Effects of inclusion of poultry by-product meal and enzyme-prebiotic supplementation in grower diets on performance and feed digestibility of broilers

Abstract

1. Two experiments were conducted to determine the effects of level of inclusion of poultry by-product and enzyme-prebiotic supplementation on grower diet digestibility and the performance of broilers. 2. Six grower diets were formulated to provide a similar nutrient profile with the exception of using three graded levels of poultry by-product, namely 0, 25, 40 g/kg of the diet with and without supplementation of enzyme preparation at the rate of 1 kg per tonne of feed and prebiotic preparation at the rate of 2 kg per tonne of feed. The experimental diets were used from 3 to 6 weeks of age. 3. Body weights, feed intake and feed conversion efficiency were not affected by poultry by-product; however, enzyme-prebiotic had a significant positive effect on feed conversion efficiency at 0 to 6 weeks in experiment 1. 4. Crude protein digestibility was decreased by feeding the diet containing poultry by-product while ether extract digestibility was increased by poultry by-product at the rate of 25 g per kg of feed only. Dry matter retention, crude fibre digestibility and organic matter retention were not affected by poultry by-product. Dry matter and organic matter retentions, crude protein, ether extract and crude fibre digestibilities were not affected by enzyme-prebiotic. 5. Protein efficiency ratio (PER) values were increased by poultry by-product at the rate of 40 g per kg of feed and addition of enzyme-prebiotic.

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British Poultry Science
ISSN: 0007-1668 (Print) 1466-1799 (Online) Journal homepage: http://www.tandfonline.com/loi/cbps20
Effects of inclusion of poultry by-product meal and
enzyme-prebiotic supplementation in grower diets
on performance and feed digestibility of broilers
F. Kirkpinar , Z. Açikgöz , M. Bozkurt & V. Ayhan
To cite this article: F. Kirkpinar , Z. Açikgöz , M. Bozkurt & V. Ayhan (2004) Effects of
inclusion of poultry by-product meal and enzyme-prebiotic supplementation in grower diets
on performance and feed digestibility of broilers, British Poultry Science, 45:2, 273-279, DOI:
10.1080/00071660410001715885
To link to this article: https://doi.org/10.1080/00071660410001715885
Published online: 19 Oct 2010.
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Effects of inclusion of poultry by-product meal and enzyme-prebiotic
supplementation in grower diets on performance and feed
digestibility of broilers
F. KIRKPINAR, Z. AC¸IKGO
¨Z, M. BOZKURT
1
AND V. AYHAN
2
Ege University, Faculty of Agriculture, Department of Feeds and Animal Nutrition,
_
IIzmir,
1
Erbeyli Research
Institute, Aydın and
2
Su¨leyman Demirel University, Faculty of Agriculture, Department of Feeds and Animal
Nutrition, Isparta, Turkey
Abstract 1. Two experiments were conducted to determine the effects of level of inclusion of poultry
by-product and enzyme-prebiotic supplementation on grower diet digestibility and the performance
of broilers.
2. Six grower diets were formulated to provide a similar nutrient profile with the exception of using
three graded levels of poultry by-product, namely 0, 25, 40 g/kg of the diet with and without
supplementation of enzyme preparation at the rate of 1 kg per tonne of feed and prebiotic preparation
at the rate of 2 kg per tonne of feed. The experimental diets were used from 3 to 6 weeks of age.
3. Body weights, feed intake and feed conversion efficiency were not affected by poultry by-product;
however, enzyme-prebiotic had a significant positive effect on feed conversion efficiency at 0 to 6 weeks
in experiment 1.
4. Crude protein digestibility was decreased by feeding the diet containing poultry by-product while
ether extract digestibility was increased by poultry by-product at the rate of 25 g per kg of feed only. Dry
matter retention, crude fibre digestibility and organic matter retention were not affected by poultry
by-product. Dry matter and organic matter retentions, crude protein, ether extract and crude fibre
digestibilities were not affected by enzyme-prebiotic.
5. Protein efficiency ratio (PER) values were increased by poultry by-product at the rate of 40 g per kg
of feed and addition of enzyme-prebiotic.
INTRODUCTION
Poultry waste management and disposal are
serious problems for the poultry industry in
Turkey. These by-products could be an envi-
ronmental liability if improperly disposed of
(Patterson, 1995). Fresh poultry waste can be
converted into quality animal feeding meal when
rendered. Poultry by-products, such as poultry
by-product meal (Escalona et al., 1986; Escalona
and Pesti, 1987; Mendonca and Jensen, 1989),
feather meal (Han and Parsons, 1991), hatchery
waste (Miller, 1984), inedible eggshell (Froning
and Bergquist, 1990) and spent hen meal (Kersey
and Waldroup, 1998; Douglas and Parsons, 1999)
are used in poultry diets. Poultry by-product
meals were acceptable and highly utilisable as a
protein and nutrient substitute in the diets of
commercial broiler chickens. Although poultry
by-product meal from broilers has the potential
of being included in broiler feeds, its feeding
value has not been studied to the extent that
would seem to be warranted. Escalona and Pesti
(1987) found that chick growth and feed effi-
ciency were significantly depressed when poultry
by-product meal was incorporated into the diet at
100 g/kg. The composition of poultry by-product
meals will vary depending upon source of raw
materials and method of processing ( Johnson
and Parsons, 1997). No research has been
published on the nutrient digestibility of poul-
try by-product meal except for amino acid
digestibility.
The present study was conducted to deter-
mine the effects of dietary inclusion levels of
poultry by-product and enzyme-prebiotic supple-
mentation on broiler diet digestibility and broiler
performance. Two experiments were conducted.
The first was conducted in order to determine
growth performance. The second was conducted
in order to determine dry matter and organic
matter retention and ether extract, crude fibre,
Correspondence to: F. Kırkpınar, Ege University, Faculty of Agriculture, Department of Feeds and Animal Nutrition,
_
IIzmir, Turkey. Fax: þ90-232-
3881867. E-mail: fkirkpinar@hotmail.com
Accepted for publication 28th November 2003.
British Poultry Science Volume 45, Number 2 (April 2004), pp. 273–279
ISSN 0007–1668(print)/ISSN 1466–1799(online) 2004 British Poultry Science Ltd
DOI: 10.1080/00071660410001715885

crude protein digestibility and protein efficiency
ratio (PER).
MATERIALS AND METHODS
Diets
Poultry by-product meal was obtained from
Keskinog˘lu Co. (Kayal|og˘lu Kasabas|, Akhisar,
Manisa, Turkey). The product was derived from
poultry including feathers, heads, feet and
inedible entrails (intestine, lung, spleen). The
product was boiled at 100C with a pressure of
2.2 kg/cm
2
for 15 min. Then, the product was
boiled at 100C for 5 h, followed at 130C for 1 h.
The resulting poultry by-product was cooled at
ambient temperature and some of its oil was
removed. The material was then ground in a
hammer mill. Ethoxyquin (1 g/kg) was incorpo-
rated into the product as an antioxidant. All the
material was blended and sampled for nutrient
analysis. Dry matter content was determined
by oven-drying at 105C for 16 h. Crude protein
was determined by the Kjeldahl method. Ether
extract content was obtained by Soxhlet extrac-
tion using anhydrous diethyl ether. The samples
were analysed for ash, calcium and phosphorus
according to the procedures of the AOAC
(1980). Amino acid composition of the poultry
by-product was determined by Eurolysine Custo-
mer’s Laboratory (ZI Longpre
´, Amiens, France).
Metabolisable energy (ME) was estimated using a
prediction equation (NRC, 1994):
ME, MJ=kg ¼001298 crude protein g=kg
þ003300 ether extract g=kg:
The nutrient make-up of the poultry by-product
meal is detailed in Table 1. All chicks were given
starter diets from 0 to 3 weeks of age and experi-
mental grower diets from 3 to 6 weeks of age in
both experiments 1 and 2. Six grower diets were
formulated to provide a similar nutrient profile
with the exception of using three graded levels of
poultry by-product, namely 0, 25, 40 g/kg of
the diet, with and without supplementation of
enzyme preparation at the rate of 1 kg per tonne
of feed and prebiotic preparation (Table 2) at the
rate of 2 kg per tonne of feed. The dietary
treatments consisted of 0, 25, 40 g/kg poultry
by-product meal replacing portions of other
ingredients with meat and bone meal content
kept unchanged. Maize
—
soybean based diets were
utilised and all were formulated using linear
programming to be isoenergetic, isonitrogenous
and to contain equal amounts of dry matter,
crude fibre, crude ash, calcium, total phosphorus,
sulphur amino acids and lysine. The experi-
mental diets containing poultry by-product were
adjusted to have similar lysine contents by
modification of the proportions of sunflower
meal and synthetic lysine. The experimental diets
used are given in Table 2.
Experimental feeds were ground through
a 1 mm screen in preparation for chemical analy-
sis. Dry matter content was determined by oven-
drying at 105C for 16 h. Crude protein was
determined by the Kjeldahl method (AOAC,
1980). Ether extract content was obtained by
Soxhlet extraction using anhydrous diethyl ether.
The crude fibre content was determined using
12.5% sulphuric acid and 12.5% sodium hydrox-
ide solutions (Naumann and Bassler, 1993).
The samples were analysed for starch, sugar,
ash, calcium and phosphorus according to the
procedures of the AOAC (1980). Estimates of ME
were based on protein, ether extract, starch and
sugar levels determined from the experimental
feeds. ME was estimated using a prediction
equation (Rose, 1997):
ME;MJ=kg ¼003431ðfat g=kgÞ
þ001551ðcrude protein g=kgÞ
þ001301ðtotal sugar g=kgÞ
þ001669ðstarch g=kgÞ:
Experimental design and traits measured
Experiment 1
A total of 1800 1-d-old male and female Ross-
PM3 broiler chicks were individually weighed,
and distributed into 24 floor pens with 75
chicks per pen. The number of males and
females were allocated to each of the pens
randomly. Each 3.3m1.7 m floor pen was
Table 1. Determined nutrient composition of poultry
by-product meal (PBP)
Nutrient composition g/kg
Dry matter 896.7
Crude protein 615.3
Crude fat 190.0
Crude ash 64.9
Total calcium 17.6
Total phosphorus 12.1
Crude fibre 26.5
ME (MJ/kg) 14.3
Linoleic acid 46.0
Lysine 20.2
Methionine 6.4
Methionine þcystine 21.9
Arginine 30.2
Tryptophan 3.8
274 F. KIRKPINAR ET AL.

furnished with wood shavings litter, two round
feeders and a round drinker. The diameter of
the feeder was 41 cm and that of the drinker
was 35 cm.
At the age of 21 d, birds were weighed
individually and three male birds of similar body
weight per pen were selected and moved from
floor pens to individual metabolic cages for
experiment 2. Birds were weighed individually
at 3 and 6 weeks of age. Body weight gain was
calculated from 0 to 3 and 3 to 6 weeks. Six dietary
treatments were replicated with 4 pens and fed
from 21 to 42 d of age. Feed and water were
consumed ad libitum. Temperature and relative
humidity were maintained within the optimum
range. Lighting was 23 h light:1 h darkness. Total
feed intake was measured per cage at 3 and
6 weeks of age. Mortality was recorded daily.
Feed intake and feed conversion efficiency were
adjusted for mortality.
Experiment 2
At 21 d of age, 72 male birds of similar
body weight were obtained from experiment 1.
Dietary treatments were the same as experiment 1.
Birds were placed into individual metabolic cages
and distributed into 6 groups of 12 chicks. The
metabolic cages were 31.5cm31 cm 48 cm
in width, length and height, respectively. Feed
and water were consumed ad libitum. Tempera-
ture and relative humidity were maintained within
the optimum range. Lighting was 23 h light:1 h
darkness.
Total feed intake was measured individually.
Feed digestibility was measured from d 31 to 38
Table 2. The composition of starter diet at 0 to 3 weeks and experimental grower diets at 3 to 6 weeks (g/kg) (Experiment 1 and 2)
Ingredient Starter diet (0–3 wk) Grower diets (3–6 wk)
CCþE-P 25 g/kg PBP 25 g/kg
PBP þE-P
40 g/kg PBP 40 g/kg
PBP þE-P
Wheat
—
95.07 95.07 116.00 116.00 119.26 119.26
Yellow maize 509.33 492.00 489.00 465.27 462.27 494.28 491.28
Soybean meal 252.07 237.23 237.23 212.97 212.97 208.21 208.21
Meat-and-bone meal
—
20.00 20.00 20.00 20.00 20.00 20.00
Fish meal 50.97 27.07 27.07 15.50 15.50 15.69 15.69
Sunflower meal 100.00 60.31 60.31 74.76 74.76 46.19 46.19
Poultry by-product meal
———
25.00 25.00 40.00 40.00
Dicalcium phosphate 10.04
—— — — — —
Ground limestone 19.76 10.00 10.00 10.00 10.00 6.86 6.86
Vegetable oil 48.83 47.74 47.74 49.52 49.52 38.51 38.51
Iodised sodium chloride 2.50 2.50 2.50 2.50 2.50 2.50 2.50
Vitamin mixture
1
2.50 2.50 2.50 2.50 2.50 2.50 2.50
Trace mineral mixture
2
1.00 1.00 1.00 1.00 1.00 1.00 1.00
L-Lysine 1.00 1.64 1.64 2.00 2.00 2.00 2.00
DL-Methionine 1.00 1.94 1.94 1.98 1.98 2.00 2.00
Coccidiostat
3
1.00 1.00 1.00 1.00 1.00 1.00 1.00
Enzyme-Prebiotic
4
——
3.00
—
3.00
—
3.00
Analysed composition (g /kg)
Dry matter 914.9 866.6 866.1 868.6 870.1 881.3 885.1
Crude protein 227.5 192.8 195.0 193.1 194.1 193.3 194.2
Crude fat 67.561
.761
.665
.765
.068
.868
.6
Crude fibre 40.045
.245
.147
.746
.647
.447
.0
Starch 375.0 378.3 375.0 375.0 375.9 375.6 380.3
Sugar 44.836
.833
.132
.235
.831
.832
.9
Crude ash 70.856
.556
.556
.656
.356
.356
.6
Total calcium 12.013
.313
.014
.014
.015
.215
.1
Total phosphorus 6.55
.35
.55
.35
.45
.66
.0
Calculated composition
ME (MJ/kg) 12.711
.911
.811
.912
.012
.012
.1
Lysine 12.911
.211
.210
.910
.910
.810
.8
Methionine 5.35
.55
.55
.55
.55
.45
.4
Methionine þcystine 8.98
.98
.99
.09
.09
.19
.1
Available phosphorus 4.23
.23
.23
.13
.13
.23
.2
1
Supplied mg/kg of diet: retinol acetate, 5.16; cholecalciferol, 0.0375; tocopheryl, 20; menadione, 5; thiamine, 3; riboflavin, 6; niacin, 25; calcium
D-pantothenate, 12; pyridoxine, 5; cyanocobalamin, 0.03; folic acid, 1; D-biotin 0.05; choline chloride, 400; carophyll yellow, 25.
2
Supplied mg/kg of diet: manganese, 80; iron, 60; zinc, 60; copper, 5; cobalt, 0.2; iodine, 1; selenium, 0.15; calcium carbonate, 447.
3
Supplied mg/kg of diet: 75 ppm Lasalocid sodium (Avatec, Roche).
4
The enzyme preparation (1 g/kg) is a potent source of protease (7500 U/g), as well as of cellulase (500 U/g), amylase (350 U/g) and xylanase (350 U/g),
endo-1,3; 1,4-beta glucanase (300 U/g), lipase (50 U/g) and b-glucosidase (40 U/g), phytase (10 U/kg) activities (Protosyn
2000
, Plastchim, Bulgaria).
The prebiotic preparation (2g/kg) is comprised of Aspergillus meal. Aspergillus meal is derived from an active fermentation of a primary Aspergillus sp.
It is the asporogenic mycelium contained in this totally dead product (Fermacto, PetAg Inc. USA).
E-P ¼enzyme-prebiotic; PBP¼poultry by-product.
POULTRY BY-PRODUCT MEAL AND ENZYME-PREBIOTIC 275

by total collection of excreta from each cage.
Excreta were collected from individual birds daily.
In all, 72 fresh excreta samples were collected in
plastic trays, weighed and stored in an air-tight
plastic bag in a freezer until excreta samples
were required for analysis, when they were
homogenised using a blender and analysed for
dry matter, nitrogen, ether extract and crude
fibre. Dry matter content of diets and excreta
was determined by oven-drying at 105C for 16 h.
Ether extract content of diets and excreta was
obtained by the Soxhlet extraction using anhy-
drous diethyl ether. The crude fibre content of
diets and excreta was determined using 12.5%
sulphuric acid and 12.5% sodium hydroxide
solutions (Naumann and Bassler, 1993). The
Kjeldahl method was used for the analysis of
total nitrogen content of diets and excreta and
crude protein was expressed as nitrogen 6.25
(AOAC, 1980). In order to estimate protein
digestibility, faecal and urinary nitrogen were
chemically separated according to the method of
Marquardt (1983). Digestibility was determined
by accurately measuring feed intake and excreta
output. From these measurements, together with
chemical analysis for nutrients, the digestibi-
lity was calculated. PER was calculated as body
weight gain divided by crude protein intake
( Johnson and Parsons, 1997).
Statistical analysis
Data were subjected to ANOVA using General
Linear Models (SAS, 1986). The model included
level of dietary poultry by-product content and
enzyme-prebiotic supplementation and inter-
actions between poultry by-product level and
enzyme-prebiotic supplementation. Pen means
served as the experimental unit for statistical
analysis. Data on feed intake and feed conversion
efficiency were analysed using the same model
across the sexes in experiment 1.
RESULTS
Performance (experiment 1)
Average liveability value was 98.70.49 (%) for
experiment 1 and there were no treatment
differences. Body weights of broilers at 6 weeks
were not affected by poultry by-product; how-
ever, body weight means were affected by
enzyme-prebiotic treatment (Table 3). Enzyme-
prebiotic supplementation significantly increased
body weights at 6 weeks. Total feed intakes of
broilers were not affected by poultry by-product
and enzyme-prebiotic supplementation. How-
ever, feed intakes were increased by feeding the
diet containing poultry by-product at the rate of
25 g per kg of feed as compared with the control
at 3 to 6 weeks. The poultry by-product 
enzyme-prebiotic interaction was significant for
the feed intake at 3 to 6 weeks and 0 to 6 weeks
(Figure 1). No effects (P>0
.05) of poultry by-
product were found for feed conversion effi-
ciency. Enzyme-prebiotic supplementation had a
significant positive effect on feed conversion
efficiency at 3 to 6 weeks and 0 to 6 weeks.
These results indicate that the addition of
enzyme-prebiotic improved the feed conversion
efficiency (P<0
.05).
Digestibility and protein efficiency ratio(PER)
(experiment 2)
Dry matter and organic matter retention, ether
extract, crude fibre and crude protein digesti-
bilities, PER, feed intake and feed conversion
Table 3. Effects of dietary poultry by-product (PBP), enzyme-prebiotic (E-P) on the body weight, feed intake and feed conversion
efficiency, Experiment 1
Body weights (g) Feed intake (g) Feed conversion efficiency
(weight gain/feed intake)
3 wk 6 wk 0–3 wk 3–6 wk 0–6 wk 0–3 wk 3–6 wk 0–6 wk
PBP (g/kg)
0 766.72 1924 1207 2410
b
3618 0.60 0.48 0.52
25 765.04 1914 1200 2473
a
3673 0.60 0.46 0.51
40 771.17 1920 1213 2454
ab
3667 0.61 0.47 0.51
SEM 3.96 7.48 6.77 16.12 16.07 0.003 0.004 0.003
E-P
767.07 1902
b
1202 2452 3654 0.61 0.46
a
0.51
a
þ768.22 1936
a
1211 2439 3651 0.60 0.48
b
0.52
b
SEM 3.23 6.11 5.54 13.16 13.12 0.002 0.004 0.003
Source of variation Probabilities (P-values)
PBP 0.545 0.663 0.399 0.045 0.064 0.650 0.057 0.091
E-P 0.806 0.002 0.258 0.489 0.874 0.064 0.007 0.023
PBP E-P 0.997 0.186 0.755 0.008 0.009 0.881 0.268 0.299
a,b
Means within a column in each variable with no common superscript differ significantly (P0.05).
SEM ¼standard error of means (pooled).
276 F. KIRKPINAR ET AL.

efficiency for the period from 31 to 38 d are
presented in Table 4. Dry matter, organic matter
retention and crude fibre digestibilities were not
affected by poultry by-product or enzyme-
prebiotic supplementation. The poultry by-product
enzyme-prebiotic interaction was significant
(P<0
.05) for dry matter retention (Figure 2). This
interaction resulted because the birds fed on the
poultry by-product diets had the same (P>0
.05)
dry matter retention, while the birds fed on
the enzyme-prebiotic supplemented diet (25 g/kg
poultry by-product), had a higher dry matter
retention than birds fed on the 40 g/kg poultry
by-product supplemented diet and control
diet. Crude protein digestibility was signifi-
cantly reduced in birds fed on the 40 g/kg
poultry by-product supplemented diet compared
with that of birds fed on the 25 g/kg poultry
Table 4. Dry matter (DM) and organic matter (OM) retentions, crude protein (CP), ether extract (EE), crude fiber (CF) digestibility
coefficients, protein efficiency ratio (PER), feed intake (FI) and feed conversion efficiency (weight gain/feed intake) (FCE) of broilers at
31–38 days, Experiment 2
DM OM EE CF CP PER FI FCE
PBP (g/kg)
00
.722 0.957 0.799
b
0.337 0.703
a
2.44
b
1076.81
a
0.47
a
25 0.735 0.931 0.871
a
0.365 0.663
a
2.46
b
1007.49
b
0.48
a
40 0.723 0.956 0.810
b
0.271 0.571
b
2.74
a
924.40
c
0.53
b
SEM 0.006 0.024 0.016 0.028 0.016 0.059 24.28 0.011
E-P
0.728 0.957 0.822 0.320 0.631 2.46
b
990.02 0.48
a
þ0.726 0.939 0.831 0.328 0.660 2.63
a
1019.78 0.51
b
SEM 0.005 0.019 0.013 0.023 0.014 0.049 20.06 0.009
Source of variation
PBP 0.147 0.621 0.007 0.073 0.000 0.004 0.001 0.001
E-P 0.721 0.502 0.615 0.821 0.143 0.016 0.369 0.017
PBP E-P 0.023 0.635 0.483 0.294 0.133 0.161 0.606 0.059
a,b,c
Means within a column in each variable with no common superscript differ significantly (P0.05).
SEM ¼standard error of means (pooled).
aaaa
2000
2250
2500
2750
3000
3250
3500
3750
4000
Feed intake (g)
With enzyme -
prebiotic
Without enzyme -
prebiotic
With enzyme -
prebiotic
Without enzyme -
prebiotic
0 g/kg PBP 25 g/kg PBP 40 g/kg PBP
0-6 wk
3-6 wk
b b
aa a a a a
Figure 1. Poultry by-product enzyme-prebiotic interactions on feed intake at 3
—
6 weeks and 0
—
6 weeks, Experiment 1. Each value
shows mean SEM of the feed intake. Bars with different letters are significantly different (P < 0.05).
ab
0⋅70
0⋅71
0⋅72
0⋅73
0⋅74
0⋅75
0⋅76
0 g/kg PBP 25 g/kg PBP 40 g/kg PBP
Levels of PBP (g/kg)
Dry matter retention (g/kg)
With enzyme - prebiotic Without enzyme - prebiotic
b
b b ab
Figure 2. Poultry by-product enzyme-prebiotic interactions on dry matter retention values at 31–38 d, Experiment 2. Each value
shows mean SEM of dry matter retention. Bars with different letters are significantly different (P < 0.05).
POULTRY BY-PRODUCT MEAL AND ENZYME-PREBIOTIC 277

by-product supplemented diet and control.
Ether extract digestibility was significantly
increased in birds fed on the 25 g/kg poultry
by-product supplemented diet compared with
that of birds given 40 g/kg poultry by-product
and control. Enzyme-prebiotic supplementation
did not affect crude protein and ether extract
digestibility. PER values of broilers at 31 and 38 d
were affected by poultry by-product and enzyme-
prebiotic treatment. PER values were significantly
increased by poultry by-product at 40 g per kg of
feed and enzyme-prebiotic supplementation.
DISCUSSION
In the present experiment, ME, crude protein,
ether extract, crude fibre, calcium, linoleic acid,
methionine þcystine in the poultry by-product
meal were higher and tryptophan in the poultry
by-product meal was slightly higher than NRC
(1994) values. The dry matter, lysine, methionine,
phosphorus in the poultry by-product meal were
lower and arginine in the poultry by-product meal
slightly lower than NRC (1994) values (Table 1).
Results of experiment 1 indicate that the
birds given poultry by-product meal from 3 to 6
weeks and the maize
—
soybean meal control diets
showed no differences (P>0
.05) in body weight
at 42 d of age, total feed intake and feed con-
version efficiency. The results agree with the
findings of Escalona and Pesti (1987), who found
no difference in the performance of broilers
when poultry by-product meal was incorpora-
ted at the 5% level into maize
—
soybean practical
diets when all essential nutrients were equalised.
Bhargava and O’Neil (1975) observed equal or sig-
nificantly superior results in a series of experi-
ments with chicks fed on a poultry by-product
and hydrolysed feather meal combination when
compared with feeding an animal protein-free
wheat
—
soybean control diet. Mendonca and
Jensen (1989) found that including poultry
by-product meal in broiler diets at 100 g/kg did
not significantly affect body weight gain, feed
intake or feed conversion in comparison to a
maize
—
soybean diet. Haque et al. (1991) reported
that broiler chicks fed on a diet with 93 g/kg
extruded poultry by-product meal had similar
body weights and feed utilisation to those given
an extruded, maize
—
soybean meal control diet.
Wessels (1972) investigated the protein
quality of poultry offal meal used in chick rations
with or without amino acid supplementation.
He observed an improvement in the nitrogen
retention of chickens when methionine and
lysine were added to the experimental diet
containing poultry offal meal. Thus, methionine
and lysine were reported to be the first and
second limiting amino acids in the protein
source. Daghir (1975) found that the addition
of methionine and lysine improved growth and
feed utilisation of chicks fed the poultry feather
or offal meal diet. However, body weight was not
improved to the same extent as that of fish meal.
In experiment 1, body weight at 42 d of
age for chicks given the enzyme-prebiotic supple-
mented poultry by-product meal was higher than
that of chicks fed on a maize
—
soybean meal
control diet. The results of experiment 1 indicate
that diets containing poultry by-product meal
were not different (P>0
.05) as measured by total
feed intake. Feed conversion efficiency for the
chicks fed the enzyme-prebiotic supplemented
poultry by-product meal was higher than the
maize
—
soybean meal control diet. Barbour et al.
(1995) reported that feed intake was significantly
increased in poults given enzyme-treated whole
turkey by-product meal compared with soybean
meal. Contrary to this report, feed intake (3 to 6
weeks) for chicks fed on the enzyme-prebiotic
supplemented diets were not different from
those of chicks fed on the unsupplemented diets
in the present study. Feed conversion efficiency
(3 to 6 weeks) of birds fed the enzyme-prebiotic
supplemented diets was better than those fed
the non-enzyme-prebiotic treated diets. These
results are in agreement with the findings of
Tadtiyanant et al. (1993), who found that enzyme
treatment of feathers improved growth rate
and enzyme-treated feather extruded products
were good feed ingredients for broilers giving
feed efficiency and growth responses compara-
ble to the maize
—
soybean meal control diet.
Tadtiyanant et al. (1993) reported that the enzyme
treatment was effective in releasing feather
nutrients for utilisation by broilers.
The results of experiment 2 indicate that dry
matter and organic matter retention, and crude
fibre digestibility were not affected by poultry
by-product meal. Crude protein digestibility was
decreased in birds fed on the 40 g/kg poultry
by-product supplemented diet compared with
control and birds fed on the 25 g/kg poultry
by-product supplemented diet. Ether extract
digestibility was significantly increased in birds
fed on the 25 g/kg poultry by-product meal
supplemented diet compared with that of birds
given 40 g/kg poultry by-product and control.
The enzyme-prebiotic addition had no positive
effect on digestibility (P>0
.05). However, enzyme-
prebiotic treatment tended slightly to improve
nutrient digestibility (P>0
.05).
PER values of broilers at 31 and 38 d were
affected by poultry by-product and enzyme-
prebiotic supplementation. PER values were sig-
nificantly increased in birds fed on the 40 g/kg
poultry by-product meal supplemented diet com-
pared with control and birds fed on the 25 g/kg
poultry by-product meal supplemented diet.
278 F. KIRKPINAR ET AL.

However, the 40 g/kg level of poultry by-product
meal slightly reduced body weight. Enzyme-
prebiotic treatment did result in increased PER.
Therefore, addition of amino acids (lysine and
methionine) to the poultry by-product meals may
have influenced the results. In the present study,
the increased PER value obtained with the 40 g/kg
level of poultry by-product meal may largely have
been due to differences in digestible amino
acid levels among the diets. This is probably a
function of the increased methionine and lysine
supplementation. As more information is gen-
erated regarding typical amino acid content and
digestibility of poultry by-product meal, the
product may be used with greater confidence in
commercial diets. Escalona et al. (1986) concluded
that the PER was the most discriminating method
of estimating protein quality, especially at lower
levels. PER value was determined as 2.88 for
poultry by-product meal diet and 3.83 for the
soybean meal plus methionine diet at 200 g/kg
protein. It has been previously reported that, in
chick bioassays, no significant differences were
found in PER between the control feather meal
and enzyme-treated feather meal (Kim and
Patterson, 2000). Barbour et al. (1995) reported
that body weight and PER were significantly
increased in poults fed enzyme-treated whole
turkey by-product meal compared with soybean
meal. Kim and Patterson (2000) reported that
enzyme treatment could improve the nutritional
quality of feathers from dead hens.
It is clear from these results that poultry
by-product meal has substantial nutritional value
for poultry. However, the nutritional quality may
vary greatly among samples. Further, the amino
acid digestibility of poultry by-product meal,
particularly cystine, may need to be considered
when using high dietary levels of this ingredient
in broiler feeds.
REFERENCES
AOAC (1980) Official Methods of Analysis, 13th edn
(Washington, DC, Association of Official Analytical
Chemist).
BARBOUR, G.W., NEMASETONI,R.&LILBURN, M.S. (1995)
The effect of enzyme predigestion on the quality of
poultry by-product meal from whole turkey mortality.
Poultry Science,74: 1180
—
1190.
BHARGAVA, K.K. & O’NEIL, J.B. (1975) Composition
and utilization of poultry by-product and hydrolyzed
feather meal in broiler diets. Poultry Science,54: 1511
—
1518.
DAGHIR, N.J. (1975) Studies on poultry by-product meals
in broiler and layer rations. Poultry Science,31: 200
—
211.
DOUGLAS, M.W. & PARSONS, C.M. (1999) Dietary formula-
tion with rendered spent hen meal on a total amino acid
versus a digestible amino acid basis. Poultry Science,76:
1387
—
1391.
ESCALONA, P.R.R. & PESTI, G.M. (1987) Nutritive value
of poultry by-product meal. 3. Incorporation into
practical diets [Research Note]. Poultry Science,66:
1067
—
1070.
ESCALONA, P.R.R., PESTI, G.M. & VAUGHTERS, P.D. (1986)
Nutritive value of poultry by-product meal. 2. Compar-
isons of methods of determining protein quality. Poultry
Science,65: 2268
—
2280.
FRONING, G.W. & BERGQUIST, D. (1990) Utilization of
inedible eggshells and technical egg white using extrusion
technology. Poultry Science,69: 2051
—
2053.
HAN,Y.&PARSONS, C.M. (1991) Protein and
amino acid quality of feather meals. Poultry Science,
70: 812
—
822.
HAQUE, A.K.M.A., LYONS, J.J. & VANDEPOPULIERE, J.M.
(1991) Extrusion processing of broiler starter diets
containing ground whole hens, poultry by-product meal,
feather meal, or ground feathers. Poultry Science,70:
234
—
240.
JOHNSON, M.L. & PARSONS, C.M. (1997) Effect of
raw material source, ash content, and assay length
on protein efficiency ratio and net protein ratio
values for animal protein meals. Poultry Science,
76: 1722
—
1727.
KERSEY, J.H. & WALDROUP, P.W. (1998) Utilization of spent
hen meal in diets for broiler chickens. Poultry Science,77:
1377
—
1387.
KIM, W.K. & PATTERSON, P.H. (2000) Nutritional value of
enzyme or sodium hydroxide-treated feathers from dead
hens. Poultry Science,79: 528
—
534.
MARQUARDT, R.R. (1983) A simple spectrofotometric
method for the direct determination of u
¨ric acid in avian
excreta. Poultry Science,62: 2106
—
2108.
MENDONCA, C.X., JR&JENSEN, L.S. (1989) Effect of
formulating diets with different assigned energy data for
poultry by-product meal on the performance and abdom-
inal fat content of finishing broilers. Poultry Science,68:
1672
—
1677.
MILLER, B.F. (1984) Extruding hatchery waste. Poultry Science,
63: 1284
—
1286.
NATIONAL RESEARCH COUNCIL (1994) Nutrient Requirements
of Poultry, 9th rev. edn (Washington, DC, National
Academy Press).
NAUMANN,C.&BASSLER, R. (1993) Methodenbuch, Band III.
Die Chemische Untersuchung von Futtermitteln (Darmstadt,
Germany, VDLUFA-Verlag).
PATTERSON, P.H. (1995) Recycled poultry by-products.
Feed Mix,3(6): 26
—
28.
ROSE, S.P. (1997) Principles of Poultry Science (Wallingford,
CAB International).
SAS (1986) User’s Guide, Version 5 (Cary, NC, SAS Institute,
Inc.).
TADTIYANANT, C., LYONS, J.J. & VANDEPOPULIERE, J.M.
(1993) Extrusion processing used to convert dead poultry,
feathers, eggshell, hatchery waste, and mechanically
deboned residue into feedstuffs for poultry. Poultry
Science,72: 1515
—
1527.
WESSELS, J.P.H. (1972) A study of the protein quality of
different feather meals. Poultry Science,51: 537
—
541.
POULTRY BY-PRODUCT MEAL AND ENZYME-PREBIOTIC 279