The Effect of Different Feed and Stocking Densities on Growth and Survival Rate of Blue Swimming Crablets (Portunus pelagicus)
Ariyati, R.W. ; Rejeki, S. ; Bosma, R.H. - \ 2018
In: IOP Conference Series: Earth and Environmental Science IOP Conference Series: Earth and Environmental Science 116 (2018)1. - ISSN 1755-1307IOP Publishing (IOP Conference Series: Earth and Environmental Science )
blue swimming - crablet - Feed - stocking density
Blue swimming crab is targeted by commercial fisheries because of the high economic value, good taste, and attractive colors. As a result, the stock is overexploited and fisherman catch market also juveniles. The most sustainable solution would be to stop fishing for commercial trade and to culture this crab from brood to market size. This study aimed to find the best feed and stocking density for the on-growing of crablets. In 20 tanks juvenile crabs with a carapace width±1 cm were stocked in three densities; 40, 60 and 80 crablets / m2, and fed ad-libitum twice a day with either trash fish or pellets of shrimp feed, for 8 weeks. The circular ( 1.6 m x 1 m) tanks with 1 m3 of water were aerated, and temperature, salinity, dissolved oxygen and pH recorded daily. In the end, growth and survival rates were determined. In general, feeding the crablets at a density of 40 m-2 gave the highest growth. For crablest fed with pellets, the density of 40 m-2 gave significantly better growth than 80 m-2. The crablets at a density 40 m-2 having a fish diet with the density 40 m-2 grew better than 60 and 80 m-2. There was no significant difference between fed used among different densities. The lower densities resulted in higher survival, either on crablets fed with pellets or fish. But, crablets fed the fish diet and cultured in the lowest density (40 m-2) had the highest survival rate.
|The Effect of Different Feed and Stocking Densities on Growth and Survival Rate of Blue Swimming Crablets (Portunus pelagicus)
Ariyati, Restiana W. ; Rejeki, Sri ; Bosma, R.H. - \ 2017
feed - stocking density - blue swimming - crablet
Broiler chicken stocking density affects use of environmental enrichment objects
Jong, I.C. de; Goertz, M. - \ 2017
In: Xth European Symposium on Poultry Welfare. - - 2 p.
broilers - Environmental enrichment - behaviour - stocking density - broilers - environmental enrichment - behaviour - stocking density
Ontwikkelen beweidingsystemen bij hoge veebezetting op kleine huiskavel : beweidingsonderzoek op klei- en veengrond in 2015
Galama, P.J. ; Holshof, G. ; Reenen, K. van - \ 2017
Wageningen : Wageningen Livestock Research (Wageningen Livestock Research rapport 1016) - 51
melkvee - beweidingssystemen - zware kleigronden - veengronden - bezettingsdichtheid - melkveehouderij - nederland - dairy cattle - grazing systems - clay soils - peat soils - stocking density - dairy farming - netherlands
McGraze : Concept model for modern continuous stocking
Klein Koerkamp, Pim ; Li, Peiyun ; Oostdam, Marieke ; El-Din Sherif, Mohie ; Stienezen, M.W.J. ; Philipsen, A.P. - \ 2015
Wageningen UR Livestock Research - 31
dairy farms - grasslands - grazing - pastures - weather - management - stocking density - tools - dairy farming - melkveebedrijven - graslanden - begrazing - weiden - weer - bedrijfsvoering - bezettingsdichtheid - gereedschappen - melkveehouderij
This report analysed the modern continuous stocking system for dairy farms in the Netherlands. This system has to deal with a minimum grass height of 8 or 10cm (depending on the season) in order to obtain maximum grass production. A model should predict the available herbage mass under changing weather conditions and therefore the available fresh grass and the related amount of additional feed needed for the cows. A concept model, called McGraze, is developed for farmers in order to manage modern continuous stocking (Figure 1). McGraze consists of a grass production section and a stoking related section. The grass production section is based on an existing grass production model called LINGRA, which resulted from a literature review to be the most accurate model to predict grass production. LINGRA needs some minor changes in order to fit into McGraze. The stocking related section is key to the final hours of stocking and the related additional feeding, which are the outputs of McGraze. All values used to predict the outputs are a result of a literature study on grass height, grass quality, grass intake and the effect of stocking on grass growth.
Steroids accumulation in recirculating aquaculture systems
Mota, V.C. - \ 2015
Wageningen University. Promotor(en): Johan Verreth, co-promotor(en): A.V.M. Cana´rio; C.I.M. Martins. - Wageningen : Wageningen University - ISBN 9789462575554 - 145
steroïden - recirculatie aquacultuur systemen - prestatieniveau - bezettingsdichtheid - stress - ph - hydrocortison - testosteron - chemische communicatie - visteelt - viskwekerijen - steroids - recirculating aquaculture systems - performance - stocking density - stress - ph - hydrocortisone - testosterone - chemical communication - fish culture - fish farms
Housing and management factors associated with indicators of dairy cattle welfare
Vries, M. de; Bokkers, E.A.M. ; Reenen, C.G. van; Engel, B. ; Schaik, G. van; Dijkstra, T. ; Boer, I.J.M. de - \ 2015
Preventive Veterinary Medicine 118 (2015)1. - ISSN 0167-5877 - p. 80 - 92.
risk-factors - farming systems - lameness prevalence - stall cleanliness - stocking density - cubicle systems - social-behavior - animal-welfare - claw disorders - herd-level
Knowledge of potential synergies and trade-offs between housing and management factors for different aspects of animal welfare is essential for farmers who aim to improve the level of welfare in their herds. The aim of this research was to identify and compare housing and management factors associated with prevalence of lameness, prevalence of lesions or swellings, prevalence of dirty hindquarters, and frequency of displacements (social behavior) in dairy herds in free-stall housing. Seven observers collected data regarding housing and management characteristics of 179 Dutch dairy herds (herd size: 22–211 cows) in free-stall housing during winter. Lame cows, cows with lesions or swellings, and cows with dirty hindquarters were counted and occurrence of displacements was recorded during 120 min of observation. For each of the four welfare indicators, housing and management factors associated with the welfare indicator were selected in a succession of logistic or log-linear regression analyses. Prevalence of lameness was associated with surface of the lying area, summer pasturing, herd biosecurity status, and far-off and close-up dry cow groups (P <0.05). Prevalence of lesions or swellings was associated with surface of the lying area, summer pasturing, light intensity in the barn, and days in milk when the maximum amount of concentrates was fed (P <0.05). Prevalence of dirty hindquarters was associated with surface of the lying area, proportion of stalls with fecal contamination, head lunge impediments in stalls, and number of roughage types (P <0.05). Average frequency of displacements was associated with the time of introducing heifers in the lactating group, the use of cow brushes, continuous availability of roughage, floor scraping frequency, herd size, and the proportion cows to stalls (P <0.05). Prevalences of lameness and of lesions or swellings were lower in herds with soft mats or mattresses (odd ratio (OR) = 0.66 and 0.58, confidence interval (CI) = 0.48–0.91 and 0.39–0.85) or deep bedding (OR = 0.48 and 0.48, CI = 0.32–0.71 and 0.30–0.77) in stalls, compared with concrete, and in herds with summer pasturing (OR = 0.68 and 0.41, CI = 0.51–0.90 and 0.27–0.61), compared with zero-grazing. Deep bedding in stalls was negatively associated with prevalence of dirty hindquarters (OR = 0.50, CI = 0.29–0.86), compared with hard mats. It was concluded that some aspects of housing and management are common protective factors for prevalence of lameness, lesions or swellings, and dirty hindquarters, but not for frequency of displacements.
The influence of floor type before and after 10 weeks of age on osteochondrosis in growing gilts
Koning, D.B. de; Grevenhof, E.M. van; Laurenssen, B.F.A. ; Weeren, P.R. van; Hazeleger, W. ; Kemp, B. - \ 2014
Journal of Animal Science 92 (2014)8. - ISSN 0021-8812 - p. 3338 - 3347.
different coping characteristics - leg weakness - finishing pigs - growth-rate - genetic-parameters - epiphyseal growth - production traits - stocking density - claw disorders - behavior
Osteochondrosis (OC) is a degenerative joint condition developing in a short time frame in young growing gilts that may cause lameness at an older age, affecting welfare and leading to premature culling of breeding sows. Causes of OC are multifactorial including both genetic and environmental factors. Floor type has been suggested to affect OC prevalence and effects might be age dependent during the rearing period. The aim of this study was to investigate possible age-dependent effects of floor type, conventional concrete partially slatted versus wood shavings as deep bedding, on OC prevalence in gilts (Dutch Large White × Dutch Landrace) at slaughter (24 wk of age; 106.5 [14.7 SD] kg of BW). At weaning (4 wk of age; 6.9 [1.3 SD] kg of BW), 212 gilts were subjected to 1 of 4 flooring regimens. Gilts were either subjected to a conventional floor from weaning until slaughter (CC), wood shavings as bedding from weaning until slaughter (WW), a conventional floor from weaning until 10 wk of age after which gilts were switched to wood shavings as bedding (CW), or wood shavings as bedding from weaning until 10 wk of age after which gilts were switched to a conventional floor (WC). After slaughter the elbow, hock, and knee joints were macroscopically examined for OC and scored on a 5 point scale where 0 indicates no OC and 4 indicates the severest form of OC. There was no significant difference (P > 0.4) between treatments on the overall OC prevalence for any joint assessed or at the animal level (all joints combined). At the animal level, however, gilts had greater odds to have OC scores 3 and 4 in the CW treatment (odds ratios [OR] = 2.3; P = 0.05), WC treatment (OR = 2.6; P = 0.02), and WW treatment (OR = 3.7; P <0.001) compared with gilts in the CC treatment. The results indicate that there are no age-dependent effects of floor types on overall OC prevalence. However, wood shavings as bedding seems to increase the odds for severe OC and might affect animal welfare in the long term.
Predicting feather damage in laying hens during the laying period. Is it the past or is it the present?
Haas, E.N. de; Bolhuis, J.E. ; Jong, I.C. de; Kemp, B. ; Janczak, A.M. ; Rodenburg, T.B. - \ 2014
Applied Animal Behaviour Science 160 (2014). - ISSN 0168-1591 - p. 75 - 85.
domestic chicks - alternative systems - tonic immobility - stocking density - eating behavior - genetic lines - flock size - open-field - pecking - fear
Feather damage due to severe feather pecking (SFP) in laying hens is most severe during the laying period. However, SFP can develop at an early age and is influenced by early rearing conditions. In this study we assessed the risk factors during the rearing and laying period for feather damage at 40 weeks of age, in ISA brown and Dekalb White laying hens. Variables related to housing conditions during the rearing and laying period, and variables related to fearfulness (response to novel object, stationary person, and social isolation) and feather pecking (SFP, feather damage and feather eating) were tested to affect feather damage at 40 weeks of age. Feather damage on the neck, back and belly region was assessed on 50 hens, resulting in a total body score, and averaged per flock (based on Welfare Quality ®, 2009). First, analysis was conducted by a two-way ANOVA to assess separate factors to influence feather damage at 40 weeks of age. Hereafter, the final GLM for predicting feather damage at 40 weeks of age included only variables which had P <0.1 in the two-way ANOVA. Risk factors during the rearing period were high levels of SFP at five weeks of age and elevated fear of humans (explained variance 29% and 5.3%, resp.). Risk factors during the laying period were a large group size (explained variance: 1%), distance to stationary person (explained variance: 16%), floor housing compared to aviary housing (1.27 ± 0.18 vs. 0.75 ± 0.07, explained variance: 21%) and a standard management compared to adjusted management such as a radio, pecking blocks, round drinkers and/or roosters (0.98 ± 0.31 vs. 0.51 ± 0.04, explained variance: 26%). Approximately 49% of the laying flocks and 60% of the rearing flocks in this study showed high SFP or severe feather damage. This high incidence emphasizes the severity of the problem and the importance of finding a solution. The results of this study may aid in providing practical solutions to this serious animal welfare problem.
The prevention and control of feather pecking: application to commercial systems
Nicol, C.J. ; Bestman, M. ; Gilani, A.M. ; Haas, E.N. de; Jong, I.C. de; Lampton, S. ; Wagenaar, J.P. ; Weeks, C.A. ; Rodenburg, T.B. - \ 2013
Worlds Poultry Science Journal 69 (2013)4. - ISSN 0043-9339 - p. 775 - 788.
housed laying hens - gallus-gallus-domesticus - housing systems - risk-factors - alternative systems - stocking density - flock size - furnished cages - light-intensity - rearing factors
Studies on the prevalence of feather pecking in different commercial laying hen 23 systems and its welfare and economic impacts are reviewed in the following paper. 24 Current methods for controlling feather pecking include beak-trimming and alterations to light regimes, but these methods have significant disadvantages from the perspective of bird welfare. A substantial body of research has now identified risk factors for feather pecking during both the rearing and laying periods. It is argued that these findings can be translated into optimised management practices that can prevent and control feather pecking whilst simultaneously conferring welfare benefits. The genetic basis of feather pecking is considered, and studies that suggest group selection techniques could produce birds with a reduced tendency to feather peck in commercial flocks are highlighted. Keywords: laying hen; feather pecking; beak-trimming; light; risk factor; genetic selection
Potential risk factors associated with contact dermatitis, lameness, negative emotional state, and fear of humans in broiler chicken flocks
Bassler, A. ; Arnould, C. ; Butterworth, A. ; Colin, L. ; Jong, I.C. de; Ferrante, V. ; Ferrari, P. ; Haslam, S.A. ; Wemelsfelder, F. ; Blokhuis, H.J. - \ 2013
Poultry Science 92 (2013)11. - ISSN 0032-5791 - p. 2811 - 2826.
qualitative behavioral-assessment - foot-pad dermatitis - environmental enrichment - stocking density - leg weakness - housing conditions - light-intensity - road transport - gallus-gallus - dairy-cattle
The objectives of this study were to 1) identify determinants of poor welfare in commercial broiler chicken flocks by studying the associations between selected resource-based measures (RBM, potential risk factors), such as litter quality and dark period, and animal-based welfare indicators (ABM), such as foot pad dermatitis and lameness, and 2) establish the breadth of effect of a risk factor by determining the range of animal welfare indicators associated with each of the risk factors (i.e., the number of ABM related to a specific RBM). Eighty-nine broiler flocks were inspected in 4 European countries (France, Italy, the United Kingdom, and the Netherlands) in a cross-sectional study. The ABM were contact dermatitis (measured using scores of foot-pad dermatitis and hock burn, respectively), lameness (measured as gait score), fear of humans (measured by the avoidance distance test and the touch test), and negative emotional state (measured using qualitative behavior assessment, QBA). In a first step, risk factors were identified by building a multiple linear regression model for each ABM. Litter quality was identified as a risk factor for contact dermatitis. Length of dark period at 3 wk old (DARK3) was a risk factor for the touch test result. DARK3 and flock age were risk factors for lameness, and the number of different stockmen and DARK3 were risk factors for QBA results. Next, the ABM were grouped according to risk factor and counted. Then, in a second step, associations between the ABM were investigated using common factor analysis. The breadth of a risk factor’s effect was judged by combining the number (count) of ABM related to this factor and the strength of association between these ABM. Flock age and DARK3 appeared to affect several weakly correlated ABM, thus indicating a broad range of effects. Our findings suggest that manipulation of the predominant risk factors identified in this study (DARK3, litter quality, and slaughter age) could generate improvements in the related ABM and thereby enhance the birds’ overall welfare status
Prebiotic effects of arabinoxylan oligosaccharides on juvenile Siberian sturgeon (Acipenser baerii) with emphasis on the modulation of the gut microbiota usning 454 pyrosequencing
Geraylou, Z. ; Souffreau, C. ; Rurangwa, E. ; Maes, G.E. ; Spanier, K.I. ; Courtin, C.M. ; Delcour, J.A. ; Buyse, J. ; Ollevier, F. - \ 2013
FEMS microbiology ecology 86 (2013)2. - ISSN 0168-6496 - p. 357 - 371.
salvelinus-alpinus l. - in-vitro fermentation - bacterial fermentation - xylo-oligosaccharides - growth-performance - dietary inclusion - stocking density - amur sturgeon - wheat bran - fish
The potential of a novel class of prebiotics, arabinoxylan oligosaccharides (AXOS), was investigated on growth performance and gut microbiota of juvenile Acipenser baerii. Two independent feeding trials of 10 or 12 weeks were performed with basal diets supplemented with 2% or 4% AXOS-32-0.30 (trial 1) and 2% AXOS-32-0.30 or AXOS-3-0.25 (trial 2), respectively. Growth performance was improved by feeding 2% AXOS-32-0.30 in both trials, although not significantly. Microbial community profiles were determined using 454-pyrosequencing with barcoded primers targeting the V3 region of the 16S rRNA gene. AXOS significantly affected the relative abundance of bacteria at the phylum, family, genus and species level. The consumption of 2% AXOS-32-0.30 increased the relative abundance of Eubacteriaceae, Clostridiaceae, Streptococcaceae and Lactobacillaceae, while the abundance of Bacillaceae was greater in response to 4% AXOS-32-0.30 and 2% AXOS-3-0.25. The abundance of Lactobacillus spp. and Lactococcus lactis was greater after 2% AXOS-32-0.30 intake. Redundancy analysis showed a distinct and significant clustering of the gut microbiota of individuals consuming an AXOS diet. In both trials, concentration of acetate, butyrate and total short-chain fatty acids (SCFAs) increased in fish fed 2% AXOS-32-0.30. Our data demonstrate a shift in the hindgut microbiome of fish consuming different preparation of AXOS, with potential application as prebiotics
Effects of dissolved carbon dioxide on energy metabolism and stress responses in European seabass (Dicentrarchus labrax)
Santos, G.A. ; Schrama, J.W. ; Capelle, J. ; Rombout, J.H.W.M. ; Verreth, J.A.J. - \ 2013
Aquaculture Research 44 (2013)9. - ISSN 1355-557X - p. 1370 - 1382.
salmo-salar l. - graded environmental hypercapnia - acipenser-transmontanus - oxygen-consumption - stocking density - juvenile turbot - white sturgeon - ion regulation - rainbow-trout - water-quality
Elevated carbon dioxide concentrations reduce feed intake and growth in several fish species and induce stress responses. In this study, the effects of moderately elevated CO2 levels on performance, energy partitioning, swimming activity and stress response in European seabass were assessed. European seabass (140.0 g) were reared under two levels of CO2 (1.6 and 7.0 mg L-1) and two feeding levels (FLs) (maintenance and satiation) for 60 days, and fish swimming speed was recorded. At the end of the experiment, fish were subjected to an acute stress test. Blood cortisol, glucose and lactate were analysed. Energy and nitrogen balances were quantified based on measurements of body composition and digestibility coefficients. Moderately elevated chronic CO2 level did neither affect energy requirements for maintenance nor the utilization of digestible energy for growth. However, swimming activity data suggests that FL dependent alterations in energy partitioning took place. Blood cortisol values after the acute stress were affected by additional CO2 exposure and this effect was also dependent on FL. The elevated CO2 exposure of 7.0 mg L-1 appears to act as a chronic stressor as adaptive responses took place, however, this CO2 exposure seems to be still within the allostatic load of the fish.
Footpad dermatitis in Dutch broiler flocks: Prevalence and factors of influence
Jong, I.C. de; Harn, J. van; Gunnink, H. ; Hindle, V.A. ; Lourens, A. - \ 2012
Poultry Science 91 (2012). - ISSN 0032-5791 - p. 1569 - 1574.
pad dermatitis - rearing conditions - carcass injuries - swedish broilers - stocking density - chickens - quality - welfare
In some European countries, footpad dermatitis (FPD) is measured as an indicator of broiler welfare. Prevalence and seasonal variation of FPD was determined within broiler flocks (fast-growing breeds) in the Netherlands. Samples were taken from 386 Dutch flocks at 8 slaughterhouses during a period of one year. Prevalence of footpad dermatitis was related to background information gathered using a food chain certification scheme to identify possible factors of influence. On average, 35.5% of the broilers had no lesions, whereas 26.1% and 38.4% had mild or severe lesions, respectively. Season, age, thinning of flocks, slaughter age, breed, slaughterhouse, and the interaction between thinning and slaughter age significantly affected severity of FPD. Peak flock FPD scores occurred in flocks where 1-d-old chicks were placed in March and December, whereas flocks placed in warm months, between June and August, displayed lower flock FPD scores. Generally, birds sent to slaughter when thinning a flock displayed less severe FPD than birds from completely depopulated flocks. Severity of FPD decreased with age. Because poultry farmer, hatchery, veterinary practice, and feed manufacturer were included in the model as random factors, it was only possible to assess their contribution relative to each other. The broiler farmer had the largest contribution. Also, a large contribution was found for hatchery, perhaps indicating that broiler quality is important. No relationship was observed between FPD and mortality. Across farms, less severe FPD was observed on farms using antibiotics. However, within farms, FPD was more common in flocks where antibiotics had been used compared with flocks that did not require antibiotic treatment. In conclusion, footpad dermatitis was frequently observed in Dutch fast-growing broiler flocks, and many factors had significant effects on severity of FPD, such as breed, thinning of flocks, age at slaughter, slaughter plant, and hatchery.
Space needs of broilers
Bokkers, E.A.M. ; Boer, I.J.M. de; Koene, P. - \ 2011
Animal Welfare 20 (2011)4. - ISSN 0962-7286 - p. 623 - 632.
slow-growing broilers - body-surface area - stocking density - domestic-fowl - laying hens - group-size - chickens - behavior - allowances - welfare
There is continuing debate about the space needs and requirements of broiler chickens, The aims of this study were to measure the amount of floor area a six-week-old broiler occupies for different behaviours and to use the obtained results in two models to estimate the number of birds that can be kept per m2 in large flocks simulating different levels of behavioural synchronisation. Photographs were taken of overhead projections of broilers (2.468 kg on average) kept in floor pens of 1 m2 with either eight (low density) or 16 birds (high density) per pen. Individual body space was measured from these photographs for seven behaviours. Posture and density affected body space of the behaviours idle, drinking, and ground pecking. The first model, computing space needed per bird performing a behaviour in relation to flock size, showed that 15.3-15.7 birds m-2 (37.8-38.7 kg m-2) can be housed maximally, based on low density measurements and 18.5-19.4 birds m-2 (45.7-47.9 kg m-2) based on high density measurements. The second model, computing stocking density based on synchronisation of behaviour and body space, showed that 13.7-15.9 birds m-2 (33.8-39.2 kg m-2) can be housed maximally based on low density measurements and 15.4-18.6 birds m-2 (38.0-45.9 kg m-2) based on high density measurements. Results based on high density measurements implied that birds are compressed. Given the restrictions of a limited number of behaviours and no inclusion of movement and social interactions in the models of this study, stocking density in large flocks should not exceed 16 birds m-2 (39.4 kg) because that would lead to compression of birds which will suppress opportunities for behavioural expression and therefore impair welfare.
Goed effect, maar...
Jong, I.C. de; Gunnink, H. ; Emous, R.A. van; Lourens, A. - \ 2011
De Pluimveehouderij 41 (2011)9. - ISSN 0166-8250 - p. 34 - 35.
pluimveehouderij - vleeskuikenouderdieren - dierenwelzijn - bezettingsgraad - bezettingsdichtheid - diergedrag - huisvesting van kippen - pluimvee - dierlijke productie - diergezondheid - poultry farming - broiler breeders - animal welfare - occupancy rates - stocking density - animal behaviour - chicken housing - poultry - animal production - animal health
Ingrepen overbodig maken door een lagere dierbezetting bij vleeskuikenouderdieren, kan dat? WUR Livestock Research heeft onderzoek verricht. Deel 2: productieperiode.
Klein maar echt effect
Jong, I.C. de; Gunnink, H. ; Emous, R.A. van; Lourens, A. - \ 2011
De Pluimveehouderij 41 (2011)8. - ISSN 0166-8250 - p. 32 - 33.
pluimveehouderij - vleeskuikenouderdieren - bezettingsdichtheid - opfoktechnieken - pluimveehokken - dierenwelzijn - diergedrag - poultry farming - broiler breeders - stocking density - rearing techniques - poultry housing - animal welfare - animal behaviour
Ingrepen overbodig maken door een lagere dierbezetting bij vleeskuikenouderdieren, kan dat? Livestock Reserch deed onderzoek. Deel 1: de opfok.
Effect van bezettingsdichtheid op (de ontwikkeling van) het paargedrag en de technische resultaten bij vleeskuikenouderdieren = Effect of stocking density on (the development of) sexual behaviour and technical performance in broiler breeds
Jong, I.C. de; Lourens, A. ; Gunnink, H. ; Workel, L.D. ; Emous, R.A. van - \ 2011
Wageningen : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 457) - 61
pluimveehouderij - vleeskuikenouderdieren - bezettingsdichtheid - oorzakelijkheid - diergedrag - dierenwelzijn - poultry farming - broiler breeders - stocking density - causality - animal behaviour - animal welfare
This report describes the effects of a reduced stocking density during rearing and/or production on mating behaviour and technical performance in broiler breeders.
Behaviour of domestic fowl in anticipation of positive and negative stimuli
Zimmerman, P.H. ; Buijs, S.A.F. ; Bolhuis, J.E. ; Keeling, L.J. - \ 2011
Animal Behaviour 81 (2011)3. - ISSN 0003-3472 - p. 569 - 577.
different coping characteristics - gallus-gallus-domesticus - laying hens - comfort behavior - animal-welfare - furnished cages - laboratory rats - rattus-norvegicus - stocking density - stress
Underlying the study of animal welfare is the assumption that animals experience emotional states. Although there has been a bias towards studying negative emotions, research into positive emotions is necessary for an overall welfare assessment. The aim of the current study was to find behavioural expressions specific for anticipation of different events in domestic fowl, Gallus gallus omesticus. To this aim, we used a Pavlovian conditioning paradigm by which we induced anticipation of a positive, neutral and negative event. We investigated whether birds were able to discriminate between sound cues signalling these events with different valences and, if so, whether anticipation of different events is reflected in different behavioural responses. The birds showed a response of increased attention to all sound cues. In anticipation of the negative event, the birds showed more head movements and locomotion than in anticipation of both the neutral and positive event, possibly reflecting the aversive nature of the negative event. In anticipation of the positive event, the birds showed more comfort behaviours, such as preening and wing flapping, which have been associated with a state of relaxation. Our study shows that laying hens are able to anticipate differentially a positive, neutral and negative event announced by different sound cues. It is also the first study to identify comfort behaviours as specifically associated with anticipation of a positive event in domestic fowl. Comfort behaviours may therefore be associated with a positive emotional state in domestic fowl.
Effects of carbohydrate source for maintaining a high C:N ratio and fish driven re-suspension on pond ecology and production in periphyton-based freshwater prawn culture systems
Asaduzzaman, M. ; Wahab, M.A. ; Verdegem, M.C.J. ; Adhikary, R.K. ; Rahman, S.M.S. ; Azim, M.E. ; Verreth, J.A.J. - \ 2010
Aquaculture 301 (2010)1-4. - ISSN 0044-8486 - p. 37 - 46.
tilapia oreochromis-niloticus - indian major carps - macrobrachium-rosenbergii - cyprinus-carpio - common carp - extensive aquaculture - artificial substrate - cirrhinus-mrigala - stocking density - fertilizer value
The present research investigated the effect of carbohydrate (CH) source for maintaining a high C:N ratio, and tilapia driven bioturbation on pond ecology, production and economical performances in C/N controlled periphyton-based (C/N-CP) freshwater prawn ponds. Two carbohydrate sources (high-cost tapioca starch and low-cost maize flour) were compared in 40 m2 ponds stocked with 80 freshwater prawn (Macrobrachium rosenbergii) juveniles (individual weight 0.81 ± 0.03 g) and 20 finfish fingerlings (Nile tilapia, Oreochromis niloticus and Indian major carp rohu, Labeo rohita) in three different combinations: 100% tilapia, 50% tilapia + 50% rohu, and 100% rohu (individual weight 27.7 ± 0.6 g). The CH sources for increasing C:N ratio from 10 (as in feed) to 20 had no significant effect (P>0.05) on water quality parameters, abundance of natural food (plankton, periphyton and benthos) and production of prawn and finfish. However, different fish combination had significant effects on pond ecology. The highest P04-P (P0.05) by the different stocking combinations of finfish. The net yield and survival of finfish were significantly higher in 100% tilapia ponds and lower in 100% rohu ponds resulting in 58% higher combined net yield (both prawn and finfish) in the former treatment during a 120-d culture period. This treatment gave the best economic return in terms of benefit-cost ratio while maize flour was used as CH source. In conclusion, maize flour can be used as an alternative cheap on-farm CH source for maintaining a high C:N ratio and tilapia driven re-suspension in C/N-CP system improves culture environment, natural food utilization, production and economic return, further enhancing economic sustainability of C/N-CP freshwater prawn farming system.