Electric Prod Research Articles

Developing measures to audit welfare of cattle and pigs at slaughter

AbstractSince 1999, animal welfare auditing programmes that utilise five numerically scored core criteria have been used successfully by major restaurant chains to monitor animal welfare in slaughter plants. They had to achieve specific numerical scores in order to remain on the approved supplier list. The five numerically scored criteria (critical control points) are: i) Percentage of animals that fall down during handling; ii) Percentage of animals moved with an electric prod; iii) Percentage of cattle or pigs vocalising in the stunning box or restrainer; iv) Percentage of animals stunned effectively with one application of the stunner; and v) Percentage rendered insensible when hoisted to the bleed rail (has to be 100% to pass the audit). Audit data collected in 2010 by two restaurant companies in 30 beef plants, indicated that 77% of them effectively stunned 100 to 99% of the cattle with a single shot from a captive-bolt gun. All 30 plants passed the audit, which required 95% of more of the cattle stunned with one shot. In eight pork plants with electric stunning, the tongs were placed correctly on 100% of the pigs held in a V-conveyor restrainer. In 95% of the beef plants, and 86% of 25 pork plants, 0% of the animals fell during unloading, movement in the lairage and during handling in the stunning area. In 81% of the beef plants and 77% of the pork plants, 5% or less of the animals were moved with an electric prod. The percentage of cattle vocalising in the stun box and during movement into the stun box was 3% or less in all the plants except one. All scores are per animal, an animal is stunned correctly in the first shot, or not stunned correctly. It either vocalises or it is silent. A passing score is required on all five of the numerically scored core criteria. Due to financial and time constrains, the same auditor assesses both welfare and food safety. Workshops for training auditors last 1.5 days and include two plant visits.

The journey to slaughter for North American horses

Implications • The role of the horse has been diverse in North America during the last century, including slaughtering horses for meat products intended for human consumption. Although horse meat is not culturally preferred in the diets of Americans and most Canadians, it is an acceptable meat source in the diet of Mexicans. The peak in the number of horses slaughtered in North America occurred in the 1980s, with as many as 350,000 horses per year. Over 90% of these horses were processed in the US, with the resultant meat products exported overseas. • Public concern grew in the 1990s in the US on the alleged conditions of handling, transport, and slaughter of horses. Welfare concerns were focused on the utilization of the double-deck trailers, long transit duration without feed or water, use of an electric prod, and lack of provisions for injured, pregnant, old, or very young horses. This societal pressure promulgated the development of federal regulations on the safe and humane commercial transport of equines to slaughter. However, by the end of 2007, the last three processing plants in Texas and Illinois were closed due to state and federal laws. • Closure of the processing plants precipitated a dramatic increase in the number of US-origin horses transported to slaughter plants in Canada and Mexico. With this shift in destination, welfare of the horses was compromised by increased duration of transport, inspection processes at the US borders, and the handling and stunning at slaughter facilities, especially in Mexico. Guidelines, regulations, and assessment tools for welfare of slaughter horses have been developed and implemented in Canada. • The number of “unwanted” and neglected horses has increased in the US with the closure of the processing plants. The existing rescue and rehabilitation facilities in operation throughout the US do not meet the needs to care for these horses due to limited capacity and funding. • Major challenges in the future sustainability of the industry will depend on several factors including the cultural preference for horse meat in the diet, the public’s concern for the care and handling of horses during transport and slaughter, the impact of additional regulations, and the continued availability in the supply of horses, particularly those originating from the US.

Loading gantry versus traditional chute for the finisher pig: Effect on welfare at the time of loading and performance measures and transport losses at the harvest facility1

The objectives of these studies were to evaluate the loading system effects [traditional chute (TC) vs. prototype loading gantry (PLG)] on i) welfare measures at loading and ii) performance measures and transport losses at the harvest facility for the market-weight pig (Sus scrofa). This study compared first pull (FP), which was the first group of pigs, and close out (CO), which was the last group of pigs marketed from a finishing facility. Experiment 1 evaluated 74 loads for welfare measures at loading on the farm, and Exp. 2 evaluated 497 loads for performance measures and transport losses at the harvest facility. Data were analyzed using the PROC Mixed procedure for Exp. 1 and PROC GLIMMIX procedure of SAS for Exp. 2. In Exp. 1, pigs loaded using the PLG had fewer (P × 0.0002) electric prod touches, slips, falls, vocalizations, and pile ups compared with pigs loaded on the TC during FP and CO. In Exp. 2, there were no (P > 0.05) differences for any performance measures between loading systems or by pull. Pigs loaded using the prototype PLG loading gantry experienced fewer (P = 0.03) total transport losses than pigs loaded using the TC in the FP. In conclusion, the prototype loading gantry improved all welfare measures at the time of loading and reduced overall total transport losses. These studies demonstrate that loading systems that improve on-farm swine welfare at loading and reduce transport losses at the harvest facility can be designed.

Invited review: Effects of lairage and slaughter conditions on animal welfare and pork quality

Besides creating a reservoir of animals aimed at maintaining the constant speed of the slaughter line, the function of lairage is to allow the animals to recover from the stress of transport and unloading. However, inadequate treatment of slaughter pigs in this stage or lack of environmental control may result in additional stress leading to economic losses due to poor animal welfare (deads-on-arrival and downers), skin damage and poor meat quality. Short and long lairage times can result in increased incidences of pale, soft, exudative and dark firm, dry pork, respectively. However, these effects are influenced by the environmental conditions and the pig genotype. Mixing unfamiliar pigs increases skin damages due to fighting, but keeping pigs in small groups or at high stocking density may limit this effect. Research is needed to identify alternative tools to the electric prod and to design a stunning chute enabling a smooth flow of pigs into the stunner.

Effects of different moving devices at loading on stress response and meat quality in pigs1

Although there is increasing evidence regarding the negative welfare and meat quality implications of electric prod use for slaughter-weight pigs, this handling tool continues to be used. Therefore, the behavioral and physiological response and carcass and meat quality of 360 pigs being loaded onto a truck for transportation to slaughter according to 3 handling procedures were studied. The 3 handling procedures were 1) moving with an electric prod and board from the finishing pen to the truck (EP); 2) moving with a board and a paddle from the finishing pen to the truck (PAD); 3) moving with a board and a paddle from the finishing pen and using a compressed air prod in the ramp before going into the truck (CAP). A subpopulation of 144 pigs (48 pigs/treatment) was equipped with heart rate monitors. Blood samples were collected from the same animals at exsanguination for the analysis of creatine phosphokinase and lactate. Data were analyzed using an ANOVA for factorial design, with the animal as the experimental unit. Behavior was analyzed with MIXED model procedure with treatment as a fixed effect. During loading, EP pigs slipped and fell (P < 0.001) and overlapped (P = 0.03) more often, but stopped (P < 0.001) and attempted turns (P = 0.01) less often than CAP or PAD. With CAP, pigs made more 180° turns (P = 0.01) than with PAD or EP. Loading with EP led to more and longer vocalizations (P = 0.02 and P = 0.001, respectively) than loading with CAP or PAD. Loading took longest with CAP and was quickest with EP (P = 0.01). Pigs handled with EP had a greater heart rate than those moved with PAD and CAP at loading (P < 0.001), wait at loading (P < 0.001), at unloading (P = 0.05), and in lairage (P = 0.02). Pigs loaded with EP had greater (P = 0.05) lactate concentrations in blood at exsanguination compared with pigs handled with CAP, with pigs loaded with PAD being intermediate. Furthermore, ultimate pH values in the semimembranosus and adductor muscles of EP pigs were greater (P = 0.002 and P = 0.004, respectively) compared with those from PAD and CAP pigs. Greater (P = 0.04) incidence of blood-splashed hams was found in EP pigs compared with PAD and CAP pigs. Therefore, considering animal welfare, carcass bruising, and blood splashes standpoints, EP should be replaced with PAD or CAP. However, additional research is necessary to identify methods that improve the loading efficiencies of PAD and CAP without adversely affecting animal welfare parameters.

Transportation of beef cattle to slaughterhouses and how this relates to animal welfare and carcase bruising in an extensive production system

AbstractThe objective of this study was to evaluate conditions during transport and their effects on welfare and carcase bruising of beef cattle in Uruguay, a country with an extensive, pasture-based, production system. Twelve abattoirs were visited periodically during two years (2002-2003) and 448 trucks were inspected on arrival. The state of vehicle maintenance was deemed ‘unacceptable’ for the transport of animals in 16.5 (± 3.2)% of cases and most of the vehicles (99.1 [± 0.1]%) had a ‘guillotine-type’ door at the rear end. Both characteristics showed a significant association with the presence of carcase bruising. No overall significant difference was found with the year of vehicle manufacture (24.6 [± 0.2]% before 1990), the presence of rollers bars in 51.3 (± 0.1)% of the trucks on one or both sides of the doors, and the working experience of the men who transported the cattle (&gt; 10 years). The average distance travelled with the animals loaded onto trucks was 240 (± 9) km and the mean journey length was 305 (± 7) min (5 h). A statistically significant effect of the distance travelled and the state of the roads on the occurrence of bruising was found. The use of devices to force animals to move, such as: electric prod (75%), sticks (3%), loud shouts (40%) and a combination of all of the above were positively correlated with bruising. After slaughter, carcase bruising was identified, quantified, and classified into three degrees of muscle injury. From 15,168 beef cattle observed, 60.0% (9,106) had at least one injury. Of the injured carcases, 33.1% (3,015) had one bruise, 25.1% (2,289) had two bruises, 16.2% (1,474) had three bruises and 25.6% (2,328) four or more bruises. Transporting animals in a humane fashion will reduce the amount of bruising on carcases, thereby increasing both the welfare of beef cattle and the profitability of the beef industry in Uruguay.

Effect of unloading, lairage, pig handling, stunning and season on pH of pork

A total of 12,725 pigs originating from 90 transports were followed up at 17 Belgian commercial slaughterhouses. The effects of several pre-slaughter parameters concerning transport, unloading, lairage, pig handling, stunning and season on fresh meat quality based on pH measurements 30 minutes (min) after slaughter were investigated. Meat quality was measured on 4285 pigs. Ten pre-slaughter parameters had a significant effect on meat pH after separate introduction of the variable as a fixed effect in the model. Simultaneous analysis of these variables in the global model revealed that the pH was influenced by four main risk factors, namely the mean noise level produced during unloading, the percentage of panting pigs, the use of an electric prod and season. Meat quality in terms of the percentage of potentially PSE carcasses was better in summer than spring or autumn and could be explained by a lower observed pre-stunning stress in summer.

Use of exsanguination blood lactate to assess the quality of pre-slaughter pig handling

The objective of these studies (Exp.1, n=76; Exp.2, n=140) was to characterize the relationship of pre-slaughter animal-handling events to exsanguination blood lactate concentration ([LAC]) in a commercial pork processing plant. Pearson correlations indicated relationships (P<0.05) between [LAC] and the number of times a pig jammed, backed up and reared (Exp.1), and [LAC] was correlated (P<0.05) with electric prod use and vocalization in response to prod use in the crowd pen, as well as jamming in the single-file chute (Exp. 2). Single degree of freedom contrasts indicated that pigs experiencing one or more events (i.e., jamming, rearing and/or backing up) while moving through a single-file chute had greater (P<0.03) [LAC] than pigs that did not experience these events in both experiments, whereas pigs prodded in the crowd pen had greater (P=0.03) [LAC] than pigs that were not prodded (Exp. 2). This study provides data demonstrating that specific pre-slaughter animal-handling events are related to post-slaughter [LAC] in a commercial setting.

Infrared thermography as a non-invasive method for detecting fear-related responses of cattle to handling procedures

AbstractTwo experiments were conducted to determine whether maximum eye temperature, measured using infrared thermography (IRT), could be a non-invasive technique for detecting responses of cattle to handling procedures. Experiment one used six crossbred heifers randomly assigned to two groups in a crossover design and subjected to i) being hit with a plastic tube on the rump and ii) being startled by the sudden waving of a plastic bag. Experiment two used 32 crossbred bulls randomly assigned to three treatments: i) control, restraint only; ii) electric prod, two brief applications of an electric prod or, iii) startled, as in experiment one, accompanied by shouting. Exit speed (m s−1) was recorded on release from the restraint. Maximum eye temperature was recorded continuously pre- and post-treatment. In experiment one, eye temperature dropped rapidly between 20 and 40 s following both treatments and returned to baseline between 60 and 80 s following hitting and between 100 and 120 s following startling. In experiment two, eye temperature dropped between 0 and 20 s, following both treatments, and returned to baseline by 180 s, following startling plus shouting, but did not return to baseline for five minutes following electric prod. Exit speed tended to be faster following the electric prod. In conclusion, IRT detected responses that were due possibly to fear and/or pain associated with the procedures and may therefore be a useful, non-invasive method for assessing aversiveness of handling practices to cattle.

The effects of handling and group size on welfare of pigs in lairage and their influence on stomach weight, carcass microbial contamination and meat quality

At unloading and on the way to stunning, 800 barrows were exposed to either gentle handling (GH: slowly with a plastic board or whip) or rough handling (RH: quickly with an electric prod). Pigs were kept in large or small groups (30 or 10 pigs) during lairage. Compared with GH, RH increased climbing (P &lt; 0.05), slipping (P &lt; 0.01) and turning around (P &lt; 0.001) behaviours during unloading, and climbing (P &lt; 0.05) on the way to stunning. RH also reduced drinking behaviour during lairage (P &lt; 0.01). Pigs kept in large groups were observed more often standing (P &lt; 0.05) and fighting (P &lt; 0.001) than pigs kept in small groups, but, in contrast, had a slightly lower level of urinary cortisol at slaughter. Stomach weight and microbial contamination at slaughter were not affected by treatments. RH tended to increase skin bruise score on the carcass (P &lt; 0.06) and produced more exudative meat (P &lt; 0.05). In conclusion, the response of pigs to the two specific stressors applied prior to slaughter in this study did not seem to contribute to stomach weight variation at slaughter, but it did influence pork quality. Key words: Pigs, pre-slaughter handling, group size, stress, stomach weight, microbial contamination, behaviour, meat quality

Use of supplementary tryptophan to modify the behavior of pigs1

Three experiments were conducted to investigate the short-term use of supplementary Trp on the behavior of grow/finish pigs. Three levels of dietary Trp were used, representing the standard requirement for growth (control), twice (2x), and 4 times (4x) the control amount. In Exp. 1, pigs were fed the diets for 7 d, during which observations were made of their general behavior (time budget), aggression within the group of familiar pigs, and response to a startling auditory stimulus. Behavior effects were evident during the period of supplementation for both the 2x and 4x diets. During the treatment period, pigs fed supplemental Trp spent more time lying (P = 0.04) and less time eating (P = 0.05) than pigs fed the control diet. Although the response of the animals to the startling stimulus was to become alert and stand, similar behavioral effects caused by supplemental Trp also were evident after the startling stimulus (P < 0.01). Based on these observations, the subsequent studies retained the same dietary levels of Trp and incorporated a 3-d feeding of diets before behavior testing. In Exp. 2, pigs were fed the experimental diets for 3 d before being regrouped with unfamiliar pigs on the same diet. Subsequent aggression was affected by Trp supplementation, in that high levels of dietary Trp decreased the total duration of fighting by approximately 50% (P = 0.03). Supplemental Trp had no effect on the number of fights, and there were no differences between the 2 levels of supplemental Trp on any behavior. In Exp. 3, pigs were exposed to specific handling tests on the farm and meat quality assessments after being fed the experimental diets for 3 d. There were no differences among dietary treatments for any of the meat quality characteristic variables measured. The only behavioral or physiological difference observed among the treatments was a slower movement of pigs fed the 4x Trp treatment than control or 2x Trp-fed pigs in a minimal-forced situation (P = 0.04). Response to confinement on a scale, an electric prod, and movement in general did not differ among treatments. High levels of Trp may result in animals avoiding stressful situations if possible, but they seem to have no effect on responses to stressors that animals may experience in a forced situation.

Maintenance of good animal welfare standards in beef slaughter plants by use of auditing programs

The public has become increasingly concerned poor about farm animal welfare. Although all veterinarians do not work with farm animals, it is important that all can answer questions on that subject from their clients or others. One area of concern is how animals are treated at slaughter plants. Many people are not aware that restaurant companies have been auditing animal welfare in slaughter plants since 1999. This has resulted in great improvements in cattle handling and stunning. The McDonald's Corporation started their animal welfare auditing program in 1999. Wendy's International and Burger King Corporation began their programs in 2000 and 2001, respectively. The author worked with all 3 companies on the implementation of their programs. Restaurant companies use their own auditors (who visit the plants routinely for food safety audits) to perform their welfare audits. During the last 5 years, the author has worked with McDonald's Corporation, Burger King Corporation, and Wendy's International to train foodsafety auditors to score each slaughter plant for animal welfare by use of an objective numerical scoring system 2,3 . Instead of relying on a subjective assessment, the auditor counts the percentage of cattle that was correctly stunned with 1 shot, percentage moved with an electric prod, and percentage that vocalized (moo or bellow) during handling and stunning. Vocalization is associated with blood cortisol concentrations in cattle 4 . A previous study 5 revealed that 98% of the cattle that vocalized during handling and stunning in a slaughter plant had vocalizations that were associated with an obvious aversive event, such as nonfatal attempts at stunning, slipping, use of electric prods, contact with sharp metal edges, or excessive pressure from a restraint device.

Effects of dietary supplementation with L-carnitine and fat on blood acid–base responses to handling in slaughter weight pigs1

Blood acid-base responses to handling were evaluated in slaughter weight pigs fed diets supplemented with l-carnitine and fat. The study was carried out as a randomized block design with a 2 x 2 factorial arrangement of treatments: 1) dietary L-carnitine supplementation (0 vs. 150 ppm, as-fed basis); and 2) dietary fat supplementation (0 vs. 5%, as-fed basis). Sixty pigs (91.1 +/- 5.14 kg BW) were housed in mixed-gender groups of five and had ad libitum access to test diets (0.68% true ileal digestible lysine, 3,340 kcal of ME/kg, as-fed basis) for 3 wk. At the end of the feeding period (110.3 +/- 7.52 kg BW), pigs were subjected to a standard handling procedure, which consisted of moving individual animals through a facility (12.2 m long x 0.91 m wide) for eight laps (up and down the facility), using electric prods (two times per lap). There was no interaction between dietary L-carnitine and fat supplementation for any measurement. Pigs fed 150 ppm of supplemental L-carnitine had lower baseline blood glucose (P < 0.05) and higher baseline blood lactate (P < 0.05) concentrations than the nonsupplemented pigs. After handling, pigs fed L-carnitine-supplemented diets had a higher (P < 0.05) blood pH and showed a smaller (P < 0.05) decrease in blood pH and base excess than those fed the nonsupplemental diets. Baseline plasma FFA concentrations were higher (P < 0.01) in pigs fed the 5% fat diet. After the handling procedure, blood glucose, lactate, and plasma FFA were higher (P < 0.05) in pigs fed the 5 vs. 0% fat diets, but blood pH, bicarbonate, and base excess were not affected by dietary fat. The handling procedure decreased (P < 0.01) blood pH, bicarbonate, base excess, and total carbon dioxide and increased (P < 0.01) blood lactate, partial pressure of oxygen, and glucose, and also increased (P < 0.01) rectal temperature. Free fatty acid concentrations were increased by handling in pigs fed both 0 and 5% fat and 150 ppm L-carnitine. In conclusion, dietary L-carnitine supplementation at the level and for the feeding period evaluated in the current study had a relatively small but positive effect on decreasing blood pH changes in finishing pigs submitted to handling stress; however, dietary fat supplementation had little effect on blood acid-base balance.

Moving Devices for Finishing Pigs: Efficacy of Electric Prod, Board, Paddle, or Flag

A total of 320 finishing pigs (72 to 90 kg) was used in four studies to assess the efficacy of various moving devices by evaluation of pig behavior and time to complete a standardized course. The handler was behind the pigs (n = 3) with the objective of moving the pigs forward. In the first study, pig reactions to an electric prod or paddle touching their ham, neck, rear hock or back, or on their left or right side were recorded. The percentage of pigs moving forward was greatest (P<0.05) when pigs were touched on their back. Future work standardized touching pigs on their back to get them to move forward. In the second study, paddles colored blue, red, or green were found equally effective (P>0.05) at moving pigs. Studies then standardized evaluations using blue devices. In the third study, the electric prod, paddle, and board were evaluated for time to complete the course. A handler using a board required less time (P<0.05) to move pigs compared with an electric prod or paddle. Pig vocalization was similar after being touched with either the paddle or electric prod, but these devices caused more pig vocalization than the board (P<0.05). In the fourth study, the board was compared with a flag. The board and flag were statistically equal in time required to move pigs through the course. In conclusion, the board was the most efficacious moving device among those evaluated.

The relationship between beliefs, attitudes and observed behaviours of abattoir personnel in the pig industry

Previous research has indicated that frequent use of aversive pig handling techniques by stockpeople prior to slaughter, in particular the use of an electric prod, results in poorer welfare and reduced meat quality. The aim of this study was to investigate the role of attitudes in the prediction of behaviour of abattoir stockpeople. Twenty-four male employees at a large commercial piggery, working in the lairage area where pigs are slaughtered, participated in the study. Stockperson attitudes and personality were assessed using self-report questionnaires, and behaviour was assessed directly with the use of trained observers. A key finding of this study was that positive attitudes, both general and behavioural, were associated with use of an electric prod with the power turned off (NPROD) while negative attitudes were associated with use of the prod with the power on (PROD). This suggests that NPROD is actually intended to be a benign interaction by the stockperson when there is a need to move a pig but the stockperson wishes to avoid aversive interactions. On the other hand, PRODs can be interpreted as intended negative interactions. It was concluded that a simplified model based on Ajzen’s theory of planned behaviour applies in this situation because neither perceived control nor normative beliefs moderate the relationship between attitudes and behaviour in this context. The investigation of the role of personality factors in predicting abattoir stockperson behaviour yielded one significant factor: tough-mindedness. If it can be shown that modifying stockperson attitudes and behaviour leads to improved meat quality, then there is an opportunity to develop training programs to improve stockperson attitudes and behaviour in abattoirs, with subsequent improved pig welfare and meat quality.

Device for handling livestock using vibration and noise as a stimulation on external portions of the body

A battery operated hand held device for use in handling or controlling livestock, particularly cattle, swine, sheep and horses. This invention provides a novel alternative to conventional electric livestock prods, which deliver an electric shock to the animal. While operating on the principle of external stimulus to invoke a flight response, this invention relies on vibration and/or sound rather than painful electric shock. This unique mode of action satisfies the needs in the livestock industry for low stress handling equipment and techniques with the welfare of the animal as a priority.

INCREASE IN ACOUSTIC DETECTABILITY OF PLODIA INTERPUNCTELLA (LEPIDOPTERA: PYRALIDAE) LARVAE IN STORED PRODUCTS AFTER ELECTRICAL STIMULATION

Modern computer and electronic technology has enabled the development of powerful acoustic methods for detection of hidden insect infestations in stored products (e.g., Shade et al. 1990, Shuman et al. 1993, 1997; Pittendrigh et al. 1997), wood (Scheffrahn et al. 1993, 1997), and soil (Mankin et al. 2001). Despite their power, the utility of acoustic tools for detecting insect infestations is limited under conditions of reduced activity such as low temperatures (Maier et al. 1996), molting or pupation (Vick et al. 1988, Pittendrigh et al. 1997), and after disturbance, depending on the species (Mankin et al. 1999, Miyatake 2001). Even under optimal temperatures, stored product insect larvae are quiet in 1030% of 5-minute monitoring periods during growth phases (Vick et al. 1988), and quiescent periods can extend from 3-5 minutes after a disturbance (Miyatake 2001) to >8 h during molting phases (Pittendrigh et al. 1997). The reliability of acoustic surveillance would be improved if effective excitatory stimuli could be applied to inactive insects just before monitoring, particularly if the excitation increased the loudness of the sounds produced. One potential use of acoustic technology that remains largely undeveloped is nondestructive surveying for insect infestations in packaged goods. Plodia interpunctella (Huibner) is a major pest of packaged goods in warehouses and retail stores (Arbogast et al. 2000) and early detection of larvae in packages could reduce high-value product losses and eliminate the buildup of populations. However, the weak sounds produced by 3rd-4th instar (5-15 mg) P interpunctella larvae are difficult to detect through multiple layers of protective packaging. The detectability of these larvae could be improved if artificial stimuli were available to increase the rate and loudness of larval sounds during acoustic monitoring periods. Treatments used previously to stimulate insect activity and increase their visual or acoustic detectability include heat (Shade et al. 1990, Hagstrum and Flinn 1993, Au 1997, Mankin et al. 1999), disturbance, usually of highly mobile species (Minnich 1936, Masters 1979, Roces and Manrique 1996), and electrical stimulation (Vander Meer et al. 1999). Heat has been used in Berlese funnels and related devices (e.g., Edwards 1991) but its activating effects are indirect and may take hours to develop. Electrical stimulation is used to control activity of farm animals but rarely of insects. In a high-school student research project conducted by Brett Miller, 4th-instar P. interpunctella larvae were monitored to determine if commercially available electrical stimulation tools increased larval activity levels and acoustic detectability. Individual larvae were placed on dog food biscuits 1-2 days before testing and kept in separate containers. Stimulation was applied by placing an infested biscuit between the two prongs of an electric prod (Model Sabre Six, HotShot Products, Inc., Savage, MN) (9 kV, 19 mA) and then briefly toggling the actuator. The prongs were 3.5 cm apart and the biscuits were -2.5 cm wide. For control tests, the prod was inactivated by removing its battery pack. Acoustic monitoring was performed by placing each infested biscuit on a 4.5-cm-diameter piezoelectric disk (MuRata Erie model PKM28-2AO, Smyrna, GA) (see Mankin et al. 2000). Sounds generated by moving and feeding larvae were monitored for 180-s periods at 24-26?C in an acoustically shielded chamber (Mankin et al. 1996). On 3 different weeks (blocks), recordings were obtained from larvae in 20 biscuits treated with an active prod and 20 biscuits treated with an inactive prod (120 larvae altogether). Monitoring was done immediately before the biscuit was placed between the electrodes, immediately after the activation treatment, and 10 minutes later to consider the duration of stimulatory effects. The acoustic signal collection and analysis procedures were similar to those described in Mankin et al. (2001). A noise threshold was set at a level that eliminated low-level, extraneous sounds. At this threshold, no sound pulses were registered in control tests with uninfested biscuits, with or without electrical stimulation. A spectral profile of P interpunctella sounds was calculated from averages of 20-50 pulses collected during a noise-free period of recording, and signals above the noise threshold that matched this profile were counted as larval sound pulses using a custom-written computer program, DAVIS (Mankin 1994). Because this study was conducted in an acoustically shielded anechoic chamber, the recordings contained minimal noise and almost all of the sound pulses matched the larval profile. Background noise is prevalent in field studies but insect profiles can be used to screen out all but a small percentage of background noises (Mankin et al. 2000, 2001). A treatment that stimulates increased activity is of most benefit for acoustic detectability when

Cattle vocalizations are associated with handling and equipment problems at beef slaughter plants

Vocalization of cattle in commercial slaughter plants is associated with observable aversive events such as prodding with electric prods, slipping in the stunning box, missed stuns, sharp edges on equipment or excessive pressure form a restraint device. A total of 5806 cattle were observed during handling and stunning in 48 commercial slaughter plants in the United States, Canada and Australia during the calendar year of 1999. Each animal was scored as either a vocalizer or a non-vocalizer. In 20 plants (42%), 0–1% of the cattle vocalized, in 12 plants (25%) 2–3% vocalized, in 12 plants (25%) 4–10% vocalized and in four plants (8%) more than 10% vocalized. In three plants repeated use of an electric prod on 95% or more of the cattle that balked and refused to move was associated with vocalization percentages of 17, 16 and 12%. In five plants, the percentage of cattle that vocalized was reduced by making modifications to plant equipment. Reducing the voltage on a rheostat controlled electric prod reduced the vocalization percentage from 7 to 2% in the first plant. In three other plants, the incidence of cattle backing up and balking was reduced by illuminating a dark entrance or adding a false floor to a conveyor restrainer. A false floor eliminates the visual cliff effect. The percentage of cattle that vocalized was reduced from 8 to 0%, 9 to 0% and 17 to 2%. Since balking was reduced, electric prod use was also reduced. In the fifth plant, reduction of the pressure exerted by a neck restraint reduced the percentage of cattle that vocalized from 23 to 0%. In the five plants where modifications were made, a total of 379 cattle were observed prior to equipment modifications and 342 after modification. The mean percentage of cattle that vocalized was 12.8% before the modifications and 0.8% after the modifications ( P<0.001). Vocalization scoring can be used to identify handling and equipment problems that may compromise animal welfare.

Aversion learning techniques to evaluate dairy cattle handling practices

Fear of humans is a source of stress for Holstein dairy cattle and can result when animals are handled aversively. We used aversion learning techniques to determine which handling practices cattle find most aversive. In an aversion race, the cows are repeatedly walked down a race and treatments applied when they reached the end; the time and force required for cows to walk down the race are measured. The animal learns to associate walking down the race with the treatment received; if the treatment is aversive, the animal will take more time and require more force to reach the end of the race than if the treatment is positive. In experiment 1, 54 cows were assigned to four treatments (hit/shout, brushing, control, and food). Treatments of 2-min duration were applied three times a day for 4 days. Cows on the hit/shout treatment took more time and required more force to walk through the race than cows on other treatments, while brushed cows took longer to move through the race than cows given food. In experiment 2, 60 cows were assigned to five treatments (electric prod, shouting, hitting, tail twist, and control). Treatments of 1-min duration were applied three times a day for 3 days. Cows on the shout and electric prod treatments took more time and required more force to walk down the race than cows on the control treatment. In experiment 3, thirty-six 1–1.5-year-old heifers were assigned to three treatments (hand feeding, gentling, or control) applied as in experiment 2. Treatments did not affect the time or force required to walk down the race. The aversion race successfully discriminated between handling treatments that differ greatly in aversiveness but lacked sensitivity to distinguish between treatments that were similar. Although many procedural factors must be considered, aversion learning techniques are an effective method to determine which handling practices cattle find aversive or rewarding.

Effects of handling aids on calf behavior

Effects of three different handling aids on calf behavior were determined. Group 1 calves were intensively-reared intact Holstein males (mean 180 days old); Group 2, extensively-reared beef-breed females (mean 230 days); Group 3, extensively-reared castrated beef-breed males (mean 253 days). Calves in each group were assigned to one of three handling aid treatments ( n=5 per treatment subgroup; total n=45): electric prod (Prod), oar with rattles (Oar), manual urging (Manual). Treatments were applied only as needed to encourage forward movement of calves through the length of a solid-sided semicircular chute system. Number of treatment applications, length of time required to move through the entire chute system, and behavior during movement through the chute were recorded. An approach test was conducted 1 day before and 1 day and 1 week after chute tests to evaluate changes in behavior due to handling aid application. During chute tests, Group 1 Prod calves required the fewest treatment applications (4.9) vs. 23.5 (Oar) or 13.5 (Manual), ran most often (1.40 times) vs. 0.20 times (Manual) or 0.33 times (Oar), and made contact with chute sides most often (1.8 times vs. 0.2 times (Manual) or 0.7 times (Oar), respectively (all P<0.05). Similar trends were observed for calves in Groups 2 and 3. There were no significant differences between behaviors observed during the approach tests conducted before and after handling aid treatments had been imposed. Regardless of treatment, intensively-reared Group 1 calves appeared markedly less fearful of handlers during approach tests compared to extensively-reared calves in Groups 2 and 3, which demonstrated overt attempts to escape from the test facilities. One week after chute tests, 13 of 15 Prod calves from all three groups walked, rushed, or backed >1 m away from the handler when the prod was buzzed but not applied, suggesting that the buzzing sound alone may have sufficed to encourage movement by calves that had previously experienced both the sensation and sound associated with electric prodding.