Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

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Effects of a commercial broiler enrichment programme with or without natural light on behaviour and other welfare indicators
Jong, I.C. de; Gunnink, H. - \ 2019
Animal 13 (2019)2. - ISSN 1751-7311 - p. 384 - 391.
activity - bales - chickens - exploration - perches

Commercial broiler production systems based on market initiatives to improve animal welfare beyond minimum legal requirements have emerged in several European countries. A common factor in the ‘higher welfare’ indoor systems is the application of environmental enrichment, with or without natural light, to promote locomotor activity and natural behaviours of the broiler chickens. In the current study, we evaluated the effects of a commercial enrichment programme for fast-growing indoor-housed broiler chickens, with or without natural light entering the broiler house. Enrichment materials were selected in relation to perceived minimal hygiene risk and ease of cleaning in between production cycles. Selected enrichments were a combination of wood shavings bales (1.5 bale/1000 chickens), round metal perches (2.7 m/1000 chickens) and metal chains as pecking objects (1/1000 chickens). Three treatments were studied: control (C) without enrichment and natural light, enriched (E) with enrichments as previously defined but without natural light and enriched plus natural light (EL) with enrichments as previously defined and natural light entrance. The experiment was carried out during five subsequent production cycles on one commercial broiler farm with three identical houses. EL could only be assigned to the middle house that was equipped with roof windows (light entrance area: 3% of floor space). C and E were in the two outer houses (alternated in between production cycles). Behaviour was observed during daytime at days 25 and 39 of age by scan sampling. Lameness, footpad dermatitis, hock burn, cleanliness and injuries were scored at the same ages, in addition to the response of the chickens to a novel object. Results showed that the treatments only affected broiler behaviour. E flocks showed significantly more resting as compared with EL and C. EL flocks showed significantly more walking, exploration and foraging behaviour as compared with E and C. Thus, broiler activity was highest in the EL treatment and lowest in the E treatment, with the C treatment in between. No treatment effects were found on the other welfare indicators and only a few tendencies for treatment effects were found for the novel object test, with E birds tending to be more reluctant to approach the object as compared with EL and C birds. We concluded that providing environmental enrichment and natural light-stimulated activity and natural behaviours in broiler chickens, whereas providing enrichment only seemed to have the opposite effect as compared with control flocks without enrichment.

Non-Typhoidal Salmonella Colonization in Chickens and Humans in the Mekong Delta of Vietnam
Trung, N.V. ; Carrique-Mas, J.J. ; Nghia, N.H. ; Tu, L.T.P. ; Mai, H.H. ; Tuyen, H.T. ; Campbell, J. ; Nhung, N.T. ; Nhung, H.N. ; Minh, P.V. ; Chieu, T.T.B. ; Hieu, T.Q. ; Mai, N.T.N. ; Baker, S. ; Wagenaar, J.A. ; Hoa, N.T. ; Schultsz, C. - \ 2017
Zoonoses and Public Health 64 (2017)2. - ISSN 1863-1959 - p. 94 - 99.
antimicrobial resistance - chickens - colonization - humans - Non-typhoidal Salmonella - Vietnam
Salmonellosis is a public health concern in both the developed and developing countries. Although the majority of human non-typhoidal Salmonella enterica (NTS) cases are the result of foodborne infections or person-to-person transmission, NTS infections may also be acquired by environmental and occupational exposure to animals. While a considerable number of studies have investigated the presence of NTS in farm animals and meat/carcasses, very few studies have investigated the risk of NTS colonization in humans as a result of direct animal exposure. We investigated asymptomatic NTS colonization in 204 backyard chicken farms, 204 farmers and 306 matched individuals not exposed to chicken farming, in southern Vietnam. Pooled chicken faeces, collected using boot or handheld swabs on backyard chicken farms, and rectal swabs from human participants were tested. NTS colonization prevalence was 45.6%, 4.4% and 2.6% for chicken farms, farmers and unexposed individuals, respectively. Our study observed a higher prevalence of NTS colonization among chicken farmers (4.4%) compared with age-, sex- and location- matched rural and urban individuals not exposed to chickens (2.9% and 2.0%). A total of 164 chicken NTS strains and 17 human NTS strains were isolated, and 28 serovars were identified. Salmonella Weltevreden was the predominant serovar in both chickens and humans. NTS isolates showed resistance (20–40%) against tetracycline, chloramphenicol, sulfamethoxazole-trimethoprim and ampicillin. Our study reflects the epidemiology of NTS colonization in chickens and humans in the Mekong delta of Vietnam and emphasizes the need of larger, preferably longitudinal studies to study the transmission dynamics of NTS between and within animal and human host populations.
Indirect calorimetry during incubation of hatching eggs
Brand, H. van den; Heetkamp, M.J.W. ; Kemp, B. - \ 2015
In: Indirect Calorimetry : Techniques, computations and applications / W.J.J., Gerrits, E., Labussière, Wageningen : Wageningen Academic Publishers - ISBN 9789086862610 - p. 231 - 246.
chickens - stable isotopes - oxygen - carbon dioxide - eggshell temperature
Indirect calorimetry can be used during incubation of avian eggs to monitor the quality of the incubation process, the development of the embryo and the utilization of nutrients. Indirect calorimetry has several benefits above direct calorimetry, particularly in hatching eggs. However, to obtain reliable measurements, some aspects of indirect calorimetry need to be taken into account. First, some attention is given to the use of respiration chambers for only one single egg or more eggs at the same time, with the advantages and disadvantages. Furthermore, attention is paid to the importance of using embryo or eggshell temperature as a tool to adjust the temperature in the respiration chamber. Since there is a strong relationship between embryo temperature and heat production (Q), the incubator temperature should be controlled depending on the desired eggshell temperature. Additionally, it is important to consider oxygen and carbon dioxide levels in the chamber, as low partial O2 pressure is related to incubation at high altitude and high CO2 levels can result from insufficient ventilation. Besides abiotic factors affecting Q, such as temperature, biotic factors, like egg weight and age of the breeder, affect Q as well. Finally, the use of stable isotopes during incubation to determine oxidation of different nutrients during the incubation process will be addressed. We conclude that indirect calorimetry during incubation of hatching eggs can give insight in the development of the embryo and the utilization of egg nutrients throughout incubation. However, to prevent misinterpretation of the results, some incubation factors (like temperature, O2 and CO2 concentration) and egg characteristics (like weight, breed and breeder age) need to be monitored and controlled.
Early life microbial colonization of the gut and intestinal development differ between genetically divergent broiler lines
Schokker, D. ; Veninga, G. ; Vastenhouw, S.A. ; Bossers, A. ; Bree, F.M. de; Kaal-Lansbergen, L.M.T.E. ; Rebel, J.M.J. ; Smits, M.A. - \ 2015
BMC Genomics 16 (2015). - ISSN 1471-2164
salmonella-enteritidis colonization - innate immune responsiveness - pro-inflammatory cytokine - barrier function - gastrointestinal-tract - epithelial-cells - host genotype - double-blind - chickens - resistance
Host genetic makeup plays a role in early gut microbial colonization and immune programming. Interactions between gut microbiota and host cells of the mucosal layer are of paramount importance for a proper development of host defence mechanisms. For different livestock species, it has already been shown that particular genotypes have increased susceptibilities towards disease causing pathogens. The objective of this study was to investigate the impact of genotypic variation on both early microbial colonization of the gut and functional development of intestinal tissue. From two genetically diverse chicken lines intestinal content samples were taken for microbiota analyses and intestinal tissue samples were extracted for gene expression analyses, both at three subsequent time-points (days 0, 4, and 16).
Influence of separate feeding of calcium on nutrient digestibility, energy utilisation and performance of young broilers fed pelleted wheat-based diets
Abdollahi, M.R. ; Dalen, A.B.J. van; Hendriks, W.H. ; Ravindran, V. - \ 2015
Animal Feed Science and Technology 205 (2015). - ISSN 0377-8401 - p. 122 - 130.
phytate phosphorus hydrolysis - nonphytate phosphorus - phytic acid - chickens - ph - efficacy - appetite - availability - consequences - ingredients
Six broiler starter diets, based on wheat and soybean meal, were formulated to contain 1.1 2.0, 4.0, 6.0, 8.0 and 10.0 g calcium (Ca)/kg. All diets were equivalent in respect of total and non-phytate phosphorus contents (5.4 and 3.0 g/kg, respectively). The influence of dietary treatments on the growth performance, coefficient of apparent ileal digestibility (CAID) of nitrogen (N), starch, fat and phosphorus (P), Ca retention and apparent metabolisable energy (AME) in broiler starters was evaluated. A total of 288, one-day-old male broilers (Ross 308) were allocated to 36 cages (8 birds/cage), and cages were randomly assigned to 6 dietary treatments. Birds were also provided with a source of Ca in a separate feed trough. Birds fed the diet with 1.1 g Ca/kg gained more (P0.05) feed per unit gain. During d 8 to 14, d 15 to 21, and over the entire trial period of 21 d, birds fed Ca-deficient (6.0 g Ca/kg and less) diets consumed more (P0.05) of dietary Ca on the retention of Ca and ash, AME and toe ash. The present data suggest that feeding broilers low Ca diets with access to a separate Ca source, is advantageous in terms of broiler performance, while maintaining bone mineralisation. The data also demonstrate that the provision of separate Ca source may hold promise for reducing the dietary P contents.
Fat coating of Ca butyrate results in extended butyrate release in the gastrointestinal tract of broilers
Borne, J.J.G.C. van den; Heetkamp, M.J.W. ; Buyse, J. ; Niewold, T.A. - \ 2015
Livestock Science 175 (2015). - ISSN 1871-1413 - p. 96 - 100.
acid breath test - c-13-octanoic acid - chickens - absorption - passage
Based on its described beneficial effects on small and large intestinal epithelium, butyrate can be a very good alternative to antimicrobial growth promoters. Effective dietary application requires coating because the majority of uncoated butyrate is purportedly absorbed before reaching the proximal small intestine. Several studies using different protocols reported varying stomach passage times in chickens. In the present study, we compared feeding uncoated vs. fat coated [1-13C] labeled Ca butyrate, and compared the effect of butyrate coating with [1-13C] labeled octanoic acid which is an established indicator of stomach passage. By monitoring 13CO2 expiration continuously, we show that the majority (about 80%) of uncoated Ca butyrate is oxidized proximally of the small intestine, and that base line levels were reached after 6 h. Fat coating of Ca butyrate resulted in reduced proximal oxidation (from about 80% to about 45%), and in an extended release pattern of 13CO2 from butyrate similar to that of octanoic acid, and that the return to base line levels was extended to 12 h. This indicated that fat coating of butyrate results in absorption along the entire intestinal tract in broilers, offering an explanation for the described beneficial effects as a growth promoter.
Indirect Genetic Effects for Growth Rate in Domestic Pigs Alter Aggressive and Manipulative Biting Behaviour
Camerlink, I. ; Ursinus, W.W. ; Bijma, P. ; Kemp, B. ; Bolhuis, J.E. - \ 2015
Behavior Genetics 45 (2015)1. - ISSN 0001-8244 - p. 117 - 126.
social breeding values - multilevel selection - environment interactions - interacting phenotypes - housing systems - traits - performance - chickens - populations - serotonin
Indirect genetic effects (IGEs) are heritable effects of an individual on phenotypic values of others, and may result from social interactions. We determined the behavioural consequences of selection for IGEs for growth (IGEg) in pigs in a G × E treatment design. Pigs (n = 480) were selected for high versus low IGEg with a contrast of 14 g average daily gain and were housed in either barren or straw-enriched pens (n = 80). High IGEg pigs showed from 8 to 23 weeks age 40 % less aggressive biting (P = 0.006), 27 % less ear biting (P = 0.03), and 40 % less biting on enrichment material (P = 0.005). High IGEg pigs had a lower tail damage score (high 2.0; low 2.2; P = 0.004), and consumed 30 % less jute sacks (P = 0.002). Selection on high IGEg reduced biting behaviours additive to the, generally much larger, effects of straw-bedding (P <0.01), with no G × E interactions. These results show opportunities to reduce harmful biting behaviours in pigs.
Silent spread of highly pathogenic Avian Influenza H5N1 virus amongst vaccinated commercial layers
Poetri, O.N. ; Boven, M. ; Claassen, I.J.T.M. ; Koch, G. ; Wibawan, I.W. ; Stegeman, A. ; Broek, J. van den; Bouma, A. - \ 2014
Research in Veterinary Science 97 (2014)3. - ISSN 0034-5288 - p. 637 - 641.
transmission - chickens - poultry - evolution
The aim of this study was to determine whether a single vaccination of commercial layer type chickens with an inactivated vaccine containing highly pathogenic avian influenza virus strain H5N1 A/chicken/Legok/2003, carried out on the farm, was sufficient to protect against infection with the homologous virus strain. A transmission experiment was carried out with pairs of chicken of which one was inoculated with H5N1 virus and the other contact-exposed. Results showed that the majority of the vaccinated birds developed haemagglutination inhibition (HI) titres below 4log2. No clinical signs were observed in the vaccinated birds and virus shedding was limited. However, nearly all vaccinated birds showed a four-fold or higher increase of HI titres after challenge or contact-exposure, which is an indication of infection. This implies that virus transmission most likely has occurred. This study showed that a single vaccination applied under field conditions induced clinical protection, but was insufficient to induce protection against virus transmission, suggesting that silent spread of virus in vaccinated commercial flocks may occur. (C) 2014 Elsevier Ltd. All rights reserved.
Protein source and dietary structure influence growth performance, gut morphology, and hindgut fermentation characteristics in broilers
Qaisrani, S.N. ; Moquet, P.C.A. ; Krimpen, M.M. van; Kwakkel, R.P. ; Verstegen, M.W.A. ; Hendriks, W.H. - \ 2014
Poultry Science 93 (2014)12. - ISSN 0032-5791 - p. 3053 - 3064.
feed particle-size - nutrient digestibility - amino-acids - canola-meal - parameters - chickens - wheat - corn - pigs - starters
An experiment with 210 male (Ross 308) 1-d-old broilers was conducted to test the hypothesis that a coarse diet improves performance of broilers fed a poorly digestible protein source. A highly digestible diet based on soybean meal was gradually replaced by a low digestible diet based on rapeseed meal (RSM) in 5 steps (RSM-0%, RSM-25%, RSM-50%, RSM-75%, and RSM-100%). Two diet structures (fine and coarse) were used as an additional factor. These 2 factors and their interactions were tested at different ages in a factorial arrangement with 10 dietary treatments. An increase in indigestible dietary protein negatively affected feed intake (P = 0.003), BW gain (P = 0.008), and feed conversion ratio (P = 0.034). This increase in dietary indigestible protein contents resulted in a decrease (P = 0.001) in total cecal volatile fatty acid concentration from 209.1 to 125.9 mmol/kg of DM digesta in broilers with increasing RSM in diets. Increase in the indigestible protein level, from RSM-0% to RSM-100%, resulted in a decrease (P = 0.042) in villus heights (1,782 vs. 1,574 µm), whereas crypt depths increased (P = 0.021; 237 vs. 274 µm). A coarse diet improved feed intake (P = 0.006), BW gain (P = 0.014), and feed conversion ratio (P = 0.009). Broilers fed coarse diets had approximately 11, 24, and 10% lower relative empty weights of the crop, proventriculus, and jejunum, respectively, whereas a 15% heavier gizzard was found compared with those fed the fine diets. Dietary coarseness resulted in approximately 16% lower gizzard pH, 21% greater villus heights, 27% lower crypt depths, 24% reduced branched-chain fatty acids, and 12% lower biogenic amines in the cecal digesta compared with broilers fed fine diets. In conclusion, feeding coarse particles improved broiler performance irrespective of digestibility of the diet. Hindgut protein fermentation can be reduced by coarse grinding of the diet.
Development of ileal cytokine and immunoglobulin expression levels in response to early feeding in broilers and layers
Simon, K. ; Vries Reilingh, G. de; Kemp, B. ; Lammers, A. - \ 2014
Poultry Science 93 (2014)12. - ISSN 0032-5791 - p. 3017 - 3027.
immune-responses - gut microbiota - intestinal microbiota - natural antibodies - innate immunity - delayed access - axenic mice - performance - chickens - system
Provision of feed in the immediate posthatch period may influence interaction between intestinal microbiota and immune system, and consequently immunological development of the chick. This study addressed ileal immune development in response to early feeding in 2 chicken breeds selected for different production traits: broilers and layers. Chicks of both breeds either received feed and water immediately posthatch or were subjected to a 72-h feed and water delay. Ileal cytokine and immunoglobulin mRNA expression levels were determined at different time points. Effects of early feeding were limited, but breeds differed strikingly regarding cytokine and immunoglobulin expression levels. Cytokine expression levels in broilers were low compared with layers and showed a transient drop in the second to third week of life. In contrast, broilers showed considerably higher expression levels of IgA, IgM, and IgY. These findings indicate that the 2 breeds use different immune strategies, at least on the ileal level.
Evaluation of free water and water activity measurements as functional alternatives to total moisture content in broiler excreta and litter samples
Hoeven-Hangoor, E. van der; Rademaker, C. ; Paton, N.D. ; Verstegen, M.W.A. ; Hendriks, W.H. - \ 2014
Poultry Science 93 (2014)7. - ISSN 0032-5791 - p. 1782 - 1792.
sugar-beet pulp - gastrointestinal-tract - oat hulls - nonstarch polysaccharides - growth-performance - poultry houses - low-viscosity - chickens - ammonia - diets
Litter moisture contents vary greatly between and within practical poultry barns. The current experiment was designed to measure the effects of 8 different dietary characteristics on litter and excreta moisture content. Additionally, free water content and water activity of the excreta and litter were evaluated as additional quality measures. The dietary treatments consisted of nonstarch polysaccharide content (NSP; corn vs. wheat), particle size of insoluble fiber (coarse vs. finely ground oat hulls), viscosity of a nonfermentable fiber (low- and high-viscosity carboxymethyl cellulose), inclusion of a clay mineral (sepiolite), and inclusion of a laxative electrolyte (MgSO4). The 8 treatments were randomly assigned to cages within blocks, resulting in 12 replicates per treatment with 6 birds per replicate. Limited effects of the dietary treatments were noted on excreta and litter water activity, and indications were observed that this measurement is limited in high-moisture samples. Increasing dietary NSP content by feeding a corn-based diet (low NSP) compared with a wheat-based diet (high NSP) increased water intake, excreta moisture and free water, and litter moisture content. Adding insoluble fibers to the wheat-based diet reduced excreta and litter moisture content, as well as litter water activity. Fine grinding of the oat hulls diminished the effect on litter moisture and water activity. However, excreta moisture and free water content were similar when fed finely or coarsely ground oat hulls. The effects of changing viscosity and adding a clay mineral or laxative deviated from results observed in previous studies. Findings of the current experiment indicate a potential for excreta free water measurement as an additional parameter to assess excreta quality besides total moisture. The exact implication of this parameter warrants further investigation.
Heterogeneity in consumer perceptions of the animal friendliness of broiler production systems
Jonge, J. de; Trijp, J.C.M. van - \ 2014
Food Policy 49 (2014)Pt. 1. - ISSN 0306-9192 - p. 174 - 185.
welfare - preferences - meat - standards - stakeholder - interests - attitudes - chickens - values - food
Animal welfare-based product differentiation through private sector initiatives has led to the introduction of ‘compromise’ meat products, which are produced at beyond regulatory standards for animal welfare, but are cheaper than organic meat. A variety of production system characteristics serve as parameters to achieve higher animal welfare standards. Food policies will be more effective if they position compromise products on those production system characteristics that really matter to (segments of) consumers. The present study identifies that three market segments may be discerned; one that takes a more inclusive perspective on animal welfare, and two that take a more heuristic approach by viewing animal friendliness from a more uni-dimensional perspective (animal space vs. slaughter method). These segments do not only differ in their perception of animal welfare, but also regarding their background characteristics. An interesting finding of the research is that the different segments accord in their perceptions of overall animal welfare levels, but do so for different reasons. In terms of food policy implications this means that the further development of compromise products would benefit from communicating more specific information on animal space and slaughter method, in addition to the overall star-based animal welfare classification. Such communication would serve well to both 50% of the market that takes a more balanced and integrated view on animal welfare and the other half of the market that takes a more uni-dimensional perspective (space vs. slaughter method).
Effects of inclusion of hydrolyzed yeast on the immune response and performance of piglets after weaning
Molist, F. ; Eerden, E. van; Parmentier, H.K. ; Vuorenmaa, J. - \ 2014
Animal Feed Science and Technology 195 (2014). - ISSN 0377-8401 - p. 136 - 141.
growth-performance - saccharomyces-cerevisiae - natural antibodies - weanling pigs - nutrient digestibility - weaned piglets - supplementation - polysaccharides - challenge - chickens
The aim of this study was to examine whether yeast derivative (YD) based on brewery yeast hydrolyzate added to a post-weaning diet affected performance and immune responses in weaning pigs. One hundred and twenty pigs were allocated to 20 pens, taking initial body weight into account, and were distributed into two groups as follows: a negative control diet and the same diet supplemented with 2 g YD/kg. The YD used was Progut® (Hankkija Oy/Suomen Rehu, Hyvinkää, Finland). At days 7 and 21 of the experiment, half of the piglets per group were challenged intramuscularly with 1 mL of a solution of 20% sheep red blood cells (SRBC) in sterile phosphate buffered saline (PBS). At days 0, 14, 21 and 28 of the experiment, blood samples from the challenged piglets were obtained and acute-phase proteins (Pig-MAP), natural antibodies of the IgM- and IgG-isotype binding to keyhole limpet hemocyanin (KLH), and agglutinating antibody titers to SRBC were measured. Yeast derivative inclusion improved feed conversion ratio (P=0.025) for the overall period, tended to increase IgG (P=0.087) and IgM (P=0.061) antibodies in serum-binding KLH, and increased (P=0.037) SRBC agglutination titers. Collectively, these data suggest that YD supplementation as 2 g Progut®/kg to weanling pigs triggered the immune system to a more responsive state without penalizing the animal performance which could potentially be beneficial for overcoming disease challenges. Piglets fed with 2 g Progut®/kg for 28 days after weaning also showed an improvement in feed conversion ratio.
Effect of eggshell temperature throughout incubation on broiler hatchling leg bone development
Pol, C.W. van der; Roovert-Reijrink, I.A.M. van; Maatjens, C.M. ; Anker, I. van den; Kemp, B. ; Brand, H. van den - \ 2014
Poultry Science 93 (2014)11. - ISSN 0032-5791 - p. 2878 - 2883.
oxygen concentration - gallus-gallus - growth - chickens - period - embryos - health
Leg problems in broiler chickens may partly be prevented by providing optimal circumstances for skeletal development during incubation. One of the factors demonstrated to affect bone development is eggshell temperature (EST), which provides a reliable reflection of embryo temperature. The present experiment aimed to investigate the effect of EST on development and asymmetry of the femur, tibia, and metatarsus in broiler chicken hatchlings. Eggs were incubated from d 0 until hatch at 1 of 4 EST: low (36.9°C), normal (37.8°C), high (38.6°C), and very high (39.4°C). At hatch, chick quality was determined in terms of chick length, yolk-free body mass, navel score, and organ weights. Tibia, femur, and metatarsus were weighed, their length and width (mediolateral diameter) and depth (craniocaudal diameter) at the middle of the shaft were measured, and their ash content was determined. Relative asymmetry of the leg bones was determined from their relative dimensions. Hatchability, chick quality, and organ development were lower for very high EST compared with all other treatments. Very high EST resulted in lowest tibia and metatarsus lengths (-3.1 to -8.4%) compared with all other treatments, and lower metatarsus weight (-9.1%) and femur length (-4.9%) compared with high EST. Relative asymmetry and ash content did not differ among treatments and no relation between EST and bone parameters was found. To conclude, very high EST resulted in lower bone development, hatchability, and chick quality. Few differences in bone development and chick quality were found between low, normal, and high EST.
Understanding carbohydrate structures fermented or resistant to fermentation in broilers fed rapeseed (Brassica napus) meal to evaluate the effect of acid treatment and enzyme addition
Pustjens, A.M. ; Vries, S. de; Schols, H.A. ; Gerrits, W.J.J. ; Kabel, M.A. - \ 2014
Poultry Science 93 (2014)4. - ISSN 0032-5791 - p. 926 - 934.
nonstarch polysaccharides - pectic substances - canola-meal - xyloglucan - chickens
Unprocessed and acid-extruded rapeseed meal (RSM) was fed to broiler chickens, with and without addition of commercial pectolytic enzymes. Nonstarch polysaccharide (NSP) fermentability and unfermented NSP structures from RSM were studied in the excreta in detail. From unprocessed RSM, 24% of the nonglucose polysaccharides could be fermented. Acid treatment did not have a significant effect, but enzyme addition did improve fermentability to 38%. Most likely, the significant increase in NSP fermentability can be ascribed to the addition of pectolytic enzymes, which decreased branchiness of the water-soluble arabinan. Mainly xyloglucan, (glucurono-)xylan, (branched) arabinan, and cellulose remained in the excreta. The proportion of unextractable carbohydrates increased in excreta from broilers fed acid-extruded RSM. Probably, acid extrusion resulted in a less accessible NSP matrix, also decreasing the accessibility for pectolytic enzymes added in the diet. During alkaline extraction of the excreta, 39 to 52% (wt/wt) of the insoluble carbohydrates was released as glucosyl- and uronyl-rich carbohydrates, probably originally present via ester linkages or hydrogen bonding within the cellulose-lignin network. These linkages are expected to hinder complete NSP fermentation and indicate that digestibility of RSM may benefit substantially from an alkaline treatment or addition of esterases.
Effects of processing technologies and pectolytic enzymes on degradability of nonstarch polysaccharides from rapeseed meal in broilers
Vries, S. de; Pustjens, A.M. ; Kabel, M.A. ; Kwakkel, R.P. ; Gerrits, W.J.J. - \ 2014
Poultry Science 93 (2014)3. - ISSN 0032-5791 - p. 589 - 598.
dietary fiber components - canola-meal - metabolizable energy - nutritive-value - seeded canola - soybean-meal - poultry - digestibility - chickens - pigs
Rapeseed meal (RSM) contains a high level of nonstarch polysaccharides (NSP) that are not well degraded in poultry and interfere with digestion of other nutrients as protein, starch, and fat. By altering physicochemical properties of NSP from RSM, processing and enzyme technologies might improve digestive utilization of RSM, enhancing its potential as a source of nutrients in poultry diets. The effects of wet milling and extrusion in combination with pectolytic enzymes on the degradability of RSM in broilers were investigated in a 3 × 2 factorial arrangement. Wet milling and extrusion did not affect total tract apparent digestibility of DM, CP, crude fat, and nonglucose polysaccharides (NGP). Addition of pectolytic enzymes did not affect total tract apparent digestibility of CP and crude fat, but improved degradability of NGP by 9 to 20% units (P <0.001), independent of prior technological processing of RSM. This coincided with an increased NGP concentration in the ceca (4 to 7 g/g of cobalt, P <0.001), indicating that more NGP were solubilized such that they could enter the ceca and become available for fermentation. Particle size reduction facilitated solubilization of polysaccharides from RSM, increasing the concentration of NGP found in the ceca (4 g/g of cobalt, P = 0.008). Without help of additional pectolytic enzymes, those solubilized structures could, however, still not be degraded by the cecal microbiota. Feed intake, BW gain, and feed conversion ratio were not affected. No interaction between processing technologies and enzyme addition was found. Apparently, the processing technologies studied were not facilitating accessibility of NSP to pectolytic enzymes added to the feed in vivo.
Cone restraining and head-only electrical stunning in broilers: Effects on physiological responses and meat quality
Lambooij, E. ; Reimert, H.G.M. ; Verhoeven, M.T.W. ; Hindle, V.A. - \ 2014
Poultry Science 93 (2014)3. - ISSN 0032-5791 - p. 512 - 518.
water-bath - slaughter - transport - poultry - feasibility - parameters - mortality - chickens - bruises - stress
Two experiments were conducted to evaluate a new electrical stunning system for broilers. The objective of the first experiment was to evaluate the behavioral, neural, and physiological responses of 27 broilers after head-only electrical stunning while their bodies were restrained in cone-shaped holders. In the second experiment, quality of meat from 30 broilers after headonly electrical stunning in a cone-shaped restrainer was compared with that from 30 broilers stunned in a conventional water bath. Broilers were restrained in the cone with their heads positioned to facilitate a correct stun, followed by a neck cut by hand. After stunning, each broiler displayed a tonic phase, followed by minimal brain activity during bleeding. On average, heart rate was 258 ± 51 beats/min before stunning. The heart was observed to malfunction after cutting. According to the correlation dimension analyses, the score remained low. Within a confidence limit of 95%, taking into account the number of birds with a reliable electroencephalogram (n = 27), the chance of an effective stun and exsanguination with all broilers lies between 0.90 and 1.00 using a sinusoidal AC current of 264 ± 29 mA (~130 V). After a brief learning period, operators were able to easily position the broilers in the cone in a commercial setting. The pH after chilling was 0.5 units lower (P <0.05) in the head-only stunned group compared with the group stunned in a conventional water bath. After head-only stunning, 60% of breast fillets showed no blood splashes and 3% showed severe blood splashes compared with 20 and 27% after conventional water bath stunning. No differences in temperature and color were observed between the 2 groups. It is concluded that broilers could be restrained in a cone, followed by correct head-only stunning, neck-cutting, and unconscious shackling afterward under laboratory and commercial slaughterhouse conditions. When this procedure was used, meat quality was better compared with broilers stunned in the conventional water bath.
Effects of growth pattern and dietary protein level during rearing on feed intake, eating time, eating rate, behavior, plasma corticosterone concentration, and feather cover in broiler breeder females during the rearing and laying period
Emous, R.A. van; Kwakkel, R.P. ; Krimpen, M.M. van; Hendriks, W.H. - \ 2014
Applied Animal Behaviour Science 150 (2014)1. - ISSN 0168-1591 - p. 44 - 54.
food restriction - welfare assessment - improve - indexes - hunger - age - performance - parameters - allocation - chickens
An experiment was conducted to evaluate the effect of growth patterns (GP) and dietary crude protein levels (CP) during rearing (2–22 weeks of age) on feed intake, eating time, eating rate, behavior, plasma corticosterone concentration, and feather cover in broiler breeder females during the rearing and laying period. A total of 768 day-old Ross 308 broiler breeder chicks, of which 288 hens were followed during the laying period, were allotted to 6 different treatments during the rearing period according to a 2 × 3 factorial design, with 8 replicates (pens) per treatment. Two growth patterns were followed by a restricted feeding regime up to a target body weight (BW) at 20 weeks of age of 2200 g (standard growth pattern = SGP) and 2400 g (high growth pattern = HGP) and 3 dietary protein levels (high = CPh, medium = CPm, and low = CPl). During lay, all birds were fed a standard breeder diet and followed a standard growth pattern. During rearing, HGP birds were fed on average 6.5% more feed than SGP birds. In HGP birds, eating time (min/day) during the rearing period increased by 17%, whereas eating rate (g feed/min) decreased by 8%, compared to SGP birds. This prolonged feeding behavior of HGP birds, but stereotypic object pecking and animal pecking was not reduced. Feather cover was not affected by growth pattern during the rearing and laying period. Only at 16 weeks of age a lower plasma corticosterone concentration was found for the HGP birds. HGP birds showed more feeding and sitting behavior, but less foraging behavior during the rearing period, while during the laying period only more walking behavior was observed. In order to maintain target weights, feed intake levels of CPm and CPl during rearing were set 4.6 and 10.0% higher than CPh, whereas eating time was increased by 22 and 63% and eating rate was decreased by 9 and 26%, respectively. A prolonged eating time during rearing for CPm and CPl birds resulted in more time spend feeding and resting and less stereotypic object pecking and animal pecking compared to CPh birds during rearing. In contrast to the rearing period, feed intake and eating time were not affected by CP level during rearing at 22 weeks of age, whereas eating rate was increased by 8 and 16% for CPm and CPl, respectively, compared to CPh. At 27 weeks of age the effect of CP level during rearing on eating rate had disappeared. Plasma corticosterone concentrations were not affected by dietary protein level during the rearing and laying period. Feather cover was inferior by lowering the dietary protein level, in particularly during the first 11 weeks of rearing. No effect of GP was found on feather cover. It is concluded that dietary protein levels positively affected some behavioral traits during the rearing period, whereas these traits were only slightly affected by growth patterns. However, the physiological parameter (plasma corticosterone concentration) was not affected.
Presence of ESBL/AmpC-producing Escherichia coli in the broiler production pyramid: a descriptive study.
Dierikx, C.M. ; Goot, J.A. van der; Smith, H.E. ; Kant, A. ; Mevius, D.J. - \ 2013
PLoS ONE 8 (2013). - ISSN 1932-6203 - 11 p.
spectrum-beta-lactamase - antimicrobial agents - resistance - chickens - poultry - enterobacteriaceae - epidemiology - transmission - humans - impact
Broilers and broiler meat products are highly contaminated with extended spectrum beta-lactamase (ESBL) or plasmid-mediated AmpC beta-lactamase producing Escherichia coli and are considered to be a source for human infections. Both horizontal and vertical transmission might play a role in the presence of these strains in broilers. As not much is known about the presence of these strains in the whole production pyramid, the epidemiology of ESBL/AmpC-producing E. coli in the Dutch broiler production pyramid was examined. Cloacal swabs of Grandparent stock (GPS) birds (one-/two-days (breed A and B), 18 and 31 weeks old (breed A)), one-day old Parent stock birds (breed A and B) and broiler chickens of increasing age (breed A) were selectively cultured to detect ESBL/AmpC-producing isolates. ESBL/AmpC-producing isolates were found at all levels in the broiler production pyramid in both broiler breeds examined. Prevalence was already relatively high at the top of the broiler production pyramid. At broiler farms ESBL/AmpC producing E. coli were still present in the environment of the poultry house after cleaning and disinfection. Feed samples taken in the poultry house also became contaminated with ESBL/AmpC producing E. coli after one or more production weeks. The prevalence of ESBL/AmpC-positive birds at broiler farms increased within the first week from 0–24% to 96–100% independent of the use of antibiotics and stayed 100% until slaughter. In GPS breed A, prevalence at 2 days, 18 weeks and 31 weeks stayed below 50% except when beta-lactam antibiotics were administered. In that case prevalence increased to 100%. Interventions minimizing ESBL/AmpC contamination in broilers should focus on preventing horizontal and vertical spread, especially in relation to broiler production farms.
Avian influenza trasnmission risks: analysis of biosecuritiy measures and contact structure in Dutch poultry farming
Ssematimba, A. ; Hagenaars, T.H.J. ; Wit, J.J. de; Ruiterkamp, F. ; Fabri, T.H.F. ; Stegeman, J.A. ; Jong, M.C.M. de - \ 2013
Preventive Veterinary Medicine 109 (2013)1-2. - ISSN 0167-5877 - p. 106 - 115.
potential pathways - virus h7n7 - a viruses - netherlands - epidemic - chickens - georgia - canada - japan
In the 2003 epidemic of highly pathogenic avian influenza in Dutch poultry, between-farm virus transmission continued for considerable time despite control measures. Gaining more insight into the mechanisms of this spread is necessary for the possible development of better control strategies. We carried out an in-depth interview study aiming to systematically explore all the poultry production activities to identify the activities that could potentially be related to virus introduction and transmission. One of the between-farm contact risks that were identified is the movement of birds between farms during thinning with violations of on-farm biosecurity protocols. In addition, several other risky management practices, risky visitor behaviours and biosecurity breaches were identified. They include human and fomite contacts that occurred without observing biosecurity protocols, poor waste management practices, presence of other animal species on poultry farms, and poor biosecurity against risks from farm neighbourhood activities. Among the detailed practices identified, taking cell phones and jewellery into poultry houses, not observing shower-in protocols and the exchange of unclean farm equipment were common. Also, sometimes certain protocols or biosecurity facilities were lacking. We also asked the interviewed farmers about their perception of transmission risks and found that they had divergent opinions about the visitor- and neighbourhood-associated risks. We performed a qualitative assessment of contact risks (as transmission pathways) based on contact type, corresponding biosecurity practices, and contact frequency. This assessment suggests that the most risky contact types are bird movements during thinning and restocking, most human movements accessing poultry houses and proximity to other poultry farms. The overall risk posed by persons and equipment accessing storage rooms and the premises-only contacts was considered to be medium. Most of the exposure risks are considered to be similar for layer and broiler farms. Our results, including those on farmer opinions, are relevant for the communication with farmers and poultry-related businesses about practices and risks. We conclude by providing recommendations for improvement of control strategies.
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