Y .-L. Yin et al. Livestock Production Science 62 2000 133 –141
135
al., 1992. However, there is little information about crude protein CP, energy and amino acids AAs
the use of TiO as a marker for determination of the were calculated for the two experiments. Ileal re-
2
ileal digestibility of nutrients in pigs. covery of TiO
and Cr O and IAD of DM, CP,
2 2
3
The present studies afforded the opportunity to 1 gross energy and amino acids measured with TiO
2
compare the use of Cr O and TiO as indigestible and Cr O
were compared by Student’s t-test. In
2 3
2 2
3
markers, 2 compare the PVTC with the IRA order to compare three methods PVTC TiO
2
method, 3 evaluate the PVTC method for quantita- marker, PVTC Cr O marker and PVTC total collec-
2 3
tive collection of digesta, using wheat and its by- tion, the 144 data values corresponding to 12 pigs 3
product-based diets with a range of fibre content. 4 periods 3 3 methods were analysed using a split
plot model with diets as the main plot factor and methods as the sub-plot factors. The analysis was
2. Materials and methods carried out using the REML procedure of the Genstat
5 Committee 1993. Because of the differences in Two separate studies were conducted. In experi-
location, pig breed and statistical design no statistical ment 1, 12 Large White Landrace boars, approxi-
comparison of the PVTC and IRA techniques was mately 26 kg, were fitted with post-valve ‘‘T’’ caecal
considered valid. cannulae PVTC according to the procedures of van
Leeuwen et al. 1991. The pigs were randomly allocated, in a four-period crossover design to eight
3. Results
diets based on wheat W, wheat plus middlings WM, wheat plus bran WB or recombined wheat
3.1. Ileal recoveries of TiO and Cr O
2 2
3
flour plus bran plus middlings, WR without or with xylanase addition. Each of the four main diets was
The ileal TiO and Cr O
recoveries for the
2 2
3
mixed as a single batch and then divided for enzyme experimental diets W, WR,WM and WB and the
addition. The diets, which contained both TiO and
2
average values are given in Table 1. With both Cr O as indigestible markers, were cold-pelleted 3
2 3
markers the recoveries measured with the PVTC mm die and fed dry. This experiment was conducted
method for diet WB were significantly P , 0.001 at The Queen’s University of Belfast. After a 5-d
lower than for the other diets, values for TiO and
2
adaptation period, faeces were collected for 7 d and Cr O being, respectively, 31 and 24 units less than
2 3
ileal digesta were collected for 12 h 08:00–20:00 h those for diet W. The ileal recovery of TiO for all of
2
on the next two days. the tested diets measured with the IRA method and
In experiment 2, 30 German Landrace barrows, for diets W, WR and WM measured with the PVTC
approximately 15 kg, were subjected to an ileo-rectal method were close to 100, whereas recoveries of
anastomosis by the procedure described by Hennig et Cr O were 11 units lower P , 0.001, for both the
2 3
al. 1986. The experiment was conducted at Ros- PVTC and IRA methods.
tock. The six diets, based on W, WM and WB, of As a consequence of the lower Cr O
recovery,
2 3
identical composition to those used in Belfast, were the average values for IAD of DM, CP, energy and
fed to five pigs per diet. Ileal digesta were collected AAs in the four diets measured with TiO
were
2
for 5 d after a 7-d adaptation period. Samples of ileal significantly higher than with Cr O Table 2.
2 3
digesta were pooled within period and pig for each dietary treatment and freeze–dried. TiO was mea-
2
sured according to Leone 1973. Cr O was mea- 3.2. Ileal apparent digestibility of nutrients
2 3
sured using the method of Saha and Gilbreath 1991 measured with markers
PVTC and total by atomic absorption spectrophotometry. Further
collection PVTC and IRA methods
details of the diet compositions and methods of analysis are given in a previous paper Yin et al.,
As illustrated in Table 3, apart from CP diges- 2000.
tibility P , 0.05, all diet 3 method interactions for Ileal recoveries of TiO
and Cr O , and ileal DM, CP and energy were highly significant P ,
2 2
3
apparent digestibility IAD of dry matter DM, 0.001. Apart from the numerically lower DM di-
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
