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Vocalizations and Behavior of Two Commercial Stocks of Chickens
Vocalizations and Behavior of Two Commercial Stocks of Chickens N. D. STONE, P. B. SIEGEL, C. S. ADKISSON, and W. B. GROSS
Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (Received for publication August 9, 1983)
INTRODUCTION The welfare of farm animals continues to be a concern among producers and consumers, and much of the attention is directed toward the husbandry of commercial egg layers. Criteria used to evaluate the well-being of animals include the phenotypic expression of behavioral, physiological, and production traits. None, however, is without its limitations (Dawkins, 1980; Duncan, 1981; Baxter, 1983; Hill, 1983). Ultimately, an index involving various criteria may be the most satisfactory method of measuring an animal's well-being. Because most types of vocalizations by the domestic chicken occur under a broad range of conditions, they may represent expressions of more global behavioral sets or moods, as well as being signals (Phillips, 1983). Folsch (1980) noted that chickens maintained under three different husbandry systems emitted different frequencies of "friendly" and dominant calls. Additional studies are needed to ascertain the validity of using vocalizations as an assay of the well-being of chickens. The objective of this experiment was to compare vocalizations of two commercial strains of White Leghorn chickens with their behavior in multiple-bird battery cages. MATERIALS AND METHODS The chickens used in this experiment were females from two commercial White Leghorn stocks (A and B) maintained in three-tier commercial battery cages (60.95 X 45.72 X 38.10 cm) in the same house, which contained more than 50,000 pullets. At housing, 9 pullets were placed in each cage.
Vocalizations were recorded with a Uher 4000 Report-IC tape recorder at a tape speed of 19 cm/sec. Recordings were made in the aisle between rows of battery cages after the birds were allowed a minimum of 5 min to adjust to the observer's presence. Sonagrams were prepared with a Kay Elemetrics Sonagraph 7029A using the frequency range of 40 to 4000 Hz and the wide (300 Hz) band filter. Behavioral data were obtained from 36 cages of Stock A and 30 cages of Stock B pullets. Three cages were observed simultaneously for 10 min, and the frequencies of pecks, threats, steps, and pushes were recorded. Observations were made from 1100 to 1400 hr with the ordering of stocks observed being on an alternate basis. A peck was denoted as the forward motion of the attacker's head with the beak striking the victim; a threat was identical to this, except that contact was not made. One bird placing its foot on the other was scored a step, and a push was recorded when one chicken supplanted another by forcibly moving it with its body. The numerical data for each cage were converted to a per bird per 10-min observation period basis and transformed to square roots prior to analysis of variance using a completely randomized design. RESULTS AND DISCUSSION Means and standard errors of number of birds per cage when data were obtained at 35 weeks of age were 8.0 ± .2 and 8.4 ± .2 for Stocks A and B, respectively. The pullets of both stocks spent a large percentage of the ob-
616
Downloaded from http://ps.oxfordjournals.org/ at Iowa State University on November 2, 2014
ABSTRACT Vocalization and behavior comparisons were made between two commercial egglaying stocks maintained under high intensity, battery-cage housing. Data obtained at approximately 3 5 weeks of age from both stocks in the same house showed significantly more pushes and steps in Stock B than in Stock A flocks. Also, the frequency range of vocalizations emitted was greater for Stock B than for Stock A pullets. This difference was attributed to an increased number of disturbance calls and shriek-like sounds called "baaks". (Key words: chickens, vocalization, behavior) 1984 Poultry Science 63:616-619
VOCALIZATION AND BEHAVIOR IN HENS TABLE 1. Means1 and standard errors for number of pushes and steps per bird in battery cages Stock
Pushes*
Steps*
A B
.24 .42
.33 ± .06 .72 ± .11
1
.04 .07
Number per bird per 10-min period.
*Means were different (P<,05). **Means were different (P<.01).
either stock. T h e low level of such behavior is not surprising for b a t t e r y cage e n v i r o n m e n t s (Craig, 1982). Stock B chickens exhibited significantly m o r e pushes and steps t h a n those from Stock A (Table 1). Most pushes occurred as a u n i q u e episode, whereas steps usually occurred during brief b o u t s . When a chicken was stepped o n , escape behavior was observed, aijd there was disruption in t h e cage a c c o m p a n i e d by an increase in vocalizations. Birds in neighboring cages did n o t appear to be disturbed b v these episodes. T h e stock differences and lack of influences on neighboring cages are consistent with t h e observations of Hansen ( 1 9 7 6 ) and Craig et al. ( 1 9 8 3 ) regarding tendencies for t h e d e v e l o p m e n t of nervousness and hysteria in b a t t e r y cages.
iz : 1
•' a
\
"f
- #iif^
I
0
ttiKH&NHNHNIll&b-
T SECONDS
FIG. 1. Sonagrams of disturbance call (a), baak (b), and moan (c).
Downloaded from http://ps.oxfordjournals.org/ at Iowa State University on November 2, 2014
servation t i m e at t h e feed trough. Only t w o pecks were observed for Stock B, and n o n e was n o t e d for Stock A. No t h r e a t s were observed in
617
618
STONE ET AL. mental (base) frequency of disturbance calls is approximately 700 Hz with harmonics as high as 4000 Hz. The "baak" is named after its shriek-like sound and is a sustained note frequently emitted after increasing disturbance calls. Its fundamental frequency is about 600 Hz with harmonic overtones present at 750 Hz intervals up to and above 8000 Hz. Moans were frequently heard. Previous experiments conducted in our laboratory showed that moans were emitted when the chickens appeared docile and undisturbed. They consisted of fairly long, low, soft sounds whose acoustic properties closely resemble the ku and
i
1 .jjjjjjjjj.
a I
&>/;.;•
§ %
f b . • > . .
5
.
••;
Wlliwp
T
%0yf7 O" U I V L ' O FIG. 2. Sonagrams of composite flock vocalizations for Stock A (a) and Stock B (b).
Downloaded from http://ps.oxfordjournals.org/ at Iowa State University on November 2, 2014
During a disruptive episode, two call-types were often heard whose acoustic properties were similar to the ground predator warning call (Collias and Joos, 195 3) and the warning call-type 1 and 2 (Konishi, 1963). In Figure 1, the short repetitive notes a) denote the disturbance call and the longer note b) denotes a "baak". These calls, although heard separately, were often emitted together. Sonagraphic analyses show that the disturbance call consists of repetitive notes each .02 to .05 seconds in duration uttered at a fairly constant rhythm. The rate and delivery of these notes increased as the bird became more disturbed. The funda-
VOCALIZATION AND BEHAVIOR IN HENS
T h e flightier behavior e x h i b i t e d b y t h e chickens in S t o c k B, as illustrated b y increased frequencies of steps and pushes, was characterized b y their vocalizations. This p o i n t is consistent with t h e observations of Baeumer ( 1 9 6 2 ) , w h o listed a call (Beruhrungsabwehr) t h a t is e m i t t e d w h e n a bird gets p u s h e d . Alt h o u g h described as a rough u n d u l a t i n g sound, which may be quiet or m o d e r a t e l y strong, neither sonagrams nor quantitative data were presented in t h a t paper. Hansen ( 1 9 7 6 ) discussed pain as a causative factor in t h e transition from nervousness to hysteria. We t h u s
hypothesize t h a t there is a strong association between higher levels of stepping and pushing in Stock B a n d t h e quality of their vocalizations in comparison with those of Stock A. ACKNOWLEDGMENT This research was s u p p o r t e d , in part, b y cooperative agreement # 5 8 - 5 1 9 B - l - 1 1 2 3 w i t h USDA-ARS.
REFERENCES Baeumer, E., 1962. Lebensart des Haushuhns, dritter Teil-uber seine Laute und allgemelne Erganzungen. Z. Tierpsychol. 9:394-416. Baxter, M. R., 1983. Ethology in environmental design for animal production. Appl. Anim. Ethol. 9: 207-220. Collias, N. E., and M. Joos, 1953. The spectrographic analysis of sound signals of the domestic fowl. Behaviour 5:176-188. Craig, J. V., 1982. Behavioral and genetic adaptation of laying hens to high density environments. BioScience 32:33-37. Craig, J. V., T. P. Craig, and A. D. Dayton, 1983. Fearful behavior of caged hens of two genetic stocks. Appl. Anim. Ethol. 10:263-273. Dawkins, M. S., 1980. Animal suffering: The Science of Animal Welfare. Chapman and Hall, New York, NY. Duncan, I.J.H., 1981. Animal rights—Animal welfare; A scientist's assessment. Poultry Sci. 60:489— 499. Folsch, D. W., 1980. Essential behavioral needs. Pages 121—132 in The Laying Hen and Its Environment. R. Moss, ed. Martinus Nijhoff Publ., Boston, MA. Hansen, R. S., 1976. Nervousness and hysteria of mature female chickens. Poultry Sci. 55:531— 543. Hill, J. A., 1983. Indicators of stress in poultry. World's Poultry Sci. J. 3 9 : 2 4 - 3 1 . Konishi, M., 1963. The role of auditory feedback in the vocal behavior of the domestic fowl. Z. Tierpsychol. 20:349-367. Phillips, R. E., 1983. Vocal behavior and its neural control in the domestic fowl. Pages 213—226 in The Brain and Behavior of the Fowl. T. Ookawa, ed. Jpn. Sci. Soc. Press, Tokyo.
Downloaded from http://ps.oxfordjournals.org/ at Iowa State University on November 2, 2014
laying call described b y Konishi ( 1 9 6 3 ) . As seen in Figure l c , frequencies with t h e greatest amp l i t u d e were b e t w e e n 1 0 0 0 and 1 4 0 0 Hz. T h e range of this vocalization rarely exceeded 2 0 0 0 Hz. A l t h o u g h t h e sounds e m i t t e d b y pullets from b o t h stocks were l o u d and had a noisy, din-like quality, those from S t o c k B had a higher overall intensity, which gave an a u d i t o r y impression of their being "flightier". Vocalizations from b o t h stocks lacked high frequencies and h a r m o n i c structures (Figure 2). Stock A (a) had a c o n c e n t r a t e d b a n d of frequencies from 9 5 0 t o 1 2 5 0 Hz, whereas S t o c k B (b) had a considerably wider range of frequencies ( 5 0 0 t o 2 4 0 0 Hz). Stock A pullets e m i t t e d mainly m o a n s with acoustic parameters similar t o those f o u n d in t h e g r o u p sonagram for this stock. A l t h o u g h m o a n s were also c o m m o n for Stock B, there were increased occurrences of individual vocalizations such as d i s t u r b a n c e calls and " b a a k s " . T h e difference b e t w e e n t h e stocks in t h e o c c u r r e n c e of these vocalizations m a y be indicative of t h e increased incidence of pushing and stepping observed a m o n g birds from Stock B. T h e increased h a r m o n i c c o n t e n t of these vocalizations ( > 2 0 0 0 Hz) p r o b a b l y c o n t r i b u t e d t o the differences in acoustic properties bet w e e n t h e stocks.
619
Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (Received for publication August 9, 1983)
INTRODUCTION The welfare of farm animals continues to be a concern among producers and consumers, and much of the attention is directed toward the husbandry of commercial egg layers. Criteria used to evaluate the well-being of animals include the phenotypic expression of behavioral, physiological, and production traits. None, however, is without its limitations (Dawkins, 1980; Duncan, 1981; Baxter, 1983; Hill, 1983). Ultimately, an index involving various criteria may be the most satisfactory method of measuring an animal's well-being. Because most types of vocalizations by the domestic chicken occur under a broad range of conditions, they may represent expressions of more global behavioral sets or moods, as well as being signals (Phillips, 1983). Folsch (1980) noted that chickens maintained under three different husbandry systems emitted different frequencies of "friendly" and dominant calls. Additional studies are needed to ascertain the validity of using vocalizations as an assay of the well-being of chickens. The objective of this experiment was to compare vocalizations of two commercial strains of White Leghorn chickens with their behavior in multiple-bird battery cages. MATERIALS AND METHODS The chickens used in this experiment were females from two commercial White Leghorn stocks (A and B) maintained in three-tier commercial battery cages (60.95 X 45.72 X 38.10 cm) in the same house, which contained more than 50,000 pullets. At housing, 9 pullets were placed in each cage.
Vocalizations were recorded with a Uher 4000 Report-IC tape recorder at a tape speed of 19 cm/sec. Recordings were made in the aisle between rows of battery cages after the birds were allowed a minimum of 5 min to adjust to the observer's presence. Sonagrams were prepared with a Kay Elemetrics Sonagraph 7029A using the frequency range of 40 to 4000 Hz and the wide (300 Hz) band filter. Behavioral data were obtained from 36 cages of Stock A and 30 cages of Stock B pullets. Three cages were observed simultaneously for 10 min, and the frequencies of pecks, threats, steps, and pushes were recorded. Observations were made from 1100 to 1400 hr with the ordering of stocks observed being on an alternate basis. A peck was denoted as the forward motion of the attacker's head with the beak striking the victim; a threat was identical to this, except that contact was not made. One bird placing its foot on the other was scored a step, and a push was recorded when one chicken supplanted another by forcibly moving it with its body. The numerical data for each cage were converted to a per bird per 10-min observation period basis and transformed to square roots prior to analysis of variance using a completely randomized design. RESULTS AND DISCUSSION Means and standard errors of number of birds per cage when data were obtained at 35 weeks of age were 8.0 ± .2 and 8.4 ± .2 for Stocks A and B, respectively. The pullets of both stocks spent a large percentage of the ob-
616
Downloaded from http://ps.oxfordjournals.org/ at Iowa State University on November 2, 2014
ABSTRACT Vocalization and behavior comparisons were made between two commercial egglaying stocks maintained under high intensity, battery-cage housing. Data obtained at approximately 3 5 weeks of age from both stocks in the same house showed significantly more pushes and steps in Stock B than in Stock A flocks. Also, the frequency range of vocalizations emitted was greater for Stock B than for Stock A pullets. This difference was attributed to an increased number of disturbance calls and shriek-like sounds called "baaks". (Key words: chickens, vocalization, behavior) 1984 Poultry Science 63:616-619
VOCALIZATION AND BEHAVIOR IN HENS TABLE 1. Means1 and standard errors for number of pushes and steps per bird in battery cages Stock
Pushes*
Steps*
A B
.24 .42
.33 ± .06 .72 ± .11
1
.04 .07
Number per bird per 10-min period.
*Means were different (P<,05). **Means were different (P<.01).
either stock. T h e low level of such behavior is not surprising for b a t t e r y cage e n v i r o n m e n t s (Craig, 1982). Stock B chickens exhibited significantly m o r e pushes and steps t h a n those from Stock A (Table 1). Most pushes occurred as a u n i q u e episode, whereas steps usually occurred during brief b o u t s . When a chicken was stepped o n , escape behavior was observed, aijd there was disruption in t h e cage a c c o m p a n i e d by an increase in vocalizations. Birds in neighboring cages did n o t appear to be disturbed b v these episodes. T h e stock differences and lack of influences on neighboring cages are consistent with t h e observations of Hansen ( 1 9 7 6 ) and Craig et al. ( 1 9 8 3 ) regarding tendencies for t h e d e v e l o p m e n t of nervousness and hysteria in b a t t e r y cages.
iz : 1
•' a
\
"f
- #iif^
I
0
ttiKH&NHNHNIll&b-
T SECONDS
FIG. 1. Sonagrams of disturbance call (a), baak (b), and moan (c).
Downloaded from http://ps.oxfordjournals.org/ at Iowa State University on November 2, 2014
servation t i m e at t h e feed trough. Only t w o pecks were observed for Stock B, and n o n e was n o t e d for Stock A. No t h r e a t s were observed in
617
618
STONE ET AL. mental (base) frequency of disturbance calls is approximately 700 Hz with harmonics as high as 4000 Hz. The "baak" is named after its shriek-like sound and is a sustained note frequently emitted after increasing disturbance calls. Its fundamental frequency is about 600 Hz with harmonic overtones present at 750 Hz intervals up to and above 8000 Hz. Moans were frequently heard. Previous experiments conducted in our laboratory showed that moans were emitted when the chickens appeared docile and undisturbed. They consisted of fairly long, low, soft sounds whose acoustic properties closely resemble the ku and
i
1 .jjjjjjjjj.
a I
&>/;.;•
§ %
f b . • > . .
5
.
••;
Wlliwp
T
%0yf7 O" U I V L ' O FIG. 2. Sonagrams of composite flock vocalizations for Stock A (a) and Stock B (b).
Downloaded from http://ps.oxfordjournals.org/ at Iowa State University on November 2, 2014
During a disruptive episode, two call-types were often heard whose acoustic properties were similar to the ground predator warning call (Collias and Joos, 195 3) and the warning call-type 1 and 2 (Konishi, 1963). In Figure 1, the short repetitive notes a) denote the disturbance call and the longer note b) denotes a "baak". These calls, although heard separately, were often emitted together. Sonagraphic analyses show that the disturbance call consists of repetitive notes each .02 to .05 seconds in duration uttered at a fairly constant rhythm. The rate and delivery of these notes increased as the bird became more disturbed. The funda-
VOCALIZATION AND BEHAVIOR IN HENS
T h e flightier behavior e x h i b i t e d b y t h e chickens in S t o c k B, as illustrated b y increased frequencies of steps and pushes, was characterized b y their vocalizations. This p o i n t is consistent with t h e observations of Baeumer ( 1 9 6 2 ) , w h o listed a call (Beruhrungsabwehr) t h a t is e m i t t e d w h e n a bird gets p u s h e d . Alt h o u g h described as a rough u n d u l a t i n g sound, which may be quiet or m o d e r a t e l y strong, neither sonagrams nor quantitative data were presented in t h a t paper. Hansen ( 1 9 7 6 ) discussed pain as a causative factor in t h e transition from nervousness to hysteria. We t h u s
hypothesize t h a t there is a strong association between higher levels of stepping and pushing in Stock B a n d t h e quality of their vocalizations in comparison with those of Stock A. ACKNOWLEDGMENT This research was s u p p o r t e d , in part, b y cooperative agreement # 5 8 - 5 1 9 B - l - 1 1 2 3 w i t h USDA-ARS.
REFERENCES Baeumer, E., 1962. Lebensart des Haushuhns, dritter Teil-uber seine Laute und allgemelne Erganzungen. Z. Tierpsychol. 9:394-416. Baxter, M. R., 1983. Ethology in environmental design for animal production. Appl. Anim. Ethol. 9: 207-220. Collias, N. E., and M. Joos, 1953. The spectrographic analysis of sound signals of the domestic fowl. Behaviour 5:176-188. Craig, J. V., 1982. Behavioral and genetic adaptation of laying hens to high density environments. BioScience 32:33-37. Craig, J. V., T. P. Craig, and A. D. Dayton, 1983. Fearful behavior of caged hens of two genetic stocks. Appl. Anim. Ethol. 10:263-273. Dawkins, M. S., 1980. Animal suffering: The Science of Animal Welfare. Chapman and Hall, New York, NY. Duncan, I.J.H., 1981. Animal rights—Animal welfare; A scientist's assessment. Poultry Sci. 60:489— 499. Folsch, D. W., 1980. Essential behavioral needs. Pages 121—132 in The Laying Hen and Its Environment. R. Moss, ed. Martinus Nijhoff Publ., Boston, MA. Hansen, R. S., 1976. Nervousness and hysteria of mature female chickens. Poultry Sci. 55:531— 543. Hill, J. A., 1983. Indicators of stress in poultry. World's Poultry Sci. J. 3 9 : 2 4 - 3 1 . Konishi, M., 1963. The role of auditory feedback in the vocal behavior of the domestic fowl. Z. Tierpsychol. 20:349-367. Phillips, R. E., 1983. Vocal behavior and its neural control in the domestic fowl. Pages 213—226 in The Brain and Behavior of the Fowl. T. Ookawa, ed. Jpn. Sci. Soc. Press, Tokyo.
Downloaded from http://ps.oxfordjournals.org/ at Iowa State University on November 2, 2014
laying call described b y Konishi ( 1 9 6 3 ) . As seen in Figure l c , frequencies with t h e greatest amp l i t u d e were b e t w e e n 1 0 0 0 and 1 4 0 0 Hz. T h e range of this vocalization rarely exceeded 2 0 0 0 Hz. A l t h o u g h t h e sounds e m i t t e d b y pullets from b o t h stocks were l o u d and had a noisy, din-like quality, those from S t o c k B had a higher overall intensity, which gave an a u d i t o r y impression of their being "flightier". Vocalizations from b o t h stocks lacked high frequencies and h a r m o n i c structures (Figure 2). Stock A (a) had a c o n c e n t r a t e d b a n d of frequencies from 9 5 0 t o 1 2 5 0 Hz, whereas S t o c k B (b) had a considerably wider range of frequencies ( 5 0 0 t o 2 4 0 0 Hz). Stock A pullets e m i t t e d mainly m o a n s with acoustic parameters similar t o those f o u n d in t h e g r o u p sonagram for this stock. A l t h o u g h m o a n s were also c o m m o n for Stock B, there were increased occurrences of individual vocalizations such as d i s t u r b a n c e calls and " b a a k s " . T h e difference b e t w e e n t h e stocks in t h e o c c u r r e n c e of these vocalizations m a y be indicative of t h e increased incidence of pushing and stepping observed a m o n g birds from Stock B. T h e increased h a r m o n i c c o n t e n t of these vocalizations ( > 2 0 0 0 Hz) p r o b a b l y c o n t r i b u t e d t o the differences in acoustic properties bet w e e n t h e stocks.
619