XII - 12th International Symposium - Digestive Physiology of Pigs

Digestive
Physiology
of Pigs
Science, Winnipeg Manitoba, Canada, 5 Wageningen UR
Livestock Research, Lelystad, The Netherlands.
When fed to pigs, phytase increases the availability of
phytate bound phosphorus (P) in plant feedstuffs resulting
in a reduced requirement for additional dietary inorganic P.
Therefore, the total P content in the diet can be reduced,
which reduces feed cost and also results in reduced P
excretion which is important for environmental reasons.
The present study evaluated the dose response of a new
phytase (Buttiauxella expressed in Trichoderma reesei,
Danisco Animal Nutrition, Marlborough, UK) in weaned
piglets. Experiments were conducted at 2 different locations.
In both trials, piglets were fed a commercial post weaning
diet, followed by an experimental diet for a period of 12 to 14
d. Piglets were fed one of the following experimental diets
during the experimental period: a positive control (PC) diet,
a negative control (NC) diet with reduced P and calcium
(Ca), or the NC diet + graded doses of 250, 500, 750, 1000,
and 2000 FTU phytase/kg feed (for Trial A) or NC diet +
graded doses of 250, 500, 1000, and 2000 FTU phytase/kg
feed (for Trial B). Fecal sampling took place over the last 4 d
of the experimental period. Apparent total tract digestibility
of dry matter (DM), Ca and P was evaluated. In Trial A,
digestibility of P was (%): 57.2 for PC, 32.5 for NC, 59.4
for 250 FTU, 62.0 for 500 FTU, 63.8 for 750 FTU, 66.0 for
1000 FTU, and 67.3 for 2000 FTU. In Trial B, digestibility of
P was (%): 45.2 for PC, 28.4 for NC, 58.7 for 250 FTU, 64.1
for 500 FTU, 67.9 for 1000 FTU, and 70.9 for 2000 FTU. In
both studies, the reduction in P in the NC diets resulted in
poorer digestibility of P when compared with the PC diets
(P < 0.001). Phytase supplementation improved (P < 0.001)
P digestibility at all inclusion levels to the NC control diet.
Furthermore, these responses to increasing phytase dose
were linear and quadratic (P < 0.001). The improvement in
P digestibility at 250 FTU/kg averaged 74% of the response
found at 2000 FTU/kg.
Key words: Buttiauxella phytase, piglets, P digestibility
1130 hypophosphatemia during refeeding with cornsoy-blends
is prevented by addition of milk or permeate.
A. Hother 1 , M. Lykke 1 , T. Martinussen 2 , C. Mølgaard 1 ,
P. T. Sangild 1 , C. F. Hansen 3 , H. Friis 1 , K. F. Michaelsen 1 ,
and T. Thymann* 1 , 1 Department of Human Nutrition, University
of Copenhagen, DK-1958 Frederiksberg C, Denmark,
2 Basic Sciences and Environment, DK-1958 Frederiksberg
C, 3 Large Animal Sciences, DK-1870 Frederiksberg C.
Corn-Soy-Blends (CSB) may not meet the requirement
during recovery from acute malnutrition. A recent
reformulation to include more phosphorus (CSB+) and skim
milk powder (CSB++) was therefore introduced. We tested
the hypothesis that inclusion of skim milk powder or addition
of permeate, a cost-effective phosphorus-rich by-product
from the dairy industry, would prevent hypophosphataemia
during refeeding in a pig-model of acute child malnutrition.
Weaned pigs were nutritionally depleted for 7 weeks (wks)
by feeding a pure maize diet. They were then allocated to 4
groups given either pure maize (n = 8), CSB+ (n = 9), CSB+
added permeate (n = 9) or CSB++ (n = 10) for 3 wks. During
the initial nutritional depletion period, there was no change
XII INTERNATIONAL SYMPOSIUM ON
DIGESTIVE PHYSIOLOGY OF PIGS
88
Session II
in body weight. Average BW before refeeding was 7.6 ± 1.4
kg (mean ± sd). Relative to maize-fed pigs, refeeding with
CSB+, CSB+ added permeate or CSB++ showed, similar
increments in BW (2.42 kg; 95%CI:1.75;3.08), and bone
mineral density (0.03 g/cm2; 95% CI: 0.01;0.05). However,
refeeding with CSB+ created transient hypophosphataemia
during the first week of refeeding (25% reduction in serum
inorganic phosphate (S-Pi) level relative to maize-fed pigs,
95%CI: 9–37%)) but returned to pre-refeeding levels after
2 wks. In contrast, refeeding with CSB+ added permeate or
CSB++ prevented transient hypophosphatemia during the
first wk of refeeding and after 3 wks S-Pi was 21% (95%CI:
2–42%) higher in CSB++ fed pigs relative to CSB+ fed
pigs. The effect of refeeding with CSB+ added permeate
on S-Pi was at no time point during the 3 wks different
from the effect of CSB++. The content of phosphate in
milk products, including permeate seems to be effective to
prevent a transient decline in S-Pi and resulted in higher
S-Pi levels after 3 wks. This effect is likely due to the
higher bioavailability of phosphorus from milk products. We
conclude that addition of milk products to vegetable-based
refeeding diets may be important for malnourished patients
susceptible to hypophosphatemia during refeeding.
Key words: malnutrition, refeeding, phosphate
1131 Severe acute malnutrition (SAM) in early life
reduces gut function and structure. M. Lykke, A. Hother,
P. T. Sangild, K. F. Michaelsen, H. Friis, C. F. Mølgaard, and
T. Thymann,* Department of Human Nutrition, University of
Copenhagen, DK-1958 Frederiksberg C, Denmark.
Malnutrition is known to affect multiple organ systems
including the liver, heart, kidney and brain. However, relatively
little is known about gastrointestinal structure and function
during malnutrition, and most evidence is derived from cross
sectional studies. Our objective was to investigate effects of
malnutrition in a prospective study using a piglet model. We
hypothesized that a uniform maize flour diet, resembling
a diet commonly ingested in developing countries, would
induce symptoms of malnutrition and reduce gut structure
and function. Four-week old pigs were weaned and given
ad libitum access to either maize flour (MAIZE, n = 12) or
a nutritionally optimized diet (CONTROL, n = 12). Weekly
blood samples and anthropometric measurements were
collected. All pigs were euthanized after 7 weeks and organ
dimensions were determined. Relative to control, maizefed
pigs displayed very clear symptoms of malnutrition
as indicated by reduced body weight (8.3 ± 0.6 vs 32.4
± 1.2 kg; P < 0.001) and reduced hemoglobin (P < 0.01),
hematocrit (P < 0.05) and mean cell volume (P < 0.01) from
wk 3 and onwards. Villous height in both the proximal and
distal small intestine was significantly reduced in MAIZE
relative to CONTROL (proximal: 286 ± 17 µm, vs 623 ± 49
µm and distal: 268 ± 12 µm vs 421 ± 11 µm, both P < 0.001).
However, the difference in villous height was only to a minor
degree associated with a functional change in brush-border
enzyme activity, where sucrase was increased (2.16 ± 0.23
vs 1.60 ± 0.15 U/g, P < 0.05) and aminopeptidase A was
decreased (2.29 ± 0.21 vs. 3.18 ± 0.27 U/g, P < 0.05) in
MAIZE versus CONTROL. No differences in maltase,
lactase aminopeptidase N and dipeptidylpeptidase IV were