| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
EDITORIAL |
One of the pleasures of being editor-in-chief is that I read every paper published in the journal. From time to time, issues of concern arise and today I am addressing several. The essential principles throughout science require that experiments have a sound theoretical basis, be well designed to test a hypothesis, be analyzed using appropriate statistics, and be repeatable. A corollary to the latter point is that data should be comparable from study to study and from laboratory to laboratory. This allows for meta- and holo-analyses. One of the chemical analyses that would appear to be trivial yet fundamental is determination of blood, plasma, and serum glucose. Where are we as a discipline in such a simple determination as that of glucose?
The concentration of glucose in chickens is reported as the range 190 to 220 mg/dL (reviewed by Hazelwood, 1986). Chickens are very hyperglycemic and insulin-resistant compared with mammals. This situation applies to turkeys but less to ducks and geese. However, there is considerable variation in the steady-state circulating glucose concentration in recent reports even for similarly aged fed chickens (average in 15 studies = 234 ± 11.8 (SEM) mg/dL, ranging between 156 and 330 mg/dL in young meat lines; see Table 1
). Between studies, there is no obvious effect of age or method determination of glucose but the magnitude of the variation is of concern. The intraassay variation is presumed to be small based on the low coefficient of variation between samples from different birds reported at the same time point. Obviously, interassay and interlaboratory variation may be high or there may be an underlying but undiscovered biological basis. Perhaps there should be a requirement by journals for authors to provide data on intra- and interassay variance using a chicken plasma/serum pool. This is particularly pertinent when using clinical laboratory services for chemical analysis. Moreover, it might be questioned if should be an international "standard" for chicken glucose determination and for other metabolites and hormones. This standard could be a pool of chicken plasma available to all investigators commercially or through a cooperative program between investigators. This would combat the lack of standardization of techniques and be a service to the industry, and particularly pathology laboratories.
|
The literature suggests that starvation has relatively little effect on circulating concentrations of glucose. In earlier studies, not using modern meat-type chickens, starvation did not affect circulating concentrations of glucose in some studies (Hazelwood and Lorenz, 1959; Belo et al., 1976; Tinker et al., 1986) but did in others (Harvey et al., 1978). However, there are consistently decreases, albeit relatively small, in circulating concentrations of glucose following short-term starvation reported for meat-type birds (e.g., Edwards et al., 1999; Buyse et al., 2002; Nijdam et al., 2006).
These data again show a lack of clear consistency. This editorial attempts to challenge investigators as to what can and should be done to address this and related issues.
 |
REFERENCES |
|---|
 TOP REFERENCES |
|---|
Ashwell, C. M., and J. P. McMurtry. 2003. Hypoglycemia and reduced feed intake in broiler chickens treated with met-formin. Poult. Sci. 82:106–110.
Belo, P. S., D. R. Romsos, and G. A. Leveille. 1976. Blood metabolites and glucose metabolism in the fed and fasted chicken. J. Nutr. 106:1135–1143.
Buyse, J., K. Janssens, S. Van der Geyten, P. Van As, E. Decuypere, and V. M. Darras. 2002. Pre- and postprandial changes in plasma hormone and metabolite levels and hepatic deiodinase activities in meal-fed broiler chickens. Br. J. Nutr. 88:641–653.[CrossRef][Web of Science][Medline]
Corzo, A., E. T. Moran, D. Hoehler, and A. Lemmell. 2005.Dietary tryptophan need of broiler males from forty-two to fifty-six days of age. Poult. Sci. 84:226–231.
Crespo, N., and E. Esteve-Garcia. 2003. Polyunsaturated fatty acids reduce insulin and very low density lipoprotein levels in broiler chickens. Poult. Sci. 82:1134–1139.
Edwards, M. R., J. P. McMurtry, and R. Vasilatos-Younken. 1999. Relative insensitivity of avian skeletal muscle glycogen to nutritive status. Domest. Anim. Endocrinol. 16:239–247.[CrossRef][Web of Science][Medline]
Harvey, S., C. G. Scanes, A. Chadwick, and N. J. Bolton. 1978.Influence of fasting, glucose and insulin on the levels of growth hormone and prolactin in the plasma of the domestic fowl (Gallus domesticus). J. Endocrinol. 76:501–506.
Hazelwood, R. L. 1986. Carbohydrate metabolism. Pages 303–325 in Avian Physiology. P. D. Sturkie, ed. Springer Verlag, New York, NY.
Hazelwood, R. L., and F. W. Lorenz. 1959. Effects of fasting and insulin on carbohydrate metabolism of the domestic fowl. Am. J. Physiol. 197:47–51.
Lin, H., S. J. Sui, H. C. Jiao, K. J. Jiang, J. P. Zhao, and H. Dong. 2007. Effects of diet and stress mimicked by corticosterone administration on early postmortem muscle metabolism of broiler chickens. Poult. Sci. 86:545–554.
Lu, J. W., J. P. McMurtry, and C. N. Coon. 2007. Developmental changes of plasma insulin, glucagon, insulin-like growth factors, thyroid hormones, and glucose concentrations in chick embryos and hatched chicks. Poult. Sci. 86:673–683.
Metayer, S., S. Tesseraud, S. Cassy, M. Taouis, J. Williams, M. Picard, and N. Rideau. 2006. Is there peripheral or ovarian insulin action alteration in broiler breeder hens fed ad libitum? Poult. Sci. 85:1098–1103.
Mumma, J. O., J. P. Thaxton, Y. Vizzier-Thaxton, and W. L. Dodson. 2006. Physiological stress in laying hens. Poult. Sci. 85:761–769.
Myers, M. R., and K. C. Klasing. 1999. Low glucokinase activity and high rates of gluconeogenesis contribute to hyperglycemia in barn owls (Tyto alba) after a glucose challenge. J. Nutr. 129:1896–1904.
Nijdam, E., E. Lambooij, M. J. A. Nabuurs, E. Decuypere, and J. A. Stegeman. 2006. Influences of feeding conventional and semisynthetic diets and transport of broilers on weight gain, digestive tract mass, and plasma hormone and metabolite concentrations. Poult. Sci. 85:1652–1659.
Pal, L., R. Grossmann, K. Dublecz, F. Husveth, L. Wagner, A. Bartos, and G. Kovacs. 2002. Effects of glucagon and insulin on plasma glucose, triglyceride, and triglyceride-rich lipoprotein concentrations in laying hens fed diets containing different types of fats . Poult. Sci. 81:1694–1702.
Peebles, E. D., J. D. Cheaney, J. D. Brake, C. R. Boyle, and M. A. Latour. 1997b. Effects of added dietary lard on bodyweight and serum glucose and low density lipoprotein cholesterol in randombred broiler chickens. Poult. Sci. 76:29–36.
Peebles, E. D., R. W. Keirs, L. W. Bennett, T. S. Cummings, S. K. Whitmarsh, and P. D. Gerard. 2005. Relationships among prehatch and posthatch physiological parameters in early nutrient restricted broilers hatched from eggs laid by young breeder hens . Poult. Sci. 84:454–461.
Peebles, E. D., A. L. Pond, J. R. Thompson, C. D. McDaniel, N. M. Cox, and M. A. Latour. 1997a. Naloxone attenuates serum corticosterone and augments serum glucose concentrations in broilers stimulated with adrenocorticotropin. Poult. Sci. 76:511–515.
Savenije, B., E. Lambooij, M. A. Gerritzen, K. Venema, and J. Korf. 2002. Effects of feed deprivation and transport on preslaughter blood metabolites, early postmortem muscle metabolites, and meat quality. Poult. Sci. 81:699–708.
Shapiro, F., M. Mahagna, and I. Nir. 1997. Stunting syndrome in broilers: Effect of glucose or maltose supplementation on digestive organs, intestinal disaccharidases, and some blood metabolites. Poult. Sci. 76:369–380.
Sinsigalli, N. A., J. P. McMurtry, J. A. Cherry, and P. B. Siegel. 1987. Glucose tolerance, plasma insulin and immu-noreactive glucagon in chickens selected for high and low body weight. J. Nutr. 117:941–947.
Thaxton, J. P., W. A. Dozier, S. L. Branton, G. W. Morgan, D. W. Miles, W. B. Roush, B. D. Lott, and Y. Vizzier-Thaxton. 2006. Stocking density and physiological adaptive responses of broilers. Poult. Sci. 85:819–824.
Tinker, D. A., J. T. Brosnan, and G. R. Herzberg. 1986. Interorgan metabolism of amino acids, glucose, lactate, glycerol and uric acid in the domestic fowl (Gallus domesticus). Biochem. J. 240:829–836.[Web of Science][Medline]
Zhan, X. A., M. Wang, H. Ren, R. Q. Zhao, J. X. Li, and Z.L. Tan. 2007. Effect of early feed restriction on metabolic programming and compensatory growth in broiler chickens. Poult. Sci. 86:654–660.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
