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Effects of six carbohydrate sources on dog diet digestibility and post-prandial glucose and insulin response

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The effects of six extruded diets with different starch sources (cassava flour, brewer's rice, corn, sorghum, peas or lentils) on dog total tract apparent digestibility and glycemic and insulinemic response were investigated. The experiment was carried out on thirty-six dogs with six dogs per diet in a completely randomized design. The diets containing brewer's rice and cassava flour presented the greatest digestibility of dry matter, organic matter and gross energy (p < 0.05), followed by corn and sorghum; pea and lentil diets had the lowest. Starch digestibility was greater than 98% in all diets and was greater for brewer's rice and cassava flour than for lentils and peas diets (p < 0.05). Dogs' immediate post-prandial glucose and insulin responses (AUC < or = 30 min) were greater for brewer's rice, corn, and cassava flour diets (p < 0.05), and later meal responses (AUC > or = 30 min) were greater for sorghum, lentil and pea diets (p < 0.05). Variations in diet digestibility and post-prandial response can be explained by differences in chemical composition of each starch source including fibre content and starch granule structure. The nutritional particularities of each starch ingredient can be explored through diet formulations designed to modulate glycemic response. However, more studies are required to support these.
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ORIGINAL ARTICLE
Effects of six carbohydrate sources on dog diet digestibility and
post-prandial glucose and insulin response*
A. C. Carciofi
1
, F. S. Takakura
1
, L. D. de-Oliveira
1
, E. Teshima
1
, J. T. Jeremias
1
, M. A. Brunetto
1
and
F. Prada
2
1 Department of Veterinary Clinic and Surgery, Faculty of Agrarian and Veterinarian Sciences, Sao Paulo State University (UNESP), Jaboticabal,
Brazil, and
2 Faculty of Veterinary Medicine and Animal Science, University of Sao Paulo (USP), Sa
˜o Paulo, Brazil
Introduction
Carbohydrates are the main sources of energy for
many body functions. They are an important compo-
nent of pet foods comprising 30% to 60% of dry
foods and up to 30% of canned formulations. Most
of the carbohydrates found in these products come
from starch. Total tract apparent digestibility of
starch by adult dogs has been reported to be higher
than 95% (Walker et al., 1994; Murray et al., 1999),
although some investigations have demonstrated
that this may change with the type of starch present
in the diet (Belay et al., 1997; Murray et al., 1999;
Twomey et al., 2002). Differences in starch digest-
ibility between sources are because of factors like
cereal type, starch-protein interactions, physical
granule form, starch type, digestion inhibitors, pro-
cessing and particle size after processing (Rooney
and Pflugfelder, 1986; Wolter et al., 1998; Svihus
et al., 2005).
Starch is also the main nutrient responsible for
altering and influencing post-prandial insulin and
glucose responses in both dogs and human beings
(Nguyen et al., 1994; Wolever and Bolognesi, 1996),
and it is known that faster and more complete diges-
tion and absorption of starch leads to greater human
Keywords
canine, digestion, ingredient, meal response,
starch
Correspondence
A. C. Carciofi, Departamento de Clı
´nica e
Cirurgia Veterina
´ria, Faculdade de Cie
ˆncias
Agra
´rias e Veterina
´rias, UNESP, Via de Acesso
Prof. Paulo Donato Castellane, s/n. Jaboticabal
14.884-900 – SP, Brazil. Tel: +55 16 3209
2626; Fax: +55 16 3203 1226; E-mail:
aulus.carciofi@gmail.com
*Presented as part of the 10
th
Congress of
the European Society of Veterinary and
Comparative Nutrition held in Nantes, France,
October 5–7, 2006.
Received: 28 February 2007;
accepted 04 November 2007
First published online: 13 March 2008
Summary
The effects of six extruded diets with different starch sources (cassava
flour, brewer’s rice, corn, sorghum, peas or lentils) on dog total tract
apparent digestibility and glycemic and insulinemic response were inves-
tigated. The experiment was carried out on thirty-six dogs with six dogs
per diet in a completely randomized design. The diets containing
brewer’s rice and cassava flour presented the greatest digestibility of dry
matter, organic matter and gross energy (p < 0.05), followed by corn
and sorghum; pea and lentil diets had the lowest. Starch digestibility
was greater than 98% in all diets and was greater for brewer’s rice and
cassava flour than for lentils and peas diets (p < 0.05). Dogs’ immediate
post-prandial glucose and insulin responses (AUC £30 min) were
greater for brewer’s rice, corn, and cassava flour diets (p < 0.05), and
later meal responses (AUC 30 min) were greater for sorghum, lentil
and pea diets (p < 0.05). Variations in diet digestibility and post-prandial
response can be explained by differences in chemical composition of
each starch source including fibre content and starch granule structure.
The nutritional particularities of each starch ingredient can be explored
through diet formulations designed to modulate glycemic response.
However, more studies are required to support these.
DOI: 10.1111/j.1439-0396.2007.00794.x
326 Journal of Animal Physiology and Animal Nutrition 92 (2008) 326–336 ª2008 The Authors. Journal compilation ª2008 Blackwell Publishing Ltd
post-prandial responses (Wolever and Bolognesi,
1996). Other dietetic factors that influence these
responses are diet composition (Nuttall et al., 1984;
Welch et al., 1987; Nishimune et al., 1991; Nguyen
et al., 1998) and processing conditions.
Physiological and pathological states like diabetes
mellitus, obesity, pregnancy, stress, infection, cancer
and advanced age can alter glycemic control (Kahn
et al., 2001). In these situations, the use of a diet
that minimizes – while prolonging – post-prandial
glucose and insulin responses could improve glyce-
mic control and dog welfare (Bouchard and Sunvold,
1999). However, studies on the glucose responses of
potential dog food ingredients are few (Nguyen
et al., 1994; Graham et al., 1994; Bouchard and
Sunvold, 1999).
Therefore the objective of the research reported
here was to investigate the effects of cassava flour,
brewer’s rice, corn, sorghum, peas and lentils on diet
digestibility and the glycemic and insulinemic post-
prandial responses of dogs.
Materials and methods
Animals
Thirty-six neutered mixed-breed dogs, being 21
females and 15 males with body condition scores
between 4 and 6 (Laflamme, 1997), mean body
weight (BW) of 12.5 1.24 kg and mean age of
31.5 years were used in diet digestibility and
meal response tests. The animals were kept in the
Laboratory of Nutrition and Nutritional Diseases at
Sao Paulo State University (Jaboticabal, Brazil). Dur-
ing the digestibility and post-prandial response
experiments the subjects were housed individually
in 1.5 ·1.5 m kennels and had access to fresh water
ad libitum. The Ethics Committee for Animal
Well-Being at the Faculty of Agrarian and Veterinary
Sciences, Sao Paulo State University approved all
experimental procedures.
Diets
In total, six diets were tested and the ingredient
composition of each is reported in Table 1. Each
diet incorporated one of the following carbohy-
drates as its exclusive source of starch: corn,
brewer’s rice, sorghum, peas, lentils, or cassava
flour. Based on chemical compositions of the carbo-
hydrates sources evaluated, additional ingredients
were used to obtain balanced diets containing per-
centages [dry matter (DM) basis] of starch, fat, cal-
cium and phosphorus as similar as possible. Isolated
soybean protein was used to equalize the formula-
tion. All diets contained the same amount of added
salt, vitamins and trace minerals. The amount of
total dietary fibre (TDF) varied according to the
concentration found within the source carbohy-
drate. Chromium oxide (purity 99% w/w; Merck,
Darmstadt, Germany) served as a digestibility mar-
ker and was added to achieve a final concentration
of 3.5 g/kg of diet. Diets were formulated in accor-
dance with the AAFCO (2000) nutrient guide for
dogs, and balanced to meet maintenance require-
ments before being extruded and kibbled under
identical process conditions. The chemical composi-
tion of carbohydrate sources and experimental diets
is shown in Table 2.
Digestibility protocol
The apparent digestibility trial was conducted
according to AAFCO (2000) guidelines for using the
marker method. A 5-day-test-diet adaptation phase
preceded 5 days of faeces collection during the
experimental period. The quantity of diet allotted
was calculated using standard equations that deter-
mine the energy requirements for individual dog
maintenance [maintenance energy (ME in kcal) =
132 ·BW
0.75
kg], in compliance with National
Research Council (1985). Food was weighed each
day, divided into two equal portions and left out at
9am and 5 pm in stainless steel bowls. Bowls were
removed before the next meal and any uneaten food
was weighed and recorded. Faeces were collected
twice daily, weighed, and kept frozen ()15 C) until
analysis. A more detailed description of the proce-
dure for determining apparent digestibility in dogs
with the marker method can be found in Carciofi
et al. (2007).
Faecal samples were scored according to the fol-
lowing system: 1 = watery liquid that can be
poured; 2 = soft, unformed – stool assumes shape of
container; 3 = soft, formed, moist – softer stool that
retains shape; 4 = hard, formed, dry stool – remains
firm and soft; 5 = hard, dry pellets small, hard
mass. Faecal pH was determined by mixing 5 ml of
distilled water with 5 g of faeces and measuring the
result with a pH meter (model Q-400-Bd, Quimis,
Brazil).
Post-prandial response tests
Some days after the digestibility trials finished, dogs’
post-prandial glycemic and insulinemic responses
were evaluated following the procedure of Holste
A. C. Carciofi et al. Evaluation of carbohydrate sources for dogs
Journal of Animal Physiology and Animal Nutrition. ª2008 The Authors. Journal compilation ª2008 Blackwell Publishing Ltd 327
et al. (1989), excluding the samples taken at 45 and
90 min and adding one further measurement at
300 min post-meal. Dogs were fed to meet mainte-
nance requirements (ME, kcal = 132 ·BW
0.75
kg;
National Research Council, 1985), and adapted to
their diets for 3 days before testing. During this per-
iod, they were conditioned to ingest all food within
10 min, once per day. Thereby the animals were
tested after 24 h after last meal. Dogs that took
longer than 10 min to consume their total amount
of food were not tested and the procedure was
repeated the following day. On the day of the test,
each dog was aseptically catheterized using a periph-
eral intravenous catheter inserted into the cephalic
vein (Angiocath 20 GA x 1.16 in., Becton-Dickinson,
Franklin Lakes, NJ, USA). Blood samples were taken
pre-feeding (baseline sample, time 0) and 5, 10, 15,
30, 60, 120, 180, 240 and 300 min post-feeding.
Blood was always collected at the same time, begin-
ning at 10 am. Each sample (3 ml) was collected in a
Na-heparin tube, centrifuged (378 gfor 5 min), and
the plasma separated into two Eppendorf tubes.
Plasma samples for glucose measurement were kept
under refrigeration (4 C) for a maximum of 2 h
before analysis; insulin plasma samples were frozen
()70 C) for a maximum of 2 months before they
were analysed.
Laboratory analyses
At the end of the collection period, faeces were
thawed, homogenized, and pooled by dog. Prior to
performing laboratory tests, faeces were dried in a
forced air oven at 55 C for 72 h (320-SE; FANEM,
Sao Paulo, Brazil) and ground in a cutting mill
with a 1-mm sieve. Food samples were ground in
the same way. Diets and faeces were analysed
according to AOAC (1995) standards for DM by
Table 1 Ingredient composition of experi-
mental dog diets
Ingredients
As-fed basis (%)
Cassava
flour Corn Sorghum
Brewer’s
rice Lentil Pea
Cassava flour 42.49
Corn 53.49 –
Sorghum – 59.27
Brewer’s rice 45.66
Lentil 69.53 –
Pea – 66.35
Poultry by-product meal 24.00 24.00 23.00 24.00 17.70 19.00
Isolated soybean protein 17.01 9.94 5.16 16.08 0.18 0.09
Poultry fat 5.93 2.00 2.00 3.69 2.02 3.99
Dried whole egg 2.50
Soybean hull 2.00
Brewer’s dried yeast 1.50
Dried hydrolyzed bovine liver 1.50
Dicalcium phosphate 0.90
Calcium carbonate 0.70
Potassium chloride 0.40
Sodium chloride 0.40
Chromium oxide 0.35
Vitamin/mineral premix* 0.10
Mold inhibitor0.10
l-lysine 0.06
dl-methionine 0.05
Antioxidantà0.01
*Per kg of diet: iron, 120 mg; copper, 15 mg; magnesium, 75 mg; zinc, 150 mg; iodine, 2 mg;
selenium, 0.3 mg; vitamin A, 18 000 IU; vitamin D
3
, 1 000 IU; vitamin E, 100 IU; vitamin K, 2 mg;
biotin, 0.6 mg; thiamin, 20 mg; riboflavin, 10mg; pantothenic acid, 50 mg; niacin, 75 mg; vitamin
B
6
, 6 mg; folic acid, 4 mg; vitamin B
12
, 0.1 mg.
Mold Zap
: Ammonium dipropionate, acetic acid, sorbic acid and benzoic acid – Alltech do
Brasil Agroindustrial Limited.
àBanox
: BHA-butilated hydroxyanisole; BHT-butilated hydroxytoluene, propyl gallate and
calcium carbonate – Alltech do Brasil Agroindustrial Limited.
Evaluation of carbohydrate sources for dogs A. C. Carciofi et al.
328 Journal of Animal Physiology and Animal Nutrition. ª2008 The Authors. Journal compilation ª2008 Blackwell Publishing Ltd
oven-drying the sample (934.01), ash through muf-
fle furnace incineration (942.05), crude protein
(CP) applying the Kjeldahl’s method (954.01), acid-
hydrolyzed fat (AHF, 954.02), phosphorus (964.06),
and calcium (968.08). Organic matter (OM) was
calculated by difference (OM = 100)DM). Total die-
tary fibre was measured according to Prosky et al.
(1992) and total starch according to Miller (1959)
and Hendrix (1993). Gross energy (GE) content of
diets and faecal matter was determined using a
bomb calorimeter (Model 1261; Parr Instrument
Company, Moline, IL, USA). Fenton and Fenton
(1979) procedure was used to determine chromium
oxide levels through visible spectrophotometry
(U2010
Hitachi SA, Brisbane, CA, USA). All analy-
ses were carried out in duplicate with a coefficient
of variation below 5%.
Plasma glucose concentrations were determined
by glucose oxidase tests (GOD-ANA; Labtest Diag-
no
´stica S.A., Lagoa Santa, Brazil) using a semi-auto-
mated glucose analyser (Labquest model BIO-2000;
Labtest Diagno
´stica S.A.). Plasma insulin was mea-
sured by radioimmunoassay (RIA) using a commer-
cially available kit (I
125
as tracer, human insulin as
standard; Diagnostic Products Corporation, Los
Angeles, CA, USA) that has already been validated
for dogs (Holste et al., 1989). The intra-assay coeffi-
cient of variation for insulin was 8.4% and the stan-
dard error 0.15 lIU/ml.
Calculations
Apparent digestibility coefficients of DM, OM, CP,
AHF, TDF, GE and total starch were calculated for
each experimental diet using chromium as an
indigestible marker, according to Merchen (1988).
Changes in plasma glucose and insulin concentra-
tions were calculated for each post-prandial period.
Responses were compared for average and maximum
increase, average and maximum incremental increase
(the difference between the absolute glucose or insu-
lin concentration sample and the baseline concentra-
tion), and time to peak increase. The integrated area
under post-prandial glucose and insulin response
curves were calculated using the trapezoidal method.
In addition to measuring total area under the curve
(AUC, from 0 to 300 min), immediate meal response
(AUC £30 min) and later meal response (AUC
30 min) were also calculated. origin (Microcal
Software Version 6.0, OriginLab Corporation, MA,
USA) software was used for AUC computing.
Statistical analyses
The experiment was carried out on thirty-six dogs,
with six dogs per diet in a completely randomized
design. Male and female dogs were distributed
among each group and all groups were evaluated
during the same period. Data were analysed using
Table 2 Chemical composition of starch
sources and experimental dog diets (g/kg dry
matter)* Item
Cassava
flour Corn Sorghum
Brewer’s
rice Lentil Pea
Ingredients
Dry matter (g/kg) 893.7 888.3 887.2 888.8 889.4 893.0
Organic matter 999.3 981.4 978.7 970.7 973 981.1
Crude protein 19.4 105.1 109.3 76 232.6 244.9
Fat 2.5 52.0 60.1 38.0 9.0 11.8
Starch 949.5 784 724.3 881.4 552.6 567.0
Total dietary fibre 15.4 40.7 69.1 16.4 141.3 110.1
Soluble dietary fibre 2.0 6.2 13.8 2.3 29.1 24.7
Insoluble dietary fibre 13.4 34.5 55.3 14.1 112.2 85.4
Crude fibre 33.6 13.2 55.3 8.7 69.3 29.3
Diets
Dry matter (g/kg) 909.5 914.3 913.6 915.7 923.1 912.9
Organic matter 920.2 914.1 922.1 917.1 920.5 918.4
Crude protein 318.4 317.6 282.8 371.0 313.7 295.7
Fat 130.8 118.6 99.9 111.8 91.1 110.0
Starch 417.7 379.9 385.1 399.5 384.8 366.0
Nitrogen-free extract 447.8 445.3 511.2 404.3 489.5 484.0
Total dietary fibre 40.6 94.0 141.3 39.8 159.8 147.4
Crude fibre 23.1 32.6 28.2 30.0 26.2 28.7
*All samples were analysed in duplicate with a coefficient of variation of <5%.
Sorghum containing 0.57% tannin (as-fed base).
A. C. Carciofi et al. Evaluation of carbohydrate sources for dogs
Journal of Animal Physiology and Animal Nutrition. ª2008 The Authors. Journal compilation ª2008 Blackwell Publishing Ltd 329
the general linear model functions of sas (Version
8.0, SAS Institute, Cary, NC, USA). The experimen-
tal unit was dog; the model sums of squares were
separated into treatment (diet) and animal effect. All
multiple comparisons of treatment means were made
using Tukey’s test (p < 0.05). Repeated measures
anova was the statistical method chosen to evaluate
the effects of diet and time on post-prandial plasma
changes. Pairwise mean comparisons were also made
through Tukey’s test (p < 0.05). All data were found
to comply with the assumptions of anova models.
Results
Digestibility and faecal characteristics
Diet chemical compositions are presented in Table 2
and daily nutrient intakes, diet digestibilities and
faecal characteristics are presented in Table 3. All
dogs successfully consumed their experimental diets
and there were no episodes of vomiting, diarrhoea
or meal refusal. Variations in TDF, CP and fat
ingestion between diets were verified (p < 0.05)
and can be explained by the differences in diet
composition. Dogs fed sorghum-based diets ingested
more protein than those receiving lentil-based diets
while ingesting less fat than dogs fed the cassava
flour diet (p < 0.05). Ingestion of other nutrients
was not significantly different between diets
(p > 0.05).
Differences in nutrient digestibility were identified.
Digestibility of DM, OM and GE in brewer’s rice and
cassava flour-based diets was higher than in other
diets (p < 0.05). Protein digestibility was higher in
brewer’s rice than sorghum, corn, pea and lentil
diets (p < 0.05). Fat digestibility was greater for cas-
sava flour and pea diets than other treatments
(p < 0.05). Starch digestibility was >98% for all
treatments with brewer’s rice and cassava flour diets
presenting the greatest digestibility, and pea and len-
til diets the least (p < 0.05). Digestibility of TDF in
pea, lentil and sorghum diets was higher than in
corn and cassava flour treatments (p < 0.05), while
for crude fibre digestibility, no differences were
observed among diets (p > 0.05).
No differences were observed in faecal scores
(p > 0.05). Faecal DM was greater for dogs fed
brewer’s rice, sorghum and corn than for those fed
pea-based diet (p < 0.05). Faecal pH was higher for
the rice-based diet than lentil and pea diets
(p < 0.05).
Table 3 Nutrient intake, apparent total tract digestibility and faecal characteristics of dogs fed experimental diets containing different starch
sources*
Item Cassava flour Corn Sorghum Brewer’s rice Lentil Pea
Daily nutrient intake (g/kg body weight /day)
Dry matter 16.3 0.5 15.2 1.5 14.3 0.5 15.2 1.3 18.9 0.5 16.5 0.2
Organic matter 15.0 0.5 13.9 1.4 13.2 0.4 13.9 1.2 17.4 0.5 15.1 0.2
Crude protein 5.0
bc
0.2 4.8
bc
0.5 4.1
c
0.1 5.6
bc
0.5 5.9
b
0.2 4.9
bc
0.1
Starch 6.8 0.2 5.8 0.6 5.5 0.2 6.1 0.5 7.3 0.2 6.0 0.1
Fat 2.1
b
0.1 1.8
bc
0.2 1.4
c
0.1 1.7
bc
0.1 1.7
bc
0.1 1.8
bc
0.1
Total dietary fibre 1.0
de
0.1 1.4
cd
0.1 1.7
c
0.1 0.9
e
0.1 3.0
b
0.1 2.6
b
0.1
Crude fibre 1.9 0.2 2.5 0.2 2.0 0.1 2.3 0.2 2.5 0.1 2.4 0.1
Apparent digestibility coefficients (%)
Dry matter 83.1
b
0.1 78.6
c
0.5 79.0
c
0.3 82.4
b
0. 74.5
d
0.6 76.1
d
0.7
Organic matter 87.7
b
0.1 83.9
c
0.4 83.8
c
0.2 88.4
b
0.2 79.3
d
0.4 80.1
d
0.7
Crude protein 86.8
bc
0.5 86.1
c
0.3 85.0
cd
0.5 89.0
b
0.5 79.9
e
0.7 83.4
d
0.6
Starch 99.4
b
0.1 99.1
bc
0.1 99.1
bc
0.1 99.3
b
0.1 98.8
c
0.2 98.7
c
0.1
Fat 92.8
b
0.2 89.1
cd
0.3 88.3
d
0.1 89.0
cd
0.4 89.4
cd
0.5 90.0
c
0.2
Gross energy 87.8
b
0.1 84.9
c
0.6 84.2
c
0.4 87.7
b
0.4 78.4
e
0.5 80.9
d
0.8
Total dietary fibre 8.2
d
2.2 11.4
d
3.3 27.0
bc
1.4 17.7
cd
0.7 33.4
b
1.7 30.3
b
3.0
Crude fibre 2.6 0.7 3.1 0.3 3.7 0.3 2.6 0.3 5.0 1.2 4.0 0.8
Faecal characteristics
Faecal score4.2 0.1 3.7 0.1 3.8 0.1 4.2 0.1 3.7 0.1 3.7 0.1
Faecal DM (%) 38.6
cd
1.9 40.2
bc
1.2 40.3
bc
1.6 48.5
b
2.6 33.9
cd
2.7 30.9
d
1.4
pH faecal 6.7
bc
0.1 6.5
bcd
0.1 6.7
bc
0.1 7.1
b
0.1 6.0
d
0.1 6.2
cd
0.2
*Values are means SE of the six dogs per diet.
bcde
Within a row, means without a common superscript differ (p <0.05).
Scores: 1 = watery – liquid that can be poured; 2 = soft, unformed – stool assumes shape of container; 3 = soft, formed moist – softer stool that
retains shape; 4 = hard, formed, dry stool – remains firm and soft; 5 = hard, dry pellets – small, hard mass.
Evaluation of carbohydrate sources for dogs A. C. Carciofi et al.
330 Journal of Animal Physiology and Animal Nutrition. ª2008 The Authors. Journal compilation ª2008 Blackwell Publishing Ltd
Post-prandial glucose and insulin responses
Dogs’ post-prandial glycemic and insulinemic
responses are presented in Fig. 1 and Table 4. Mean
plasma glucose concentrations in dogs given cassava
flour and corn-based diets were significantly lower
than those in dogs consuming the other diets
(p < 0.05). Mean incremental glucose response was
higher in dogs given lentil than pea, cassava flour
and corn diets (p < 0.05). Minimum and maximum
incremental rises in glucose concentration were
lower in dogs consuming pea-based diet than the
other five diets (p < 0.05). Maximum glucose con-
centration occurred within the first hour for cassava
flour, corn, brewer’s rice and peas; these diets stim-
ulated glucose peaks significantly earlier than did
the sorghum diet (p < 0.05). Not all post-prandial
glucose response curves returned to baseline during
the observation period (Fig. 1). At 180 min after
consumption of brewer’s rice, cassava flour and
corn diets, mean plasma glucose concentrations
were not significantly different from basal values
(p > 0.05); conversely, after 300 min the plasma
glucose concentrations of dogs given sorghum, pea
and lentil diets remained above basal values
(p < 0.05).
95
Brewer’s rice Cassava flour
Sorghum
Corn
Pea Lentil
90
85
80
75
70
65
60
55
50
55
50
45
40
35
30
25
20
15
10
5
0
55
50
45
40
35
30
25
20
15
10
5
0
55
50
45
40
35
30
25
20
15
10
5
0
55
50
45
40
35
30
25
20
15
10
5
0
55
50
45
40
35
30
25
20
15
10
5
0
55
50
45
40
35
30
25
20
15
10
5
0
95
90
85
80
75
70
65
60
55
50
95
90
85
80
75
70
65
Plasma glucose
concentration (mg/dL)
Plasma glucose
concentration (mg/dL)
Plasma glucose
concentration (mg/dL)
Plasma insulin
concentration (m UI/mL)
Plasma insulin
concentration (m UI/mL)
Plasma insulin
concentration (m UI/mL)
Plasma glucose
concentration (mg/dL)
Plasma glucose
concentration (mg/dL)
Plasma glucose
concentration (mg/dL)
Plasma insulin
concentration (m UI/mL)
Plasma insulin
concentration (m UI/mL)
Plasma insulin
concentration (m UI/mL)
60
55
50
0 30 60 90 120 150 180 210 240 270 300 0 30 60 90 120150 180210 240270 300
0 30 60 90 120 150 180 210 240 270 300 0 30 60 90 120150 180210 240270 300
0 306090
Minutes after meal feeding
Minutes after meal feeding
Minutes after meal feedin
g
Minutes after meal feedin
g
Minutes after meal feeding
Minutes after meal feeding
120 150
Glucose Insulin
Glucose Insulin
Glucose Insulin Glucose Insulin
Glucose Insulin
Glucose Insulin
180 210 240 270 300 0 30 60 90 120150 180210 240270 300
95
90
85
80
75
70
65
60
55
50
95
90
85
80
75
70
65
60
55
50
95
90
85
80
75
70
65
60
55
50
Fig. 1 Plasma glucose and insulin response curves of dogs fed experimental diets containing different starch sources. Values are means SE of
the six dogs per diet. Values significantly higher than baseline for glucose concentrations (p < 0.05). Values significantly higher than baseline for
insulin concentrations (p < 0.05).
A. C. Carciofi et al. Evaluation of carbohydrate sources for dogs
Journal of Animal Physiology and Animal Nutrition. ª2008 The Authors. Journal compilation ª2008 Blackwell Publishing Ltd 331
Total AUC of glucose was greater in lentil than
cassava flour and corn-based diets (p < 0.05). Imme-
diate post-prandial response (AUC £30 min) was
the greatest for brewer’s rice, intermediate for corn,
lentils, peas and cassava flour, and lowest for sor-
ghum (p < 0.05). Regarding later responses, the
AUC 30 min was greater for sorghum, lentil and
pea diets than for brewer’s rice, cassava flour and
corn (p < 0.05).
Mean concentrations of post-prandial insulin were
highest in dogs that had consumed corn-based diet
and lowest for lentil-based diet (p < 0.05). Cassava
flour and brewer’s rice diets induced greater maxi-
mum absolute insulin concentrations than lentils
(p < 0.05), and maximum incremental insulin con-
centration was higher for cassava flour than any
other diet (p < 0.05), although brewer’s rice exhib-
ited intermediate results. Insulin secretion was slow-
est for pea-based diet, which delayed time for
insulin peak in comparison to cassava flour and
brewer’s rice diets (p < 0.05). As Fig. 1 illustrates,
the post-prandial insulin response curve of the sor-
ghum-based diet did not return to baseline during
the 300 min observation period (p < 0.05). Insulin
concentrations had returned to base values by
120 min post-meal for cassava flour diet, 240 min
for brewer’s rice and pea diets, and by 300 min for
corn and lentil diets (p > 0.05).
Total AUC of insulin (0 to 300 min) was smaller
for cassava flour than sorghum (p < 0.05). In the
first 30 min (AUC £30 min) plasma insulin concen-
trations were higher in cassava flour, brewer’s rice
and corn diets than sorghum, lentil and pea diets.
Area under the curve 30 min was greater after
ingestion of sorghum-based diet than either brewer’s
rice or cassava flour based diets (p < 0.05).
Discussion
The greater digestibility of brewer’s rice-based diet in
relation to corn verified in the present study was
also described by Belay et al. (1997), Walker et al.
(1994) and Twomey et al. (2002). The use of sor-
ghum as an ingredient in dog formula was evaluated
by Twomey et al. (2002), who found DM digestibil-
ity comparable in diets using sorghum and brewer’s
Table 4. Medium, maximum, and time to peak plasma glucose and insulin concentrations; medium and maximum incremental glucose and insulin
concentrations; and areas under the absolute and incremental glucose and insulin response curves of dogs fed experimental diets containing dif-
ferent starch sources
a
Diet
Cassava flour Corn Sorghum Brewer’s rice Lentil Pea
Glucose (mg/dl)
Mean concentration 77.4
d
0.8 77.8
cd
0.9 80.5
bc
0.7 79.5
bcd
0.9 81.8
b
0.7 79.6
bcd
0.6
Peak 90.1
bc
1.1 91.9
b
1.1 87.2
bc
0.4 91.6
b
0.6 89.2
bc
0.3 86.7
c
2.1
Mean incremental concentration6.0
c
0.8 5.9
c
0.9 8.3
bc
0.7 7.5
bc
0.9 9.73
b
0.7 5.3
c
0.5
Peak incremental concentration 19.9
b
0.6 20.0
b
1.4 15.1
cd
0.9 19.6
b
1.0 16.9
bc
0.97 12.7
d
0.6
Time to peak (min) 27.5
c
2.5 15.0
c
0.1 160.0
b
36.9 15.0
c
0.1 87.5
bc
20.6 55.0
c
5.0
AUC 0–300 minà(mg/dl min) 23027
c
126 22336
c
807 24271
bc
848 23254
bc
246 25254
b
96 24373
bc
378
AUC £30 min§ (mg/dl min) 2461
c
17 2509
bc
26 2304
e
22 2569
b
16 2434
cd
18 2352
d
37
AUC 30 min(mg/dl min) 20566
c
119 20580
c
221 22893
b
115 20685
c
235 22820
b
86 22020
b
341
Insulin (mg/dl)
Mean concentration 18.5
bc
1.7 20.7
b
1.4 20.3
bc
1.25 19.8
bc
1.5 16.7
c
1.2 19.3
bc
1.3
Peak 43.8
b
1.5 36.8
bcd
2.3 35.5
bcd
1.9 41.1
bc
2.6 31.4
d
1.8 35.0
cd
1.8
Mean incremental concentration 14.9 1.8 15.4 1.4 15.5 1.3 15.7 1.6 11.5 1.2 14.2 1.3
Peak incremental concentration 40.2
b
1.2 31.4
cd
1.9 30.7
cd
2.6 37.0
bc
2.5 26.2
d
1.4 29.9
cd
1.6
Time to peak (min) 27.5
c
2.5 37.5
bc
16.8 105.0
bc
21.6 22.5
c
3.3 100.0
bc
28.6 120.0
b
26.0
AUC 0–300 minà(lIU/ml min) 5582
c
418 6428
bc
439 7749
b
245 6284
bc
550 6364
bc
342 7276
bc
311
AUC £30 min§ (lIU/ml min) 772
b
55 781
b
39 491
c
31 768
b
55 442
c
38 504
c
37
AUC 30 min(lIU/ml min) 4810
d
429 5893
bcd
391 7271
b
256 5515
cd
530 5922
bcd
319 6772
bc
298
AUC, area under the curve.
a
Values are means SE of the six dogs per diet.
bcde
Within a row, means without a common superscript differ (p <0.05).
Incremental concentration = absolute glucose or insulin concentration)basal concentration.
àArea under curve 0 to 300 min.
§Area under curve 0 to 30 min.
Area under curve 30 to 300 min.
Evaluation of carbohydrate sources for dogs A. C. Carciofi et al.
332 Journal of Animal Physiology and Animal Nutrition. ª2008 The Authors. Journal compilation ª2008 Blackwell Publishing Ltd
rice, both being superior to corn-based diet. In a pre-
vious study, however, Twomey et al. (2002) saw les-
ser energy digestibility in sorghum, intermediate
digestibility in corn and greater digestibility in
brewer’s rice. The present research confirmed these
differences between sorghum and brewer’s rice diets,
which can be explained, at least in part, by the addi-
tional quantity of fibre in sorghum. Tannin is
another substance found in sorghum that interacts
with proteins, amino acids, and to a lesser extent
with starch, limiting their digestion (Jansman,
1993). However, the sample used in the present
experiment had such low tannin content (0.57%)
that the presence of the substance did not probably
reduce diet digestibility.
Cassava flour and brewer’s rice within cooked
dog foods were compared by Kamalu (1991), and
as in the present study they encountered similar,
high digestibilities for both diets. No studies on dogs
given pea and/or lentil bean diets were located to
compare and contrast their results, but the lower
digestibilities identified here must be taken into
consideration when creating formulations using
these ingredients. The lower DM digestibilities of
these diets were accompanied by lower protein
digestibilities, verifying the results of other studies
which demonstrated a reduction in protein digest-
ibility in diets with low-digestible carbohydrates
(Murray et al., 1999; Twomey et al., 2002). On
average, pea and lentil diets had TDF digestibilities
2.5 times greater than those of brewer’s rice, corn
and cassava flour. Soluble dietary fibre fractions of
peas and lentils are larger, such that the possibility
exists for greater intestinal fermentation of these
ingredients.
In our investigation, crude fibre was more indi-
gestible than TDF. These results are in assumptions
with others studies about fibre fermentation by dogs,
in vivo (Kienzle et al., 2001) or in vitro models
(Sunvold et al., 1995a,b). Therefore, because of low
digestible nutrients and not veracious amounts of
measurable fibre, crude fibre apparent digestibility
may not be a good method of displaying fibre results
for dogs.
In relation to the starch digestibility of extruded
dog diets, Twomey et al. (2002) also found values
approaching 100%. According to the authors, these
results were because of the extrusion process, which
probably favoured starch gelatinization, making it
almost completely digestible. Bednar et al. (2001)
observed that legumes starches, such as peas and
lentils present reduced digestibility to dogs, a finding
confirmed by the current research. Beyond TDF con-
centration, the authors attributed these differences
between grains and legumes to starch composition;
the proportion of rapidly digestible starch was great-
est in brewer’s rice, corn and sorghum, and lowest
in legumes like peas and lentils.
In the present study, lentil and pea diets produced
lower faecal pH, greater hydrated faeces than rice.
This permits the assumption that for these dogs, a
higher proportion of carbohydrates reached the large
intestine, evidenced by both greater TDF quantities
and lower starch digestibility coefficients, nutrients
which, in turn are made available for bacterial fer-
mentation, according to the assumptions of Cum-
mings and Englyst (1995) and Schu
¨nemann et al.
(1989).
In response to the increase in canine health prob-
lems related to glucose intolerance (e.g. obesity and
diabetes mellitus), an interest has been taken in
investigating diets that favour glycemic control. The
use of starch sources that delay and lengthen glyce-
mic and insulinemic responses while consequently
reducing plasma fluctuations may be beneficial in
these situations (Graham et al., 1994). In this regard,
the present study demonstrated that diets containing
sorghum, lentils or peas could be found to be advan-
tageous over those containing corn, brewer’s rice
and cassava flour.
The interpretation of post-prandial glycemic
responses depends, however, on an integrated evalu-
ation of the diet, one that includes starch-intrinsic
factors like digestion rates and amylose to amylopec-
tin ratios, but also extrinsic influences like ingested
amount, processing and diet composition (Wolever
and Bolognesi, 1996; Heaton et al., 1988; Brand,
1985; Nguyen et al., 1998). In the current study,
diets were formulated to have the closest possible
chemical compositions. Protein intake was sufficient
and variations were small, and according to Nguyen
et al. (1998), differences in the ingestion of this
nutrient do not decisively influence dog post-pran-
dial glucose response, provided that it fulfills the
needs of the animal. Likewise, there were differences
between the fat ingestion of cassava flour and sor-
ghum-based diets. Wolever and Bolognesi (1996)
have already argued that in practical human diets,
the apparent effects of protein and fat on glycemic
response would be negligible. On the other hand,
the quantity of starch ingested by humans corre-
sponds to 46% to 64% of the glycemic variation,
being at times even more important than the type of
starch consumed. In the present study, ingestion of
starch during meal response testing was similar
(p < 0.1) for all dogs.
A. C. Carciofi et al. Evaluation of carbohydrate sources for dogs
Journal of Animal Physiology and Animal Nutrition. ª2008 The Authors. Journal compilation ª2008 Blackwell Publishing Ltd 333
Rice is considered to be a starch source of elevated
glycemic response for humans and canines (Goddard
et al., 1984; Jenkins et al., 1981; Bouchard and
Sunvold, 1999), providing large, rapid alterations in
post-prandial glucose and insulin levels. This charac-
teristic confirmed by the current study is principally
because of the small amount of amylose (Belay
et al., 1997) associated with small quantities of TDF.
The post-prandial response observed in dogs that
consumed cassava flour-based diet also characterized
by rapid rises in glucose and insulin followed by
swift declines back to base levels, may be the result
of an efficient digestibility of extrusion-processed
starch and low-fibre content. Corn diets for dogs
were considered responsible for inducing lower gly-
cemic responses than brewer’s rice (Bouchard and
Sunvold, 1999), a finding that was not confirmed by
this study, as both diets stimulated similar glucose
and insulin responses.
Although corn and sorghum diets presented simi-
lar digestibilities, dogs given these diets experienced
differing post-prandial responses. The major differ-
ences were in relation to time to glucose peak,
which occurred faster for corn, and AUC, which was
greater for corn for the first 30 min and greater for
sorghum for later meal response times. It is worthy
to note that total AUC (0 to 300 min) was similar
for each. According to Rooney and Pflugfelder
(1986), the protein matrix of sorghum’s hard outer
endosperm closely surrounds its starch; this complex
interaction between protein and starch restricts
digestibility.
Dietary fibre content is a further factor that can
alter post-prandial glucose and insulin responses
(Wolever, 1990; Graham et al., 1994). Sorghum,
lentil and pea-based diets provided the highest inges-
tions of TDF, possibly playing a role in delaying and
prolonging the glucose absorption period and in less-
ening the variation in glucose and insulin concentra-
tions demonstrated by these diets in the present
research. Fibre may increase time of gastric emptying
and gastrointestinal transit and diminishes starch
hydrolysis and, consequently, glucose absorption
rate. However, some studies have demonstrated that
in diets with typical fibre levels, variations in the
intake of this ingredient do not significantly influ-
ence post-prandial responses (O’Dea et al., 1980;
Nguyen et al., 1998).
The results reported here indicate that extruded
diets composed of similar ingredients but varying in
starch sources can reveal important differences in
digestibility and post-prandial glycemic and insuline-
mic responses. These differences can be taken into
consideration during the formulation of specialized
products, permitting better technically developed
dog food. Ultimately, long-term studies on the
potential benefits of these carbohydrates are required
for a better understanding of their true effects on
dog health and wellness.
Acknowledgements
The authors acknowledge the financial support of
FAPESP (process 01/08639-3).
References
AAFCO, 2000: Official Publication: Association of
American Feed Control Officials, Atlanta, GA.
AOAC, 1995: Official Methods of Analysis, 15th edn. Associ-
ation of the Official Analytical Chemists, Arlington,
VA.
Bednar, G. E.; Platil, A. R.; Murray, S. M.; Grieshop, C.
M.; Merchen, N. R.; Fahey, G. C. Jr, 2001: Starch and
fiber fractions in selected food and feed ingredients
affect their small intestinal digestibility and ferment-
ability and their large bowel fermentability in vitro in
a canine model. The Journal of Nutrition 131, 276–286.
Belay, T.; Shields-, R. O. Jr; Wiernusz, C. J.; Kigin, P. D.;
Brayman, C. A., 1997: Evaluation of nutrient digestibil-
ity and stool quality of rice (Oryza sativa) based canine
diets. Veterinary Clinical Nutrition 4, 122–129.
Bouchard, G. F.; Sunvold, G. D., 1999: Improving canine
glycemic response to a meal with dietary starch. Pro-
ceedings of the North American Veterinary Conference 1999,
16–19.
Brand, J. C., 1985: Food processing and the glycemic
index. The American Journal of Clinical Nutrition 42,
1192–1196.
Carciofi, A. C.; Vasconcellos, R. S.; de-Oliveira, L. D.;
Brunetto, M. A.; Vale
´rio, A. G.; Bazolli, R. S.; Carrilho,
E. N. V. M.; Prada, F., 2007: Chromic oxide as a digest-
ibility marker for dogs – A comparison of methods of
analysis. Animal Feed Science and Technology 134, 273–
282.
Cummings, J. H.; Englyst, H. N., 1995: Gastrointestinal
effects of food carbohydrate. The American Journal of
Clinical Nutrition 61, 938S–945S.
Fenton, T. W.; Fenton, M., 1979: An improved procedure
for the determination of chromic oxide in feed and
feces. Canadian Journal of Animal Science 59, 631–634.
Goddard, M. S.; Young, G.; Marcus, R., 1984: The effect
of amylose content on insulin and glucose response to
ingested rice. The American Journal of Clinical Nutrition
42, 495–503.
Graham, P. A.; Maskell, I. E.; Nash, A. S., 1994: Canned
high fiber diet and postprandial glycemia in dogs with
Evaluation of carbohydrate sources for dogs A. C. Carciofi et al.
334 Journal of Animal Physiology and Animal Nutrition. ª2008 The Authors. Journal compilation ª2008 Blackwell Publishing Ltd
naturally occurring Diabetes Mellitus. The Journal of
Nutrition 124, 2712–2715.
Heaton, K. W.; Marcus, S. N.; Emmett, P. M.; Bolton, C.
H., 1988: Particle size of wheat, maize, and oat test
meals: effects on plasma glucose and insulin responses
and on the rate of starch digestion in vitro. The Ameri-
can Journal of Clinical Nutrition 47, 675–682.
Hendrix, D. L., 1993: Rapid extraction and analysis of
nonstructural carbohydrates in plant tissues. Crop Sci-
ence 25, 1306–1311.
Holste, L. C.; Nelson, R. W.; Feldman, E. C.; Bottoms, G.
D., 1989: Effect of dry, soft moist, and canned dog
foods on postprandial blood glucose and insulin con-
centrations in healthy dogs. American Journal of Veteri-
nary Research 50, 984–989.
Jansman, A. J. M., 1993: Tannins in feedstuffs for sim-
ple-stomached animals. Nutrition Research Reviews 6,
209–236.
Jenkins, D. J.; Wolever, T. M.; Taylor, R. H.; Barker, H.
M.; Fielden, H.; Baldwin, J. M.; Bowling, A. C.; New-
man, H. C.; Jenkins, A. L.; Goff, D. V., 1981: Glycemic
index of foods: a physiological basis for carbohydrate
exchange. The American Journal of Clinical Nutrition 34,
362–366.
Kahn, S. E.; Prigeon, R. L.; Schwartz, R. S.; Fujimoto, W.
Y.; Knopp, R. H.; Brunzell, J. D.; Porte ., D. Jr, 2001:
Obesity, body fat distribution, insulin sensitivity and
islet b-cell function as explanations for metabolic diver-
sity. The Journal of Nutrition 131, 354S–360S.
Kamalu, B. P., 1991: Digestibility of a nutritionally-bal-
anced cassava (Manihot esculenta Crantz) diet and its
effect on growth in young male dogs. The British Jour-
nal of Nutrition 2, 199–208.
Kienzle, E.; Dobenecker, B.; Eber, S., 2001: Effect of cel-
lulose on the digestibility of high starch versus high fat
diets in dogs. Journal of Animal Physiology and Animal
Nutrition 85, 174–185.
Laflamme, D. P., 1997: Development and validation of a
body condition score system for dogs. Canine Practice
22, 13–18.
Merchen, N. R., 1988: Digestion, absorption and excre-
tion in ruminants. In: D. C. Church (ed.), The Ruminant
Animal: Digestive Physiology and Nutrition. Prentice Hall,
Englewood Cliffs, NJ, pp. 188–189.
Miller, G. L., 1959: Use of dinitrosalicylic acid reagent for
determination of reducing sugar. Analytical Chemistry
31, 426–428.
Murray, S. M.; Fahey, G. C. Jr; Merchen, N. R.; Sunvold,
G. D.; Reinhart, G. A., 1999: Evaluation of selected
high-starch flours as ingredients in canine diets. Jour-
nal of Animal Science 77, 2180–2186.
National Research Council, 1985: Nutrient Requirements of
Dogs. National Academy Press, Washington, USA.
Nguyen, P.; Dumon, H.; Buttin, P.; Martin, L.; Gouro, A.,
1994: Composition of meal influences changes in
postprandial incremental glucose and insulin healthy
dogs. The Journal of Nutrition 124, 2707S–2711S.
Nguyen, P.; Dumon, H.; Biourge, V.; Pouteau, E., 1998:
Glycemic and insulinemic responses after ingestion of
commercial foods in healthy dogs: influence of food
composition. The Journal of Nutrition 128, 2654–2658.
Nishimune, T.; Yakushiji, T.; Sumimoto, T., 1991: Glyce-
mic response and fiber content of some foods. The
American Journal of Clinical Nutrition 54, 414–419.
Nuttall, F. Q.; Moorandian, A. D.; Gannon, M. C.;
Billington, C.; Krezowski, P., 1984: Effect of protein
ingestion on glucose and insulin response to a stan-
dardized oral glucose load. Diabetes Care 7, 465–470.
O’Dea, K.; Nestel, P. J.; Antonoff, L., 1980: Physical fac-
tors influencing postprandial glucose and insulin
responses to starch. The American Journal of Clinical
Nutrition 33, 760–765.
Prosky, L.; Asp, N. G.; Schweizer, T. F.; De Vries, J.
W.; Furda, I., 1992: Determination of insoluble and
soluble dietary fiber in foods and food products: col-
laborative study. Journal of AOAC International 75,
360–367.
Rooney, L. W.; Pflugfelder, R. L., 1986: Factors affecting
starch digestibility with special emphasis on sorghum
and corn. Journal of Animal Science 63, 1607–1623.
Schu
¨nemann, C.; Mu
¨hlum, A.; Junker, S.; Wilfarth, H.;
Meyer, H., 1989: Precaecal and postileal digestibility of
various starches, pH values and concentrations of
organic acids in intestinal chyme. Fortschritte in der
Tierphysiologie und Tiererna
¨hrung 19, 44–58.
Sunvold, G. D.; Fahey, G. C. Jr; Merchen, N. R.; Rein-
hart, G. A., 1995a: In vitro fermentation of selected
fibrous substrates by dog and cat fecal inoculum: influ-
ence of diet composition on substrate organic matter
disappearance and short-chain fatty acid production.
Journal of Animal Science 73, 1110–1122.
Sunvold, G. D.; Fahey, G. C. Jr; Merchen, N. R.; Titge-
meyer, E. C.; Bourquin, L. D.; Bauer, L. L.; Reinhart,
G. A., 1995b: Dietary fiber for dogs IV. In vitro
fermentation of selected fiber sources by dog fecal
inoculum and in vivo digestion and metabolism of
fiber-supplemented diets. Journal of Animal Science 73,
1099–1109.
Svihus, B.; Uhlen, A. K.; Harstad, O. M., 2005: Effect of
starch granule structure, associated components and
processing on nutritive value of cereal starch: a review.
Animal Feed Science and Technology 122, 303–320.
Twomey, L. N.; Pethick, D. W.; Rowe, J. B.; Choct, M.;
Pluske, J. R.; Brown, W.; Laviste, M. C., 2002: The use
of sorghum and corn as alternative to rice in dog foods.
The Journal of Nutrition 132, 1704S–1705S.
Walker, J. A.; Harmon, D. L.; Gross, K. L.; Collings, G. F.,
1994: Evaluation of nutrient utilization in the canine
using the ileal cannulation technique. The Journal of
Nutrition 124, 2672S–2676S.
A. C. Carciofi et al. Evaluation of carbohydrate sources for dogs
Journal of Animal Physiology and Animal Nutrition. ª2008 The Authors. Journal compilation ª2008 Blackwell Publishing Ltd 335
Welch, I. M. C. L.; Hill, B. S. E.; Read, N. W., 1987: Duo-
denal and ileal lipid suppresses postprandial blood glu-
cose and insulin responses in man: possible
implications for the dietary management of diabetes
mellitus. Clinical Science 72, 209–216.
Wolever, T. M. S., 1990: Relationship between dietary
fiber content and composition in foods and the glyce-
mic index. The American Journal of Clinical Nutrition 51,
72–75.
Wolever, T. M. S.; Bolognesi, C., 1996: Prediction of glu-
cose and insulin responses of normal subjects after
consuming mixed meals varying in energy, protein,
fat, carbohydrate and glycemic index. The Journal of
Nutrition 126, 2807–2812.
Wolter, R.; Do Socorro, E. P.; Houdre, C., 1998: Faceal
and ileal digestibility in the dog of diets rich in wheat
or tapioca starch. Recueil de me
´decine ve
´te
´rinaire 174, 45–
55.
Evaluation of carbohydrate sources for dogs A. C. Carciofi et al.
336 Journal of Animal Physiology and Animal Nutrition. ª2008 The Authors. Journal compilation ª2008 Blackwell Publishing Ltd
... The nutritional value of the diet depends on the digestibility of the individual ingredients but interaction between the ingredients may occur (Fontaínhas et al., 1999;Sklan et al., 2004). For example, differences in starch digestibility among different sources may be due to cereal type, protein-starch interactions, physical form of the granule, starch type, digestion inhibitors, and 206 particle size after processing (Carciofi et al., 2008). Because of this, it is necessary to evaluate the digestibility of the diet and not only of the ingredients. ...
... There are different types of foods on the market, whose labels show the concentration of nutrients, 206 particle size after processing (Carciofi et al., 2008). Because of this, it is necessary to evaluate the digestibility of the diet and not only of the ingredients. ...
... Nutrient concentration according to three lines of concentrates for caninesThe apparent digestibility of MO in the present work ranged from 85.6 to 91.19, which is like that reported by some authors.(Carciofi et al., 2008; Matute et al., 2003; Venturini et al., 2018) (Table 5). The above suggests that the MS, MO and PC digestibility of the evaluated feeds correspond to the type of concentrate and what is expected for adult canine diets. On the other hand, Barreno (2018) reports a superior PC digestibility than what was found in this study. Taking into acc ...
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Introduction: Overweight and obesity in schoolchildren is a public health problem that generates metabolic and endocrine alterations in childhood that can persist and worsen in adult life. Objective: The main objective is to determine the prevalence and factors associated with overweight and obesity in schoolchildren aged from 5 to 9 years belonging to two public educational institutions in the rural and urban area of the Risaralda state. Materials and methods: a conducted observational descriptive study was developed, using a cross- cutting quantitative approach in students from 5 to 9 years enrolled in two educational institutions. The study population was 129 enrolled schoolchildren. For data collection, a survey was conducted by parents and / or caregivers and anthropometric data were taken from the schoolchildren. Results: There was a prevalence of childhood obesity corresponding to 13.2% in the rural area. A 5.4% of childhood obesity, was observed in urban area. A 10.1% of overweight was observed in rural area, in the urban area a 10.9% was registered. Regarding factors associated with excess weight, a lower prevalence of active travel to school was found with 19.4% for rural areas and 15.5% for urban areas in overweight and obese schoolchildren. Also, a higher prevalence of carrying foods in lunch box was encountered, corresponding to 34.9% of the analyzed population, and increased practice of school sport in students from urban areas with a prevalence of 24, 8% and higher consumption of foods with high caloric content in schoolchildren with normal weight (p = <0.05). Conclusion: the prevalence of childhood obesity is higher in the urban environment than in the rural environment estimated through the BMI.
... The nutritional value of the diet depends on the digestibility of the individual ingredients but interaction between the ingredients may occur (Fontaínhas et al., 1999;Sklan et al., 2004). For example, differences in starch digestibility among different sources may be due to cereal type, protein-starch interactions, physical form of the granule, starch type, digestion inhibitors, and 206 particle size after processing (Carciofi et al., 2008). Because of this, it is necessary to evaluate the digestibility of the diet and not only of the ingredients. ...
... There are different types of foods on the market, whose labels show the concentration of nutrients, 206 particle size after processing (Carciofi et al., 2008). Because of this, it is necessary to evaluate the digestibility of the diet and not only of the ingredients. ...
... Nutrient concentration according to three lines of concentrates for caninesThe apparent digestibility of MO in the present work ranged from 85.6 to 91.19, which is like that reported by some authors.(Carciofi et al., 2008; Matute et al., 2003; Venturini et al., 2018) (Table 5). The above suggests that the MS, MO and PC digestibility of the evaluated feeds correspond to the type of concentrate and what is expected for adult canine diets. On the other hand, Barreno (2018) reports a superior PC digestibility than what was found in this study. Taking into acc ...
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The academic community of the department of Risaralda, in its permanent interest in evidencing the results of the research processes that are carried out from the Higher Education Institutions and as a product of the VI meeting of researchers of the department of Risaralda held in November 2021 presents its work: “The journey of research as a challenge towards new trends”, which reflects the result of the latest research and advances in different lines of knowledge in Agricultural Sciences, Health Sciences, Social Sciences and Technology and Information Sciences, which seek to solve and meet the demands of the different sectors. This work would not have been possible without the help of each of the teachers, researchers and authors who presented their articles that make up each of the chapters of the book, to them our gratitude for their commitment, dedication and commitment, since their sole purpose is to contribute from the academy and science to scientific and technological development in the search for the solution of problems and thus contribute to transform the reality of our society and communities. We also wish to extend our gratitude to the institutions of the Network that made this publication possible: UTP, UCP, UNAD, UNIREMINGTON; UNISARC, CIAF, Universidad Libre, Uniclaretiana, Fundación Universitaria Comfamiliar and UNIMINUTO, institutions that in one way or another allowed this work to become a reality, which we hope will be of interest to you.
... Cats were fed each dietary treatment for 9-d adaption followed by 5-d total fecal collection. Feces were scored on a 1-5 scale, with 1 representing liquid diarrhea and 5 representing hard pellet-like (Carciofi et al., 2008). A fecal score of 3.5-4 was considered ideal. ...
... During the collection period, all feces and orts were collected daily. The fecal samples were weighed and scored on a 1-5 scale with 0.5 increments [1liquid diarrhea to 5dry hard pellets; (Carciofi et al., 2008)]. A score of 3.5-4.0 ...
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Dried distillers’ grains, co-products from the ethanol industry, may provide sustainable ingredients for pet food. Due to new post-fermentation separation techniques, corn fermented protein (CFP) is higher in protein and lower in fiber compared to traditional dried distillers’ grains, increasing its appeal for inclusion into pet food. Therefore, the objectives of this study were to determine the effects of increasing levels of CFP on stool quality, apparent total tract digestibility (ATTD), and palatability in adult cats. Four extruded diets were fed to 11 adult cats in an incomplete 4x4 replicated Latin square design. The control diet contained 15% soybean meal (0C) and CFP was exchanged for soybean meal at either 5%, 10%, or 15% (5C, 10C, 15C). Cats were fed each dietary treatment for 9-d adaption followed by 5-d total fecal collection. Feces were scored on a 1-5 scale, with 1 representing liquid diarrhea and 5 representing hard pellet-like (Carciofi et al., 2008). A fecal score of 3.5-4 was considered ideal. Titanium dioxide was added to all diets (0.4%) as a marker to estimate digestibility. Data were analyzed using a mixed model in SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and cat and period as random effects. Fecal dry matter percent and dry fecal output were greater (P < 0.05) at elevated levels of CFP. Stool scores were maintained (P > 0.05) throughout treatments (average; 4). Dry matter, organic matter, crude protein, and gross energy ATTD decreased when cats were fed 15C. There was no difference in ATTD of fat or total dietary fiber among treatments. For palatability assessment, cats preferred 5C over 0C but had no preference with increased CFP inclusion. These results suggest that CFP is comparable to SBM but there may be a maximum inclusion level of 10% when fed to cats.
... Gelatinization is described as breakdown of all starch granules by moisture, temperature, pressure and mechanical shear. This gelatinized starch in extruded grains is highly digestible and ranges from 89% to 99% in food products [4] . Due to their important role in the majority of dog diets worldwide, interest in the effects of grains is growing [5] . ...
... Previously, it has been reported that there is no difference in CF digestibility among dog food based on corn, rice and peas [19] . However, in contrast, one study showed that pea diets had the lowest digestibility level [4] . De-Oliveira et al. [19] reported that CF had the lowest apparent digestibility in dogs because there is a significant correlation between fibre intake and faecal fibre excretion in dogs. ...
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This study aimed to compare nutrient digestibility, preference rate, eff ects on stool and cost of grain-inclusive and grain-free dry dog foods. Two dry dog foods with and without grain formulated with poultry meal, barley, rice, corn, peas, carrot, potato flour, whey, fat, vitamin and mineral sources were manufactured. Twelve adult Golden Retriever dogs (age 3-4 years, body weight = 22.5±1.7 kg) were divided into two groups for the digestibility trial. A total of 20 Golden Retriever and Kangal (age 4-5 years, body weight = 35.5±1.9 kg) breed dogs were used for a two-pan preference test. Crude fibre digestibility of grain-free food was significantly lower (P<0.05). There was no diff erence in other nutrient digestibility in foods as determined by total faecal collection method. Presence of grains in food improved the consistency and dry matter of stool(P<0.05). Dogs preferred grain-free food (55.88%) to grain-inclusive food (44.12%) (P<0.05). The manufacturing cost of grain-free food was found to be about three times higher than grain food. The benefits of grain-free dog diets are debated. Th e eff ects of grain and grain-free foods on digestibility, stool parameters and canine health should be demonstrated by further studies. Cost must be calculated to produce reliable and suitable quality dog food with diff erent ingredients. Palatability and intake levels, which are among the most important criteria in dog nutrition, should be determined by preference tests. Keywords: Digestibility level, Faecal consistency, Grain free dog food, Grain inclusive dog food, Preference test
... During the 4-day collection period, dogs remained kenneled to allow for total fecal collection. The fecal samples were weighed and scored on a 1-5 scale with 0.5 increments [1-liquid diarrhea to 5-dry hard pellets (Carciofi et al., 2008)]. A score of 3.5-4.0 ...
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Oral supplementation of β-glucans may be able to improve the health of companion animals. However, little is understood regarding the effects of yeast β-glucan on diet processing and intestinal function. Therefore, the objectives of this research were to determine the carry through of yeast β-glucan during extruded diet production and its impact on diet utilization by dogs. Three diets were formulated to contain increasing levels of a yeast β-glucan blend at 0, 0.012 and 0.023% inclusion. Processing inputs were held constant during extrusion to allow for evaluation of output parameters and physical characteristics of kibble. Yeast β-glucan concentration was analyzed in extruded diets using the glucan enzymatic method, resulting in >100% recovery. Twenty-four Labrador Retrievers were assigned to one of three dietary groups of 8 dogs each with an equal distribution of sex and age. Dogs were fed dietary treatments for 24-d adaption followed by 4-d total fecal collection. Feces were scored on a 1-5 scale, with 1 representing liquid diarrhea and 5 hard pellet-like with a fecal score of 3.5-4 considered ideal. Fresh fecal samples were collected for analysis of short chain fatty acid concentrations. Apparent total tract digestibility was calculated by total fecal collection (TFC) and titanium (TI) marker methods. Data were analyzed using a mixed model procedure in software (version 9.4, SAS Institute, Inc., Cary, NC). Dry bulk density, kibble diameter, and kibble length did not differ among dietary treatments. Intake was similar among dietary treatments (P > 0.05). Dogs required about 26% more food than estimated [130*BWkg 0.75] to maintain body weight among all treatments. Fecal score was not different (P > 0.05) among dietary treatments but was lower than ideal at an average of 2.6. Nutrient digestibility was not affected (P > 0.05) by inclusion of the yeast β-glucan. By method, the TFC procedure resulted in higher (P< 0.05) digestibility values when compared to the TI procedure. In addition, yeast β-glucan did not alter short or branched chain fatty acid proportions. Overall, processing parameters, physical characteristics of kibble, stool quality, nutrient digestibility, and intestinal health in dogs were not affected by the yeast β-glucan blend.
... Gelatinization improved digestibility of tapioca starch but had no effect on digestibility of wheat starch [15]. Peas and lentils had lower digestibility as compared to grains; however, these results were assessed from individual ingredients rather than the finished, final diet [16]. This may be due to the finely ground physical characteristics of the flours utilized in non-traditional diets as compared to traditional. ...
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Starch gelatinization in pet food may be affected by moisture, retention time, and ingredients used. Starch gelatinization has been associated with changes in digestibility but is not well studied using non-traditional ingredients in canine diets. The objective of this research was to examine differences in starch content and gelatinization associated with changes in ingredient profile (traditional vs. non-traditional) and nutrient content requirements associated with differing life stages. Traditional diets (n = 10) utilizing protein sources including chicken, chicken by-product meal, meat and bone meal and plant-based ingredients including rice, barley, oats, and corn were examined in comparison with non-traditional diets (n = 10) utilizing protein sources including alligator, buffalo, venison, kangaroo, squid, quail, rabbit, and salmon along with plant-based ingredients including tapioca, chickpeas, lentils, potato, and pumpkin. Total starch and gelatinized starch (as percent of total diet) were measured with variation due to ingredient type assessed using Student’s t-test in SAS 9.4. Significance was set at p < 0.05. Total starch (as a percent of diet) was higher in traditional diets compared to non-traditional diets formulated for maintenance (p < 0.0032) or all life stages (p < 0.0128). However, starch gelatinization as a proportion of total starch was lower in traditional diets formulated for maintenance (p < 0.0165) and all life stages (p < 0.0220). Total starch and gelatinized starch had a strong negative correlation (r = −0.78; p < 0.01) in diets utilizing traditional ingredients. These novel data reveal important differences between starch content and gelatinization and may impact selection of various ingredient types by pet food manufacturers.
... Fecal samples were used to calculate ATTD of nutrients but also to characterize fecal scores, defecation frequency, dry and wet fecal output, and fecal pH. Upon collection, feces were scored subjectively according to a 5-point scale (1 runny to 5 hard, in 0.5 point increments; Carciofi et al., 2008) then stored in sterile polyethylene bags (Whirl-Pak; Nasco sampling, Madison, WI) and frozen at -20°C for later analysis. Due to their qualitative measurements, fecal scores were evaluated based on frequency of occurrence rather than on average of aggregate scores. ...
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The objective of this work was to evaluate the use of a Torula yeast on diet processing, palatability, and total tract nutrient digestibility in extruded feline diets. Four dietary treatments were compared, differing by protein source: Torula yeast (TY), pea protein concentrate (PP), soybean meal (SM), and chicken meal (CM). Diets were produced using a single-screw extruder under similar processing conditions. Palatability assessment was conducted as a split plate design where both first choice and intake ratio (IR) were determined. Apparent total tract digestibility (ATTD) of nutrients was estimated using Titanium dioxide as an indigestible marker. During diet production, specific mechanical energy (SME) of TY and SM (average of 187 kJ/kg) was greater (P<0.05) than for PP (138 kJ/kg); however, CM was similar to all treatments (167 kJ/kg). Kibble diameter, piece volume, and sectional expansion ratio were greatest for TY (P<0.05). Additionally, both bulk and piece density were lowest (P<0.05) for TY. Kibble hardness was lower for TY and SM (P<0.05; average of 2.10 Newtons) compared to CM and PP (average of 2.90 Newtons). During the palatability trial, TY was chosen first a greater number of times than CM (P<0.05; 36 vs 4, respectively), but differences were not found between TY and PP (25 vs 15, respectively) or TY and SM (24 vs 16, respectively). Cats had a greater IR (P<0.05) of TY compared to CM and PP (0.88 and 0.73, respectively). However, there was no difference in preference between TY and SM. ATTD of dry matter (DM) and organic matter (OM) was greater (P<0.05) for CM (87.43 and 91.34%, respectively) than other treatments. Both DM and OM ATTD of TY were similar (P<0.05) to PP and SM (average of 86.20 and average of 89.76%, respectively). Ash ATTD was greater (P<0.05) for cats fed TY and SM (average of 37.42%), intermediate for PP (32.79%), and lowest for CM (23.97%). Crude protein (CP) ATTD of TY was similar to all other treatments (average of 89.97%), but fat ATTD was lower (P<0.05; 92.52%) than other treatments (93.76 to 94.82%). Gross energy (GE) ATTD was greater (P<0.05) for CM than TY (90.97 vs 90.18%, respectively); however, TY was similar to PP and SM (average of 90.22%). Total dietary fiber (TDF) ATTD was similar between TY and CM (average of 66.20%) and greater (P<0.05) than PP and SM (average of 58.70%). The Torula yeast used in this study facilitated diet formation, increased diet preference, and was highly digestible when fed to cats.
... However, little is known about the impact of raw material particle size on extruded dog diets. Indeed, in published studies, raw material particle size is either not specified or not fully determined [26][27][28][29]. ...
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Meat and bone meal (MBM) is one animal by-product used in pets. This study purposed to provide information on MBM including either coarsely (MBMc) or finely (MBMf) ground with regard to diet digestibility and fecal characteristics in dogs. Three different levels of MBM (6%, 12% and 24%) of each grinding form (MBM6, MBM12 and MBM24) were added to a basic diet. Six Beagle dogs (body weight 16.7 kg ± 0.42) participated in a Latin Square experiment. Each trial began with the animals adapting to the food for a five-day period, followed by five days of fecal collection. The feed particle size had no effect on the apparent digestibility of organic matter, crude protein and crude fat. The fecal score was significantly affected by the particle size × level interaction among treatments (p < 0.0001). It was noted that the different particle sizes or levels of MBM as main effects had no significant effect on the fecal fatty acid concentrations. These findings suggest that using coarse or fine grinding even including MBM up to 24% in dog diets does not affect the apparent digestibility of protein nor fecal quality negatively in our experimental study.
Article
The consumption of readily digestible starch sources, such as corn, can negatively impact endocrine disorders related to hyperglycaemia in predisposing animals. In this sense, starch sources containing slowly digestible and resistant fractions can assist glycemic control. The present study analyzed the postprandial glycemic response and blood variables of rats fed with four extruded diets containing corn, brown rice, sweet potato and pea as the main starch source. Thirty‐two male Wistar rats (90 days old) were divided into groups of eight animals each. The rats received one of the experimental diets for 30 days according to a completely randomised design. The glycemia was measured on the 29th and 30th days. The glycemia measured on the 29th day was analyzed at 0, 30, 60, 120 and 240 min after oral administration of 50% glucose solution. On the 30th day, the same protocol was repeated after providing 3 g of the experimental diet for each animal to obtain the glycemic curve. After the euthanasia on the 30th day, 7 ml of blood was collected via cardiac puncture for glycated haemoglobin (HBA1c), triglycerides, cholesterol, and aspartate and alanine aminotransferases analysis. Diets with pea and sweet potato provided lower glycemic index, average and maximum glycemia, and glycemic increment in relation to the other starch sources (p < 0.05). Animals fed with the corn diet had higher serum concentrations of triglycerides and HBA1c than the other treatments (p < 0.05). Results demonstrated that pea and sweet potato are interesting starch sources for the control of metabolic disorders related to glycemia.
Article
Smarter understanding of diabetes pathophysiology and pharmacology of insulin therapy can lead to better clinical outcomes. Rather than looking for an insulin formulation that is considered “best” for a general population, it could be appropriate to seek the “smart” insulin choice, tailored to the specific clinical situation. Different treatment goals should be considered, with pros and cons to each. Ideally, insulin therapy in most diabetic dogs should mimic a “basal‐bolus” pattern. The “intermediate”‐acting insulin formulations might provide better “bolus” treatment in dogs than the rapid‐acting formulations used in people. In patients with some residual beta cell function such as many diabetic cats, administering only a “basal” insulin might lead to complete normalisation of blood glucose concentrations. Insulin suspensions (neutral protamine Hagedorn, neutral protamine Hagedorn/regular mixes, lente and protamine zinc insulin) as well as insulin glargine U100 and detemir are “intermediate”‐acting formulations that are administered twice daily. For a formulation to be an effective and safe “basal” insulin, its action should be roughly the same every hour of the day. Currently, only insulin glargine U300 and insulin degludec meet this standard in dogs, whereas in cats, insulin glargine U300 is the closest option.
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The study reported compared coefficients of apparent digestibility (CAD) obtained by total collection (TC) and by chromic oxide (Cr2O3) determined by visible absorption spectrometry (VIS) and flame atomic absorption spectrophotometry (FAAS). These quantification methods were also investigated to assess their precision. Nineteen adult dogs housed in individual digestibility cages were fed three commercial diets, each test including five or seven animals. The experiment was carried out in a completely randomized design with three among-subjects factors (foods) and three within-subject factors (methods), and the dogs were the experimental unit. Estimated CAD for all dietary components in the three diets by either chromium quantification methods did not differ and showed fair agreement with TC results (P>0.05). Coefficients of chromic oxide recoveries in feces were 1.06±0.044 and 1.01±0.045 for VIS and FAAS, respectively, values significantly different (P
A collaborative study was conducted to determine the insoluble dietary fiber (IDF), soluble dietary fiber (SDF), and total dietary fiber (TDF) content of food and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that developed for TDF only, which was adopted official final action by AOAC, except for changing the concentration of buffer and base and substituting hydrochloric acid for phosphoric acid. These changes were made to improve the robustness of the method. Duplicate blind samples of soy isolate, white wheat flour, rye bread, potatoes, rice, corn bran, oats, Fabulous Fiber, wheat bran, and a high fiber cereal were analyzed by 13 collaborators. Dietary fiber values (IDF, SDF, and TDF) were calculated as the weight of residue minus the weight of protein and ash. The coefficients of variation (CVs) of both the independent TDF determination and the sum of IDF and SDF were better than 15 and 18%, respectively, with the exception of rice and soy isolate. These 2 foods, however, contained only about 1% TDF. The CVs of the IDF were equally good, except for Fabulous Fiber, for which filtration problems occurred. The CVs for the SDF were somewhat high, but these products had very low SDF content. There was excellent agreement between the TDF determined independently and the TDF determined by summing the IDF and SDF. The method for separate determination of IDF and SDF requires further study. The modifications (changes in concentration of buffer and base and the use of hydrochloric acid instead of phosphoric acid) to the official final action method for TDF have been adopted.
Article
Starch is organized in concentric alternating semi-crystalline and amorphous layers in granules of various sizes within the endosperm. The amount of amylose in starch normally varies between 200 and 300g/kg, but waxy cereals may contain negligible amounts and starch from high-amylose varieties may contain up to 700g amylose/kg. High amylose content is associated with reduced digestibility. Fat and protein are found on the surface of starch granules, and these components may act as physical barriers to digestion. Heat treatment with sufficient water present will cause gelatinisation that will increase susceptibility for starch degradation in the digestive tract, although a linear relationship between extent of gelatinisation due to processing and digestibility has not been found. The low water content during feed processing limits the extent of gelatinisation, but gelatinisation temperature and extent of gelatinisation will be affected by properties of the starch, which in turn may affect digestibility. The effect of starch properties and feed processing on digestion in non-ruminant animals and ruminants are discussed.
Article
Considerable time is necessary to determine the nonstructural carbohydrates (i.e., glucose, fructose, sucrose, starch) in plant tissues and some methods used for this purpose lack specificity. Two steps in such assays typically occupy much of the assay time: sample drying and homogenization/centrifugation. A laboratory method was therefore developed to carry out such assays without either of these steps. The new method involved separation of the ethanol soluble carbohydrates from disks or slices of plant tissue with hot aqueous ethanol and the in situ conversion of starch to glucose by enzymes. The amount of ethanol-soluble sugars and the glucose released from the tissue during the starch digestion were then determined in a microplate assay using an enzyme-coupled colorimetric reaction which was highly spe cific for glucose. The two starch-degrading enzymes (alpha-amylase and amyloglucosidase) and short digestion times (1.5 h) utilized in this method were selected to quantitatively release glucose from the starch in these samples without digesting significant amounts of beta-glucans. Results obtained with this technique were found to compare favorably with those obtained by homogenization of cotton (Gossypium hirsutum L.) leaf tissue. Besides cotton, this method has been successfully used to analyze soluble carbohydrates from a variety of other plant species. By this method it is possible to analyze plant samples two to five times faster than methods which employ sample drying and homogenization.
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A spectrophotometric procedure was developed using ashing at 450 °C followed by acid digestion in beakers and reading the diluted digests at 440 nm. Errors were minimized by use of blanks and maintenance of a constant acid concentration in the diluted digests.