Production of low fat and low cholesterol broiler meat by supplementing
organic minerals or polyunsaturated oil
Suchon Tangtaweewipat1, Boonlom Cheva-Isarakul1 and Thanadeach Mahuemaung1
1
Department of Animal Science, Faculty of Agriculture, Chiang Mai University, 50200,
Thailand
Summary
The study on the reduction of fat and cholesterol in broiler meat was done in 1,050 heads of
Arbor Acre broilers, mixed sex during 8-49 days of age. The chicks were randomly
allotted to 7 groups, each with 3 replicates. The control diet had 3% palm oil (PO) as one
of the energy source. The first 4 experimental diets were supplemented with organic
minerals (either 125 and 250 ppm Cu1/ or 200 and 400 ppb Cr2/) while the other 2 diets,
polyunsaturated oil (PUFO) from either soybean or linseed was used to substitute PO of
the control diet. All test diets tended to give better performances than the control. The
soybean oil (SBO) group significantly showed better weight gain while the linseed oil
(LSO) group had significantly better FCR. Abdominal fat tended to be lower by the
supplement of Cu or Cr. This effect was significant in the PUFO groups. Cholesterol in
serum, breast and drumstick meat significantly decreased (13.2-27.4, 10.7-30.5 and 8.227.1%, respectively) when supplemented with organic minerals, or when PUFO
substituted PO. The highest reduction of cholesterol in breast and drumstick meat was
found when Cu was added. The cost of production decreased 0.34 and 0.50 Bt/kg BW (40
Bt = 1 $US) in SBO and LSO group, respectively while the mineral groups had slightly
higher cost, i.e. 0.37 and 0.91 Bt/kg BW in the group fed with low level of Cu and Cr,
respectively.
Keywords: Broiler, Cholesterol, Chromium, Copper, Plant oil, Carcass quality.
Introduction
Atherosclerosis and cholesterolemia are two of the major causes of human death. These
diseases are assumed to be influenced by diets of high saturated fatty acids and
cholesterol. Therefore attempts have been made to produce low cholesterol meat and
eggs. Many methods including the supplement of copper (Cu), chromium (Cr) and
polyunsaturated oils (PUFO) were reported. Copper is the well-known growth promotant
in swine. It also involved in metabolism of lipid and cholesterol by reducing the activity
of fatty acid synthetase and cholesterol 7 - hydroxylase (Konjufca et al., 1997). Cu
deficiency was reported to cause hypercholesterolemia in rats. Pesti and Bakalli (1996)
and Konjufca et al. (1997) reported that the supplement of CU sulfate or citrate reduced
cholesterol in blood and meat while improved the performance of broilers.
Chromium is the component of glucose tolerance factor (GTF) which activates
insulin in enhancing glucose uptake of cells and regulate lipid and cholesterol
metabolism. The supplement of 300 ppb Cr in the form of Cr yeast improved FCR,
mortality rate, carcass and breast weight while decreased abdominal fat (Hossain et al.,
1998)
Materials and Methods
A total of 1,050 day-old straight run Arbor Acre broiler chicks was allotted into 7 groups
with 3 replicates of 50 birds each. The birds in each replicate were kept together in a 1.3 x
5.0 m floor pen. During the first week, all birds were fed a pelletized commercial broiler
starter diet containing 21% CP. Then they were fed with diets containing 21, 19 and 17%
CP during week 2-3, 4-6 and 7 of chicks’ age, respectively. The ME value was fixed at
3.15 kcal/g throughout the experiment. The control diet had 3% PO as one of the energy
source. The first 4 experimental diets were supplemented with organic minerals (either
125 and 250 ppm Cu or 200 and 400 ppb Cr). The other 2 diets, PUFO from either
1/
2/
Bioplex copper ®; copper was in the form of proteinates.
Bio-chrom®; chromium was trivalent (Cr3+) and being in the form of chromium yeasts.
soybean or linseed was used to substitute PO of the control diet without the supplement of
Cu or Cr.
The experiment was conducted at Chiang Mai University Farm. At the end of the
experiment, 2 birds of each sex from each replicate was slaughtered for evaluation of
carcass quality. Cholesterol content in serum and in muscle (breast and drumstick) was
determined by calorimetric and enzymatic methods, respectively. In addition, Cu content
in visceral organs (heart, liver and gizzard) as well as in gastrointestinal tract was
measured by Atomic absorption spectrophotometry.
Results and Discussion
Production performance and carcass quality
There was no significant difference among groups on body weight gain, feed intake and
FCR (Table 1). However, the significantly higher weight gain (2.22 vs. 2.07 kg) and
better FCR (2.21 vs. 2.39) as compared to the control, were found in the groups fed with
SBO and LSO, respectively. It might be due to the better feed utilization when diet
containing higher polyunsaturated fatty acid (PUFA) (Zollitsch et al., 1997).
The supplement of low Cu (125 mg/kg) tended to give better performance than the
control and the supplement of 250 mg Cu/kg. The result was in agreement with Pesti and
Bakalli (1996) who found no further advantage when the supplement level of organic copper
citrate was higher than 125 mg/kg. It indicated that organic Cu was more efficiency than
inorganic Cu. And since Cu in this study was an organic form which had better absorption
ability, therefore the toxicity due to higher supplement level should be avoided. No
significant difference was observed on the supplement of Cr at 200 and 400 ppb.
Table 1. Production performance, cholesterol content and production cost of broilers fed
diets containing plant oils or Cu or Cr during 2-7 weeks of age.
Source of plant oil
Control
Production performance
Body weight gain 1 (kg)
2.07 b
Feed intake (kg)
4.95 a
FCR
2.39 a
Mortality (%)
3.36 abc
Carcass quality
Dressing (%)
76.2 a
Visceral organ (% BW)
Gizzard
1.31 a
Liver
2.11 a
Abdominal fat
1.80 ab
GI tract
8.77 ab
Breast (% BW)
13.8 a
Drumstick (% BW)
9.8 a
Cholesterol
In serum (mg/dl)
130.5 a
In muscle (mg/100 g)
Breast
57.7 a
Drumstick
82.6 a
2
Production cost (40 Bt = 1 $US)
(Bt/kg BW gain)
19.09
Palm oil
Cu (ppm)
Cr (ppb)
125
250
200
400
2.17 ab
5.05 ab
2.33 ab
4.71 ab
2.05 b
4.85 bc
2.36 ab
2.03 bc
2.13 ab
5.02 abc
2.36 ab
6.13 a
2.14 ab
5.10 a
2.38 a
0.67 c
76.5 a
Soybean
Oil
Linseed
Oil
2.22 a
5.06 ab
2.28 ab
0.68 c
2.17 ab
4.80 c
2.21 b
2.67 bc
77.3 a
75.2 a
76.2 a
1.28 a
2.23 a
1.56 ab
8.65 b
14.8 a
10.0 a
1.35 a
2.14 a
1.62 ab
9.63 a
14.1 a
9.6 a
1.32 a
1.29 a
1.24 a
a
a
2.20
2.14
2.03 a
abc
bc
1.58
1.34
1.22 c
a
ab
9.52
9.33
8.37 b
a
a
14.0
14.5
14.6 a
a
a
9.9
9.9
10.1 a
113.3 b
107.1 c
103.4 d
42.4 ef
62.6 ef
40.1 f
60.2 f
44.8 de
66.3 de
19.46
20.65
20.00
97.7 e
77.9 a
77.6 a
1.32 a
2.02 a
1.17 c
8.84 ab
14.5 a
9.8 a
94.7 e
109.8 c
50.0 b
75.8 b
51.5 b
71.9 bc
49.1 bc
69.1 cd
21.40
18.75
18.59
Values within a row with no common superscripts are significantly different (P<0.05)
GI = gastrointestinal tract.
1
In the first week, BW gain and feed intake were 80 and 140 g./bird, respectively.
2
Ingredient price (Bt/kg): corn 5.30, defatted rice bran 4.00, soybean meal 10.20, fish meal 20.00, palm oil
18.00, soybean oil 22.00, linseed oil 25.00, dicalcium phosphate 13.00, oyster shell 2.00, DL-Met 120.00,
Lysine 75.00, salt 2.00, vitamin mineral premix 65.00, Bioplex-copper (10%) 300.00 and Bio-chrom
1,250.00. (40 Bt = 1 $ US)
2
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Mortality rate of chicks in this experiment (0.7-6.1%) was in normal practical
range. The highest death rate found in the group fed 200 ppb Cr was due to the fact that
the pen of one replication in this group exposed to direct sunlight which thus caused heat
stock. The lowest death rate of the group fed 400 ppb Cr might be due to the immune
enhancement effect of this mineral by decreasing corticosterone secretion. The result was
similar to Sahin et al. (2003) in broilers.
Abdominal fat tended to reduce when supplemented with both levels of Cu and
Cr. It might be due to the fact that trivalent Cr is the component of GTF which
potentiates the action of insulin in stimulating glucose uptake of the cell and reduces fat
synthesis from glucose, therefore decreases lipid accumulation. The significant reduction
of abdominal fat, as compared to the control was found in the supplement of SBO and
LSO. It might be due to the ability of PUFA to reduce fatty acid synthetase activity. The
result coincided with Santz et al. (2000). The other carcass quality e.g. dressing
percentage, visceral organs including gizzard and liver as well as debone drumstick and
breast meat were not affected by treatments.
Cholesterol in serum and muscle
The concentration of cholesterol in serum and meat (drumstick and breast) of all
treatments were significantly lower than the control. The reduction was 13.2-27.4, 10.730.5 and 8.2-27.1%, respectively (Table 1). The result was similar to Pesti and Bakalli
(1996) who supplemented Cu in the form of sulfate and citrate to broiler diet. The effect
might be owing to the fact that Cu decreases GSH thus reduces the activity of HMG CoA
reductase in regulating the synthesis of cholesterol (Konjufca et al.,1997).
The effect of Cr coincides with Sahin et al. (2003) who found that the supplement
at 400 ppb in broiler diet significantly decreased serum cholesterol and glucose levels but
increased serum insulin. The role of SBO and LSO on cholesterol reduction should be
owing to their high PUFA content as in the case of abdominal fat.
Production cost
The cost of production per kg weight gain (considered only feed cost) of SBO and LSO
groups was cheaper than the control due to their better FCR. On the other hand, the
supplement of Cu or Cr slightly increased the production cost due to the high price of
Bioplex® and Bio-chrom® (7.5 vs. 31.25 $US/kg, respectively). The use of inorganic
minerals might reduce the cost but the efficiency may be lower.
Reference
Hossain Sazzad M., L. sergio Barreto and G. Silva Carlos, 1998. Growth performance and carcass
composition of broilers fed supplemental chromium from chromium yeast. Animal Feed Sci.
T
e
c
h n o l
.
7
1 :
2 1
7
- 2
2 8 .
Konjufca, V.H., G.M. Pesti and R.I. Bakalli, 1997. Modulation of cholesterol levels in broiler
meat by dietary garlic and copper. Poultry Sci. 76: 1,264 -1,271.
Pesti, G.M., and R.I.Bakalli, 1996. Studies on the feeding of cupric sulfate pentahydrate and
cupric citrate to broiler chickens. Poultry Sci. 75: 1,086 -1,091.
Sahin, K., N. Sahin and O. Kucuk, 2003. Effects of chromium, and ascorbic acid supplementation
on growth, carcass traits, serum metabolites, and antioxidant status of broiler chickens reared at a
high ambient temperature (32C). Nutrition Research 23: 225 -238.
Santz, M., J. Lopez-Bote, D. Menoyo and J.M. Bautista, 2000. Abdominal fat deposition and fatty
acid synthesis are lower and -oxidation is higher in broiler chickens fed diets containing
unsaturated rather than saturated fat. J. Nutr. 130: 3,034 -3,037.
Zollitsch, W., F. Aichinger and F. Lettner, 1997. Effects of different dietary fat sources on
performance and carcass characteristics of broilers. Animal Feed Sci. Technol. 66: 63-73.
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