The purpose of this experiment was to provide information relevant to the current debate concerning the optimisation of terminal stocking density for commercial broiler production. In a modern, controlled-environment house with 24 floor pens (each 11.4 m2), 4020 day-old broilers (Ross 308) were allocated to three terminal (42 days) stocking densities (28, 34 and 40 kg m-2) x two sexes x four replicates, according to a randomised block design. Group sizes varied from 130 to 208. Husbandry conditions were in accordance with normal commercial practice. Performance and behaviour were measured systematically during each of the six weeks of life, and additional measurements were made of leg health and litter condition. Data were analysed using ANOVA to determine the effects of stocking density, sex and age. The realised mean terminal stocking densities were 28.2, 33.5 and 38.5 kg m2. The main significant effects of stocking density treatment were a linear decline in food intake with increasing density during week six (the final week), and a reduced proportion of time spent panting deeply during weeks five and six at the lowest density. Increased (shallow and deep) panting shown by females in weeks two to five suggests that if thermal discomfort becomes a problem at higher stocking densities later in the growing period, it may do so earlier in females. There was no conclusive evidence from this study that broiler welfare is compromised any more at 40 than at 34 kg m−2. The fact that the proportion of time spent panting deeply in week six was considerably lower at 28 kg m2 than at 34 and 40 kg m−2 suggests that thermal comfort (and hence welfare) at this age may be improved at densities of less than 34 kg m−2. However, the significant effects of age, age x density, and age x sex on time spent panting deeply suggest that the age at slaughter and the sex of birds in single-sex flocks should be taken into account in future considerations of optimal maximum terminal stocking density.

Spatial restriction and low cage height can reduce the rate at which comfort activities, such as wing flaps, stretching, body shakes and tail wags, are carried out by laying hens in conventional wire cages. In this study we investigated the performance of these activities in laying hens housed in furnished cages with perches and nest boxes, similar to those required in EU legislation from 2012. We compared the behaviour of groups of eight hens at a stocking density of 762 cm2 per bird with that of pairs of hens housed at a lower stocking density of 3048 cm2 per bird at two minimum cage heights of 38 cm and 45 cm. The rates of wing/leg stretches (0.80 stretches per hen per hour), tail wagging (0.76), body shaking (0.48), wing raising (0.19) and feather raising (0.05) were low, whilst full wing flaps were not observed during the study. Hourly rates of performance of wing/leg stretches (0.45 vs 1.06) and tail wags (0.34 vs 1.25) were significantly lower in eight-bird cages than in two-bird cages. We conclude that reducing the number of hens in furnished cages increases opportunities to perform certain comfort activities, but that, even at low stocking densities, comfort activities are rarely observed.

The effects on stickling lambs of two stocking densities during transport (high stocking density: eight lambs per m2; low stocking density: four lambs per m2) and two periods of lairage before slaughter (1.5 h and 3 h) were studied. The behaviour of lambs transported for short-duration journeys at the two stocking densities was recorded. At slaughter, blood samples were obtained after a lairage period and some physiological parameters related to stress were analysed: lactate dehydrogenase (LDH), creatine kinase (CK), calcium (Ca2+), Cortisol, and packed cell volume (PCV). There was a significant effect of stocking density on lambs’ behaviour during transit. The number of lambs walking was greater at low than at high density (84 and 20 observations, respectively: P < 0.001) whilst the number standing was lower at low density (852 and 366 observations, respectively). There was a significant effect (P < 0.001) of stocking density on the plasma concentration of LDH. The length of the period of lairage significantly affected plasma concentrations of LDH (P < 0.001), CK (P < 0.05), Ca2+ (P < 0.001) and Cortisol (P < 0.05), as well as PCV (P < 0.01). The results show that stocking density affects the lambs’ behaviour during transport. After the longer lairage period, plasma Cortisol concentration is lower; meanwhile, the activity of LDH and CK is higher.

An experiment was conducted to compare the effect of two levels of house stocking density (34kg m 2 and 40kg m’2) on broiler welfare and behaviour. The trial monitored 121 900 birds housed in eight flocks under commercial conditions and used a range of behavioural and productivity measures to assess welfare.

At the higher stocking density: i) the daily mortality was greater for part of the rearing period; ii) the incidence of leg problems, contact dermatitis and carcase bruising increased; Hi) the birds’ resting behaviour was increasingly disturbed; iv) locomotion and ground pecking decreased; and v) lying and preening patterns were affected, probably due to increased disruption by other birds.

Aspects of welfare were adversely affected at the higher stocking density. Further research is required to determine how stocking density affects welfare under different commercial conditions.

The behavioural effects of mixing individuals from two different flocks were studied in prepubertal lambs of about 20kg body weight kept at either low (1 animal m−2) or high (3.3 animals m−2) stocking densities. At both densities, flock mates associated preferentially with one another over the three experimental days. The social mixing conditions decreased the total number of aggressive interactions (including head-to-head clashes, head-to-body buttings and mountings). Since animals associated preferentially with flock mates, aggressive behaviours were also preferentially directed towards individuals from the same flock. Males initiated significantly more aggressive interactions than females. The total number of aggressive interactions received was similar for males and females, but females received more mountings than males. Stocking density, therefore, had no effect on aggressive behaviour. These results are discussed as they relate to transport and it is suggested that social mixing may not be a welfare problem in prepubertal lambs.

In the expanding salmon industry, many farmers use production methods that could result in poor welfare of the fish at various points of their lifecycle. We have reviewed methods used for producing salmon for food with the aim of identifying and drawing attention to factors likely to affect farmed Atlantic salmon (Salmo salar) welfare. In addition to water conditions and high stocking density at sea, other issues are important for fish welfare. Handling and transport of salmon between fresh- and seawater phases and before slaughter can have severe negative effects and research should continue to seek improved methods. Stocking densities in fresh- or seawater have substantial effects on the welfare of salmon and a reduction in densities should be considered in order to reduce fin damage in particular. Currently used feeding systems result in starvation for some fish and fin damage for others, hence new systems should be developed. Some on-demand feeding systems improve welfare. All farmed fish should be stunned prior to slaughter, not left to die of asphyxia. Carbon dioxide and electrical stunning methods do not always stun salmon humanely. The widely used methods of percussive stunning, manual or automatic, must be precise to effectively stun large numbers of fish. Welfare outcome indicators, such as fin damage, morbidity and mortality rate, should be used in standards and laws relating to salmon welfare.

The aim of this study was to assess smallholder farmer awareness in terms of good pig management and to identify serious management issues that should be readily changeable despite resources being limited in a rural setting. Methodology was a combination of questionnaire and observational surveys performed at pig-keeping households practising either confinement or a free-range system. Households were identified using the snowball method. A total of 120 pig-keeping households were included, of which 32 practised free-range systems and 88 confined their pigs. The observational survey included management practices and welfare assessment based on one pig from each of the 120 households. The results indicated that farmers were not aware of the basic requirements of pigs regardless of the production system practised. Water was often neglected and provided less frequently among those practising free-range. Pigs kept free-range also received treatment less frequently compared to those kept confined. Pigs were generally kept in poor conditions with risk of injury and without shelter from wind, rain, cold, heat, and sun. Welfare issues exist within both production systems, but issues within the confinement system could be easily eliminated with proper management. More knowledge on basic pig husbandry is required in the region and is essential for improving production. Educating farmers on the basic requirements for water and feed, alone, could vastly improve smallholder pig production. Education on pig management should therefore be a cornerstone in any research activity involving smallholder farmers in rural areas.

The response to a one-hour road journey was observed in 145 semi-feral ponies unused to handling. Ponies were transported singly or in groups of four or eight at a typical commercial ‘high’ stocking density or at a slightly reduced ‘low’ density (range 139 to 316 kg m−2). Blood samples were obtained for plasma biochemistry post transport. Behaviour during the journey of 40.2 miles was recorded using overhead video cameras. Analysis of these revealed that levels of aggression were lower in groups of four, as were the number of slips, falls, stumbles and collisions (SFSC). Within groups of four or eight, reduced stocking density was associated with lower levels of plasma cortisol and creatine kinase, reduced aggression and fewer SFSC. Levels of aggression pre-transit (observed over one hour the day before travel) were not predictive of aggression on the lorry. Single ponies were constrained to align at right angles to the direction of transport, whereas ponies transported in groups could also align forwards or backwards and were able to re-align themselves during transport especially at reduced stocking density. Of those transported singly, younger ponies showed separation anxiety, with highly-significantly greater levels of pawing and sniffing at the ground and increased packed cell volume. Thus, transporting young, untamed ponies singly is not recommended. A suitable maximum stocking density for ponies transported in groups would be approximately 200 kg m−2. However, minimum stocking density for grouped and single untamed ponies transported by road requires future investigation. Whilst stocking density was correlated with many of the variables measured during transport, stocking rate (animals per unit floor area) was not.

Leg problems are highly prevalent in modern broiler production and provision of environmental enrichment could be a strategy to improve leg health. Different types of environmental enrichment have undergone evaluation. Our objective was to conduct a systematic review of the effect of environmental enrichment on leg health in broiler chickens. The evaluation of leg health included measures of the entire leg and foot, and behavioural, pathological and physical measures. Six types of environmental enrichment were selected for inclusion: light programme, intensity of light, stocking density, perches, straw bales and separation of resources. For each type, a systematic literature search was performed. The review included 62 studies; 56 randomised trials and six cross-sectional studies. An assessment of the methodological quality of all 56 randomised trials was performed with some reporting deficits regarding occurrence of blinding, randomisation and reliability of measures. Provision of perches and increased intensity of light only displayed limited effectiveness in improving leg health and both mainly affected contact dermatitis. In contrast, there was evidence that a lowered stocking density and a dark/light schedule could improve leg health. Few studies have been carried out on the effect of straw bales and separation of resources. The few studies done have, however, shown that both types of enrichment can be effective in improving leg health. In conclusion, identifying and providing the optimal types of enrichment for broilers will reduce leg problems and increase mobility, thereby improving the welfare of the birds.

The objective of this paper is to analyse the effects of three different stocking densities on the production, stress and fear parameters of female broilers during a 46-day production period. Chickens were randomly distributed among nine floor pens in groups of 30 broilers with different space allowances for each treatment; namely eight, 20 and 30 chicks m−2. Chicken growth rate was monitored from day eleven to 46 and indicators of stress, including haematocrit, heterophil/lymphocyte ratio and concentrations of plasma corticosterone, as well as tonic immobility, were measured on days 22 and 46. On day 46, the incidence of foot and skin lesions was assessed, and stress was induced to analyse the response of broilers to each stocking density. High stocking densities cause acute stress in broilers; the effects of low and intermediate stocking densities, however, are not so evident, particularly in relation to tonic immobility and response to acute stress.

The effects of high stocking density during the dry period on dairy cow physiology, behaviour and welfare were investigated. Holstein Friesian cows (n = 48, calving over a seven month period) were dried-off 60 ± 4 d before their expected calving date, and allocated to either high (H) or low (L) stocking density groups. Cows were housed in cubicles from dry-off to 21 d before calving and then moved to straw yards until calving. In cubicle pens, H and L cows had 0.5 vs. 1.0 feed yokes/cow and 1.0 vs. 1.5 cubicles/cow, respectively, and in straw yards, 0.3 m vs. 0.6 m linear feed-face space and 6 m2vs. 12 m2 lying space, respectively. Video observations of feeding behaviour during the 3 h after feed delivery (3 d/week) and agonistic interactions at the feed-face during peak feeding (2 d/week) were made. Daily lying proportion was measured using an accelerometer device throughout the dry period. Concentrations of faecal glucocorticoid metabolites (FGCM) at dry-off, d7 and d35 after dry-off and d21 and d7 before calving and the change in energy metabolites (glucose, NEFA, BHB) from dry-off to d7 before calving were measured. H cows were less likely to start feeding within 5 min of feed delivery and spent less time feeding compared to L cows, but they engaged in displacements more frequently and spent more time standing in the feed alley. Irrespective of the treatment groups, FGCM concentrations significantly increased from dry-off to d7 after dry-off and remained higher during the dry period. Stocking density did not affect daily lying proportion, energy metabolites during the dry period and milk yield during subsequent lactation. This study found that whilst high stocking density during the dry period increased competition at the feed-face and altered feeding behaviour, it did not affect stress responses, energy metabolism or subsequent milk yield.

Noy-Meir's simple but insightful model of grazing-system dynamics was used to draw broader inferences from empirical data generated by a 17-year field trial with beef cattle grazing a Mediterranean grassland in northern Israel. After calibration of its parameters against the field results, the model predictions were tested against an independent set of data obtained from the study site; they were within acceptable deviations from the inherently noisy field data. The calibrated model was used to analyse the effects of changes to two key grazing-management factors – stocking density and early-season grazing deferment – on biomass dynamics and forage consumption. The simulated results were used to calculate forage deficits and supplementary feed requirements for optimum herd performance during the growth (‘green’) season and throughout the year. The results revealed a critical stocking density of 0.7 Animal Units (AU)/ha, above which early-season deferment reduced the amount of supplementary feed required to maintain the optimum production of the herd. Optimum stocking is higher when the grassland is used mainly in the highly nutritious green season. Responses of the strongly seasonal Mediterranean grassland to the interaction between stocking density and early-season grazing deferment were expressed by a calibrated model, in terms that determine the efficiency of forage supplementation of the herd during the green season and throughout the year.

One challenge of intensive pig production is tail damage caused by tail biting, and farmers often decrease the prevalence of tail damage through tail docking. However, tail docking is not an optimal preventive measure against tail damage and thus, it would be preferable to replace it. The aim of the current study was to investigate the relative effect of three possible preventive measures against tail damage. The study included 112 pens with 1624 finisher pigs divided between four batches. Pens were randomly assigned to one level of each of three treatments: (1) tail-docked (n=60 pens) v. undocked (n=52 pens), (2) 150 g of straw provided per pig per day on the solid floor (n=56 pens) v. no straw provided (n=56 pens), (3) stocking density of 1.21 m2/pig (11 pig/pen; n=56 pens) v. 0.73 m2/pig (18 pigs/pen; n=56 pens). Tail damage was recorded three times per week throughout the finisher period by scoring the tail of each individual pig. A pen was recorded as a tail damage pen and no longer included in the study if at least one pig in a pen had a bleeding tail wound; thus, only the first incidence of tail damage on pen level was recorded. Data were analysed by a Cox regression for survival analysis assuming proportional hazards. Results are presented as hazards, and a higher hazard means that a pen has a higher risk of tail damage and of it happening earlier in the finisher period. Pens with undocked pigs had a 4.32-fold higher hazard of tail damage compared with pens with docked pigs (P<0.001). Pens with no straw provided had a 2.22-fold higher hazard of tail damage compared with pens with straw provided (P<0.01). No interactions was seen between the treatments, but the effect of tail docking was higher than the effect of straw provision (P<0.001). Stocking density did not have a significant effect on the hazard of tail damage (hazard rate ratios (HRR)=1.67; P=0.064). However, a combination of straw provision and lowered stocking density showed a similar hazard of tail damage as seen with only tail docking (HRR=1.58; P=0.39). In conclusion, tail docking and straw provision were preventive measures against tail damage, and tail docking reduced the risk more than straw provision. A combination of other preventive measures is necessary to reduce the risk of tail damage in undocked pigs to the same level as in docked pigs.

In all, 60 Angus×Hereford heifers were ranked by age and BW (210±2 days and 220±2 kg) on day 0, and assigned to: (a) one of three drylot pens (10×14 m pens; 10 heifers/pen) resulting in a stocking density of 14 m2/heifer (HIDENS; n=3), or (b) one of three pastures (25 ha pastures; 10 heifers/pasture), resulting in a stocking density of 25 000 m2/heifer (LOWDENS; n=3). Pastures were harvested for hay before the beginning of this experiment, and negligible forage was available for grazing to LOWDENS heifers during the experiment (days 0 to 182). All heifers received the same limited-fed diet, which averaged (dry matter basis) 4.0 kg/heifer daily of hay and 3.0 kg/heifer daily of a corn-based concentrate. Heifer shrunk BW was recorded after 16 h of feed and water withdrawal on days −3 and 183 for BW gain calculation. On day 0, heifers were fitted with a pedometer behind their right shoulder. Each week, pedometer results were recorded and blood samples were collected for puberty evaluation via plasma progesterone. Plasma samples collected on days 0, 28, 56, 84, 112, 140, 161 and 182 were also analyzed for cortisol concentrations. On days 0, 49, 98, 147 and 182, hair samples were collected from the tail switch for analysis of hair cortisol concentrations. On days 28, 102 and 175, blood samples were collected for whole blood RNA isolation and analysis of heat shock protein (HSP) 70 and HSP72 mRNA expression. Heifers from LOWDENS had more (P<0.01) steps/week compared with HIDENS. No treatment effects were detected (P=0.82) for heifer BW gain. Plasma cortisol concentrations were greater (P⩽0.05) in LOWDENS compared with HIDENS heifers on days 84, 140, 161 and 182 (treatment×day interaction; P<0.01). Hair cortisol concentrations were greater (P<0.01) in HIDENS compared with LOWDENS heifers beginning on day 98 (treatment×day interaction; P<0.01). Heifers from LOWDENS had greater (P=0.04) mean mRNA expression of HSP72, and tended (P=0.09) to have greater mean mRNA expression of HSP70 compared with HIDENS. Heifers from HIDENS experienced delayed puberty attainment and had less (P<0.01) proportion of pubertal heifers on day 182 compared with LOWDENS (treatment×day interaction; P<0.01). In summary, HIDENS altered heifer stress-related and physiological responses, and delayed puberty attainment compared with LOWDENS.

Free-range laying hen systems are increasing within Australia and research is needed to determine optimal outdoor stocking densities. Six small (n=150 hens) experimental flocks of ISA Brown laying hens were housed with access to ranges simulating one of three outdoor stocking densities with two pen replicates per density: 2000 hens/ha, 10 000 hens/ha or 20 000 hens/ha. Birds were provided daily range access from 21 to 36 weeks of age and the range usage of 50% of hens was tracked using radio-frequency identification technology. Throughout the study, basic external health assessments following a modified version of the Welfare Quality® protocol showed most birds were in visibly good condition (although keel damage was increasingly present with age) with few differences between stocking densities. Toenail length at 36 weeks of age was negatively correlated with hours spent ranging for all pens of birds (all r⩾−0.23, P⩽0.04). At 23 weeks of age, there were no differences between outdoor stocking densities in albumen corticosterone concentrations (P=0.44). At 35 weeks of age, density effects were significant (P<0.001) where the eggs from hens in the highest outdoor stocking density showed the highest albumen corticosterone concentrations, although eggs from hens in the 10 000 hens/ha density showed the lowest concentrations (P<0.017). Behavioural observations of hens both on the range and indoors showed more dust bathing and foraging (scratching followed by ground-pecking) was performed outdoors, but more resting indoors (all P<0.001). Hens from the 2000 hens/ha densities showed the least foraging on the range but the most resting outdoors, with hens from the 20 000 hens/ha densities showing the least amount of resting outdoors (all P<0.017). Proportions of dust bathing outdoors tended to differ between the stocking densities (P=0.08). For each of the health and behavioural measures there were differences between pen replicates within stocking densities. These data show outdoor stocking density has some effects on hen welfare, and it appears that consideration of both individual and group-level behaviour is necessary when developing optimal stocking density guidelines and free-range system management practices.

This study assesses the economic and environmental effects to hog finishing farms from residual taxes/standards and restrictions on manure application and stocking density. Economic effects are measured in terms of net farm income and land prices, while levels of ammonia and excess nitrogen and phosphorus proxy the environmental effects. Any environmental policy requiring the need for additional land comes at a small cost to farmers who have access to adequate neighboring land. If this is not the case, then manure application and stocking density restrictions are expensive since the producer is basically forced to either purchase land or reduce hog production levels.

The number and size of free-range laying hen (Gallus gallus domesticus) production systems are increasing within Australia in response to consumer demand for perceived improvement in hen welfare. However, variation in outdoor stocking density has generated consumer dissatisfaction leading to the development of a national information standard on free-range egg labelling by the Australian Consumer Affairs Ministers. The current Australian Model Code of Practice for Domestic Poultry states a guideline of 1500 hens/ha, but no maximum density is set. Radio-frequency identification (RFID) tracking technology was used to measure daily range usage by individual ISA Brown hens housed in six small flocks (150 hens/flock – 50% of hens tagged), each with access to one of three outdoor stocking density treatments (two replicates per treatment: 2000, 10 000, 20 000 hens/ha), from 22 to 26, 27 to 31 and 32 to 36 weeks of age. There was some variation in range usage across the sampling periods and by weeks 32 to 36 individual hens from the lowest stocking density on average used the range for longer each day (P<0.001), with fewer visits and longer maximum durations per visit (P<0.001). Individual hens within all stocking densities varied in the percentage of days they accessed the range with 2% of tagged hens in each treatment never venturing outdoors and a large proportion that accessed the range daily (2000 hens/ha: 80.5%; 10 000 hens/ha: 66.5%; 20 000 hens/ha: 71.4%). On average, 38% to 48% of hens were seen on the range simultaneously and used all available areas of all ranges. These results of experimental-sized flocks have implications for determining optimal outdoor stocking densities for commercial free-range laying hens but further research would be needed to determine the effects of increased range usage on hen welfare.

Confinement housing appears to be at the forefront of concern about farm animal welfare. Although many factors may affect the welfare of commercial laying hens housed in cage and non-cage systems, welfare issues in confinement systems often involve behavioural restrictions, while many welfare issues in more extensive systems involve health and hygiene. Hens require an absolute amount of three-dimensional space in order to be able to perform basic body movements. They may prefer to distance themselves from other birds, but their strength of motivation to do so has not been thoroughly investigated, and preferred inter-individual distances may vary with activity. The relationships between the effects of space and group size on behaviour are not well understood, particularly in large groups where birds may cluster together around resources and at different times of day. There are common risks to hen welfare posed by both cage and non-cage systems such as overcrowding. However, some welfare issues present a greater risk in one system compared to another. When considering space and social environment, the comparison of cage and non-cage systems must take into account the threats to welfare that are specific to each system. Furthermore, this review highlights the importance of the design of the housing system rather than just the housing system per se.

Dual-purpose winter wheat production is an important economic enterprise in the southern Great Plains of the United States. Because of the complex interactions involved in producing wheat grain and beef gain from a single crop, stocking density is an important decision. The objective of the research is to determine the stocking density that maximizes expected net returns from dual-purpose winter wheat production. Statistical tests rejected a conventional linear-response plateau function in favor of a linear-response stochastic plateau function. The optimal stocking density of 1.48 steers/ha (0.60 steers/acre) is 19% greater with a stochastic than with a nonstochastic plateau.

At 34 days of age, 376 crossbred rabbits of both sexes were housed in 16 open-top collective pens (1.68 m2) according to a 2×2×2 factorial arrangement with two types of pen floor (plastic v. wooden slatted), two stocking densities (12 v. 16 animals/m2) and two slaughter ages (76 v. 83 days). The rabbits were examined for growth performance, slaughter results and meat quality. The effect of gender was also examined. The percentage of rabbits with wounds due to aggression varied with stocking density (8.2% v. 26.2% for 12 v. 16 animals/m2; P⩽0.001), slaughter age (15.0% v. 22.0% at 76 v. 83 days; P⩽0.10) and gender (11.3% v. 25.8% for females v. males; P⩽0.001). Rearing rabbits on a plastic rather than a wooden slatted floor promoted slaughter weight (2795 v. 2567 g; P⩽0.001), dressing percentage (61.4% v. 60.9%; P⩽0.01), dissectible fat (2.4% v. 2.0%; P⩽0.01) and hind leg muscle-to-bone ratio (5.81 v. 5.35; P⩽0.001). Increased stocking density impaired daily growth (38.5 v. 35.9 g/day; P⩽0.05) and feed intake (140 v. 134 g/day; P⩽0.01) during the second period (55 days to slaughter) and decreased slaughter weight (2725 v. 2637 g; P⩽0.01). At the older slaughter age, the feed conversion ratio was impaired (2.98 v. 3.18; P⩽0.001); the slaughter weight (2574 g v. 2788 g; P⩽0.001), dissectible fat (2.0% v. 2.4%; P⩽0.01) and hind leg muscle-to-bone ratio (5.41 v. 5.75; P⩽0.01) increased; meat thawing losses, cooking losses and shear force decreased (P⩽0.05). The main differences between the females and males were found in the slaughter for transport losses (2.6% v. 2.2%; P⩽0.01) and longissimus lumborum proportions (13.0% v. 12.4%; P⩽0.01). In conclusion, the growth performance of pen-housed rabbits was largely determined by the type of floor and less affected by stocking density. The meat quality depended on ontogenetic factors, such as slaughter age and gender, and not on housing conditions. The differences in the percentages of wounded animals owing to experimental factors deserve further investigation from the perspective of animal welfare issues.