ORIGINAL PAPER
A comparison of calcium and phosphorus
requirements according to different standards
in dry cows
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1
Department of Animal Nutrition and Feed Management,
Wrocław Agricultural University,
Norwida 25/27; 50-375 Wrocław, Poland
2
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
KEYWORDS
ABSTRACT
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.