parity (aged cows), somatic cell score, milk yield, and milk composition. Data were collected on housing systems, feeding systems, pasture strategies, bedding type, labour management practices and other farm characteristics in face-to-face interviews with 314 Pennsylvania dairy herd owners where performance records were available. Five herd management systems were identified in the sample: free-stalls with complete confinement (n = 37); free-stalls that allowed outdoor access (n = 76); tie-stalls with complete confinement (n = 52); tie-stalls with outdoor access and that fed a total mixed ration (n = 72); and tie-stalls with outdoor access and that did not feed a total mixed ration (n = 77). Welfare outcomes were evaluated with multivariable linear regression models and marginal means were estimated for herd management system. Tie-stalls that allowed outdoor access and that did not feed total mixed rations had the lowest mortality rate (2.0%), culling in the first 60 days of lactation (5.1%), and the highest proportion of aged cows (13.8%). Those herds also had high lifetime-to-date milk yield, a low proportion of fat-protein inversions, and low somatic cell scores. Free-stalls with complete confinement had significantly higher levels of mortality (8.3%), culling in the first 60 days of lactation (9.7%), and fewer aged cows (6.4%). It was concluded that shifts toward more efficient herd management systems have not benefited cow health and welfare. This suggests that cow welfare has been compromised to facilitate the economic survival of dairy farms.

At least one-third of the land on earth is used for agricultural production and conflicts with the interests of wildlife are inevitable. These conflicts are likely to escalate as the human population expands and as the scale and intensity of agricultural production increases. This paper argues that the same underlying causes frequently affect both wild animal welfare and conservation. Three key threats are discussed: disease transmission from domestic animals and the interventions used to manage wildlife reservoirs of zoonotic diseases; physical operations such as harvesting and the conversion of wildlife habitat to farmland; and the use of agrochemicals, particularly for pest control. While direct effects, such as accidental poisoning, tend to attract the most public attention, it is argued that indirect effects, such as the reduction in food supplies or the disruption of social structures, are likely to be of greater importance. The suffering of pest animals has traditionally been undervalued. There is a need for broader adoption of integrated, ecologically based strategies which minimise suffering and also minimise the numbers of animals involved by preventing population resurgence. New research is urgently required to compare the effects of alternative, economically viable farming strategies on both wildlife conservation and welfare, possibly within the framework of ecosystem services assessments.

Involuntary culling (IC) is where a cow is disposed of due to injury, poor health or infertility. The main reasons for IC are infertility, mastitis and lameness. These reasons have differing age profiles in when they affect cows, cost variable amounts to treat and have an effect on the value of the cow at market. They also reduce cow welfare in different ways. These factors influence the economically optimum cow replacement decision, which must balance the risks of future loss from the current cow against its future prospects and the net costs of a replacement. So the farmer's economic decision as to when to cull a cow may not occur at the same time as when the cow could, and sometimes should, be culled to maximise her welfare. To explore this dilemma, we developed a Dynamic Programme (DP) model to assess the optimum replacement policies for each of 180 possible cow states (12 parities and 15 milk-yield levels) under a simplified set of alternative husbandry systems and remedial practices. The DP was used to explore the relationships between financial outcomes, investment in improving welfare, lifespan and IC in dairy systems. There is a trade-off between dairy cattle lifespan and risk of suffering over which farmers have some control by the replacement and investment decisions they make. Our results show that improving cow welfare by reducing mastitis, lameness or infertility over the long term increases the mean longevity of the herd and also reduces the potential of long-term suffering resulting from chronic conditions. Additionally, it has the effect of increasing replacement opportunities and the annuities for each cow (£ per cow per year) mainly by increasing milk yield and reducing costly on-farm culls, creating a win-win situation for both farmer and cow.

The aim of this study was to assess the welfare of culled dairy cattle sent to an auction in the UK and identify associations between animal-based measurement and economic gain. The population of cull dairy cows sold at a Scottish livestock market were assessed on ten occasions for measures including body condition, mobility, hair loss and lesions, swelling, body cleanliness, claw conformation and total time in pre-sale pens. Details on breed, age, breeding status, farm, weight and price were gathered from market reports and cattle passports. Questionnaires sent to farms gathered information on reason for culling, retirement period (a finishing period to improve body condition), and number of lactations, among other variables. Measures such as bodyweight, breeding status, and breed type influenced price paid, with heifers and larger animals receiving higher prices. A negative effect over price paid was due to reduced mobility and hair loss scores, suggesting that some animal-based indicators of compromised welfare may be associated with a lower economic return from the cows sent to market. No influence of retirement length on price paid was noted. Reason for culling also did not influence price paid, but considering the association found between welfare and price paid, this suggests that the farmers’ reason for culling may not be necessarily revealed by the visual appearance of the cow. This study reveals reasons for culling and quantifies the welfare of dairy cows at market and demonstrates how measures of breeding status and body size, as well as measures of welfare, influence the buyers’ decisions and prices paid at auction.

The culling of injured and non-viable pigs (Sus scrofa) (neonate to breeding stock) is a routine and necessary procedure on most farms. Usually, pigs are culled using one of the following methods: blunt-force trauma (manual and mechanical), captive-bolt stunners, electrical stunning and electrocution or carbon dioxide. Manual blunt-force trauma is one of the most widely used methods due to its low or absent operational and investment costs. However, as a method, it has serious limitations, which include the risk of incomplete concussion, pain, and distress. Manual blunt-force trauma is also aesthetically unpleasant to operators and wider society. To address these issues there has been significant recent research into the development of alternatives to manual blunt-force trauma, these include: captive-bolt stunners, on-farm, gas-based controlled atmosphere systems, low atmospheric pressure systems and electrical stunning. Some of these are currently in commercial use while others are still in the developmental phase. This review brings together the relevant research in this field, evaluating the methods in terms of mechanism of action (mechanical and physiological), effectiveness and animal welfare.

The average productive lifespan is approximately 3 to 4 years in countries with high-producing dairy cows. This is much shorter than the natural life expectancy of dairy cattle. Dairy farmers continue to cull cows primarily for reasons related to poor health, failure to conceive or conformation problems prior to culling. These reasons may indicate reduced welfare leading up to culling. Improvements in health care, housing and nutrition will reduce forced culling related to these welfare reasons. However, productive lifespan has remained similar in decades, despite large improvements in cow comfort and genetic selection for the ability to avoid culling. On the other hand, genetic progress for economically important traits is accelerating within the last decade, which should slightly shorten the average economically optimal productive lifespan. A major driver of productive lifespan is the availability of replacement heifers that force cows out when they calve. The average productive lifespan could be extended by reducing the supply of dairy heifers, which would also have benefits for environmental sustainability. Improvements in culling decision support tools would strengthen economically optimal replacement decisions. In conclusion, major factors of the relatively short productive lifespan of dairy cows are welfare-related, but other economic factors like supply of heifers, genetic progress and non-optimal decision-making also play important roles.

Modelling wildlife disease poses some unique challenges. Wildlife disease systems are data poor in comparison with human or livestock disease systems, and the impact of disease on population size is often the key question of interest. This review concentrates specifically on the application of dynamic models to evaluate and guide management strategies. Models have proved useful particularly in two areas. They have been widely used to evaluate vaccination strategies, both for protecting endangered species and for preventing spillover from wildlife to humans or livestock. They have also been extensively used to evaluate culling strategies, again both for diseases in species of conservation interest and to prevent spillover. In addition, models are important to evaluate the potential of parasites and pathogens as biological control agents. The review concludes by identifying some key research gaps, which are further development of models of macroparasites, deciding on appropriate levels of complexity, modelling genetic management and connecting models to data.

A ratio-based logistic model developed to assess elephant harvest rates, based on a study at Nagarhole Tiger Reserve in India, was recommended as a management tool to control human–elephant conflict through culling. Considering this reserve among others violates an assumption of the logistic model: isolation. Nevertheless, assuming this violation was irrelevant, we re-evaluated the model, with minor modifications, for the neighbouring Mudumalai Tiger Reserve, where we used data from 13 elephant Elephas maximus population surveys to derive bootstrapped sets of population ratios, and mortality records. We generated arrays of harvest regimes and examined which ratio outputs were closest to the bootstrapped ratios. Our results indicated that (1) model outputs corresponded best with the Mudumalai population structure when harvest regimes were extreme and unlikely, (2) there were significant differences in population structure and harvest regimes between Nagarhole and Mudumalai, and (3) only 49% of adult male deaths predicted by model outputs were recorded in official governmental records. The model provides significantly different results among reserves, which invalidates it as a tool to predict change across the entire elephant population. Variability in survey data and inaccuracies in transition probabilities are sufficiently large to warrant caution when using them as a basis for deterministic modelling. Official mortality databases provide a weak means of validation because poaching incidents are poorly recorded. We conclude that the model should be based on validated transition probabilities and encompass the entire regional population.

The objective of this research was to evaluate the survival rate of primiparous heifers within a large sample of herds across the United Kingdom and specifically to assess the association between age at first calving (AFC) on their survival. Data from 437 herds were re-structured for analysis. Descriptive statistics were calculated, and a multilevel logistic regression model was used to explore factors associated with the risk of first lactation culling. Potential explanatory variables included AFC, herd size, culling rate within the whole herd, calving season, herd mean 305-day yield and herd mean calving interval. The mean within-herd culling rate for the primiparous heifers was 15.9%. The mean within-herd AFC was 29.6 months, with 35.9% of heifers having an AFC >30 months of age. Multivariable analysis revealed a negative association between survival rate of primiparous heifers and increasing AFC, and also associations with herd culling rate in older cows and calving season. This study highlights the importance of AFC for survival of primiparous heifers, as well as the need to address heifer wastage in herds with high culling rates.

This review examines methods for culling small numbers of poultry on farm, considering both common techniques and methods that are yet to be tested on poultry. The aim of this review is to inform the design of experiments that will assess the pros and cons of culling techniques. The methods reviewed include manual and mechanical cervical dislocation, crushing methods (such as burdizzos or pliers), percussive devices, blunt force trauma and a brain-stem piercing device. Previous work on these approaches, of which there is a limited dataset, has relied on behavioural and brain activity as proxy measures of unconsciousness (insensibility) and death, however there remains some uncertainty as to when birds can be considered unequivocally insensible. These factors will be considered when deciding which of the methods will be recommended to be taken forward for further assessment.

Lameness in sows is an emerging disease condition with major effects on animal welfare and economics. Yet the direct impact on reproduction results remains unclear. The present field study investigated the impact of lameness and claw lesions throughout the reproductive cycle on (re)production results of sows. In five farms, a total of 491 group-housed sows were followed up for a period of one reproductive cycle. Sows were assessed for lameness every time they were moved to another area in the farm. Claw lesions were scored at the beginning and at the end of the cycle. Reproduction results included the number of live-born piglets, stillborn piglets, mummified fetuses and crushed piglets, weaning-to-oestrus interval and the presence of sows not showing oestrus post weaning, returning to service and aborting. Sows that left the group were recorded and the reason was noted. A mean prevalence of lameness of 5.9% was found, although it depended on the time in the productive cycle. The highest percentage of lame sows (8.1%) was found when sows were moved from the post-weaning to the gestation stable. No significant associations were found between lameness and reproduction parameters with the exception of the effect on mummified foetuses. Wall cracks, white line lesions, heel lesions and skin lesions did have an effect on farrowing performance. Of all sows, 22% left the group throughout the study, and almost half of these sows were removed from the farm. Lameness was the second most important reason for culling. Sows culled because of lameness were significantly younger compared with sows culled for other reasons (parity: 2.6 ± 1.3 v. 4.0 ± 1.8). In conclusion, the present results indicate that lameness mainly affects farm productivity indirectly through its effect on sow longevity, whereas claw lesions directly affect some reproductive parameters. The high percentage of lame sows in the insemination stable indicate that risk factor studies should not only focus on the gestation stable, but also on housing conditions in the insemination stable.

The Goliath grouper Epinephelus itajara has been protected in the USA since 1990. In Florida commercial and recreational fishers consider the species a top predator of fish and lobster and advocate culling the grouper population as a solution to recover declining stocks. I examined the scientific evidence for and against culling the Goliath grouper, using commercial landing data from the National Marine Fisheries Service and the Florida Fish and Wildlife Conservation Commission (1950–2010), fisheries-independent diver-based surveys from the REEF Environmental Education Foundation (1993–2007), and published dietary and morphological studies. An analysis of the commercial extinction of the Goliath grouper in Florida indicates that its recovering population is not the cause of declining fish and lobster stocks. The recovering Goliath grouper population could provide ecological and socio-economic benefits: as top-down control on other lobster predators, in ecotourism, and as potential biocontrol of the invasive Indo-Pacific red lionfish Pterois volitans on Atlantic reefs.

Parasite-mediated apparent competition occurs when one species affects another through the action of a shared parasite. One way of controlling the parasite in the more susceptible host is to manage the reservoir host. Culling can cause issues in terms of ethics and biodiversity impacts, therefore we ask: can treating, as compared to culling, a wildlife host protect a target species from the shared parasite? We used Susceptible Infected Recovered (SIR) models parameterized for the tick-borne louping ill virus (LIV) system. Deer are the key hosts of the vector (Ixodes ricinus) that transmits LIV to red grouse Lagopus lagopus scoticus, causing high mortality. The model was run under scenarios of varying acaricide efficacy and deer densities. The model predicted that treating deer can increase grouse density through controlling ticks and LIV, if acaricide efficacies are high and deer densities low. Comparing deer treated with 70% acaricide efficacy with a 70% cull rate suggested that treatment may be more effective than culling if initial deer densities are high. Our results will help inform tick control policies, optimize the targeting of control methods and identify conditions where host management is most likely to succeed. Our approach is applicable to other host-vector-pathogen systems.

A study was undertaken to compare the longevity and lifetime lamb output of purebred Scottish Blackface (BF) ewes with a range of crossbred genotypes from Scottish BF dams. For up to five successive breeding seasons, 1143 Scottish BF, Swaledale × BF (SW × BF), North Country Cheviot × BF (CH × BF), Lleyn × BF (LL × BF) and Texel × BF (T × BF) ewes were mated to a range of sire breeds on six hill farms across Northern Ireland. Dentition and lamb output were recorded annually until completion of the study or until the ewe was removed due to death or culling. Timing of mortality and the main reason for culling were also recorded. When survival analysis was undertaken, SW × BF and CH × BF ewes had better longevity (P < 0.05) than BF ewes due to their lower culling rate (P < 0.01) and lower mortality rate (P = 0.06), respectively. The relative proportion of LL × BF and T × BF culled due to infertility was lower (P < 0.05) than SW × BF and CH × BF, while a higher (P < 0.05) proportion of LL × BF and T × BF ewes were culled for prolapses compared with the other breed crosses. SW × BF ewes had consistently higher bite scores (P < 0.001) compared with BF, LL × BF and T × BF, indicating a greater prevalence and degree of overshoot. In ewes aged 5.5 years old, SW × BF also had a higher incidence of tooth loss (P < 0.01) compared with the other breeds. However, the proportion of SW × BF culled due to poor teeth condition was lower (P < 0.05) than BF. Across all breeds, the chances of surviving to their next mating were influenced by ewe breed (P < 0.05), age at mating (P < 0.001), body condition score at weaning (P < 0.001), number of missing teeth (P < 0.001) and average daily live weight gain per litter (P < 0.05). The cumulative number and weight of lambs weaned per ewe over five successive matings was higher (P < 0.05) for crossbred compared with pure BF ewes; however there were no differences in lifetime output between the different crossbred ewes studied. This study demonstrates that the higher lamb output of crossbred hill ewes does not compromise their longevity compared with pure Blackface, resulting in greater total lifetime production. When the crossbred ewes are sired by a second hill breed, longevity may be improved.

The 2006 Highly Pathogenic Avian Influenza (HPAI) outbreak in Egypt saw the adoption of a fierce stamping-out policy with the culling of 30 million birds in a matter of weeks. This was coupled with an ad hoc compensation scheme that led to wide misuse and rapid depletion of allocated funds. Since September 2006, no compensation has been paid.

HPAI in Egypt is now believed to be endemic and a comprehensive, transparent and fair compensation policy is needed to encourage disease reporting. With or without compensation, rehabilitation of the poultry producing units will occur. Strong veterinary engagement in the start up activities of small producers could be a means to improve biosecurity and establish trust. This paper outlines FAO's activities related to an extensive exercise undertaken to support the government of Egypt in formulating and implementing a compensation policy and strategy, which ensures that poor backyard poultry producers (usually women) are fairly compensated; and an investigation into how smallholder poultry producer rehabilitation activities are currently operating and how these activities can be supported.