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ABSTRACT: 1. The aim of this study was to investigate if genetic predisposition to ascites interacts with changed incubation conditions, and how this might affect the post-hatch performance and ascites susceptibility. 2. An ascites sensitive (A) and resistant (E) broiler line were incubated under standard or high CO(2) conditions (up to 4%) from embryonic d 10 onwards. After hatch, chicks were exposed to cold from the 15th day of the rearing period to increase the incidence of ascites. 3. The A line had a higher post-hatch body weight from week three, higher blood pCO(2) from d 21, higher haematocrit at d 35 and d 42, and higher plasma corticosterone concentration from d 21 onwards, compared with the E line, regardless of incubation conditions, supporting the given selection criteria. Ascites mortality did not, however, differ between lines. 4. Incubation under high CO(2) conditions during the second half of incubation increased the ascites mortality, decreased body weight from week 4 onwards, affected venous blood pCO(2), decreased blood pO(2) from d 31, increased haematocrit at d 35 and d 42, and lowered the thyroxine and triiodothyronine concentrations at most sampling days. These effects were observed in both lines. The results suggested a metabolic programming of CO(2) incubated chickens which affected ascites susceptibility.
British Poultry Science 04/2012; 53(2):262-9. · 1.00 Impact Factor
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Communications in agricultural and applied biological sciences 01/2012; 77(1):269-73.
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ABSTRACT: Heat stress is known to impair performance and to induce oxidative stress in poultry. The aim of the present study was to compare the effects of dietary supplementation of dl-methionine (dl-M) or the synthetic analog 2-hydroxy-4-methylthiobutanoic acid (dl-HMTBA) on broiler growth performance, plasma hormone levels, and some oxidative stress-related parameters under conditions of chronic exposure to high temperatures (HT). From 2 to 6 wk of age, male broiler chickens were reared under either a constant temperature of 32°C until 6 wk of age or a normal temperature scheme (gradual decrease to 18°C at 5 wk of age). Chicks in both the normal and HT treatments were provided with a commercial grower diet supplemented with either 1.0 or 1.2 g/kg of dl-M or 1.0 or 1.2 g/kg of dl-HMTBA. Because there were no effects of supplement dose, data were pooled over both doses within each temperature treatment. The chronic HT treatment impaired feed intake and BW gain, but these negative effects were less pronounced when the chickens received dl-HMTBA. Exposure to HT was also associated with decreased (P < 0.001) plasma thyroid hormones and increased (P < 0.0001) plasma corticosterone levels. At 4 wk of age, and irrespective of the supplemental source, chickens subjected to HT were characterized by significantly lower plasma TBA-reactive substance levels. In contrast, at 6 wk of age, plasma TBA-reactive substance levels were significantly increased by HT, but this effect was observed only for the chickens receiving dl-M and not for those receiving dl-HMTBA. High temperatures induced a significant increase in hepatic total glutathione (GSH) and oxidized GSH levels, regardless of the supplemental source. However, the hepatic ratios of reduced GSH to total GSH and reduced GSH to oxidized GSH were highest in chickens supplemented with dl-HMTBA. In conclusion, dl-HMTBA supplementation partially prevented the growth-depressing effects of chronic heat exposure compared with dl-M supplementation. It can be inferred that dl-HMTBA is more efficient in alleviating HT-induced oxidative damage because of a more favorable reduced GSH-to-total GSH ratio.
Poultry Science 10/2011; 90(10):2311-20. · 1.73 Impact Factor
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ABSTRACT: Intermittent high (+3°C) and low (-3°C) temperature treatments for 4 h on embryonic day (E) 16, E17, and E18 showed differential effects on embryonic metabolism, without influencing embryonic growth or hatchability. Embryos in the high-temperature group shifted to a more anaerobic metabolism, as indicated by a lower partial pressure of O(2) and a higher partial pressure of CO(2) in the air cell, lower blood pH, and higher lactic acid production. Three hours after the end of the high-temperature treatment, a decrease in metabolism was observed, as indicated by the lower partial pressure of CO(2) and higher partial pressure of O(2) in the air cell and increased plasma triglyceride levels. The embryos in the low-temperature group responded by temporarily slowing down their metabolism, especially the metabolism of carbohydrates and lipids, as indicated by altered air cell gases, a higher relative yolk weight, higher plasma triglyceride level, and higher liver glycogen level. Three hours after the end of the temperature treatment, the metabolism of embryos in the low-temperature treatment had increased to the level of the control temperature group. However, for both temperature treatments, during the hatching process, all the shortages and excesses created were restored to control levels, which would explain the lack of change in embryo growth and hatchability and the slight delay in the hatching process. These mild consequences of the intermittent temperature treatment indicate that the different metabolic shifts made by the embryos seem to be efficient in overcoming the challenges of the intermittent high- or low-temperature treatment during late incubation.
Poultry Science 06/2011; 90(6):1302-12. · 1.73 Impact Factor
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The Journal of Agricultural Science 05/2011; 149(03):369 - 384. · 2.04 Impact Factor
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ABSTRACT: During avian embryonic development, the carbon dioxide tension inside the egg increases as the shell restricts gas exchange with the environment. Acid-base regulation of the avian embryo is a complex process, not only due to the non-function of the lungs and limited functionality of the kidneys but also because the embryo is affected by the inflow of bicarbonates from the shell, when calcium is reabsorbed for calcification. Moreover, interaction occurs between the embryo and the extraembryonic compartments. It has been shown that carbonic anhydrase plays a crucial role in the formation of sub-embryonic fluid and in the chorioallantoic membrane and kidney. This review provides a detailed overview of the acid-base status of the extraembryonic compartments inside chicken eggs, and their interaction in keeping the acid-base status of the embryo balanced. Secondly, experimental acid-base disturbances are summarized. The last part of the review briefly compares embryos of birds and other amniotes (mammals and reptiles) with regard to acid-base regulation.
Respiratory Physiology & Neurobiology 05/2011; 178(1):118-28. · 2.24 Impact Factor
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ABSTRACT: Temperatures continuously higher and lower than the standard incubation temperature by 3°C from embryonic d 16 until embryonic d 18.5 result in differential effects on embryonic development, the hatching process, and embryonic metabolism. Embryos in the high-temperature group were forced into a state of malnutrition by the temperature treatment, as reflected by reduced embryo growth and yolk consumption, resulting in a significantly lower chick weight at hatch. In addition, altered air cell and blood gases as well as a retarded hatching process further indicated reduced growth of embryos exposed to higher incubation temperatures during the latter part of incubation. In addition, hatchability was significantly reduced by the high-temperature treatment due to higher embryonic mortality during the treatment period and the hatching process. Levels of blood glucose, lactate, liver glycogen, plasma triglycerides, and nonesterified fatty acids indicated an altered carbohydrate and lipid metabolism for the high-temperature group. Although the hatching process of embryos exposed to lower incubation temperatures was also significantly retarded, their embryonic development and growth were strikingly similar to those of the control group.
Poultry Science 12/2010; 89(12):2678-90. · 1.73 Impact Factor
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ABSTRACT: A QTL located in the paternally expressed insulin-like growth factor 2 (IGF2) gene is known to increase muscle growth and reduce fat deposition in pigs. This makes the QTL in IGF2 a good marker for use in pig breeding programmes. However, care has to be taken as it is postulated that increased leanness and lowered fat deposition may have a negative effect on the prolificacy and longevity of sows. Selection of sire and dam lines for different alleles of the mutation in the paternally imprinted IGF2 gene could actually provide a solution to this problem. Therefore, in this study, the effect of the IGF2 QTL on prolificacy-related traits in sows was investigated. It was found that the paternal IGF2 wild-type allele was associated with higher reproduction performance in the sow. Moreover, it was also examined whether the difference in prolificacy in sows could be a consequence of differential IGF2 expression in the ovarian follicles of the sow or whether it is mainly a secondary effect caused by differences in fatness traits. Therefore, IGF2 expression was measured in follicles of different sizes from sows with different genotypes for the paternal IGF2 allele. It was observed that, however, while the size of the follicles was associated with follicular IGF2 expression level, the IGF2 genotype was not. It could be concluded that the difference in prolificacy of sows with a different paternal IGF2 genotype could be a secondary effect, resulting from differences in fat deposition.
Animal Genetics 10/2010; 41(5):493-8. · 2.40 Impact Factor
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ABSTRACT: 1. Due to intensive selection, broiler chickens became the most efficient meat-producing animals because of their fast growth, supported by a virtually unlimited voluntary feed intake. These characteristics cause many problems in the management of broiler breeder hens because of the negative correlation between muscle growth and reproduction effectiveness. 2. This problem, namely the fast muscle growth versus reproduction health paradox, induces a second paradox, acceptable reproduction and health versus hunger stress and impaired welfare, because broiler breeder hens require dedicated programmes of feed restriction (1) to maximise egg and chick production and (2) to avoid metabolic disorders and mortality in broiler breeders. 3. Given that poultry selection is a global large-scale business and chickens are a prolific species, improvement in profit can only be obtained by selecting on feed conversion and/or for higher breast meat percentage, which will intensify the broiler-breeder paradox. 4. New feeding strategies are being studied, but it is questionable if the paradox can be solved by management tools alone. Because breeding and selection are long-term processes, involving animals, farmers, consumers, industry, environment etc., a more sustainable breeding goal needs to be determined by a multidisciplinary approach and an open debate between several actors in the discussion. 5. Using dwarf broiler breeder hens could be one alternative, because dwarf hens combine relatively good reproductive fitness with ad libitum feeding. Another possibility is to accept lower broiler productivity by assigning economic values to welfare and including integrity traits in an extended breeding goal.
British Poultry Science 10/2010; 51(5):569-79. · 1.00 Impact Factor
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ABSTRACT: Broiler performance is known to be related to embryonic developmental parameters. However, strain or genotype differences with regard to embryo physiological parameters and juvenile growth have received little attention. A total of 1,200 hatching eggs produced by Cobb and Ross broiler breeders of the same age were studied. At setting for incubation and between 66 and 130 h of incubation, egg resonant frequency (RF) was measured as an indicator of embryonic development. Also, eggs were weighed before setting and at d 18. From d 10 to 18 of incubation, remaining albumen was weighed. During the last days of incubation, hatching events such as internal pipping (IP), external pipping, and hatch were monitored every 2 h. Hatched chicks were recorded and weighed. At IP stage, gas partial pressures in the egg air chamber were measured. Hatched chicks were reared for 7 d and weighed. Results indicate that RF of Ross eggs were lower than those of Cobb eggs (P < 0.01) and starting time point of RF decrease occurred earlier in Cobb eggs than in Ross eggs. Relative egg weight loss up to 18 d of incubation was lower in Cobb than in Ross (P < 0.05). At IP, partial pressure of CO(2) was higher in Cobb than in Ross (P < 0.05) with shorter incubation duration in Cobb. Between 6 and 60 h posthatch, heat production was higher in Cobb than in Ross (P < 0.05). At 7 d posthatch, Cobb chicks were heavier than Ross chicks (P < 0.05). It is concluded that Cobb and Ross embryos-chicks have different growth trajectories leading in different patterns of growth resulting from differences in physiological parameters.
Poultry Science 08/2010; 89(8):1677-83. · 1.73 Impact Factor
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ABSTRACT: Ascites syndrome is a metabolic disorder found in modern broilers that have insufficient pulmonary vascular capacity. Commercial breeding programs have heavily focused on high growth rate, which led to fast-growing chickens, but as a negative consequence, the incidence of ascites syndrome increased. However, not all birds with a high growth rate will suffer from ascites syndrome, which might indicate a genetic susceptibility to ascites. Information on blood gas parameters measured early in life and their relation to ascites susceptibility is expected to contribute to identification on the cause of ascites syndrome. In this study, several physiological parameters, such as blood gas parameters [pH, partial pressure of CO(2) in venous blood (pvCO(2)), and partial pressure of O(2) in venous blood], hematocrit, electrolytes (Na(+), Ca(2+), and K(+)), metabolites (lactate and glucose), were measured at d 11 to 12 of age from 100 female and 100 male broilers. From d 14 onward, the birds were challenged to provoke the development of ascites syndrome. Our results showed that high pvCO(2) values together with low pH values (males) or high pH values (females) in the venous blood of juvenile broilers coincided with ascites. Therefore, blood pvCO(2) and pH in both juvenile male and female broilers seem to be critical factors in ascites pathophysiology and can be used as phenotypic traits to predict ascites susceptibility in juvenile broilers at d 11 to 12. A prediction model was built on a subpopulation of the broilers without any loss in sensitivity (0.52) and specificity (0.78) when applied to the validation population. The parameter sex was included in the prediction model because levels of pvCO(2) and pH that associated with ascites susceptibility are different between males and females. Commercial breeders can include these phenotypic traits in their genetic selection programs to reduce the incidence of ascites syndrome.
Poultry Science 08/2010; 89(8):1684-91. · 1.73 Impact Factor
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ABSTRACT: The importance of carbonic anhydrase (CA) during exposure of chicken embryos to CO(2) during the second half of incubation was investigated. The protein abundance and activity of CAII in erythrocytes was significantly higher in CO(2)-exposed embryos compared to normal conditions. Daily injections of acetazolamide (ATZ), an inhibitor of CA, increased blood P(CO2) and decreased blood pH in both control and CO(2)-incubated embryos. ATZ increased blood bicarbonate concentration in embryos exposed to normal atmosphere and in day-12 embryos exposed to high CO(2). The tendency of an increased blood potassium concentration in ATZ-injected embryos under standard atmospheric conditions might indicate that protons were exchanged with intracellular potassium. However, there was no evidence for such an exchange in CO(2)-incubated ATZ-treated embryos. This study shows for the first time that chicken embryos adapt to CO(2) during the second half of incubation by increasing CAII protein expression and function in red blood cells. This response may serve to "buffer" elevated CO(2) levels.
Respiratory Physiology & Neurobiology 07/2010; 172(3):154-61. · 2.24 Impact Factor
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ABSTRACT: 1. Because CO(2) during the second half of incubation is known to influence air cell and blood gases, and embryo development, it is postulated that post-hatch development and ascites sensitivity could also be influenced. 2. An ascites susceptible (A) and an ascites resistant (E) broiler line were incubated under standard incubation or high CO(2) conditions (up to 4%) from embryonic day (ED) 10 onwards. The embryonic development and the hatching process of these two lines were compared when incubated under standard or high CO(2) conditions from over the second half of incubation. 3. The A line, selected for high post-hatch growth rate, exhibited a higher relative embryo weight from ED10 until ED16, which was supported by a higher air cell pCO(2), lower air cell pO(2), higher corticosterone and thyroid hormones and earlier hatching time. 4. Incubation under high CO(2) increased air cell pCO(2), retarded yolk consumption, and decreased glycogen concentration in the liver at hatch. Hatchability decreased in both lines when incubated under high CO(2), due to an increased late mortality of embryos that died before IP. 5. These results suggest that the development and metabolism of CO(2)-incubated embryos differ from control incubated embryos.
British Poultry Science 06/2010; 51(3):335-43. · 1.00 Impact Factor
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ABSTRACT: In a commercial hatchery, chicks (or poults) hatch over a 24-48 hour period. All chicks remain in the incubator until the majority of the chicks have emerged from the shell. Once removed from the incubator, the newly hatched chick has to undergo several hatchery treatments and is then transported before being placed on the broiler farm. This means that, under practical conditions, chicks are deprived of feed and water for up to 72 hours. In addition, the time of hatch within the hatching window and the spread of hatch cause variability in the amount of time that chicks are feed deprived. Literature on feed deprivation after hatch clearly demonstrates the detrimental effects of any delay in feed access on performance of the chicks with respect to growth, immune system activation, digestive enzyme stimulation and organ development. Improved management strategies, such as shortening the hatching window or the time to first feeding by specific management measures, provide an alternative in dealing with the negative effects caused by a delay in feed access. The development of pre-starter diets that better meet the needs of the newly hatched chicks or in ovo feeding to bridge the gap between hatch and first feeding provide other alternatives in overcoming these problems. However, speculation remains regarding the importance of in ovo or early feeding, or whether the in ovo or early feeding itself is responsible for the beneficial effects reported. The aim of the following review is to discuss the current status of research into early feeding and to stimulate future and further research regarding these topics.
World's Poultry Science Journal 05/2010; 66(02):177 - 188.
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K Mertens,
I Vaesen,
J Loffel,
B Kemps,
B Kamers,
C Perianu,
J Zoons,
P Darius, E Decuypere,
J De Baerdemaeker,
B De Ketelaere
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ABSTRACT: Stress and diseases have the potential to influence the deposition of eggshell pigmentation during egg formation. Therefore, defining the shell color of eggs on a daily basis could be a representative method for monitoring stress or health status of a flock and maintaining good performance. A novel way of measuring eggshell color based on visible-near infrared transmission spectroscopy transmission spectra was defined: the transmission color value (TCV). The TCV was calculated as the ratio between the transmission at 643 nm (maximum absorbance of the pigmentation molecule protoporphyrin IX) and the transmission at 610 nm (a reference wavelength). Experiments were carried out to investigate the relevance of TCV for monitoring flock stress and health or even anticipating any factors unfavorable to performance. In 2 small experimental flocks, deliberate heat stress challenges were applied. A medium-scale experimental flock in an aviary was monitored on a daily basis during the whole productive period. From the deliberate heat stress challenges, it was seen that stress had a significant effect on eggshell pigmentation. This observation was confirmed in a daily monitored flock, in which, for example, an infectious bronchitis infection occurred. These stress situations were quickly reflected by an increased TCV value: more transmission due to less pigmentation and hence less absorbance at the pigmentation wavelength. Furthermore, for the observed problems in the daily monitoring, the TCV value signaled the problem earlier (4 d) than the average egg weight or even signaled when the other parameters did not signal anything. Measuring the TCV of all eggs produced on a daily basis provides relevant information on the stress or health status of a flock of brown layers. This could be used as an early detection of stress situations or emerging diseases, even before important quality and health damage can occur.
Poultry Science 03/2010; 89(3):609-17. · 1.73 Impact Factor
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ABSTRACT: The aim of this study was to investigate the influence of isoenergetic substitution between the three energy delivering macronutrients in pre-starter diets on performance and intermediary nutrient metabolism in broiler chickens. From hatch until 5 days of age, 600 chicks, collected during peak of hatch, were fed one of the three experimental pre-starter diets with isoenergetic (13 MJ metabolisable energy/kg) substitutions between fat (43 vs. 108 g/kg), protein (126 vs. 240 g/kg) and carbohydrates (391 vs. 510 g/kg). After 5 days, commercial grower and finisher diets were provided. Pre-starter composition influenced body weight until slaughter age, although not statistically verifiable. Broilers fed the low protein (LP) pre-starter had the lowest body weight in relation to chickens on the low carbohydrate or low fat pre-starter diet. After hatch, chicks on the LP pre-starter diet were able to use the residual yolk sac more rapidly to fulfil their protein requirement, which is reflected in small intestine and liver development. Also, plasma metabolite levels were influenced mostly by the LP pre-starter, indicating that the main focus for the requirements of newly hatched chicks should be on proteins. Furthermore, optimal nutrition during the first day's post-hatch should take into account the contribution of the yolk.
J Anim Physiol a Anim Nutr 11/2009; 94(3):375-84. · 0.86 Impact Factor
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ABSTRACT: The objective of the present experiment was to study the effects of parental age and heat acclimation of embryos on blood metabolites and hormones of broilers exposed to daily cyclic ambient temperatures from d 21 to 42. Eggs obtained from 32 (younger), 42 (middle-aged), and 65 wk (older) breeders were divided into 2 groups. One group of eggs was incubated at control incubation temperature (ITCONT), whereas the second group was heat-acclimated at 38.5 degrees C for 6 h/d from d 10 to 18 of incubation (ITHA). Chicks were reared at standard brooding temperatures from 1 to 21 d. From d 21 to 42, half of broilers/incubation temperature/parental age was kept as the control (ATCONT), whereas the other half was exposed to daily cyclic heat treatment (ATHIGH) to impose a stress response. There was a reduction in plasma triiodothyronine (T3) levels in ITHA broilers. On d 28, plasma T3 levels were similar regardless of parental age of eggs incubated at ITCONT, whereas ITHA resulted in lower levels of T3 in broilers from 65 wk parents. At the same age, ATHIGH reduced plasma triglycerides with the effect greater for ITHA than ITCONT broilers. Plasma uric acid was also lower for ITHA than ITCONT broilers for the offspring of 65 wk parents on d 28. There was an increase in plasma creatine kinase activity on d 42 in ATHIGH broilers regardless of parental age and incubation temperature. Plasma corticosterone was consistently lower for the ITHA than ITCONT treatment, being significant on d 21 and 42. It was concluded that these changes in blood metabolites and hormones may enhance the thermoregulatory ability of ITHA broilers when exposed posthatch to daily high temperatures.
Poultry Science 10/2009; 88(9):2006-13. · 1.73 Impact Factor
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ABSTRACT: The objective of this study was to investigate the effects of diet composition on performance, slaughter yield and plasma metabolites, as different modern broiler strains show different responses to feed intake. Broilers of two commercial strains and of both sexes received one of three diets being different in energy and/or protein level [control diet, low energy/low protein diet (LM/LP) and low protein diet (LP)]. Low energy/low protein diet chickens were characterized by significantly lower body weights and feed intake compared with their LP and control counterparts. Broilers of the Cobb strain or broilers that were fed the control diet were most efficient in converting energy to body weight. No significant differences in plasma metabolites were detected due to diet composition or genotype. The diet with the lower energy and crude protein levels reached the lowest slaughter yield but the highest drumstick and wing percentages. The lowest mortality percentages were observed for broilers fed the LM/LP diet, and Cobb birds appeared to be more sensitive for metabolic disorders resulting in death. It is obvious from this study that different genotypes respond differently to changes in diet composition and therefore have adjusted nutritional requirements.
J Anim Physiol a Anim Nutr 09/2009; 94(4):509-18. · 0.86 Impact Factor
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R Joubert,
S Métayer Coustard,
Q Swennen,
V Sibut,
S Crochet,
E Cailleau-Audouin,
J Buyse, E Decuypere,
C Wrutniak-Cabello,
G Cabello,
S Tesseraud,
A Collin
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ABSTRACT: Avian uncoupling protein (avUCP) is orthologous to UCP3, which is suggested to be involved in fatty acid metabolism and to limit the mitochondrial production of reactive oxygen species in mammals. In the chicken, the role and regulation of avUCP remain to be clarified. The aim of this study was to explore the control of avUCP expression by the beta-adrenergic system, known to be involved in avian thermoregulation and lipid utilization, and in UCP expression in mammals. Therefore, we measured the expression of avUCP mRNA and protein in the Pectoralis major muscle of chickens injected with the beta(2) agonist isoproterenol, and we investigated the potential pathways involved in the regulation of avUCP mRNA expression. Avian UCP mRNA expression was increased 7-fold 4h after isoproterenol injection, leading to a tendency to a 40% increase in avUCP protein 24h post-injection. This increase was preceded, 30 min after isoproterenol injection, by changes in the chicken thyroid status and in the muscular expression of PPARalpha, PPARbeta/delta, and PPARgamma coactivator-1alpha (PGC-1alpha). Moreover, the analysis of the avUCP promoter sequence suggested potential binding sites for PPARs and for thyroid hormone receptors. We also detected the activation of AMP-activated protein kinase, which has recently been reported to be involved in UCP3 regulation in mammals. This study presents for the first time evidence of beta-adrenergic control on avUCP messenger expression in chicken muscle and suggests the potential involvement of AMPK and several transcription factors in this regulation.
Domestic animal endocrinology 09/2009; 38(2):115-25. · 1.65 Impact Factor
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ABSTRACT: Cholecystokinin (CCK) is known to have a short biological half-life. In order to prolong the half-life and create a new investigative tool, we previously PEGylated the peptide, yielding PEG-CCK(9), and demonstrated that it had a dose-dependent prolonged anorectic effect. The aim of this study was to investigate whether PEG-CCK(9) reduces food intake by inducing satiation or by abnormal physiological effects, such as pain, malaise, or nausea. An observational study was performed to examine the effects of different doses of PEG-CCK(9) (1, 2, 4, 8, or 16 microg kg(-1)) on feeding and other behaviors. The behavioral sequence associated with satiety (BSS), i.e. the orderly progression from eating, through grooming and activity, to resting, was analyzed. From the lowest dose tested (1 microg kg(-1)), PEG-CCK(9) caused a dose-dependent reduction in food intake due to a dose-related reduction in both the duration and frequency of eating and a dose-dependent increase in duration of rest. A dose-dependent acceleration in the temporal profile of the BSS was observed, while the normal structure of feeding behaviors was well preserved, except at the dose of 16 microg kg(-1) of PEG-CCK(9), at which a decrease in eating rate and grooming behavior was observed, together with the occurrence of a significant number of abdominal cramps. These findings suggest that the hypophagic response to PEG-CCK(9) is mainly induced by natural mechanisms of satiety, although abnormal physiological effects, such as abdominal cramps, might reinforce the food inhibitory effect, especially at high doses of PEG-CCK(9) (>8 microg kg(-1)).
Physiology & Behavior 05/2009; 98(1-2):198-204. · 2.87 Impact Factor
