XII - 12th International Symposium - Digestive Physiology of Pigs

Digestive
Physiology
of Pigs
feed efficiency by 16% compared with control. In Exp. 2,
adding XB (200 g/MT) XB increased (P < 0.05) AID of DM,
CP, energy and mean indispensable AA by 2.4, 4.1, 3.3 and
4.6 percentage units, respectively, compared with control.
In conclusion, supplemental xylanase and β-glucanase in
pelleted nursery wheat and barley-based diets deficient
in DE resulted in improved energy and nutrient utilization,
resulting in better feed efficiency from weaning to 42 d of
age. Results of the 2 studies suggest that an enzyme product
containing a combination of xylanase and β-glucanase
activities allowed young pigs to derive more nutrients and
energy in a wheat and barley-based diet formulated to be
deficient in energy.
Key words: enzyme, pigs, digestibility
1047 Total-tract phosphorus digestibility of monocalcium
phosphate in 15-kg pigs. H. Zhai* and O. Adeola,
Purdue University, West Lafayette, IN, USA.
The objective of this study was to determine the
standardized total-tract phosphorus digestibility (SPD) in
monocalcium phosphate for 15-kg pigs using the regression
technique. Forty-eight pigs (initial BW 15.7 ± 1.53 kg) were
used in a randomized complete block design. There were
8 dietary treatments with 6 replicates per treatment. The
dietary treatments included a negative control (3.30 g/kg
total P) and 7 additional dietary treatments with incremental
addition of 0.74 g/kg P through monocalcium phosphate
resulting in a range of 3.30 to 8.45 g/kg total P in the dietary
treatments. The ingredient composition of the negative
control was 600 g/kg corn, 300 g/kg soybean meal, 64.85
g/kg cornstarch, 20 g/kg soybean oil, 3.3 g/kg salt, 6.05 g/
kg limestone, 3.0 g/kg vitamin + mineral premix, and 2.8
g/kg synthetic amino acids. Limestone was used to keep
the Ca:P ratio constant at 1.25 across all dietary treatments
and cornstarch was used to fill the slack. Five days were
allowed for the pigs to adapt, followed by a 5-d period of
total collection of feces. Fecal collection was initiated and
ended with the appearance of ferric oxide-marked feces.
Daily feed allowance was set at between 3.5 and 4.0%
of the BW of pigs to guarantee that the feed waste was
minimized. Water was supplied separately at an allowance
of 2 times the amount of feed. The results showed that
dietary P intake, fecal P output, and digested P increased
linearly (P < 0.001) with the increasing P level whereas the
apparent P digestibility in diets increased both linearly (P <
0.001) and quadratically (P = 0.007). The regression of daily
digested P against daily P intake gave an estimated SPD
67.5% for monocalcium phosphate and the endogenous P
losses at 494 mg/d, which translates to 1,023 mg/kg dry
matter intake. The r 2 with this linear regression was 0.93.
In conclusion, a strong linear relationship was obtained
between digested P and P intake; the SPD in monocalcium
phosphate was determined to be 67.5% for 15-kg pigs.
Key words: monocalcium phosphate, total-tract phosphorus
digestibility, pigs
1048 Ileal digestibility of amino acids in co-products
of corn processing into ethanol for pigs. O. Adeola,*
Purdue University, West Lafayette, IN, USA.
XII INTERNATIONAL SYMPOSIUM ON
DIGESTIVE PHYSIOLOGY OF PIGS
58
Session II
Barrows with an average initial BW of 45 kg and fitted with
T-cannula at distal ileum were fed 5 diets to determine the
apparent (AID) and standardized ileal digestibility (SID) of
amino acids (AA) in corn distillers dried grains (DDG), DDG
with solubles (DDGS), high-protein DDG (HPDDG) and
high-protein DDGS (HPDDGS). On a DM basis, the test
ingredients contained 33.7% CP, 19.2% ADF, and 53.1%
NDF for DDG; 30.3% CP, 11.8% ADF, and 40.6% NDF for
DDGS; 62.5% CP, 28.4% ADF, and 45.1% NDF for HPDDG;
and 52.4% CP, 17.4% ADF, and 30.4% NDF for HPDDGS.
The 5 diets consisted of a nitrogen-free diet (NFD) and 4
semi-purified diets in which the test ingredient was the sole
protein source with chromic oxide added at 5 g/kg as an
indigestible marker. The NFD was used determine basal
endogenous AA losses. Each diet was fed to 6 barrows
and each period consisted of a 5 d of adjustment period
and 2 d of ileal digesta collection for 10 h on each of d
6 and d 7. The results showed basal endogenous loss
ranged from 82 mg/kg DMI for Met to 3,390 mg/kg DMI for
Pro. Proline and Gly (1,122 mg/kg DMI) were the 2 most
abundant endogenous AA in endogenous flow and together
accounted for approximately 42% of the total endogenous
AA flow. The least abundant AA in endogenous AA flow were
Met and Trp (89 mg/kg DMI), which together accounted
for less than 2% of the total endogenous AA flow. Amino
acids in the test ingredients were well digested by pigs with
AID ranging from 70% for Lys in DDGS to 95% for Met in
HPDDG. Statistical difference (P < 0.05) in AID among test
ingredients were observed between HPDDG and DDGS for
most of the AA. Standardized ileal digestibility of the Lys for
DDG, DDGS, HPDDG, and HPDDGS were 88.6, 79.9, 94.6,
and 85.8%, respectively. Corresponding values for Met
93.9, 92.8, 97.1, and 94.6%. The SID of Lys was greater (P
< 0.05) in HPDDG than DDGS. In general, digestibility of AA
in the high-protein co-product of the dry-grind processing of
corn into ethanol was more than in the regular co-product
and less in the co-product with added solubles.
Key words: amino acids, pigs, standardized ileal
digestibility
1049 Total tract digestibility of nitrogen in pigs
exposed to high environmental temperatures. M.
Brestenský,* S. Nitrayová, P. Patráš, and J. Heger, Animal
Production Research Centre Nitra, Hlohovecká 2, Lužianky
951 41, Slovakia.
The effect of environmental heat stress on total tract
digestibility and retention of nitrogen (N) was studied using
7 gilts (initial BW 50.5 ± 1.7 kg). The pigs were housed in
metabolism cages in a climate-controlled room. After a 4-d
adaptation period, two 14-d experimental periods followed
during which the pigs were exposed to thermoneutral (NT;
20.6 ± 0.1°C) or high environmental (HT; 30.4 ± 0.4°C)
temperatures. Pigs were fed with a standard diet twice a
day in 2 equal doses at a daily rate of 90 g/kg 0.75 . Water
was offered ad libitum. In each experimental period, two
24-h balance periods were carried out on d 6–7 and 13–14
during which urine (via bladder catheters) and feces were
collected and subsequently pooled for N analysis. Based
on N intake and N excretion, N balance was calculated.
The experimental data were subjected to ANOVA and