XII - 12th International Symposium - Digestive Physiology of Pigs

Digestive
Physiology
of Pigs
Animal and Aquacultural Sciences, Norwegian University
of Life Sciences, Ås, Norway, 3 Department of Food Science,
Aarhus University, Tjele, Denmark, 4 Syddansk Kvæg,
Vojens, Denmark.
β-hydroxy β-methyl butyrate (HMB), a metabolite of leucine,
has proved to positively affect sow performance. However,
effects on nutrient absorption and hepatic metabolism are
unknown. A multi-catheter sow model was established to
study the effects of dietary HMB on net portal (NPF) and
net hepatic (NHF) fluxes of HMB, glucose, and the AAs:
Ala, Gly, Ile, Leu, Phe, Pro, Tyr and Val. Eight second parity
LY sows were fitted with permanent indwelling catheters
in an artery and in portal, hepatic and mesenteric veins.
Eight hourly sets of blood samples were taken, starting
30 min before the morning meal, on d-3 and d3 relative
to parturition. Control sows (CON) were fed a standard
lactation diet from d-15 and throughout the experiment.
HMB sows were fed the control diet with 15 mg Ca(HMB) 2 /
kg BW mixed in one third of the morning meal from d-10
until the day of parturition. Fixed effects of HMB on plasma
metabolites were tested while accounting for repeated
blood sampling within sow and day. Net portal flux of HMB
was affected by treatment (trt) (P < 0.01) and peaked at
6.85 mmol/h 30 min after the morning meal, and then
decreased toward preprandial level (−0.009 mmol/h) 3.5
h after the meal, indicating that dietary HMB was rapidly
absorbed from the intestine in the HMB sows. The NHF
of HMB tended to be affected by trt (P = 0.06) showing a
small hepatic uptake of HMB (1.05 mmol/h). The trt x time
interaction affected the NPF of glucose and studied AAs
(P < 0.01), except for Gly and Tyr. The NPF were always
positive, indicating absorption from gut to blood. The rates
of absorption appeared to be more stable for HMB sows
than for CON. Net hepatic flux of glucose was not affected
by HMB. It was negative, indicating hepatic uptake, 1.5
to 2.5 h after the meal, but otherwise positive, indicating
net hepatic release of glucose. Net hepatic fluxes of AAs
remained negative and were not affected by treatment. In
conclusion, HMB reduced the diurnal variation in glucose
and AA absorption and suggest that a more uniform
nutrient absorption to portal blood is advantageous for sow
performance.
Key words: portal flux, HMB, pig
1070 The degradation of arabinoxylan rich cell walls
in digesta obtained from piglets fed on wheat-based
diets by exogenous xylanases and auxiliary enzymes.
N. R. Pedersen* 1 , D. M. Le 2 , P. Fojan 2 , E. Azem 3 , J. Broz 3 , P.
Guggenbuhl 4 , and D. Pettersson 1 , 1 Novozymes, Bagsværd,
Denmark, 2 Aalborg University, Aalborg, Denmark, 3 DSM
Nutritional Products, Animal Nutrition & Health, 4002 Basel,
Switzerland, 4 DSM Nutritional Products, Animal Nutrition &
Health, 68305 Saint Louis cedex, France.
The objective of the present study was to compare the
ability of experimental and commercial xylanases to
degrade, in vitro, the arabinoxylan fraction in digesta from
pigs fed a wheat based diet. Piglets were sacrificed at 1,
2, 3, or 4 h after feeding and stomach and ileum contents
were isolated and frozen and later used for the in vitro
XII INTERNATIONAL SYMPOSIUM ON
DIGESTIVE PHYSIOLOGY OF PIGS
66
Session II
studies. Xylan solubilisation (measured as xylose) provided
information regarding the ability of the enzymes to degrade
the arabinoxylans during the harsh in vivo conditions
prevailing in the gastro intestinal tract. The hydrolytic
capacity of a commercial xylanase was compared with that
of an experimental xylanase using stomach digesta (pH 2.8)
obtained at 4 h after feeding. Relative to the control without
supplemental xylanase, both xylanases enzymes increased
(P < 0.05) xylose solubilisation 3 times compared with the
control. In the ileal digesta (1 h) the solubilisation was also
increased (P < 0.05) in a similar way for both xylanases
by 36%. Notably, inclusion of arabinofuranosidases in the
ileal digesta further increased (P < 0.05) the capacity of
the experimental enzyme to degrade the arabinoxylans
when compared with the commercial xylanase, with or
without supplemental arabinofuranosidases. However,
arabinofuranosidases added to either of the xylanases in
stomach samples did not increase to xylanase. Our results
illustrate clearly the importance of using different conditions
and substrates when enzyme performance is studied in
vitro as a pre-screening tool for setting up in vivo trials.
Key words: xylanase, digesta, xylose
1071 effects of dietary supplementation with a protease
on the apparent ileal digestibility of the weaned
piglet. P. Guggenbuhl* 1 , Y. Wache 1 , and J. Wilson 2 , 1 DSM
Nutritional Products France, 68305 Saint-Louis cedex,
France, 2 DSM Nutritional Products LCC, Parsippany, NJ,
United States.
The effects on the nutrient valorisation of an acid-stable
protease (Ronozyme ® ProAct) supplemented to a corn
soybean meal based diet were evaluated for the apparent
ileal nutrient digestibility in 120 28-d old weaned piglets
(8.17 ± 0.90 kg). Pigs were divided into 2 equal groups and
had free access to mash diet containing 0.4% chromium
oxide as indigestible marker (Std) or this diet supplemented
with the protease at a concentration of 200 mg/kg (Prot).
The analyzed added protease activities in the Std and Prot
diets were 0 and 107%, respectively. The ileal content
was collected for the digestibility determination after
euthanasia of 35 piglets of each group after 14 d of study
and 25 piglets of each group after 29 d. The piglets grew
similarly in both experimental groups. Compared with
group Std, the apparent ileal digestibility of total nitrogen
(68.7%) was (P ≤ 0.05) increased by 6.7% after 29 d of
treatment in group Prot. The digestibility of the essential
amino acids (80.4%), the sulfur amino acids (78.6%) and
the branched chain amino acids (78.3%) was (P ≤ 0.05)
increased at the end by 5.3, 6.9 and 5.8%, respectively.
The individual amino acids presented a tendency for a
better digestibility in the protease-supplemented animals
after 14 d of treatment. At the end of the study, the apparent
ileal digestibility of arginine (83.0%), aspartate-asparagine
(75.0%), glutamate-glutamine (80.6%), histidine (78.5%),
isoleucine (76.9%), lysine (89.5%), phenylalanine (78.4%),
threonine (69.5%), tyrosine (75.1%) and valine (76.2%)
in the Prot group was (P ≤ 0.05) increased by 3.7, 6.4,
6.3, 6.8, 7.8, 4.0, 4.5, 7.4, 5.4 and 8.8%, respectively. In
conclusion, protease increased apparent ileal digestibility
of amino acids by piglets.