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Response of broiler chickens from three genetic groups to different stocking densities

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The aim of the present study was to determine the effect of stocking density as a stress factor on production results, blood corticosterone levels and duration of tonic immobility (TI) in broiler chickens from three genetic groups. Chickens were assigned to 6 groups: in groups 1,2 and 3, Ross 308, Hubbard Flex and Hybro broiler chickens were kept at a stocking density of 13 birds/m2, and in groups 4,5 and 6 Ross 308, Hubbard Flex and Hybro broiler chickens were kept at a density of 17 birds/m2, respectively. During the experiment, individual body weight of the chickens, feed consumption, and mortality were recorded at weekly intervals. Blood corticosterone levels were determined and tonic immobility (TI) measured in 7 birds from each group. The results obtained showed that genetic background had no effect on the final body weight of the chickens or feed conversion (kg feed/kg gain), but origin had an effect on blood corticosterone levels. Stocking density had a significant effect on broiler productivity. Increasing the stocking density from 13 to 17 birds/m2 had a negative effect on most production parameters of broilers from all three genetic groups. However, Ross 308 broilers showed the smallest decrease in productivity after stocking density per m2 was increased, possibly suggesting that these birds are less sensitive to this stress factor compared to Hubbard Flex and Hybro chickens. Stocking density had no clear effect on the duration of tonic immobility. There was a tendency towards increased blood corticosterone levels in broilers subjected to higher stocking density per m2.
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RESPONSE OF BROILER CHICKENS FROM THREE GENETIC GROUPS
TO DIFFERENT STOCKING DENSITIES**
Iwona Skomorucha, Renata Muchacka, Ewa Sosnówka-Czajka,
Eugeniusz Herbut
Department of Technology, Ecology and Economics of Animal Production, National Research Institute
of Animal Production, 32-083 Balice n. Kraków, Poland
Abstract
The aim of the present study was to determine the effect of stocking density as a stress factor on pro-
duction results, blood corticosterone levels and duration of tonic immobility (TI) in broiler chickens
from three genetic groups. Chickens were assigned to 6 groups: in groups 1, 2 and 3, Ross 308, Hub-
bard Flex and Hybro broiler chickens were kept at a stocking density of 13 birds/m2, and in groups
4, 5 and 6 Ross 308, Hubbard Flex and Hybro broiler chickens were kept at a density of 17 birds/m2,
respectively. During the experiment, individual body weight of the chickens, feed consumption, and
mortality were recorded at weekly intervals. Blood corticosterone levels were determined and tonic
immobility (TI) measured in 7 birds from each group. The results obtained showed that genetic
background had no effect on the final body weight of the chickens or feed conversion (kg feed/kg
gain), but origin had an effect on blood corticosterone levels. Stocking density had a significant ef-
fect on broiler productivity. Increasing the stocking density from 13 to 17 birds/m2 had a negative
effect on most production parameters of broilers from all three genetic groups. However, Ross 308
broilers showed the smallest decrease in productivity after stocking density per m2 was increased,
possibly suggesting that these birds are less sensitive to this stress factor compared to Hubbard
Flex and Hybro chickens. Stocking density had no clear effect on the duration of tonic immobility.
There was a tendency towards increased blood corticosterone levels in broilers subjected to higher
stocking density per m2.
Key words: broiler chickens, productivity, tonic immobility (TI), corticosterone, stocking density
Modern broiler chickens, which show rapid weight gains and good feed conver-
sion, have become more demanding in terms of management, feeding and handling
conditions. The optimization and stabilization of rearing conditions made birds more
delicate and the absence of necessary environmental stimuli (weather conditions,
foraging activity) suppressed the body’s adaptive mechanisms. For this reason,
modern broilers have lower resistance to environmental factors while being more sus-
ceptible to stress states, which has an adverse impact on their productivity and health
(Al-Murrani et al., 2006; Sosnówka-Czajka et al., 2006).
*This work was conducted as part of statutory activity, project no. 4136.1.
Ann. Anim. Sci., Vol. 9, No. 2 (2009) 175–184
I. Skomorucha et al.
176
One of the stress factors of birds is high stocking density, which is often found in
commercial large-scale systems. Campo et al. (2005) report that high stocking density
per m2 makes birds more fearful and susceptible to stress. Increased stocking den-
sity is accompanied by reduced body weight, poorer feed conversion and increased
mortality (Skomorucha et al., 2004; Sosnówka-Czajka et al., 2005; Estevez, 2007;
Onbaşılar et al., 2008).
Stress factors that affect birds also increase blood corticosterone levels (Puva-
dolpirod and Thaxton, 2000; Olanrewaju et al., 2006) and increase the duration of
tonic immobility, which reflects the birds’ welfare and stress levels (Andrews et al.,
1997; Campo et al., 2005; Onbaşılar et al., 2008)
Sensitivity to environmental factors and susceptibility to stress may be genetically
determined (Campo and Carnicer, 1994; Campo et al., 2008; Sosnówka-Czajka et al.,
2005).
The aim of the present study was to determine the effect of stocking density as
a stress factor on production results, blood corticosterone levels and duration of tonic
immobility (TI) in broiler chickens from three genetic groups.
Material and methods
The experiment was carried out at a poultry farm in Aleksandrowice using 810
unsexed broiler chickens of three commercial lines (Ross 308, Hubbard Flex, Hybro)
originating from Poultry Hatcheries in Gardawice and Łężkowice.
After weighing and tagging, chicks were placed in cage batteries, in which each
cage with an area of 1 m2 was a replicate:
Genetic group
Ross 308 Hubbard
Flex Hybro Ross 308 Hubbard
Flex Hybro
Group I II III IV V VI
No. of replicates 9 9 9 9 9 9
Stocking density (bird/m2) 13 13 13 17 17 17
Chickens were fed ad libitum diets based on concentrates: starter diet to 21 days of
age (3000 kcal metabolizable energy, crude protein 21.7%, lysine 1.15%, methionine
+ cystine 0.82% per kg feed), grower diet from 22 to 35 days (ME 3100 kcal, CP
19.8%, lysine 0.96%, methionine + cystine 0.78% per kg feed), and finisher diet to
42 days (ME 3100 kcal, CP 18.5%, lysine 0.82%, methionine + cystine 0.71% per kg
feed). Throughout the experiment, birds had free access to water drinkers.
During the study, individual body weight of the chickens, feed consumption in
groups (replicates) and mortality were recorded every week. At 1, 21 and 42 days of
rearing, blood was collected from 7 birds of each group to determine corticosterone
levels, which were tested immunoenzymatically using a Diagnostic System Laborato-
ries kit (USA) and a SIRIO S immunoenzymatic analyser.
Response of broiler chickens to different stocking densities 177
At 21, 28, 35 and 42 days of rearing, tonic immobility (TI) was measured accord-
ing to the method of Akşit et al. (2006) in 7 birds from each group.
The results were analysed statistically by two-way analysis of variance and signifi-
cant differences were estimated using Duncan’s test.
Results
Tables 1–3 give mean results for the experimental groups.
Broilers’ rearing results are shown in Table 1. On day 1 of rearing, the lowest body
weight was characteristic of Hybro broilers compared to the other groups (P≤0.01).
At 21 days of rearing, the highest body weight at a stocking density of 13 birds/m2
was found in Hubbard Flex broilers compared to the other groups (P≤0.01), and at
a density of 17 birds/m2 Ross 308 and Hubbard Flex broilers weighed 911 g compared
to 860 g in Hybro chickens, with a highly significant difference. Comparison of body
weight in chickens from the same genetic group that were kept at different stocking
densities per m2 showed a highly significant difference between Hubbard Flex chick-
ens stocked at 13 birds/m2 (group II) and 17 birds/m2 (group V) and between Hybro
chickens stocked at 13 birds/m2 (group III) and 17 birds/m2 (group VI). On the final
day of the experiment, broiler chickens reared at a stocking density of 13 birds/m2
obtained final body weights of 2527, 2540 and 2532 g, respectively, and when stock-
ing density per m2 was higher, Hubbard Flex chickens were the lightest and Ross 308
chickens the heaviest (P≤0.01). Comparison of the birds from the same genetic group
that were kept at different stocking densities showed differences in body weight be-
tween Hubbard Flex chickens (P≤0.01) and between Hybro chickens (P≤0.05).
The poorest feed conversion per kg weight gain (Table 1) in groups at
a stocking density of 13 birds/m2 was found in Hybro broilers and the highest in
Ross 308 broilers (P≤0.01). At 17 birds/m2 no statistically significant differences were
found between the groups. A highly significant difference was found when comparing
Hybro broilers at densities of 13 and 17 birds/m2. In the grower period, a difference
emerged between Hubbard Flex and Hybro chickens raised at a density of 13 birds/m2
(P≤0.01). At a density of 17 birds/m2, no significant differences were found be-
tween the groups. Comparison of broilers in terms of stocking density per m2 showed
a highly significant difference in Hubbard Flex chickens between densities of
13 birds/m2 (group II) and 17 birds/m2 (group V), and a significant difference in Ross
308 chickens between groups I (stocking density of 13 birds/m2) and IV (stocking
density of 17 birds/m2). For the whole rearing period, the best feed conversion per kg
weight gain at a density of 13 birds/m2 was found in Hubbard Flex broilers and the
poorest in Hybro broilers (P≤0.01). No statistically significant differences emerged
between the groups for a density of 17 birds/m2. Highly significant differences in
feed conversion were found between Hubbard Flex and Hybro chickens stocked at
a density of 13 birds/m2 and Hubbard Flex and Hybro chickens stocked at a density of
17 birds/m2. Ross 308 broilers raised at a density of 13 birds/m2 were characterized by
better feed conversion per kg weight gain compared to chickens of the same genetic
group that were reared at a higher stocking density per m2 (P≤0.05).
I. Skomorucha et al.
178
Table 1. Productive results of broiler chickens
Item Days of
rearing
Group
Genetic
group
(A)
Stocking
density
(B)
A×B
13 birds/m217 birds/m2
I
Ross 308
II
Hubbard Flex
III
Hybro
IV
Ross 308
V
Hubbard Flex
VI
Hybro
Body weight (g) 1 45.36±0.43
B
44.73±0.41
BX
39.13±0.34
A
45.47±0.36
B
46.21±0.39
B Y
39.58±0.32
A
<0.01
21 899.61±10.72
A
975.36±15.04
B X
926.97±9.24
AX
911.19±7.58
B
910.71±13.44
B Y
859.68±8.85
AY
<0.01 <0.01 <0.01
42 2527.21±35.21 2540.32±30.05
X
2532.46±34.77
x
2468.93±31.67
B
2324.81±29.39
Aa Y
2436.45±34.94
by
NS <0.01 <0.05
Feed conversion
(g feed/kg gain)
1–21 1494.00±42.38
Bb
1412.00±20.35
a
1376.00±12.88
A X
1454.00±9.27 1442.00±9.69 1498.00±21.31
Y
NS <0.05 <0.01
22–42 1776.00±36.55
x
1710.00±15.81
A X
1910.00±59.16
B
1956.00±36.28
y
2042.00±27.46
Y
2000.00±80.12 NS <0.01 NS
1–42 1674.00±16.00
Bx
1600.00±10.95
Aa X
1702.00±34.55
B X
1768.00±18.28
y
1808.00±17.15
Y
1812.00±40.42
Y
NS <0.01 NS
Mortality
(%)
1–21 0 0 1.5 0 0 2.3
22–42 3 1.5 4.6 1.2 2.4 6.9
1–42 3 1.5 6.1 1.2 2.4 9.2
A,b,A,B – significant differences between genetic groups of broilers within stocking density.
x,y,X,Y – significant differences between different stocking densities.
a,b,x,y – values in rows with different letters differ significantly (P≤0.05).
A,B,X,Y – values in rows with different letters differ highly significantly (P≤0.01).
Response of broiler chickens to different stocking densities 179
Table 2. Tonic immobility of broiler chickens (s)
Days of
rearing
Group
Genetic
group
(A)
Stocking
density
(B)
A × B
13 birds/m2 17 birds/m2
I
Ross 308
II
Hubbard Flex
III
Hybro
IV
Ross 308
V
Hubbard Flex
VI
Hybro
21 163.57±57.26 113.14±47.29 X 168.14±58.67 283.00±67.90 430.00±74.32 BY 167.71±45.68 A NS ≤0.01 ≤0.05
28 216.29±67.75 313.14±100.78 148.43±83.33 386.71±88.05 174.43±76.52 234.29±82.01 NS NS NS
35 318.71±95.31 198.29±67.62 287.29±87.07 303.43±85.48 189.71±74.12 341.86±94.07 NS NS NS
42 307.71±66.41 307.57±92.15 x 301.43±79.85 198.00±69.13 94.29±28.49 y 185.57±54.05 NS ≤0.05 NS
A,b,A,B – significant differences between genetic groups of broilers within stocking density.
x,y,X,Y – significant differences between different stocking densities.
a,b,x,y – values in rows with different letters differ significantly (P≤0.05).
A,B,X,Y – values in rows with different letters differ highly significantly (P≤0.01.)
Table 3. Blood corticosterone levels in broiler chickens (ng/ml)
Days of
rearing
Group
Genetic
group
(A)
Stocking
density
(B)
A × B
13 birds/m217 birds/ m2
I
Ross 308
II
Hubbard flex
III
Hybro
IV
Ross 308
V
Hubbard flex
VI
Hybro
1 315.48±23.04 B 94.96±36.19 A 59.70±57.94 A 321.42±49.56 B 93.86±62.81 A 46.12±13.63 A ≤0.01 - -
21 264.27±71.31 x 181.47±65.26 126.06±63.33 498.34±96.60 By 321.93±69.44 152.27±60.71 A ≤0.01 ≤0.05 NS
42 232.17±60.93 b 96.16±31.44 AaX 365.11±20.85 Bc 309.00±42.50 297.94±29.20 Y 345.67±23.47 ≤0.01 ≤0.01 ≤0.05
For significant differences, see tables above.
I. Skomorucha et al.
180
The highest mortality was characteristic of Hybro chickens stocked at both densi-
ties (Table 1). The lowest mortality was found in group II (Hubbard Flex) for a den-
sity of 13 birds/m2 and in group IV (Ross 308) for a density of 17 birds/m2. Among
Hubbard Flex and Hybro broilers, mortality was lower when birds were stocked at
13 birds/m2 compared to 17 birds/m2.
The duration of tonic immobility is presented in Table 2. At 21 days of the study,
no significant differences were found between the groups for a stocking density of
13 birds/m2. At a density of 17 birds/m2, a highly significant difference emerged be-
tween Hubbard Flex and Hybro chickens. Comparison of broiler chickens from the
same genetic group that were kept at different densities per m2 showed a difference
between Hubbard Flex broilers (P≤0.01). At 28 and 35 days of the experiment, no
statistically significant differences were found between the groups in the duration of
tonic immobility. At 42 days of the experiment, a difference emerged between Hub-
bard Flex chickens reared at different densities per m2 (P≤0.05).
Blood corticosterone levels were dependent on both the commercial line and
stocking density (Table 3). On day 1 of rearing, the highest corticosterone level
was characteristic of Ross 308 chickens compared to the other groups (P≤0.01). At
21 days of the experiment, corticosterone level was still the highest in Ross 308 broil-
ers, with a highly significant difference found for a density of 17 birds/m2 between Ross
308 and Hybro chickens. Birds from the groups stocked at 17 birds/m2 tended to have
higher blood corticosterone levels, but a significant difference emerged only between
Ross 308 chickens. At 42 days of the experiment, the highest corticosterone level at
a density of 13 birds/m2 was characteristic of Hybro broilers and the lowest of Hub-
bard Flex broilers (P≤0.01). At a density of 17 birds/m2 no statistically significant dif-
ferences were found between the groups in blood corticosterone levels. Comparison
of broilers stocked at 13 and 17 birds/m2 showed a highly significant difference in
Hubbard Flex chickens.
Discussion
Good results in poultry production are largely dependent on the choice of proper
genetic material and appropriate stocking density per m2. The literature suggests that
broiler chickens of different origin have different production results (Sosnówka-Czaj-
ka et al., 2005; Skomorucha et al., 2007). According to Smith et al. (1998), broiler
chickens from different genetic groups differ in rate of growth, final body weight,
feed consumption, and feed conversion (kg feed/kg gain). In our study, genetic group
had a statistically significant effect on the body weight of chickens at 1 and 21 days of
the experiment. At 42 days of rearing, chickens stocked at 13 birds/m2 were charac-
terized by similar body weight, and for those stocked at 17 birds/m2, the lowest body
weight was found for Hubbard Flex broilers and the highest for Ross 308 broilers
(P≤0.01). No differences in weight gains and body weight of chickens from three dif-
ferent genetic groups were reported by Reiter and Kutritz (2001). In our study, genetic
group had no effect on feed conversion. However, for lower stocking density per m2,
highly significant differences were found in feed conversion between Hybro and Ross
Response of broiler chickens to different stocking densities 181
308 broilers during the starter period and between Hybro and Hubbard Flex broilers
during the grower period and for the whole experimental period. Skomorucha et al.
(2007) showed the effect of genetic group on feed conversion in broiler chickens.
Likewise, Sosnówka-Czajka et al. (2005) found differences in feed conversion between
Hybro G and Hybro PN chickens. Reiter and Kutritz (2001) also found differences
in feed conversion between Ross and Lohmann Meat and Hubbard broilers, but ob-
served no differences between Lohmann Meat and Hubbard broiler chickens.
Campo et al. (2008) showed differences in the duration of tonic immobility (TI)
between chickens of Red Villafranquina and White-Faced Spanish breeds. In our
study, genetic group had no effect on the duration of TI, but origin had an effect on
blood corticosterone levels.
Increasing the stocking density per m2 in intensive poultry production systems is
aimed to reduce production costs, but often causes stress to the birds, which may af-
fect their productivity. Onbaşılar et al. (2008) showed that stocking rate has an effect
on the final body weight of broiler chickens (P≤0.01), feed consumption (P≤0.05)
and feed conversion (kg feed/kg gain) (P≤0.05). Likewise, Feddes et al. (2002) re-
ported lower body weights in broilers when stocking density increased from 14 to
18 birds/m2. Also Dozier et al. (2006) stated that densities exceeding 30 kg body
weight per m2 of floor space had a negative effect on weight gains and dressing per-
centage of pullets, but had no effect on the physiological indicators of stress. In our
study, we found decreases in the body weight of Hubbard Flex (by 6.67%) and Hybro
broilers (by 7.23%) at 21 days of the experiment and in the final body weight (by
8.46% at P≤0.01 and by 3.79% at P≤0.05) when stocking density increased from
13 to 17 birds/m2. This was paralleled by increases in feed conversion (kg feed/kg
gain) and mortality of broiler chickens from two genetic groups. Skomorucha et al.
(2004) found a decrease in feed consumption by broilers as stocking density increased
from 12 to 18 birds/m2. In the present study, the productivity of Ross 308 broilers
did not deteriorate when stocking density per m2 increased. Likewise, Thomas et al.
(2004) reported similar body weights, feed conversion and mortality for broiler chick-
ens stocked at 10, 15 and 20 birds/m2. Also Pettit-Riley and Estevez (2001) found no
effect of increasing stocking rate from 10 to 20 birds/m2 on body weight and feed
conversion.
Estevez (2007) reports that stocking density is associated not only with produc-
tion results but also with physiological stress in birds. Onbaşılar et al. (2008) showed
longer duration of tonic immobility in broiler chickens stocked at 17.5 birds/m2 com-
pared to 11.9 birds/m2. Likewise, Andrews et al. (1997) found that higher density per
m2 has an effect on longer duration of TI in broiler chickens. In our study, longer du-
ration of TI was only found at 21 days of the experiment for the higher stocking den-
sity of Hubbard Flex chickens. At 42 days of rearing, broilers from all three genetic
groups tended to show short duration of TI at 17 birds/m2 compared to 13 birds/m2,
although the difference occurred for Hubbard Flex chickens only. Also Skomorucha
and Muchacka (2007) showed no effect of stocking density on the duration of TI.
Meanwhile, Thaxton et al. (2006) found that stocking density increased from 20 to
50 kg body weight per m2 has no effect on the blood concentrations of corticosterone,
glucose and cholesterol in broiler chickens, which is evidence that these birds show
I. Skomorucha et al.
182
no stress reaction. In our study, broiler chickens showed a tendency towards higher
blood corticosterone concentrations when stocked at the higher density per m2. On the
final day of the experiment, chicken body weight per unit area was about 33 kg/m2
in the groups stocked at the lower density and ranged from 39.5 to 42 kg/m2 in the
groups stocked at the higher density. Statistically significant differences were found at
21 days of rearing between Ross 308 broilers (P≤0.05) and at 42 days of rearing be-
tween Hubbard Flex broilers (P≤0.01).
In summary, the genetic background of the broiler chickens had no effect on the
final body weight or feed conversion (kg feed/kg gain), but origin had an effect on
blood corticosterone levels.
Stocking density had a significant effect on broiler productivity. Increasing the
stocking density from 13 to 17 birds/m2 had a negative effect on most production pa-
rameters of broilers from all three genetic groups. However, Ross 308 broilers showed
the smallest decrease in productivity after stocking density per m2 was increased,
possibly suggesting that these birds are less sensitive to this stress factor compared to
Hubbard Flex and Hybro chickens.
Stocking density had no clear effect on the duration of tonic immobility, but there
was a tendency towards increased blood corticosterone levels in broilers subjected to
higher stocking density per m2.
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Accepted for printing 9 V 2009
IWONA SKOMORUCHA, RENATA MUCHACKA, EWA SOSNÓWKA-CZAJKA,
EUGENIUSZ HERBUT
Reakcja kurcząt brojlerów z trzech grup genetycznych na zróżnicowaną gęstość obsady podłogi
STRESZCZENIE
Celem przeprowadzonych badań było określenie wpływu gęstości obsady, jako czynnika stresowe-
go, na wyniki produkcyjne, poziom kortykosteronu we krwi oraz czas trwania tonicznego bezruchu (TI)
kurcząt brojlerów trzech grup genetycznych.
Kurczęta brojlery przydzielono do 6 grup: w grupie 1, 2 i 3 utrzymywano odpowiednio: kurczęta
brojlery Ross 308, Hubbard flex i Hybro o obsadzie 13 szt./m2, natomiast w grupie 4, 5 i 6 odpowiednio:
kurczęta brojlery Ross 308, Hubbard flex i Hybro o obsadzie 17 szt./m2. Podczas doświadczenia co tydzień
kontrolowano indywidualnie masę ciała kurcząt, zużycie paszy oraz liczbę padłych kurcząt. Oznaczono
również poziom kortykosteronu we krwi i przeprowadzono pomiar tonicznego bezruchu (TI) u 7 ptaków
z każdej grupy.
Na podstawie uzyskanych wyników stwierdzono, że uwarunkowania genetyczne nie miały wpływu
na końcową masę ciała kurcząt brojlerów oraz na wykorzystanie paszy na przyrost 1 kg masy ciała,
odnotowano natomiast wpływ pochodzenia na poziom kortykosteronu we krwi ptaków. Wielkość obsady
miała statystyczny wpływ na produkcyjność kurcząt brojlerów. Zwiększenie obsady z 13 do 17 szt./m2
pogorszyło większość badanych parametrów produkcyjnych kurcząt brojlerów wszystkich trzech grup
genetycznych. Kurczęta brojlery Ross 308 odznaczały się jednak najmniejszym spadkiem produkcyjności
I. Skomorucha et al.
184
przy zwiększeniu obsady na 1 m2 powierzchni, co może świadczyć, że są one mniej wrażliwe na ten czyn-
nik stresowy w porównaniu z kurczętami Hubbard flex i Hybro. Nie wykazano jednoznacznie wpływu
wielkości obsady na czas trwania tonicznego bezruchu, stwierdzono natomiast tendencje do wzrostu pozio-
mu kortykosteronu we krwi ptaków przy wyższej obsadzie na 1 m2 powierzchni.
... The optimal stocking density rate and its interrelationship with the health status and economic parameters has been identified in other poultry species such as broilers under extensive or intensive production conditions. But, SD results were not always conclusive due to the interaction of other experimental factors such as the genetic background of the breed (Skomorucha et al. 2009). ...
... The technical challenges of studying SD rates in quail are as follows: 1) the utilization of a small flock size to determine the SD rate, which differs from the commercial scenario, 2) the insufficient data on housing, type of litter, antibiotic utilization, strain, and environmental conditions (Schmid and Wechsler 1997;Al Homidan and Robertson, 2003;Ravindran et al. 2006;Skomorucha et al. (2009). The interaction of these factors makes it hard to decide the optimal space requirement (Fig. 1). ...
... Nowadays, advancement in the poultry industry leads to an express stocking density as a live body weight kg / m 2 of the floor (Thaxton et al. 2006). In quail, the SD is the number of birds/m 2 in the cage -floor (Skomorucha et al. 2009;Mahrose et al. 2019). So, this different way to express stocking density is due to the smaller yield and different marketing approach of broiler quail compared to broiler chickens. ...
Article
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The quail populations are considered to be one of the largest among the poultry species. Although quail egg and meat production are growing rapidly, still, quail farming practices and welfare aspects are not well established. Stocking density is one of the factors that can significantly affect the welfare, health, and performance of birds, but according to The Expert Group for Technical Advice on Organic Production, no allowed space standards have been reported for new hybrids and different breeds of quail. This review presents an overview of 1) the benefits of egg and meat of quail, 2) the global market of quail products, 3) the factors affecting the stocking density rate, and 4) the effects of stocking density rates and housing systems on the social behavior, welfare, physiological indices, and performance parameters of broiler and laying quail. Conclusively, larger space and enriched aviaries reduce aggressive behavior, and improve the quail welfare and immunological indices. However, the effect of stocking density on some blood biochemical indices and growth performance parameters showed mixed results. A better understanding of the relationship between housing, health, growth performance, and welfare aspects would assist in the implementation of welfare-economic standards for quail production. According to available data, stocking density ranges for broiler and laying Japanese quail are suggested; however, these stocking rates should be tested under different conditions
... Poultry meat production's performance has been closely linked to growth performances and carcass characteristics of broiler birds. Supply with proper environmental conditions and nutrients is essential for the present-day commercial broiler strains targeted for the intensive production systems [1]. Any deviation from optimum conditions will lead to reduced performance in terms of profitability [2]. ...
... BWG and FCR results of the present study agreed with the findings of several previous studies [4,6,13] which showed birds at lower stocking densities at the brooding period gained more weight. The higher stocking density per unit area in intensive poultry production systems is to lower the production costs [1]. However, it may cause stress to the birds, which finally affects their productivity. ...
Article
This study aims to assess the performance and the stress response of broilers reared at different stocking densities (SD) during the brooding period. One hundred and forty-four, Cobb500, day-old broiler chicks were randomly stocked at three SDs (T1 = 40, T2 = 80, and T3 = 120 chicks/m 2) with three replicates in a completely randomised design for 1-10 days. During the brooding period, daily body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were measured. The stress response was assessed by tonic immobility duration (TI) and blood glucose level (BGL). During the growing period (11-42 days), FI and BWG were measured. On the 42 nd day, birds were slaughtered, and the carcass and meat quality traits were assessed. TI duration and BGL were significantly higher (p<0.05) in T3 (257.40 ± 6 s and 280.55 ± 3 mgdm-3 , respectively), and T1 recorded the lowest (40.86 ± 6s and 232.44 ± 3mgdm-3 , respectively) at the end of the brooding period. Significantly higher BWG (2.73 ± 0kg) and significantly lower FCR (1.35 ± 0)were observed in T1. T1 recorded a higher profit per bird (LKR 462.95 ± 13) compared to T2 (LKR 374.80 ± 13) and T3 (LKR 372.62 ± 13). Further, different stocking densities resulted in similar carcass and breast meat quality characteristics. It is concluded that a lower stocking density (40 birds/m 2) during the brooding period can lower the stress response, enhance the growth performance, and profit from broiler production.
... Poultry meat production's performance has been closely linked to growth performances and carcass characteristics of broiler birds. Supply with proper environmental conditions and nutrients is essential for the present-day commercial broiler strains targeted for the intensive production systems [1]. Any deviation from optimum conditions will lead to reduced performance in terms of profitability [2]. ...
... BWG and FCR results of the present study agreed with the findings of several previous studies [4,6,13] which showed birds at lower stocking densities at the brooding period gained more weight. The higher stocking density per unit area in intensive poultry production systems is to lower the production costs [1]. However, it may cause stress to the birds, which finally affects their productivity. ...
Article
Full-text available
This study aims to assess the performance and the stress response of broilers reared at different stocking densities (SD) during the brooding period. One hundred and forty-four, Cobb500, day-old broiler chicks were randomly stocked at three SDs (T1 = 40, T2 = 80, and T3 = 120 chicks/m 2) with three replicates in a completely randomised design for 1-10 days. During the brooding period, daily body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were measured. The stress response was assessed by tonic immobility duration (TI) and blood glucose level (BGL). During the growing period (11-42 days), FI and BWG were measured. On the 42 nd day, birds were slaughtered, and the carcass and meat quality traits were assessed. TI duration and BGL were significantly higher (p<0.05) in T3 (257.40 ± 6 s and 280.55 ± 3 mgdm-3 , respectively), and T1 recorded the lowest (40.86 ± 6s and 232.44 ± 3mgdm-3 , respectively) at the end of the brooding period. Significantly higher BWG (2.73 ± 0kg) and significantly lower FCR (1.35 ± 0)were observed in T1. T1 recorded a higher profit per bird (LKR 462.95 ± 13) compared to T2 (LKR 374.80 ± 13) and T3 (LKR 372.62 ± 13). Further, different stocking densities resulted in similar carcass and breast meat quality characteristics. It is concluded that a lower stocking density (40 birds/m 2) during the brooding period can lower the stress response, enhance the growth performance, and profit from broiler production.
... Erdem, & Őztűrk, 2008;Skomorucha Muchacka, Sosnowka-Czajka, & Herbut, 2009). Penelitian terdahulu hanya membahas pengaruh satu faktor terhadap mortalitas dan bobot badan ayam, maka dari itu tujuan dari penelitian ini adalah untuk mengetahui pengaruh tingkat kepadatan dan strain ayam broiler serta interaksi keduanya, sebagai wujud interaksi antara genetik dan lingkungan terhadap mortalitas dan bobot badan. ...
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The aim of this study was to analyze the effects of strain, density and their interaction on mortality and body weight of broiler chicken raised in the closed houses. The data was obtained from 60 broiler farms in the Central Java province. Three strains were Cobb, CP 707, and Loghman. The density level was classified into three groups: £10, >10 to <15, and ³ 15 birds/m2. Parameters observed were mortality and body weight in the first week to the fifth week (M1, M2, M3, M4, and M5) and (BB1, BB2, BB3, BB4 dan BB5), respectively. Test of significance effect for strain and density was performed using Mixed procedure of Statistical Analysis System (SAS) University Edition V.6p.2. software. The results showed that density was significant (P<0,01) on the first week (M1), their interaction was (P<0,01) on M1 and (P<0,05) on the fourth week (M4), but not significant on body weight. The conclusion from this study there was an interaction between genetic and environment on mortality one week after chick in and nearly harvesting.
... They possessed the best carcass characteristics when compared with high stocking density. Our results were confirmed with others who mentioned that increasing stocking density affects the carcass traits and reduced carcass quality (Skomorucha et al., 2009;Sekeroglu et al., 2011) a lower breast fillet (Castellini et al., 2002;Dozier et al., 2006;Abo Ghanima et al., 2020), whole breast yield (Feddes et al., 2002;Skrbi c et al., 2011;Abo Ghanima et al., 2020), and thigh (Abo Ghanima et al., 2020). Moreover, carcass traits of unsexed Arbor Acres broilers revealed that moderate stocking density (15 bird/ m 2 ) had the highest dressing weight and higher dressing percentage (75−77%) when compared with other groups (12 bird/m 2 and 20 bird/ m 2 ) but the difference was not significant (Abo Alqassem et al., 2018). ...
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The aim of the current study to investigate the potential impact of different stocking densities on growth performance, carcass traits, indicators of biochemical and oxidative stress and meat quality of Arbor Acres and Ross-308 broiler breeds to recommend the better stocking density with low production cost simultaneously with high quality. A total of 312 one-day old of each Arbor Acres broiler and Ross-308 were randomly classified into 3 experimental groups with different stocking density, each of 6 replicates. The first group (SD1) was 14 birds/m² (28kg/m²), while the second group (SD2) was 18 birds/m² (36kg/m²) and the third group (SD3) was 20 birds/m² (40kg/m²). The growth performance, carcass traits, meat quality hematological and biochemical parameters were measured. SD3 group possessed the lowest body weight. Alanine transaminase in Arbor Acres was 15 and 14% higher in SD3 when compared with SD1 and SD2, respectively. While, was 21 and 20% of Ross-308, respectively. SD3 revealed the highest values of cholesterol, TG, MDA and LDL of both breeds when compared with SD1 and SD2, with the lowest levels of HDL, GPX and IGG. Birds of SD3 was the nastiest carcass weight 873 (p=0.000) and 1411.60g (p=0.000); dressing percentage 63.07% (p=0.000) and 75.83% (p=0.000); breast weight 513.10g (p=0.000) and 885.50g (p=0.000); thigh weight 359.90g (p=0.000) and 526.08g (p=0.000) when compared with SD1 and SD2 of Arbor Acres and Ross-308, respectively. The dressing % of SD1 and SD2 was approximately 19% better than that of SD3 of Arbor Acres, while it was 4% of Ross-308. The cooking loss and drip loss of breast and thigh muscles were higher in SD3 of both breeds. Moreover, SD3 possessed the highest bacterial count. In conclusion birds reared in medium stocking density revealed better performance and welfare than high density but similar to low density. Therefore, from the economic point, medium density was the best.
... Several factors including the class and age of the bird, stocking density, litter processing, and thickness all affect the suitability of a material as bedding substrate. Higher stocking densities reduce litter quality and bird welfare (25,95) and bird performance (96,97) due to higher excreta output and rapid deterioration of the bedding material. Shao et al. (98) also observed an improved welfare and production of broiler chickens with increasing thickness of SD-based beddings from 4 to 16 cm. ...
Article
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The increasing demand of wood shavings (WS) and sawdust (SD) by other industries and growing concerns of potential chemical contaminants from wood products have amplified research interest in alternative bedding materials for commercial poultry. Several alternative materials—corn cob (CC), straws (ST) and hays (HA), sand (SA), shredded papers (SP), rice hulls (RH), peanut hulls (PH), and gypsum (CaSO 4. 2H 2 O 2 )—can replace conventional ones in poultry houses, depending on availability, cost, and ability to absorb and adsorb moisture and provide the birds enough room to exhibit their natural behaviors. Alternative materials hold a brighter future as bedding materials, but more studies about their physicochemical properties and litter management practices for optimum poultry welfare are recommended.
... The acoustic analysis has been performed in a Mediterranean farm of the BonArea Agrupa corporation (BonArea Agrupa www.bonarea-agrupa.com (accessed on 15 September 2020)) of approximately 42,000 commercial chicken farming of Ross 308 [13]. The characteristics of this farm provide a suitable environment for this study, because the automation reduces the human factor in farm management, and therefore, the man-made noise. ...
Article
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The poultry meat industry is one of the most efficient biological systems to transform cereal protein into high quality protein for human consumption at a low cost. However, to supply the increasing demand of white meat, intensive production is required whiche generates stress for the animals, which can be a major source of welfare problems. In this study, a comparative acoustic analysis of two entire production cycles of an intensive broiler Ross 308 poultry farm in the Mediterranean area has been performed. The following step to consolidate the analysis is to stablise a clear comparison among the performance of the indicators (Leq, Leq variation, Peak Frequency (PF) and PF variation) in the conditions of two different recording campaigns corresponding to summer and winter entire production cycles. The acoustic maps of PF, Leq and the related variations should be validated in an inter-campaign comparison, which may also arise the possibility of changes due to the season of the year.
... Data on feed consumption during the study show that as the stocking density increased, feed consumption decreased, and the difference between the groups was statistically significant (P < 0.01). This situation is compatible with the work on broilers by Alçiçek et al. [23], Ravindran et al. [24], and Skomorucha et al. [25]. However, with a decrease in stocking density, feed consumption increased but without statistical significance [26]. ...
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This study was conducted to observe the effects of thyme plant (Thymbra spicata L.var. spicata) volatile oil on quails and intestinal microbiota in high stocking density. For this purpose, 300 7-day-old Japanese quails (Coturnix coturnix Japonica) were used in the study. The quails were selected on the basis of body weight and divided into 6 groups, each consisting of 5 replications that contained 50 quail chicks according to the following experimental design: positive control group (NSD - CONT), with normal stocking density and no additive; negative control group (HSD - CONT), with high stocking density (HSD) and no additive; group HSD - ANT, with HSD and 10 mg/kg of avilamycin additive, and other groups named HSD - T1, T2, and T3, with HSD and 200, 400, and 600 mg/kg of volatile oil additive respectively. In the study, a stocking density of 160 cm2/quail was chosen, while the high stocking density (HSD) was 90 cm2/quail. A statistically significant difference was found in terms of improvements in feed intake and feed conversion ratio (P < 0.01), and the highest total bacteria count (cfu/g) was observed in HSD - CONT group (P < 0.01). The addition of zahter-thyme volatile oil in the diet of quails kept in high stocking density provided improvements at various levels with regard to intestinal microbiota and animal performance. It was observed that the inclusion of zahter-thyme volatile oil, in particular at 600 mg per kg level, reduced the detrimental effects of stress generated by high stocking density.
Article
This investigation was aimed to inspect if there is an influence of various stocking density on growth, carcass parameters, blood indices and meat traits of Muscovy and Mallard ducks. 126 one-day old of each Muscovy and Mallard ducks were randomly allocated into three experimental groups with different stocking density. Group one (SD1) was 5ducks/m², while group two (SD2) was 7ducks/m² and group three (SD3) was 9ducks/m². The growth, carcass parameters, meat quality, blood indices were calculated. Body weight of SD1 was 18 and 4.5% heavier than SD2, while, it was 29.5and12% heavier than SD3 of Muscovy and Mallard duck breeds, respectively. SD3 possessed the highest levels of, H/L, ALT, AST, LDL, VLDL and MDA with the lowest levels of lymphocyte, SOD,GSH, GPX, C3, total antioxidant capacity and IGG of both ducks' breeds. The carcass weight decreased by 40 and 15% from SD1 to SD3 in Muscovy and mallard ducks, respectively. The dressing % was highest at SD1(84and83%) when compared with SD3(71and80%) of Muscovy and Mallard ducks, respectively. Cooking loss was 20and16% greater in group three when compared with group one in Muscovy and Mallard ducks, respectively. In conclusion ducks raised in low SD possessed the best performance with better welfare.
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The currently used poultry farming methods, which aim to maximise economic profit, are based on ever new technological solutions that improve flock management and increase bird performance. However, they do not always meet the natural needs of birds. Every housing method and technological solution currently in use is faced with some issues, such as social stress, adverse temperature/humidity conditions, risk of zoonoses, and behavioural pathologies, which determine poultry performance and welfare. Disregard for animal welfare involves not only ethical but also practical aspects, because well-being and housing comfort translate into better weight gains, health and productivity of the birds. The studies reported here suggest that every production system, despite the many welfare-improving aspects, causes numerous behavioural, productivity and health abnormalities in laying hens. Therefore, further research is needed to identify various risk factors for the purpose of improving housing systems and increasing the welfare of hens.
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The aim of the study was to determine the duration of tonic immobility (TI) and some biochemical parameters of blood in broiler chickens according to stocking density and management system. Chicks were assigned to 6 groups. Groups I, II and III were kept in a battery of cages at a stocking density of 13, 15 and 17 birds/m(2), respectively, and groups 4, 5 and 6 were reared in compartments on litter at a stocking density of 13, 15 and 17 birds/m(2), respectively. Chickens were fed ad libitum standard diets. At 28, 35 and 42 weeks of rearing, the duration of tonic immobility was measured in 7 birds randomly chosen from each group, and their blood was sampled to determine the haematocrit value and the concentration of haemoglobin, glucose and immunoglobulins. Comparison of the cage and litter systems showed a tendency towards a longer duration of TI in birds reared in cage batteries. Analysis of TI duration according to stocking density within the system showed a significant difference at 28 days of the experiment in the cage system only between chickens from a group housed at a stocking density of 17 birds/m(2) and the other groups. The level of biochemical indicators of blood showed differences within management systems and at the same stocking density, as demonstrated by the statistically significant differences between the groups. It is concluded that both management system and stocking density affect the physiological response of broiler chickens by disturbing body homeostasis, which may adversely affect bird productivity and health, with management system having a more pronounced effect than stocking density on the physiological parameters of broilers.
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The behaviour, angulations of proximal tibiae and walking ability of three fast growing broiler breeds (Ross, Lohmann, Hubbard) and one with a low growth rate (ISA S 657;,,Label Rouge") were investigated in deep litter compartments over a 5 week fattening period. Great differences in behaviour; angulations of proximal tibiae and walking ability between the light and heavy broiler strains were observed. The duration of locomotor activity, standing, scratching and walking ability was higher and duration of lying and angulations of proximal tibiae was lower in broilers with a low growth rate. The behaviour and the angulations of proximal tibiae of fast growing broilers showed minor differences. Differences of walking ability between the fast growing broiler strains can not be explained with growth rate or behaviour. The locomotor- and scratching activity of fast growing broilers decreased rapidly in the third week. Genetic factors or leg weakness may be the cause of differences in behaviour.
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The aim of this experiment was to determine the effect of the litter barn and free-range management systems on the productivity and behaviour of broiler chickens from three different commercial lines. Broiler chickens were assigned to the following groups: Group I — chickens of the Cobb 500 commercial line, kept on litter without access to free range; Group II — chickens of the Hubbard commercial line, kept on litter without access to free range; Group III — chickens of the Ross 308 commercial line, kept on litter without access to free range; Group IV — chickens of the Cobb 500 commercial line, kept on litter with access to free range; Group V — chickens of the Hubbard commercial line, kept on litter with access to free range; Group VI — chickens of the Ross 308 commercial line, kept on litter with access to free range. It is concluded that the best fattening results were obtained by broilers from the Cobb 500 commercial line and the poorest by Ross 308 broilers, regardless of the rearing system. This may indicate that genetic factors in addition to rearing conditions have a considerable effect on production results. Broiler chickens with access to free range showed their natural patterns of behaviour much more frequently, while birds kept in the barn system had limited scope for expressing these patterns. Hence it is concluded that the management system with access to free range is characterized by improved bird welfare compared to the barn system, as manifested in broiler behaviour. When planning to rear broiler chickens in the system with access to free range, commercial lines giving good fattening results in the free range system should be chosen, as the present experiment shows that the material from some companies may achieve poor production parameters in this management system.
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This study was undertaken to investigate the effects of lighting and stocking density on performance, carcass characteristics and some stress parameters (H-L ratio, serum glucose, cholesterol and triglyceride levels, tonic immobility test (TI), antibody production, relative asymmetry (RA) and external appearances). Four hundred and seventy day-old male broiler chicks (Ross 308) were obtained from a commercial hatchery. The chicks were randomly distributed into two light proof controlled rooms. In one room the lighting period remained at continuous lighting (24 L: 0D) during the whole experiment, while in the other room the photoperiod was 16 h light and 8 h dark per day. Each lighting group was divided into two stocking density groups (11.9 b/m2 (average 29.9 kg of BW/m2) and 17.5 b/m2 (average 40.7 kg of BW/m2)) with 5 replications per group. Lighting program did not influence slaughter weight, body weight gain, feed consumption, feed to gain ratio, carcass characteristics, percentage of abdominal fat, heart, gizzard, liver, spleen and bursa of Fabricius, RA of metatarsus length, RA of tarsometatarsus length and thickness, mean RA, claw length, foot health, serum glucose, cholesterol and triglyceride levels anti-SRBC and anti NDV titers. TI duration (p < 0.001), feather condition (p < 0.001) and H-L ratio (p < 0.05) of broilers were significantly different in lighting groups. TI duration was 255 and 431 s, feather condition was 16.3 and 14.5 and H-L ratio was 1.0 and 1.2 in broilers exposed to 16L:8D lighting program and 24L:0D lighting program, respectively. Stocking density influenced final body weight (p < 0.001), body weight gain (p < 0.001), feed consumption (p < 0.05) and feed to gain ratio (p < 0.05). Final body weight was 2515 and 2326 g, feed consumption was 3829 and 3662 g and feed to gain ratio was found 1.55 and 1.61 g/g in broilers reared at 11.9 b/m2 and 17.5 b/m2, respectively. Feather condition (p < 0.001) and foot health (p < 0.01) were significantly different in stocking density groups. Feather condition was 16.5 and 14.3 and foot health was 3.6 and 3.0 in broilers reared at 11.9 and 17.5 b/m2, respectively. Percentage of heart (p < 0.05), TI duration (p < 0.001), H-L ratio (p < 0.001), serum glucose (p < 0.001) and serum cholesterol levels (p < 0.05) were statistically higher in broilers reared at 17.5 b/m2 than in broilers reared at 11.9 b/m2. In conclusion darkness period and stocking density play an important role in modern broiler rearing.
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The purpose of the present study was to evaluate the effects of intermingling chicks and bird density on stressfulness and fearfulness of chickens. There were two different experiments. The first experiment measured heterophil to lymphocyte ratio and tonic immobility duration in 20-wk-old birds (n = 106) of two Spanish breeds (Black Castellana and Quail Castellana) which had been reared intermingled or separately. There was significant treatment by breed interaction (P < 0.01) for the heterophil to lymphocyte ratio, the ratio being significantly higher (heterophilia and lymphopenia) in the separate than in the intermingled Black Castellana, whereas treatment had no significant effect on the stress level of birds from the Quail Castellana breed. There was also significant qualitative treatment by breed interaction for the tonic immobility duration, intermingling reducing significantly fearfulness of Quail Castellana whereas had no influence on the fear response of Black Castellana.. The second experiment measured heterophil to lymphocyte ratio and tonic immobility duration in 20-wk-old birds (n = 216) of four Spanish breeds (Black Castellana, Red Villafranquina, Barred Red Vasca, and Buff Prat) which had been reared with five different bird densities: 4, 8, 12, 16, and 20 birds/m 2, respectively. There was significant difference among bird densities for the heterophil to lymphocyte ratio. The ratio increased significantly with bird density, mean value in the 20 birds/m2 density being significantly higher (heterophilia and lymphopenia) than those in the 4 and 8 birds/m2 densities. There was no significant effect of bird density on the tonic immobility duration.
Article
The aim of the study was to determine the effect of injecting linseed oil into the yolk sac of chicks on the physiological reaction of birds exposed to elevated air temperature. Day-old chicks were assigned to 4 groups: 1 - chickens reared under standard thermal conditions; 2 - on the first day of rearing, 0.25 ml of linseed oil was injected into the yolk sac of chicks, which were reared under standard thermal conditions; 3 - at 4 weeks of rearing, chickens were exposed to a 5-day increase in air temperature to 30°C; 4 - on the first day of rearing, 0.25 ml of linseed oil was injected into the yolk sac of chickens, and at 4 weeks of rearing chickens were exposed to a 5- day increase in air temperature to 30°C. Bird productivity was recorded throughout the experiment. Before, during, and after the period when experimental factors were applied, as well as on the last day of rearing, the rectal temperature and radiation temperature of feathered and unfeathered parts of the skin were measured in 10 birds from each group. The plasma levels of thyroid hormones (T3 and T4) and corticosterone were determined before and after the experimental factor was applied and on the last day of the experiment in 10 randomly chosen birds from each group. The results were analysed using two-factorial analysis of variance. It is concluded that the use of a thermal experimental factor resulted in a stress reaction, as confirmed by the elevated corticosterone level and the reduced T3 level in blood. However, the injection of linseed oil into the yolk sacs of day-old broiler chicks increased their resistance to thermal stress, as evidenced by their ability to maintain constant rectal temperature.