XII - 12th International Symposium - Digestive Physiology of Pigs

Digestive
Physiology
of Pigs
Jones,* N. K. Gabler, and J. F. Patience, Iowa State University,
Ames, IA, USA.
Although an increasingly important pathology, the etiology
of periweaning failure to thrive syndrome (PFTS) is still
unknown. Our objective was to determine if pigs with
PFTS differ from normal pigs in nutrient digestibility, blood
metabolites, thyroid hormone concentrations, organ weight,
intestinal structure and function. Ninety-six barrows were
selected from 960 weanling pigs to represent pigs from
each of the 10% lightest, median, and heaviest categories.
Pigs were placed in metabolism cages and allowed ad
libitum water and feed. Growth rate was evaluated for 27 d
and a 3-d urine and fecal grab sample collection for nutrient
digestibility determination by the marker method. Pigs with
ADG 2 standard deviations below the mean were considered
PFTS (n = 4). These pigs also met the clinical case
definition of PFTS. All other pigs (n = 92) were considered
normal contemporaries. At the end of the experiment,
pigs were fasted overnight, and whole blood and serum
were collected. Pigs were euthanized and organ weights
collected. Ileal segments were sampled for morphology
and absorptive capacity by Ussing chambers. Data were
analyzed using the GLIMMIX procedure of SAS. Pigs with
PFTS had slower ADG (167 vs. 568 g/d, P < 0.0001), which
may be attributed to less feed intake (222 vs. 680 g/d, P <
0.0001) and lower gross energy digestibility (83.9 vs. 86.6%,
P < 0.001). Compared with normal pigs, PFTS pigs had
decreased blood hemoglobin (P < 0.04), albumin, sodium,
and anion gap concentrations, suggesting anemia. Pigs
with PFTS also had lower serum T3 concentrations (2.7 vs.
3.3 ng/mL, P < 0.01), but similar T4 and IGF-1 levels. These
pigs also had increased digestive organ weights relative to
body size (P < 0.02), suggesting a higher maintenance cost.
Finally, PFTS was associated with increased ileum crypt
depth (210 vs. 257 µm, P < 0.0001), but not villous height or
differences in absorptive capacity. These are the first data
to explain PFTS in a nutritional context, and suggest it is
driven by poor appetite and nutrient digestibility, but not ileal
morphology or absorptive capacity.
Key words: nutrition, periweaning failure to thrive syndrome,
pig
1042 The contribution of portal-drained viscera to circadian
homocysteinemia in pigs. J. J. Matte* 1 , F. Guay 2 ,
and C. L. Girard 1 , 1 Agriculture and Agri-Food Canada,
Sherbrooke, Qc, Canada, 2 Université Laval, Québec city,
Qc Canada.
Homocysteine (Hcy) is an intermediary sulfur-containing
amino acid produced by the methylation process within
all cells. It is known as a powerful prooxidant with multiple
deleterious effects on immune and physiological functions.
Blood plasma total Hcy (tHcy), the most common indicator
of Hcy status, can be reduced by dietary folates or vitamin
B 12 but, in pigs, values remain 2 to 5 times higher than in
other mammalians. Homocysteinemia is routinely assessed
after an overnight fast (≥12 h) although no information is
available on circadian tHcy changes. Using a sub-group of
pigs from a study on portal appearance of vitamin B 12 after a
single meal containing 0, 25 or 250 µg of cyanocobalamin,
XII INTERNATIONAL SYMPOSIUM ON
DIGESTIVE PHYSIOLOGY OF PIGS
56
Session II
the present study aimed to report the circadian kinetic of
post-meal blood plasma tHcy and estimate the contribution
of portal drained viscera (PDV) to the systemic tHcy. Four
pigs (39.7 ± 1.07 kg BW) were surgically equipped at 101.0
± 8.2 d of age with catheters in the portal vein and carotid
artery; an ultrasonic flow probe was also fitted around the
portal vein for blood flow recordings. Blood samples were
collected simultaneously from the 2 catheters once before
meal and every h during 24 h after ingestion of 1.2 kg of
a vitamin-free semi-purified diet. Arterial tHcy changed
considerably during the post-meal 24-h period (P < 0.001;
SE 0.25); in fact, none of the net flux values differed from
zero (P > 0.07). These results suggest that systemic tHcy
is mostly produced during the first 12-h following a meal
by metabolic pools other than PDV. It appears that an
overnight fast of 12 h will reflect the peak rather than the
basal value for tHcy. The duration of the fasting period is
therefore a critical factor for a reliable interpretation of tHcy
homeostasis in pigs; such information may be also relevant
for human health and nutrition.
Key words: homocysteine, circadian, pig
1043 Dietary energy density affects the preference
for protein or carbohydrate solutions and piglet performance
after weaning. S. A. Guzmán-Pino 1 , D. Solà-
Oriol* 1 , J. Figueroa 1 , E. Borda 2 , and J. F. Pérez 1 , 1 Universitat
Autònoma de Barcelona, Bellaterra, Spain, 2 Bioibérica,
Palafolls, Spain.
Physiological state or the dietary nutrient content are
key determinants of sensory perception and reflect feed
preferences. The aim of the present study was to assess
whether the preference for protein or carbohydrate is
affected by dietary energy source for piglets. A total of 240
weanling piglets (2 8d-old, initial BW 7.18 ± 0.01 kg) were
allocated in 24 pens (10 pigs/pen) according to body weight.
Piglets were split up in 2 groups and had ad libitum access
to a high energy (HE, 3.90 Mcal DE/kg, crude fat 129 g/kg)
or a low energy diet (LE, 3.35 Mcal DE/kg, crude fat 60 g/kg)
with similar CP content (190 g/kg) and water from weaning
to 21 d. Piglet performance and the preference for protein
(porcine digestible peptides (PDP, Palbio 62SP ® ) 20 g/l) or
carbohydrate (sucrose 20 g/l) solutions were measured on
14 and 21d after weaning by using a double-choice test
(DCHT) protocol. Up to 14 d, LE diet promoted a higher
ADFI, ADG and BW than HE diet (ADG 198 vs. 155 g/d;
P < 0.01). The same situation was observed on 21 d after
weaning, with higher piglet BW for the animals fed the LE
diet than those fed the HE diet (12.8 vs. 11.5 kg; P < 0.001).
Higher growth was achieved for the animals fed a higher
protein-to-energy ratio (56.7 vs. 48.7 g CP/Mcal DE; P <
0.01). No preference (P > 0.05) was observed for protein
or carbohydrate solutions on 14 or 21d in piglets fed the LE
diet. On the other hand, the animals fed the HE diet showed
high preference (75% on 14 d and 65% on 21 d, P < 0.01)
for sucrose solution. In conclusion, dietary energy level and