136 Y
.-L. Yin et al. Livestock Production Science 62 2000 133 –141 Table 1
Ileal recovery of TiO and Cr O
2 2
3
Diet W
WR WM
WB S.E.D.
P Mean
a a
a b
PVTC TiO
99.9 94.9
95.5 67.8
4.92 , 0.001
89.7
2 a
a a
b
Cr O 84.9
87.4 82.8
60.6 4.69
, 0.001 79.0
2 3
IRA TiO
98.8 ND
101.1 95.2
2.70 NS
98.4
2
Cr O 84.3
ND 88.7
86.8 2.39
NS 86.8
2 3
PVTC: Measured with PVTC total collection method. IRA: Measured with IRA method.
a,b
Values in the same row without a common superscript are significantly different P , 0.05. ND: Not determined.
Table 2
TiO and IRA methods for W, WR and WM but the
2
Comparison of average values of ileal apparent digestibility of
high fibre WB diet resulted in higher estimates of
nutrients in diets W, WR, WM and WB measured with PVTC
apparent digestibility by the total collection method.
cannula and either TiO or Cr O
2 2
3
TiO Cr O
S.E.D. P
2 2
3
DM 0.702
0.671 0.0095
, 0.001
4. Discussion
CP 0.772
0.748 0.0081
, 0.001 Energy
0.710 0.680
0.0084 , 0.001
4.1. Comparison of Cr O and TiO as markers
2 3
2
Threonine 0.747
0.72 0.0092
, 0.001
for determination of ileal apparent digestibility of
Valine 0.748
0.722 0.0074
, 0.001 Cystine
0.785 0.760
0.0083 , 0.001
nutrients
Methionine 0.888
0.880 0.0039
, 0.05 Isoleucine
0.810 0.790
0.0042 , 0.001
Low faecal recoveries of Cr O and TiO ranging
2 3
2
Leucine 0.820
0.801 0.0052
, 0.001
from 71 to 85 in pigs have been often reported in
Tyrosine 0.831
0.814 0.0048
, 0.001
the literature Mueller, 1956; Moore, 1957, 1959;
Phenylalanine 0.923
0.812 0.0199
, 0.001 Lysine
0.819 0.800
0.0054 , 0.001
Ishikawa, 1966; Ishikawa and Sugimura, 1973;
Histidine 0.850
0.834 0.0055
, 0.001
Moughan et al., 1991; Greer, 1992; McClean, 1993;
Arginine 0.883
0.870 0.0042
, 0.001
Yin et al., 2000. The present results show that the
Aspartic acid 0.756
0.730 0.0091
, 0.001
ileal recoveries of TiO and Cr O are much higher
2 2
3
Serine 0.812
0.792 0.0073
, 0.001
than those at the faecal level. For example, the ileal
Glutamic acid 0.892
0.881 0.0036
, 0.001 Proline
0.787 0.763
0.0061 , 0.001
recoveries of TiO and Cr O
measured with the
2 2
3,
Glycine 0.721
0.690 0.0086
, 0.001
IRA method, were 12.6 and 5.3 percentage units
Alanine 0.719
0.688 0.0054
, 0.001
higher, respectively, than the overall faecal re-
Total AAs 0.817
0.798 0.0061
, 0.001
coveries of TiO and Cr O observed by Yin et al.
2 2
3
2000. The nearly 100 ileal recovery of TiO for
2
gestibility for diet WM the results for PVTC using the low fibre diets W, WR and the medium fibre diet
TiO and for IRA were very similar, and, in line
WM obtained with the PVTC and IRA pigs indicates
2
with the expected effects of fibre, values declined that the disappearance of TiO
observed by Greer
2
from diet W to diet WB. Similar to the results for the 1992; McClean 1993 and Yin et al. 2000 did
digestibility of DM, CP and energy, ileal apparent not occur at the ileal level. This suggests that the
digestibilities of amino acids were also comparable lower recovery of marker in faeces is due to marker
between the PVTC TiO and IRA techniques, retention, or absorption or both in the large intestine.
2
except for valine, phenylalanine and proline. Values The reasons for retention and absorption in the large
for the DM, CP, gross energy and AA with PVTC intestine of pigs may be a combination of the long
using Cr O were lower than for the other methods. retention time 36 h of digesta Kidder and Man-
2 3
PVTC by total collection agreed well with the PVTC ners, 1978, the complex and capacious structure of
Y .-L. Yin et al. Livestock Production Science 62 2000 133 –141
137 Table 3
Comparison of ileal apparent digestibility of DM, CP, gross energy and selected AAs measured either with markers TiO or Cr O using
2 2
3
PVTC-cannula or by total collection PVTC or IRA
a
Diet TiO
Cr O PVTC
S.E.D. Diet 3 method
IRA
2 2
3
DM W
0.773 0.741
0.772 0.763
WR 0.766
0.752 0.783
ND WM
0.673 0.632
0.688 0.0155
P , 0.001 0.624
WB 0.594
0.556 0.732
0.597 CP
W 0.807
0.779 0.807
0.811 WR
0.804 0.790
0.808 ND
WM 0.757
0.727 0.769
0.0311 P , 0.05
0.747 WB
0.720 0.693
0.808 0.745
Gross energy W
0.787 0.757
0.777 0.784
WR 0.771
0.759 0.792
ND WM
0.683 0.644
0.698 0.0142
P , 0.001 0.656
WB 0.596
0.558 0.724
0.601 Threonine
W 0.77
0.737 0.768
0.764 WR
0.767 0.753
0.785 ND
WM 0.743
0.71 0.756
0.0128 P , 0.001
0.732 WB
0.708 0.68
0.794 0.702
Valine W
0.766 0.733
0.764 0.805
WR 0.777
0.763 0.793
ND WM
0.749 0.717
0.761 0.0123
P , 0.001 0.769
WB 0.701
0.673 0.797
0.756 Isoleucine
W 0.831
0.808 0.83
0.843 WR
0.837 0.826
0.848 ND
WM 0.803
0.778 0.813
0.0093 P , 0.001
0.815 WB
0.768 0.746
0.841 0.8
Leucine W
0.849 0.827
0.849 0.851
WR 0.841
0.832 0.853
ND WM
0.807 0.783
0.817 0.0121
P , 0.001 0.82
WB 0.78
0.76 0.85
0.807 Phenylalanine
W 0.935
0.83 0.85
0.876 WR
0.935 0.846
0.865 ND
WM 0.918
0.797 0.828
0.0068 P , 0.001
0.851 WB
0.904 0.777
0.861 0.834
Lysine W
0.843 0.811
0.834 0.844
WR 0.832
0.822 0.845
ND WM
0.82 0.797
0.829 0.0093
P , 0.001 0.833
WB 0.786
0.767 0.855
0.807 Histidine
W 0.865
0.845 0.864
0.869 WR
0.863 0.855
0.872 ND
WM 0.847
0.827 0.854
0.0075 P , 0.001
0.865 WB
0.825 0.808
0.882 0.848
138 Y
.-L. Yin et al. Livestock Production Science 62 2000 133 –141 Table 3. Continued
a
Diet TiO
Cr O PVTC
S.E.D. Diet 3 method
IRA
2 2
3
Tyrosine W
0.849 0.828
0.849 0.851
WR 0.853
0.844 0.863
ND WM
0.833 0.813
0.841 0.0082
P , 0.001 0.858
WB 0.789
0.771 0.856
0.834 Arginine
W 0.887
0.871 0.887
0.908 WR
0.882 0.875
0.89 ND
WM 0.886
0.871 0.89
0.0062 P , 0.001
0.901 WB
0.876 0.865
0.917 0.895
Aspartic acid W
0.777 0.746
0.776 0.799
WR 0.779
0.765 0.796
ND WM
0.751 0.72
0.764 0.012
P , 0.001 0.769
WB 0.716
0.689 0.807
0.75 Serine
W 0.834
0.81 0.833
0.836 WR
0.837 0.827
0.849 ND
WM 0.8
0.775 0.81
0.009 P , 0.001
0.801 WB
0.779 0.757
0.85 0.786
Glutamic acids W
0.909 0.897
0.908 0.912
WR 0.908
0.902 0.915
ND WM
0.879 0.863
0.885 0.0066
P , 0.001 0.873
WB 0.873
0.861 0.913
0.879 Proline
W 0.768
0.731 0.83
0.891 WR
0.881 0.874
0.732 ND
WM 0.763
0.733 0.763
0.0247 P , 0.001
0.858 WB
0.709 0.683
0.77 0.854
Glycine W
0.749 0.712
0.745 0.784
WR 0.742
0.726 0.761
ND WM
0.717 0.679
0.73 0.0157
P , 0.001 0.74
WB 0.675
0.644 0.782
0.732 Alanine
W 0.737
0.7 0.735
0.77 WR
0.75 0.734
0.769 ND
WM 0.719
0.683 0.732
0.0144 P , 0.001
0.741 WB
0.666 0.635
0.773 0.714
Total AAs W
0.833 0.81
0.832 0.856
WR 0.851
0.846 0.856
ND WM
0.808 0.784
0.817 0.0091
P , 0.001 0.825
WB 0.783
0.764 0.854
0.814
a
IRA not included in statistical analysis, since the experimental design was different from the PVTC experiment. ND: Not determined.
the large intestine Barnicoat, 1945; Moore, 1957; and Monaghan 1996 the present results highlight
1959 and the high specific gravity of TiO and
the problems of use of Cr O as a marker. Mean
2 2
3
Cr O Lide and Frederikse, 1995. values of the ileal recovery of Cr O measured with
2 3
2 3
In common with the studies of McCarthy et al. the IRA method was only 87 in this study.
1974, Moughan et al. 1991, Jagger et al. 1992 Consequently the ileal digestibility of DM, CP,
Y .-L. Yin et al. Livestock Production Science 62 2000 133 –141
139
energy and total AA measured with Cr O were
Cr O TiO
is insoluble in water, HCl, HNO or
2 3
2 3,
2 3
respectively 4.6, 3.2, 4.4 and 2.4 lower than those dilute H SO Merck Index, 1989 and analysis of
2 4
measured with TiO Table 2. Jagger et al. 1992 TiO
is a relatively simple and straightforward
2 2
found that the ileal digestibilities of N and AAs procedure. High recoveries 95–100 in samples of
measured with Cr O were significantly lower N,
feeds and excreta of poultry and pigs have been
2 3
6.7 and the average value of 11 AAs, 6.1 than reported Njaa, 1961; Leone, 1973; Peddie et al.,
those measured with TiO , when both markers were 1982; Jagger et al., 1992.
2
added to a barley and wheat based diet fed to growing and finishing pigs. Furthermore, the results
4.2. Comparison of methods for measurement of of Jagger et al. 1992 and of this experiment show
ileal apparent digestibility of nutrients that the standard errors associated with apparent ileal
digestibility values calculated using each marker The excellent marker recoveries with TiO for the
2
were lower with TiO than with Cr O
This is W, WR and WM with the PVTC method and for the
2 2
3.
somewhat surprising in that the level of incorpora- W, WM and WB diets with the IRA method indicate
tion of Cr O was higher than for TiO At these low
that, under these conditions, digesta collection was
2 3
2.
levels it would be possible for problems to arise due fully representative of the material reaching the
to lack of homogeneity of mixing. However, the low terminal ileum. This would be expected with the IRA
standard errors obtained with TiO would suggest
method where a complete 5-d collection was made
2
that diet mixing was not a problem. but it is noteworthy that similar results occurred with
The primary reason for the low recovery and the much shorter period of collection 24 h using the
variable results from Cr O may be related to
PVTC technique. However, the result for the high-
2 3
analytical problems arising mainly from interference fibre diet WB using the PVTC technique demon-
by other minerals present in the sample Williams et strates that quantitative collection of digesta was not
al., 1962; Saha and Gilbreath, 1991. For example, achieved. This result therefore supports the reports of
¨ Williams et al. 1962 found a 12 decrease in Cr
Kohler et al. 1991 and van Leeuwen et al. 1991 recovery when phosphate PO was added to the
of variable recovery with the PVTC technique
4
solution of Cr. Saha and Gilbreath 1991 also dependant on diet composition and confirms the
showed significant effects on recovery when varying necessity of using an appropriate indigestible marker.
the concentration of Ca, P or Mg in diets and faeces Although a direct statistical comparison of the
of pigs. These minerals occur in high concentrations PVTC and IRA techniques is not valid due to the
in the digesta or faeces of pigs. This possibility is separate locations in which the techniques were used
presently under investigation in our laboratory. In an and the different sources of pigs, the results given in
initial study, three levels of Cr O corresponding to Table 3 for PVTC TiO and IRA show close
2 3
2
5, 10, 20 ppm were added to the faeces of pigs which numerical agreement. This, taken with the excellent
had not received Cr O in the diet. The recoveries marker recoveries Table 1, suggests that both
2 3
were 88.0, 87.7, 83.3, respectively. This is similar methods were giving reliable estimates of ileal
to the mean recovery values reported by Saha and digestibility. Furthermore, the good agreement be-
Gilbreath 1991 and the mean ileal recovery of tween IRA and PVTC TiO for diet WB, where
2
Cr O measured in this study. PVTC collection was not quantitative, suggests that
2 3
In addition, although Cr O is insoluble in water, the digesta recovered was similar in composition to
2 3
it is slightly soluble in acids and alkalis Merck that by-passing the cannula.
Index, 1989 and therefore it might be soluble to a As discussed in the Introduction, the main advan-
certain extent in the acid or alkaline digestive juices tage of the end-to-end IRA technique is that it is a
of the gastrointestinal tract of pigs Moore, 1959 or quantitative method for collecting ileal digesta and,
the acid solution used during Cr analysis. Saha and therefore, it is not necessary to use any marker for
Gilbreath 1991 suggested that the soluble Cr might calculating digestibility. However, compared with
be lost due to the formation of volatile Cr com- the PVTC method, the main disadvantages are: 1
pounds at the sample digestion stage. Compared with relatively complex surgical procedures and post-
140 Y
.-L. Yin et al. Livestock Production Science 62 2000 133 –141 beans in diets for growing pigs. M.Sc. Thesis. The Queen’s
operative animal care. 2 Longer time for recovery
University of Belfast, Belfast.
from the surgery. 3 Need for greater care to
¨ Hennig, U., Noel, R., Herrmann, U., Wunsche, J., Mehnert, E.,
minimise skin irritation and discomfort due to the
1986. Nutrition–physiologic studies in pigs with ileo-rectal
outpouring of digesta around the hind legs. 4 The
anastomoses. 1. Operation methods, biochemical and mor- phological findings. Arch. Anim. Nutr. 36, 585–596.
need for additional water, minerals and vitamins to
¨ Hennig, U., Wunsche, J., Souffrant, W.B., Borgmann, E.,
offset the loss of the large intestine. Compared with
Kreienbring, F., 1992. Methodenverleich zur Bestimmung der
the IRA method, the surgery for the PVTC cannula-
ˇ ˇ ˇ
ˇ PrSzSkalen NShrstoffverdaulichkeit und AminosSureresorption
tion is much easier to perform and less severe on the
ˇ zwischen Schweinen mit ileorectal-anastomose und ileozSkal-
¨ ¨
Bruckenkanule. Arch. Anim. Nutr. 42, 197–211.
animals than the IRA procedure and the PVTC
Ishikawa, S., 1966. Reliability of polyethyleneglycol as an in-
cannulation technique causes less discomfort to the
dicator for digestion studies with swine. 1. Rate of passage of
animal. Furthermore this method permits simulta-
polyethyleneglycol through the digestive tract. Agric. Biol.
neous measurement of ileal and overall digestibility
Chem. 30, 278–284.
in contrast to the IRA method. Taking all of these
Ishikawa, S., Sugimura, K., 1973. Movement of polyethylalcohol through the digestive tract as a digestion indicator with swine.
aspects into account it is concluded that the PVTC
Agric. Biol. Chem. 37, 203–206.
method is a better method for measuring ileal
Jagger, S., Wiseman, J., Cole, D.J.A., Craigon, J., 1992. Evalua-
digestibility in most situations. It would, however, be
tion of inert markers for the determination of ileal and faecal
of considerable interest to make a direct comparison
digestibility values in the pig. Br. J. Nutr. 68, 729–739.
of the PVTC and SICV techniques.
Kidder, D.E., Manners, M.J., 1978. Digestion in the Pig, Kingston Press, Bath.
¨ Kohler, T., Huisman, J., Den Hartog, L.A., Mosenthin, R., 1990.
Comparison of different digesta collection methods to de-
5. Conclusions
