Journal of Animal Science and Veterinary Medicine
Volume 1. Page 1-9. Published 16th May, 2016 
www.integrityresjournals.org/jasvm/index.html
Research Journals Full Length Research
Effects of stocking density, energy and protein 
content on performance of broiler chickens raised
during late wet season
Ademulegun, T. I.1* and Adeyemo, G. 0 .2
1 Nutrition and Dietetics Department, Rufus Giwa Polytechnic,Owo, Ondo State, Nigeria, 
departm ent of Animal Science, University of Ibadan, Ibadan, Nigeria.
“Corresponding author. Email: tadext4@gmail.com.
Copyright © 2016 Ademulegun and Adeyemo. This article remains permanently open access under the terms of the Creative Commons Attribution 
License 4,0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received 29th February, 2015; Accepted 28th April, 2016
ABSTRACT: A 56-day feeding trial to investigate the effects of stocking density, energy and protein content on 
performance of broiler chickens during late wet season was carried out. In a 3 x 2 x 3 factorial arrangement using 
completely randomized design, six diets with three energy and two crude protein levels were formulated. Three 
stocking densities (birds/m2) of 10, 12 and 14 were used. A total of 576 one-week old Arbor Acre broilers chickens 
were assigned to the respective diets and stocking density, at 32 birds per treatment. Weight gain, feed intake, feed 
conversion ratio, survival rate, carcass yield, live weight/ m2 and feed cost / live weight were assessed. Data were 
analyzed, using descriptive statistics and ANOVAao.os. Energy x crude protein x stocking density interaction affects 
the feed intake (p<0.05) and the highest value was obtained using diet with low energy and crude protein levels. 
Treatment did not affect (p>0.05) survival rate, however, stocking density at 12 birds/m2 resulted in the best values 
(p<0.05) of weight gain (2230.71g) and feed conversion ratio (2.10) and the use of diets with lower crude protein and 
energy increased (p<0.05) the weight gain (2312.42g). The carcass yield was affected (p<0.05) by the interaction of 
energy x crude protein x stocking density, (p<0.05) with the lowest value (67.33%) found with birds raised on 
stocking density, 10 birds/m2 and diets with low crude protein and recommended energy. The lowest feed cost/live 
weight (p<0.05) was observed with stocking density at 12 birds/m2. Broiler chickens may be economically raised at 
stocking density 12 birds/m2 and on diet containing 2933kcal/kg ME with 21.92% crude protein for starter phase and 
3095 kcal/kgME and 19.14% crude protein for finishers during late wet season in Nigeria.
Key Words: weight gain, carcass yield, feed cost, feed conversion ratio.
INTRODUCTION
Broilers, like any other living organism, must be higher SD, the profit per chicken decreases, total 
provided with optimal environmental conditions and production of meat per unit of floor surface increases, 
feed in order to achieve their genetic potential for and this results in higher profit (Ravindran et al., 2006). 
growth (Feddes et al., 2002). The significance of Stocking density as high as 20 birds/m2 or 30-35kg/m2 
stocking density (SD) in broiler production has long had been suggested and used in environmentally 
been established (Skrbic et al., 2009). However, the controlled house (Thomas et al., 2004; Skrbic et al., 
intensive selection work and creation of more 2009), while SD varying from 6-14 bird/m2 had been 
productive genotypes has made the modern used in open-sided houses (Yadgari et al., 2006, 
commercial lines of broiler chickens more demanding in Yakubu et al., 2010). Several studies have been 
terms of housing conditions, nutrition and handling conducted to study the effect of SD on broilers 
(Skrbic et al., 2009). The ultimate goal of poultry production and performance. However, majority of 
producers is to maximize kilogram of chicken produced these studies were inconclusive since some showed 
per sguare meter of space while preventing production large benefits in reducing SD on the performance of 
losses due to overcrowding to achieve a satisfactory broilers (Dozier et al., 2005, 2006; Skrbic et al., 2009), 
economic return (Abudabos et al., 2013). Although in while others documented that reducing SD has no
UNIVERSITY OF IBADAN LIBRARY
J. Anim. Sci. Vet. Med. 2
influence (Thomas et al., 2004) or even negative University of Ibadan, Ibadan, Nigeria, Teaching and 
impacts on broilers’ performance (Feddes et al., 2002, Research farm, from September to November.
El-Deek and Al-Harthi, 2004). Apart from the physical 
stress that could be inflicted on the birds under high SD 
(Thaxton et al., 2006; Estevez, 2007), the metabolism Experimental Design
of the nutrients can also stress the birds due to their 
heat increment, with protein having the highest value, The experimental design was a complete randomized 
and thus affect the birds’ performance negatively. design in a factorial arrangement of 3 x 2 x 3, with three 
Energy and protein are the two main constituents that energy (EM) levels, two crude protein (CP) levels, and 
affect all production parameters in broiler chickens three stocking densities (SD).
(Coillin et al., 2003; Kamran et al., 2008b). Energy is 
required for body functioning and protein is essential 
constituent of all animal body tissue. It is a widely Experimental Diets Formulation
acceptable principle in poultry nutrition that dietary 
energy and essential nutrient must be considered as an The recommended energy level for Arbor Acre 
entity and in a right proportion for optimum growth of commercial broiler starter phase (3080 kcal/kg ME) and 
the birds (Jafarnejad and Sadegh, 2011). Studies have finisher phase (3200 kcal/kg ME) (Aviagen, 2009) were 
been carried out to define the minimum protein varied with 5% above and below to give three energy 
requirement for optimum growth rate in relation to levels while the recommended protein levels of 23% 
energy level (Fetuga, 1984; NRC, 1994; Kamran, et al., and 20% for starter and finisher phase respectively 
2004; Aviagen, 2009). The recommended amounts of where lowered by 5%. Diets were formulated using 
energy and protein in broiler breeding guide books are each of the three energy levels at the two protein levels 
high. Therefore providing recommended energy and to give six diets (Table 1 and 2).
proteins values increases feed prices which are not 
economically viable for poultry units (Bahreiny et al., 
2013). Farmers try to reduce cost per unit products by Stocking Densities
reducing the amount of energy and protein in the feed. 
It is commonly agreed that greater performance in The recommended stocking density of 12 birds/m2 for 
chicks can be achieved if essential amino acids (EAA) Arbor Acre commercial broiler strain raised in open 
in • low crude protein diet were equivalent to those sided house (Aviagen, 2009) was varied with 20% 
needed in the recommended protein diet (Ciftci and above and below to give three stocking densities of 10, 
Ceylon, 2004; Abdel -  Maksoud et al., 2010). 12 and 14 birds per meter square respectively.
Increasing dietary metabolizable energy (ME) 
significantly increases the body weight gain (Zaman et 
al., 2008), reduces feed intake and improves feed Experimental Birds
conversion (Nogueira et al., 2013). Kamran et al. 
(2008a) observed that the reduction in dietary crude Six hundred and twelve (612) one-day-old Arbor Acre 
protein (CP) and metabolizable energy (ME) content broilers were obtained from Ajanla Hatchery, Ibadan, 
leads to a linear increase in feed intake while weight Oyo State, Kligeria. The birds were weighed and 
gain and feed conversion ratio (FCR) are adversely randomly distributed to six brooding units of 102 
affected. However, other authors observed that dilution birds/unit. At the end of day seven, 576 (96 per unit) 
of ME and CP of diet did not affect intake (Nawaz et al., birds were assigned to the various stocking densities at 
2006), live weight, FCR and protein efficiency ratio the rate of eight birds per interaction unit with four 
(PER) (Dairo et al., 2010). replicates each. The experiment lasted for 56days.
Advancement in breeding, genetic improvement and 
changes in the climatic and other environmental 
conditions calls for a constant re-evaluation of broilers Housing and management of birds
SD and their nutrient requirements. This study was 
carried out to examine the effect of varying stocking Birds were housed in an open sided house with 32cm 
density, energy and protein levels and their interaction dwarf wall, with the inside partitioned according to the 
on the growth performances and feed economy of stocking density with 0.05m2/bird provided for feeder 
broiler chicken raised during late wet season in Nigeria. and drinker in each partition. Hanging feeder and an- 
eight-liter water bowl of 30cm diameter were provided 
for each partition from week three. The floor was 
MATERIALS AND METHODS covered with 6cm high wood shaving litters, the litter 
materials were changed at 4th and 6th week. Thermo 
Study area hygrometers were placed at strategic points in the 
house to monitor temperature and humidity.
The experiment was conducted at the poultry unit of the Vaccination and medication were administered as
UNIVERSITY OF IBADAN LIBRARY
Ademulegun and Adeyemo 3
Table 1. Composition of the starter experimental diets for broilers
DIETS
Ingredient
RCP-RME LCP-RME RCP-LME LCP-LME RCP-HME LCP- HME
Maize 49.00 52.00 55.00 56.00 52.15 54.35
Wheat offal 5.00 5.00 4.65 5.00 0 0
FFSB 8.65 8.00 5.00 7.12 9.50 9.50
GNC 25.00 23.00 25.00 22.00 23.5 22.00
Fish Meal 4.00 3.55 5.00 4.50 5.00 4.50
Palm oil 3.00 3.00 0 0 4.50 4.30
Bone Meal 3.00 3.00 3.00 3.00 3.00 3.00
Oyster shall 1.50 1.50 1.50 1.50 1.50 1.50
Salt [NaCI] 0.25 0.25 0.25 0.25 0.25 0.25
Broiler Premix 0.25 0.25 0.25 0.25 0.25 0.25
DL -Meth: 0.10 0.11 0.10 0.10 0.10 0.10
L-Lysine 0.25 0.34 0.25 0.28 0.25 0.25
Total 100 100 100 100 100 100
Determined Nutrients
Crude Protein 23.03 21.74 23.40 21.92 23.13 21.80
ME[keal/kg] 3106 3112 2928 2933 3217 3220
Calculated Nutrients
L-Lysine 1.20 0.20 1.20 1.20 1.20 1.20
DL -Meth: 0.45 0.45 0.46 0.45 0.46 0.45
Cal;Pr 135 143 125 134 139 148
Ca 1.93 1.90 1.99 1.96 1.99 1.95
Avail. P 0.71 0.70 0.71 0.71 0.67 0.66
RCM-RME, Recommended protein &energy; LCP-RME, Lower protein & Recommended energy; RCP-LME, 
Recommended protein & lower energy; LCP-LME, Lower protein &lower energy; RCP-HME, Recommended 
protein & higher energy; LCP-HME, Lower protein & high energy; FFSB, Full fat soya bean; GNC, Ground nut 
cake; Ca, Calcium; Avail. P, Available Phosphorus.
recommended by the hatchery operator. Feed and Software 9.2 (SAS 2008). Significantly different means 
water were supplied ad libitum. Records of feed intake were separated using Duncan Multiple Range (DMR) 
and birds’ weight were taken weekly, while mortality test, with level of significance set at p < 0.05.
record was taken daily. The following parameters were 
calculated; feed intake (FI, g), weight gain (WG, g) feed RESULTS
conversion ratio (FCR), survival rate (SR, %), and live 
weight per area (LW/m2), feed cost per kglive weight The mean temperature and relative humidity of the 
(FC/kglw) and feed cost per dressed weight (FC/kgdw). poultry house were 27.8 °C and 75.47 %, respectively.
The interaction EM x CP levels x SD affected the feed 
Carcass Yield Evaluation intake and the highest value was obtained using diets 
with low EM and CP levels (Table 3) Treatments did not 
At the end of week eight, 18 birds per stocking density affect (p>0.05) the survival rate, however, SD at 
(equivalent to 19 birds per diet) with weight close to the 12birds/m2 resulted in the best values (p<0.05) of FLW 
average of the group were selected, fasted over night, (2272.21g), WG (2230.71g) and FCR (2.10) and the 
sacrificed, scalded in hot water, defeathered and use of diet with lower CP and EM increased (p<0.05) 
eviscerated. The prima cuts and abdominal fat were FLW (2353.42g) and WG (2312.42g), but the best 
separated, weighed and expressed as percentage of values for FCR were obtained with diets with 
live weight, (Shahin and Elazeem, 2005). recommended CP and high EM, and lower CP and high 
EM (Table 4).
Statistical Analysis The carcass yield was affected (p<0.05) by the 
interaction EM x CP levels x SD, with the lowest value 
Data generated where subjected to analysis of variance (67.33%) found with birds raised under SD at 10 
(ANOVA) using General Linear Model (G LM )ofSAS birds/m2 and diets with lower CP and recommended EM
UNIVERSITY OF IBADAN LIBRARY
J. Anim. Sci. Vet. Med. 4
Table 2. Compositions of the finisher experimental diets for broilers
DIETS
Ingredient RCP-RME LCP-RME RCP-LME LCP-LME RCP-HME LCP-HME
Maize 58.50 59.00 58.50 59 59.74 60.68
Wheat offal 2.00 3.30 5.04 6.00 0 0
FFSB . 15.40 16.07 12.00 12.00 18.00 18.00
GNC 15.00 12.50 17.50 16.02 12.00 11.00
Palm oil 3.81 3.80 1.60 1.6 5.00 5.00
Bone Meal 3.00 3.00 3.00 3.00 3.00 3.00
Oyster shall 1.50 1.50 1.50 1.50 1.50 1.50
Salt [NaCI] 0.25 0.25 0.25 0.25 0.25 0.25
Broiler Premix 0.25 0.25 0.25 0.25 0.25 0.25
DL -Meth: 0.11 0.13 0.11 0.13 0.11 0.12
L-Lysine 0.18 0.20 0.25 0.25 0.15 0.20
Total 100 100 100 100 100 100
Determined Nutrients
Crude Protein 20.11 19.01 20.24 19.14 20.29 19.00
ME[kcal/kg] 3231 3235 3096 3095 3356 3362
Calculated Nutrients
L-Lysine 1.04 1.01 1.03 0.02 1.00 1.02
DL -Meth: 0.40 0.41 0.40 0.41 0.40 0.41
Cal;Pr 161 170 153 162 165 177
Ca 1.68 1.68 1.68 1.68 1.68 1.68
Avail. P 0.63 0.64 0.65 0.66 0.61 0.61
RCM-RME, Recommended protein &energy; LCP-RME, Lower protein & Recommended energy; RCP-LME, 
Recommended protein & lower energy; LCP-LME, Lower protein &lower energy; RCP-HME, Recommended 
protein & higher energy; LCP-HME, Lower protein & high energy; FFSB, Full fat soya bean; GNC, Ground nut 
cake; Ca, Calcium; Avail. P, Available Phosphorus.
levels (Table 5). had the best (p<0.05) productive performance. Birds on 
The use of SD12 birds/m2 caused a reduction (p<.05) the higher density might not have been able to liberate 
on the back cut (14.22%) compared to the use of 14 enough heat for optimum growth, since adequate feed 
birds/m2 (15.33%). The diets with low CP and EM, low intake and uninterrupted emission of heat are 
CP and recommended EM, and recommended CP and necessary for intensive growth rate (Yadgari et al., 
low EM, decreased (p<0.05) abdominal fat relative 2006), and birds under the lower stocking density 
weight (Table 6). (10birds/m2) must have wasted energy for growth on 
The lowest live weight and carcass weight per square excessive exercise. The lack of the effect (p>0.05) on 
meter (p<0.05) were observed with SD at 10 birds/m2 , the FI agrees with the observation of Beloor et al. 
while lowest feed cost per kilogram of live weight and (2010) and is probably due to the sumptuous feeding 
per kilogram of carcass weight were obtained with SD and drinking space provided (0.24m) per bird in all the 
12birds/m2. Carcass weight per square meter and feed stocking densities. Insufficient feeding space has been 
cost per carcass weight were not affected (p>0.05) by attributed to be the cause of reduced FI at high SD 
the CP and EM levels, however, diets with (Estevez et al., 2007; Simsek et al., 2009). In 
recommended CP and energy levels resulted in lower consonance with most authors (Ravindran et al., 2006; 
(p<0.05) live weight per square meter. Diets with Buijs, et al., 2009, Sekeroglu et al., 2011) there was no 
recommended CP and EM levels, and low CP and statistical dependence (p>0.05) of survival rate on SD, 
recommended EM increased (p<0.05) the feed cost per (p>0.05). The diet with lower energy and protein levels 
live weight (Table 7). had the highest (p<0.05) FI, FLW and WG (p<0.05). 
This was in agreement with the observation of 
Bregendahl et al. (2002) who found significant increase 
Discussion in FI by broiler chicks fed on diet with 20% CP 
supplemented with amino acids, compared to the ones 
Birds raised under the recommended SD (12 birds/m2) fed with 23% CP diet, and the report of Abdel-Maksoud
UNIVERSITY OF IBADAN LIBRARY
Ademulegun and Adeyemo 5
Table 3. Effect of the interaction among stocking density, energy and crude protein levels on growth performance of 
broilers at 56 days of age, during the late wet season.
SD(bird/m2) DIETS FLW (g) WG (g) F I  ( 9 ) FCR SR (%)
10 RCP-RME 2099.60 2058.60 4708.51cde 2.24 96.88
LCP-RME 2081.50 2039.5 4682.00de 2.26 93.75
RCP-LME 2173.00 2132.00 4758.79bcd 2.20 93.75
LCP-LME 2292.50 2251.50 5172.43s 2.26 100.00
RCP-HME 2265.00 2223.00 4608.73de 2.03 93.75
LCP-HME 2239.50 2197.50 4426.33e 1.98 93.75
12 RCP-RME 2272.50 2231.50 5010.813bc 2.21 96.88
LCP-RME 2232.50 2190.50 4854.26bcd 2.18 100.00
RCP-LME 2175.50 2134.50 4659.45de 2.14 100.00
LCP-LME 2429.50 2388.50 5084.82sb 2.10 96.88
RCP-HME 2232.00 2190.00 4414.35s 1.98 96.88
LCP-HME 2291.25 2249.25 4601,95de 2.01 96.88
14 RCP-RME 2028.00 1987.00 4516.72de 2.23 93.75
LCP-RME 2131.25 2089.25 4849.51bcd 2.28 96.88
RCP-LME 2092.75 2051.75 4623.39de 2.21 100.00
LCP-LME 2338.25 2297.25 5191.28s 2.22 93.75
RCP-HME 2225.00 2183.00 4730.94cd 2.13 90.63
LCP-HME 2180.00 2138.00 4677.53de 2.15 100.00
SEM 16.53 16.53 34.10 0.015 3.92
a,b,c,d,e: Means on the same row with different superscripts are significantly different (p<0.05). RCM-RME, 
Recommended protein &energy; LCP-RME, Lower protein & Recommended energy; RCP-LME, Recommended 
protein & lower energy; LCP-LME, Lower protein & lower energy; RCP-HME, Recommended protein & higher energy; 
LCP-HME, Lower protein & high energy; SEM, Standard error of means; SD, stocking density; FLW, final live weight 
WG, weight gain; FI, feed intake; FCR, feed conversion ratio; SR, survival rate.
Table 4. Effect of stocking density, energy and crude protein levels on growth performance of broilers at 56 days of 
age during late wet season.
SD (bird/m2) FLW (g)/bird/56days WG (g) FI (g)/bird/56days FCR SR (%)
10 2186.16b 2146.68b 4725.11 2.16s 95.31
12 2272.21s 2230.71s 4771.11 2.10b 97.92
14 2171,87b 2130.35b 4775.68 2.20s 95.83
SEM 16.53 16.53 34.1 0.01 1.6
Diet
REC-RME 2139.33b 2098.33b 4761.33cb 2.23s 95.83
LCP-RME 2148.42b 2106.42b 4795.26b 2.24s 96.88
LCP-LME 2147.08b 2106.08b 4680.54bcd 2.19s 97.92
LCP-LME 2353.42s 2312.42s 5149.51s 2.19s 96.88
RCP-HME 2240.67b 2198.67b 4584.34cd 2.05b 93.75
LCP-HME 2237.92b 2194.92b 4568.61d 2.04b 96.88
SEM 33.26 33.26 34.1 0.03 2.26
a,b,c, Means on the same row with different superscripts are significantly different (p<0.05). RCM-RME- 
Recommended protein &energy; LCP-RME, Lower protein & Recommended energy; RCP-LME, Recommended 
protein & lower energy; LCP-LME, Lower protein Slower energy; RCP-HME, Recommended protein & higher 
energy; LCP:HME, Lower protein & high energy. SEM, Standard error of means; SD, stocking density; FLW, final 
live weight; WG, weight gain; FI, feed intake; FCR, feed conversion ratio; SR, survival rate.
et al. (2010) that high dietary protein reduces FI. Other consonance with the highest FLW and WG by birds fed 
authors (Kamran et al., 2004; Nawaz et al., 2006) noted low EM and CP in this work, Abdel-Maksoudet al. 
that dilution of ME and CP in the diet did not affect FI. In (2010) verified that birds fed 21%CP supplemented with
UNIVERSITY OF IBADAN LIBRARY
J. Anim. Sci. Vet. Med. 6
Table 5: Effect of the interaction among stocking density, energy and protein levels on carcass traits of broilers chicken during 
late wet season
SD (birds/m2) DIET DW (%) Prime cuts (%) AF (%)
TH DS BR BK WNG
10 RCP-RME 73.67abc 12 11.67 18.33 15.33 8.00 2.00
LCP-RME 67.33e 10.67 10.33 17.00 14.67 7.67 2.67
RCP-LME 71.67abcd 11.67 11.00 19.33 15.00 7.33 1.67
LCP-LME 70.67cd 10.67 11.00 18.00 15.00 7.67 2.00
RCP-HME 73.40abcd 11.33 11.00 19.33 15.33 8.00 3.23
LCP-HME 73.67cd 11.33 10.67 20.67 15.00 8.00 3.23
12 RCP-RME 74.33a 11.67 11.00 19.33 14.33 8.33 2.88
LCP-RME 72.67abcd 11.33 11.00 18.33 14.67 7.67 3.07
RCP-LME 73.43abcd 12.33 10.67 19.67 14.33 7.67 2.54
LCP-LME 73.33abcd 10.67 10.00 20.00 14.67 7.33 2.20
RCP-HME 70.50abcd 11.33 11.00 18.67 12.00 8.33 2.50
LCP-HME 71.07bcd 10.33 10.33 20.00 15.33 7.00 2.51
14 RCP-RME 72.93abcd 11.33 11.33 18.00 14.67 7.67 2.91
LCP-RME 72.67abcd 11.33 11.67 17.67 15.00 8.00 1.82
RCP-LME 73.50abcd 12.00 11.00 18.33 16.33 8.00 2.38
LCP-LME 73.83ab 11.33 11.00 19.33 15.67 8.00 2.06
RCP-HME 71.00bcd 11.00 11.00 17.33 15.00 8.00 2.43
LCP-HME 73.67abc 11.67 10.33 20.00 15.33 8.67 2.93
SEM 1.06 0.51 0.42 1.21 0.75 0.28 0.36
a,b,c,d, Means on the same row with different superscripts are significantly different (p<0.05). RCP-RME, Recommended protein 
&energy; LCP-RME, Lower protein & Recommended energy; RCP-LME, Recommended protein & lower energy; LCP-LME, 
Lower protein &lower energy; RCP-HME, Recommended protein & higher energy; LCP-HME, Lower protein & high energy; SEM, 
Standard error of means; SD, stocking density; DW, dressed weight; TH, thigh; DS, drum stick; BK, back; WNG, wing; AF, 
abdominal fat.
Table 6: Effects of stocking density, energy and protein levels on carcass traits of broilers at 56 days of age, raised during late wet
season.
Prime cuts (%)
SD (bird/m2) LW (g) DW (%)
TH DS BR BK WNG AF (%)
10 2086.11 71.73 11.28 10.94 18.78 15.06ab 7.78 2.47
12 2188.89 72.56 11.28 10.67 19.33 14.22b 7.72 2.62
14 2044.44 73 11.44 11.06 18.44 15.33a 8.06 2.42
SEM 43.686 0.434 0.208 0.173 0.494 0.304 0.116 0.148
Diet
RCP-RME 2061.11 73.64a 11,67ab 11,33a 18.56ab 14.78 8.00 2 eoab
LCP-RME 2077.78 70.89° 11.11ab 17.67b 14.78 7.78 2.52ab
RCP-LME 2022.22 72.87ab 12.00a 10.89ab 19.11ab 15.22 7.67 2.20b
LCP-LME 2205.56 72.61abc 10.89° 10.67ab 19.10sb 15.11 7.67 2.09b
LCP-HME 2111.11 71,63bc 11,22ab 11,00ab 18.44ab 14.11 8.10 2.7ab
RCP-HME 2161.11 72.80ab 11.11ab 10.44° 20.22a 15.22 7.89 2.89a
SEM 61.781 0.164 0.294 0.244 0.698 0.43 0.164 0.21
a,b,c, Means on the same row with different superscripts are significantly different (p<0.05). RCP-RME, Recommended protein 
&energy; LCP-RME, Lower protein & Recommended energy; RCP-LME, Recommended protein & lower energy; LCP-LME, 
Lower protein &lower energy; RCP-HME, Recommended protein & higher energy; LCP-HME- Lower protein & high energy; SEM, 
Standard error of means ; SD, stocking density; LW, live weights; DW, dressed weight; TH, thigh; DS, drum stick; BK, back; 
WNG, wing; AF, abdominal fat.
essential amino acids showed the highest body weight mented, 19%CP supplemented and 21% not supple­
compared to other treatments (23% CP not supple­ mented with amino acids). However, in contrast to this
UNIVERSITY OF IBADAN LIBRARY
Sra3
OO
Ademulegun and Adeyemo 7
Table7. Effect of stocking density, energy and protein levels on meat production per 
square meter and feed economy of broilers at 56 days of age raised during late wet 
season.
SD (bird/m2) LW/m2 (kg) DW/m2 (kg) FC/LW («) FC/DW (M)
10 20.85c 14.40° 214.213 314.94s
12 26.73b 18.91b 208.17b 296.21b
14 29.14a 20.65a 218.60a 323.02a
SEM 0.52 0.53 1.86 7.68
Diet
RCP-RME 24.55b 17.68 223.40a 310.18
LCP-RME 25.083 17.13 222.38a 330.25
RCP-LME 25.27a 17.33 205.54b 304.85
LCP-LME 27.27a 19.23 205.30b 300.36
RCP-HME 25.18a 17.79 213.15b 320.45
LCP-HME 26.09a 18.75 212.20b 302.25
SEM 0.73 0.75 2.64 10.87
a,b,c, Means on the same row with different superscripts are significantly
different(p<0.05). RCP-RME, Recommended protein &energy; LCP-RME-Lower protein & 
Recommended energy; RCP-LME-Recommended protein & lower energy; LCP-LME, 
Lower protein &lower energy; RCP-HME- Recommended protein & higher energy; LCP- 
HME, Lower protein & high energy; SEM, Standard error of means; SD, stocking density; 
LW/m2, live weight per meter square; DW/m2, dressed weight per meter square; FC/LW, 
feed cost per live weight; FC/DW, feed cost per dressed weight.
result, Leeson et al. (1996), Kamran et al. (2008a), raised on different SD ( 5,10.15and.20 birds per m2). In 
(2008b) mentioned that reduction in dietary CP and ME a similar work, Dozier et al. (2005) reported no 
content leads to a linear increase in FI, while WG and difference in relative weight of carcass and abdominal 
FCR were adversely affected. The improved (p<0.05) FI fat due to SD. However, El- Deek and Al-Harthi (2004) 
and WG by birds on low EM and CP diet could be due verified effect of SD on dressing and hind part 
to the reduced heat increment, which was associated percentage, which decreased when broilers were 
with the metabolism of excess protein. Reduced heat stocked at 18 birds/m2 compared to those stocked at 14 
increment leads to reduced heat stress and therefore birds/m2, while those on 10 birds/m2 showed 
improved FI and WG. Birds on high EM and normal CP, intermediate percentage dressing and hind part and a 
and high EM and lower CP had the lower FI and FCR. significantly higher abdominal fat percentage.
This agreed with the observation of Waldroup et al. Dietary energy level did not affect (p>0.05) the 
(1^76) and Skinner et al. (1992) that increasing nutrient percentage of dressed weight and breast meat, and this 
density leads to a significant reduction in feed agrees with the conclusion of Rosa et al. (2007) that 
consumption. Additionally, Nahashon et al. (2005) and higher dietary energy level did not affect the percentage 
Elmansy (2006) showed that FCR was improved with of dressed weight, breast and wing yields. This finding 
increasing energy level during the finishing period. This contrasts with the observation of Nguyen et al. (2010) 
is as a result of the lower percentage of reduction in that higher dietary energy significantly increased 
WG (4.92% and 5.08% for high EM and recommended carcass weight and abdominal fat, but decreased wing 
CP and, high EM low CP respectively, when compared and legs yield.
with the reduction in FI (11% and 11.28% with the same Dilution of both energy and protein did not negatively 
diet) in contrast with low EM and CP diet. depress percentage of dressed weight, drumstick, 
The result of this study shows that the dietary energy breast, back and wing yield, as opposed to the linearly 
levels were sufficient to supply the broilers decreased carcass weight and breast yield of male 
requirements for thermoregulation and growth and did broiler, as diet was diluted for both energy and protein 
not result in any carcass or parts loss. Dressing observed by Lesson et al. (1996).
percentage of thigh, drumstick, breast and abdominal Increase or decrease of either energy or protein did not 
fat were not influenced by SD, and this was in affect (p>0.05) the percentage of thigh, except when 
agreement with the observation of Thomas et al. (2004) both protein and energy were diluted, also increasing 
and Ravindran. et al. (2006) that there is no difference energy and dilution of protein depresses more 
in relative weight of breast and abdominal fats in birds percentage of drumstick than dilution of both. In
UNIVERSITY OF IBADAN LIBRARY
J. Anim. Sci. Vet. Med. 8
essence, the hind limb requires relative high and www.Aviagen.com
balance levels of both energy and protein. Beloor, J., Kang, H. K., Kim, Y. J., Subramani, V. K., Jang, I.
The abdominal fat content was highest for diet with S., Sohn, S. H., & Moon, Y. S. (2010). The effect of stocking 
the highest energy level and lowest for diet with lowest density on stress related genes and telomeric length in 
broiler chickens. Asian-Australasian Journal of Animal 
energy level. This was consistent with Summers et al. Sciences, 23(4), 437-443.
(1992) and Boekholt et al. (1994) who found a reduction Boekholt, H. A., Van Der Grinten, P. H., Schreurs, V. V. A. M., 
in 'fat deposition due to a decrease in dietary energy Los, M. J. N„ & Lettering, C. P. (1994). Effect of dietary 
because excess energy is converted and deposited as energy restriction on retention of protein, fat and energy in 
fat. The lowest percentage of dressed weight at SD 10 broiler chickens. British poultry science, 35(4), 603-614.
birds/m2 and low CP and recommend EM could be due Bregendahl, K., Sell, J. L., & Zimmerman, D. R. (2002). Effect 
to the lowest FLW and WG shown by this group. As of low-protein diets on growth performance and body 
expected, there was an increase in meat production per composition of broiler chicks. Poultry science, 81(8), 11 Se­
area (kg/m2) as a function of SD. This was in agreement l l  67.
with the other authors (Tong et al., 2012; Nogueira et Buijs, S., Keeling, L., Rettenbacher, S., Van Poucke, E., & Tuyttens, F. A. M. (2009). Stocking density effects on broiler 
al., 2013). welfare: Identifying sensitive ranges for different indicators. 
The feed cost per live weight was affected (p<0.05) by Poultry Science, 88(8), 1536-1543.
SD, with the result following the trend of FLW and WG. Ciftci, I., & Ceylan, N. (2004). Effects of dietary threonine and 
Birds on SD 14 birds/m2 had the lower FLW and WG crude protein on growth performance, carcase and meat 
and the highest feed cost per live weight and dressed composition of broiler chickens. British poultry science, 
weight not differing from SD 10 birds/m2, but 45(2), 280-289.
significantly higher than that of 12 birds/m2. However, Collin, A., Malheiros, R. D., Moraes, V. M., Van As, P., 
considering the gross profitability per unit space, using Darras, V. M., Taouis, M., Decuypere, E., & Buyse, J. (2003). Effects of dietary macronutrient content on energy 
monetary returns per meter square minus cost of feed metabolism and uncoupling protein mRNA expression in 
on yield per meter square (Puron et al., 1995) birds on broiler chickens. British Journal of Nutrition, 90(02), 261 - 
SD 12 birds/m2 had the highest value. The feed cost per 269.
live weight was affected by FI, WG and feed cost. While Dairo, F. A. S., Adesehinwa, A. O. K., Oluwasola, T. A., & 
birds on diet with higher energy ate less than birds on Oluyemi, J. A. (2010). High and low dietary energy and 
lower energy, they had a relatively higher weight gain, protein levels for broiler chickens. African Journal of 
thus, the higher feed cost was nullified by the gain, Agricultural Research, 5(15), 2030-2038.
while the feed cost/kg live weight between birds on high Dozier, W. A., Thaxton, J. P., Braihon, S. L., Morgan, G. W., 
and low energy. Birds on low EM and CP had the Miles, D. M„ Roush, W. B„ Lott, B. D., Vizzier-Thaxton, Y. (2005). Effect of stocking on growth performance and 
highest gross profit on feed/unit weight and area. processing yield of heavy broilers. Poultry Science. 
84:1332-1338.
Dozier, W. A, Thaxton, J. P, Purswell, J. L, Olanrewaju, H. A, 
Conclusion Branton, S. L, Roush, W. B. (2006). Stocking density effect 
on male broilers growth to 1.8 kilograms of BW. Poultry 
Broiler chickens may be economically raised at Science. 85:344-351.
stocking density 12birds/m2 and on diet containing Bahreiny, E., Dadvar, P., Morovat, M., & Bujarpoor, M. (2013). 
2933kcal/kgME and 21.92% crude protein for starter Effect of different level of energy to protein ratio and 
phase and 3095 kcal/kgME and 19.14% crude protein breeding system on performance and carcass characteristics of male and female broilers. International 
for finisher phase, during late wet season in South Journal of Agriculture, 3(3), 597 -607.
Western Nigeria. El-Deek, A. A., & Al-Harthi, M. A. (2004).Responses of 
modern broiler to stocking density green tea commercial 
multi enzymes and their interaction on productive 
REFERENCES performance, carcass characteristics. International Journal 
of Poultry Science, 3(10):635-645.
Abdel-Maksoud, A., Yan, F., Cerrate, S., Coto, C., Wang, Z., Elmansy, M. M. (2006). Assessment of the effect of L- 
& Waldroup, P. W. (2010). Effect of dietary crude protein, carhitine supplementation to the diet with different dietary 
lysine level and amino acid balance on performance of energy levels on broiler performance. M.Sc. Thesis, Fac. 
broilers 0 to 18 days of age. International Journal of Poultry Agric, Tanta Univ., Tanta, Egypt.
Science, 9(1), 21-27. Estevez, I. (2007). Density allowance for broilers, where to set 
Abudabos, A. M., Samara, E. M., Hussein, E. O., Mu'ath, Q., the limits. Poultry Science. 86:1265-1272.
& Al-Atiyat, R. M. (2013). Impacts of stocking density on the Feddes, J.J., Emmanuel, E.J., Zuidhof, M. J. (2002). Broiler 
performance and welfare of broiler chickens. Italian Journal performance, body weight variance, feed and water intake 
of Animal Science, 12(1), 11. and carcass quality at different stocking densities. Poultry 
Sekeroglu, A., Sarica, M., Gulay, M. S „ & Duman, M. (2011). Science. 81, 774-779.
Effect of stocking density on chick performance, internal Fetuga B. L. A. (1984). Technique in feed formulation. Paper 
organ weights and blood parameters in broilers. Journal of presented at the feed mill management training workshop, 
Animal and Veterinary Advances, 10(2), 246-250. Department of Agricultural Economics, University of Ibadan.
Aviagen (2009).Arbor Acres plus broiler nutrition specification. Jafarnejad, S., & Sadegh, M. (2011). The effect of different
UNIVERSITY OF IBADAN LIBRARY
Ademulegun and Adeyemo 9
levels of dietary protein, energy and using fat on the Simsek, U. G., Cerci, I. H., Dalkilic, B., Yilmaz, O., & Ciftci, M. 
performance of broiler chicks at the end of the third week. (2009). Impact of stocking density and feeding regimen on 
Asian Journal of Poultry Science, Pp.6. broilers: Chicken meat composition, fatty acids, and serum 
Kamran, Z., Mirza, M. A., & Mahmood, S. (2004). Effect of cholesterol levels. The Journal of Applied Poultry Research, 
decreasing dietary protein levels with optimum amino acids 18(3), 514-520.
profile on the performance of broilers. In Pakistan Skinner, J. T „ Waldroup, A. L., & Waldroup, P. W. (1992). 
Veterinary Journal, 24(4), 165-168. Effects of dietary nutrient density on performance and 
Kamran, Z. M., Sarwar, M., Nisa, M. A., Nadeem, S., Admad, carcass quality of broilers 42 to 49 days of age. The Journal 
5., Mushtaq, T „ Ahmad, T. & Shahzad, M. A. (2008b). of Applied Poultry Research, 1(4), 367-372.
Effect of lowering dietary protein with constant energy to Skrbic, Z., Pavlovski, Z., Lukic, M., Peric, L , & Milosevic, N. 
protein ratio on growth, body composition and nutrient (2009). The effect of stocking density on certain broiler 
utilization of broiler chicks. Asian-Australasian Journal of welfare parameters. Biotechnology in Animal Husbandry, 
Animal Sciences, 21(11), 1629-1634. 25(1-2), 11-21.
Kamran, Z., Sarwar, M., Nisa, M., Nadeem, M. A., Mahmood, Summers, J. D., Spratt, D., Atkinson, J. L. (1992). Broiler 
5., Babar, M. E., & Ahmed, S. (2008a), Effect of low-protein weight gain and carcass composition when fed diets varying 
diets having constant energy-to-protein ratio on in amino acid balance, dietary energy and protein level. 
performance and carcass characteristics of broiler chicken Poultry science, 71(2), 263-273.
from one to thirty-five days of age. Poultry Science. 87:468- Thaxton J. P., Dozier, W. A., Branton, S. L., Morgan, G. W., 
474. Miles D. M., Roush, W. B., Lott, B. D., Vizzier-Thaxton, Y. 
Leeson, S. L., Coston, L., & Summers, J. D. (1996). Broiler (2006). Stocking density and physiological adaptive 
response to energy or energy and protein dilution in the responses of broilers. Poultry science, 85, 819-824.
finisher diet. Poultry Science., 75, 522-528. Thomas, D. G, Ravindran, V., Thomas, D. V., Camden, B. J., 
Nahashon, S. N., Adefope, N., Amehyenu, A., & Wright, D. Cottan, Y. H., Morei, P. C. H., Cook, C. J. (2004). Influence 
(2005) . Effect of dietary metabolizable energy and crude of stocking density on the performance, carcass 
protein concentration on growth performance and carcass characteristics and selected welfare indicators of broiler 
characteristics of French Guinea broilers. Poultry Science. chicken. New Zealand Veterinary Journal, 52, 76-81.
84, 337-344. Tong, H. B., Lu, J., Zou, J. M., Wang, Q., Shi, S. R. (2012). 
Nawaz, H., Mushtaq, T., & Yaqoob, M. (2006). Effect of Effects of stocking density on growth performance, carcass 
varying levels of energy and protein on live performance yield, and immune status of a local chicken breed. Poultry 
and carcass characteristics of broiler chicks. The Journal of science, 91:667-673.
Poultry Science, 43(4), 388-393. Waldroup, P. W., Mitchell, R. J., Payne, J. R., & Johnson, Z. 
Nguyen, T. V., Chaiyapoom, B., & Somchai, C. (2010). Effect B. (1976).Characterization of the response of broiler 
of dietary protein and energy on growth performance and chickens to diets varying in nutrient density content. Poultry 
carcass characteristics of betong chickens ( Gallus Science, 55, 130-145.
domesticus) during Growing Period. International Journal of Yadgari, L., Kinreich, R., Druyan, S., Cahaner, A. (2006). The 
Poultry Science, 9(5), 468-472. effect of stocking density in hot condition on growth, meat 
Nogueira, W. C. L., Velasquez, P. A. T „ Furlan, R. L., Macari, yield and meat quality of featherless and feathered broilers, 
M. (2013). Effect of dietary energy and stocking density on XII European Conference, Verona, Italy. World Poultry 
the performance and sensible heat loss of broilers reared Science Journal, 62, 603.
under Tropical Winter Conditions. Brazilian Journal of Yakubu, A., Ayoade, J. A., & Dahiru, Y. M. (2010), Effects of 
Poultry Science, Vol.15 (1), 53-58. genotype and population density on growth performance, 
NRC (1994). Nutrient Requirements of Poultry, 9th ed. carcass characteristics, and cost-benefits of broiler 
National Academic Press. Washington D.C. USA. chickens in north central Nigeria. Tropical animal health and 
Puron, D., Santamaria, R., Segura, J. C., & Alamilla, J. L. production, 42(4), 719-727.
(1995). Broiler performance at different stocking densities. Zaman, Q. U., Mushtaq, T., Nawaz, H., Mirza, M. A., 
The Journal of Applied Poultry Research, 4(1), 55-60. Mahmood, S., Ahmad, T., Babar, M. E., & Mushtaq, M. M. 
Ravindran, V., Thomas, D. V., Thomas, D. G., & Morel, P. C. H. (2008). Effect of varying dietary energy and protein on 
(2006) . Performance and welfare of broiler as affected by broiler performance in hot climate. Animal feed science and 
stocking density and Zinc bacteracin supplementation. technology, 146(3), 302-312.
Animal Science Journal, 77, 110-116.
Rosa, P. S., Faria Filho, D. E., Dahlke, F., Vieira, B. S., 
Macari, M., & Furlan, R. L. (2007). Effect of energy intake 
on performance and carcass composition of broiler 
chickens from two different genetic groups. Brazilian 
Journal of Poultry Science, 9(2), 117-122.
SAS, (2008). User’s Guide: Statistics. Version 9.2, SAS 
Institute Inc., Cary, NC. USA.
Shahin, K. A., & Abd Elazeem, F. (2005). Effects of breed, sex 
and diet and their interactions on carcass composition and 
tissue weight distribution of broiler chickens. Archiv fur 
Tierzucht, 48(6), 612- 626.
UNIVERSITY OF IBADAN LIBRARY