Space use according to the distribution of resources and level of competition

Evaluating Behavior Recognition Pipeline of Laying Hens Using Wearable Inertial Sensors

Recently, animal welfare has gained worldwide attention. The concept of animal welfare encompasses the physical and mental well-being of animals. Rearing layers in battery cages (conventional cages) may violate their instinctive behaviors and health, resulting in increased animal welfare concerns. Therefore, welfare-oriented rearing systems have been explored to improve their welfare while maintaining productivity. In this study, we explore a behavior recognition system using a wearable inertial sensor to improve the rearing system based on continuous monitoring and quantifying behaviors. Supervised machine learning recognizes a variety of 12 hen behaviors where various parameters in the processing pipeline are considered, including the classifier, sampling frequency, window length, data imbalance handling, and sensor modality. A reference configuration utilizes a multi-layer perceptron as a classifier; feature vectors are calculated from the accelerometer and angular velocity sensor in a 1.28 s window sampled at 100 Hz; the training data are unbalanced. In addition, the accompanying results would allow for a more intensive design of similar systems, estimation of the impact of specific constraints on parameters, and recognition of specific behaviors.

Environmental change or choice during early rearing improves behavioural adaptability in laying hen chicks

Laying hens are typically moved to a novel environment after rearing, requiring adaptability to cope with change. We hypothesized that the standard rearing of laying hen chicks, in non-changing environments with limited choices (a single variant of each resource), impairs their ability to learn new routines, use new equipment and exploit new resources. On the contrary, rearing in a changing environment that also offers a choice of resource variants could better prepare chicks for the unexpected. To explore this hypothesis, environmental change and choice were manipulated in a 2 × 2 factorial experiment. Compared to standard rearing, greater change during early rearing, through repeatedly swapping litter and perch types, reduced initial freezing when exposed to a novel environment suggesting a lower fear response. Greater choice during rearing, through simultaneous access to multiple litter and perch types, resulted in shorter latencies to solve a detour task, more movement in novel environments and less spatial clustering, suggesting improved spatial skills and higher exploration. However, combining both change and choice did not generally result in greater improvement relative to providing one or the other alone. We conclude that environmental change and choice during rearing have different positive but non-synergistic effects on later adaptability potential.

Pre-Partum Supplementation with Polyunsaturated Fatty Acids on Colostrum Characteristics and Lamb Immunity and Behavior after a Mild Post-Weaning Aversive Handling Period

We studied the effect of pre-natal supplementation with n-3 α-linolenic acid (ALA) combined with a tannin-rich forage on colostrum composition and immunological quality and whether these changes had advantageous effects on lambs’ survival and stress reaction to a post-weaning stressor. Forty-eight Latxa ewes were fed during the last five weeks of pregnancy with two experimental diets: a control diet based on a neutral concentrate and forage (tall fescue hay; CO-FES), and a supplemented diet based on polyunsaturated (PUFA)-rich concentrate and tanniferous forage (sainfoin; ALA-SAIN). After parturition, twenty ewes had their blood and colostrum sampled, and their lambs were monitored until post-weaning. Lambs were afterwards subjected to (i) an aversive handling period (AHP) followed by a behavioral assessment and (ii) inflammatory and lymphocyte proliferation challenge. Feeding ALA-SAIN resulted in changes in colostrum fatty acid composition, specifically higher α-linoleic acid (p < 0.001), conjugate linoleic acid (p = 0.005), vaccenic acid (p = 0.006) and long-chain n-3 PUFA (p = 0.004). Pre-partum nutrition did not affect lamb immunoglobulin (Ig) G apparent efficacy absorption, but circulating IgG tended to be higher (p = 0.054) in ALA-SAIN lambs. ALA-SAIN lambs interacted more frequently with other lambs (p = 0.002), whereas ALA-SAIN females spent more time closer to other lambs (p < 0.001). Plasma cortisol was higher (p = 0.047) and plasma interleukin (IL)-2 lower (p = 0.003) in CO-FES lambs. This research highlights the importance of prenatal nutrition on the immune system stimulation and lambs’ behavior as a strategy to improve lambs’ health and welfare during early life.

The Impact of Group Size on Welfare Indicators of Ewes during Pregnancy

Group size (GS) and space allowance have major implications for the welfare of production species, however their effects are often confounded. In a previous study we investigated the impact of varying space allowance at constant GS. In the present work we report the consequences of varying GS on pregnant ewes while controlling space allowance. We housed ewes at 6 (GS6) or 12 ewes/enclosure (GS12), while controlling space allowance to 1.5 m2/ewe (3 enclosures/treatment), and necessarily varying enclosure size. Therefore, when indicating GS effects we implicitly reflect a confounding effect with that of enclosure size. Movement, use of space, behaviour, serum cortisol concentration and body condition score (BCS) were collected during the last 12 gestation weeks. Movement, use of space, and behaviour were collected every other week, during 2 days/week, using 10 minute continuous scan samplings. Blood was collected during weeks 10, 13, 17, and 21 of gestation, and BCS during weeks 15 and 21. Data were analysed using repeated measures, generalized linear mixed models, with GS, week, and their interaction as fixed effects, and enclosure as random effect. GS mainly affected movement and use of space. GS12 ewes walked longer distances using longer steps (P<0.001). An interaction GS by week was observed for angular dispersion (P<0.0001), which was smaller for GS12 from week 10 onwards. Initial restlessness levels were lower for GS12, as shown by the reduced frequency of location changes (P<0.0001). Furthest and mean neighbour distances increased with GS (P<0.0001). The effect of GS on behaviour was only evident for eating behaviour as an interaction with gestation week (P<0.05). Changes in behaviour, movement and use of space along the study indicated an activity peak during weeks 3 to 5. Cortisol changes during gestation (P<0.01) also reflected this activity peak, while BCS (P<0.001) reflected normal physical condition changes during pregnancy. Although the separate effects of GS and enclosure size cannot be disentangled, we conclude that if enough space/ewe is given during gestation, larger GS will result in larger effective space, and no major implications for the welfare of ewes should be expected as GS increases. Ewes will adapt their movement patterns and use of space to enclosure size, and no further behavioural, physiological and physical consequences should be expected.

Effect of available space and previous contact in the social integration of Saint Croix and Suffolk ewes

Reproduction in tropical sheep is not affected by season, whereas the reproductive cycle of temperate-climate breeds such as Suffolk depends on the photoperiod. Close contact with tropical ewes during the anestrous period might induce Suffolk ewes to cycle, making the use of artificial light or hormonal treatments unnecessary. However, the integration of both breeds within the social group would be necessary to trigger this effect, and so the aim of the experiment was to determine the speed of integration of 2 groups of Saint Croix and Suffolk ewes into a single flock, according to space allowance and previous experience. For this, 6 groups of 10 ewes (half from each breed) from both breeds, housed at 2 or 4 m/ewe (3 groups/treatment) and with or without previous contact with the other breed, were monitored for 3 d. Each observation day, the behavior, movement, and use of space of ewes were collected during 10 min at 1-h intervals between 0900 and 1400 h. Generalized linear mixed models were used to test the effects of breed, space allowance, and previous experience on behavior, movement, and use of space. Net distances, interbreed farthest neighbor distance, mean interbreed distance, and walking frequencies were greater at 4 m/ewe ( < 0.05). Intrabreed nearest neighbor, mean intrabreed neighbor, and interbreed nearest neighbor distances and minimum convex polygons at 4 m/ewe were greatest for Saint Croix ewes, whereas the opposite was found for lying down ( < 0.05). Experienced ewes showed larger intrabreed nearest neighbor distances, minimum convex polygons, and home range overlapping ( < 0.05). Experienced ewes at 4 m/ewe showed longest total distances and step lengths and greatest movement activity ( < 0.05). Experienced ewes walked longer total distances during Day 1 and 2 ( < 0.05). Lying down frequency was greater for Day 3 than Day 1 ( < 0.05), and Suffolk ewes kept longer interindividual distances during Day 1 ( < 0.05). After 3 d of cohabitation, Suffolk and Saint Croix ewes did not fully integrate into a cohesive flock, with each breed displaying specific behavioral patterns. Decreasing space allowance and previous experience resulted in limited benefits for the successful group cohesion. Longer cohabitation periods might result in complete integration, although practical implementation might be difficult.

Density-Dependent Spacing Behaviour and Activity Budget in Pregnant, Domestic Goats (Capra hircus)

Very little is known about the spacing behaviour in social groups of domestic goats (Capra hircus) in the farm environment. In this experiment, we studied interindividual distances, movement patterns and activity budgets in pregnant goats housed at three different densities. Norwegian dairy goats were kept in stable social groups of six animals throughout pregnancy at 1, 2 or 3 m² per individual and their spacing behaviours (i.e. distance travelled, nearest and furthest neighbour distance) and activity budgets (e.g. resting, feeding, social activities) were monitored. Observations were made in the first, second and last thirds of pregnancy in the mornings, at noon and in the afternoons of each of these phases (4.5 hours per observation period). The findings show that goats held at animal densities of 2 and 3 m² moved longer distances when they had more space per animal and kept larger nearest and furthest neighbour distances when compared to the 1 m² per animal density. Less feeding activity was observed at the high animal density compared to the medium and low density treatments. The phase of gestation also had an impact on almost all behavioural variables. Closer to parturition, animals moved further distances and the increase in nearest and furthest neighbour distance was more pronounced at the lower animal densities. During the last period of gestation, goats spent less time feeding and more on resting, social behaviours and engaging in other various activities. Our data suggest that more space per goat is needed for goats closer to parturition than in the early gestation phase. We concluded that in goats spacing behaviour is density-dependent and changes with stages of pregnancy and activities. Finally, the lower density allowed animals to express individual preferences regarding spacing behaviour which is important in ensuring good welfare in a farming situation.

Space availability in confined sheep during pregnancy, effects in movement patterns and use of space

Space availability is essential to grant the welfare of animals. To determine the effect of space availability on movement and space use in pregnant ewes (Ovis aries), 54 individuals were studied during the last 11 weeks of gestation. Three treatments were tested (1, 2, and 3 m2/ewe; 6 ewes/group). Ewes' positions were collected for 15 minutes using continuous scan samplings two days/week. Total and net distance, net/total distance ratio, maximum and minimum step length, movement activity, angular dispersion, nearest, furthest and mean neighbour distance, peripheral location ratio, and corrected peripheral location ratio were calculated. Restriction in space availability resulted in smaller total travelled distance, net to total distance ratio, maximum step length, and angular dispersion but higher movement activity at 1 m2/ewe as compared to 2 and 3 m2/ewe (P<0.01). On the other hand, nearest and furthest neighbour distances increased from 1 to 3 m2/ewe (P<0.001). Largest total distance, maximum and minimum step length, and movement activity, as well as lowest net/total distance ratio and angular dispersion were observed during the first weeks (P<0.05) while inter-individual distances increased through gestation. Results indicate that movement patterns and space use in ewes were clearly restricted by limitations of space availability to 1 m2/ewe. This reflected in shorter, more sinuous trajectories composed of shorter steps, lower inter-individual distances and higher movement activity potentially linked with higher restlessness levels. On the contrary, differences between 2 and 3 m2/ewe, for most variables indicate that increasing space availability from 2 to 3 m2/ewe would appear to have limited benefits, reflected mostly in a further increment in the inter-individual distances among group members. No major variations in spatial requirements were detected through gestation, except for slight increments in inter-individual distances and an initial adaptation period, with ewes being restless and highly motivated to explore their new environment.

Social interaction of juvenile Japanese quail classified by their permanence in proximity to a high or low density of conspecifics

One challenge faced by ethologists in poultry welfare is helping birds to form functionally successful groups over time through the expression of appropriate behaviors. Searching for phenotypic variability, we developed in Japanese quail a density-related permanence (DRP) test that enables us to classify young birds (while in groups) according to their individual permanence in boxes containing a high or low density of confined conspecifics (HD or LD, respectively). This study addressed the question of whether contrasting DRP quail behavior may reflect underlying differences in social responses. Birds were classified at 11 d of age in an apparatus consisting of 2 boxes interconnected by a central region delimited by sliding doors. Each box contained at its distal end either 12 or 3 conspecifics confined behind a glass (high or low density, respectively). The doors were closed 9 times every 1 h, and positioning of 36 experimental birds was registered. If birds were found in the box containing high density, low density, or in the central region, they received a 1, -1, or a 0 score, respectively. Birds with final summed scores of ≥3 or ≤-3 were categorized as HD or LD, respectively. Same category groups (HD or LD) were evaluated in their home box (undisturbed) and in a resident/intruder test when 38 d old. A higher proportion of LD than HD groups (5/6 vs. 1/6, respectively) showed at least one aggressive pecking event during a 1-h trial. The LD groups also showed a higher number of aggressive pecking events than HP groups. When an unfamiliar intruder (either HD or LD) was incorporated during 5 min in the HD or LD box, LD resident quail showed shorter latencies and a higher number of aggressive pecking events toward the intruder bird than their HD counterparts. The early individual permanence in the DRP test could be considered a consequence of a different adaptability strategy for group living. This novel test could be relevant for selection programs aiming to obtain birds better suited for rearing in high-density conditions.

When continuous observations just won't do: developing accurate and efficient sampling strategies for the laying hen

Continuous observation is the most accurate way to determine animals' actual time budget and can provide a 'gold standard' representation of resource use, behavior frequency, and duration. Continuous observation is useful for capturing behaviors that are of short duration or occur infrequently. However, collecting continuous data is labor intensive and time consuming, making multiple individual or long-term data collection difficult. Six non-cage laying hens were video recorded for 15 h and behavioral data collected every 2 s were compared with data collected using scan sampling intervals of 5, 10, 15, 30, and 60 min and subsamples of 2 second observations performed for 10 min every 30 min, 15 min every 1 h, 30 min every 1.5 h, and 15 min every 2 h. Three statistical approaches were used to provide a comprehensive analysis to examine the quality of the data obtained via different sampling methods. General linear mixed models identified how the time budget from the sampling techniques differed from continuous observation. Correlation analysis identified how strongly results from the sampling techniques were associated with those from continuous observation. Regression analysis identified how well the results from the sampling techniques were associated with those from continuous observation, changes in magnitude, and whether a sampling technique had bias. Static behaviors were well represented with scan and time sampling techniques, while dynamic behaviors were best represented with time sampling techniques. Methods for identifying an appropriate sampling strategy based upon the type of behavior of interest are outlined and results for non-caged laying hens are presented.

Sex modifies genetic effects on residual variance in urinary calcium excretion in rat (Rattus norvegicus)

Conventional genetics assumes common variance among alleles or genetic groups. However, evidence from vertebrate and invertebrate models suggests that residual genotypic variance may itself be under partial genetic control. Such a phenomenon would have great significance: high-variability alleles might confound the detection of "classically" acting genes or scatter predicted evolutionary outcomes among unpredicted trajectories. Of the few works on this phenomenon, many implicate sex in some aspect of its control. We found that female genetic hypercalciuric stone-forming (GHS) rats (Rattus norvegicus) had higher coefficients of variation (CVs) for urinary calcium (CV = 0.14) than GHS males (CV = 0.06), and the reverse in normocalciuric Wistar-Kyoto rats (WKY) (CV(♂) = 0.14; CV(♀) = 0.09), suggesting sex-by-genotype interaction on residual variance. We therefore investigated the effect of sex on absolute-transformed residuals in urinary calcium in an F(2) GHS × WKY mapping cohort. Absolute residuals were associated with genotype at two microsatellites, D3Rat46 (RNO3, 33.9 Mb) and D4Mgh1 (RNO4, 84.8 MB) at Bonferroni thresholds across the entire cohort, and with the microsatellites D3Rat46, D9Mgh2 (RNO9, 84.4 Mb), and D12Rat25 (RNO12, 40.4 Mb) in females (P < 0.05) but not males. In GHS chromosome 1 congenic lines bred onto a WKY genomic background, we found that congenic males had significantly (P < 0.0001) higher CVs for urinary calcium (CV = 0.25) than females (CV = 0.15), supporting the hypothesis of the inheritance of sex-by-genotype interaction on this effect. Our findings suggest that genetic effects on residual variance are sex linked; heritable, sex-specific residuals might have great potential implications for evolution, adaptation, and genetic analysis.

The effect of reduction concentrations of the broiler chickens per unit area on the final live weight and production economics

The aim of the present study was a mathematical and statistical assessment for the effect of concentration of broiler chickens per unit area to the final live weight and production economics. Cobb 500 chickens were fattening for 42 days in a hall on deep litter. During the two experiments the chickens were divided to two groups according to concentration per unit area and it was about 30 and 25 kg/m2. The experiments had been complied with recommended  nutritional  requirements  for  breeding  and  final fattening type of chickens Cobb500. The average final weight of broiler chickens in the first experiment were 2.14 and 2.17 kg for concentrations of 29.41 and 25.76 kg/m2 respectively, and for the second experiment  were 2.01 and 2.02 kg for concentrations of 29.33 and 23.90 kg/m2 respectively. According to statistical analysis (P≥0.05), the average final live weight of broiler chickens was not affected by concentrations.  The calculated production total live weight of broiler chickens across the halls were 48526.5, 48 394.5, 42504.0 and 39435.0 kg at a concentrations of 29.41, 29.33, 25.76 and 23.90 kg/m2 respectively.  By reducing the concentration of birds in the hall from 29.41 to  29.33 kg/m2 and from 25.76 to 23.9 kg/m2   the total production of broiler chickens was decreased by 6022.5 and  8959.5 kg live weight respectively. The concentration of birds per unit area of ​​25.76 and 23.90 kg/m2 lead to lower the  price of the product of broiler chickens by 4745.73 and 7060.09 € respectively, compared with  the price for the product of the concentrations of 29.41and  29.33 kg/m2 respectively.

Short- and long-term movement patterns in complex confined environments in broiler chickens: the effects of distribution of cover panels and food resources

In captivity, the positioning of structural enrichment and food resources influences behavior and space use. The aim of this experiment was to examine the influence of cover panels and the positioning of food resources on the movement and space use of domestic fowl (Gallus gallus domesticus). Eight groups of 45 male chickens were used for this study. Each group was temporarily divided into 2 groups of 20 birds; each group was used to investigate the influence of cover panels and the effects of food resources. In the cover panel treatments, 20 birds were placed in the 10-m(2) testing enclosures that contained one 2-m cover panel in the center, four 0.5-m panels in a zigzag fashion, or had no panels (controls). In the food resource treatments, the position of the feed trays varied, with 1 feed tray in the center; 2 feed trays, one at each edge; or 4 feed trays, one at each corner of the enclosure. Locations of focal birds were collected through instantaneous scan sampling that was recorded as X,Y coordinates. From these X,Y coordinates, we calculated net and total distance moved, mean and maximum step lengths, and angular dispersion of the path of movement. To calculate long-term space use, 3 replications for each of 3 cover panel and food resource treatments were placed in nine 10-m(2) enclosures for 1 wk. Locations of focal birds in each group were collected by ad libitum scan sampling and data were used to calculate core areas by kernel estimates. Mixed model ANOVA was used to determine the effects of the distribution of cover panels and positioning of food resources on movement parameters during the study period, whereas 1-way ANOVA was used for core areas. Surprisingly, our analyses showed that long-term and short-term movement was not affected by changing the location of cover panels or food resources. Only net distance seemed to be affected to a certain degree by the presence of the cover and the distinctive availability of food resources.

Separating the impact of group size, density, and enclosure size on broiler movement and space use at a decreasing perimeter to area ratio

The goal of this study was to determine the impact of enclosure size on space use and movement patterns of domestic fowl (Gallus gallus domesticus), independent of group size and density. Research designed to estimate the effects of group size, density, or enclosure size involves inherent confounding between factors, clouding their individual effects. This experimental design enabled us to conduct multiple contrasts in order to tease apart the specific impacts. Treatments consisted of five combinations of three square enclosures: small (S; 1.5m(2)), medium (M; 3.0m(2)), and large (L; 4.5m(2)), and three group sizes of 10, 20, and 30 birds. We made comparisons while holding group size constant, holding density constant, and the third while maintaining a constant enclosure size. Nearest neighbor distances increased with enclosure size but appeared to be constrained by density. Net displacement and minimum convex polygons increased with enclosure size regardless of group size or density. We found no evidence of social restriction on space use. Results indicate that broilers adapted their use of space and movement patterns to the size of the enclosures, spreading out and utilizing a greater amount of space when it was available.