Large Pen Research Articles

Inter-individual distances and orientation in laying hens housed in groups of three in two different-sized enclosures

Groups of 3 hens were placed in pens of two different sizes (0.65×0.65 and 1.3×1.3 m) and the locations of individuals were determined using overhead time-lapse photography. The birds did not use the areas evenly. Hens in the small pen tended to use the corners, whereas the centre of the large pen was more popular. When the observed inter-individual distances were compared with those expected to occur by chance, the birds in the small pen were found to be further apart, whereas those in the large pen were closer together than anticipated. Evidence of a strong social component influencing inter-individual distance was supported by an investigation of the relative orientation of pairs of hens. In the large pen, birds tended to orientate away from each other at distances >0.35 m and towards each other at distances less than this, whereas in the small pen this change in orientation occurred at 0.25 m.

Incidence of oestrus and oestrous trends in lactating sows housed in different social and physical environments

A range in complexity of social and physical environments comprising conventional farrowing crates, larger pens with optional outside yards or enriched environment family pens, was used for lactating sows. Additional treatments (locomotive and manipulative possibilities, social contact, restricted piglet contact) were applied to some sows. To quantify oestrous tendencies, various physiological parameters were measured and a back pressure test attempted daily from about Day 10 post-partum until weaning. No sows on farrowing crate or pen treatments exhibited lactational oestrus, but the five sows housed in family pens came on heat and were successfully mated between Days 28 and 31 of lactation. For weaned sows, the weaning-to-remating interval was 5.9±0.33 days, with no significant differences between housing types or additional treatments. There were no significant differences between treatments in the occurrence or timing of peaks in the various oestrus measures. An index combining vulval colour and size seemed to be the best single predictor of oestrus. The incidence of peaks in this index tended to occur from Day 26 post-partum onwards and this generally occurred later as the degree of restraint of sows increased.

Farrowing site preference by sows

At farrowing time, sows are normally confined in barren environments which prevent the performance of normal behaviour patterns. It has been argued that both the sows welfare and productivity may suffer as a result of these conditions, (Vestergaard and Hansen, 1984). Investigations into the feasibility of an alternative system in which the sows are not restricted have therefore been initiated. The main objective of the present study was to establish design criteria for voluntary accessed farrowing pens which will attract sows by providing them with their preferred environmental requirements.Previous observations, not reported here, were made of the pre-farrowing behaviour of sows housed individually in large pens which contained a deep sand floor and a straw dispenser. All the sows showed nest building behaviour which culminated in the production of a recognisable nest. Typically they had the following characteristics: a shallow depression; a straw lining and a nest rim which formed a low barrier around the nest. The experiments described here were designed to establish the preferences of the peri-parturient sow for preformed lying areas which incorporated these features.

Epidemiological Studies of Piglet Diarrhoea in Intensively Managed Danish Sow Herds

The study comprised 70,796 litters in 104 sow herds, observed from 1976 through 1982. Weaning age decreased from approx. 42 days to approx. 30 days during the observation period. Diseases and symptoms were recorded together with production parameters (feeding, barn construction, economic returns etc.). The mean incidence rate of pre-weaning diarrhoea was 6.8% of litters, with considerable inter-herd differences (incidence rates from 0 to approx. 50%). There was a slight increase in incidence during the autumn (August through October). Incidence rates increased with litter size, with a peak incidence in litters of 11-13 piglets, and decreased with increasing parity of the sow. There was a positive association between occurrence of arthritis and pre-weaning diarrhoea in the litters, and litters from sows with post parturient disease (MMA complex) had 1.8 times higher risk of getting diarrhoea than litters from healthy sows. No important differences among breeds were found. Small herds (less than 200 farrowings per year) had higher incidence rates than large herds (400-499 farrowings per year). Herds with a gilt proportion above 30% had an incidence rate of 12.3%, i.e. nearly twice as high as the overall mean (6.8%). There was a trend towards a higher incidence rate in litters kept in traditional pens (i.e. large pens with solid floor and loose sows) than in intensive pens (i.e. small pens with slatted flooring and tethered sows). The overall pre-weaning mortality rate was 16.2% of pigs born, half of which was due to stillbirths (6.3%) and overlaid piglets (2.2%). In litters with pre-weaning diarrhoea, the mortality rate was 19%, compared to 13% in litters without occurrence of diarrhoea. This difference accounts for an excess loss of 0.6 piglets from birth to weaning in diarrhoeic vs. non-diarrhoeic litters. Piglets from litters with pre-weaning diarrhoea had reduced weight gain. Thus, on the average, they were 2.2 days older at 25 kg bodyweight and weighed 0.4 kg less at 30 days than piglets from non-diarrhoeic litters. Also, litters with pre-weaning diarrhoea had a significantly increased risk of post-weaning diarrhoea. The present information forms a basis for defining acceptable disease thresholds in suckling litters in intensively managed herds.

Hierarchical development, agonistic behaviours, and growth rates in captive arctic fox

Six arctic fox (Alopex lagopus) kits were captured during July 1985 near Eskimo Point, N.W.T., and housed in large outside pens at Laurentian University, Sudbury, Ontario, Canada. Growth rates indicated that the species is sexually dimorphic: adult males were 7.5% larger than females. Juvenile hierarchies were nonlinear and dominant individuals were associated with neither a particular sex nor weight class. However, after fall equinox when animals had reached adult size, hierarchies became linear, and the dominant individuals were the heaviest males. Analysis of agonistic interactions indicated that the species has a rich repertoire of visual signals, which it employs to denote status and intent. These signals, ranging along a continuum from aggression to appeasement, were employed to maintain hierarchial organization and access to limited resources such as food. The results are discussed in relation to current theories on the sociality and population dynamics of the species.

Effects of Cross-Fostering on Parental Behavior of Meadow Voles (Microtus pennsylvanicus)

A cross-fostering paradigm was used to determine effects of early social environment on subsequent parental behavior of meadow voles ( Microtus pennsylvanicus ). Meadow-vole pups were fostered to either meadow-vole parents (in-fostered young) or prairie-vole parents (M. ochrogaster ; cross-fostered young). Young reared by prairie-vole parents received more parental contact than pups fostered to meadow-vole parents. At 60 days of age, nonlittermates of the same rearing condition were paired for breeding, and interactions between pairs and their litters were recorded from below large table-like pens. Postpartum nest cohabitation by males and females was observed in four of eight cross-fostered pairs; members of all eight in-fostered pairs displayed separate nesting. Cross-fostered females spent more time in the nest and exhibited more brooding, nursing, and pup grooming than in-fostered females. Cross-fostered males often entered the natal nest and engaged in more pup contact behavior than in-fostered males. In general, nonsocial behavior was unaffected by rearing condition. These results suggest that development of parental behavior in the meadow vole is subject to influence by characteristics of the early environment.

Use of birth fluids and cervical stimulation in lamb fostering.

Jackets soaked in birth fluids (BF) and cervical stimulation (CS) were used in a 2 X 2 factorial arrangement of treatments to determine their usefulness in fostering lambs. Subjects were 39, 3-d-old to 14-d-old lambs to be adopted by 39, 2-d to 7-d postpartum ewes rearing their own single lambs. Birth fluids were collected by drying newborn lambs with cloth jackets. Jackets were frozen for storage and were later thawed and placed on experimental alien lambs. Cervical stimulation was applied by attempting to insert a hand into the cervix of the ewe for 5 min immediately before presentation of an alien lamb. Maternal behavior tests, in both the absence and presence of the ewe's own lamb, were conducted twice daily in a small pen for 2.5 d. On d 3 and 4, lambs were tested in a large pen with three to four other ewes and their lambs. Aggression toward the alien lamb was greater during the first exposure in all treatments. Avoidance and nosing behaviors toward aliens were significantly less, and alien lambs were able to suckle more, when the ewe's own lamb was also present. Lambs receiving BF suckled more and were accepted more often. Cervical stimulation, in the absence of BF, improved acceptance compared with controls. The proportion of ewes accepting alien lambs were 100, 80, 60 and 10% for BF, BF-CS, CS and control treatments, respectively. Alien lambs that were accepted had similar growth rates to weaning as the ewe's own lamb. We conclude that fostering is facilitated by use of jackets soaked in BF and by CS.

Responses of cattle to different space allowances, pen sizes and road conditions during transport

Angus x Shorthorn heifers weighing about 350 kg were used to study the responses of heart rate and behaviour to different pen sizes, space allowances and road conditions during transport. In experiment 1, 6 groups of 9 heifers were transported at contrasting space allowances (0.9 and 1.1 m2/animal) on two 135- km journeys over a predetermined route of country, highway and suburban roads. Space allowance was varied by adjusting pen size. In experiment 2,4 groups of 8 heifers were used in a 2 (space allowances [0.8 and 1.0 m2/animal])x2 (pen sizes [8 and 16 m2]) factorial experiment to determine animal responses during a 31 km journey over sealed suburban roads. Space allowance was adjusted by adding non-experimental animals from the same herd. In experiment 3,6 groups of 7 animals were used to study the response of cattle to 2 space allowances (0.89 and 1.14 mVanima1) during a journey of 424 km. Space allowance was adjusted by using non-experimental animals from the same herd. In all experiments, animals transported at the lower space allowances had 3.9-6.7% lower heart rates (P < 0.05) and l27-260% lower movement scores (P < 0.05) than did animals transported at higher space allowances. In experiment 1, road type significantly affected heart rate (P<0.05) but not movement. In experiment 2, both heart rate and movement were significantly (P<0.01) less in small pens compared with large pens (heart rate 68.8 v. 71.7 bpm; number of movements 7.1 v. 15.8). There was a significant (P<0.05) interaction between space allowance and pen size on heart rate, but not on the amount of movement. In experiment 3, the stage of the journey did not affect the difference in heart rate between space allowance treatments. It is concluded that, within the ranges of the variables examined, road transport was less demanding on cattle in small pens with a small space allowance. It is suggested that space allowances can be more readily manipulated in transport vehicles with small pens and so minimise risks to animal welfare during rapid changes in vehicle motion.

Does the Siberian chipmunk respond to the snake by identifying it?

Siberian chipmunks were presented with snakes and 4 control animals (tortoises, frogs, eels, quails) in a large outdoor pen to examine whether the snakedirected behavior of the chipmunk is a response to identifying the snake or simply an exploratory behavior toward generally strange objects. The animals were presented to chipmunks in 3 manners; tethered, anesthetized, and in perforated opaque boxes and in wire netting boxes. In “tethered” and “anesthetized”, chipmunks responded significantly more intensively to snakes than to other animals. When the animals were presented in the boxes, that is, when chipmunks could perceive only olfactory stimulus from the animals, they also showed the strongest response to snakes. The results suggest that 1) snake-directed behavior of chipmunks is not a general exploratory response toward strange objects but a response to identifying the snakes, and that 2) olfaction is an important cue for the chipmunks to identify snakes.

Use of Acoustics in Studies of Fish Reaction to Imposed Stimuli

The general distribution pattern of fish in a large pen is described through essentially simultaneous measurements of the integrated echo intensity in each of six separate cells using transducers mounted below the pen. The reaction of fish to various stimuli imposed in one of the cells is quantified by the change in frequency distribution of the echo intensity relative to the undisturbed situation. The experiment was part of a small-scale test of equipment to be used for observations of the attraction-effect of fish to oil-rig structures. The method seems to be suitable both for general fish behaviour studies, including attraction and avoidance effect, and for monitoring feeding systems in aquaculture based on fish conditioning.

Genetic studies connected with artificial propagation of cod ( Gadus morhua L.)

In connection with the artificial production of cod fry in Austevoll, Norway, genetic analyses were carried out using polymorphic proteins detectable in yolksac larvae. The eggs used for propagation were collected from natural spawning in a large pen. Yolksac larvae hatched from egg samples collected at different times during the spawning period demonstrated significant genetic heterogeneity among different groups of offspring. Several groups of yolksac larvae were released into seminatural environments and survived based on natural food available in these ponds. Genetic studies of the fry produced in one pond showed, however, that they differed genetically from the broodstock. The results emphasize the importance of propagating multiple egg samples during the maximum spawning period in the artificial propagation of cod, which aims to enhance cod stocks while maintaining the genetic characteristics of the stocks. In addition, large-scale production of fry should be based on pond systems which are similar to natural environments.

Use of Acoustics in Studies of Fish Reaction to Imposed Stimuli

Abstract The general distribution pattern of fish in a large pen is described through essentially simultaneous measurements of the integrated echo intensity in each of six separate cells using transducers mounted below the pen. The reaction of fish to various stimuli imposed in one of the cells is quantified by the change in frequency distribution of the echo intensity relative to the undisturbed situation. The experiment was part of a small-scale test of equipment to be used for observations of the attraction-effect of fish to oil-rig structures. The method seems to be suitable both for general fish behaviour studies, including attraction and avoidance effect, and for monitoring feeding systems in aquaculture based on fish conditioning.

“Social sleeping” among confined horses

Modern management systems frequently exert intense pressures on the abilities of horses to adapt their natural behaviors to confinement environments which only vaguely resemble their natural habitats. The equine veterinary profession recognizes an increasing number of equine health concerns related to stress syndromes, including the direct effects of confinement on animals (such as neonatal foals) as well as indirect effects from stress that is communicated from one animal to another. A better understanding of the stressors imposed on horses by confinement should serve to decrease the incidence of management-induced physical and emotional health problems. During the past decade an aspect of equine behavior that has been much studied is their sleeping behavior. By analogy with humans, the characteristics and effectiveness of sleep might be pivotal in the susceptibility or induction of equine stress. The characteristics of an individual horse during the sleep-wakefulness cycle have been well documented. However, little attention had been focused on the modifications of this behavior caused by the interactions among the horses confined within a group (the typical management envkonment) until recently. Common sense would suggest that crowding and even the mere presence of other large moving animals could alter the depth, duration and frequency of sleep in such environments. These changes and their consequences might be especially exaggerated in young horses, still developing herd skills and status, and for whom sleep is so important. Although the behavior of horses in realistic management situations has largely been ignored by behaviorists, there has been a preliminary attempt to determine whether social sleeping differs from sleeping alone, whether group dynamics affect the sleep cycle, and whether artificial environments impact on equine sleeping behavior. The study was performed at the University of Maryland and involved the observation of a group of weanlings within individual and group enclosures of different sizes. The horses adopted recumbent postures most frequently when they were kept in 75'x15' individual outdoor pens. Each recumbent episode averaged 16 minutes. Lateral recumbency (lying on the side, all four limbs outstretched) was always accompanied by head contact with the ground. If the head was then lifted for more than a few seconds, the animals always shifted to sternal recumbency (resting on the chest, limbs usually folded in). From that position, the animals would either return to lateral recumbency, remain-in sternal recumbency or stand up. No animal was ever observed in sternal recumbency with its head on the ground. The number of recumbent episodes was about the same when the horses were kept in 12'x12' individual indoor stalls, although the average duration of a single episode was doubled. This probably reflected the relative quiet and protected nature of the stalls compared to the outdoor pens. Recumbency was much less frequent when the animals were grouped together in a 75'x75' enclosure, and occurred only rarely when they were grouped together in a 40'x40' pen. The average durations of recumbent episodes were longer in the large group pen than in the large individual pens. While the area per animal was about the same in these two environments, grouping seemed to encourage longer periods of relaxation than did semi-isolation. Perhaps the presence of others to provide a warning if necessary fostered an increased sense of security. Other observers have suggested that herd behavior may encourage relaxation.

An Experimental Study of Weaning in the Domestic Cat

AbstractThe first part of the paper describes the process of weaning in domestic cats. The subjects were seven families of cats living under laboratory conditions-each family consisting of a mother and her two kittens, living in their own large indoor pen. Observations were carried out at regular intervals from the third week after birth until the kittens were 10 weeks old. Weaning is viewed as the period during which the rate of milk transfer from mother to offspring drops most sharply. According to this definition, weaning commenced when the kittens were four weeks old and was largely completed by the time they were seven weeks old. During the weaning period mothers made suckling progressively more difficult for their kittens by increasingly adopting body postures that blocked access to their nipples. The amount of suckling declined sharply from four weeks after birth and seldom occurred after seven weeks. Kittens were first seen to eat solid food during the fifth week, and this was associated with a large increase in the variability of their daily weight gain. Prior to the start of weaning, mothers' food intake was approximately double that of non-lactating females. Male kittens grew more rapidly than their sisters and were significantly heavier. However, there was no evidence that males suckled more than females prior to the start of weaning. In general, weaning was characterised by a gradual reduction in the ease with which kittens could suckle, rather than by any overt rejection or aggression by the mother. The absence of any obvious weaning conflict is thought to be related to the favourable housing conditions (small litter size, ad libitum food, freedom from disturbances, etc.) used in this study. The second half of the paper describes the results of an experiment in which maternal lactation was interrupted during the first week of weaning. Seven Experimental (E) mothers were injected with the lactation-blocking drug bromocriptine on days 28, 30 and 33 post partum, each injection being sufficient to interrupt lactation for about 18-24 h. In the period immediately following the injections (days 29-46), E mothers and their kittens were more active than the controls, and E mothers washed their kittens more. Later on (days 47-70), E kittens suckled more than the controls-notably in the eighth week after birth, at a time when suckling would normally be rare. E mothers appeared to be more willing to let their kittens suckle during this period, as they adopted a fully accessible posture more often, and a blocking posture less often, than controls. The overall pattern of results is interpreted in terms of an initial withdrawal from the kittens in the period immediately after lactation was interrupted, followed by a later resumption of maternal care and a postponement of the end of weaning. Perhaps as a result of this continuation of suckling, the experimental treatment had no overall effect on the kittens' growth, although the Experimental kittens did grow more slowly in the week of the injections. One tentative hypothesis is that the apparent postponement of weaning represents a compensatory response to the earlier reduction in the rate of parental investment.

The influence of experimentally manipulating a component of weaning on the development of play in domestic cats

Two previous studies found that simulating aspects of early weaning, starting 5 weeks after birth, increased the frequency of object play and, to a lesser extent, social play in kittens. The present study further investigated this finding, using the lactation-suppressing drug bromocriptine to simulate a component of early weaning (a reduction in maternal milk production). The experimental manipulation was started a week earlier in ontogeny than in the previous studies. The subjects were 14 litters of domestic kittens ( Felis catus), living with their mothers in large indoor pens. Each litter consisted of two kittens. Seven Experimental (E) mothers were injected with bromocriptine on the 28th, 30th and 33rd days after their kittens were born. Seven Control (C) mothers were injected with saline. Observations of the kittens' social play, object play and locomotor play were carried out in each 3-day period from 36 to 60 days after birth. The E kittens showed significantly higher frequencies of a social play measure (Cat Contact) than the C kittens. However, object play was not significantly affected by the manipulation, in contrast to the previous studies. The E kittens also scored higher on a measure of locomotor play and fell off a climbing frame more often than the C kittens. E mothers played less than C mothers. Absolute frequencies of Cat Contacts and Object Contacts were higher in the present study than those previously reported.

Establishment of dominance in domestic Norway rats: Effects of the degree of captivity and social experience

The effect of the level of captivity and prior social experience on the establishment of dominance was examined in 16 colonies of albino rats. Males were assigned to one of four treatment groups: aggressive experience, defeat experience, exposure to electric shock, and controls. Following treatment, colonies of four males were established for 12 days in one of three different captive setings: a large outdoor pen, an indoor pen, or laboratory group cages. Effects of treatment were minimal; however, the degree of captivity significantly affected the display of aggression and the establishment of dominance relationships. In the two pen settings, attacks were more frequent and dominance relationships were established in six of eight colonies. Attacks in the laboratory cages occurred almost exclusively during the first 2 days, and no dominance relationships were established in any of eight laboratory cage colonies.

Weather and Shade Effects on Cow Corral Activities

Visual scanning at 15-min intervals was used to monitor effects of shade forms and weather types on corral activities of cows. The method allowed one person to observe several dozen cows in a large pen, regardless of grouping pattern. Complete ration eating between 0600 and 1800h was reduced 13% during hot weather, as compared to cool weather in unshaded corrals or pens with 4-m wide solid strip shades and unprotected manger. Hot afternoon fresh-feed eating response was reduced in comparison to cool weather 14% for unshaded corrals and 46% for strip shaded corrals having unprotected mangers. Cows having the strip shade plus a separate shade over the manger or a combined completely shaded free-stall rest and feeding area had double the ad libitum eating between fresh feed offerings during cool or warm weather over animals with unprotected mangers, and the response was tripled in hot weather. The percentage of cows resting or ruminating in the standing position increased linearly as temperatures increased. The effect was most evident for unshaded cows or those with the strip shade and unprotected manger. The percentage of cows drinking water or lingering around the trough without drinking increased in hot weather for unshaded animals. The observation method is taught easily, and results are useful in extension education programs.

Ethological factors influencing the occurence of oestrus in lactating sows

Observations in Edinburgh on Large White domestic pigs kept in groups outside or in family pens have indicated that sows regularly exhibit lactational oestrus in rich social and physical environments. In the pig park enclosure oestrus occured in 20 of 25 lactations and in all 21 lactations in the enriched family pen system. To further assess the stimulatory importance of selected factors of these environments, lactating sows were housed on three treatment levels differing in environmental complexity: i) conventional farrowing crates, ii) larger pens with optional outside yards, iii) enriched family pens. On each housing level additional treatment factors were applied: locomotory or manipulative possibilities, partial or full social contact with other sows and boars, restriction of suckling or piglet contact.

Selenium-Vitamin E Deficiency in Captive Wild Ducks

Seventy-five ducklings belonging to nine species of wild ducks were kept in a large floor pen. At about 8 weeks of age, a pintail and two shovelers showed clinical signs of anorexia, diarrhea, and leg weakness before death. Gross pathologic alterations included a pale discoloration of gizzard musculature and pale streaks in the leg muscle. Microscopic alterations in gizzard smooth-muscle cells included hyalinization, mineralization of sarcoplasmic debris in necrotic smooth-muscle fibers, and macrophagic invasion and phagocytosis of sarcoplasmic debris. Similar alterations were present in sections of skeletal leg muscle. The pathological lesions were characteristic of selenium-vitamin E deficiency.

Degrees of captivity and aggressive behavior in domestic Norway rats

Six categories of aggressive behaviors were studied in groups of domestic rats observed for 3 months and in three settings of varying degrees of captivity. In the least captive situation, a large outdoor pen, aggression frequently took a wild-type form (aggressive side postures, biting attacks) and infrequently took a “playful” form (pins, aggressive grooms) relative to aggression shown by rats in the most captive situation, laboratory cages. Rats housed in an intermediate degree of captivity showed intermediate levels of both serious and playful types of aggression. Male and female intruders were attacked by residents of all three settings, most seriously in the outdoor pen. These results indicate that captivity may have a powerful effect on the form of aggression shown by domestic rats.