Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    '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.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

    Records 1 - 20 / 132

    • help
    • print

      Print search results

    • export

      Export search results

    Check title to add to marked list
    Effects of breeder age and oxygen concentration during incubation on embryonic heat production and development, and post-hatch chick performance
    Molenaar, R. ; Nangsuay, A. ; Meijerhof, R. ; Anker-Hensen, I. van den; Heetkamp, M.J.W. ; Kemp, B. ; Brand, H. van den - \ 2017
    European Poultry Science 81 (2017). - ISSN 1612-9199 - p. 4 - 4.
    The interaction between carbon dioxide concentration and eggshell temperature during the second half of incubation in broiler chickens
    Brand, H. van den; Meijerhof, R. ; Heetkamp, M.J.W. ; Anker-Hensen, I. van den; Ooms, M. ; Kemp, B. - \ 2017
    European Poultry Science 81 (2017). - ISSN 1612-9199 - p. 23 - 23.
    Poultry - CO2 - eggshell - heat production - chicken quality
    Effects of breeder age, strain, and eggshell temperature on nutrient metabolism of broiler embryos
    Nangsuay, A. ; Meijerhof, R. ; Anker-Hensen, I. van den; Heetkamp, M.J.W. ; Kemp, B. ; Brand, H. van den - \ 2017
    Poultry Science 96 (2017)1. - ISSN 0032-5791 - p. 1891 - 1900.
    Breeder age and broiler strain influence the availability of nutrients and oxygen through yolk size and eggshell conductance, and the effects of these egg characteristics on nutrient metabolism might be influenced by eggshell temperature (EST). This study aims to determine effects of breeder age, strain, and EST on nutrient metabolism of embryos. A study was designed as a 2 × 2 × 2 factorial arrangement using four batches of in total 4,464 hatching eggs of 2 flock ages at 29 to 30 wk (young) and 54 to 55 wk (old) of Ross 308 and Cobb 500. EST of 37.8 (normal) or 38.9°C (high) was applied from incubation day 7 (E7) until hatching. Wet yolk weight was determined mainly by breeder age (P = 0.043). Energy content in yolk (P = 0.004) and albumen + yolk (P = 0.005) were higher in old flock eggs than in young flock eggs, but did not differ between broiler strains. Eggshell conductance was higher in Ross 308 eggs than in Cobb 500 eggs (P < 0.001). Old flock embryos used more energy (P = 0.046) and accumulated more energy into yolk free body mass (YFBM; P = 0.030) than young flock embryos, whereas heat production (HP), energy lost, and efficiency of converting energy used to YFBM (EYFB) did not differ. Ross 308 embryos used more energy (P = 0.006), had a higher energy lost (P = 0.010), and a higher HP between E15 to E18 (P < 0.05) than Cobb 500 embryos. Energy content in YFBM did not differ between strains and EYFB (P = 0.024) was lower in Ross 308 than in Cobb 500. High EST resulted in higher HP than low EST from E11 to E15 (P < 0.05), but not after E15. Amount of energy used (P = 0.006) and energy accumulated in the YFBM (P < 0.001) was lower for embryos incubated at an EST of 38.9 than that of 37.8°C, whereas EYFB did not differ. In conclusion, breeder age, broiler strain, and EST differentially influence embryonic metabolism and particularly the availability of oxygen could have contributed to these differences.
    Embryonic development and heat production
    Nangsuay, A. ; Meijerhof, R. ; Anker-Hensen, I. van den; Heetkamp, M.J.W. ; Kemp, B. ; Brand, H. van den - \ 2016
    International Hatchery Practice 30 (2016)3. - ISSN 0959-9363 - p. 17 - 17.
    Effects of breeder age, broiler strain, and eggshell temperature on development and physiological status of embryos and hatchlings
    Nangsuay, A. ; Meijerhof, R. ; Anker-Hensen, Ilona van den; Heetkamp, M.J.W. ; Souza Morita, V. De; Kemp, B. ; Brand, H. Van Den - \ 2016
    Poultry Science 95 (2016)7. - ISSN 0032-5791 - p. 1666 - 1679.
    Breeder age - Broiler strain - Eggshell temperature - Embryonic development

    Breeder age and broiler strain can influence the availability of nutrients and oxygen, particularly through differences in yolk size and shell conductance. We hypothesized that these egg characteristics might affect embryonic responses to changes in eggshell temperature (EST). This study aimed to investigate the effect of breeder age, broiler strain, and EST on development and physiological status of embryos. A study was designed as a 2 × 2 × 2 factorial arrangement using 4 batches of 1,116 hatching eggs of 2 flock ages at 29 to 30 wk (young) and 54 to 55 wk (old) of Ross 308 and Cobb 500. EST of 37.8 (normal) or 38.9°C (high) was applied from incubation d 7 (E7) until hatching. The results showed that breeder age rather than broiler strain had an influence on yolk size (P = 0.043). The shell conductance was higher in Ross 308 than in Cobb 500 (P <0.001). A high EST resulted in a higher yolk free body mass (YFBM) compared to the normal EST at E14 and E16, but at 3 h after hatch YFBM was lower when eggs were incubated at high EST compared to normal EST (all P <0.001). Cobb 500 eggs yielded embryos with a lower YFBM at E14, E18, and 3 h after hatch (all P <0.05) than Ross 308 eggs. Breeder age had no effect on YFBM, but the RSY weight was higher in embryos from the old flock compared to the young flock embryos at E14 and E16 (both P <0.05). A 3-way interaction among breeder age, strain, and EST was found, especially for incubation duration, navel quality, and relative heart and stomach weights at 3 h after hatch (all P <0.05). Based on the results obtained, we conclude that oxygen availability rather than nutrient availability determines embryonic development, and the egg characteristics affected embryonic responses to changes of EST, especially for variables related to chick quality.

    Are all eggs equal? : embryonic development and nutrient metabolism in chicken eggs of different origins
    Nangsuay, A. - \ 2016
    Wageningen University. Promotor(en): Bas Kemp, co-promotor(en): Henry van den Brand; R. Meijerhof. - Wageningen : Wageningen University - ISBN 9789462577749 - 213
    eggs - hens - broilers - characteristics - strains - embryonic development - nutrients - metabolism - hatcheries - poultry - nutrition physiology - eieren - hennen - vleeskuikens - karakteristieken - stammen (biologisch) - embryonale ontwikkeling - voedingsstoffen - metabolisme - broedinstallaties - pluimvee - voedingsfysiologie

    Hatching eggs, supplied to hatcheries are originating from different origins varying in breed, strain, and breeder age. These hatching eggs can be different in size, composition and eggshell properties, which might influence nutrient and O2 availability and consequently could affect embryonic development and nutrient metabolism. The aim of this thesis was therefore 1) to investigate effects of egg origin on nutrient and O2 availability, 2) to investigate effects of egg origins on nutrient metabolism and embryonic development and 3) to investigate consequences of different egg origins on the incubation process and hatching characteristics. In five studies, effects of different egg origins on nutrient and O2 availability, nutrient metabolism, embryo development and hatching characteristics were investigated. The first and second study focused on breeder age and egg size. The third study on breed; broilers and layers. The fourth study on broiler strain and the fifth study on breeder age, strain and eggshell temperature (EST). The overall findings in this thesis suggest that hatching eggs from different origins are not equal in availability of nutrients and O2. Nutrient availability is altered through variation in yolk size, especially by the effects of breeder age and breed. O2 availability is altered by differences in eggshell properties, which is influenced by especially breed and broiler strain. The availability of both nutrients and O2 plays a role on nutrient metabolism measured as embryonic heat production (HP) and consequently on embryonic development. Between incubation day (E) E7 and E14, both nutrient and O2 availability might affect nutrient metabolism as shown in the results of the broiler and layer comparison. Between E14 and hatching, the availability of O2 becomes the most determinant factor for nutrient metabolism and consequently for embryonic development. An increase in EST from 37.8 to 38.9°C from E7 onward resulted in an acceleration of nutrient metabolism and embryonic development until E16, but thereafter a high EST resulted in reduced yolk free body mass development. Embryos with an accelerated metabolic speed at an early stage of incubation, caused by an increased EST, might reach limited O2 availability at a higher magnitude than the embryos at a normal EST. As a result, nutrient metabolism is restricted and embryonic development is depressed. It can be concluded that not only the HP, but also the availability of O2 is crucial to be taken into account for developing incubator temperature. The principle is to obtain an optimal EST, which could maintain the balance between O2 requirement (driven by nutrient metabolism) and O2 availability for a continuing optimal nutrient metabolism to generate sufficient energy for embryonic development throughout incubation.

    Embryonic development and heat production of embryos from two modern broiler strains
    Nangsuay, A. ; Meijerhof, R. ; Anker-Hensen, I. van den; Heetkamp, M.J.W. ; Kemp, B. ; Brand, H. van den - \ 2015
    In: Abstract Book of the 2015 IFRG meeting and 7th Combined Workshop on Fundamental Physiology and Perinatal Development in Poultry. - Berlin, Germany : - p. 37 - 37.
    Developmental and physiological status of Cobb 500 and Ross 308 embryos
    Nangsuay, A. ; Meijerhof, R. ; Anker, I. van den; Heetkamp, M.J.W. ; Kemp, B. ; Brand, H. van den - \ 2015
    Development and nutrient metabolism of embryos from two modern broiler strains
    Nangsuay, A. ; Meijerhof, R. ; Anker, I. van den; Heetkamp, M.J.W. ; Kemp, B. ; Brand, H. van den - \ 2015
    Poultry Science 94 (2015)10. - ISSN 0032-5791 - p. 2546 - 2554.
    A progressive selection for broiler live and processing performance traits has changed broiler growth patterns during the post hatch period. However, limited information is available to understand whether changes have also occurred during the embryonic stages. This study aims to examine influences of broiler strain on nutrient availability, embryonic development, and nutrient metabolism during incubation. Hatching eggs of Ross 308 and Cobb 500 fast feathering were selected from breeder flocks aged 43 to 46 weeks at an egg weight range of 60 to 63 g. Eggs were obtained in 2 batches, 120 eggs per strain per batch. For each batch, 20 eggs per strain were used to determine egg composition and nutrient availability. The remaining eggs were incubated separately in one of 2 climate respiration chambers at an eggshell temperature of 37.8°C. The results showed that Ross 308 eggs had a higher yolk:albumen ratio with 0.9 g more yolk and 0.7 g less albumen than Cobb 500. Albumen + yolk of Ross 308 eggs had a higher dry matter (¿ = 0.24 g) and crude fat (¿ = 0.23 g) than that of Cobb 500 eggs, but a similar amount of crude protein. Albumen and yolk of Ross 308 eggs had a higher energy content (¿ = 8.9 kJ) compared to Cobb 500 eggs. At 3¿h after hatch, Ross 308 chicks were 0.2 cm longer and had a 0.6 g heavier yolk free body mass (YFBM) than Cobb 500 chicks. During incubation, Ross 308 embryos used 13.9 kJ more energy than Cobb 500, and the efficiency of converting energy used to YFBM (EYFB) was approximately 7.6% lower compared to Cobb 500. Ross 308 chicks hatched approximately 4¿h later and had less hepatic glycogen (¿ = 5 mg) than Cobb 500 chicks. It can be concluded that, Cobb 500 and Ross 308 differ in egg nutrient availability and have different trajectories for embryonic development and nutrient metabolism during incubation.
    Differences in egg nutrient availability, development, and nutrient metabolism of broiler and layer embryos
    Nangsuay, A. ; Molenaar, R. ; Meijerhof, R. ; Anker, I. van den; Heetkamp, M.J.W. ; Kemp, B. ; Brand, H. van den - \ 2015
    Poultry Science 94 (2015)3. - ISSN 0032-5791 - p. 415 - 423.
    heat-production - eggshell temperature - chicken embryos - oxygen concentration - protein-turnover - lipid-metabolism - incubation - growth - glycogen - energy
    Selection for production traits of broilers and layers leads to physiological differences, which may already be present during incubation. This study aimed to investigate the influence of strain (broiler vs layer) on egg nutrient availability, embryonic development and nutrient metabolism. A total of 480 eggs with an egg weight range of 62.0 to 64.0 g from Lohmann Brown Lite and Ross 308 breeder flocks of 41 or 42 weeks of age were selected in two batches of 120 eggs per batch per strain. For each batch, 30 eggs per strain were used to determine egg composition, including nutrient and energy content, and 90 eggs per strain were separately incubated in one of two climate respiration chambers at an eggshell temperature of 37.8°C. The results showed that broiler eggs had a higher ratio of yolk: albumen with 2.41 g more yolk and 1.48 g less albumen than layers. The yolk energy content of broiler eggs was 46.32 kJ higher than that of layer eggs, whereas total energy content of broiler eggs was 47.85 kJ higher compared to layer eggs. Yolk-free body mass at incubation day 16 and chick weight and length at hatch were higher in broilers compared to layers. Respiration quotient of broiler embryos was higher than layer embryos during incubation day 8 to incubation day 10. A 0.24 g lower residual yolk at the hatch of broiler embryos than for the layer embryos indicated that broiler embryos used more yolk and had a higher energy utilization and energy deposition in yolk-free body mass. Heat production of broiler embryos was higher than that of layer embryos from incubation day 12 to incubation day 18, but efficiency of converting egg energy used by embryos to form yolk-free body mass was similar. In conclusion, broiler and layer embryos have different embryonic development patterns, which affect energy utilization and embryonic heat production. However, the embryos are equal in efficiency of converting the energy used to yolk-free body mass.
    Embryonic development, energy utilization, and heat production of broiler and layer embryos
    Nangsuay, A. ; Meijerhof, R. ; Anker, I. van den; Heetkamp, M.J.W. ; Kemp, B. ; Brand, H. van den - \ 2014
    In: Abstract of the Poultry Science Association 103rd Annual Meeting. - - p. 55 - nr 162.
    Different selection traits of broiler and layer strains result in physiological differences that might be present during incubation. This study aims to investigate an influence of strain on egg composition, development, nutrient metabolism, and heat production (HP) of the embryos. Hatching eggs with an egg weight range of 62.0 to 64.0 g of Lohmann Brown lite and Ross 308 at 41 or 42 wk were selected in 2 batches of 120 eggs per strain. For each batch, 30 eggs of each strain were used for egg composition determination and 90 eggs were separately incubated in 1 of 2 climate respiration chambers with an eggshell temperature (EST) of 37.8 °C. Oxygen and carbon dioxide concentrations were measured in both chambers and in fresh air and the data was used for respiratory quotient (RQ) and heat production (HP) calculation. Embryonic development was determined at D16 and at 6 h post hatch. Gross energy determination was performed for albumen, yolk, residual yolk (RSY), and yolk free body (YFBM). Results showed that broiler eggs had a higher ratio of yolk: albumen with 2.41 g more yolk and 1.48 g less albumen than layers. Yolk energy content of broiler eggs was 42.86 kJ higher than that of layer eggs, whereas albumen energy content did not differ. As a result, energy in albumen + yolk of broiler eggs was 45.26 kJ higher than that of layer eggs. YFBM at D16 and at hatch, chick weight and chick length of broiler was higher than that of layer. RQ of broiler embryos was higher than layer embryos during D8 to D10. A slightly higher RSY weight of broiler embryos than layer embryos at D16 (0.8 g) and at hatch (0.2 g) indicated more yolk used, which resulted in more energy utilization and energy deposited into YFBM. Embryonic HP of broiler embryos was higher than that of layer from D12 to D18, but efficiency of converting energy used by embryos to YFBM was similar. In conclusion, broiler and layer embryos have different growth trajectory, which affect energy utilization and embryonic HP during incubation.
    Effects of eggshell temperature (EST) on embryonic development and residual yolk (RSY) of hatching eggs originating from young and old flock
    Nangsuay, A. ; Meijerhof, R. ; Kemp, B. ; Brand, H. van den - \ 2014
    In: Proceedings of the XIVth European Poultry Conference. - - p. 405 - 405.
    Influences of Breeder Age on Energy Utilization and Embryonic Heat Production
    Nangsuay, A. ; Meijerhof, R. ; Ruangpanit, Y. ; Kemp, B. ; Brand, H. van den - \ 2013
    In: Incubation and Fertility Research Group (IFRG) Meeting, 8 September 2013, Göttingen, Germany. - Göttingen, Germany : - p. 11 - 12.
    High Environmental Temperature Increases Glucose Requirement in the Developing Chicken Embryo
    Molenaar, R. ; Borne, J.J.G.C. van den; Hazejager, E. ; Kristensen, N.B. ; Heetkamp, M.J.W. ; Meijerhof, R. ; Kemp, B. ; Brand, H. van den - \ 2013
    PLoS ONE 8 (2013)4. - ISSN 1932-6203 - 12 p.
    eggshell temperature - oxygen concentration - broiler embryos - domestic-fowl - carbohydrate metabolism - gallus domesticus - tissue glycogen - late incubation - turkey embryos - liver
    Environmental conditions during the perinatal period influence metabolic and developmental processes in mammals and avian species, which could impact pre- and postnatal survival and development. The current study investigated the effect of eggshell temperature (EST) on glucose metabolism in broiler chicken embryos. Broiler eggs were incubated at a high (38.9°C) or normal (37.8°C) EST from day 10.5 of incubation onward and were injected with a bolus of [U-13C]glucose in the chorio-allantoic fluid at day 17.5 of incubation. After [U-13C]glucose administration, 13C enrichment was determined in intermediate pools and end-products of glucose metabolism. Oxidation of labeled glucose occurred for approximately 3 days after injection. Glucose oxidation was higher in the high than in the normal EST treatment from day 17.6 until 17.8 of incubation. The overall recovery of 13CO2 tended to be 4.7% higher in the high than in the normal EST treatment. An increase in EST (38.9°C vs 37.8°C) increased 13C enrichment in plasma lactate at day 17.8 of incubation and 13C in hepatic glycogen at day 18.8 of incubation. Furthermore, high compared to normal EST resulted in a lower yolk-free body mass at day 20.9 (-2.74 g) and 21.7 (-3.81 g) of incubation, a lower hepatic glycogen concentration at day 18.2 (-4.37 mg/g) and 18.8 (-4.59 mg/g) of incubation, and a higher plasma uric acid concentration (+2.8 mg/mL/+43%) at day 21.6 of incubation. These results indicate that the glucose oxidation pattern is relatively slow, but the intensity increased consistently with an increase in developmental stage of the embryo. High environmental temperatures in the perinatal period of chicken embryos increased glucose oxidation and decreased hepatic glycogen prior to the hatching process. This may limit glucose availability for successful hatching and could impact body development, probably by increased gluconeogenesis from glucogenic amino acids to allow anaerobic glycolysis
    Energy utilization and heat production of embryos from eggs originating from young and old broiler breeder flocks
    Nangsuay, A. ; Meijerhof, R. ; Ruangpanit, Y. ; Kemp, B. ; Brand, H. van den - \ 2013
    Poultry Science 92 (2013)2. - ISSN 0032-5791 - p. 474 - 482.
    incubation-temperature - lipid-metabolism - chick-embryo - age - size - hens - hatchability - components - weight - growth
    Two experiments were conducted to study the interaction between breeder age and egg size on the energy utilization (experiment 1) and heat production (experiment 2) of broiler embryos. In experiment 1, a total of 4,800 Ross-308 hatching eggs from 2 breeder ages (29 and 53 wk of age, or young and old) and, within each age, 2 egg sizes (57 to 61 g and 66 to 70 g, or small and large) were used. In experiment 2, a total of 240 Ross-308 hatching eggs from 2 breeder flocks at 29 (young) and 53 (old) wk of age, and which were selected from the same egg weight range (58 to 61 g), were tested in 2 replicate chambers. In experiment 1, it was shown that the amount of yolk relative to albumen was higher in the old flock eggs, and this effect was more pronounced in the large eggs. The old flock eggs, especially the larger egg size, contained more energy as a result of a greater yolk size. Energy utilization of the embryos was positively related to yolk size and the amount of energy transferred to yolk-free body (YFB) was largely determined by the available egg energy. The efficiency of converting egg energy into chick body energy (EYFB) was equal for both egg sizes and both breeder age groups. Chick YFB weight of young and old flock eggs was equal. However, dry YFB weight of chicks from old flock eggs was higher than in chicks from young flock eggs, which was associated with more protein and fat content and thus more energy accumulated into YFB. As a consequence, embryos derived from old flock eggs produced more heat from d 16 of incubation onward than those of the young flock eggs. In conclusion, the higher energy deposition into chick YFB of old flock eggs, leading to higher embryonic heat production, is the result of a higher amount of available energy in the egg and is not due to changes in EYFB.
    Incubation temperature: A predisposing factor for ascites
    Molenaar, R. ; Hulet, R. ; Meijerhof, R. ; Maatjens, C.M. ; Kemp, B. ; Brand, H. van den - \ 2011
    Effect of eggshell temperature and oxygen concentration during incubation on the development and physiological status of broiler hatchlings in the perinatal period
    Molenaar, R. ; Anker, I. van den; Meijerhof, R. ; Kemp, B. ; Brand, H. van den - \ 2011
    Poultry Science 90 (2011)6. - ISSN 0032-5791 - p. 1257 - 1266.
    chick-embryo - thermal manipulations - nutrient utilization - gallus domesticus - organ growth - glycogen - performance - metabolism - heat - gluconeogenesis
    This study evaluated the influence of incubation conditions on the developmental and physiological status of birds in the perinatal period, which spans the end of incubation until the early posthatch period. Embryos were incubated at a normal (37.8°C) or high (38.9°C) eggshell temperature (EST) and a low (17%), normal (21%), or high (25%) O2 concentration from d 7 until 19 of incubation. After d 19 of incubation, EST was maintained, but O2 concentrations were 21% for all embryos. Body and organ weights, and hepatic glycogen levels were measured at d 18 of incubation and at 12 and 48 h after emergence from the eggshell. In addition, blood metabolites were measured at 12 and 48 h after emergence from the eggshell. Embryos incubated at a high EST and low O2 concentration had the highest mortality in the last week of incubation, which may be related to their low yolk-free body mass (YFBM) or a reduced nutrient availability for hatching (i.e., hepatic glycogen). High EST, compared with normal EST, decreased YFBM. This may be due to the shorter incubation duration of 8 h, the lower weight of supply organs (i.e., heart and lung), or a lack of glucose precursors. Because of this lack of glucose precursors, embryos incubated at high EST may have used proteins for energy production instead of for body development at the end of incubation. The YFBM at d 18 of incubation increased with an increase in O2 concentration. However, differences between the normal and high O2 concentration disappeared at 12 and 48 h after emergence, possibly because the high O2 concentration had difficulties adapting to lower O2 concentrations in the perinatal period. Blood metabolites and hepatic glycogen were comparable among O2 concentrations, indicating that the physiological status at hatch may be related to the environment that the embryo experienced during the hatching process. In conclusion, EST and O2 concentration differentially influence the developmental and physiological status of broilers during the perinatal period.
    High eggshell temperatures during incubation decrease growth performance and increase the incidence of ascites in broiler chickens
    Molenaar, R. ; Hulet, R. ; Meijerhof, R. ; Maatjens, C.M. ; Kemp, B. ; Brand, H. van den - \ 2011
    Poultry Science 90 (2011)3. - ISSN 0032-5791 - p. 624 - 632.
    pulmonary-hypertension syndrome - thermal manipulations - body-weight - environmental-temperature - embryo development - posthatch growth - poor ventilation - live performance - heat-production - egg size
    High eggshell temperatures (EST; 38.9°C) during the second half of incubation are known to decrease the body and organ development of broiler hatchlings. In particular, relative heart weights are decreased by a high EST, and this may increase the incidence of metabolic disorders that are associated with cardiovascular development, such as ascites. The current study investigated the effects of a high EST on chick quality, subsequent performance, and the incidence of ascites later in life. Eggs were incubated at a normal (37.8°C) or high (38.9°C) EST from d 7 of incubation onward. After hatching, the chickens were housed per EST in pens, and a normal or cold temperature schedule was applied during the grow-out period. Hatchability, hatchling quality, BW, feed conversion ratio, total mortality, mortality associated with ascites, slaughter characteristics, and ascites susceptibility at 6 wk of age were evaluated. Except for total ventricle weight, no interaction was found between EST and the grow-out temperature. Hatchability was comparable between the EST treatments, but the percentage of second-grade chickens was 0.7% higher at the high EST. Yolk-free body mass was 3.0 g lower, and heart weights were 26% lower at hatch in the high compared with the normal EST treatment. Body weight continued to be less during the grow-out period after the high EST incubation. However, breast meat yield was 1.0% higher in the high than in the normal EST. Feed conversion ratio did not differ between EST treatments. Total mortality was 4.1% higher and mortality associated with ascites was 3.8% higher in the high compared with the normal EST treatment. The ratio between the right and total ventricle was 1.1% higher in the high compared with the normal EST treatment at slaughter age. In conclusion, a high EST from d 7 of incubation onward decreased hatchling quality and growth performance, but increased breast meat yield. Furthermore, high EST incubation increased the incidence of ascites, which may be related to the reduced heart development at hatch.
    Energy partitioning during incubation and consequences for embryo temperature: A theoretical approach
    Lourens, A. ; Meijerhof, R. ; Kemp, B. ; Brand, H. van den - \ 2011
    Poultry Science 90 (2011). - ISSN 0032-5791 - p. 516 - 523.
    heat-production - eggshell temperature - lipid-metabolism - chick quality - egg size - broiler - growth - hatchability - consumption - exchange
    In practice, many hatchability and chick quality problems have been related to the control of embryo temperature (ET) during incubation. Within an incubator, set at a constant machine temperature (MT), ET can vary substantially. Embryo temperature is the result of the balance between heat transfer to and from the embryo and heat production (HP) of the embryo. We investigated which factors theoretically could account for the variation in ET within an incubator. First, the effects egg weight, MT, and oxygen availability on HP of embryos were quantified. Differences in HP could be due only to differences in the amount of energy utilized from the egg or to differences in the efficiency of the conversion of energy in the egg to energy in the chicken, indicated as EYFB. Results of these analyses showed that differences in HP attributable to egg weight or oxygen availability were mainly a result of the amount of energy used from the egg constituents and not of a change in EYFB. However, at a given MT, this variation in HP could account for a maximum increase in ET of only 1.21°C, suggesting that other factors played a role because in practice within an incubator, larger differences in ET have been found. The most important factor was probably the difference in air velocity within an incubator, resulting in differences in heat transfer. Because of this variation, ET varied within an incubator and with increasing ET, EYFB decreased, resulting in an even higher HP and consequently ET. We concluded that this theoretical approach could explain the wide variation in ET, and consequently could explain the negative effects of high ET on hatchability and chick quality found in the literature. This indicates that, in both practice and in incubation experiments, it is of great importance to realize that any factor affecting HP or heat transfer influences ET. We strongly suggest that ET (or eggshell temperature) be controlled in any incubation experiment involving hatchability or energy utilization.
    Perinatal development and nutrient utilization in chickens : effects of incubation conditions
    Molenaar, R. - \ 2010
    Wageningen University. Promotor(en): Bas Kemp, co-promotor(en): Henry van den Brand; R. Meijerhof. - S.l. : s.n. - ISBN 9789085858188 - 165
    vleeskuikens - eieren - embryonale ontwikkeling - embryologie - broeden - voedingsfysiologie - vleeskuikenresultaten - dierfysiologie - broilers - eggs - embryonic development - embryology - incubation - nutrition physiology - broiler performance - animal physiology
    Suboptimal incubation conditions can negatively affect survival and development of chicken embryos. However, physiological mechanisms that may explain these effects, and the long-lasting consequences are largely unknown. Therefore, the first aim of this thesis was to investigate effects of eggshell temperature (EST) and O2 availability during incubation on survival, development, physiology, and nutrient utilization of chicken embryos. The second aim was to investigate long-lasting effects of suboptimal EST on survival and subsequent performance of broiler chickens. The first study investigated effects of a high (38.9°C) or a normal (37.8°C) EST combined with a low (17%), normal (21%), or high (25%) O2 concentration from day 7 until 19 of incubation on the survival rate, nutrient utilization, and the developmental and physiological status of broiler embryos. The second study investigated effects of high EST on glucose metabolism in broiler embryos using [U-13C]glucose. The third study investigated effects of high EST on growth performance and the incidence of ascites in broiler chickens. Finally, effects of a high EST and a hole in the air cell on the developmental and physiological status of layer hatchlings were investigated. Results showed that a high EST or low O2 availability from the first week of incubation onward negatively affected survival and development of broiler chickens from their perinatal period until slaughter age. Body development of broiler hatchlings was reduced after high EST incubation because of a lower efficiency in protein utilization for growth. This was possibly due to the use of glucogenic amino acids as a glucogenic energy source, because high EST increased the glucose oxidation in broiler embryos during the second half of incubation and resulted in lower hepatic glycogen. Body development was proportional to the O2 availability during incubation. In addition, differences in O2 concentration during incubation seem to affect the development of adaptive mechanisms, and these mechanisms might possible influence nutrient utilization and body development. High EST in the last week of incubation in layer embryos negatively affected hatchling development, but the effect of a hole in the air cell was minimal. Effects of high EST were long-lasting in broiler chickens expressed by a lower body weight and a higher ascites incidence during the growout period. In conclusion, negative effects of suboptimal incubation conditions can be partly explained by changes in nutrient utilization and metabolite levels in the perinatal period and can have long-lasting effects on the survival and performance of broiler chickens.
    Check title to add to marked list
    << previous | next >>

    Show 20 50 100 records per page

     
    Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.