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Drinking behaviour of broiler chicks
Applied Animal Ethology, 11 (1983/84) 25-31 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands
DRINKING
BEHAVIOUR
OF BROILER
25
CHICKS
P.A. ROSS and J.F. HURNIK Department of Animal and Poultry Science, Nl G 2 WI (Canada)
University of Guelph, Guelph, Ontario
(Accepted for publication 29 June 1982)
ABSTRACT Ross, P.A. and Hurnik, J.F., Ethol., 11: 25-31.
1983.
Drinking behaviour of broiler chicks. Appl. Anim.
A study of drinking behaviour of individual broiler breeder chicks from hatching to 5 weeks of age was conducted. The action patterns involved in obtaining a drink as well as water consumption were described quantitatively and qualitatively. Over the experimental period, the action patterns of drinking were modified gradually. Marked changes in immersion angle, swallowing angle and distance from the waterer were evident. All birds made progressively fewer trips to the waterer to take a larger number of higher volume drinks. This information is essential for future design of improved watering equipment to better complement the natural drinking behaviour of broiler chickens.
INTRODUCTION
Water is a nutrient which plays a vital role in all aspects of body metabolism. Maintenance of adequate water consumption is, therefore, a priority function of the body’s homeostatic mechanism. For this reason, knowledge of the normal quantitative and qualitative aspects of drinking behaviour constitute important basic information for any species. Such information can then be utilized as an effective diagnostic tool allowing disruptions, indicative of pathological and psychological upset, to be detected at an early stage. Most current poultry management practices, as well as equipment and facilities used for housing birds, have been designed with only empirical knowledge of instinctive behaviour patterns of poultry. Although a few studies describe drinking movements (Rheingold and Hess, 1957; Farner, 1960; Hunt and Smith, 1967), and discuss individual water consumption (Savory, 1978), there is an obvious need for objective, precise data. The scarcity of information on drinking behaviour can be attributed largely to the lack of accurate long-term monitoring techniques in the past. Thus, the following study was conducted: (1) to describe the action patterns involved in drinking behaviour of young broiler breeders; (2) to obtain accurate information on water consumption variables.
0304-3762/83/$03.00
o
1983 Elsevier Science Publishers B.V.
26
MATERIALS
Subjects
AND METHODS
and management
Ten one-day-old broiler breeder chicks were fitted with large wingbands which were clearly visible on a video-playback screen. They were housed in a circular area (1.2 m in diameter) formed by a 45-cm high cardboard chick guard and equipped with an infrared brooder heat lamp and trough feeder. Ambient temperature was kept constant at 25°C. The birds were given continuous light at an intensity of 300 lux to permit 24-h video-recording. Starter diet (20% C.P., 2970 kcal M.E./kg) was provided ad libitum. The chicks were maintained in this manner until the end of the study at 5 weeks of age. Apparatus
The chick guard opened into an alley, bordered by calibrated, clear plexiglass walls, which led to the waterer. The width of the alley was such that only one bird could approach the waterer at a time, and was progressively increased from 7 to 14 cm as the birds grew. Similarly, the length of the alley was increased from 13 to 18 cm over the course of the study. Water for the experimental birds was provided in a calibrated, clear plastic bowl. The waterer was positioned on a Mettler electronic digital scale, and changes in water consumption were recorded to 0.1 g. The position of the scale was adjusted weekly to maintain the edge of the water bowl at the breast level of the chicks. A clock was positioned above the scale. Variables and statistics
Video-recordings of individual bird activity at the waterer were obtained for two 24-h periods each week. The video equipment consisted of a camera with a wide-angle lens and a Hitachi time-lapse video-recorder. Scaleregistered changes in the weight of the waterer due to drinking were clearly visible on the TV monitor. Observations of drinking behaviour patterns were recorded at 5day intervals, and consisted of individual measures of distance from the waterer when drinking, immersion angle, depth of break immersion while obtaining a drink and swallowing angle. Measurement of these variables was aided by calibrations on both the plexiglass alley and the water bowl. Operationally, these variables were defined as follows: Distance from the waterer was the horizontal distance from the edge of the scale to the foremost leg (the edge of the scale was in line with the edge of the waterer. Immersion angle (Fig. la) was measured from a vertical axis through the eye (vertex) to an imaginary axis projected to the tip of the beak at the point of contact with the water.
27
a
b
Fig. 1. a. Immersion
angle. b. Swallowing
angle.
Depth of beak immersion was measured from the surface of the water to the tip of the beak at maximum depth. Swallowing angle (Fig. lb) was measured from a vertical axis through the eye (vertex) to an imaginary axis projected to the tip of the beak at its highest swallowing elevation. The consumption data obtained for each bird consisted of number of approaches to the waterer per day, number of drinks per approach to the waterer, average water intake per drink, time spent at the waterer per approach and total water consumption per day.
28
Regressions over time were plotted for all consumption and description variables. Since the same birds were observed at each time-period, coefficient of determination of significance tests were not calculated due to lack of independence between observations. RESULTS
AND
DISCUSSION
The results of this study provide information on patterns of drinking behaviour of young broiler breeders. Table I and Fig. 2 illustrate the variation of the above-mentioned drinking parameters over time and the action patterns involved in obtaining a drink. Neonatal chicks oriented to the waterer, approached to a distance of 5.7 cm, then stopped and lowered their heads to an angle of 161.6” from the vertical, penetrating the water with their beaks to a depth of 10.1 mm. Then they withdrew their beaks from the water along the angle of immersion and raised their heads to an angle of 54.5” from the vertical, allowing water to flow down their esophagi, as evidenced by visible throat movements. TABLE
I
Descriptive SE for
variables
of drinking
behaviour
of broiler
breeder
chicks
from
5 to 35 days
+
of age (mean
10 birds) Age
in days
Regression equation
5 Distance waterer
to (cm)
(O) Immersion
angle
10
15
5.7
6.6
9.1
(0.3)
(0.3)
(0.1)
161.6 (3.4)
1613.2 (1.5)
168.4 (2.9)
Depth of beak immersion (mm)
10.1
(O) Swallowing
54.5
68.3
70.1
(4.1)
(4.7)
(3.6)
angle
(0.1)
25
20 10.2 (0.0) 164.2 (2.9)
9.6
9.7
8.7
(0.9)
(1.4)
(1.3)
11.3 (0.2) 168.4 (3.0) 10.9
30
35
13.3 (0.4) 157.9 (3.2) 12.5
14.6
Y = 4.07
+ 0.30
(x)
(0.4) 152.3
y = 169.92
-
0.35
(x)
(2.5) 10.6
(0.7)
(0.8)
(1.1)
68.5
75.4
75.2
87.2
(3.8)
(3.3)
(3.7)
(1.8)
y = 9.99
Y = 54.57
+ 0.02
+ 0.84
(x)
(x)
Over the 5-week period, action patterns were modified gradually. Distance from the waterer and swallowing angle increased in a linear fashion to 14.6 cm and 87.2”) respectively, at 5 weeks, whereas immersion angle increased to 168.4” at lo-15 days and then declined to 152.3” at 5 weeks (Table I). Depth of beak immersion remained fairly constant over time. The older birds, rather than directly witbdrawing their beaks from the water, made a “scooping’7 motion with their heads, bringing their beaks closer to a horizontal position. Then they withdrew from the water. Frequency of approach to the waterer was initially high, but declined over the 5-week period (Table II). At the same time, number of drinks per approach to the waterer, water intake per drink and time spent at the waterer
29
Fig. 2. Action patterns involved in obtaining
a drink.
30
per approach were initially low, but increased over the 5 weeks (Table II). These increases more than compensated for the decline in frequency of approach to the waterer, resulting in an increase in water intake per day from Week 1 to Week 5 (Table II). TABLE II Water consumption + SE for 10 birds)
variables for broiler breeder chicks from 1 to 5 weeks of age (mean
Age in weeks 1
2
Frequency of approach to waterer per 24 h
56.6 (4.6)
39.5
Number of drinks per approach to waterer
Regression equation 3
4
5
38.8 (5.1)
20.6 (3.5)
22.4 (2.5)
y = 61.75 - 8.72 (x)
(2) (FEZ)
10.4 (1.0)
23.3 (2.3)
23.4 (2.3)
y = -1.75
Water intake per drink (g)
0.13 (0.01)
0.21 (0.01)
0.30 (0.02)
0.38 (0.03)
y = 0.08 + 0.06 (x)
(0.02)
Time spent at waterer per ap preach (min)
0.94 (0.04)
1.13 (0.07)
1.36 (0.11)
3.36 (0.42)
2.97 (0.37)
y = 0.065 + 0.629
Total water intake per bird per day (9)
28.39
67.62 (4.02)
107.17 (4.99)
133.37 (13.02)
197.01 (12.08)
(2.08)
(4.3)
0.29
y = -14.18
+ 5.26 (x)
(x)
+ 40.30 (x)
The design of the watering apparatus permitted measurement of water consumption of individual group-housed birds. With the aid of camera and video-recorder, monitoring of activity around the waterer was obtained without experimenter-interference. Measurement of head and body positions was facilitated because recorded action of the birds could be “frozen” at any point in the drinking sequence. Water intake could be determined accurately to 0.1 g, with water loss due to spillage and evaporation excluded from the data. Although the results of this study provide important basic information on drinking behaviour, some mention must be made of factors potentially affecting the applicability of the results. The watering apparatus may have affected intake by altering the magnitude of the effects of certain normal behavioural influences on water consumption. For example, sequential individual approach to the waterer could reduce the effect of social facilitation on drinking. In addition, dominance relations probably assumed greater than usual importance in this experiment. It was occasionally observed that a bird in possession of the waterer would be “squeezed out” by another, presumably more dominant, bird. Continuous light, necessary for 24-h video-
31
recording, is also a deviation from normal broiler breeder management practice, and undoubtedly altered the circadian distribution of drinking. Despite these considerations, the results of this study agree with water intake of groups of broilers reported by North (1978), who found an average water consumption of 112.6 g per bird per day over the first 5 weeks of life, comparable to 109.7 g for the present study. However, Patrick and Ferrise (1962) and Kellerup et al. (1965) obtained average intakes of 56 and 61 g per bird per day, respectively. In these experiments, feed consumption and body weight at 5 weeks also averaged 37% lower than in the present study, indicating the probability of a disparity in many of the variables affecting water intake (e.g. growth rate). The watering apparatus used in conjunction with the video-recording system provided a satisfactory method of obtaining detailed, accurate observations of individual drinking behaviour. The descriptive information concerning action patterns involved in obtaining a drink may facilitate future design and construction of improved mechanical waterers for birds. The water intake data may be useful for more precise calculation of amount of waterer space and optimum distribution of waterers in a pen. ACKNOWLEDGEMENTS
The authors wish to express their thanks to the staff of the Arkell Poultry Research Station, University of Guelph, and to Mr. Bruce Webster for their excellent technical assistance, and to the Ontario Ministry of Agriculture and Food for the use of experimental animals. This project was partially supported by NSERC grant No. A6784. REFERENCES Farner, D.S., 1960. Digestion and the digestive system. In: A.J. Marshall (Editor), Biology and Comparative Physiology of Birds. Academic Press, New York, pp. 411-467. Hunt, G.L. and Smith, W.J., 1967. Pecking and initial drinking responses in young domestic fowl. J. Comp. Physiol. Psychol., 64: 230-236. Kellerup, S.U., Parker, J.E. and Arscott, G.H., 1965. Effect of restricted water consumption on broiler chickens. Poult. Sci., 44: 78-83. North, M.O., 1978. Water intake, production and elimination. Poult. Dig., 37: 286-291. Patrick, H. and Ferrise, A., 1962. The water requirements of broilers. Poult. Sci., 41: 1363-1367. Rheingold, H.L. and Hess, E.H., 1957. The chick’s “preference” for some visual properties of water. J. Comp. Physiol. Psychol., 50: 417-421. Savory, C.J., 1978. The relationship between food and water intake and the effects of water restriction on laying Brown Leghorn hens. Br. Poult. Sci., 19: 631-641.
DRINKING
BEHAVIOUR
OF BROILER
25
CHICKS
P.A. ROSS and J.F. HURNIK Department of Animal and Poultry Science, Nl G 2 WI (Canada)
University of Guelph, Guelph, Ontario
(Accepted for publication 29 June 1982)
ABSTRACT Ross, P.A. and Hurnik, J.F., Ethol., 11: 25-31.
1983.
Drinking behaviour of broiler chicks. Appl. Anim.
A study of drinking behaviour of individual broiler breeder chicks from hatching to 5 weeks of age was conducted. The action patterns involved in obtaining a drink as well as water consumption were described quantitatively and qualitatively. Over the experimental period, the action patterns of drinking were modified gradually. Marked changes in immersion angle, swallowing angle and distance from the waterer were evident. All birds made progressively fewer trips to the waterer to take a larger number of higher volume drinks. This information is essential for future design of improved watering equipment to better complement the natural drinking behaviour of broiler chickens.
INTRODUCTION
Water is a nutrient which plays a vital role in all aspects of body metabolism. Maintenance of adequate water consumption is, therefore, a priority function of the body’s homeostatic mechanism. For this reason, knowledge of the normal quantitative and qualitative aspects of drinking behaviour constitute important basic information for any species. Such information can then be utilized as an effective diagnostic tool allowing disruptions, indicative of pathological and psychological upset, to be detected at an early stage. Most current poultry management practices, as well as equipment and facilities used for housing birds, have been designed with only empirical knowledge of instinctive behaviour patterns of poultry. Although a few studies describe drinking movements (Rheingold and Hess, 1957; Farner, 1960; Hunt and Smith, 1967), and discuss individual water consumption (Savory, 1978), there is an obvious need for objective, precise data. The scarcity of information on drinking behaviour can be attributed largely to the lack of accurate long-term monitoring techniques in the past. Thus, the following study was conducted: (1) to describe the action patterns involved in drinking behaviour of young broiler breeders; (2) to obtain accurate information on water consumption variables.
0304-3762/83/$03.00
o
1983 Elsevier Science Publishers B.V.
26
MATERIALS
Subjects
AND METHODS
and management
Ten one-day-old broiler breeder chicks were fitted with large wingbands which were clearly visible on a video-playback screen. They were housed in a circular area (1.2 m in diameter) formed by a 45-cm high cardboard chick guard and equipped with an infrared brooder heat lamp and trough feeder. Ambient temperature was kept constant at 25°C. The birds were given continuous light at an intensity of 300 lux to permit 24-h video-recording. Starter diet (20% C.P., 2970 kcal M.E./kg) was provided ad libitum. The chicks were maintained in this manner until the end of the study at 5 weeks of age. Apparatus
The chick guard opened into an alley, bordered by calibrated, clear plexiglass walls, which led to the waterer. The width of the alley was such that only one bird could approach the waterer at a time, and was progressively increased from 7 to 14 cm as the birds grew. Similarly, the length of the alley was increased from 13 to 18 cm over the course of the study. Water for the experimental birds was provided in a calibrated, clear plastic bowl. The waterer was positioned on a Mettler electronic digital scale, and changes in water consumption were recorded to 0.1 g. The position of the scale was adjusted weekly to maintain the edge of the water bowl at the breast level of the chicks. A clock was positioned above the scale. Variables and statistics
Video-recordings of individual bird activity at the waterer were obtained for two 24-h periods each week. The video equipment consisted of a camera with a wide-angle lens and a Hitachi time-lapse video-recorder. Scaleregistered changes in the weight of the waterer due to drinking were clearly visible on the TV monitor. Observations of drinking behaviour patterns were recorded at 5day intervals, and consisted of individual measures of distance from the waterer when drinking, immersion angle, depth of break immersion while obtaining a drink and swallowing angle. Measurement of these variables was aided by calibrations on both the plexiglass alley and the water bowl. Operationally, these variables were defined as follows: Distance from the waterer was the horizontal distance from the edge of the scale to the foremost leg (the edge of the scale was in line with the edge of the waterer. Immersion angle (Fig. la) was measured from a vertical axis through the eye (vertex) to an imaginary axis projected to the tip of the beak at the point of contact with the water.
27
a
b
Fig. 1. a. Immersion
angle. b. Swallowing
angle.
Depth of beak immersion was measured from the surface of the water to the tip of the beak at maximum depth. Swallowing angle (Fig. lb) was measured from a vertical axis through the eye (vertex) to an imaginary axis projected to the tip of the beak at its highest swallowing elevation. The consumption data obtained for each bird consisted of number of approaches to the waterer per day, number of drinks per approach to the waterer, average water intake per drink, time spent at the waterer per approach and total water consumption per day.
28
Regressions over time were plotted for all consumption and description variables. Since the same birds were observed at each time-period, coefficient of determination of significance tests were not calculated due to lack of independence between observations. RESULTS
AND
DISCUSSION
The results of this study provide information on patterns of drinking behaviour of young broiler breeders. Table I and Fig. 2 illustrate the variation of the above-mentioned drinking parameters over time and the action patterns involved in obtaining a drink. Neonatal chicks oriented to the waterer, approached to a distance of 5.7 cm, then stopped and lowered their heads to an angle of 161.6” from the vertical, penetrating the water with their beaks to a depth of 10.1 mm. Then they withdrew their beaks from the water along the angle of immersion and raised their heads to an angle of 54.5” from the vertical, allowing water to flow down their esophagi, as evidenced by visible throat movements. TABLE
I
Descriptive SE for
variables
of drinking
behaviour
of broiler
breeder
chicks
from
5 to 35 days
+
of age (mean
10 birds) Age
in days
Regression equation
5 Distance waterer
to (cm)
(O) Immersion
angle
10
15
5.7
6.6
9.1
(0.3)
(0.3)
(0.1)
161.6 (3.4)
1613.2 (1.5)
168.4 (2.9)
Depth of beak immersion (mm)
10.1
(O) Swallowing
54.5
68.3
70.1
(4.1)
(4.7)
(3.6)
angle
(0.1)
25
20 10.2 (0.0) 164.2 (2.9)
9.6
9.7
8.7
(0.9)
(1.4)
(1.3)
11.3 (0.2) 168.4 (3.0) 10.9
30
35
13.3 (0.4) 157.9 (3.2) 12.5
14.6
Y = 4.07
+ 0.30
(x)
(0.4) 152.3
y = 169.92
-
0.35
(x)
(2.5) 10.6
(0.7)
(0.8)
(1.1)
68.5
75.4
75.2
87.2
(3.8)
(3.3)
(3.7)
(1.8)
y = 9.99
Y = 54.57
+ 0.02
+ 0.84
(x)
(x)
Over the 5-week period, action patterns were modified gradually. Distance from the waterer and swallowing angle increased in a linear fashion to 14.6 cm and 87.2”) respectively, at 5 weeks, whereas immersion angle increased to 168.4” at lo-15 days and then declined to 152.3” at 5 weeks (Table I). Depth of beak immersion remained fairly constant over time. The older birds, rather than directly witbdrawing their beaks from the water, made a “scooping’7 motion with their heads, bringing their beaks closer to a horizontal position. Then they withdrew from the water. Frequency of approach to the waterer was initially high, but declined over the 5-week period (Table II). At the same time, number of drinks per approach to the waterer, water intake per drink and time spent at the waterer
29
Fig. 2. Action patterns involved in obtaining
a drink.
30
per approach were initially low, but increased over the 5 weeks (Table II). These increases more than compensated for the decline in frequency of approach to the waterer, resulting in an increase in water intake per day from Week 1 to Week 5 (Table II). TABLE II Water consumption + SE for 10 birds)
variables for broiler breeder chicks from 1 to 5 weeks of age (mean
Age in weeks 1
2
Frequency of approach to waterer per 24 h
56.6 (4.6)
39.5
Number of drinks per approach to waterer
Regression equation 3
4
5
38.8 (5.1)
20.6 (3.5)
22.4 (2.5)
y = 61.75 - 8.72 (x)
(2) (FEZ)
10.4 (1.0)
23.3 (2.3)
23.4 (2.3)
y = -1.75
Water intake per drink (g)
0.13 (0.01)
0.21 (0.01)
0.30 (0.02)
0.38 (0.03)
y = 0.08 + 0.06 (x)
(0.02)
Time spent at waterer per ap preach (min)
0.94 (0.04)
1.13 (0.07)
1.36 (0.11)
3.36 (0.42)
2.97 (0.37)
y = 0.065 + 0.629
Total water intake per bird per day (9)
28.39
67.62 (4.02)
107.17 (4.99)
133.37 (13.02)
197.01 (12.08)
(2.08)
(4.3)
0.29
y = -14.18
+ 5.26 (x)
(x)
+ 40.30 (x)
The design of the watering apparatus permitted measurement of water consumption of individual group-housed birds. With the aid of camera and video-recorder, monitoring of activity around the waterer was obtained without experimenter-interference. Measurement of head and body positions was facilitated because recorded action of the birds could be “frozen” at any point in the drinking sequence. Water intake could be determined accurately to 0.1 g, with water loss due to spillage and evaporation excluded from the data. Although the results of this study provide important basic information on drinking behaviour, some mention must be made of factors potentially affecting the applicability of the results. The watering apparatus may have affected intake by altering the magnitude of the effects of certain normal behavioural influences on water consumption. For example, sequential individual approach to the waterer could reduce the effect of social facilitation on drinking. In addition, dominance relations probably assumed greater than usual importance in this experiment. It was occasionally observed that a bird in possession of the waterer would be “squeezed out” by another, presumably more dominant, bird. Continuous light, necessary for 24-h video-
31
recording, is also a deviation from normal broiler breeder management practice, and undoubtedly altered the circadian distribution of drinking. Despite these considerations, the results of this study agree with water intake of groups of broilers reported by North (1978), who found an average water consumption of 112.6 g per bird per day over the first 5 weeks of life, comparable to 109.7 g for the present study. However, Patrick and Ferrise (1962) and Kellerup et al. (1965) obtained average intakes of 56 and 61 g per bird per day, respectively. In these experiments, feed consumption and body weight at 5 weeks also averaged 37% lower than in the present study, indicating the probability of a disparity in many of the variables affecting water intake (e.g. growth rate). The watering apparatus used in conjunction with the video-recording system provided a satisfactory method of obtaining detailed, accurate observations of individual drinking behaviour. The descriptive information concerning action patterns involved in obtaining a drink may facilitate future design and construction of improved mechanical waterers for birds. The water intake data may be useful for more precise calculation of amount of waterer space and optimum distribution of waterers in a pen. ACKNOWLEDGEMENTS
The authors wish to express their thanks to the staff of the Arkell Poultry Research Station, University of Guelph, and to Mr. Bruce Webster for their excellent technical assistance, and to the Ontario Ministry of Agriculture and Food for the use of experimental animals. This project was partially supported by NSERC grant No. A6784. REFERENCES Farner, D.S., 1960. Digestion and the digestive system. In: A.J. Marshall (Editor), Biology and Comparative Physiology of Birds. Academic Press, New York, pp. 411-467. Hunt, G.L. and Smith, W.J., 1967. Pecking and initial drinking responses in young domestic fowl. J. Comp. Physiol. Psychol., 64: 230-236. Kellerup, S.U., Parker, J.E. and Arscott, G.H., 1965. Effect of restricted water consumption on broiler chickens. Poult. Sci., 44: 78-83. North, M.O., 1978. Water intake, production and elimination. Poult. Dig., 37: 286-291. Patrick, H. and Ferrise, A., 1962. The water requirements of broilers. Poult. Sci., 41: 1363-1367. Rheingold, H.L. and Hess, E.H., 1957. The chick’s “preference” for some visual properties of water. J. Comp. Physiol. Psychol., 50: 417-421. Savory, C.J., 1978. The relationship between food and water intake and the effects of water restriction on laying Brown Leghorn hens. Br. Poult. Sci., 19: 631-641.