The efficacy of three on-farm euthanasia methods for broiler chickens throughout the production cycle.

1. There is a need to humanely kill moribund or injured broiler birds on-farm with no reasonable chance of recovery. Two experiments evaluated the efficacy of three commercially applicable killing methods; manual cervical dislocation (CD), mechanical cervical dislocation with the Koechner Euthanising Device (KED) and a non-penetrative captive bolt device (Zephyr-EXL; ZEXL), at 7, 21 or 35 d of age, on their ability to induce insensibility (unconsciousness and loss of brain stem reflexes) and death.2. Experiment one assessed the damage to the cranial-cervical region resulting from the methods applied to cadavers of cull birds (n = 180) by radiography and gross pathology observation.3. Experiment two evaluated the latency to insensibility and death when cull broiler birds (n = 240) were killed by CD, KED or ZEXL, using behavioural and reflexive indicators. Insensibility and death were measured by the absence of pupillary light, palpebral blink and nictitating membrane reflexes and cessation of rhythmic breathing, cloacal winking and convulsions. Analysis of variance for the main effect of the method was performed to determine the differences.4. In experiment one, only the Zephyr resulted in skull fractures. A higher number of vertebral fractures occurred with KED application compared to CD, at 21 and 35 d.5. In experiment two, indicators of sensibility were absent earliest with the ZEXL (µ < 2 s); then,CD (µ = 28 s) and were longest with KED (µ = 47 s), at 21 and 35 d. Cloacal winking and convulsions ceased earlier after CD (88 s), compared to either KED (124 s) or Zephyr (118 s). Death after a single application occurred 100%, 100% and 98% of time for CD, KED and ZEXL, respectively.6. Overall, all methods were efficacious at inducing insensibility and death. Insensibility occurred earliest with ZEXL, whilst death occurred earliest with CD. KED resulted in the longest time to insensibility and death.

Assessing the effect of water deprivation on the efficacy of on-farm euthanasia methods for broiler chickens.

1. Moribund or diseased poultry requiring euthanasia are often dehydrated. To understand how dehydration influences the efficacy of various killing methods, this experiment investigated the effect of water deprivation (WD) on times to unconsciousness and death.2. Broiler chickens (n = 179) were water-deprived for 0, 24, 48 or 72 hours to mimic dehydration, then killed via manual cervical dislocation, mechanical cervical dislocation (Koechner Euthanising Device (KED)), or non-penetrating captive bolt (Zephyr-EXL), at 8, 22, 36 or 50 d of age. Degree of WD was confirmed by skin turgor, packed cell volume and body weight loss. Method efficacy was evaluated by the time to unconsciousness and death using pupillary light (PUP), palpebral blink (PAL) and nictitating membrane (NIC) reflexes, feather erection (FE), cloacal winking (CW) and convulsions (CN). The extent of damage caused by each method was examined via radiography, gross pathology and histopathology. The main effects of WD time and euthanasia method were analysed by two-way analyses of variance (CRD, PROC MIXED, SAS 9.4) with a-priori contrasts to compare water-deprived versus non-water-deprived (NON) birds.3. Skin turgor, packed cell volume and body weight loss had a quadratic relationship with WD, with highest values for those birds which were water-deprived for 72 h. WD level did not affect time to unconsciousness. Time to death was longer for WD birds than NON, with longer latencies to FE, CW and CN for water-deprived birds. WD only affected radiography or gross pathology scores on d 8, with the extent of subcutaneous haemorrhage within the neck decreasing as WD increased.4. The shortest latency to PUP loss, at all ages, and to PAL and NIC loss, at 22 d, was with the Zephyr-EXL. KED had the longest time to unconsciousness (PUP, PAL and NIC), at all ages, and to death, at 36 and 50 d.5. Overall, WD increased time to death, but did not affect the onset of unconsciousness, with no interaction between methods and WD level.

The effect of dietary alterations during rearing on feather condition in broiler breeder females.

In commercial production, broiler breeders are severely feed restricted to maintain healthy BW. This restriction can induce stereotypic behavior, including feather pecking, which has negative welfare implications for both the victim and performer. It has been suggested that the problem may be symptomatic of chronic hunger or the frustration of feeding motivation. In this study, we determined whether feather condition, as an indirect measure of feather pecking, could be improved via dietary manipulation. Six dietary treatments were tested, each with 5 replicate pens of 9 to 12 birds. Control diets (C) were fed on a daily or skip-a-day (SAD) basis. Alternative diets included soybean hulls as a bulking ingredient and calcium propionate (CaP) as an appetite suppressant of either a feed grade (F) or purified (P) quality. Both alternative diets were fed on either a daily or SAD basis. Five or 6 birds were randomly chosen from each pen and feather scored at 10, 14, 20, 26, and 36 wk of age. Six body parts (neck, back, wings, legs, vent area, tail) were given a score from 0 to 5 (0 = no feather damage, and 5 ≥ 50% feather loss with tissue damage). Scores were summed for each bird and averaged for each pen. Data were analyzed with room and feeding frequency as main factors and diet as the subfactor with repeated measures. There was an interaction between diet and time (P < 0.01) with the feather condition of the C birds worsening more quickly in comparison with the F and P birds. There was an interaction between feeding frequency and time (P = 0.015), with SAD-fed birds scoring better than daily-fed birds at 20, 26, and 36 wk. This interaction could indicate that SAD feeding increased satiety after the birds became accustomed to the schedule. Because feather condition was better with the alternative diets, this may indicate a reduction in stereotyped feather pecking with these diets. This suggests that the alternative diets increase satiety compared with the control diets.

The effect of dietary alterations during rearing on growth, productivity, and behavior in broiler breeder females.

Parent stocks of meat birds are severely feed restricted to avoid obesity-related health and fertility problems. This restriction often leads to chronic hunger, accompanied by stereotypic behavior. Research based in the United Kingdom has shown that using diets containing fiber and appetite suppressants may relieve some of the symptoms of hunger. However, few data are available regarding North American-sourced ingredients or nondaily feeding regimens. This study investigated the effects of 2 alternative diets, in combination with 2 feeding frequencies on growth, productivity, and behavior in broiler breeders. Six dietary treatments were tested, each with 5 replicate pens of 12 or 13 birds. Control diets consisted of a commercial crumble, fed on a daily or skip-a-day (SAD) basis. Alternative diets included soybean hulls as a fiber source, and calcium propionate as an appetite suppressant of either a feed-grade or purified quality, fed on either a daily or SAD basis. Birds were weighed weekly and egg production was recorded daily. Video cameras were used to record behavior during and following the morning feeding bout every 2 wk from 11 to 28 wk. Data were analyzed with a mixed model ANOVA, with repeated measures. Diet, feeding frequency, time, or an interaction of the 3 had significant effects on all observed behavior during rearing. These differences appeared to diminish during lay, with most stereotypic behavior no longer present. Very little object pecking and aggression was observed during and immediately following feeding bouts; however, daily-fed control birds still displayed this behavior more often, especially during rearing (P = 0.015). During feeding bouts, SAD birds feather pecked (P = 0.003) and rested more (P = 0.0002) than daily-fed birds. Control birds feather pecked most often (P = 0.033) after feeding bouts. Overall, the feed-grade diet appeared most effective at reducing hunger-related behavior, and the control diet appeared the least effective. There was little conclusive evidence to show that daily feeding was more effective at reducing hunger.

Efficacy of three different cervical dislocation methods for on-farm killing of layer chicks.

Unfit chicks with low viability are often euthanized in the layer industry. An effective euthanasia protocol is characterized by rapid, irreversible insensibility, followed by prompt death. This study was conducted to evaluate the efficacy of three cervical dislocation methods for killing layer chicks (2-3-day-old, avg BW ± SD; 44 ± 3 g, n = 40): manual cervical dislocation (CD), assisted manual cervical dislocation (ACD; the bird's ventral neck is placed on a blunt table edge and the back of the neck pressed firmly), and mechanical cervical dislocation by Koechner Euthanizing Device (KED-model-S). All three killing methods were assessed on anesthetized chicks (intramuscular injections of medetomidine [0.3 mg/kg BW] and ketamine [30 mg/kg BW] were used to induce clinical anesthesia). CD and ACD were also evaluated using conscious chicks to compare the killing methods and to determine the effect of anesthesia on response variables. There were no differences in time to loss of pupillary light reflex, cessation of heartbeat, or duration of gasping between conscious chicks killed with CD and ACD, but these values were all longer for conscious compared to anesthetized chicks. KED resulted in longer latencies to loss of pupillary light reflex, cessation of heartbeat, and duration of gasping. Radiographs revealed that both CD and ACD resulted in cervical luxation, mainly below the C4 vertebra, whereas KED did not cause luxation in any of the 8 chicks tested. Chicks killed by CD and ACD presented more subdural hemorrhage (SDH) at the site of cervical dislocation than those killed by KED. None of the killing methods resulted in brain trauma. Compared to CD and ACD, KED resulted in longer latency to brain death and less anatomical pathology indicating a lower efficacy of KED as an on-farm killing method.

The effect of alternative feeding strategies on the feeding motivation of broiler breeder pullets.

Due to genetic selection for fast growth and high breast meat yield, commercial strains of broiler chickens and broiler breeders are predisposed to high feed intake; however, feeding broiler breeders ad libitum impairs their health and reproductive performance. Broiler breeders are feed-restricted throughout rearing to maintain health and performance, yet feed restriction results in hunger, feeding frustration and lack of satiety. The objective of this study was to examine the effect of alternative feeding strategies, including feed additives (separately or combined) and a fixed non-daily feeding schedule, on the feeding motivation and welfare of broiler breeders during rearing. At 3 weeks of age, 180 Ross 308 breeder pullets were allocated to 90 cages and fed with one of five isocaloric treatments: (1) daily control diet (control), (2) daily calcium propionate diet (CaP), (3) daily soybean hull diet (SBH), (4) daily alternative diet (alternative: CaP + SBH) and (5) 4/3 control diet (four on-feed days and three non-consecutive off-feed days per week). The CaP diet included calcium propionate at 1.4% from 3 to 6 weeks of age, and at 3.2% from 7 to 12 weeks of age, and the SBH diet contained soybean hulls included at 40%. The alternative diet included both soybean hulls and calcium propionate at the same inclusion rate as the SBH and CaP diets, respectively. Pullets were weighed and scored for feather coverage every week. A feed intake test was conducted at 3, 4, 8, 10 and 11 weeks of age for 10 min during on- and off-feed days. At 12 weeks of age, feather samples were analysed for fault bars. Data were analysed using linear mixed regression models, with cage nested in the models and age as a repeated measure. At 4 weeks of age, pullets fed soybean hull-enriched diets (SBH and alternative diets) and those on the 4/3 schedule had lower feed intake than control pullets (P = 0.02). Feathers from pullets fed the SBH diet had fewer fault bars than those fed the CaP diet (P = 0.04). The results indicated that the inclusion of soybean hulls (alone or combined with calcium propionate) and a 4/3 feeding schedule can reduce feeding motivation of broiler breeders during early rearing.

Defining characteristics of immersion carbon dioxide gas for successful euthanasia of neonatal and young broilers.

This study investigated how the carbon dioxide (CO2) concentration within a chamber affects the efficacy of CO2 euthanasia and how the efficacy of CO2 induction methods changes as birds age. In experiment 1, pairs of broiler chicks (n = 192; 0, 3, and 6 D of age) were immersed into a chamber prefilled with 70, 80, 90, or 100% CO2. For experiment 2, 3- and 6-day-old broiler chicks (n = 88) were immersed in pairs into 100% CO2 or exposed to CO2 gradual fill in a chamber with a displacement rate of 28% chamber volume per minute. Latency to performance of headshaking (HS) and gasping (GS) as potential indicators of distress, loss of posture indicative of insensibility, and the cessation of rhythmic breathing (CRB) and cessation of movement (COM) as the indicators of death were monitored (live focal sampling/video recordings). The duration and frequency of HS and GS were assessed. For both experiments, behavior data were analyzed for CO2 method and age (4 × 3 factorial). Age and CO2 concentration interacted for latency to CRB and COM, with longer latencies for 0-day-old chicks immersed into 70% CO2 than other concentrations and ages. CO2 concentration did not affect latency to HS, GS, or loss of posture but affected CRB and COM, with latencies longest for 70% and shortest for 90 and 100% CO2. Newly hatched chicks had a longer latency to CRB and COM and longer duration and frequency of distress behaviors than older chicks. At all ages, initiation of all behaviors occurred later with gradual fill compared to immersion. There was an increased duration and frequency of distress behaviors with gradual induction compared with immersion. Overall, immersion into 90 to 100% CO2 resulted in the shortest time to insensibility and death, with a decreased duration and frequency of distress behaviors. Chicks immersed into 70% CO2 had the longest duration of GS and time to death. Age affects the efficacy of CO2 euthanasia, with increasing age decreasing time to death and the duration and frequency of distress behaviors.

The effect of alternative feeding strategies for broiler breeder pullets: 2. Welfare and performance during lay.

Feeding broiler breeders to satiety has negative consequences on their health and reproduction. Alternative feeding strategies during rearing can improve welfare, although their implications during lay are not well understood. The objective was to examine the effect of rearing feeding treatments on the reproductive performance and feeding behavior of broiler breeders under simulated commercial conditions. At 3 wk of age, 1,680 Ross 308 pullets were allocated to 24 pens under 1 of 4 isocaloric treatments: 1) daily control diet; 2) daily alternative diet (40% soybean hulls and 1 to 5% calcium propionate); 3) 4/3 control diet (4 on-feed days, 3 non-consecutive off-feed days per week); and 4) graduated control diet. Feeding frequency of the graduated treatment varied with age and finished on a daily basis. At 23 wk of age, group sizes were adjusted to 40 hens, and 5 mature Yield Plus Males roosters were introduced to each pen. Pens were under the same daily feeding management and same diet during lay. The performance of broiler breeders (growth rate, body weight uniformity, and reproductive performance) was determined until 64 wk of age. At the end of lay, feeding motivation was examined with a feed intake test and a compensatory feeding test. Data were analyzed using linear mixed regression models, with pen nested in the models and age as a repeated measure. The laying rate of hens reared on the graduated treatment decreased slower compared to control hens, resulting in a higher cumulative egg production (178.2 ± 3.8 eggs/hen) than control hens (165.2 ± 3.8 eggs/hen, P < 0.01) by 64 wk of age. Hens reared on non-daily feeding treatments laid lighter eggs with relatively heavier yolks and had higher feed intake at the end of lay than hens fed daily during rearing (P = 0.02). In conclusion, rearing feeding treatments impacted the growth rate and body weight uniformity during lay, feeding motivation at the end of lay, and the laying rate and hatchability depending on hens' age.

Evaluation of carbon dioxide induction methods for the euthanasia of day-old cull broiler chicks.

This study was conducted to evaluate the efficacy of 5 different CO2 euthanasia induction techniques for day-old cull chicks in minimizing distress and inducing a rapid loss of sensibility and death. Each induction treatment was characterized for concentration change over time, maximum concentration, and time to reach maximum. Sixteen chicks were euthanized with the gradual treatments to establish validity of treatment. Then, all 5 treatments were evaluated for effect on distress, insensibility, and death. Day-of-hatch cull chicks (n = 110) were euthanized in pairs by either immersion into 100% CO2 or gradual induction to 100% CO2 at displacement rates of 7, 14, 21, or 28% of chamber volume added per min (% vol/min). CO2 concentration was measured at chick level. Live focal observations and video recordings were used to assess latency to behavioral responses: head shaking (HS) and gasping (GS) as indicators of distress; loss of posture (LOP) as an indicator of insensibility; and cessation of rhythmic breathing (CRB) and movement (COM), indicating death. All behaviors occurred at the earliest with immersion compared to gradual treatments, and time between first signs of distress and LOP was shorter for immersion than gradual treatments. Gradual treatments showed a linear decrease in latency to HS, GS, and LOP as displacement rate increased. Latency to CRB decreased quadratically with increasing displacement rate, while COM decreased linearly. Within gradual treatments, HS and GS occurred at CO2 concentrations between 0.43 and 1.14%, LOP between 11.1 and 17.5%, while CRB and COM occurred between 61.8 and 78.4%. Overall, immersion induced distress, insensibility, and death significantly faster and with the shortest interval between distress and insensibility. For gradual treatment, insensibility and death occurred faster with increasing displacement rates. Behavioral signs of distress were observed with all treatments, and occurred at concentrations lower than those causing insensibility. In conclusion, immersion into 100% CO2 environment resulted in the shortest time of distress and fastest time to death compared to gradual displacement rates of any speed measured.

Utilization of soy hulls, oat hulls, and flax meal fiber in adult broiler breeder hens.

A total of 72, 65-week-old broiler breeder hens (Ross 308, BW 4,190 ± 45 g) was placed in individual cages to investigate utilization of fiber in soy hulls (SH), oat hulls (OH), and flax meal (FM). Birds were adapted to cages for 10 d prior to allocation (n = 18) to broiler breeder ration (control) or control mixed with either of the 3 fiber sources (wt/wt) added to supply equal amounts of neutral detergent fiber (NDF) ∼21% and TiO2. The daily feed allocation was based on 4% BW. Feed intake (FI) was monitored daily, and grab excreta samples were taken on d 16 and 17. On d 18, all birds were weighed and killed 2 h post feeding to measure ceca digesta pH and short chain fatty acids (SCFA). Relative to the control birds, birds receiving fiber lost (P < 0.05) BW due to decreased (P < 0.05) FI. The BW changes were respectively +80, -174, -133, and -585 g/bird for control, SH, OH, and FM, and corresponding FI was 1,062, 918, 885, and 590 g/bird. Birds fed FM retained higher (P < 0.05) NDF than birds fed either SH or OH. The ceca digesta pH was lower (P < 0.05) in birds receiving added fiber relative to control. However, ceca digesta pH of FM fed birds was lower (P < 0.05) than in birds fed either SH or OH, which were in turn similar (P > 0.05). Birds fed FM had higher (P < 0.05) concentration of butyric acid than birds fed the control diets, while birds fed SH and OH had intermediate butyric acid concentration. Acetic acid and total SCFA concentrations were higher (P < 0.05) in birds fed OH diet than in birds fed control but was similar (P > 0.05) to that in birds fed either SH or FM. In conclusion, short term feeding of fibrous feed ingredients reduced BW linked to reduced FI. Fiber sources exhibited differences in utilization reflective of chemical characteristics.

Opportunities for exercise during pullet rearing, Part I: Effect on the musculoskeletal characteristics of pullets.

Increased load-bearing exercise improves bone quality characteristics in a variety of species, including laying hens. Providing increased opportunities for exercise during the pullet rearing phase, a period of substantial musculoskeletal growth, offers a proactive approach to reducing osteoporosis by improving bone composition. The main objective of this study was to determine whether differing opportunities for exercise during rearing influences pullet musculoskeletal characteristics. Two flock replicates of 588 Lohmann Selected Leghorn-Lite pullets were reared in either standard, conventional cages (Conv) or an aviary rearing system (Avi) from day-old chicks until 16 wk of age. The keel bone and the muscles and long bones of the wings and legs were collected at 16 wk to measure muscle growth differences between rearing treatments and quantify bone quality characteristics using quantitative computed tomography (QCT) and bone breaking strength (BBS) assessment. Keel bone characteristics and muscle weights were adjusted for BW and analyses for QCT and BBS included BW as a covariate. At 16 wk of age, rearing system had an effect on the majority of keel bone characteristics (P < 0.05). The length of the keel metasternum, caudal tip cartilage length, and the overall percentage of cartilage present on the keel at 16 wk was greater in the Avi pullets compared to the Conv pullets (P < 0.01). Wing and breast muscle weights of the Avi pullets were greater than the Conv pullets (P < 0.001), but leg muscle weights were greater in the Conv pullets (P = 0.026). Avi pullets had greater total bone density, total cross-sectional area, cortical cross-sectional area, total bone mineral content, and cortical bone mineral content than Conv pullets for the radius, humerus, and tibia (P < 0.001). Avi pullets had greater BBS compared to the Conv pullets for the radius, humerus, and tibia (P < 0.01). Increased opportunities for exercise offered by the aviary rearing system increased muscle and bone growth characteristics in pullets at 16 wk of age.

Rearing system affects prevalence of keel-bone damage in laying hens: a longitudinal study of four consecutive flocks.

High flock-level prevalence of keel-bone fractures and deviations in laying hens are commonly reported across various housing systems; however, few longitudinal studies exist, especially for furnished and conventional cage systems. Load-bearing exercise improves bone strength and mineral composition in laying hens and has the potential to reduce keel-bone damage, especially if exercise is allowed during critical periods of bone growth throughout the pullet rearing phase. The objective of this study was to determine the prevalence of keel-bone damage in laying hens housed in furnished and conventional cages, and assess whether opportunities for exercise during the pullet rearing phase influenced the prevalence of keel-bone damage throughout the laying period. Four flock replicates of 588 Lohmann Selected Leghorn-Lite pullets/flock were reared in either conventional cages (Conv) or an aviary rearing system (Avi) and placed into conventional cages (CC), 30-bird furnished cages (FC-S) or 60-bird furnished cages (FC-L) for adult housing. Keel-bone status was determined by palpation at 30, 50, and 70 wk of age. Age (P < 0.001) and rearing system (P < 0.001) had an effect on the presence of keel-bone fractures. The presence of fractures increased with age, and hens raised in the Avi system had a lower percentage of fractures (41.6% ± 2.8 SE) compared to hens reared in the Conv system (60.3% ± 2.9 SE). Adult housing system did not have an effect on the percentage of keel fractures (P = 0.223). Age had an effect on the presence of deviations (P < 0.001), with deviations increasing with age. Rearing system (P = 0.218) and adult housing system (P = 0.539) did not affect the presence of deviations. Keel fractures and deviations were strongly associated with each other at all ages: 30 wk: (P < 0.001); 50 wk: (P < 0.001); and 70 wk: (P < 0.001). Increased opportunities for exercise provided by an aviary rearing system reduced the prevalence of keel-bone fractures through the end-of-lay.

Opportunities for exercise during pullet rearing, Part II: Long-term effects on bone characteristics of adult laying hens at the end-of-lay.

Osteoporosis in laying hens has been a production and welfare concern for several decades. The objective of this study was to determine whether differing opportunities for exercise during pullet rearing influences long-term bone quality characteristics in end-of-lay hens. A secondary objective was to assess whether differing opportunities for exercise in adult housing systems alters bone quality characteristics in end-of-lay hens. Four flock replicates of 588 Lohmann Selected Leghorn-Lite pullets were reared in either conventional cages (Conv) or an aviary rearing system (Avi) and placed into conventional cages (CC), 30-bird furnished cages (FC-S), or 60-bird furnished cages (FC-L) for adult housing. Wing and leg bones were collected at the end-of-lay to quantify bone composition and strength using quantitative computed tomography and bone breaking strength (BBS). At the end-of-lay, Avi hens had greater total and cortical cross-sectional area (P < 0.05) for the radius and tibia, greater total bone mineral content of the radius (P < 0.001), and greater tibial cortical bone mineral content (P = 0.029) than the Conv hens; however, total bone mineral density of the radius (P < 0.001) and cortical bone mineral density of the radius and tibia (P < 0.001) were greater in the Conv hens. Hens in the FC-L had greater total bone mineral density for the radius and tibia (P < 0.05) and greater trabecular bone mineral density for the radius (P = 0.027), compared to hens in the FC-S and CC. Total bone mineral content of the tibia (P = 0.030) and cortical bone mineral content of the radius (P = 0.030) and tibia (P = 0.013) were greater in the FC-L compared to the CC. The humerus of Conv hens had greater BBS than the Avi hens (P < 0.001), and the tibiae of FC-L and FC-S hens had greater BBS than CC hens (P = 0.006). Increased opportunities for exercise offered by the aviary rearing system provided improved bone quality characteristics lasting through to the end-of-lay.

Effect of space allowance and cage size on laying hens housed in furnished cages, Part I: Performance and well-being.

There are few published data on the effects of housing laying hens at different densities in large furnished cages (FC; a.k.a. enriched colony cages). The objective of this study was to determine the effects of housing laying hens at 2 space allowances (SA) in 2 sizes of FC on measures of production and well-being. At 18 wk of age, 1,218 LSL-Lite hens were housed in cages furnished with a curtained nesting area, perches, and scratch mat, and stocked at either 520 cm2 (Low) or 748 cm2 (High) total floor space. This resulted in 4 group sizes: 40 vs. 28 birds in smaller FC (SFC) and 80 vs. 55 in larger FC (LFC). Data were collected from 20 to 72 wks of age. There was no effect of cage size (P = 0.21) or SA (P = 0.37) on hen day egg production, egg weight (PSize = 0.90; PSA = 0.73), or eggshell deformation (PSize = 0.14; PSA = 0.053), but feed disappearance was higher in SFC than LFC (P = 0.005). Mortality to 72 wk was not affected by cage size (P = 0.78) or SA (P = 0.55). BW (P = 0.006) and BW CV (P = 0.008) increased with age but were not affected by treatment. Feather cleanliness was poorer in FC with low SA vs. high (P < 0.0001) and small vs. large FC (P < 0.0001). Feather condition was poorer in low SA (P = 0.048) and the best in small cages with high SA (P = 0.006), but deteriorated in all treatments over time (P < 0.0001). Treatments did not affect the breaking strengths of femur, tibia, or humerus, proportions of birds suffering keel deformations, or foot health scores. Overall, the SA studied in the 2 cage sizes in this trial had few effects on production parameters. However, stocking birds at the lower space allowance resulted in some measures of poorer external condition in both sizes of FC, which indicates that the welfare of hens housed at the lower space allowance may be compromised according to some welfare assessment criteria.

Effects of season, truck type, and location within truck on gastrointestinal tract temperature of market-weight pigs during transport.

Two experiments were done to assess the effects of season, truck type, and location in the truck on the gastrointestinal tract temperature (GTT) of market-weight pigs during transport. In Exp. 1, a total of 504 sentinel pigs were selected from a total load of 3,756 pigs over 12 wk in summer or winter and transported in either a double-decked (DD) hydraulic truck or a pot-belly (PB) trailer for 2 h. In Exp. 2, a total of 330 sentinel pigs were selected from a total load of 2,145 pigs over 11 wk in summer or winter and transported in a PB trailer for 8 h. In both experiments, sentinel pigs were equipped with a temperature data logger for the real-time GTT recording from the farm to slaughter. Transport was divided into 8 periods in Exp. 1 (rest, pretravel, initial travel, prearrival 1, prearrival 2, unloading, lairage 1, and lairage 2) and in Exp. 2 (rest, pretravel 1, pretravel 2, travel, prearrival 1, prearrival 2, lairage 1, and lairage 2). A delta GTT (ΔGTT) was calculated as the difference between the measured GTT at any determined event and the GTT measured at rest. In Exp. 1, the ΔGTT of pigs was greater ( < 0.001) in summer than in winter and only during the pretravel and initial travel periods. No difference was observed in the ΔGTT between the 2 truck types ( > 0.10). In summer, pigs located in the front top and rear top compartments of the PB trailer presented greater ( < 0.05) ΔGTT values than those transported in the middle top and front belly compartments during initial travel. In summer, during prearrival 1 and 2, a greater ( < 0.05) loss of GTT was found in pigs located in the rear top compartment of the DD truck compared with the rear lower compartment and in the front middle compartment compared with the rear middle compartment of the PB trailer. In Exp. 2, the ΔGTT of pigs was greater ( = 0.03) in summer than in winter during pretravel 2. Pigs in the front top compartment had a greater ( < 0.05) ΔGTT compared with pigs in the middle top, lower deck, and front belly compartments during the pretravel periods. Based on the results of the 2 experiments, modifications of the PB trailer model are recommended to limit body temperature increase due to physical stress at loading and unloading, and during transport due to inconsistent ventilation rate across vehicle locations.

Fire hydrant play: injuries and their prevention.

A total of 86 children treated for injuries that occurred while playing in water from fire hydrants are described. Patients were urban (100%), minority (97%) children with few alternative means for keeping cool. Injuries occurred on extremely hot summer days (mean maximum temperature 36.3 degrees C [97.5 degrees F]). Laceration of the foot on broken glass was the most common injury and was prevented by wearing footwear (P less than .001). Motor vehicles caused all serious injuries. Sprinkler attachments on the hydrants were associated with significantly fewer motor vehicle-related injuries (P less than .001) and water pressure-related injuries (P = .02). Adults were present at more than 90% of injury scenes, but had no effect on the safety of fire hydrant play. Public policy should be directed toward increasing the availability of alternative means for keeping cool, increasing the number of hydrants equipped with sprinklers, and reducing the amount of broken glass in the streets. Public education targeting adults to remove glass from the street, insist that children wear footwear, and open only those hydrants that have sprinklers could further reduce injuries to urban children who play in water from fire hydrants.

Virulence of Rickettsia prowazeki for head lice.

Wild head lice were obtained by combing out adult and instar lice from the uncut hair of school children. Normal body lice were selected from a colony of rabbit-adapted body lice obtained from the United States Department of Agriculture and maintained in the Department of Microbiology for more than 10 yr. Thirty-nine head lice and 60 body lice were fed on a rabbit that had been injected intravenously with a 10% suspension of a yolk sac pool from eggs heavily infected with the Ankara strain of virulent R. prowazeki. Five days after infection, 33 body lice and 16 head lice had survived and were feeding on a volunteer. Between Days 5 and 9, 13 head lice were dead or moribund and all of them were positive by IF for R. prowazeki. The three surviving head lice were also positive. Tests on the 33 body lice showed that 22 were positive for R. prowazeki, including four of the five body lice that survived until Day 15. In summary, head lice can be readily infected with R. prowazeki and disseminate virulent R. prowazeki organisms in their feces. Thus, theoretically, head lice appear to be highly potential as transmitters of R. prowazeki under optimal epidemiologic circumstances.

Effect of drinker type and sound stimuli on early-weaned pig performance and behavior.

Early-weaned pigs appear to be highly motivated to engage in motor patterns associated with nursing, which is thought to lead to the development of abnormal ingestive behaviors. If performance of these behaviors is related to sucking motivation, then the normal stimuli associated with nursing should stimulate pigs to perform these abnormal behaviors, specifically belly nosing. The goal of this study was to determine whether belly nosing could be affected by sow nursing vocalizations and whether the style of the drinker device influenced early-weaned pig behavior. Over six trials, 352 Yorkshire pigs were weaned at 15 d and assigned to pens (n = 44) of eight pigs based on litter, weight, and sex. Four pens in each of two rooms were outfitted with either a water nipple drinker or a drinker bowl. Rooms either had recorded sow vocalizations broadcast at hourly intervals or no sound (control). Pig behaviors were videotaped in a sample of pens (n = 32) on d 0, 1, 2, 5, 9, 11, 13, 16, and 18 after weaning. On d 0 to 2, pigs were observed continuously for feeding and drinking behaviors. On d 5 to 18, pigs were observed by scan sampling every 5 min for time budgets. Pigs with drinker bowls had higher apparent feed intakes during the first 2 d after weaning (P = 0.024), whereas they spent less time engaged in drinking behavior (P = 0.001). This coincided with an overall lower water use (P = 0.001) than that of pigs with nipple drinkers. Pigs with bowl drinkers also spent less time belly nosing than those with access to a nipple drinker (P = 0.012). Pigs in the sow vocalization treatment tended to have a higher ADG (P = 0.075), whereas they spent less time performing feeding behavior (P = 0.064). However, there was no effect of sow nursing grunts on belly nosing. These results suggest that there is a complex relationship between feeding, drinking and sucking, and belly nosing is not controlled by the same external stimuli as sucking. Because drinker type and the motor patterns that it accommodates affect belly nosing, it may be that the internal stimuli associated with nursing, such as the actual act of sucking, play a large role in the development of abnormal oral-nasal behaviors.

The choking child--a life-threatening emergency. Evaluation of current recommendations.

Recently, there has been much controversy in the pediatric literature concerning the appropriate emergency treatment of the choking child. The current recommendations of the American Academy of Pediatrics suggest a series of back blows followed by several chest thrusts. The research literature supporting these recommendations is reviewed. In addition, the data of investigators who disagree with this approach are presented. It is concluded that, although there are inadequacies in all of the existing research, there are no contraindications to the AAP recommendations. It is suggested that our focus, as pediatricians, should be on educating the lay public in the performance of a series of routine maneuvers that may be life-saving.

The effect of birth weight and age at tail docking and ear notching on the behavioral and physiological responses of piglets.

Selection for high prolificacy has resulted in litters comprising a large number of low-birth-weight (LBW) piglets. Given their presence in over 75% of litters and increased mortality rate, it is clear that a greater understanding of LBW piglet management is required for both animal welfare and productivity. In this study, we compared the effects of tail docking and ear notching LBW and average-birth-weight (ABW) piglets at 1 or 3 d of age on suckling, behavior, passive transfer of immunoglobulins, and growth. Six piglets per litter from 20 litters (n = 120 piglets) were used in a 2 × 2 complete block design. Piglets were weighed at birth and designated as LBW (0.6 to 1.0 kg) or ABW (≥ 1.2 kg) and "processed" (tail docked and ear notched) at either 1 or 3 d of age. Vocalizations were recorded during the procedures. The acute behavioral responses were observed for 10 min after the procedure. Piglets were observed for 6 h after birth and after the procedure to determine their presence at nursing bouts. On d 5, blood samples were collected to determine concentrations of serum immunoglobulins (IgA and IgG) and IGF-I. Piglet weights were recorded at birth and on d 5, 14, and 21. During the procedures, LBW piglets produced fewer (P = 0.03) calls than ABW piglets. Piglets from either birth weight category produced a similar number (calls/s; P = 0.29) of high-frequency calls (≥ 1,000 Hz), which are indicative of pain and distress, although the average frequency (Hz) of these calls was greatest (P = 0.05) for ABW piglets processed on d 3. Immediately following the procedures, LBW piglets spent more (P = 0.005) time dog-sitting and less (P = 0.005) time lying than ABW piglets. When observed with the sow, LBW males spent more (P = 0.001) time alone and had the lowest (P = 0.007) attendance at nursing bouts compared with LBW females and all ABW piglets. Concentrations of serum IgA (P = 0.06) and IgG (P = 0.04) and plasma IGF-I (P = 0.003) were lower for LBW than ABW piglets regardless of age of processing although the magnitude of these differences was likely not of biological significance. Average-birth-weight piglets may be less reactive to the acute effects of the procedures on d 1 than on d 3. Given the decreased likelihood of a LBW piglet surviving to weaning (P = 0.001), delaying processing until 3 d of age for LBW piglets may eliminate unnecessary procedures.