An extended model of phosphorus metabolism in growing ruminants1
| العنوان: | An extended model of phosphorus metabolism in growing ruminants1 |
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| المؤلفون: | R. S. Dias, S. López, R. M. P. Patiño, T. S. Silva, J. C. Silva Filho, D. M. S. S. Vitti, M. R. S. R. Peçanha, E. Kebreab, J. France |
| المصدر: | Journal of Animal Science. 89:4151-4162 |
| بيانات النشر: | Oxford University Press (OUP), 2011. |
| سنة النشر: | 2011 |
| مصطلحات موضوعية: | medicine.medical_specialty, Saliva, Phosphorus, chemistry.chemical_element, General Medicine, Metabolism, Biology, Resorption, Phosphorus metabolism, Excretion, Rumen, Endocrinology, chemistry, Internal medicine, Genetics, medicine, Animal Science and Zoology, Feces, Food Science |
| الوصف: | A major objective of this study was to extend the Vitti-Dias model used to describe P metabolism in ruminants, by adding 2 new pools to the original model to represent the rumen and saliva. An experiment was carried out using 24 male sheep, initial BW of 34.5 kg, aged 8 mo, fed a basal diet supplied with increasing amounts of dicalcium phosphate to provide 0.14, 0.32, 0.49, and 0.65% P in the diet. Sheep were individually housed indoors in metabolic cages and injected with a single dose of 7.4 MBq of (32)P into a jugular vein. Feed intake and total fecal and urinary outputs were recorded and sampled daily for 1 wk, and blood samples were obtained at 5 min, and 1, 2, 4, 6, 24, 48, 72, 96, 120, 144, and 168 h after (32)P injection. Saliva and rumen fluid samples were taken on d 6, 7, and 8. Then, animals were slaughtered and samples from liver, kidney, testicle, muscle, and heart (soft tissue) and bone were collected. Specific radioactivity and inorganic P were then determined in bone, soft tissue, plasma, rumen, saliva, and feces, and used to calculate flows between pools. Increased P intake positively affected total P (r = 0.97, P < 0.01) and endogenous P excretion in feces (r = 0.85, P < 0.01), P flow from plasma to saliva (r = 0.73, P < 0.01), from saliva to rumen (r = 0.73, P < 0.01), and from lower gastrointestinal tract to plasma (r = 0.72, P < 0.01). Urinary P excretion was similar for all treatments (P = 0.35). It was, however, related to plasma P (r = 0.63, P < 0.01) and to net P flow to bone (accretion - resorption; r = -0.64, P < 0.01). Phosphorus intake affected net P flow to soft tissue (P = 0.04) but not net P flow to bone (P = 0.46). Phosphorus mobilized from bone was directed toward soft tissue, as suggested by the correlations between P flow from bone to plasma and net P flow to soft tissue (r = 0.89, P < 0.01), and P flow from plasma to soft tissue and net P flow to bone (r = -0.76, P < 0.01). The lack of effect of dietary P on net P accretion in bone suggests that P demand for bone formation was low and surplus P was partially used by soft tissue. In conclusion, the model resulted in appropriate biological description of P metabolism in sheep and added knowledge of the effects of surplus dietary P on P metabolism. Additionally, the model can be used as a tool to assess feeding strategies aiming to mitigate P excretion into the environment. |
| تدمد: | 1525-3163 0021-8812 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::c1f33563f260959822a834e9a6e4511d https://doi.org/10.2527/jas.2010-3669 |
| رقم الأكسشن: | edsair.doi...........c1f33563f260959822a834e9a6e4511d |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15253163 00218812 |
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