XII - 12th International Symposium - Digestive Physiology of Pigs

Digestive
Physiology
of Pigs
in ~2-fold higher ileal Vmax values without affecting the
SGLT1 glucose binding affinities in both segments (n = 5).
Administration of phlorizin decreased glucose induced Isc
(P < 0.01; n = 9), glucose flux rates (P < 0.001; n = 4) as
well as BBMV glucose uptake (P < 0.05; n = 3) at higher
level in the ileum as compared with the jejunum. Western
blot and mRNA analyses revealed that SGLT1 expression
was slightly higher in the jejunum. The expression analyses
of candidate modulators of segmental diverse SGLT1
activity revealed that SGLT3 was slightly more abundant
in the jejunum while the basolateral localized Na + /K+-
ATPase showed similar abundance and activity in both
segments. Electrogenic glucose absorption occurs more
efficient in the ileum than in the jejunum independent from
SGLT1 abundance. Posttranslational modifications of
SGLT1 might be responsible for these segmental transport
characteristics.
Key words: glucose, SGLT1, segment-specificity
1039 The impact of lower gut nitrogen supply on
nitrogen balance and urea kinetics in growing pigs.
D. Columbus* 1 , H. Lapierre 3 , M. F. Fuller 2 , and C. F. M. de
Lange 1 , 1 Department of Animal and Poultry Science, University
of Guelph, Guelph, Ontario, Canada, 2 Department
of Surgery, State University of New York, Stony Brook, New
York, USA, 3 Dairy and Swine Research and Development
Centre, Agriculture and Agri-Food Canada, Sherbrooke,
Quebec, Canada.
Nitrogen (N) absorption from the lower gut is generally
thought to be of little nutritional significance. However,
studies have shown the presence of amino acid (AA)
transporters in colonocytes. In addition, ammonia can be
absorbed from the lower gut, converted to urea, recycled
into the upper gut, and incorporated into microbial AA that
may be absorbed and utilized by the host. An N-balance
and isotope dilution study was performed to determine the
effect of lower gut N supply on N retention and urea kinetics
in growing pigs. Nine cecally cannulated and jugular
catheterized barrows (initial BW of 22.4 ± 1.2 kg) were
randomly assigned to 1 of 3 cecal N infusion treatments:
saline, casein, or urea, the latter 2 treatments infused at
a rate of 40% of daily N intake. The infusion period was
9 d in duration and consisted of a 5 d infusion adaptation
period followed by a 4 d N-balance period. 15 N 15 N-urea
was infused intravenously at a rate of 0.40 mmol/kg BW/d
during the N-balance period. Among essential AA, the
potential contribution of microbial protein to the host′s AA
supply is largest for valine, therefore, all pigs were fed a
valine-limiting cornstarch-soybean meal based diet at 2.8
times maintenance DE requirements in 3 equal meals.
There was no impact of cecal N infusions on apparent fecal
digestibility of N (P > 0.05). The efficiency (% of apparent
ileal digestible intake) of using N (72.9 ± 1.9, 84.9 ± 1.9,
and 85.6 ± 2.3%; P = 0.01; for saline, casein, and urea,
respectively) and valine (76.9 ± 1.9, 86.5 ± 1.9, and 86.5 ±
2.4; P = 0.02) for whole body protein and valine retention
increased for casein and urea. Urea flux and urinary N
excretion increased by the same increment for both N
infusions (P < 0.05) but this increase did not fully account for
lower gut N disappearance. Lower gut N disappearance is
XII INTERNATIONAL SYMPOSIUM ON
DIGESTIVE PHYSIOLOGY OF PIGS
55
Session II
in the form of non-protein N which can be used for microbial
AA production in the upper gut and – based on valine and
N utilization – improves body protein gain by more than
10%. Lower gut N metabolism should be considered when
determining N and AA requirements.
Key words: lower gut, microbial amino acids, urea
recycling
1040 Molecular weight distribution of soluble fiber
fractions and short-chain fatty acids in ileal digesta of
growing pigs. E. Ivarsson* 1 , R. Andersson 2 , and J. E. Lindberg
1 , 1 Department of Animal Nutrition and Management,
Swedish University of Agricultural Sciences, Uppsala, Sweden,
2 Department of Food Science, Swedish University of
Agricultural Sciences, Uppsala, Sweden.
The effect of fiber source on molecular weight (Mw)
distribution of soluble fiber fractions and short chain fatty
acids (SCFA) in ileal digesta of 7 post valve t-cecum
(PVTC) cannulated growing pigs was studied. The pigs
were fed semi-synthetic diets with sugar beet pulp (SBP)
or chicory forage (CFO) as fiber sources. The diets were
formulated to be similar in (~100 g/kg DM) total nonstarch
polysaccharides (NSP) and in soluble NSP (~20 g/
kg DM). The soluble NSP fraction in both diets originated
mainly from pectin. The Mw distribution of the soluble NSP
fraction in diets and ileal digesta were analyzed with a highperformance
size exclusion chromatography system. Three
Mw intervals (g/mol) were selected; MwL = 10 000 000 −1
000 000; MwM = 1 000 000–200 000 and MwS = 200 000–
10 000. The relative distribution (% of total) of molecules
in each interval was calculated. The SCFA in ileal digesta
was analyzed by high-performance liquid chromatography.
The MwL fraction was higher in diet SBP than in diet
CFO (19.8 vs. 9.8), whereas the MwS fraction was higher
in diet CFO than in diet SBP (34.5 vs. 45.5). There was
no (P > 0.05) difference between diets in the distribution
of the MwL fraction in ileal digesta. However, the MwM
fraction was higher in ileal digesta of pigs fed diet SBP (P
< 0.05) and the MwS fraction was higher in ileal digesta
of pigs fed diet CFO (P < 0.05). The mol-% of propionic
acid (HPr) was higher (P