A comparison of calcium and phosphorus requirements according to different standards in dry cows
S. Kinal 1,   J. Preś 1,   A. Korniewicz 2,   E. Chrząszcz 2,   T. Kistowski 2
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Department of Animal Nutrition and Feed Management, Wrocław Agricultural University, Norwida 25/27; 50-375 Wrocław, Poland
Experimental Station of the Research Institute of Animal Production, Czechnica, 55-011 Siechnice, Poland
Publication date: 1996-01-12
J. Anim. Feed Sci. 1996;5(1):11–23
Twenty-four dry cows were divided into 3 groups and fed maize silage, meadow hay and ground barley in amounts covering their nutritients, calcium and phosphorus requirements according to INRA, DLG or NRC standards. Mineral mixture - Polfamix, produced according to our formula, NaCl, limestone and ammonium phosphate were used as vitamin-mineral additives. The digestibility of dietary nutrients and nitrogen and mineral (Ca, P, Mg, Na, Zn and Cu) balance were determined in each cow 3-4 weeks before calving. Nutrients digestibility, calcium absorption (46.3%) and retention (25 g/d/cow) were higher in cows fed according to INRA standards than using the DLG and NRC systems. In cows from all groups, absorption (14-24%) and retention (3-7 g/d/cow) of phosphorus were low, but the highest values were in cows fed according to the INRA system. True absorption of Ca and P calculated according to the DLG and INRA systems equaled, respectively: Ca, 60-64 and 62-65%; P, 42-57 and 65-87%. Serum Ca and P levels in the cows corresponded to the retention of these elements.