XII - 12th International Symposium - Digestive Physiology of Pigs

Digestive
Physiology
of Pigs
> 0.05) on the ATTD of energy among treatments. Pigs fed
the S1.0 diet had higher (P < 0.05) serum Fe concentration
compared with those fed the CON and S0.5 diets at the
end of the experiment. There was no difference in total
iron–binding capacity among dietary treatments. Dietary
application of sericite didn′t affect the ammonia, hydrogen
sulfide, and total mercaptans emission on d 1, 3, 5, and 7.
In conclusion, dietary supplementation with 0.5 and 1.0%
sericite increased the ATTD of DM and N, whereas the
inclusion of 1.0% sericite reduced serum Fe concentration
in growing pigs.
Key words: apparent total tract digestibility, sericite, growing
pigs
1078 effects of faba beans and faba bean hulls on the
expression of selected genes in the small intestine of
piglets. A. J. M. Jansman,* J. van Baal, H. C. A. Widjaja,
J. van der Meulen, and M. A. Smits, Wageningen UR Livestock
Research, Lelystad, The Netherlands.
In a study using the small intestinal perfusion technique
in pigs, the effects were studied of intestinal perfusion
of ground fava beans, fava bean hulls or saline on the
intestinal net fluid absorption in intestinal segments
either or not challenged with an enterotoxigenic E. coli
(ETEC). After an 8 h perfusion test, the piglets were
euthanized and small intestinal mucosa samples were
taken for analyzing the expression of several selected
genes, which were previously shown to be responsive
toward an ETEC challenge. Samples of frozen of the
jejunal mucosa were ground in liquid nitrogen and total
RNA was extracted and purified. Real-time quantitative
PCR (qPCR) was performed. Each sample was run in
duplicate. The expression of the following genes coding
for the following proteins was quantified relative to the
quantity of 18S RNA: 1) apolipoproteine C3 (ApoC3), 2)
metalloproteinase 1 inhibitor (TIMP1), 3) aquaporine 8
(AQP8), 4) matrix metalloproteinase 1 (MMP1), 5) mucin
13 (MUC13) and 6) pancreatitis-associated protein (PAP).
There was a significant interaction between the effects of
perfusion treatment (saline, fava beans or fava bean hulls)
and ETEC challenge on the expression of the genes in
mucosal tissue, except for MUC13. Nature of the perfusion
treatment had a significant effect on the expression of
AQP8 and MUC13, while the ETEC challenge had a
significant effect on the expression of all selected genes,
except for MUC13. The expression of APOC3 and
AQP8 was increased by the ETEC challenge, while the
expression of TIMP1, MMP and PAP was decreased as
a result of the ETEC challenge. Overall, the expression of
APOC3 and AQP8 was negatively correlated with net fluid
absorption, while the expression of TIMP1, MMP1 and PAP
was positively correlated with net fluid absorption. It was
concluded that the expression of ETEC responsive genes
in the small intestinal mucosa is affected by perfusion with
fava beans and fava bean hulls and challenge with ETEC.
The expression of several genes (APOC3, AQP8, TIMP1,
MMP and PAP) was correlated with the net fluid absorption
in the small intestine of pigs.
Key words: intestinal gene expression, faba beans
XII INTERNATIONAL SYMPOSIUM ON
DIGESTIVE PHYSIOLOGY OF PIGS
69
Session II
1079 Improved nutrient digestibility and retention
partially explains feed efficiency gains in pigs selected
for low residual feed intake. A. J. Harris,* J. F. Patience,
S. M. Lonergan, J. C. M. Dekkers, and N. K. Gabler, Iowa
State University, Ames, IA 50011, USA.
Residual feed intake (RFI) is a unique measure of feed
efficiency (FE) and an alternative to traditional measures
of gain:feed or feed:gain. It is defined as the difference
between the actual feed intake of a pig and its expected feed
intake based on its level of growth and backfat. Therefore,
selecting for a pig with low RFI results in a more feed
efficient animal for a given rate of growth. Our objective was
to determine the extent to which apparent total tract nutrient
digestibility (ATTD), energy utilization and retention explain
FE differences between pigs divergently selected for low or
high RFI. After 7 generations of selection, 12 high (HRFI)
and 12 low RFI (LRFI) pigs (62 ± 3 kg BW), were randomly
assigned to metabolism crates. Pigs were fed ad libitum
a standard corn-soy diet containing 0.4% titanium oxide,
an exogenous digestibility marker. After a 7 d acclimation
period, total urine and feces collection was undertaken for
72 h. Nutrient and energy digestibility, P digestibility and N
balance were then measured and calculated to determine
differences between the RFI lines. As expected, ADFI was
significantly lower in the LRFI pigs (2.0 vs 2.6 kg/d, P <
0.01), ADG did not differ, and FE was significantly higher
in the LRFI (P = 0.0003) compared with the HRFI pigs. The
digestibility coefficients for DM (87.3 vs 85.9%), N (88.3 vs
86.1%), and GE (86.9 vs 85.4%) were higher (P ≤ 0.003)
in the LRFI versus HRFI pigs, respectively. DE (16.59 vs
16.32 MJ/kg DM) and ME (15.98 vs 15.72 MJ/kg DM)
values were also significantly greater (P = 0.0006) in the
LRFI pigs. When correcting for ADFI, P digestibility did not
differ between the lines. However, the LRFI pigs tended to
have improved N retention compared with HRFI pigs (36.91
vs 32.12 g/d, P = 0.08). These data suggest that differences
in energy and nutrient digestibility, utilization, and retention
may partially explain the superior FE seen in pigs selected
for LRFI.
Key words: residual feed intake, feed efficiency, nutrient
digestibility
1080 Dietary protein content does not influence calcium
and phosphorus absorption and retention in the
Iberian pig growing from 50 to 100 kg body-weight. R.
Nieto,* A. Haro, C. Delgado-Andrade, I. Seiquer, and J. F.
Aguilera, Institute of Animal Nutrition, Estación Experimental
del Zaidín, CSIC, Granada, Spain.
The comparatively slower growth rate of the Iberian
pig suggests lower Ca and P requirements than those
reported for conventional or high-performing porcine
breeds. The effects of dietary apparent-digestible protein
content (ApDP) from excessive to marginally deficient
(113, 93, 74 and 53 g/kg DM) and level of feeding (FL;
0.80 and 0.95 x ad libitum) upon whole-body retention of
Ca and P was studied in 48 purebred Iberian barrows in
the finishing stage from 50 to 100 kg BW. The diets were
prepared by diluting a high-protein diet (HPC), formulated
according to the ideal protein concept, with a protein-free