Agriculture Reference
In-Depth Information
18
16.2
15.8
16
14
12
10.6
10.3
10
8.6
8.5
8.1
7.9
7.6
7.4
7.3
8
7.1
6.8
6.8
6
4
2
0
1985
1990
1996
2000
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Year
Fig. 3.9.
Phosphorus excretion from grower-finisher pigs, g kg
−1
gain from 1985 to 2012. The initial body
weight is 30 kg during all years, but the body weight at slaughter has increased from 95 to 107 kg in 2012.
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Low
Medium
High
Excreted in faeces
Excreted in urine
Net absorbed
Retention
Fig. 3.10.
The relationship between P intake, P absorption, P retention and P excretion in urine and faeces
in the grower-finisher pig.
has also increased whereas the net P absorption
still increases (Poulsen, 1994). It is obvious that
a massive urinary P excretion indicates that the
pig is fed excessive P amounts. A perfect P efficiency
requires at the same time, a high P absorption
(corresponding to a low faecal P excretion) and
a low urinary P excretion. Figure 3.10 clearly
shows that P absorption is not down-regulated to
