Enriched Cages Research Articles

Effect of housing environment and hen strain on egg production and egg quality as well as cloacal and eggshell microbiology in laying hens

This study was conducted to determine the effect of housing environment and laying hen strain on performance, egg quality, and microbiology of the cloaca and eggshell. A total of 1,152 Hy-Line Brown (HB) and Hy-Line W-36 White Leghorn (W-36) hens were used. All hens were kept in conventional cages (CC) from 18 to 32 wk of age and then moved to either enriched colony cages (EC) or free-range (FR) pens or continued in CC. Hens were randomly allocated into a 2 × 3 factorial arrangement of 2 laying hen strains (brown and white) and 3 housing environments (CC, EC, and FR) in a split plot in time (hen age) design. The experiment was conducted from 32 to 85 wk of age. The experiment was divided into 2 phases: early phase (32–51 wk of age) and late phase (52–85 wk of age). A 3-way interaction was observed for hen day egg production (HDEP) among housing environments, hen strain, and bird age in the early phase (P = 0.004) as well as in the late phase (P < 0.0001). In both of the phases, HDEP was higher in CC and FR than in EC. Hy-Line W-36 hens raised in EC had the lowest HDEP compared to other treatments. A 3-way interaction was observed for feed intake (FI; P = 0.017) and feed conversion ratio (FCR) in the late phase (P < 0.0001). The lowest FI and highest FCR were observed in EC for W-36 hens. Free-range hens performed in-between for eggshell quality when compared to CC and EC while HB had better egg quality than W-36. Free-range hens had higher cloacal bacterial counts for aerobes, anaerobes, and coliforms than CC and EC. Higher eggshell bacterial contamination was observed in eggs from FR versus eggs from CC and EC. These results indicate that both housing environment and laying hen strain affect performance and egg quality as well as cloacal and eggshell microbiology. Further studies should be conducted to determine food safety and economic impacts when using different hen strains and housing environments.

The effects of cage type, oviposition time and egg storage period on the egg quality characteristics of laying hens

Egg has valuable nutrients however; these nutrients may be affected by many factors. In this study, it was aimed to determine the effects of cage type, oviposition time and egg storage period on egg quality characteristics of laying hens. A total of 410 eggs were collected from unenriched and enriched cages in the morning and in the afternoon. After the eggs were weighed, they were stored at 21oC and 20% relative humidity until the 30th day of storage. It was determined that unenriched cage eggs had higher in shell breaking strength, albumen ash and pH &amp;amp; lipid of yolk and lower egg weight loss, yolk index &amp;amp; yolk color compared with enriched cage eggs. Morning eggs had the highest egg weight loss and the lowest egg weight, yolk height and yolk diameter. Dry matter &amp;amp; protein of albumen and dry matter &amp;amp; lipid of yolk were lower, while protein of yolk was higher in the morning eggs than those in the afternoon. It was observed that the storage period was important factor for egg quality characteristics. The effect of oviposition time and storage period interaction on egg quality should not be neglected. Interactions between cage type and storage period and between oviposition time and storage period were found statistically significant for some chemical composition of albumen and yolk. It is concluded that A quality egg criteria are preserved up to 14 days at an average temperature of 21°C and 20% humidity.

Behavioral Changes of Solitary Housed Female Pygmy Slow Lorises (Nycticebus pygmeaus) after Introduction into Group Enclosures.

Simple SummaryMost pygmy slow lorises confiscated in the illegal pet trade cannot be released back into the wild and end up in captivity for the rest of their lives. In the wild, their home ranges are large relative to their body size and they maintain a fairly solitary lifestyle compared to other primates. With the aim of improving their captive wellbeing, we tested to see whether female–female group pairings were in the animals’ best interest by looking at their behaviors before and after being moved to social housing in a larger enriched enclosure. With one nesting site per animal and ample space to avoid each other, all females opted to nest in pairs, not alone, and spent their time socially engaged in affiliative behaviors. We found that female pygmy slow lorises are more social than often assumed and that housing them with conspecifics is probably beneficial to their well-being in captivity.Pygmy slow lorises (Nycticebus pygmaeus) are threatened with extinction in the wild. Their nocturnal lifestyle and small size make them difficult to study in their natural habitat, but increasing evidence suggests that they are more social than previously thought. Our study was designed to assess the sociability of pygmy slow lorises by transferring six adult females from solo cages into environmentally enriched group home cages at the Japan Monkey Centre’s Slow Loris Conservation Centre. Two females were paired to create one group, while the other four were placed together in a second group. We compared their social interactions, activity budgets, and postural behaviors before and after social housing was initiated. We found that all-female slow loris groups had a high degree of sociality, preferred to stay close to each other, nested together every night, and spent less time in locomotion and more time grooming than when living alone. These results suggest that female pygmy slow lorises actively seek companions when available. The captive housing of all-female groups of lorises could lead to better husbandry practices and improved animal welfare by allowing them to have conspecific companions. We conclude that isosexual groups of pygmy slow lorises should be preferred over single housing when possible.

Life cycle assessment of contemporary Canadian egg production systems during the transition from conventional cage to alternative housing systems: Update and analysis of trends and conditions

The supply-managed Canadian egg industry produces over 789 million dozen eggs per year, the majority of which are produced in conventional cages (∼60%). Recently, the industry committed to a complete transition to alternative (i.e. enriched cage, single- and multi-tier free run, free range, and organic) production systems by 2036. This transition may have significant sustainability implications. Here, we present updated (i.e. based on 2019 data) LCA models and results representing the cradle to farm gate environmental impacts of Canadian egg production systems based on a much expanded data set compared to previous models.Generally, input and emission levels decreased across all housing systems, with few exceptions, compared to previously reported levels. Acidifying and GHG emissions decreased across most housing systems due to increases in feed- and pullet-use efficiency, while eutrophying emissions increased across all housing systems modeled due to differences in manure management systems. Feed inputs represented the greatest contributor to most impact categories (∼18% - 84%), followed by pullet production and manure management (∼ 10% - 37% and ∼0.01% - 62%, respectively). Organic production systems had the lowest impacts in nine of the ten categories assessed, while free range systems generally performed the worst. Conventional cages generally had lower impacts than all non-organic systems. However, it can be expected that as farmers gain experience with alternative systems resource-use efficiency levels will increase and environmental impacts will decrease. Continued monitoring of environmental performance of Canadian egg production systems is therefore imperative to ensure net-positive outcomes during this housing system transition.

Maternal age and maternal environment affect stress reactivity and measures of social behaviour in laying hens

Maternal effects can shape the phenotypes of offspring, but the extent to which a layer breeder’s experience can affect commercial laying hens remains unclear. We aimed to investigate the effects of maternal age and maternal environment on laying hens’ behaviour and stress response. In our first experiment (E1), commercial hybrid hens were reared either in aviary or barren brooding cages, then housed in aviary, conventional cages or furnished (enriched) cages, thus forming different maternal housing treatments. Hens from each treatment were inseminated at three ages, and measures of response to manual restraint and social stress were assessed in offspring. In experiment 2 (E2), maternal age effects on offsprings' stress response were further investigated using fertile eggs from commercial breeder flocks at three ages. In E1, maternal age affected struggling and corticosterone during manual restraint, feather pecking and pulling and comb wounds. Additionally, maternal rearing and housing in aviary systems showed positive effects on measures of behaviour and stress response in offspring. Effects of maternal age were not replicated in E2, possibly due to methodological differences or higher tolerance to maternal effects in commercial breeders. Overall, we recommend researchers report parent stock age to increase comparison across studies and thus our understanding of maternal age effects.

Effects of Different Scratch Mat Designs on Hen Behaviour and Eggs Laid in Enriched Cages.

Simple SummaryEnriched cages for laying hens must contain litter so that pecking and scratching are possible. This is typically provided using layer’s feed dispensed onto a scratch mat, however, there are no regulations on the size or materials of the mat. This study examined how different scratch mat designs and bird age affected behaviours on the mat at three times of day, and their influence on where eggs were laid and shell quality. The proportion of hens at the scratch mats did not increase during or shortly after the application of scratch feed, however, they were more likely to be foraging then. Most eggs collected were clean and laid in the nest. Of the small proportion of eggs that were cracked or dirty, the mat type did not affect dirty eggs, but eggs laid opposite the Big Dutchman mats were more likely to be cracked at 79 weeks of age than at any other mat type or age. There appeared to be no optimal scratch mat design (of those studied) and their use (during observations) was low, suggesting that mat designs were not major influencers on bird behaviour.Laying hens in the UK and EU must be provided with litter for pecking and scratching. In enriched cages, this is commonly provided by dispensing layer’s feed onto a scratch mat. Mats vary in design and size, which might affect hen behaviour and egg quality, since eggs are sometimes laid at the mats. We investigated if four different scratch mats (BD, K, V, Z) provided to hens in enriched cages resulted in differences in behaviour on the mats and external egg quality. Twenty-four 60-bird cages (6 cages/bank × 4 banks) with 2 mats/cage at one tier of a commercial enriched cage unit were used. Mats were allocated to cages in a balanced design prior to the flock arriving. Hens and eggs were studied at 30, 50 and 79 weeks of age, with three behaviour observations (before, during or after scratch feed application). The data were analysed by GLMMs or LMMs. The vast proportions of birds on the mats were standing (0.720) or sitting (0.250). Bird proportions on the mats were low overall and declined from 0.028 (30 weeks) and 0.030 (50 weeks) to 0.020 (79 weeks) (p < 0.001). The greatest proportion of hens were observed on Z (p < 0.001), which had the largest area, but relative to the available area least birds were on Z and most were on K (p < 0.001). Foraging was not affected by bird age or mat type but was greater at the second observation (p < 0.001). Most eggs were laid in the nest box and were clean. Clean eggs declined, and dirty eggs increased, significantly with age, particularly at the scratch mat (p < 0.001). Dirty eggs were not affected by mat design. Cracked eggs were highest at 79 weeks of age, particularly with BD mats (p < 0.001). Overall, scratch mat designs had minimal effects on behaviour (but few hens were seen there) and egg quality.

Boredom-like exploratory responses in farmed mink reflect states that are rapidly reduced by environmental enrichment, but unrelated to stereotypic behaviour or ‘lying awake’

Consistent with boredom, prior work has found that mink raised in non-enriched (NE) or enriched (E) conditions differ in their motivations to seek stimulation: NE mink spent more time oriented towards and in contact with diverse stimuli presented to them (ranging from rewarding to aversive), and in one study, NE mink showed shorter latencies to contact these stimuli and consumed more treats (Meagher and Mason, 2012; Meagher et al., 2017). Here, in Study A, we used a new population of young adult males (n = 30) to test the hypothesis that this reflects boredom-like states rather than long-lasting traits, being rapidly reversed by access to more stimulating environments. Minks’ exploration of stimuli was tested after seven months in minimally enriched control cages (containing a wiffle ball and shelf), and re-tested a median of six days after half the mink were moved to larger cages that were enriched with rewarding items. Although latencies to contact stimuli (F1, 27.42 = 0.23, p = 0.32) and proportion of treats consumed (F1, 27.45 = 0.44, p = 0.26) were not reduced by access to enriched housing, contact durations were (F 1,29.11 = 14.23, p = <0.05) and orientation times tended to be (F 1, 29.22 = 2.37, p = 0.07). Boredom-like exploration in farmed mink thus reflect states that are rapidly reduced by environmental enrichment. Enrichment-access also significantly reduced stereotypic behaviour (SB; z = 3.81, p = <0.05), although lying awake (another potential boredom-like indicator) unexpectedly increased (z = −4.15, p = <0.05). However, the reduction of SB did not correlate with reductions in exploration (F1,12 = 0.73, p = 0.41), indicating that SB and boredom-like states are independent. In Study B, we pooled data from all three populations studied to date, to re-test all hypotheses with greater power (N = 79). This revealed no significant associations between exploration of stimuli and SB, nor with lying awake. Furthermore, only contact and orientation durations were consistently lower in enriched housing (F1,72 = <45.50, p = <0.05), suggesting that these measures are most sensitive to motivations to seek stimulation. Overall, Study B shows that baseline time-budgets of SB and lying awake cannot reliably be used to identify boredom-like states in mink. However, Study A supports the hypothesis that increased exploration of diverse stimuli by captive animals in unstimulating housing reflects transient, reversible boredom-like states (not long-lasting traits).

Ameliorative Effects of Enriched Environment and Chronic Administration of Aqueous-methanol Extract of Garlic (Allium sativum) on Mice Models of Depression

Depression is a state of mood or energy level that includes lack of motivation, a sense of hopelessness and a loss of physical energy. The World Health Organization revealed that depression is one of the leading causes of ill health and disability worldwide. More than 300 million people are living with depression. Many of the currently available antidepressant drugs have proven to be effective but they are burdened with some disadvantages such as various adverse effects, problematic interactions and relatively low response. Therefore the need to utilize a natural agent in the management of depression is paramount. The aim of this study was to investigate the effects of chronic administration of extract of Allium sativum and Enriched environment in depression. 42 albino mice were used and divided into seven groups of five mice each. Group 1 was given distilled water; groups 2 and 3 received 200 mg/kg and 400 mg/kg of aqueous extract of Allium sativum respectively; while groups 4 and 5 were in addition to receiving 200 mg/kg and 400 mg/kg of the extract, housed in an enriched cage. Group 6 was only housed in an enriched cage and group 7 receives 10 mg/kg of imipramine. The experiment lasted for six weeks after which Force Swimming Test, Tail Suspension Test and Sucrose Preference test were conducted. The mice were sacrificed and their brain isolated, homogenized and centrifuged. The supernatant was used for biochemical assays (MDA, SOD, GPx, BDNF &amp; TNF-α). The results showed that Allium sativum and Enriched Environment helped in mitigating depressive disorders. Therefore, conducive environment and garlic extract could be used in the management of depression.

Egg Production Systems, Open Space Allowance and Their Effects on Physical Parameters and Fatty Acid Profile in Commercial Eggs.

Simple SummaryAnimal welfare is a major concern in consumer’s decision about animal products. Nowadays it is possible to find eggs produced in various systems closer or not to hens’ specific behavioural requirements. In this study we compared physical characteristics and fatty acid profile (being the nutritional value of the egg intimately linked to its lipids content) in four differently labelled eggs according to the production system: enriched cage, alternative (small outdoor area), litter floor and organic (large outdoor area). We found many significant differences in both physical characteristics and fatty acids profiles as an effect of the production system and the outdoor space availability.Food function is nowadays not merely limited to nourishment supplying; consumers’ interest is oriented to food healthiness and nutritional value, animal welfare, environmental impact of animal productions, and products’ traceability. The objective of the present work is to compare physical parameters and fatty acids profiles of market eggs produced from hens housed in four different systems. In addition, the effects of the presence of an outdoor space allowance (IND = no outdoor space allowance, OUT = outdoor space allowance) on the same parameters have been investigated. Sixty-nine market eggs from four different production systems labelled as Alternative (ALT), Enriched Cage (ECA), Litter Floor (LIF), and Organic (ORG) have been analysed. Physical parameters and fatty acid concentrations were measured. An ANOVA analysis was performed with production system and outdoor space allowance as sources of variation, two Principal Component Analyses (PCA) were carried out with physical parameters and fatty acid parameters as variables. The effects of the complex interactions occurring among production system, hen welfare, and eggs quality have been analysed in marketed eggs leading to the conclusion that eggs from different production systems available on the market are characterized by differences in fatty acid profile and physical parameters. In physical parameters the differences among systems were influenced by the whole egg weight, albumen weight and yolk weight. In fatty acids parameters the determining variables are the content in polyunsatured fatty acids (PUFA), linoleic acid concentration, and n6/n3 ratio.

Effects of the housing environment and laying hen strain on tibia and femur bone properties of different laying phases of Hy-Line hens

This study aimed to determine the effect of the housing environment and laying hen strain on tibia and femur properties. A 3 × 2 factorial arrangement of 3 housing environments (conventional cages [CC], enriched colony cages [EC], and free range [FR]) and 2 laying hen strains (Hy-Line W-36 [W-36] and Hy-Line Brown [HB]) in a completely randomized design was conducted from 32 to 85 wk of age. Six left tibias were collected at 8 different time points (38, 45, 52, 59, 65, 72, 79, and 85 wk of age), whereas 6 left femurs were collected at 3 time points (38, 65, and 85 wk of age). Tibias were evaluated for tibia breaking strength (TBS) and ash percentage, whereas femurs were evaluated for bone mineral density (BMD), bone mineral content, bone volume as a fraction tissue volume, and porosity percentage from total, cortical, medullary, and trabecular bones. The higher TBS (P = 0.0005) and ash percentage (P = 0.045) was observed in hens raised in FR systems compared with those raised in the CC. Overall, TBS of W-36 hens was significantly greater than that of HB hens (P < 0.0001); however, there was no difference in the ash percentage between the strains (P > 0.05). An interaction between the housing environment and hen strain was observed for BMD (P = 0.04), wherein W-36 hens raised in the FR system had higher BMD than HB hens. Similarly, hens raised in FR systems had higher trabecular bone volume than those raised in CC (P = 0.022). Hen strain influenced total and cortical bone properties: BMD, bone volume as a fraction tissue volume, and porosity percentage, wherein W-36 hens had better properties than HB hens (P < 0.05). Trabecular BMD was higher in W-36 hens than in HB hens (P = 0.04), whereas bone volume was higher in HB hens (P < 0.0001). The results suggest that raising laying hens in alternative housing systems that have provision for exercise such as FR reduces structural bone loss, stimulate structural bone formation, and improve breaking strength of bones; however, it varies with the strain.

Where are you from? Female mice raised in enriched or conventional cages differ socially, and can be discriminated by other mice

Laboratory rodents raised in environmentally-enriched (EE) cages differ behaviourally and cognitively from conventionally-housed (CH) animals. We hypothesised that mice can detect such differences, testing this using differentially-raised female C57BL/6 s as subjects, and differentially-raised female BALB/cs and DBA/2 s as stimuli, in Social Approach Tests. Because more prone to signs of depression, anxiety, stereotypic behaviour (SB) and aggression, we further hypothesised that CH mice would be less sociable and socially attractive than EE mice. A novel familiarisation paradigm pre-exposed subjects to non-cagemate EE and CH stimulus mice before testing in Social Approach Tests. CH subjects proved less sociable than EE subjects: an effect unrelated to general exploration, anxiety or depression-like traits, and driven specifically by reduced interest in CH stimulus mice. Providing further evidence that CH and EE stimulus mice could be distinguished, subjects proved most attracted to mice from housing unlike their own. CH subjects thus preferred EE over CH stimulus mice, while EE subjects tended to prefer CH over EE: patterns that were not mediated by any measured aspect of stimulus mouse behaviour. Differential bodyweight also seemed unimportant, as was scent: soiled CH and EE bedding/nesting did not elicit the same discrimination. Instead, subjects who avoided CH stimulus mice and were attracted to EE stimulus mice were those who received the most agonism in their home cages. Together this provides the first demonstration that mice can distinguish between individuals raised in enriched or conventional cages, and suggests that receiving agonism from cagemates may motivate mice to seek new, less aggressive companions.

Combined Effect of Genotype, Housing System, and Calcium on Performance and Eggshell Quality of Laying Hens.

Simple SummaryHen performance and eggshell quality are affected by a wide range of factors from which genotype. The housing conditions and feed calcium (Ca) level might be considered the most important. Here, we compared the performance and eggshell quality of commercial hybrids (ISA Brown, Bovans Brown) and traditional Czech hybrid (Moravia BSL). Laying hens were housed in enriched cages and on littered pens and fed two different Ca levels (3.00% vs. 3.50%). Contrary to the commercial hybrids, Moravia BSL performed better under the lower feed Ca level in enriched cages. Additionally, the data pointed out the importance of studying the interaction between factors, which might help to decide the best housing system and feed Ca level for a certain hen genotype.The objective of this study was to evaluate hen performance and eggshell quality response to genotype, housing system, and feed calcium (Ca) level. For this purpose, an experiment was conducted on 360 laying hens of ISA Brown, Bovans Brown (commercial hybrids), and Moravia BSL (traditional Czech hybrid). Laying hens were kept in enriched cages and on littered floor and fed similar feed mixtures with different Ca content (3.00% vs. 3.50%). In terms of hen performance, ISA Brown had the highest egg production (84.2%) compared to Moravia BSL (74.3%) and Bovans Brown (71.4%). Regarding eggshell quality, Bovans Brown showed the highest values of all eggshell quality parameters. Increasing feed Ca level augmented egg production (p ≤ 0.001) but had no effect on other performance parameters. Except eggshell thickness, all eggshell quality parameters were affected by the three-way interaction of genotype, housing, and Ca. Bovans Brown, which had the strongest eggshells (5089 g/cm2) when housed on a littered floor system and fed 3.00% Ca, while Moravia BSL housed on a littered floor had the weakest eggshells (4236 g/cm2) at 3.50% Ca. The study pointed out the importance of the interactions between studied factors on performance and eggshell quality compared to an individual factor effect.

BALB/c female subjected to valproic acid during gestational period exhibited greater microglial and behavioral changes than male mice: A significant contra intuitive result.

Most animal model studies of autism spectrum disorders (ASD) were performed in males. Thus, little is known about the mechanisms underlying disease progression in females. Here, we searched for potential influences of sex and environment on gestational valproic acid-induced behavioral abnormalities using hippocampal-dependent tasks, and on number and morphometry of microglia of the molecular layer of the dentate gyrus (Mol-DG). We compared male and females BALB/c control mice with BALB/c mice gestationally exposed to VPA with regards to exploratory activity and risk assessment in novel environments. Pregnant females and males on gestational day 12.5 received VPA in saline (600mg/kg body weight) or an equal volume of saline by gavage. After weaning, female and male offspring were housed separately either in standard laboratory cages (SE) or enriched cages (EE). At 5months of age, these mice underwent behavioral testing and had their brains processed for microglia IBA1 immunolabeling. Compared with control mice, VPA-exposed mice exhibited abnormal behavior in exploring novel environments and assessing risk, and these effects were significantly greater in females than in males and less intense among mice from enriched cages. Three-way ANOVA revealed that environment, sex and valproic acid conditions interacted and altered the behavior results. Microglia number and volume of the Mol-DG were significantly higher in VPA-exposed groups raised in standard cages. The results of counting the intersects of microglia branching on Sholl's circles analyzed with permutational MANOVA, demonstrated that in comparison with males, there was a greater reduction in the number of intersections in females raised in standard cages. These findings suggest that the increased microglia and morphological changes might be associated with behavioral dysfunction in ASD. Moreover, the somatomotor and cognitive stimulation of environmental enrichment started at weaning may be beneficial for reducing behavioral abnormalities and reduction of microglia response in adulthood.

Performance of Rhode Island Red, Black Australorp, and Naked Neck crossbreds under alternative production systems

The effects of the production system, breed cross, and their interaction on performance, egg quality, and hatching traits were evaluated. Rhode Island Red and Black Australorp were crossed with Naked Neck chickens (first generation RNN, and BNN, respectively). These crosses were mated among themselves and crossed to produce four crossbreds: RR (RNN x RNN), BB (BNN x BNN), RB (RNN x BNN), and BR (BNN x RNN). Thirty-six pullets and 9 cockerels from each crossbred were maintained in three production systems: the aviary system (AV), conventional cages (CC), and enriched cages (EC). Thus there were 48 pullets and 12 cockerels in each production system. Bodyweight, egg production percentage, and egg weight were highest in EC, followed by CC and AV. Higher egg weight, egg surface area, and egg volume were also observed in EC compared with CC and AV. Fertility and hatchability were higher and early embryonic mortality was lower in AV than in EC and CC. Bodyweight, egg production percentage, egg weight, egg volume, and surface area were higher for RB and BR than for BB and RR. Fertility and hatchability were similar for RB and BR. RR was similar to BR, but lower than RB. BB had the lowest fertility and hatchability. Thus, chickens in EC performed better than in the other systems, except that hatching traits were better in AV. RB and BR performed better than BB and RR.Key words: breed crosses, chicken, egg quality, hatchability

Effects of environmental enrichment on growth performance, carcass traits, meat quality, and hair follicle development of Rex rabbits.

ObjectiveThe purpose of this study was to investigate growth performance, carcass traits, meat quality and hair follicle development of growing Rex rabbits as affected by different environmental enrichment materials.MethodsA total of one hundred and twenty Rex rabbits were randomly assigned to four groups; reared in conventional cages (not enriched) and in enriched cages with either willow stick (WS), rubber duck, or a can containing beans (CB), for 44 days.ResultsThe average daily gain of the CB group was the highest and had a significant difference from that of the other groups (p<0.05). The spleen and cecum weight of the CB group was greater than those of the WS and control groups (p<0.05). The redness (Commission Internationale de l’Eclairage a*) of the meat sample of the control group was lower than those of the enriched cage groups (p<0.05). Moreover, the hue value of the CB group was significantly lower than that of the other groups (p<0.05). The tenderest meat belonged to the CB group. In addition, more secondary (p<0.05) and primary follicles were found in the CB group than in the control group.ConclusionEnvironmental enrichment increased the average daily gain and improved some carcass traits, meat quality, and hair follicle density. Among the three environmental enrichment materials, CB could be recommended for rabbit husbandry.

Changes in Day/Night Activity in the 6-OHDA-Induced Experimental Model of Parkinson's Disease: Exploring Prodromal Biomarkers.

The search for experimental models mimicking an early stage of Parkinson’s disease (PD) before motor manifestations is fundamental in order to explore early signs and get a better prognosis. Interestingly, our previous studies have indicated that 6-hydroxydopamine (6-OHDA) is a suitable model to induce an early degeneration of the nigrostriatal system without any gross motor impairment. Considering our previous findings, we aim to implement a novel system to monitor rats after intrastriatal injection of 6-OHDA to detect and analyze physiological changes underlying prodromal PD. Twenty male Sprague-Dawley rats were unilaterally injected with 6-OHDA (n = 10) or saline solution (n = 10) into the right striatum and placed in enriched environment cages where the activity was monitored. After 2 weeks, the amphetamine test was performed before the sacrifice. Immunohistochemistry was developed for the morphological evaluation and western blot analysis to assess molecular changes. Home-cage monitoring revealed behavioral changes in response to 6-OHDA administration including significant hyperactivity and hypoactivity during the light and dark phase, respectively, turning out in a change of the circadian timing. A preclinical stage of PD was functionally confirmed with the amphetamine test. Moreover, the loss of tyrosine hydroxylase expression was significantly correlated with the motor results, and 6-OHDA induced early proapoptotic events. Our findings provide evidence for a novel prodromal 6-OHDA model following a customized monitoring system that could give insights to detect non-motor deficits and molecular targets to test neuroprotective/neurorestorative agents.

Effects of cage type on performance, welfare, and microbiological properties of laying hens during the molting period and the second production cycle.

As most of the unenriched cages will soon switch to enriched cages, it is important to characterize all the effects in the laying hens for sustainable production. Laying hens can be used in several production periods by applying molting. The aim of this study was to determine the cage type (unenriched and enriched) on performance, welfare, and microbiological properties of laying hens during the molting period and the second production cycle. Overall, 840 brown laying hybrids were used in the experiment. Laying hens were reared on two different cage types (unenriched cage (UEC) and enriched cage (EC)) in the same poultry house. When the hybrids were 75weeks old, they were subjected to force molting with whole grain barley. Performance, welfare, microbiological, and serological data of laying hens were obtained from 73 to 107weeks of age. Egg production, egg weight, feed conversion ratio, breaking strength, albumen and yolk index, Haugh unit, feather condition, and breaking force of femur and metatarsus were better in the post-molting period. However, keel bone deformities and Newcastle disease virus antibody titers are the worst in the post-molting period. Stiffness of femur and metatarsus was increased with period. These results indicate that necessary precautions should be taken against the problems that may occur in the direction of bone and health. During the molting period, hens kept in EC had lower egg production but they returned to egg production at a high rate. EC type had a positive effect on egg production, feed conversion ratio, feather and foot condition, and breaking force of metatarsus.

Long-term environmental enrichment reduces microglia morphological diversity of the molecular layer of dentate gyrus.

We investigated long-term environmental influences on morphology of microglia from the outer and middle thirds of molecular layer of the dentate gyrus (MolDG), and on microglia from dorsal and ventral dentate gyrus molecular layer. We also estimated the total number of MolDG microglia using stereology. For this purpose, microglia of the molecular layer of the dentate gyrus of 20-month-old female Swiss albino mice, housed from 21st postnatal day onwards, in the impoverished environment of the standard laboratory cages (SEA), or in a cage with an enriched environment (EEA), were reconstructed microscopically in three dimensions and compared with each other and with microglia of 6-month-old female Swiss albino mice, also housed from weaning onwards in an enriched cage (EEY). All mice had their brains sectioned and processed for immunolabeling for IBA-1, a selective microglia marker. Random and systematic microglia samples were reconstructed in three dimensions and classified morphologically using hierarchical cluster analysis, followed by discriminant function analysis. SEA and EEY showed two morphological phenotypes of microglia in both the outer and middle thirds of MolDG. EEA mice showed such a reduction in the morphological diversity of microglia that essentially a single morphotype was found. EEA mouse microglia showed an intermediate morphological complexity between types I and II SE microglia. We suggest that type I and type II microglia in SE mice may have different physiological roles and that long-term EE may be associated with adaptive responses of microglial phenotypes to somatomotor and cognitive stimuli.

Effects of Dimethyl Anthranilate-Based Repellents on Behavior, Plumage Condition, Egg Quality, and Performance in Laying Hens.

Feather pecking is a behavior that occurs in order to cope with a constrained environment and is a serious problem in the egg production industry. This longitudinal study was conducted under commercial conditions to investigate whether the application of two repellent mixtures, previously suggested as aversive to wild birds, to the plumage of Prelux-R hybrid egg layers is a viable alternative to beak trimming as a solution to discourage feather pecking among laying hens. A total of 180 untrimmed hybrid layers was reared together in a floor pen. At 18 weeks of age they were allocated randomly to three treatments (repellent P, repellent T, control), each consisting of 6 replicated enriched cages with 10 hens in each cage. Hens were evenly sprayed once every 2 weeks for 54 weeks with solution P (dimethyl anthranilate and methyl phenylacetate), solution T (dimethyl anthranilate and geraniol), or distilled water (control). Body weight, plumage condition, behavior, feed intake, and egg quality measurements were taken at five time periods from 26 to 76 weeks of age. Egg production and mortality were recorded daily. The treatments did not affect feather pecking behavior. Hens treated with repellent T tended to perform less cage pecking than the control hens. The use of the repellents did not reduce feather pecking, the plumage was even more significantly damaged in the hens given the repellents compared to the control hens. This suggests the chemicals in the repellents worsened the plumage. No differences in feed intake and daily egg production between treatments were found. Raw and hard-boiled eggs were highly uniform in odor/flavor/taste and no offensive odor absorption related to the chemicals in the repellents was detected. In conclusion, in the present study we did not find any beneficial effect of dimethyl anthranilate-based repellents on feather pecking frequency and plumage/feather condition. Therefore, we do not encourage their use in wider commercial settings.

Pullet Rearing Affects Collisions and Perch Use in Enriched Colony Cage Layer Housing.

Simple SummaryEarly-life experiences for laying hens occur in the pullet rearing environment. Hens reared in aviaries use vertical space more than hens reared in non-enriched cages, but this effect has only been studied up to 23 weeks of age. Additionally, hens reared in aviaries sustain fewer keel bone fractures than those reared in non-enriched cages through the age of 73 weeks. Fractures are associated with hens having collisions with structures in their environment, but the long-term effect of rearing on collisions is not known. Lohmann LSL-Lite hens were reared in either aviaries or non-enriched cages until 19 weeks of age, then moved into enriched colony cages. Video recordings at 21, 35, and 49 weeks of age were used to identify behaviors associated with acceleration events for hens fitted with tri-axial accelerometers, as well as the proportion of birds utilizing elevated perches at two different heights. Our results indicate that hens reared in non-enriched cages experience more collisions than aviary-reared hens. Aviary-reared hens also prefer to utilize a higher perch than the cage-reared hens. These results suggest that rearing has long-term effects on space use and the ease with which hens transition among vertical spaces.Hens reared in aviaries (AVI) as pullets have improved spatial abilities compared to hens reared in non-enriched cages (CON). However, this effect on behavior has been shown only to 23 weeks of age. Lohmann LSL-Lite hens were reared in either CON or AVI until 19 weeks of age and then moved into enriched colony cages (ECC) containing two elevated perches of different heights (n = 6 ECC/treatment). Focal hens (3 per ECC) were fitted with tri-axial accelerometers to record acceleration events at 21, 35, and 49 weeks of age. Video recordings from each age were used to identify behaviors associated with acceleration events as well as the proportion of hens utilizing perches. CON hens experienced more acceleration events (p = 0.008) and more collisions (p = 0.04) than AVI hens during the day at 21 and 35 weeks of age. The total proportion of hens perching at night was similar between treatments across most time points, but fewer CON hens used the high perch compared to AVI hens throughout the study (p = < 0.001). Rearing in aviaries influences hen behavior out to peak lay for collisions and out to mid-lay for perch height preference in ECC.