XII - 12th International Symposium - Digestive Physiology of Pigs

Digestive
Physiology
of Pigs
mixture made to match the macronutrient content of the
HPC diet. The diets provided (kg-1 DM) 11.6–10.7 g Ca,
6.67–6.25 g total P and 13.9–14.8 MJ ME. The ad libitum
intake was calculated according to each pig’s body weight,
and adjusted weekly. A digestibility and balance trial was
performed at approximately 75 kg BW. Average feed intake
was 3104 and 2643 g/d for the 0.95 and 0.80 x ad lib. FL.
Average daily gain attained a maximum value at 854 g
(18.87 g/MJ ME intake) with the diet containing 74 g ApDP
(5.32 g ApDLys)/kg DM. The ApDP content in the diet did
not alter Ca and P fractional apparent absorption, which
attained average values of 0.416 ± 0.0097 and 0.545 ±
0.0105. Correspondingly, Ca and P retention as a fraction
of intake remained unaffected at 0.402 ± 0.0103 and 0.401
± 0.0120, leading to 12.3 ± 0.34 and 7.24 ± 0.201 g Ca
and P retained per day, respectively. Ca urinary losses
were not enhanced by dietary protein supply in excess
to requirements, remaining at 0.251 ± 0.0211 g/day. Our
results fail to demonstrate in the pig a likely impact of protein
intake well above requirements on Ca absorption and renal
excretion, a matter of dispute in the literature (Conigrave
et al., 2008). The level of feeding had a significant positive
effect on the flow (g/day) of Ca and P absorbed (P < 0.05)
and on Ca and P daily retained (P < 0.05).
Key words: calcium absorption, phosphorous, protein
intake
1081 Nutrient digestibilities of degermed dehulled
corn, citrus pulp and soy protein concentrate by barrows.
U. S. Ruiz* 2,1 , M. C. Tomaz 1 , L. A. F. Pascoal 3,1 , P. H.
Watanabe 4,1 , A. B. Amorim 5,1 , G. M. P. Melo 1 , and E. Daniel 1 ,
1 São Paulo State University, Jaboticabal, SP, Brasil, 2 São
Paulo State University, Dracena, SP, Brasil, 3 Paraíba Federal
University, Bananeiras, PB, Brasil, 4 Ceará Federal University,
Fortaleza, CE, Brasil, 5 São Paulo State University,
Botucatu, SP, Brasil.
This study was carried out to determine ileal and total
tract apparent digestibilities (AD) of dry matter (DM),
crude protein (CP), gross energy (GE) and the respective
digestible components (digestible DM – DDM, digestible
protein – DP and digestible energy – DE) of degermed
dehulled corn, citrus pulp and soy protein concentrate by
pigs, by the difference approach. Thirty 2 barrows (28.1 ±
1.6 kg of BW) were fed a corn soybean meal basal diet or
one of 3 diets, formulated by replacing 30% of the basal
diet with 30% of one of the test feedstuffs, for 11 d. Chromic
oxide (0.3%) was included in the diets for calculating
nutrient digestibilities. Fecal material was collected from d
7 through d 11 by grab sampling and ileal digesta samples
were collected from the ileum after the animals were
slaughtered in d 12. Ileal AD of DM and total and ileal AD
of GE of degermed corn (77.4%, 88.7% and 77.7%) were
greater (P < 0.05) than that observed in citrus pulp (50.3%,
86.5% and 55.8%) and in soy protein concentrate (63.5%,
85.1% and 59.4%), which did not differ (P > 0.05). Total
AD of CP, total DP and total DE of soy protein concentrate
(87.5%, 500 g/kg and 3739 kcal/kg) were higher (P < 0.05)
than the values found in degermed corn (81.7%, 57.5 g/
kg and 3330 kcal/kg), which were greater (P < 0.05) than
that verified in citrus pulp (60.5%, 39.5 g/kg and 3223 kcal/
XII INTERNATIONAL SYMPOSIUM ON
DIGESTIVE PHYSIOLOGY OF PIGS
70
Session II
kg). Total and ileal DDM, ileal AD of CP and ileal DE of
degermed corn (782.1 g/kg, 673.3 g/kg, 70.7% and 2918
kcal/kg) and soy protein concentrate (778.0 g/kg, 570.1
g/kg, 78.7% and 2877 kcal/kg) were similar (P > 0.05)
and greater (P < 0.05) than the ones observed in citrus
pulp (737.0 g/kg, 436.1 g/kg, 50.6% and 2081 kcal/kg).
There was no difference (P > 0.05) between ileal DP of
degermed corn (49.8 g/kg) and citrus pulp (33.0 g/kg),
which were smaller (P < 0.05) than the value found in soy
protein concentrate (434 g/kg). Degermed corn presented
the smallest differences between total tract and ileal
digestibilities of DM and GE, and soy protein concentrate
showed the smallest difference for total tract and ileal
digestibilities of CP.
Key words: feedstuffs, digestion, pigs
1082 Microscopic matrix and in vitro degradation and
fermentation characteristics of wheat co-products from
flour milling in the pig intestine. R. Jha* 1 , A. Owusu-
Asiedu 2 , P. H. Simmins 2 , A. Pharazyn 3 , and R. T. Zijlstra 1 ,
1 University of Alberta, Edmonton, AB, Canada, 2 Danisco
Animal Nutrition, Marlborough, UK, 3 Nutreco Canada,
Guelph, ON, Canada.
Use of co-products from wheat flour milling (WFM) in pig
diets may ameliorate high feed cost. However, digestibility
of WFM is lower than feed grains, with limited information
about its fermentation characteristics and matrix structure.
In vitro degradation and fermentation characteristics of 6
WFM samples were studied: 2 shorts, 2 millrun, 1 middlings
and 1 bran; ADF, 12, 8, 13, 15, 11 and 16%; NDF, 32, 23,
34, 36, 27 and 49%, respectively. After a pepsin-pancreatin
hydrolysis, WFM were incubated in a buffer solution with
minerals and fresh pig feces as inoculum. Accumulated gas
production, proportional to amount of fiber fermented, was
measured for 72 h and modeled. Volatile fatty acid (VFA)
concentration was measured in the fermented solutions.
Principle component analysis indicated relations between
nutrient content and fermentation characteristics of WFM.
The matrix of WFM was analyzed using scanning electron
microscopy. The DM degradability during fermentation
ranged from 31% to 52% and correlated negatively with ADF
(r = −0.65, P < 0.01) and positively with CP (r = 0.50, P <
0.01) content of WFM. Total gas production ranged from 101
to 148 mL/g DM incubated and were negatively correlated
with ADF and CF (r = −0.70 and −0.59, respectively; P <
0.01). The VFA production ranged from 2.0 to 3.0 mMol/g
and the fractional rate of degradation from 0.08 to 0.11/h.
Microscopy indicated that nutrient content and not type of
WFM influenced the fiber-starch-protein matrix: matrix of
1 millrun and 1 shorts were highly interspersed, while the
matrix of the other millrun and shorts and middlings was
loosely imbedded. In conclusion, the matrix structure, fiber
components and CP were associated with degradability
and fermentability of WFM. Thus, treatments targeted to
reduce the impact of fiber and protein may increase the
digestibility and fermentability of wheat co-product from
flour milling.
Key words: fermentation, VFA, wheat co-products