Enriched Cages Research Articles

Dietary stinging nettle (Urtica dioica) improves carotenoids content in laying hen egg yolk

ABSTRACT 1. This study assessed the addition of dried stinging nettle (SN) leaves at 0%, 2.5% and 5.0% in feed on egg production, egg quality, chemical composition and antioxidant content in eggs from laying hens. 2. Seventy-two Hy-Line Brown laying hens, housed in 36 enriched layer cages, were used in the study from 43 to 47 weeks of age. Feeding dry SN leaves did not affect (p > 0.05) egg production variables. 3. Dietary SN inclusion linearly increased (p < 0.001) carotenoid content more than six-fold, in addition to yellowness and redness of the yolks at the maximum inclusion. Providing eggs from hens fed carotenoid enriched diets, e.g. SN, may be used to increase carotenoids in human diets.

Occurrence of Salmonella spp. in flocks of laying hens in different housing systems in eastern Croatia from 2020 to 2023

Human Salmonella infections are often associated with the consumption of infected eggs and egg products. Therefore, knowing the prevalence of Salmonella spp. in flocks of laying hens and the factors that influence the occurrence of Salmonella on farms is of the utmost importance. Since 2012, housing laying hens in conventional cages has been prohibited in the European Union, and hens may only be kept in enriched cages or alternative housing systems. The prohibition of conventional cages has improved the welfare of laying hens, but has raised issues concerning the detrimental consequences for the spread and occurrence of infectious diseases in hen flocks. The aim of this study was to analyse the occurrence of Salmonella spp. in laying hen flocks in eastern Croatia in the period from 2020 to 2023, and to determine whether housing systems have an impact on occurrence. During this period, a total of 1534 samples of laying hen faeces from 191 flocks (106 flocks housed in enriched cages and 85 flocks in housing systems with closed outdoor runs) were tested at the Diagnostics Laboratory of the Croatian Veterinary Institute, Veterinary Department Vinkovci, as part of implementation of the National Salmonellosis Control Programme and official sampling in the Republic of Croatia for the presence of Salmonella spp. Isolation, identification and serotyping of Salmonella was conducted in accordance with the standard HRN EN ISO 6579-1:2017/A1:2020 method. Salmonella spp. was confirmed in the faeces of seven laying hen flocks (6.60%) housed in enriched cages, and 11 flocks (12.94%) of laying hens in housing systems with outdoor runs. The research results showed that there was no significant difference in the total occurrence of Salmonella between flocks of laying hens housed in housing systems with outdoor runs and those in enriched cages. The highest percentage of positive flocks was found in 2020 in 11.11% of flocks of laying hens housed in enriched cages and 18.18% of flocks of laying hens kept in housing systems with outdoor runs. When observed by county over the four-year study period, the percentage of positive flocks was significantly higher (P&amp;lt;0.05) in Brod-Posavina County in comparison with Osijek-Baranja County and Vukovar-Srijem County. The research results suggest that there is small possibility that transitioning from enriched cage systems to alternative housing systems, with strict biosecurity measure implementation, would increase Salmonella infections in laying hen flocks.

Egg authentication under seasonal variation using stable isotope analysis combined with machine learning classification

In the European Union (EU) eggs from laying hens are sold in different husbandry systems: enriched cage, barn, free-range and organic. An analytical distinction between the husbandry systems is of interest for the food control authorities, as fraudsters can make high profits by mislabelling the husbandry system of the eggs. In this study, a total of 180 hen's egg samples labelled to originate from barn, free-range and organic hens were taken from food retailers in Germany at monthly intervals over a period of 15 months. The eggs were analysed using stable isotope ratio analysis (IRMS) in order to identify potential influences of different husbandry methods. The analysis on a monthly basis showed that the feeding of the laying hens varied over the year, which makes it difficult to make a clear classification according to the type of husbandry. Temporary events such as the officially ordered poultry quarantine due to the avian influenza, had minor influence on the differentiation of the husbandry types. Various statistical models including linear discriminant analysis (LDA), random forest (RF) and multinomial logistic regression (Multinomial) based on a multi-element approach (δ13C, δ15N, δ34S) were used to classify the eggs according to the three types of husbandry. On average, the models achieved a correct classification of approximately 70%. The reduction of the prediction model to two classes (organic vs. conventional eggs) led to a correct classification of almost 80% across all samples. Additionally, significant differences in the mean values of the sulphur isotopes of the organic eggs showed a regional differentiation between Bavaria (southern Germany) and Schleswig-Holstein (northern Germany).

PSXIII-13 Evaluation of physiological functions and performance in laying hens in different housing systems

Abstract Egg production faces many challenges of economics, disease control and animal welfare concerns. Therefore, investigation of physiological characteristics in laying hens should be required for further discussion on such issues from a scientific point of view. In this study, we evaluated physiological functions and production parameters of hens raised in three different housing systems, conventional battery cage (CC), enriched cage (EC) and aviary system (AV). Lohmann Selected Leghorn Lite laying hens (n = 251) were used. At first, all the pullets were housed in CC. Then, a telemetric transmitter was implanted to randomly selected 18 hens on d 171 after birth to record electrocardiograms (ECGs), heart rate (HR), body temperature (BT) and locomotor activity (LA). Heart rate variability (HRV), which was analyzed using ECG, has been established as a suitable method for investigating autonomic nervous functions, and to assess stress and well-being of housing systems. On d 200 after birth, some of the hens were randomly selected and transferred to EC or AV (CC; n = 88, EC; n = 72, AV; n = 91), including hens implanted a transmitter (6 hens in each group). All parameters at 10 d before and 1 wk after the group division were compared. Egg laying rate (ELR), feed conversion ratio (FCR) and shell deformation were evaluated for egg production parameters. Hens were basically housed under the same management condition, and a constant light-dark cycle (light-on from 0300 to 1930 h). Feeding was conducted during light-phase, and water was supplied ad libitum. Statistical significance was defined as P &amp;lt; 0.05. Comparing the physiological parameter, HR during dark-phase and LA during light-phase after transferred to EC or AV were greater than those in CC. However, there was no significant difference in HR during light-phase or LA during dark-phase between CC and the other two groups. The high frequency (HF) power of HRV, which reflects parasympathetic nervous function, was high during the dark-phase (7.59 ± 1.56) and low during the light-phase (6.04 ± 0.78) in CC. This diurnal variation disappeared in EC or AV because the HF power during the dark-phase decreased. As for production, ELR, FCR and shell deformation were decreased after moved to AV, which were not found in other two groups after the group division. This study was conducted to clarify the effects of housing systems on the physiological functions and productivity of laying hens, and these results suggest that CC might provide hens with parasympathetic dominance with greater quality of rest in dark-phase, and AV causes the reduction of egg production. However, we cannot completely rule out the possibility that these results are influenced by movement to a different housing system. Therefore, further analysis should be performed to assess the relations between physiological functions, management and egg production.

PSVI-19 Abundance of some cecal bacteria in Lohmann LSL lite pullets and hens fed omega-3 fatty acids and yeast bioactives in low or high spacing allowance

Abstract Nutritional optimizations and rearing environment that meets welfare standards are prerequisite in the performance and health of laying hens. Rearing practices influence gastrointestinal development, microbiota, and immune function. However, little is known on the implications of rearing spacing allowance (SA) and feed ingredients on intestinal microbiota. We determined the abundance of selected cecal bacteria in pullets and hens in response to rearing SA and dietary omega-3 fatty acids (N-3 FA) and yeast bioactive (YB) from placement to 17 wk of age (woa). One-day old chicks (n = 2,632) were placed in cages in 2 SA of 24 cages each: High SA (HSA, 348 cm2/bird; ~50 birds/cage) and Low SA (LSA, 284 cm2/bird; ~68 birds/cage). Birds were fed corn and soybean-based diets (C), C + 3% co-extruded full fat flaxseed and pulse mixture (N-3 FA) and C + 0.05% YB processed with β-1,3-glucan hydrolase (YB). Birds were allocated to diets within SA according to 2 x 3 factorial design (n = 8 cage/treatment) and fed ad libitum. At 4 and 16 woa, 1 and 2 pullets/treatment respectively, were necropsied for ceca digesta from each cage and independently analyzed. At 18 woa, hens were placed in enriched cages based on rearing treatment identities in egg production facility and fed a commercial diet. At 35 woa, 18 hens per treatment were necropsied for ceca digesta samples and analyzed independently. Samples were analyzed for viable bacterial counts for E. coli, Enterococcus and Lactobacillus. Statistical analysis was performed by general linear mixed model procedures of SAS with diets, SA, sampling age and associated interactions as fixed factors, difference with P &amp;lt; 0.05 was considered significant. Comparison of log-transformed means (CFU/g) showed that diets and SA had no significant effect on cecal E. coli counts at 4, 8 and 35 woa (P &amp;gt; 0.05; Table 1). However, at 16 woa the least E. coli counts was found in LSA (P &amp;lt; 0.0001), with N-3-FA-fed and YB-fed pullets having fewer numbers (P = 0.007) than control-fed pullets. There was no interaction effects between diet and density for E. coli in all sampling wk (P &amp;gt;0.05). No significant effect of SA or diets were observed at any sampling week for Enterococcus counts, except LSA had a tendency at 8 woa (P = 0.078). At 8 woa, the cecal Lactobacillus counts (P = 0.009) were less in LSA relative to HSA pullets. In conclusion, feeding of N3-FA or YB during rearing influenced cecal microbiota. Supplementation of YB seemed to promote growth of beneficial Lactobacillus, which is associated with strengthened immunity.

The Effects of Rearing Systems on Incubation, Egg Production and Quality Traits in Pharaoh Quails

This study was conducted to determine the effect of rearing quails in different rearing systems on egg production, egg quality characteristics, and incubation results. The 360 quails were distributed equally to 3 different rearing groups (cage, enriched cage, and floor) in a male:female mixed at the age of 3 weeks. The eggs were individually weighed and recorded one by one daily (5487 eggs) for 3 months. To determine egg quality and incubation characteristics, 750 eggs were broken, and 3284 eggs were incubated, respectively. The results showed that female quail in the floor group have lower body weight at 6 weeks old (177.19 g), and they reached sexual maturity (age of first egg laying) later (65.36 day, P&lt;0.01), The lowest egg production (61.14%) occurred in the floor group during the 3-month egg production period (P&lt;0.05). The lowest average egg weight (9.07 g) was determined in the floor group (P&lt;0.05). It was determined that the eggs of quails raised in the enriched group had a rounder shape index because they have larger widths (P&lt;0.01). While the highest average yolk height (11.24 mm) was determined in the enriched cage group (P&lt;0.01), the highest averages of albumen length (72.41 mm) and lowest averages of yolk index (48.43%) were determined in the cage group (P&lt;0.01). The lowest average values (113.17) in Haugh unit were detected in the floor group (P&lt;0.05). The highest fertility rate (98.44%) was in Floor♂:Cage♀, the highest hatchability of fertile egg rate (94.67%) was obtained from Enriched♂:Cage♀, and the highest hatchability (89.10%) was obtained from Floor♂:Cage♀ pairing (P&lt;0.05). The lowest fertility rate (88.00%) was obtained from the Enriched♂:Floor♀, the lowest hatchability of fertile egg rate (86.01%) was obtained from the Enriched♂:Enriched♀, and the lowest hatchability (75.62%) was obtained from the Enriched♂: Enriched♀ groups. As a result, it has been revealed that the effect of various rearing systems is different on egg production, egg quality traits, and hatching results in quails. Thus, it has been shown that different programs at the rearing period to be applied to the male and female quails can achieve better incubation results and reproductive success.

Effects of housing systems on behaviour and welfare of autochthonous laying hens and a commercial hybrid

The welfare of laying hens is crucial for a sustainable and ethical food industry. Free-range systems offer a more natural and stimulating environment, while dual-purpose autochthonous breeds and crossbreeding could address ethical concerns and improve productivity. In this study, behaviour, plumage status, and leg health of five genotypes (two local breeds, two crossbreeds with a medium growth hybrid, and one commercial hybrid) in two different housing systems (enriched cage/free-range) were evaluated. The animals were filmed with professional cameras for three consecutive days at 30 and 64 weeks of age. Each day the recording session lasted 20 minutes, resulting in a total of 120 minutes per pen (20 min X 6 days recorded). A total of 16 behaviours divided into six categories (feeding, movement, social, resting, comfort, stretching) were scored. In addition, the tonic immobility test was performed, and the plumage status and footpad dermatitis of the birds were assessed. The results revealed a significant influence of the housing system on the behaviour, plumage status, and foot health of laying hens. While the housing system affected all behaviours, mainly feeding and comfort behaviours were influenced by the genotype of the hens and the interaction between the housing system and genotype. All genotypes displayed a similar behavioural pattern within the two housing systems, except for the commercial hybrid, which differed in its behaviour from the others adapting better to the enriched cage environment. In particular, the free-range system provided hens with more opportunities to engage in movement and comfort behaviour, and social interactions. Furthermore, hens in the free-range system exhibited better plumage conditions and lower rates of footpad dermatitis, indicating a positive impact on their overall welfare.

Comparison of Fatty Acid Profile in Egg Yolk from Late-Age Hens Housed in Enriched Cages and in a Free Range System.

In recent years, the free-range system for laying hens has increased, driven by societal sensitivity to animal welfare. This study aimed to comparatively analyze the total lipid, cholesterol, and fatty acid composition of egg yolks of late-age laying hens reared in enriched cages (C) and the free-range system (FR). Eggs were collected from Lohmann Brown Classic hens at the 68th, 70th, 72nd, and 74th week of age. The concentrations of total lipids and cholesterol were not affected (p > 0.05) by either factor. Egg yolk from the FR group showed lower (p < 0.01) monounsaturated fatty acids and higher (p < 0.01) polyunsaturated fatty acid (PUFA) compared with that of the C group. From a nutritional point of view, the PUFA n-6/n-3 and the PUFA/SFA ratios of egg yolk from the FR group were favorably lower and higher (p < 0.01) compared with the C one. Conversely, hen age did not affect (p > 0.05) the fatty acid composition of yolks. Interactions between factors were found for total n-3 and n-6 PUFA and the n-6/n-3 ratio (p < 0.01), as well as the thrombogenic index (p < 0.05). In conclusion, the results confirmed that the free-range system may improve the nutritional yolk fatty acid profile and its positive impact on human health.

Exploring the similarities between risk factors triggering depression in humans and elevated in-cage "inactive but awake" behavior in laboratory mice.

Depression is a human mental disorder that can also be inferred in non-human animals. This study explored whether time spent inactive but awake ("IBA") in the home-cage in mice was further triggered by risk factors similar to those increasing vulnerability to depression in humans (early life stress, genetic predispositions, adulthood stress). Eighteen DBA/2 J and 18 C57BL/6 J females were tested, of which half underwent as pups a daily maternal separation on post-natal days 2-14 (early-life stress "ELS") (other half left undisturbed). To assess the effect of the procedure, the time the dams from which the 18 subjects were born spent active in the nest (proxy for maternal behavior) was recorded on post-natal days 2, 6, 10 and 14 for 1 h before separation and following reunion (matched times for controls), using live instantaneous scan sampling (total: 96 scans/dam). For each ELS condition, about half of the pups were housed post-weaning (i.e., from 27 days old on average) in either barren (triggering IBA and depression-like symptoms) or larger, highly enriched cages (n = 4-5 per group). Time mice spent IBA post-weaning was observed blind to ELS treatment using live instantaneous scan sampling in two daily 90-min blocks, two days/week, for 6 weeks (total: 192 scans/mouse). Data were analyzed in R using generalized linear mixed models. The dams were significantly more active in the nest over time (p = 0.016), however with no significant difference between strains (p = 0.18), ELS conditions (p = 0.20) and before/after separation (p = 0.83). As predicted, post-weaning barren cages triggered significantly more time spent IBA in mice than enriched cages (p < 0.0001). However, neither ELS (p = 0.4) nor strain (p = 0.84) significantly influenced time mice spent IBA, with no significant interaction with environmental condition (ELS × environment: p = 0.2861; strain × environment: p = 0.5713). Our results therefore only partly support the hypothesis that greater time spent IBA in mice is triggered by risk factors for human depression. We discuss possible explanations for this and further research directions.

Feed form and perch design do not interact to production performance, gastrointestinal tract traits, behaviour and welfare of laying hens reared in enriched cages

ABSTRACT 1. It was hypothesised that perch material and design may affect utility and maintenance energy demand in laying hens, affecting their feed form preferences and daily feed consumption. Accordingly, perch design and feed form on hen performance, gastrointestinal tract functions and some behavioural and welfare-related traits were studied in laying hens (ATAK-S) reared in enriched colony cages from 24 to 40 weeks of age. 2. The experiment was a 2 × 2 factorial investigating two perch materials and design (circular steel or mushroom-shaped plastic) and feed form (mash or crumble). A total of 396 hens were randomly assigned to one of the four treatment groups with nine replicates each (11 birds per replicate). 3. Except for feeding behaviour and prevalence of foot pad dermatitis at 40 weeks of age, the modification of the perch design did not have a significant effect on the traits examined. Mushroom-shaped plastic perches reduced feeding behaviour (p < 0.01) and the incidence of foot pad dermatitis at 40 weeks of age (p < 0.001). 4. Performance traits were not affected by feed form. Intake, final body weight and FCR for crumble-fed laying hens were greater than those fed mash (p < 0.01). 5. Hens fed mash had higher (p < 0.01) relative gizzard weights along with lower (p < 0.05) pH values, pancreatic chymotrypsin, amylase and lipase activities (p < 0.05), and duodenal absorption surface areas (p < 0.01). Ultimately, this gave higher protein digestibility (p < 0.05) compared to those receiving crumble. 6. In conclusion, in enriched cage rearing systems, mashed feed was preferred over crumble to efficiently maintain productive performance. Compared to circular steel, plastic mushroom-shaped perches were associated with better footpad health and welfare.

Influence of organic and cage housing system on egg quality in laying hens

Abstract Most of the eggs for consumption are produced in a conventional housing system although the demand for organic eggs is increasing because consumers assume better nutritional characteristics. This study was conducted to compare the quality of organic eggs and enriched cage eggs. A total of 409 organic eggs and 385 eggs from hens housed in enriched cages were directly collected from 15 different farms, located in Spain and were analyzed within 4 days after laying. The differences in quality by removing the time bias that can be caused by marketing time were thus determined. All the hens were of three different lines, 47–50 weeks old and consumed commercial feed with the same nutritional composition. The quality traits evaluated were egg weight (EW g), egg shape index (SI), shell thickness (ST), shell percentage (SP), Haugh units (HU), dense albumen percentage (DAP), total albumen percentage (TAP), yolk color (YC), yolk percentage (YP), Roche scale (RS), moisture (M), ash content (AC), total protein (TP), total yolk carotenoids (TYC), total fat (TF), saturated fatty acids (SFA), monounsaturated fatty acids (MFA), and polyunsaturated fatty acids (PFA). Estimates of differences were obtained by generalized least squares using housing system, genetic line and their interaction as factors. Significant differences were observed for EW (65.3 vs 62.9), SI (77.60 vs 76.10), HU (83.60 vs 81.80), TAP (66.5 vs 64.17), YC (3.11 vs 1.89), RS (11.79 vs 9.48), TP (9.99 vs 8.55), TYC (4.188 vs 2.650), SFA (32.20 vs 30.00) and MFA (53.40 vs 44.20) in favor of the enriched cage system. In the organic system, the quality parameters that had higher and significant values were ST (0.34 vs 0.32), SP (10.52 vs 9.41), YP (25.20 vs 24.30), AC (1.12 vs 0.93) and PFA (26.00 vs 14.00). Significant interactions between the housing system and the hen line followed the same pattern observed for fixed effects. Organic eggs were lighter, less rounded with better shell quality and therefore showed lower Haugh unit values and a lower albumen percentage. Total protein, total fat, and lipid profile were within the usual average values for commercial eggs, although the proportion of polyunsaturated fatty acids, which are beneficial for consumers, was higher in organic eggs.

Comparative impact of bacitracin and select feed additives in the feeding program of Lohmann LSL-Lite pullets at the onset of lay through to 31 weeks of age

Abstract There are limited investigations on the role of feed additives in easing transition of pullets to egg production phase. We investigated the effects of supplementation of bacitracin methylene disalicylate (BMD) and select feed additives (myristic acid [MA], benzoic acid [BA], and Aspergillus niger probiotic [PRO]) in feeding program for pullets from the onset of lay through to 31 weeks of age (woa). Parameters measured included hen-day egg production (HDEP), feed intake (FI), feed conversion ratio (FCR), egg quality characteristics, ceca microbial activity, apparent retention of components, and plasma metabolites. A total of 1,200 Lohmann LSL Lite pullets were procured at 18 woa and placed in enriched cages (30 birds/cage) based on body weight (BW) and allocated to five diets. The diets were a basal diet formulated to meet specifications or basal mixed with either BMD, MA, BA, or PRO. Birds had free access to feed and water throughout the experiment. Between 18 and 20 woa, birds fed BMD ate a similar (P &amp;gt; 0.05) amount of feed to BA birds, but more (P = 0.0003) than birds fed basal, MA, or PRO diets. Basal birds had lower HDEP (P = 0.001) and lighter eggs (P &amp;lt; 0.0001) than birds fed any of the feed additives between 21 and 31 woa. The basal hens had a higher (P = 0.009) abundance of Escherichia coli than birds fed BMD, BA, and PRO diets. Consequently, BMD, BA, and PRO birds had a higher (P = 0.011) Lactobacilli: E. coli ratio (LER) than hens fed the basal diet. Specifically, relative to basal-fed hens, the LER of the BMD, MA, BA, and PRO hens was higher by 37%, 21%, 26%, and 45%, respectively. Moreover, birds fed PRO tended to have a higher concentration of ceca digesta acetic acid (P = 0.072) and a lower concentration of isobutyric acid (P = 0.096). In conclusion, supplementing pullet diets with broad-spectrum antibiotics or feed additives (MA, BA, and PRO) had a positive impact on FI, and egg production linked to modulation of indices of gut health. The results suggested supplementing feed additives in feeding programs for pullets at the onset of lay can bolster productivity outcomes.

Grid cells in rats deprived of geometric experience during development

The medial entorhinal cortex (MEC) is part of the brain's network for dynamic representation of location. The most abundant class of neurons in this circuit is the grid cell, characterized by its periodic, hexagonally patterned firing fields. While in developing animals some MEC cell types express adult-like firing patterns already on the first exposure to an open spatial environment, only days after eye opening, grid cells mature more slowly, over a 1-to-2-wk period after the animals leave their nest. Whether the later emergence of a periodic grid pattern reflects a need for experience with spatial environments has not been determined. We here show that grid-like firing patterns continue to appear during exploration of open square environments in rats that are raised for the first months of their life in opaque spherical environments, in the absence of stable reference boundaries to guide spatial orientation. While strictly periodic firing fields were initially absent in these animals, clear grid patterns developed after only a few trials of training. In rats that were tested in the same open environment but raised for the first months of life in opaque cubes, with sharp vertical boundaries, grid-like firing was from the beginning indistinguishable from that of nondeprived control animals growing up in large enriched cages. Thus, although a minimum of experience with peripheral geometric boundaries is required for expression of regular grid patterns in a new environment, the effect of restricted spatial experience is overcome with short training, consistent with a preconfigured experience-independent basis for the grid pattern.

Structural enrichment for laboratory mice: exploring the effects of novelty and complexity.

Providing structural enrichment is a widespread refinement method for laboratory rodents and other animals in captivity. So far, animal welfare research has mostly focused on the effect of increased complexity either by accumulating or combining different enrichment items. However, increasing complexity is not the only possibility to refine housing conditions. Another refinement option is to increase novelty by regularly exchanging known enrichment items with new ones. In the present study, we used pair-housed non-breeding female C57BL/6J and DBA/2N mice to investigate the effect of novelty when applying structural enrichment. We used a double cage system, in which one cage served as home cage and the other as extra cage. While the home cage was furnished in the same way for all mice, in the extra cage we either provided only space with no additional enrichment items (space), a fixed set of enrichment items (complexity), or a changing set of enrichment items (novelty). Over 5 weeks, we assessed spontaneous behaviors, body weight, and extra cage usage as indicators of welfare and preference. Our main results showed that mice with access to structurally enriched extra cages (complexity and novelty) spent more time in their extra cages and complexity mice had lower latencies to enter their extra cages than mice with access to the extra cages without any structural enrichment (space). This indicates that the mice preferred the structurally enriched extra cages over the structurally non-enriched space cages. We found only one statistically significant difference between the novelty and complexity condition: during week 3, novelty mice spent more time in their extra cages than complexity mice. Although we did not detect any other significant differences between the novelty and complexity condition in the present study, more research is required to further explore the potential benefits of novelty beyond complexity.

Role of housing system and season on the carcass and meat quality traits of growing rabbits reared in Italian commercial farms

The aim of this study was to compare the carcass traits and meat quality of growing rabbits reared in four types of commercially available housing systems (i.e. bicellular cages, dual-purpose cages, enriched cages and elevated pens) across three production cycles covering different seasons (i.e. autumn, winter and summer) under field conditions. The rabbits originated from 12 commercial farms (three farms per housing system) located in the Northeast of Italy and were slaughtered in five commercial slaughterhouses at a slaughter age from 71 to 90 d. Twenty carcasses per farm and cycle were randomly selected at the slaughterhouse and carcass and meat quality traits were evaluated 24 h post-mortem. The heaviest carcass weights were found in rabbits reared in enriched cages, followed by those in parks, while the lightest carcasses were found in rabbits from bicellular cages. Carcass fat and longissimus lumborum proportions were higher and hind legs proportion lower in carcasses of rabbits kept in enriched cages compared to those from the other systems. Based on significant differences for meat quality traits (i.e. pH, L*, thawing losses and shear force) among housing systems, ante-mortem stress was likely lower in rabbits from enriched cages and parks than in those from bicellular and dual-purpose cages. Nevertheless, these differences were not translated into noticeable changes in meat quality because of the small variations among housing systems. Overall, the observed differences could not be strictly and exclusively related to the enclosure in which the animals were housed, but also to other production and ante-mortem factors. The rearing season significantly affected slaughter traits, with lower slaughter and carcass weights in summer compared to winter and autumn. Despite the limit in the sample size of investigated farms, this study highlighted that under field conditions the final product quality of rabbits is not clearly distinguishable based on the housing system per se.

Egg production, egg quality, and fatty acids profiles in eggs and tissues in Lohmann LSL lite hens fed algal oils rich in docosahexaenoic acid (DHA)

Enriching eggs with omega-3 fatty acids (n-3 FA), such as docosahexaenoic acid (DHA), is a well-accepted practice that benefits the egg industry and consumers. However, issues around cost, sustainability, and product acceptance have necessitated the search for alternatives to feeding hens fish oil for DHA enrichment. The effects of feeding 2 algal oils on egg production and DHA enrichment in eggs and selected tissues were investigated. The algal oils were: 1) OmegaPro (OPAO) standardized algal oil for DHA content and 2) Crude algal oil (CAO). A total of 400, 46-wk-old Lohmann LSL lite hens were housed in enriched cages (10 birds/cage) and allocated 5 diets (n=8) for a 12-wk trial. The iso-caloric and -nitrogenous diets were a standard corn and soybean meal diet, standard plus 0.25 or 0.76% OPAO and standard plus 0.23 or 0.69% CAO; algal oils diets supplied similar DHA at each level. Egg production indices (hen day egg production, feed intake, FCR, egg weight, egg mass, and eggshell quality) were monitored for 10 wk. Diet samples were analyzed for fatty acids (FA) on wk 1, 6, and 12 and eggs on wk 4, 5, 6, 9, and 12. At the end of the trial, one hen/cage was weighed and dissected for liver, breast and thigh for FA and long bones for ash content analyses. Concentration of omega-6 to omega-3 FA ratio was 12.9, 6.64, 3.48, 6.96, and 3.59 for standard, 0.23 and 0.76% OPAO, 0.25 and 0.69% CAO, respectively. Algal oils increased (P ≤ 0.046) eggshell thickness linearly. The concentration of DHA in the eggs from the birds fed the standard, 0.23 and 0.76% OPAO, 0.25 and 0.69% CAO was 84, 195, 286, 183, and 297 mg/100g egg, respectively, and algal oils enriched eggs with DHA linearly and quadratically (P ≤ 0.01). In conclusion, algal oils increased the concentration of DHA in eggs and had no adverse effects on egg production and eggshell quality.

Intraspecific Interactions Decrease Stress Affecting Welfare in Shelter Dogs: A Comparison of Four Different Housing Conditions.

Shelters are stressful environments for domestic dogs (Canis familiaris). Evaluating dogs' welfare is crucial to improve their life condition and to promote a better management of shelters. We aimed at verifying which variables improved welfare in 10 shelter dogs ((hosted in the shelter "Centro cinofilo Caerite" in Bracciano (Rome)) by analysing their behavioural responses in different environmental conditions. Furthermore, faecal samples were taken to measure cortisol metabolites (CM), a non-invasive method to evaluate adrenocortical activity in dogs. Dogs were observed for a total of 400 h in 4 different cage conditions: (i) alone in a cage; ii) alone in an enriched cage; (iii) in cage with conspecifics; (iv) in cage with regular interaction with humans outside the cage. Alone in the cage situation showed highest frequencies of displacement activities (Friedman test: χ2 = 13.32; p = 0.004). In contrast, being in the cage with conspecifics seems to reduce displacement activity frequency, as well as the level of faecal cortisol metabolites (Friedman test: χ2 = 8.04; p = 0.045). Our results suggest that conspecifics' presence is the best way to reduce stress in shelter dogs. This research could provide some useful guidelines for managing shelters and improving dogs' life condition.

Effects of more natural housing conditions on the muscular and skeletal characteristics of female C57BL/6J mice

BackgroundEnrichment of home cages in laboratory experiments offers clear advantages, but has been criticized in some respects. First, there is a lack of definition, which makes methodological uniformity difficult. Second, there is concern that the enrichment of home cages may increase the variance of results in experiments. Here, the influence of more natural housing conditions on physiological parameters of female C57BL/6J mice was investigated from an animal welfare point of view. For this purpose, the animals were kept in three different housing conditions: conventional cage housing, enriched housing and the semi naturalistic environment. The focus was on musculoskeletal changes after long-term environmental enrichment.ResultsThe housing conditions had a long-term effect on the body weight of the test animals. The more complex and natural the home cage, the heavier the animals. This was associated with increased adipose deposits in the animals. There were no significant changes in muscle and bone characteristics except for single clues (femur diameter, bone resorption marker CTX-1). Additionally, the animals in the semi naturalistic environment (SNE) were found to have the fewest bone anomalies. Housing in the SNE appears to have the least effect on stress hormone concentrations. The lowest oxygen uptake was observed in enriched cage housing.ConclusionsDespite increasing values, observed body weights were in the normal and strain-typical range. Overall, musculoskeletal parameters were slightly improved and age-related effects appear to have been attenuated. The variances in the results were not increased by more natural housing. This confirms the suitability of the applied housing conditions to ensure and increase animal welfare in laboratory experiments.

The Effect of Housing Environment on Physical Egg Quality of White Egg Layers

Currently, the egg industry is experiencing a shift in demand for eggs from cage-free environments. This study aims to evaluate the egg quality parameters of white eggs laid in several different housing environments utilized in the industry. Egg quality parameters from battery cages, barren colony cages, enriched colony cages and cage-free pens were compared. Overall, most egg quality parameters were found to be different across housing environments. Battery cages produced the heaviest eggs and eggs with the highest Haugh unit (p &lt; 0.05). Cage-free hens produced eggs with the darkest yolks, lowest Haugh units, strongest shells and highest solids percentage compared to other environments (p &lt; 0.05). This study did not detect differences between any housing environment in shell color, shell elasticity, vitelline membrane strength or vitelline membrane elasticity (p &gt; 0.05). Moreover, this study did not detect any differences in egg quality parameters between enriched and barren colony cages (p &gt; 0.05). It appears that white egg-laying hens had superior egg quality performance in caged environments and that cage-free pens only improved yolk color. Furthermore, it appears that simply adding enrichments to cages does not affect any egg quality parameters. From the results of our study, we believe that current intensive environments, such as cages, are the most beneficial for white egg layer egg quality and that as the industry moves toward cage-free, new strategies will need to be developed to preserve egg quality. More research is needed, particularly evaluating free-range environments.

Evaluation of Physical Egg Quality Parameters of Commercial Brown Laying Hens Housed in Five Production Systems.

This study evaluates the effect of housing environment on the egg quality characteristics of brown egg layers as many different environments are currently used in the industry. Battery cages, barren colony cages, enriched colony cages, cage-free, and free-range environments were evaluated. Overall, all egg quality measurements were affected by housing environment (p < 0.01) except for vitelline membrane strength, elasticity, and egg solids. Eggshells and yolks were lightest in barren colony cages and darkest from free-range hens (p < 0.0001). Free-range eggs were heavier than eggs from all other environments (p < 0.0001). Cage-free eggs had lower albumen height and Haugh units than other environments (p < 0.0001). Lastly, cage-free and free-range eggs had stronger eggshells than the other environments (p < 0.0001), and free-range eggs had more elastic eggshells than eggs from conventional battery cages and barren colony cages (p < 0.01). Access to the range seemed to give free-range hens different nutritional advantages, which allowed for the darker yolks and shells. Furthermore, eggs from barren colony cages seemed to exhibit more negative characteristics. Simply adding enrichments to colony cages did not improve or detract from egg quality. From this research, it appears that, as the industry moves toward extensive environments, the egg quality of brown egg layers will improve.