Michael C. Appleby

Food restriction as a cause of stereotypic behaviour in tethered gilts

The behaviour of Large White × Landrace gilts tethered in stalls was studied by scan sampling from 07.00 to 17.00 h on 3 days consecutively every 5 weeks. Results are presented on 30 gilts sampled during their first 5 weeks in the house, period 1, and on 36 gilts during the following 5-week period, period 2. Twenty individuals were common to both samples. Gilts were fed at 08.00 h with a pelleted complete diet, either on low food levels (1·25 to 2·00 kg) or on high food levels (2·2 to 4·0 kg). In both periods behaviour was strongly related to food allowance in individual gilts. Gilts on low food levels spent a greater proportion of their time in the standing position than those on high food levels (period 1, medians 0·31 and 0·12 respectively; period 2, medians 0·27 and 0·11 respectively), spent more time in repetitive behaviour (period 1, medians 0·22 and 0·04 respectively; period 2, medians 0·16 and 0·07 respectively) and spent a greater proportion of their standing time in repetitive behaviour (period 1, medians 0·46 and 0 respectively; period 2, medians 0·30 and 0 respectively). Similarly, all three measures of behaviour correlated negatively with food allowance overall, but there was some indication that food level had a threshold effect, with more activity and repetitive behaviour occurring on food levels below about 2 kg. These results suggest that if food allowances are low tether stalls are not a suitable system of housing for pregnant sows.

Performance and feeding behaviour of calves on ad libitum milk from artificial teats

Weight gain, milk intake, starter intake and number of days with diarrhoea were measured for individually housed Holstein calves offered milk twice daily by bucket at 5% of body weight per feeding (n=11) or ad libitum from a teat (n=12) from birth until 4 weeks of age. Mean weight gains during the first 2 weeks were 0.36 and 0.85 kg/day and during the next 2 weeks were 0.58 and 0.79 kg/day respectively. These differences were probably the result of higher milk consumption by teat-fed versus bucket-fed calves, which occurred in all 4 weeks. Starter consumption was negligible until 3 weeks of age for both groups, but the bucket-fed calves consumed more than teat-fed calves (0.25 versus 0.11 kg/day) during week 4. Milk drinking behaviour was studied in detail for eight teat-fed calves over 24 h. Total feeding time was 47 min. All individuals took their largest meals after new milk was provided in the morning (4.7 kg at 6.4 g/s) and after milk was added in the afternoon (3.2 kg at 5.0 g/s); 74% of total daily intake was consumed in these two meals. Calves that drank more also drank faster (r=0.78 for morning meals, 0.90 for afternoon meals). Intake rate varied little over the course of large meals, although it tended to decelerate towards the end of the meal. Calves consumed the first meal of the day in 13 min, during which they were attached to the teat for 80% of the time. These meals comprised, on average, 25 individual sucking events of 25 s duration, interspersed by gaps of 7 s. Calves occasionally butted the teat, normally during the middle of the meal, and the frequency of butting correlated positively with intake rate (r=0.80). Feeding calves ad libitum from teats allows them to determine their own intake patterns while improving performance compared to conventional bucket feeding.

Effect of perches in laying cages on welfare and production of hens

Abstract 1. ISA Brown hens were caged in groups of 4 from 20 to 72 weeks at 675 cm2/bird. A control treatment in conventional cages was compared with 4 treatments involving softwood perches. In deep cages they were located across the front, across the rear and across both; in wide, shallow cages there was one long perch across the front. For half of each treatment perches were circular in cross section, and for half they were rectangular. 2. Time spent overall in daytime perching was relatively consistent over the laying cycle, from 47% in period 1 to 41% in period 10. Perch arrangement had a major influence on perching time, which varied from 20% on the rear perch to 85% on the long perch. Predominant activities on front perches were feeding and drinking; on rear perches, preening and resting. 3. Perches were heavily used for roosting at night: the proportion varied from 60 to 72% on front or rear perches, through 72 to 78% on long perches, and 99% on two perches. 4. Physical condition was also affected ...

Finding an appropriate order for a hierarchy based on probabilistic dominance

Methods of ranking individuals in a dominance hierarchy that use transitivity of relationships may obscure irregularities. Furthermore, these methods use only a small proportion of the information available from dominance encounters. This paper presents an intuitively appealing and easily implemented alternative to existing methods for ordering dominance data, developed from the work of Batchelder et al. (1992 Journal of Mathematical Psychology36, 185-212). The procedure presented here is based on a mathematical model of paired comparisons and it involves only simple estimation procedures. We illustrate its use with data on dominance among red deer Cervus elaphus, stags. The results indicate that dominance relationships are well characterized by the scale values that the model provides, and, because the method provides predictions for all pairings of animals, dominance predictions also exist for pairs of animals that have yet to be observed. Moreover, the dominance outcomes predicted by the model using the order scale are highly correlated with actual dominance observations at all levels. Overall, the procedure described provides a solution to the problem of identifying an appropriate order for a near-linear dominance hierarchy. Copyright 1999 The Association for the Study of Animal Behaviour.

Nesting, dust bathing and perching by laying hens in cages: effects of design on behaviour and welfare.

1. Laying hens (192 ISA Brown medium hybrids) were housed from 18 to 72 weeks as groups of 4 in conventional or experimental cages. The main area of all cages provided 675 cm2/hen. All experimental cages had perches, dust baths and nest boxes, which were of three types: litter (L), artificial turf (A) or plastic rollaway (P). These facilities provided an additional 375 to 480 cm2/hen. The nest boxes and dust baths occupied either high or low positions. Behaviour, physical condition and production of the birds were regularly recorded. 2. Mortality was low (1.6% overall) and egg production very good in all treatments. The proportion of cracked and dirty eggs was slightly (but not significantly) higher in the experimental cages. In the experimental cages 90% of eggs were laid overall in the nest boxes and 3% in the dust baths. The proportion laid in the nest boxes was lower early in the laying cycle and increased with time, reaching 99% in A. 3. The facilities were heavily used. Birds spent about 25% of day time on the perches and 10-15% in or near the nest box and dust bath. At night, the majority of birds (90 to 94%) roosted on perches, but most of the remainder were on the lips of the nest box or dust bath, fouling the interiors. 4. Pre-laying behaviour was much more settled in the experimental cages (45 min spent in the eventual laying position) than in the conventional ones (20 min) and total duration varied from 68 min in A to 87 min in P. The number of nest entries varied from 3.0 (A and P) to 4.3 (L); disturbance to sitting birds was correspondingly greater in L. 5. Dust bathing in the experimental cages generally took place during the afternoon in a single bout of about 5 min duration, whereas in the conventional cages it was brief and fragmented (3 bouts of 10 s each). The dust bath was also used for foraging behaviour (pecking and scratching). The treatments with small dust baths (A and P) caused problems for the birds. 6. Feather, foot and claw damage all tended to be less in the experimental than in the conventional cages, though only in the last case was the difference significant. Keel bone depressions appeared to be associated with perches; they were present in 43% of hens in the experimental cages but only 4% in conventional cages.(ABSTRACT TRUNCATED AT 400 WORDS)

Individual perching behaviour of laying hens and its effects in cages

1. ISA Brown hens were housed, from 18 to 71 weeks of age, as groups of 4 in cages with 675 cm2/bird. There were 7 treatments: control cages and 6 treatments with perches fitted across the rear of the cage. Five treatments had 450 mm wide cages, with perches made from hardwood, textured metal, smooth plastic, softwood and padded vinyl, and one treatment had a 600 mm wide cage, with a softwood perch. There were 4 cages in each of the first 6 treatments and 6 in the last. 2. Overall, birds spent about 25% of the day time on perches. Most time (28 to 41%) was spent perching on the 600 mm softwood perches. Among 450 mm perches, most time (25 to 30%) was spent on the softwood perch and least (13 to 23%) on the plastic; the results suggested that a slightly rough surface was preferred. Individual birds varied considerably in the proportion of day time they spent perching; this variation was relatively consistent over time. 3. Overall, the proportion of birds roosting on the perches at night was 85% in period 1; declined to 76% by period 6, probably because increased body size made it almost impossible for 4 birds to perch in the 450 mm cages. Birds roosting on the floor tended always to be the same individuals. 4. Damage to the soles of the feet was less in all treatments with perches than in control cages. It was least in 600 mm wide cages and showed a negative correlation with time spent perching, both within and between treatments. Long or twisted claws, in contrast, tended to be slightly worse in treatments where there was most perching. 5. Downgraded eggs tended to be slightly more frequent in cages with perches; the greatest proportion (cracked 1.4%, dirty 3.6%) was from the 600 mm wide cages, as a result of hens laying from the perch and a build-up of manure behind it. 6. Although problems remain the findings suggest that provision of perches is important for the welfare of hens; perch space should be sufficient to allow all birds to perch simultaneously.

Demand for nest boxes in laying hens.

Domestic hens (Gallus gallus domesticus) from commercial laying strains have been selected for high egg yield and may lay over 300 eggs in their working lives. In conventional wire cages, there is little opportunity to perform either nest seeking or nest building activities, which may lead to frustration each time an egg is laid. To measure the demand for a well-defined nest-site, which may act as a consummatory stimulus for nest seeking behaviour and an appetitive stimulus for nest building behaviour, 16 hens were allowed to work to gain access to a pen containing two littered, enclosed nest boxes. The cost of access to the nest boxes was varied by changing the width of the vertical gap, which divided a home pen containing food, water and a perch from the pen containing the nest boxes (gaps of 220, 140, 125, 110 and 95 mm, compared with mean body width of 117 mm). The number of entries to the nest pen declined with narrowing gap, whilst the number of failed attempts to enter rose, but all 16 hens persevered with entering the nest pen prior to oviposition and laid in the nest boxes. Between 120 and 30 min to oviposition hens made many entries with the 220 mm gap (27.6), but this declined to no entries with 95 mm gap. Hens made few entries in the last half hour prior to ovipositoin (1.3) but there was no significant decline in entries as the gap narrowed (1.1 with 95 mm gap). The number of nest inspections and nest entries also declined with width of gap, but there was no effect on time spent in the nest boxes. Hens passed gaps of 220, and 140 mm to return to the nest pen following oviposition, but did not pass gaps of 125, 110 or 95 mm. We therefore conclude that the narrow gap width can be used to assess the demand for environmental requirements. Hens were willing to pay a high cost to gain access to a nest box prior to oviposition, so prelaying behaviour may be frustrated in hens without a well-defined, littered nest site.

The Consequences and Causes of High Social Rank in Red Deer Stags

1. In a free-ranging group of male red deer (Cervus elaphus L.) on the Isle of Rhum, Scotland, that showed a strong dominance hierarchy, the consequences and causes of high social rank were investigated. 2. The reproductive success that individuals achieved in the autumn mating season correlated directly with the rank that they held in the social group in the previous winter. A causal interpretation of this association is suggested by the following results. 3. Rank was not related to age or to antler length in mature stags, so these factors could not be confounding the association. 4. Rank was related to age in young stags, and to a measure of early physical development, suggesting that body size is important in achieving high rank. Body size may also independently affect rutting success. Similarly, experience of winning interactions may influence both social rank and reproductive success. However, body size and experience are likely themselves to have been affected by rank during development, contributing to divergence among individuals of the same age. 5. Rank rarely changes among individuals of the same age, so there will be lifetime differences in rank-related advantages gained.

The Edinburgh modified cage for laying hens.

1. Behaviour, production and welfare of ISA Brown medium hybrids were assessed in 2 trials (each from 20 to 44 weeks of age) of a novel design of cage for laying hens: the Edinburgh Modified Cage (EMC). 2. The EMC was 600 mm wide, 450 mm deep and 450 mm high at the rear; it had a softwood perch and at one side a 250 mm wide nest box (containing litter or artificial turf) with a dust bath directly above. It housed 4 birds and provided 675 cm2/bird in the main cage with an additional 281 cm2/bird in the nest box. The nest box and dust bath had automatically controlled doors which were closed at night. There were 18 EMC; in the first trial these were compared with 6 control cages with perch but without next box or dust bath. 3. Hens spent 32 to 37% of day time on the perch, 5 to 7% in the dust bath and 5 to 6% in the nest. At night 92 to 98% roosted on the perch. 4. Initially only 55 to 70% of eggs were laid in the nest box partly because some eggs were laid before dawn. Once the door was retimed to open 3h before lights-on the proportion rose to 91 to 96%. Very few eggs were laid in the dust bath. Pre-laying behaviour lasted longer in treatments with nest boxes (55 to 76min) than in control cages (48min); disturbance was slight in all treatments, but lowest in control cages. 5. Dust baths were well used, with on average 61% of hens dust bathing during a 3-h afternoon observation period compared with only 17% in control cages. Two birds could use the dust bath simultaneously. 6. It was concluded that although a number of minor design features still required attention the EMC has potential to reduce the disadvantages of conventional cages for welfare while retaining their advantages and has possible commercial application.

Nesting behaviour of hens: Effects of experience on motivation

There is some controversy as to whether animals can be deprived of resources that they have never experienced. Will domestic hens (Gallus gallus domesticus), for example, that have been housed in conventional wire cages, be as motivated to use well-defined, littered nests as hens with prior experience of nests? This was tested by varying the quality of nesting cues (trials with and without an enclosed nest box) and measuring the performance of and demand for exploratory behaviour in 16 hens with and 16 hens without prior experience of such a nest site. Each hen was tested once in a two-pen arena. The ‘home’ pen contained food, water and a perch in all trials, whereas the ‘nest’ pen had an enclosed nest box attached in only half the trials. The demand for searching behaviour was assessed by varying the width of the doorway between the two pens (widths of 160, 140, 120 and 100 mm were used, compared with a mean hen width of 122 ± 11 mm). Steps, inspections and passages between the two pens were recorded in the 3 hours prior to oviposition. All hens with the nest box laid in it, and all hens without the nest box scraped out a hollow in a corner of the arena and laid there. All hens entered the nest pen prior to oviposition and there were fewer visits with narrower gaps (38 ± 6, 22 ± 9, 12 ± 3 and 4 ± 1 visits with gaps of 160 mm, 140 mm, 120 mm and 100 mm, respectively, for hens with the nest; 133 ± 32, 107 ± 17, 73 ± 20 and 49 ± 15 for hens with no nest box; p < 0.01 for both), but no other effect on searching or nesting activities. Hens with the nest box performed less exploratory behaviour (71 ± 5 inspections and 159 ± 21 steps) and made fewer passages (20 ± 5 visits) than hens without the nest box (188 ± 18 inspections, 349 ± 44 steps and 74 ± 9 visits; all p < 0.001). There was no difference in exploratory or nesting behaviour between nest-naive and nest-experienced hens, and no difference in their response to gap width. It may therefore be possible to assess deprivation by quantifying the motivation to persevere with appetitive activities in the absence of consummatory stimuli. In this experiment demand for, and expression of, nest-seeking behaviour were independent of prior experience of nesting cues and the enclosed nest box acted as a consummatory stimulus for nest-seeking behaviour.