Effects of concentration of dietary phosphorus on amount and route of excretion

Objectives were to determine the effect of dietary concentration of P in DM on routes of excretion of P and to evaluate direct and indirect measures of calculating DM digestibility and P excretion. Twelve lactating Holstein cows were fed 20 kg of DM containing 0.41% P daily for 4 wk and then were as...

Full description

Saved in:
Bibliographic Details
Published in:Journal of dairy science 1992-11, Vol.75 (11), p.3039-3049
Main Authors: Morse, D. (North Dakota State University, Fargo), Head, H.H, Wilcox, C.J, Van Horn, H.H, Hissem, C.D, Harris, B. Jr
Format: Article
Language:English
Subjects:
Animals
Cattle - metabolism
DIETA
DIGESTIBILIDAD
DIGESTIBILITE
Digestion
EXCRECION
EXCRETION
FECES
Feces - chemistry
Female
FOSFORO
HECES
Lactation
LAIT
LECHE
Milk - chemistry
MINERALES
MINERAUX
ORINA
PHOSPHORE
Phosphorus, Dietary - administration & dosage
Phosphorus, Dietary - pharmacokinetics
Phosphorus, Dietary - urine
REGIME ALIMENTAIRE
URINE
VACAS LECHERAS
VACHE LAITIERE
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Objectives were to determine the effect of dietary concentration of P in DM on routes of excretion of P and to evaluate direct and indirect measures of calculating DM digestibility and P excretion. Twelve lactating Holstein cows were fed 20 kg of DM containing 0.41% P daily for 4 wk and then were assigned randomly to one of three diets: low (.30%), medium (.41%), or high (.56%) in P for 9 wk. Total collections of excreta (feces and urine) and milk were made during wk 4, 7, 10, and 13. At wk 4, cows excreted 88.2% of P consumed daily: 68.6% of excreted P in feces, 1.0% in urine, and 30.3% secreted in milk. Cows assigned to the low P diet decreased intake by 26.8% and excretion of P in feces by 22.7% in wk 13 compared with wk 4, whereas cows fed the high P diet increased intake by 36.5% and excretion of P in feces by 48.6%. Digestibility of DM was 62.6% when calculated from total collection of feces but only 55.7 or 56.5% when estimated indirectly using Cr or acid detergent lignin as indigestible markers. Apparent excretion of P was less than that estimated using either of the marker techniques (49.7 vs. 59.1 and 58.1 +/- 0.7 g/d of P) because digestibility of DM was underestimated. A prediction equation was developed for P excretion based on P intake and milk production
ISSN:0022-0302
1525-3198
DOI:10.3168/jds.s0022-0302(92)78067-9