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Ten mature female dogs (19.0 ± 0.4kg) were used in a replicated 5 × 5 Latin Square experiment to determine the feeding value of maize gluten meal (MGM) in a complete food fed to dogs. All foods contained 100g poultry meal/kg and graded levels of MGM (4–320g/kg dry matter) resulting in foods that were 100, 150, 200, 250 and 300g/kg crude protein (CP). Daily dry matter (DM) intake averaged 307 ± 7g/d. An increase in MGM resulted in an increase in faecal moisture from 516 to 575g/kg (linear; P < 0.001) and faecal DM output increased from 24.2 to 32.9g/d (linear; P < 0.001). The coefficient for apparent ileal digestibility (CIAD) of DM decreased from 0.89 to 0.83 (linear; P < 0.001) and the coefficient for apparent total tract digestibility (CTTAD) of DM decreased from 0.92 to 0.89 (linear; P < 0.001) as MGM increased. The coefficient for apparent large intestinal digestibility (CLIAD; 0.29) was not affected by treatment. Faecal excretion of CP increased from 5.6 to 8.1g/d (linear; P < 0.001) as MGM increased. Crude protein CIAD increased from 0.73 to 0.82 (linear; P < 0.002) with increasing MGM whereas, CP CLIAD was not affected by treatment (0.40). Crude protein CTTAD increased from 0.84 to 0.91 (linear; P < 0.001) as MGM increased. Methionine had the highest overall CIAD ranging from 0.92 to 0.93 and threonine had the lowest CIAD ranging from 0.65 to 0.75. These data indicate that MGM is a highly digestible protein source for canine foods with inclusions of 84 to 322g/kg.
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Animal Feed Science and Technology
116 (2004) 239–248
Evaluation of maize gluten meal as a protein
source in canine foods
Ryan M. Yamka, Susanna E. Kitts,
Alma D. True, David L. Harmon
Department of Animal Sciences, University of Kentucky, Lexington, KY, 40546-0215, USA
Received 15 July 2003; received in revised form 10 May 2004; accepted 26 June 2004
Ten mature female dogs (19.0 ±0.4kg) were used in a replicated 5 ×5 Latin Square experiment to
determine the feeding value of maize gluten meal (MGM) in a complete food fed to dogs. All foods
contained100g poultry meal/kg and graded levels of MGM (4–320 g/kg dry matter) resulting in foods
that were 100, 150, 200, 250 and 300 g/kg crude protein (CP). Daily dry matter (DM) intake averaged
307 ±7 g/d. An increase in MGM resulted in an increase in faecal moisture from 516 to 575 g/kg (lin-
ear;P< 0.001)and faecalDM output increasedfrom 24.2to 32.9 g/d(linear; P< 0.001).The coefficient
for apparent ileal digestibility (CIAD) of DM decreased from 0.89 to 0.83 (linear; P< 0.001) and the
coefficient for apparent total tract digestibility (CTTAD) of DM decreased from 0.92 to 0.89 (linear; P
< 0.001) as MGM increased. The coefficient for apparent large intestinal digestibility (CLIAD; 0.29)
was not affected by treatment. Faecal excretion of CP increased from 5.6 to 8.1g/d (linear; P< 0.001)
asMGM increased.Crude protein CIADincreased from0.73 to 0.82(linear; P< 0.002)with increasing
MGMwhereas, CPCLIAD wasnot affectedbytreatment (0.40).Crudeprotein CTTAD increasedfrom
0.84 to 0.91 (linear; P< 0.001) as MGM increased. Methionine had the highest overall CIAD ranging
from 0.92 to 0.93 and threonine had the lowest CIAD ranging from 0.65 to 0.75. These data indicate
that MGM is a highly digestible protein source for canine foods with inclusions of 84 to 322 g/kg.
© 2004 Elsevier B.V. All rights reserved.
Keywords: Amino acids; Digestibility; Dogs; Maize gluten meal
Published as publication no. 03-07-010 of the Kentucky Agr. Exp. Station
Corresponding author. Tel.: +1 859 2577 516; fax: +1 859 2573 412.
E-mail address: (D.L. Harmon).
0377-8401/$ – see front matter © 2004 Elsevier B.V. All rights reserved.
240 R.M. Yamka et al. / Animal Feed Science and Technology 116 (2004) 239–248
1. Introduction
Commercial dry pet foods often contain cereals because of their low cost and as a starch
sourceforextrusionprocessing (Funaba et al., 2002). Maize gluten meal (MGM), a common
protein ingredient found in canine diets, is a by-product from the manufacturing of maize
syrup or starch. It is the dried residue after the removal of bran, germ and starch (Palika,
1996). Maize gluten meal could be an excellent source of protein for dogs, since nearly
600g/kg of the dry matter (DM) is crude protein (CP) and the sulphur amino acids are
highly digestible in other species (Sasse and Baker, 1973).
Littleresearch has beenpublisheddescribing the digestibilityofMGM by non-ruminants.
Maize gluten meal has often been added to broiler chick diets because it is a good source
of both methionine and cysteine and the amino acids are highly available (Sasse and Baker,
1973). Knabe et al. (1989) determined the apparent digestibility of nitrogen and AA in pro-
tein feedstuffs for growing pigs. Of the plant proteins analyzed (including soya bean meal),
MGM was the most digestible foodstuff of plant origin. Apparent nitrogen digestibility
measured at the ileum was 0.88 and 0.92 for the total digestive tract. When MGM was
fed to cats, Funaba et al. (2001) found that the apparent DM digestibility of MGM (0.74)
was comparable with fish meal (0.76). In a second study, Funaba et al. (2002) found that
MGM-based foods had apparent DM and CP digestibilities of 0.72 and 0.70, respectively.
The results of these studies indicate that MGM can be a valuable protein source in non-
ruminant foods; however, no research has been found reporting the value of MGM in canine
Knowledge of the digestible CP and AA of MGM instead of total dietary CP and AA
concentrations may lead to more accurate formulation of canine diets. The hypothesis
was that MGM can be an excellent source of high quality protein across a wide range of
inclusion levels. Therefore the objective of the present study was to determine the apparent
small intestinal digestibility of MGM-containing foods in response to increasing protein
from MGM.
2. Materials and methods
2.1. Dogs
Ten ileally cannulated (Walker et al., 1994) mature female mongrel dogs with body
weightsof 19.0 ±0.4 kg were used to evaluateprotein and AA disappearance atthe terminal
ileumand through thetotaltract. The dogswerelocated in theDivisionofLaboratoryAnimal
Research Facility at the University of Kentucky (Lexington, Kentucky) and were cared for
in accordance with Institutional Animal Care and Use Committee protocols. Dogs were
housed in an environmentally controlled room at 22C with a light:dark cycle of 14:10.
The kennels measure 1m ×1.5 m with vinyl-coated expanded metal flooring sitting 0.2m
above ground. Each kennel was cleaned twice daily following feeding. During this time
dogs were allowed 25min for exercise and socialization. Water was available ad libitum
throughout the experiment.
R.M. Yamka et al. / Animal Feed Science and Technology 116 (2004) 239–248 241
2.2. Feeding and treatments
The ingredient and chemical compositions of each food is presented in Tables 1 and 2.
Each food was extruded, kibbled and formulated in accordance with the Association of
American Feed Control Officials (2002) nutrient guide for dogs and balanced to meet
maintenance requirements (Tables 1 and 2). Differences between the five foods resulted
from varying proportions of MGM. The source of CP was MGM and foods were 100,
150, 200, 250 and 300g CP/kg. Chromic oxide was added to each food at 2g/kg DM to
serve as an indigestible marker to determine digestibility. Each day food was weighed and
divided into two equal portions and fed at 0700 and 1700 in stainless steel bowls. Each
dog was allowed 20min to consume the food. Bowls were removed after 20min and any
food remaining was weighed and recorded. Throughout the experiment, food samples were
collected daily and pooled into plastic collection bags for nutrient content analysis.
2.3. Sampling
The experiment was designed as a replicated 5 ×5 Latin Square. Each experimental
period was 14 d in length. During the first two days of the period, dogs were fed a 1:1
mixture of their current food and their respective next experimental food in order to avoid
meal refusal and gastric upset. Dogs were allowed 6 d for adaptation to each new food.
On the first day of faecal collection (d 7), all faeces were removed from the cages and
discarded prior to 0730. Faecal output was collected from this point on for the next5dat
each mealtime and placed into labeled plastic bags. Samples were frozen (15C), as they
were collected, and pooled by dog within each period.
Table 1
Ingredient composition of maize gluten meal diets fed to dogs to determine intestinal digestibility
Ingredient, g/kg of diet Treatment, g crude protein/kg
100 150 200 250 300
Maize starch 464.7 388.9 315.0 239.9 165.2
Maize gluten meal 4.483.8 163.2 241.8 322.0
Rice, brewers 250.0 250.0 250.0 250.0 250.0
Poultry meal 100.0 100.0 100.0 100.0 100.0
Grease, choice white 94.791.987.284.479.6
Spray-dried egg
Dicalcium phosphate 19.317.816.414.913.5
Soyabean oil
Palatability enhancer
Vitamin-trace mineral – antioxidanta3.
aFormulated to supply at least (g/kg) 0.6 Mg, 1.9 Na, 6.6 K, 7.9 Cl, (mg/kg) 189 Fe, 163 Zn, 12 Cu, 15 Mn,
0.3 Se, 1.5 I, (IU/g) 18.2 vitamin A, 1.0 vitamin D, 0.19 vitamin E, (mg/kg) 0.3 biotin, 1491 choline, 1.9 folic
acid, 62 niacin, 18 pantothenic acid, 8.6 pyridoxine, 8.0 riboflavin, 42 thiamin and 0.13 vitamin B12.
242 R.M. Yamka et al. / Animal Feed Science and Technology 116 (2004) 239–248
Table 2
Chemical composition of maize gluten meal foods (DM)
Item Treatment (g crude protein/kg)
100 150 200 250 300
Dry matter g/kg, DM basis 952.0 947.0 953.0 963.0 963.0
Organic matter 960.0 960.0 957.0 966.0 962.0
Crude protein 109.0 141.0 199.0 248.0 294.0
Crude fat 124.0 126.0 126.0 127.0 127.0
ME, MJ/kg
Crude fibre
Essential amino acids
Leucine 7.713.522.531.039.3
Nonessential amino acids
Alanine 6.810.015.718.724.1
Aspartate 8.310.313.416.120.0
Glutamate 15.523.535.045.358.8
Glycine 7.88.610.311.712.9
Proline 6.19.615.419.224.6
Sampling of digesta from the ileum lasted for 3 d, and started at the completion of the
faecal period. During ileal collection, Bite-not®collars were placed on the dogs after the
morning feeding and removed after the last collection. These collars allowed the dogs to
drink water normally and prevented the removal of their collection bags which are attached
to the cannulas during sampling times. Ileal digesta collection began at 0800 on d 12. Plastic
30mL-Whirl-Pak®collection bags (Nasco, Fort Atkinson, WI) were placed on the animal’s
cannula to collect the ileal digesta. On d 12 and 13 digesta were collected at hours 0800,
1000, 1200, 1400 and 1600. On d 14 samples were collected at hours 0900, 1100, 1300 and
1500. At each collection time samples were weighed, added to a pooled sample (by dog for
each period) and frozen (15C).
2.4. Analyses
After collection faecal and ileal samples were stored frozen (15C) until they were
lyophilized using a Dura-Dry®MP Freeze-Drier (FTS Systems®, Stone Ridge, NY). Dry
R.M. Yamka et al. / Animal Feed Science and Technology 116 (2004) 239–248 243
matter was determined as the difference in sample weight before and after lyophilization.
Faecal samples were then ground through a 0.5 mm screen in a Cyclotec 1093 Sample Mill
(Tecator, Hoganas, Sweden). Ileal samples were ground using a mortar and pestle. Feed
sampleswereground using a blender (Hamilton Beach/Proctor-Silex,Inc., Glen Allen, VA).
The dried and ground samples were then stored in labeled plastic bags at room temperature
until further analysis.
Ileal, faecal and feed samples were dried, ashed and digested, as described by Williams
etal. (1962). The solutions were allowed to settle and wereanalyzed the following day using
a ATI Unicam 99®atomic absorption spectrophotometer (Cambridge, UK) to determine
Cr concentrations in the samples. Protein content (N ×6.25) of the samples was obtained
using a LECO CNS2000 (St. Joseph, MI) nitrogen analyzer.
Samplesof food, ileal and control samples were prepared for amino acid analysis accord-
ing to methods 998.15 (sulphur and regular) and 994.12 (tryptophan) of the Association of
Official Analytical Chemists (1995).A10L aliquot of the resulting solution was deriva-
tized with 6-Aminoquinolyl-N-Hydroxysuccinimidyl carbamate and AA concentration was
determinedbyreversephase liquid chromatography usingMillipore WatersAccQTagSys-
tem, as described by Liu et al. (1995).
2.5. Calculations and statistics
Digestibility was calculated as described by Merchen (1988) using chromium as an
indigestible marker. Digesta flows were adjusted for the amount of marker recovered in the
faeces during the 5-d faecal collection. Digesta flows were calculated by dividing fecal Cr
excretion, g/d, by marker concentration in the digesta sample. The amount of AA supplied
exclusively by MGM was calculated using the amount of AA disappearing from the 100g
CP/kg food which was subtracted from the remaining foods to determine AA disappearance
of MGM supplied AA.
Data were analyzed as a replicated 5 ×5 Latin Square using the General Linear Models
and Regression procedures of SAS (1989). The experimental unit was the dog, the model
included dog, treatment, period (square) and dog (square), and the error was residual er-
ror mean square. Means were separated using polynomial contrasts for linear, quadratic
and cubic effects of MGM inclusion. Differences were considered significant when
P< 0.05.
3. Results
Alldogs remained healthy throughout theexperiment.There were no majordifferencesin
bodyweightduring the experiment (P= 0.361, Table3). Because intakes were adjusted each
period for maintenance of body weight, there were no differences in DM intake (P= 0.518).
Byincreasing the MGM in the foods faecal moisture increased (linear: P< 0.001)and faecal
DM output and ileal DM flow increased linearly (P< 0.001 and P< 0.001, respectively).
Coefficients for small intestinal (CIAD) and total tract (CTTAD) apparent digestibilities
decreased (linear: P< 0.001 and P< 0.001) as MGM increased. The coefficient for large
intestinal apparent digestibility (CLIAD) was not affected by treatment.
244 R.M. Yamka et al. / Animal Feed Science and Technology 116 (2004) 239–248
Table 3
Influence of protein source on dry matter (DM) digestibility in dogs fed increasing concentrations of maize gluten
Item Treatment, g crude protein/kg Contrastsb
100 150 200 250 300 S.E.M.aLinear Quadratic
Body weight, kg 19.418.919.419.018.90.27 0.361 0.820
DMI, g/d 314.5 301.3 310.2 302.3 308.94.89 0.518 0.227
Faecal moisture, g/kg 516.0 534.0 556.0 565.0 575.09.57 0.001 0.403
Faeces, g DM/ d 24.224.929.829.032.91.21 0.001 0.867
Ileal Flow, g DM/ d 34.834.942.342.251.33.11 0.001 0.369
DM digestibility
Small intestine 0.89 0.88 0.86 0.86 0.83 0.097 0.001 0.426
Large intestinec0.29 0.29 0.28 0.28 0.32 0.024 0.533 0.305
Total tract 0.92 0.92 0.90 0.90 0.89 0.005 0.001 0.892
aStandard error of mean n= 10.
bProbability of greater Fvalue.
cPercentage of ileal flow.
Table 4 depicts CP (N ×6.25) digestibilities. As expected, CP intake increased (P<
0.001) with increasing CP concentration. There was also a linear increase (P< 0.001) in CP
faecal excretion and ileal flow of CP (P< 0.002). Crude protein CIAD linearly increased
(P< 0.002) with increasing MGM. Crude protein CLIAD was not affected by treatment.
Crude protein CTTAD increased linearly (P< 0.001) as MGM increased.
AminoacidCIADin cannulated dogs are shown in Table5. Arginine, lysine, methionine,
tryptophan, cysteine and glycine CIAD were not affected by increased MGM. All other
amino acid CIAD increased linearly with increasing MGM. Methionine had the highest
overall CIAD ranging from 0.92 to 0.93. Threonine had the lowest overall CIAD ranging
from 0.65 to 0.75.
Table 4
Influence of protein source on crude protein (CP) digestibility in dogs fed increasing concentrations of maize
gluten meal
Item Treatment, g crude protein/kg Contrastsb
100 150 200 250 300 S.E.M.aLinear Quadratic
CP intake, g/d 33.842.561.975.091.31.13 0.001 0.047
Faeces, g CP/d 0.001 0.289
Ileal flow, g CP/d 9.410.613. 0.002 0.695
CP digestibility
Small intestine 0.73 0.75 0.79 0.82 0.82 0.023 0.002 0.525
Large intestinec0.40 0.38 0.39 0.41 0.45 0.031 0.193 0.275
Total tract 0.84 0.85 0.88 0.90 0.91 0.096 0.001 0.895
aStandard error of mean n= 10.
bProbability of greater Fvalue.
cPercentage of ileal flow.
R.M. Yamka et al. / Animal Feed Science and Technology 116 (2004) 239–248 245
Table 5
Ileal digestibility coefficients of amino acids in cannulated dogs
Item Treatment (g/kg crude protein) Contrastb
100 150 200 250 300 S.E.M.aLinear Quadratic
Essential amino acids
Arginine 0.86 0.85 0.85 0.88 0.86 0.014 0.513 0.684
Histidine 0.75 0.77 0.81 0.84 0.80 0.022 0.021 0.238
Isoleucine 0.79 0.79 0.81 0.83 0.83 0.015 0.014 0.965
Leucine 0.80 0.86 0.89 0.91 0.91 0.012 0.001 0.013
Lysine 0.77 0.77 0.78 0.80 0.76 0.025 0.710 0.515
Methionine 0.97 0.93 0.92 0.93 0.91 0.010 0.187 0.526
Phenylalanine 0.79 0.83 0.86 0.89 0.88 0.015 0.001 0.093
Threonine 0.65 0.66 0.72 0.75 0.74 0.030 0.009 0.510
Tryptophan 0.84 0.81 0.80 0.83 0.77 0.030 0.221 0.848
Valine 0.72 0.74 0.78 0.82 0.80 0.024 0.008 0.374
Nonessential amino acids
Alanine 0.81 0.84 0.88 0.89 0.89 0.013 0.001 0.100
Aspartate 0.68 0.69 0.73 0.76 0.75 0.024 0.006 0.707
Cysteine 0.67 0.70 0.70 0.75 0.72 0.030 0.099 0.468
Glutamate 0.81 0.84 0.87 0.89 0.89 0.012 0.001 0.110
Glycine 0.79 0.76 0.79 0.81 0.78 0.024 0.687 0.805
Proline 0.76 0.81 0.86 0.87 0.87 0.015 0.001 0.040
Serine 0.66 0.70 0.77 0.80 0.80 0.025 0.001 0.249
Tyrosine 0.72 0.79 0.83 0.86 0.86 0.020 0.001 0.050
aStandard error of mean, n= 10.
bProbability of greater Fvalue.
Amino acid CIAD exclusively for MGM are shown in Table 6. This was accomplished
by subtracting the amount of AA supplied in the 100g CP/kg diet since the increases in
CP were all supplied by MGM. Leucine had the highest CIAD (0.98). Tryptophan had the
lowest CIAD (0.60).
4. Discussion
The purpose of this study was to determine the CIAD of protein and AA in canine
foods containing increasing concentrations of MGM as a supplemental protein source. To
our knowledge, no previous research has been conducted to determine AA digestibility
for foods containing graded levels of MGM in dogs. This study showed that MGM is an
excellent source of digestible AA in dogs.
Findings are similar to those found when the digestibility of MGM as a protein source
was determined in pigs (Knabe et al., 1989). In general, Knabe et al. (1989) found that
MGM was highly digestible in pigs, and the protein quality was high. Nitrogen values for
CIAD and CTTAD were 0.88 and 0.92, respectively. However, apparent DM digestibility
was not determined so effects of soluble fibres and other dietary components on CIAD and
CLIAD for DM could not be compared.
246 R.M. Yamka et al. / Animal Feed Science and Technology 116 (2004) 239–248
Table 6
Ileal digestibility coefficients of amino acids supplied by maize gluten meal in cannulated dogsa
Item Maize gluten meal (g/kg)
84 163 242 322 Mean S.E.M.b
Essential amino acids
Arginine 0.86 0.83 0.92 0.87 0.87 0.025
Histidine 0.91 0.88 0.92 0.86 0.89 0.022
Isoleucine 0.94 0.86 0.91 0.82 0.88 0.043
Leucine 0.98 0.98 0.98 0.98 0.98 0.004
Lysine 0.85 0.80 0.87 0.77 0.82 0.038
Methionine 0.89 0.89 0.96 0.90 0.91 0.025
Phenylalanine 0.90 0.84 0.88 0.84 0.87 0.027
Threonine 0.83 0.84 0.88 0.81 0.84 0.020
Tryptophan 0.34 0.57 0.87 0.63 0.60 0.148
Valine 0.94 0.88 0.92 0.88 0.90 0.025
Non-essential amino acids
Alanine 0.97 0.93 0.95 0.93 0.94 0.013
Aspartate 0.85 0.84 0.87 0.82 0.85 0.015
Cysteine 0.92 0.77 0.84 0.76 0.82 0.056
Glutamate 0.96 0.92 0.94 0.92 0.94 0.014
Glycine 0.62 0.84 0.87 0.78 0.78 0.078
Proline 0.94 0.95 0.96 0.94 0.95 0.008
Serine 0.89 0.88 0.92 0.87 0.89 0.014
Tyrosine 0.99 0.96 0.95 0.96 0.96 0.012
aTheamount ofAA supplied exclusively by MGM wasdetermined foreach food. The amount ofAA disappear-
ance from the 100 g CP/kg food was subtracted from the remaining foods in order to determine AA disappearance
of MGM supplied AA.
bStandard error of mean, n= 10.
When MGM was fed to dogs in the present study, CP CIAD ranged from 0.73 to 0.82
and CTTAD ranged from 0.84 to 0.91 (Table 4). The fact that CIAD increased as MGM
concentration increased suggests that MGM is highly digestible in the dog. However, when
CIAD for DM was determined we noticed a slight decrease with increasing inclusions of
MGM. It is unclear why this decrease in digestibility occurred. Since MGM is 600 g CP/kg
it contains a degree of non-protein components. The presence of indigestible sugars and
pectins has been shown to depress digestibility of other plant protein sources; however, no
differenceswere noticed in CLIAD, which would beindicativeof their presence with higher
MGM inclusions. Digestibility of CP could have been lower at the lowest inclusion levels
because endogenous CP excretion would have represented a larger proportion of excreted
CP at these lower inclusion levels. That is a disadvantage of treatments changing in CP con-
tent; however, to balance CP would have required addition of multiple ingredients making
the evaluation of MGM more difficult. The comparatively small changes in faecal CP excre-
tion, (approximately 2g/d) compared with the larger changes in CP intake (approximately
60 g/d) indicate that changes in endogenous secretion with increasing CP intake were prob-
ably small and supports this experimental approach for the evaluation of a single protein
R.M. Yamka et al. / Animal Feed Science and Technology 116 (2004) 239–248 247
The present study indicates that MGM supplemented to poultry meal at an inclusion of
4.4 g/kg (100g CP/kg food) of the food can supply adequate amounts of digestible methio-
nine, tryptophan, leucine, histidine, arginine, and lysine when compared to NRC (1985)
requirements for adult canine maintenance. However, inadequate amounts of digestible
isoleucine, threonine, phenylalanine and valine were supplied by the 100 g CP/kg food. The
maintenance requirements for isoleucine, phenylalanine, threonine and valine were not met
until MGM was supplemented as 83.8g/kg (150 g CP/kg) of the food.
If the difference in AA digestibility between the 100g MGM/kg food and the remaining
foodsare determined, theapparentAA digestibility ofMGM(Table6) canbecalculated. The
AA CIAD of MGM in dogs ranged from 0.60 (tryptophan) to 0.98 (leucine). These findings
are generally in agreement with Knabe et al. (1989), when MGM was fed to pigs. Knabe
et al. (1989) determined that phenylalanine and leucine had the highest digestibilities (0.96
for both) of the essential AA studied. In the dog leucine CIAD was also highest; however,
phenylalanine was lower (0.87). Lysine CIAD were similar between the pig and dog (0.80
versus 0.82, respectively) whereas tryptophan tended to be lower in the dog (0.60 versus
0.72). The foods utilized in the present study did not have MGM as the only protein source.
They also contained brewer’s rice at dietary inclusions of 250 g brewer’s rice/kg in each
food. Brewer’s rice is also a source of protein and AA, is highly digestible and contains
75g CP/kg on a DM basis. Brewer’s rice contributed < 20 g of total protein/kg and thus
contributed from 0.067 to 0.20 of the total CP.
Althoughnopreviousresearch hasevaluatedMGM for dogs the digestibility of SBMand
other plant by-products have been studied extensively in dogs. Kendall and Holme (1982)
determined the digestibilities of SBM and various plant by-products; it was concluded
that soya bean products had a higher apparent digestibility when compared to other plant
by-products. However, MGM was not utilized in the experiment.
Zuo et al. (1996) compared the digestibilities of low oligosaccharide SBM and SBM to
poultry meal (PM) in ileal cannulated dogs. The CIAD and CTTAD for DM for all foods
ranged from 0.59 to 0.62 and 0.76 to 0.80, respectively. Crude protein CIAD and CTTAD
for all foods ranged from 0.68 to 0.78 and from 0.80 to 0.84, respectively. In the present
study, MGM CIAD and CLIAD for DM ranged from 0.83 to 0.89 and 0.89 to 0.92. Crude
protein CIAD and CLIAD ranged from 0.73 to 0.83 and 0.84 to 0.91, respectively. When
compared to the SBM used by Zuo et al. (1996), MGM has a higher overall digestibility.
The difference in digestibilities amongst the two protein sources could be the result of lower
fibre levels and lack of indigestible sugars and complexes that are commonly associated
with SBM (indigestible oligosaccharides, phytate, etc.). Approximately 200g/kg DM of
MGM is starch which has been shown to be highly digestible (>0.90) in dogs (Murray
et al., 1999). However, comparisons between studies may be difficult because of different
sources of maize starch and dogs utilized in each experiment.
Maize gluten meal is a comparable protein source to PM when comparing data from
the present study to a previous study investigating the nutritional value of PM as a protein
source in canine foods (Yamka et al., 2003). The average CIAD for DM (0.88) and CP
(0.78) of PM observed by Yamka et al. (2003) are similar to the average CIAD for DM
(0.87) and CP (0.78) of MGM.
In summary, the digestibility of MGM was investigated by adding increasing amounts
of MGM in the food. Maize gluten meal is highly digestible and the protein quality is high.
248 R.M. Yamka et al. / Animal Feed Science and Technology 116 (2004) 239–248
The CP and AA digestibility increased with increasing dietary MGM indicating MGM can
be an effective protein source at various percentages of the overall food. This information
can be utilized to more accurately formulate canine foods containing MGM.
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... Breed, or more importantly size of dog has been extensively studied in regards to digestibility. Comparisons of Beagles and Great Danes indicated that digestibilities of crude protein, fiber and NFE were lower in the Great Danes (Zentek & Meyer, 1995). This is in contrast to early work suggesting no effect of breed on digestibilities in dogs (James & McCay, 1950 et al., 1999). ...
... In our studies, e.g. (Yamka et al., 2003a;Yamka et al., 2003b;Yamka et al., 2004;Yamka et al., 2005b;Yamka et al., 2005a) we also correct for fecal recovery of Cr 2 O 3 , i.e. Cr intake is equated to Cr excretion determined from multiple day fecal collections. ...
... Only isoleucine (increased) and tryptophan (decreased) had linear relationships with dietary crude protein content . When a similar experimental approach was used in the evaluation of corn gluten meal (Yamka et al., 2004), apparent small intestinal digestibility of histidine, isoleucine, leucine, phenylalanine and valine all increased linearly with increasing corn gluten meal (10 to 30 % crude protein) in the food. Only leucine also had significant quadratic effects. ...
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This review covers methods that have been applied to study the nutrient value or quality of specific ingredients fed to dogs, cats and comparable species (i.e. foxes, minks, rats, etc.). Typically, the nutritional value or utilization of a specific ingredient is measured by total tract digestibility and has been expanded through the measurement of total nutrient balance (i.e. nitrogen or energy). However, to better understand digestion it is necessary to obtain a more accurate measurement of nutrients entering and leaving the small intestine. Accurate measurement of small intestinal digestion is crucial in dogs and cats because nutrient digestion and absorption occurs primarily in the small intestine. Measuring small intestinal digestibility requires access to digesta leaving the small intestine and can be obtained by placing a cannula at the terminal ileum. This approach also necessitates the use of markers (e.g. chromic oxide) to monitor flow of digesta. Specifically, this approach has been used for the direct measurement of intestinal digestion of carbohydrates and amino acids. It also permits a separate measurement of large intestinal digestion which is particularly useful for the study of fiber fermentation. Passage of foods through the gastrointestinal tract is also an important component of utilization and these methods are reviewed.
... There are no other reports on the inclusion of wheat gluten in dog diets, but it has been included in diets for weanling pigs with excellent results (Richert et al., 1994). a highly digestible plant protein suitable for inclusion in diets for dogs (Yamka et al., 2004). Maize gluten meal is a by-product of the manufacture of maize syrup and maize starch, and consists of the dried residue that remains after removal of the bran, germ and starch from maize. ...
... Maize gluten meal is a by-product of the manufacture of maize syrup and maize starch, and consists of the dried residue that remains after removal of the bran, germ and starch from maize. Maize gluten meal is high in protein (60% CP) and when it was fed to dogs, the apparent CP digestibility improved as the inclusion level increased (Yamka et al., 2004). The inclusion levels tested ranged from 84-322 g/kg and the total tract CP digestibility increased from 84-91%. ...
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Many dog owners wish to feed their dogs a vegetarian diet for the same ethical reason that they themselves are vegetarian. To meet this demand, there are an increasing number of vegetarian diets and recipes available for dogs. However, proof for their claims of nutritional adequacy is often lacking. There is little doubt that a dog’s nutritional requirements can be met from a diet that does not contain meat; however, the difference between the amino acid profiles of plant and animal proteins must be considered. It has been shown that exercising dogs may develop anaemia when fed unbalanced plant- protein diets but will remain in good health if the meat- free diet is correctly balanced. Many plant ingredients contain high levels of non-starch polysaccharides and other anti-nutritive factors, which may reduce the availability of some nutrients. A diet devoid of animal ingredients is also likely to be of low palatability to dogs. All diets should be correctly formulated to meet nutrient requirements based on chemical analysis and predicted or measured apparent digestibility, should be sufficiently palatable to ensure adequate dietary intake and should maintain good health when consumed. If a vegetarian diet meets all of these criteria, then it is a suitable diet for the dog, irrespective of the owner’s motivation for feeding a vegetarian diet.
... Some of these protein sources have been evaluated in an animal model (Johnson et al., 1998;Yamka et al., 2003Yamka et al., , 2004Dust et al., 2005). However, technology and material composition have changed over time. ...
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New protein ingredients are used to support pet food market growth and the development of new products while maintaining animal dietary needs. However, novel protein sources (e.g., spray-dried chicken, and (or) rice, pea, and potato protein concentrates) have limited data available regarding their protein quality. The objective of this study was to evaluate protein ingredients used in the pet food industry by laboratory analysis and a chick growth assay as a model. Following analysis for proximate and amino acid composition, chicks (six birds per pen with four pens per treatment) were fed experimental diets for 10 d. Diets contained 10% crude protein from each of the experimental protein sources (spray-dried egg-SDEG; spray-dried egg white-SDEW, spray-dried inedible whole egg-SDIE, chicken by-product meal-CBPM, chicken meal-CKML, low-temperature fluid bed air-dried chicken-LTCK, low-temperature and pressure fluid bed dried chicken-LTPC, spray-dried chicken-SDCK, whey protein concentrate-WPCT, corn gluten meal-CGML, corn protein concentrate-CPCT, potato protein isolate-PPIS, rice protein concentrate-RPCT, pea protein isolate-PEPI, soy protein isolate-SPIS, and soybean meal-SBML) along with an N-free diet (negative control). Chicks fed SDEG, SDIE, and LTPC had the highest protein efficiency ratio (PER; P < 0.0001; 5.18, 5.37, and 5.33, respectively), LTCK and SDCK were intermediate (4.54 and 4.79), and the CBPM and CKML were the lowest among the poultry proteins for EAA:NEAA, PER, and Lys availability. Among the vegetable proteins, PPIS and SBML had the highest PER values (3.60 and 3.48, P < 0.0001). In general, the chick PER method ranked the quality of animal protein sources higher than vegetable proteins, and these results were consistent with the EAA:NEAA ratio and Lys availability.
... Os ingredientes protéicos de origem animal possuem melhores balanços de aminoácidos essenciais que os de origem vegetal para cães e gatos (NEIRINCK et al., 1991;CLAPPER et al., 2001). Contudo, a literatura revela grande diferença de resultados entre experimentos quanto à qualidade e digestibilidade de farinhas de subprodutos de origem animal SHILEY & PARSONS, 2001; O farelo de glúten de milho 60% é considerado uma boa fonte protéica para gatos e cães, sendo sua digestibilidade igual ou superior à de diversos ingredientes de origem animal FUNABA et al., 2001FUNABA et al., , 2002FUNABA et al., , 2005YAMKA et al., 2004;. Apesar de ser deficiente em alguns aminoácidos essenciais, sua proteína é rica em aminoácidos sulfurados, como a metionina, o que é especialmente importante para felinos, que apresentam elevada necessidade deste nutriente e também por seu papel importante na acidificação do pH urinário (FUNABA et al., 2001;. ...
... Age-related diseases such as diabetes and renal, cardiovascular and neurodegenerative diseases are also seen in dogs, showing many similarities to these diseases in humans (83 -85) . RAGE are reported in dogs (86) , and several studies have been conducted indicating that AGE also accumulate by binding to tissue proteins of ageing and diseased dogs. Comazzi et al. (87) reported higher AGE in plasma from dogs suffering from canine diabetes mellitus compared with control (13) . ...
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The Maillard reaction, which can occur during heat processing of pet foods or ingredients, is known to reduce the bioavailability of essential amino acids such as lysine due to the formation of early and advanced Maillard reaction products (MRP) that are unavailable for utilisation by the body. Determination of the difference between total and reactive lysine by chemical methods provides an indication of the amount of early MRP present in foods, feeds and ingredients. Previous research reported that the difference between total and reactive lysine in pet foods can be up to 61·8 %, and foods for growing dogs may be at risk of supplying less lysine than the animal may require. The endogenous analogues of advanced MRP, advanced glycation endproducts, have been associated with age-related diseases in humans, such as diabetes and impaired renal function. It is unknown to what extent advanced MRP are present in pet foods, and if dietary MRP can be associated with the development of diseases such as diabetes and impaired renal function in pet animals. Avoidance of ingredients with high levels of MRP and processing conditions known to favour the Maillard reaction may be useful strategies to prevent the formation of MRP in manufactured pet food. Future work should further focus on understanding the effects of ingredient choice and processing conditions on the formation of early and advanced MRP, and possible effects on animal health.
... Distillers dried grains with solubles and CPP 392to further break down proteins to small peptides (di-or tripeptides) or free AAs that can be 400 absorbed by the brush-border membrane of the enterocytes. 401In digestibility studies, apparent ileal CP digestibility by adult dogs of CGlM was 402 reported to be 73 to 83% byYamka et al. (2004). In the present study, CP disappearance of 403CGlM was greater (94.1%). ...
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The objectives of this study were to determine the chemical composition and nutritive value of corn protein product 1 (CPP 1), corn protein product 2 (CPP 2), and corn fiber (CF), novel coproducts of the ethanol industry, and compare these feed ingredients with standard plant protein ingredients [soybean meal (SBM), distillers dried grains with solubles (DDGS), corn gluten meal (CGlM), and corn germ meal (CGeM)], and to compare CF sources (CF control 1 and control 2) with standard fiber sources (peanut hulls, Solka-Floc, and beet pulp) commonly used in pet foods. Corn fiber, CPP 1, and CPP 2 were produced at a pilot-scale modified dry-grind plant, with CPP 2 having a greater degree of purification than CPP 1. Crude protein values for CPP 2 and CPP 1 were 57.3 and 49.7%, respectively. Total dietary fiber concentration was 29% for CPP 2 and 23.5% for CPP 1. Acid-hydrolyzed fat and GE concentrations were similar for these ingredients. In a protein efficiency ratio assay, no differences (P > 0.05) in feed intake, BW gain, or CP intake were noted for CPP 2, CPP 1, or CGlM. However, feeding CPP 2 resulted in a greater (P < 0.05) G:F ratio and protein efficiency ratio than CPP 1 and CGlM. In a cecectomized rooster assay, CGlM had numerically the greatest standardized total AA, total essential AA, and total nonessential AA digestibilities, but they were not different (P > 0.05) from CPP 1 or SBM values. Corn germ meal resulted in the least values, but they were not different from those for DDGS and CPP 1. The greatest values for true nitrogen-corrected ME were obtained with CGlM, followed by CPP 2, DDGS, CPP 1, SBM, and CGeM. Distillers dried grains with solubles and CPP 1 had similar true nitrogen-corrected ME values, and they were not different from values for CPP 2 and SBM. In vitro CP disappearance was greatest (P < 0.05) for CGlM (94.1%), intermediate for DDGS (76.8%) and CPP 1 (77.5%), and least for CPP 2 (74.1%) and CGeM (67.7%). Corn fibers contained predominantly insoluble dietary fiber (1% or less of soluble dietary fiber), with a moderate CP concentration. In vitro OM disappearance for the fiber sources, when using inoculum from dog feces, revealed that with the exception of beet pulp, which had a moderate disappearance value after 16 h of fermentation (17.7%), all fiber substrates had a nonsignificant extent of fermentation. In conclusion, novel corn coproducts had properties comparable with the standard protein and fiber sources used in animal nutrition.
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Nine mature mongrel dogs were used to evaluate a surgical technique for the cannulation of the terminal ileum and used in two experiments to determine the effect of carbohydrate source on starch and dry matter digestion. Dogs (16.2 +/- 2.0 kg body weight; means +/- SD) were fitted with an ileal T-cannula constructed of polyvinyl chloride pipe. The cannula was inserted into the terminal ileum approximately 10 cm proximal to the ileocecal junction and the cannula was exteriorized through a small incision on the right flank. Dogs recovered quickly from surgery (5d). A preliminary study using Cr:EDTA in the food indicated that sampling for 12 h postprandially allowed near complete representation of digesta flow for a meal; peak flow occurred 4-to 8-h postfeeding. Two experiments were performed evaluating the effect of carbohydrate source on ileal starch and dry matter digestibility. Dogs were fed two meals daily with Cr2O3 used as a digesta marker. Diets contained 67% extruded grain (corn, rice, oats or barley) and 33% canned meat supplement on a dry matter basis. Starch digestion was complete (> 98%) within the small intestine and was unaffected by carbohydrate source. In experiment 1, prececal and total tract dry matter digestibilities were higher for rice than corn, and in experiment 2, barley was higher than oats. The ileal T-cannula allows for measurement of small intestinal nutrient disappearance without the confounding effects of colonic microflora. This method may be useful when applied to the study of other nutrients in dogs.
A study of a new amino acid analysis method using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate as a precolumn derivatization reagent for the analysis of food and feed is described. All amino acids, including methionine sulfone and cysteic acid, were well separated on a liquid chromatographic system using the optimized chromatographic conditions. Salts in food and feed interfered very slightly with the derivatization yields of all amino acids. Several typical agricultural products and animal feeds, including 2 AOAC test samples, were analyzed with the method. The results agreed well with the data generated by using the classical postcolumn method with ion-exchange chromatography. The average relative standard deviations for corn and broiler starter feed were 0.74 and 0.70%, respectively. Good recoveries of all amino acids were demonstrated (average, 101%), even for a sample with a very complex matrix.
A rapid and accurate atomic absorption method for the determination of chromium in faeces samples from pasture experiments using chromic oxide ‘markers’ is described. Of the elements present after ashing and digesting the samples in a phosphoric acid—manganese sulphate—potassium bromate solution silicate, aluminium, calcium and magnesium were found to interfere in the determination. The effects of these interferences were overcome by the addition of calcium to the test solution and by the addition of silicate to the standards, which were prepared in ‘blank’ solutions. The sensitivities of a number of alternate chromium resonance lines relative to that of Cr 3578·7 Å. are given. These lines may be used to increase the concentration range of the analysis. The results of a comparison of the atomic absorption method with a chemical method are given.
The apparent digestibility of 21 plant materials was evaluated in dog diets using adult beagles. In most cases the digestibility by difference method was used. Apparent crude protein (N × 6.25) digestibility coefficients for textured soya protein, extracted soya meal, full-fat soya flours and micronised whole soya beans ranged from 0.71 to 0.87. Digestible energy (DE) contents ranged from 14.3 to 20.8 MJ kg DM−1. Samples of wholeground wheat, barley meal and flaked maize were well digested by dogs, as were samples of refined flour, vital gluten, feeding-oat meal and wheat-germ meal; apparent energy digestibility coefficients ranged from 0.72 to 0.96. Wheatfeed and two distillers by-products had lower energy digestibility coefficients (0.39 to 0.59). Other materials with low apparent digestibility in dog diets (probably because of high fibre levels) were walnut meal, almond meal, dried molassed sugar beet pulp and locust bean meal. Gross energy and dry matter digestibility coefficients of below 0.52 were obtained. Data are also presented on the digestibility of samples of rapeseed meal, cassava and dried potato. When comparison was possible, DE values measured for dogs agreed closely with those for pigs for most materials.
Eight digestion trials were conducted with pigs fitted with ileal T-cannulas to determine the apparent digestibilities of N and amino acids in common protein feedstuffs. Trial-to-trial variation was minimal as determined by the variation in digestibilities for soybean meal, which was evaluated in each trial. Apparent digestibilities varied widely; ileal N digestibility ranged from 88 to 63%, and ileal lysine digestibility ranged from 93 to 40%. In general, ring-dried blood meal, corn gluten meal, Menhaden fish meal, poultry-by-product meal and extruded whole soybeans were the most digestible, followed by canola meal, sunflower meal, peanut meal and meat and bone meal. Cottonseed meal and feather meal were the least digestible. Mean values for each feedstuff agree well with published data. Variation in digestibilities among samples of the same feedstuff was greater for the meat and bone meals. Regression of ileal essential amino acid digestibilities on ileal and fecal N digestibility indicated that amino acid digestibilities can be predicted more precisely from ileal N digestibility than from fecal N digestibility. However, neither ileal nor fecal N digestibility could be used with a high degree of certainty to predict ileal amino acid digestibilities.
We investigated digestion responses to conventional and low oligosaccharide soybean meal (SBM) incorporation into diets for dogs. Five female dogs were fitted with T-type cannulas at the terminal ileum and fed five diets in a 5 x 5 Latin square design. Corn grain + poultry meal-based diets containing different levels and types of SBM (0% SBM, 18.55% conventional SBM, 18.55% low oligosaccharide SBM, 37.1% conventional SBM, 37.1% low oligosaccharide SBM) were formulated. Each period consisted of 11 d (7-d diet adaptation; 4-d collection of ileal digesta and feces). Intakes of DM, OM, CP, fat, and GE were not affected (P > .10) by treatment. Higher (P < .01) starch intakes and higher (P < .05) total dietary fiber (TDF) intakes were noted for dogs fed diets with SBM. Digestibilities of CP (P < .04) and starch (P < .002) at the ileum were higher for dogs fed the higher levels of SBM. Ileal digestibilities of most individual amino acids followed the CP response. Total tract digestibility of CP was higher (P < .006) in dogs fed the SBM diets. There were no significant differences in nutrient digestibilities between conventional and low oligosaccharide SBM. Stachyose and raffinose intakes by dogs were decreased dramatically (P < .001) as a result of substituting the low oligosaccharide SBM for conventional SBM at the higher dietary concentration, although sucrose intake by dogs fed low oligosaccharide SBM was higher (P < .001). Galactinol was present in low oligosaccharide SBM but not in conventional SBM. Total tract digestion of all oligosaccharides was near 100%. The low oligosaccharide SBM was digested as extensively, but no better than, conventional SBM.
Cereal grains represent 30 to 60% of the DM of many companion animal diets. Once incorporated into a diet, the starch component of these grains can provide an excellent source of ME. However, crystallinity and form of starch are variable and can cause incomplete digestion within the gastrointestinal tract. Diets fed in this experiment included one of six high-starch flours as the main source of carbohydrate. The flours originated from barley, corn, potato, rice, sorghum, and wheat. The diets were extruded and kibbled. Starch fraction concentrations of flours consisted of nearly 100% rapidly digestible starch (RDS) and slowly digestible starch (SDS) combined. Starch fraction concentrations of diets paralleled concentrations in flours. Flours varied widely in concentrations of CP, fat, starch, and total dietary fiber. Ileal OM and CP digestibilities were lowest for the potato flour treatment (74 and 64%, respectively). Ileal and total tract starch digestibilities were different (P<.05) among treatments; however, the starch component of all diets was nearly completely digested (>99%). Total tract digestibility of DM and OM was lowest for sorghum (80 and 84%, respectively) compared to all other diets. Crude protein digestibility was highest for corn (87%). Wet fecal weights tended (P<.08) to be greatest for dogs fed the barley treatment (175 g/d). However, dry fecal weights (dried at 55 degrees C) were greatest for dogs consuming the sorghum diet (51 g/d). Fecal scores were consistently greater (i.e., looser stools) for the barley treatment. Any of these flours could be used without negative effects on digestion at either the ileum or in the total tract. Fecal consistency data for dogs consuming the barley treatment indicate that diets containing large amounts (>50%) of barley may not be advantageous for dog owners who house their animals indoors for most of the day.