[Influence of the ration content on the fecal phosphorus excretion of growing bulls varying in body weight].
Five smaller (body weight: 227.9 +/- 23.7 kg) and large growing bulls (435.2 +/- 14.3 kg per animal) each were fed with rations rich (chopped wheat straw:concentrate = 1:1) or poor in roughage (straw: concentrate = 1:4). Animals were kept in balance cages; 20 days adaptation period were followed by 10 days collection period. Body weight of bulls did not significantly influence apparent digestibility of rations. digestibility of organic matter of fibre rich ration was significantly lower (66.8%) than those of concentrate rich ration (74.4%). Feeding and body weight did not significantly influence metabolic parameters of mineral status. The fecal P-excretion amounted to 0.94 and 1.08 g per kg DMI in bulls fed with rations rich and poor in roughage. No influence of body weight was measured. Feeding and body weight did not significantly influence fecal P-excretion per kg DOMI (between 1.44 and 1.58 g P/kg DOM). For calculation of P-requirements for growing cattle fecal P-excretion amounted to 1.0 or 1.5 g P/kg DM and DOMI, respectively.
Klosch
M
M
Friedrich-Schiller-Universität Jena, Institut für Ernährung und Umwelt, Germany.
Richter
G H
GH
Schneider
A
A
Flachowsky
G
G
Pfeffer
E
E
D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight / Q000502:physiology; D002118:Calcium / Q000032:analysis / Q000378:metabolism; D002417:Cattle / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D004043:Dietary Fiber / Q000494:pharmacology; D004063:Digestion / Q000502:physiology; D004435:Eating / Q000502:physiology*; D005243:Feces / Q000737:chemistry*; D008297:Male; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism*; D014908:Triticum / Q000737:chemistry / Q000378:metabolism / Q000592:standards
D004043:Dietary Fiber; D010758:Phosphorus; D002118:Calcium