Comparison of social ranks based on worm-running and aggressive behaviour in young domestic fowl

Worm-running is behaviour in which a chick runs carrying a worm-like object while flock mates follow and attempt to grab the object from its beak. We hypothesised that social ranks based on worm-running frequency are stable over time and are positively correlated with social ranks based on success in aggressive interactions when older. At 8-12 days of age, we scored worm-running in 17 groups of 12 female White Leghorn chicks during three 10-min tests. Based on instantaneous scans at 5-s intervals, the bird carrying the 'worm' most often was placed in rank one and so on down the rank order. These tests were repeated at 68-70 days of age. An aggression index for each bird was calculated as the number of aggressive acts given, divided by the number given and received, during three 1-h observation periods when the birds were 68-70 days. Ranks obtained in worm-running tests were positively correlated over the two age periods (P < 0.05) but were not correlated with ranks based on the aggression index (P > 0.05). Our results indicate that worm-running ranks are not predictive of success in aggressive interactions. Instead, worm-running fits some criteria for play.

Production-related traits of layers reared in different sized flocks: the concept of problematic intermediate group sizes

Laying hens were reared from 1 d of age in four replicates each of four different group sizes: 15, 30, 60, and 120 birds. To maintain stocking density at a constant 5 birds/m2, they were housed in litter floor pens of 3, 6, 12, and 24 m2, respectively. The allocation of feeder space, drinker nipples, and perch space was also constant per bird, irrespective of group size, as was the arrangement of resources in the pens. Birds were individually weighed at 3, 7, 12, 15, and 18 wk of age, and comb length and height were measured with calipers. At 24 and 39 wk, a sample of 30 eggs from each pen was weighed to determine mean egg weight. Results show a significant effect of group size on BW, with birds in the groups of 30 and 120 being lighter than birds in groups of 15 and 60. Eggs from birds in groups of 30 were significantly smaller than those from birds in the other group sizes. Comb size was unaffected by group size. We propose that these results support the theory that the hierarchical social structure based on individual recognition in small groups breaks down in large groups as birds become less aggressive and more tolerant. The results suggest that this transition occurs at a group size of around 30 birds, and that this 'intermediate' group size presents social problems for birds which, in turn, has consequences for production. The practical implication of this research is to avoid keeping birds in flocks of this size.

Computer-aided method for calculating animal configurations during social interactions from two-dimensional coordinates of color-marked body parts

In an experiment investigating the impact of preweaning social experience on later social behavior in pigs, we were interested in the mutual spatial positions of pigs during paired social interactions. To obtain these data, we applied a different colored mark to the head and back of each of 2 pigs per group and videotaped the pigs' interactions. We used the EthoVision tracking system to provide x,y coordinates of the four colored marks every 0.2 sec. This paper describes the structure and functioning of a FoxPro program designed to clean the raw data and use it to identify the mutual body positions of the 2 animals at 0.2-sec intervals. Cleaning the data was achieved by identifying invalid data points and replacing them by interpolations. An algorithm was then applied to extract three variables from the coordinates: (1) whether the two pigs were in body contact; (2) the mutual orientation (parallel, antiparallel, or perpendicular) of the two pigs; and (3) whether the pig in the "active" position made snout contact in front of, or behind, the ear base of the other pig. Using these variables, we were able to identify five interaction types: Pig A attacks, Pig B attacks, undecided head-to-head position, "clinch" resting position, or no contact. To assess the reliability of the automatic system, a randomly chosen 5-min videotaped interaction was scored for mutual positions both visually (by 2 independent observers) and automatically. Good agreement was found between the data from the 2 observers and between each observer's data and the data from the automated system, as assessed using Cohen's kappa coefficients.

Mammalian play: training for the unexpected

In this review, we present a new conceptual framework for the study of play behavior, a hitherto puzzling array of seemingly purposeless and unrelated behavioral elements that are recognizable as play throughout the mammalian lineage. Our major new functional hypothesis is that play enables animals to develop flexible kinematic and emotional responses to unexpected events in which they experience a sudden loss of control. Specifically, we propose that play functions to increase the versatility of movements used to recover from sudden shocks such as loss of balance and falling over, and to enhance the ability of animals to cope emotionally with unexpected stressful situations. To obtain this "training for the unexpected," we suggest that animals actively seek and create unexpected situations in play through self-handicapping; that is, deliberately relaxing control over their movements or actively putting themselves into disadvantageous positions and situations. Thus, play is comprised of sequences in which the players switch rapidly between well-controlled movements similar to those used in "serious" behavior and self-handicapping movements that result in temporary loss of control. We propose that this playful switching between in-control and out-of-control elements is cognitively demanding, setting phylogenetic and ontogenetic constraints on play, and is underlain by neuroendocrinological responses that produce a complex emotional state known as "having fun." Furthermore, we propose that play is often prompted by relatively novel or unpredictable stimuli, and is thus related to, although distinct from, exploration. We present 24 predictions that arise from our new theoretical framework, examining the extent to which they are supported by the existing empirical evidence and contrasting them with the predictions of four major alternative hypotheses about play. We argue that our "training for the unexpected" hypothesis can account for some previously puzzling kinematic, structural, motivational, emotional, cognitive, social, ontogenetic, and phylogenetic aspects of play. It may also account for a diversity of individual methods for coping with unexpected misfortunes.

Subjective and objective measurements of postoperative pain in cats

OBJECTIVE

To evaluate the ability of various subjective and objective measurements to determine the presence and degree of postoperative pain in cats.

DESIGN

Randomized controlled prospective clinical study.

ANIMALS

18 healthy client-owned cats.

PROCEDURE

Cats were randomly assigned to 3 groups of 6: control, tenectomy, and onychectomy. Jugular catheters were placed the day prior to surgery. All surgeries were performed by the same surgeon, and all observations were made by the same blinded trained observer. One hour prior to surgery and at assigned intervals for 36 hours after surgery, heart rate, respiratory rate, and rectal temperature were measured. Scores were assigned for 3 interaction responses, including response to palpation, by use of simple descriptive scales, and to 2 pain assessments by use of visual analogue scales. Blood was collected to measure plasma beta-endorphin and cortisol concentrations. Butorphanol was administered to all cats before surgery and to any cat subjectively assessed to be experiencing pain after surgery.

RESULTS

Only visual analogue scale scores and response to palpation scores differed significantly between control and surgical groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Determination of the presence of pain in cats can be made on the basis of observation and interaction by a trained observer. Physiologic measurements, including plasma cortisol and beta-endorphin concentrations, did not differentiate between control cats and cats that underwent surgery.

Management of Spent Hens

When hens kept for commercial egg production reach the end of their economically viable life span, they are usually transported to a processing plant for conversion into meat products. In this article, we review methods used in Canada and the United States for the catching and removing of these "spent" hens from the layer house and the subsequent loading of them onto vehicles for transport, unloading, and slaughter at the processing plant. We outline welfare concerns associated with these procedures with emphasis on bone fractures. We discuss the move toward on-farm euthanasia in North America and the humaneness of the various techniques under investigation. We conclude with recommendations aimed at increasing bone strength and improving the equipment and handling methods used in the movement and slaughter of spent hens.

Use of visual cover by domestic fowl: a Venetian blind effect?

Cover is a structural feature of the environment that animals can use to conceal themselves from predators or conspecifics or to gain shelter from inclement weather. Cover may also form a physical barrier limiting movement. It was hypothesized that domestic fowl, Gallus gallus domesticuswould use visual cover for concealment. Use of cover was examined in two strains of domestic fowl kept indoors in four groups of 110-112 birds each. In each pen, cover was provided by four rigid vertical panels, one in each of four quadrants. Four similar quadrants were without cover. To investigate use of cover for concealment, the four cover structures varied in continuity of visual cover: (1) transparent (0% cover), (2) transparent with four equidistant vertical green stripes (33% cover), (3) transparent with eight such stripes (67% cover) and (4) solid green (100% cover). Scan samples of quadrant use were made weekly when the birds were 24-52 days of age. Both strains of domestic fowl (1) used areas with cover more than areas without cover, (2) showed increased resting and preening behaviour in areas with cover and (3) showed increased use of cover as continuity increased from 0 to 67%. These results could not be explained by thermoregulatory or physical barrier effects of the cover structures. The results are consistent with the hypothesis that a preference for concealment motivates the use of visual cover by domestic fowl, and suggest a 'Venetian blind' effect for visually discontinuous security cover.

Behavioral responses of broiler chickens to handling: effects of dietary tryptophan and two lighting regimens

In three 2 x 2 factorial experiments, effects of added dietary Trp (0 or .2%, Experiments 1 and 2; 0 or .4%, Experiment 3) and two lighting regimens [1) constant 23-h photoperiod (23H); or 2) increasing photoperiod (INC)] on behavioral responses of broilers to handling were assessed. In Week 6 of Experiment 1, and Weeks 3 and 6 of Experiments 2 and 3, 32 chickens from each treatment were picked up and held by both legs for 30 s, carried for 60 s, and induced into tonic immobility (TI). In all experiments, chickens reared under INC were more likely to flap when carried, and flapped longer, than chickens reared under 23H (P < .01). In Experiments 2 and 3, INC chickens were more likely to curl the body ventrally when handled and were more susceptible to TI induction than 23H chickens (P < .05). The duration of TI was shorter on INC than 23H in Experiment 2 (P < .05), and longer in Experiment 3 (P < .001). Dietary Trp supplementation resulted in a lower flapping duration and higher incidence of body curling in Experiment 2 (P < .05), and a shorter TI duration in Experiment 3 (P < .05). Flapping, body curling, and TI responses of chickens varied between handlers (P < .05). Vocalization and flapping rates were lower, and flapping incidence and duration of flapping and TI higher, in Week 6 than in Week 3 (P < .05). Chickens reared under INC may be at greater risk of injury during preslaughter handling than chickens reared under 23H.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of lighting pattern and dietary tryptophan supplementation on growth and mortality in broilers

The effect of lighting pattern and supplementation of the diet with Trp on growth and mortality of male broiler chickens was evaluated in three experiments using 2,392, 2,608, and 2,400 chickens, respectively. There were two lighting treatments, either a constant 23 h of continuous light/24-h period or an increasing photoperiod lighting system, i.e., 0 to 3 days, 23 h light (L):1 h dark (D); 4 to 14 days, 6L:18D; 15 to 21 days, 10L:14D; 22 to 28 days, 14L:10D; 29 to 35 days, 18L:6D; 36 to 42 days, 23L:1D. The design was a completely randomized 2 x 2 factorial, with four replicates per treatment. In the first two experiments, a starter diet with or without .2% supplemental L-Trp (feed grade) was fed from 0 to 3 wk of age and a finisher diet with or without .2% supplemental Trp was fed from 3 to 6 wk of age. In the third experiment, the level of supplemental Trp was .4% in the starter and finisher diet. Birds raised on the increasing light pattern consumed less feed during the first 3 wk, were lighter in weight at 3 wk, and had lower feed:gain ratios (P < .001) than their counterparts on constant light. By market age (6 wk) they had similar body weight but feed intake was significantly (P < .05) lower in all experiments, and feed:gain ratio was significantly lower in these birds in Experiment 3 (P < .05) than in their counterparts on constant light.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of increasing photoperiod and toe clipping on breast buttons of turkeys

Two 17-wk experiments compared the effects of an increasing photoperiod treatment (INC) versus a constant photoperiod treatment (23H), and intact toes versus clipped toes, on the breast button incidence and performance of heavy tom turkeys. Under INC, the photoperiod was increased gradually from 8 to 23 h between 4 and 16 wk. Under 23H, the photoperiod remained constant at 23 h. Use of INC versus 23H resulted in a significant reduction in breast button incidence at 17 wk in both experiments (P less than .05). Toe clipping had no effect on breast button incidence. The presence of breast buttons was positively correlated with body weight at 12 wk, and area of unfeathered skin over the keel at 17 wk. In Experiment 1, the photoperiod treatments had no significant effect on 17-wk body weight or mortality, but the INC treatment had an adverse effect on feed efficiency (P less than .05). In Experiment 2, turkeys reared under INC were heavier at 17 wk (P less than .05), with similar feed efficiencies. Mortality was significantly lower on INC than 23H up to 12 wk in Experiment 2 (P less than .05). Turkeys with intact toes were .44 kg heavier than turkeys with clipped toes at 17 wk in both experiments (P less than .05) and had similar feed efficiencies. Mortality to 4 wk was lower for turkeys with intact than clipped toes in Experiment 2 (P less than .05). Increasing photoperiod treatments have potential for improving turkey performance, survival, and carcass quality.(ABSTRACT TRUNCATED AT 250 WORDS)

Avian vitreous humor concentrations of inosine, hypoxanthine, xanthine, uric acid, uracil and uridine as influenced by age and sex: their relevance as indicators of ante-mortem hypoxia

An investigation was made to determine the effects of age and sex on postmortem concentrations (mumol/l) of inosine, hypoxanthine, xanthine, uric acid, uracil and uridine in the vitreous humor of chickens (Gallus domesticus). Five male and 5 female chickens were sampled each week from 0-10 weeks of age. Samples were collected at 0 and 24 h postmortem and analysed by HPLC. Hypoxanthine, uric acid and uridine were detected at both 0 and 24 h postmortem whereas inosine, xanthine and uracil were detected only at 24 h postmortem. Neither sex nor the sex X age interaction influenced the concentrations of the compounds investigated (P greater than 0.01). Age had a significant influence on the concentrations of all compounds at 24 h postmortem (P less than 0.0001). At 0 h postmortem, age significantly affected the levels of hypoxanthine and uridine (P less than 0.0001) but not uric acid (P = 0.014). All compounds occurred at higher concentrations at 24 than 0 h postmortem with the exception of uridine at 0 and 1 week of age. Previous studies using data confounded by age and postmortem sampling time have concluded that postmortem vitreous humor hypoxanthine concentration is a useful indicator of antemortem hypoxia. The results of this study cast doubt on that conclusion. Age and postmortem sampling time should be rigorously controlled when conducting quantitative analyses of these compounds in vitreous humor.

Postmortem time and storage temperature affect the concentrations of hypoxanthine, other purines, pyrimidines, and nucleosides in avian and porcine vitreous humor

An HPLC method was used to determine whether postmortem time and storage temperature affect the concentrations of purines, pyrimidines, and nucleosides in avian and porcine vitreous humor. Inosine, hypoxanthine, xanthine, uric acid, uracil, uridine, and thymine were identified in the vitreous humor of chickens (Gallus domesticus). Time from death to sample collection (0-192 h) influenced the concentrations of all seven compounds (p less than 0.01 to less than 0.0001). The storage temperature of chicken carcasses before sampling (6 or 20 degrees C) had a significant influence on the concentrations of inosine, hypoxanthine, xanthine, uric acid, uracil, and thymine (p less than 0.05 to less than 0.0001). The interaction of postmortem time with temperature was significant for all seven compounds (p less than 0.01), with the rate of increase in concentration over time being higher at 20 than 6 degrees C. At 0 h postmortem, the vitreous humor of pigs (Sus scrofa) contained detectable levels of hypoxanthine, uracil, and uridine. Inosine, hypoxanthine, xanthine, guanosine, guanine, uracil, and uridine were detected after storage of pig eyes for 24 h at 20 degrees C. Between 0 and 24 h postmortem, there was a 22-fold increase in hypoxanthine concentration and a 13-fold increase in uracil concentration (p less than 0.0001). It was concluded that postmortem time and temperature are factors that must be taken into consideration when making comparisons of purines, pyrimidines, and nucleosides between groups and in relating postmortem vitreous humor hypoxanthine concentrations to antemortem hypoxia.

Relationships between age, body weight, and season of the year and the incidence of sudden death syndrome in male broiler chickens

The aim of this study was to examine relationships between the incidence of sudden death syndrome (SDS) in male broiler chickens and age, body weight, and season of the year. The data used were from 23 experiments conducted from July 1982 to June 1987 involving a total of 89,988 chickens aged 1-day to a maximum of 70 days. All chickens that died during the experiments were necropsied and the incidence of SDS noted. Incidence of death from SDS as a percentage of mortality ranged from 1.31 to 9.62% among experiments. Death rate from SDS showed a significant increase with body weight. The SDS mortality rate reached a maximum when birds were between 21 and 27 days of age. Death rate from SDS increased up to about 21 days and remained between 80 and 86/100,000 chickens per day to 39 days, with a gradual decline to the end of the observation period (63 days), when it was 54/100,000 per day. Death rate from SDS may be related to the month in which the experiment started, with the highest mortality occurring in January and the lowest in July. Correlations between death rates from SDS and other causes were not significant.

Influence of light intensity on behavior and performance of broiler chickens

The influence of two light intensity treatments, 180 and 6 lx, on behavior and performance of broiler chickens was examined in two experiments. The first experiment tested male chickens reared to 9 wk of age and the second experiment tested both sexes reared separately to 6 wk. Behavioral data were collected by scan sampling of behavior recorded on video tape. Standing, walking, and total activity were higher under the 180 lx than the 6-lx treatment (P less than .01), whereas feeding and drinking were not significantly affected by light intensity. Body weight, feed and water consumption, and feed conversion were unaffected by light intensity. Incidence of leg disorders at 6 wk and the percentage of bruised carcasses at 64 days were significantly lower under the higher light intensity treatment in the first experiment, as was mortality to 3 and 6 wk in the second experiment. No significant light intensity X sex interactions were detected. Results did not support the hypothesis that brighter lighting reduces performance due to increased chicken activity. Use of brighter lighting had no adverse effects on performance and there was some evidence that it may have a beneficial effect on welfare by reducing bruising.

Effect of estradiol-17 beta-monopalmitate on the incidence of sudden death syndrome in male broiler chickens

One-thousand male broiler crossbred chickens were implanted subcutaneously with 15 mg of estradiol-17 beta-monopalmitate at 2 wk of age; another 1,000 chickens served as untreated controls. Each of the treatments consisted of 8 pens of 125 chickens each. All chickens that died during the 9-wk experiment were necropsied and the incidence of sudden death syndrome (SDS), determined. There was no significant difference between treated and control groups in total mortality or in mortality attributed to SDS. Treated birds had higher feed-to-gain ratios and drank more water than controls.

Fatty acid composition of hepatic and cardiac tissue from chickens dying of sudden death syndrome

Gas chromatographic analysis of tissue lipids from broiler chickens dying from sudden death syndrome (SDS) were carried out to determine if anomalies in fatty acid composition could be linked to the disease. Crude extracts of lipids from hearts and livers of chickens dying from SDS and their matched controls (matched for pen number, sex and time of death) were fractionated by thin layer chromatography and the phospholipid, triacylglycerol (TG) and nonesterified aliphatic carboxylic acid [C14-C22] (FA) fractions were transmethylated and analysed by capillary gas chromatography. A number of significant (P less than .05) differences in fatty acid composition were found to exist between males dying of SDS and their controls, the most notable being elevated levels of arachidonic acid in the hepatic TG and cardiac FA fractions of SDS males. Few significant differences were found between SDS females and their controls. There was a trend toward increased desaturation of cardiac and hepatic tissue lipids of male SDS chickens, although this was significant only for the hepatic TG fraction. The results did not support the hypothesis that a lack of arachidonic acid as a precursor of prostaglandin synthesis was a causative factor in the disease.

Behavior of chickens prior to death from sudden death syndrome

A study was made to determine if chickens dying from sudden death syndrome (SDS) showed any unusual behavioral characteristics during the final 12 h preceding death. Continuous video recordings were made of floor pens of 50 to 120 individually marked male broiler chickens between 3 and 10 wk of age. Behavioral data were obtained from video tapes played back following death of chickens from SDS. Analysis of the video tapes revealed no significant differences between 10 SDS chickens and their matched controls in the frequencies or proportions of time spent in each of 19 different behavioral activities. All SDS chickens exhibited a sudden attack prior to death lasting an average of 53 s and characterized by loss of balance, violent flapping, and strong muscular contractions. There was no evidence that death was preceded by a particular environmental or behavioral event. It was concluded that there were no consistent behavioral symptoms which could be used to identify SDS chickens prior to death.

Light intensity effects on performance, activity, leg disorders, and sudden death syndrome of roaster chickens

The effects of light intensity on performance, activity, leg disorders and sudden death syndrome (SDS) of male chickens were examined in two experiments. In each experiment 5,600 1-day-old chicks were divided evenly between 8 light-proof floor pens and reared to 9 weeks of age on one of four light intensity treatments: .5, 10, 20, and 30 1x in Experiment 1 and .1, 1, 10, and 100 1x in Experiment 2. Light intensities less than 10 1x were phased in gradually by 3 weeks of age. Light intensity had no effect on 3, 6, or 9-week body weight, incidence of leg disorders, total mortality, or mortality due to SDS in either experiment (P greater than .05). Effects of light intensity on feed conversion and carcass quality were inconsistent across the two experiments. In both experiments chicken activity, as measured by the proportion of birds standing up of those present in a 2.25-m2 floor grid in each pen, decreased with age (P less than .01) and was influenced by a light intensity by age interaction (P less than .05). It was concluded that bright lighting (greater than or equal to 10 1x) was not effective in reducing the incidence of leg disorders or in altering the SDS mortality rate.

Effect of alternating lights and strain on behavior and leg disorders of roaster chickens

The effects of light treatment and strain on movement, spacial distribution, activity, and incidence of leg disorders of 4 to 10-week-old male chickens were examined in two experiments. In both, an alternating light treatment, in which high-intensity light alternated from one side of the barn to the other against a background of low intensity light, was compared with a control light treatment of continuous low intensity light supplied to both sides of the barn. Two strains were tested in each experiment. In Experiment 1, chickens responded to the alternating light between 4 and 7 weeks of age, although not between 7 and 10 weeks of age, by moving into areas of relatively high intensity light. In Experiment 2, chickens responded during both periods by moving into areas of relatively low intensity light. Bird distribution was also affected by a geographical side preference. In both experiments, activity was higher in areas of high vs. low light intensity, higher under alternating than control light, and higher for younger than older birds (P less than .05). Activity was also influenced by strain (P less than .01). Incidence of leg disorders was influenced by strain (P less than .01) but not light treatment.

The Suckling Behaviour of Domestic Pigs in a Semi-Natural Environment

Abstract

The suckling behaviour of domestic pigs living in a socially and ecologically rich outdoor environment was examined in order to obtain a baseline for comparison with behaviour in more restricted and barren environments. It was found that the piglets' growth rates were not consistently influenced by their suckling location along the udder, and that the concept of dominance at the udder was not justified. Crowding at the udder was probably an important factor prompting piglets to seek milk and solid food elsewhere, and two piglets switched from suckling from their own mother to suckling from another sow. True communal suckling was not exhibited. Piglets were responsible for locating their preferred teat and defending it from others. Sows did not attempt to prevent familiar piglets from other litters from suckling from them, although they sometimes terminated a suckling bout when disturbed by fights at the udder. Synchronization of suckling between litters was common. Suckling bouts did not always result in milk let-down, indicating that this is not a phenomenon exclusive to intensive housing systems. Weaning occurred naturally between 60 and 100 days after birth, and its timing varied both within and between litters but was not closely linked to the amount of aggression received from the sow.