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Navigation ability of White and Brown hens in an aviary system during laying phase
No full textIn cage-free systems, perches allow birds to exercise and to use the vertical space, therefore improving animal distribution. However, hen navigation in the complex aviary environment could result in failed landings and collisions, which could be influenced by genotype and aviary design. We tested the hypothesis that increased perch availability could improve the navigation ability of hens of different genotypes during the laying phase. To this scope, we monitored 1,800 hens (from 28 to 39 weeks of age) housed in a multi-tier aviary system and distributed in 8 pens (225 hens/pen) according to a bi-factorial design with two genotypes (Lohmann White vs. Hyline Brown) and two types of pens (enriched or not with additional perches). In the enriched pens, 6 additional perches (1.20 m long), were placed at the outer net walls and at different heights (0.30, 0.90, and 1.50 m on the left side; 0.60, 1.20 m, and 1.80 m on the right side). Hen movements were video-recorded at 28, 32, 36, and 39 weeks of age, and the number and rate of successful landings on the ground and take-offs to the aviary were scored every 10 min/hour (9:00 to 21:00). Observations were categorized into four periods throughout the day: early hours (5:00 to 08:00), morning (9:00 to 12:00), afternoon (13:00 to 16:00), and evening (17:00 to 21:00). Landings decreased from 28 and 32 weeks to 36 and 39 weeks of age (88 to 78 events per observation hour; P<0.05). The rate of successful landings did not change with age (96.0%, on average), being the highest at early day hours compared with the other periods (99.4% vs. 94.7%; P<0.001). White hens showed a 2.5-fold number of landings per observation hour (119 vs. 48; P<0.001) with a higher successful rate (+2%; P<0.001) compared with brown hens, whereas the presence of additional perches affected neither the number of landings nor their successful rate. Take-offs number (56 events per observation hour, on average) and their successful rate (99.8%, on average) did not change with age. The number of take-off was 3.3-fold in White compared to Brown hens (87 vs. 26 events per observation hour; P<0.001) and 9.3% higher in the pens with additional perches compared to pens without (P<0.05), whereas their successful rate was similar among groups. In conclusion, the navigation ability of hens during the laying period was more influenced by genotype and period of the day rather than by hen age or the presence of additional perches in the aviary
Risk factors for navigation ability of laying hens at housing in an aviary system
No full textTo evaluate the risk factors for navigation ability of two genotypes of laying hens at housing in an aviary system, 1,800 pullets, half Lohmann White-LSL and half Hy-line Brown, were randomly allocated at 17 weeks of age in 8 pens of an experimental aviary (3 tiers), according to a bi-factorial arrangement, 2 genotypes (brown vs. white hens) × 2 types of pens (enriched or not enriched with additional perches). Data collected by video-recording at 17 and 20 weeks of age were used to assess the number of successful and unsuccessful landings from any part/equipment of the aviary to the floor. Risk factors related to failed landings were evaluated by multivariate logistic regression analysis through a forward stepwise selection using the PROC LOGISTIC of SAS. The regression coefficients were expressed as odds ratio (OR) with 95% confidence interval (CI). Compared to brown hens, white hens performed a significantly higher number of landings per hour in the observation interval (80.7 vs. 35.4; P<0.001) with a higher success rate (94.8% vs. 88.6%; P<001). Brown hens had higher odds of failed landings compared with white hens (OR: 6.65; 95% CI: 4.36-10.1). The logistic regression analysis showed significantly higher odds (OR: 1.90; P<0.001) of experiencing failed landings at 17 weeks compared to 20 weeks. No significant difference in the number or in the rate of success of landings was recorded between enriched and not enriched pens, where the logistic regression analysis only measured a trend (OR: 1.29; P=0.09). The odds of failed landings were greatly higher when comparing long with medium flight distance to floor (i.e. hens starting from the third vs. the second tiers of the aviary) (OR: 31.1; P<0.001) and lower comparing short (i.e. hens starting from the first tiers of the aviary) with medium flight distance (OR: 0.17; P<0.001). In conclusion, under the condition of the present study, white hens exhibited higher navigation activity and ability compared to brown hens since the first week after housing; the navigation ability improved four after housing weeks; the enrichment with additional perches played a minor role. Long-term effects on space use should be evaluated over the laying period
Welfare of laying hens in a cage free system: effect of genotype and enrichment on animal based measures
Full text linkCage-free systems are known to increase activity and behavioural pattern for laying hens, but effects on overall welfare are controversial depending on several factors. Our study aimed to evaluate welfare of 1,800 laying hens of two genotypes (Hyline Brown vs. Lhomann White) housed in an aviary in 8 pens, enriched or not with additional perches. Live weight, percentage of keel bone and foot lesions, and plumage damage and cleanliness were assessed six times from 25 to 39 weeks of age on a sample of 400 hens (50/pen). No differences between hens were observed until 32 weeks. Then, at 39 weeks, the occurrence of keel bone lesions was higher and that of foot lesions lower in Brown compared to White hens (P<0.01). At all recordings, plumage cleanliness was better in Brown than in White hens (P<0.001), whereas the plumage damage was low (1% of hens) and not different among experimental groups. At 39 weeks, the occurrence of foot lesions was higher in pens enriched with additional perches than not enriched pens (P<0.05). In conclusion, lesions associated with welfare concerns appeared when the age of hens increased, and differed between genotypes, whereas the enrichment with additional perches played a minor role
Effect of enrichment with hemp seeds on the behaviour of laying hens in a cage-free system
No full textThe present study evaluated the effect of hempseed supplementation over the diet as an envi-ronmental enrichment on behaviour of laying hens. A 4-weeks trial run with 1800 Hy-line Brown laying hens, from 37 to 40 weeks of age, randomly allocated in 8 pens of an experimental aviary. Whole hempseeds were distributed (10% of the daily feed intake) in additional manual feeders in two pens or directly on the litter in other two pens, once a day at the same hour (10:00 a.m.), whereas no enrichment was provided in the other 4 pens. Hen behaviour was assessed through the analysis of 4 days of video recordings (one day per week) by scanning 10 sec every 30 min for every hour to score the number of hens on the floor, pecking the feeder, pecking the litter, moving, preening, dust-bathing, aggression, piling, inactive. Data were submitted to ANOVA with hemp seeds enrichment and hour of observation as main effects and the pen as a random effect, using the PROC GLIMMIX of SAS. The enrichment with hemp seeds in the feeder was obviously associated to a rate of animals pecking the feeder (7.37% of observed hens), which corresponded to a decreased preening in the same pens compared to those that received hemp seeds on the litter or did not receive any enrichment (11.5% vs. 15.3% and 19.7% of observed hens, respectively; P<0.001). In the same pens receiving hemp seed in the feeders, a higher rate of piling hens was observed compared to the group with hemp seed distributed on the litter and that without enrichment) (5.58% vs. 4.37% and 2.42% observed hens; P=0.01). Other behaviours were not modified by the environmental enrichment. As for changes according to the hour of observation, the highest number of hens on the ground was observed around 9:00 a.m. (43.8% of observed hens), when people entered the farm for daily recordings, ranging from 24.3% to 41.7% at the other observation hours. The rate of hens pecking the ground increased after switching on the lights and remained high until 8:00 a.m. when it started to decrease; then, it increased again from 11:00 a.m. until the end of daylight, which was negatively associated to the rate of inactive animals. Dust bathing showed a peak between 11 a.m. and 12:00 a.m., whereas preening was especially observed at the same hours besides 2 hours after switching on the light. In conclusion, the enrichment with hemp seeds did not substantially change the behaviours of animal, except for the opportunities of feeding alternative to the commercial diets. It should be further proved that the higher rate of piling hens in pens receiving hemp seeds, especially at the time of the entrance of people in the farm, could be considered an anticipatory behaviour eventually associated to a positive effect of the enrichment on hen affective status
Behaviour of laying hens of two genotypes in a cage-free system enriched with hay bales
Full text linkEnvironmental enrichment can play a positive role in cage-free systems by allowing hens to diversify their behavioural repertoire and reducing aggression among animals. Our study evaluated the effect of the enrichment with hay bales in an aviary system on the behaviour of 1,800 laying hens (Hyline Brown and Lhomann White) from 50 to 53 weeks of age. Behaviours, expressed as the percentage of hens observed on the floor, were scored through a 10-sec scan every 30 min per hour (05:30-20:30) and observations were grouped per day-time interval, i.e. early, midday, afternoon, and evening. Data were submitted to ANOVA with genotype, enrichment, and time interval (not discussed here) as main effects, and pen as a random effect. As for the enrichment, the presence of hay bales increased the number of hens on the floor and the rate of those interacting with the enrichment at the expenses of hens performing dustbathing, sitting, or walking. As for the genotype, a higher number of brown hens was recorded on the floor, with a higher rate of them sitting-inactive and preening compared to white hens which performed more dustbathing, interactions with hay bales, ground-pecking, and piling (P<0.01). In conclusion, hay bales attracted hens and reduced the expression of some comfort behaviours; white hens were more active and showed more risky behaviours such as piling compared to brown hens. Acknowledgements: This study was carried out within Agritech National Research Center and was funded by the European Union – NextGenerationEU (PNRR – Missione 4 Componente 2, Investimento 1.4 – D.D. 1032 17/06/2022, CN00000022), and by Unimpresa, University of Padova (call 2019)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Landings and climbings of pullets in a cage free range system at housing: effect of genotype and enrichment
No full textTo evaluate the adaptability of hens at housing in a cage free system, 1800 pullets (17 weeks of age) were allocated in 8 pens of an aviary according to a tri-factorial arrangement with two genotypes (Hyline brown vs. Lohmann white) and two types of pens (enriched or not with additional perches). At 17 and 20 weeks of age, the number and rate of successful landings at ground and climbings to the aviary were scored (10 min/hour; 9.00 to 21.00). Unsuccessful movements were associated to collisions. The number (218 vs. 67.6) and the success rate (93.3% vs. 83.8%) of landings were higher in white vs. brown hens (P<0.001) and increased from 17 to 20 weeks (89.8 to 196, P<0.001; and 85.1% to 92.0%, P<0.01, respectively). Similarly, the number (177 vs. 21.6; P<0.001) and success rate (99.1% vs. 96.5%; P<0.10) of climbings were higher in white than brown hens and increased with age (58.4 to 141, P<0.001; 95.7% to 99.8%, P=0.01). The enrichment with additional perches did not affect landings or climbings. In conclusions, large differences in the movement activity were measured between genotypes, while the adaptation of hens to the aviary increased with age
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