- Email: [email protected]
Effect of Heat Stress and Diet Composition on Performance of White Leghorn Hens
Effect of Heat Stress and Diet Composition on Performance of White Leghorn Hens M. A. TANOR, S. LEESON, and J. D. SUMMERS Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada NIG 2W1 (Received for publication July 6, 1982)
1984 Poultry Science 63:304-310 INTRODUCTION Since Strominger and Brobeck (195 3) postulated t h e t h e r m o s t a t i c regulation of feed intake, m a n y researchers have s h o w n t h a t feed c o n s u m p t i o n is inversely related t o environm e n t a l t e m p e r a t u r e (Campos et ah, I 9 6 0 ; Prince et ah, 1 9 6 5 ; V o h r a et ah, 1 9 7 9 ) . High environmental t e m p e r a t u r e s or cyclic temperat u r e s have been reported t o lower egg p r o d u c t i o n and decrease egg weight and egg shell thickness (de A n d r a d e et ah, 1 9 7 6 , 1 9 7 7 ; Cowan and Michie, 1 9 8 0 ; Miller and S u n d e , 1 9 7 5 ; J o n e s et ah, 1 9 7 6 ) . Dietary energy c o n c e n t r a t i o n is also a major factor influencing feed intake ( Y a m o t o and Brobeck, 1 9 6 5 ; National Research Council, 1 9 7 7 ) and studies have shown t h a t changing hens from a low energy t o a high energy diet results in an i m m e d i a t e r e d u c t i o n in feed c o n s u m p t i o n (Ahmed, 1 9 7 3 ; J o n e s et ah, 1976). Payne ( 1 9 6 6 ) r e p o r t e d t h a t t h e adverse effects of a constant high environmental t e m p e r a t u r e could b e minimized b y a p p r o p r i a t e dietary modification, de A n d r a d e et ah ( 1 9 7 6 ) d e m o n s t r a t e d t h a t a high n u t r i e n t density diet resulted in improved egg weight and egg p r o d u c t i o n during heat stress, as c o m p a r e d t o a
regular t y p e laying diet. Charles and D u k e ( 1 9 8 1 ) reported t h a t increased dietary p h o s p h o r u s was beneficial for birds housed in a h o t environment. T h e r e are few studies reported where b o t h diet modification and heat stress have been studied simultaneously with layers. T h u s , t h e present s t u d y was u n d e r t a k e n t o look at t h e p o t e n t i a l of diet modification as a means of ameliorating t h e adverse effects of short t e r m heat stress on layers. MATERIALS AND METHODS Commercial strain Single C o m b White Leghorn (SCWL) pullets, 18 weeks of age, were distributed at r a n d o m t o individual 2 0 X 35 cm cages maintained in o n e of t h r e e environmental chambers. Heat stress was imposed in one of t h e chambers at 2 1 , 2 5 , and 33 weeks of age, a p p r o x i m a t i n g times of prepeak, peak, and p o s t p e a k egg p r o d u c t i o n , respectively. Sixty-four birds in each c h a m b e r were assigned one of four diets, with each diet being offered t o four g r o u p s of four adjacent caged birds arranged in a Latin square design. Relative h u m i d i t y was k e p t at 50% t h r o u g h o u t t h e trial. Each e x p e r i m e n t was divided into five t i m e periods. T h e first was a pretest period of 7 days
304
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
ABSTRACT A total of 192 Single Comb White Leghorn pullets were divided into three groups to study the effect of heat stress and diet composition on feed intake and laying performance at 21, 25, and 33 weeks of age. For each age group all birds were fed a control diet [17.1% crude protein (CP), 2770 kcal metabolizable energy (ME)/kg] for a 7-day period. During this time they were kept at a temperature of 18 C. The temperature was then immediately increased to 35 C, and groups of 16 birds offered either the control diet, a high protein diet (43.5% CP), a high energy diet (3371 kcal ME/kg), or a diet of high nutrient density (28.3% CP, 2842 kcal ME/kg, and 6.5% Ca) for a 3-day period. After the 3-day test period, temperature was returned to 18 C, although birds were still offered the experimental diets for an additional 4 days prior to returning to the control diet. Production parameters were measured for individual birds. Feed consumption, egg production (except for the 21-week-old birds), egg weight, and egg shell thickness decreased (P<.05) with heat stress. Increases in energy and calcium intake helped partially to maintain normal egg production, egg weight, and egg shell deformation. Egg weight and egg shell deformation returned to pretest levels within an 8-week postexperimental period. With the exception of those birds receiving the control and high nutrient density diets at 21 weeks of age, data collected over the test periods showed that heat stress caused a significant reduction (P<.05) in liveweight of birds. (Key words: heat stress, layer, feed consumption, egg production, egg weight)
HEAT STRESS AND DIET
Feed and water were provided ad libitum and the birds received 14 hr light per day. During early production (21 weeks of age) all experimental diets were pelleted while at latter ages mash diets were used. Feed consumption was measured for individual birds for 17 days (periods 1 to 4) as described by Hurnik et al. (1977). Crude protein, metabolizable energy, and calcium intakes were calculated from feed intake data. All eggs were weighed and shell deformation recorded (Summers et al., 1976). Birds were weighed on the Days 1 and 17 of the experiment. After 17 days on experiment, egg weight and deformation were recorded weekly. Ten birds died during the peak production phase, and their initial data were discarded. Data obtained were analyzed by analysis of
TABLE 1. Ingredient composition of diets Diet 4,
Diet 2, Diet 1 Ingredients
Fish meal (60%) Meat meal (50%) Soya (48%) Wheat Corn Animal and vegetable blend fat Limestone Calcium phosphate Iodized salt (.015% KI) Vitamin mix 1 Mineral mix 2 DL-Methionine L-Lysine (HC1) Alpha-floc (cellulose)
Control
high crude protein
21.0 20.0 46.45
88.25
1.0 8.0 1.5 .25 .5 .25 .05
1.0 8.0 1.5 .25 .5 .25 .25
Diet 3, high energy
20.0 59.28 10.0 8.0 1.5 .25 .5 .25
high nutrient density
5.0 10.0 39.0 10.0 9.9 11.0 13.5 1.0 .5 .1
.22 1.0 100.00
100.00
100.00
100.00
17.1 2770 3.47 .47 .34 .25 .59 .87
43.5 2388 3.47 .47 .87 .53 1.40 2.52
7.9 3371 3.47 .47 .16 .10 .26 .39
28.3 2842 6.5 .86 .57 .46 1.03 1.95
Calculated analysis Protein, % ME, kcal/kg Calcium, % Available phosphorus, % Methionine, % Cystine, % Total sulphur amino acids, % Lysine, %
'Vitamin premix supplied the following per kilogram of diet: vitamin A, 8000 IU; vitamin D 3 , 1600 IU; vitamin E, 11.0 mg; riboflavin, 9.0 mg; d-calcium pantothenate, 11.0 mg; vitamin B 12 , 13.0 ;ug; niacin, 26.0 mg; choline chloride, 900 mg; vitamin K, 1.5 mg; folic acid, 1.5 mg; biotin, .25 mg; santoquin, 125 mg. 2 Mineral premix supplied the following per kilogram of diet: manganese, 55 mg; zinc, 50.0 mg; copper, 5.0 mg; iron, 30.0 mg.
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
during which time birds received a control corn-soy diet (Table 1) with room temperature maintained at 18 C. One of four diets was offered on day 8 to 10 (3 days) when room temperature was increased to 35 C (Period 2). These diets were: a) control diet, b) high protein (high CP), c) high energy, or d) high nutrient density (HND) (Table 1). During the third period from 11 to 14 days (4 days), temperature was returned to normal (18 C), although birds still received the experimental diets. The fourth period was a posttest period (Days 15 to 17) when birds were returned to the control diet. Birds were maintained an additional 8 weeks on the control diet at the normal temperature; this was designated as the fifth period.
305
306
TANOR ET AL.
variance as outlined by Steel and Torrie (1960) and where significance occurred, Duncan's multiple range test was applied. RESULTS
Egg size increased during the 8-week posttest period, and during postpeak production those birds previously consuming the high CP diet laid significantly (P<.05) heavier eggs than birds from the HND diet. Egg Shell Deformation. Egg shell quality was the parameter most adversely affected by heat stress. During the second and third periods many shell-less eggs were produced. Egg shell deformation values varied widely within each production phase and period. During the prepeak production phase, birds receiving the high CP and high energy diets immediately following the heat stress period produced significantly (P<.05) more thin-shelled eggs than the control birds. During the peak production phase, birds receiving the high CP diet did not show as rapid a return to normal egg shell deformation values, after heat stress, as did birds from other dietary treatments. At postpeak, consumption of the high energy and high CP diets resulted in poorer shell quality both during and immediately following heat stress (Table 3). There were no differences for egg shell deformation during the 8-week posttest period (P>.05). Body Weights. Apart from those birds fed the control and HND diets, during the prepeak production phase, all birds lost weight in response to heat stress (Table 3). At peak production there was no significant difference in body weight change due to diet. After peak egg production all birds lost weight, although this loss was more pronounced (P<.01) for those birds consuming the high CP and high energy diets during the period of heat stress. DISCUSSION The reduction in feed intake with heat stress confirms earlier reports (Payne, 1966; de
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
Feed Consumption. There was no difference (P>.05) in feed intake during the 7-day pretest period for the 3 age groups (Table 2). Heat stress and a change in diet composition decreased feed intake. Regardless of age, birds consumed more (P<,05) of the control diet than the test diets during and immediately following the heat stress (Period 2). During the prepeak production phase, birds consumed more (P<.05) HND diet relative to high CP and high energy diets during the heat stress period. Feed consumption values immediately following the heat stress period (Period 3) varied for each production phase. During prepeak production, birds consumed more (P<.05) of the control and HND diets relative to high CP and high energy diets (Table 2). There was no diet effect on feed consumption during this period at peak egg production; during postpeak production, birds on the control and HND diets consumed similar quantities of feed and significantly more than those fed high CP and high energy diets. During the 4-day posttest period there was no significant difference in feed consumption for any of the production phases. Egg Production. The youngest birds increased egg production during heat stress (Table 3). Immediately following the heat stress period, egg production decreased; it was most severe (P<.01) for birds eating the high CP and high energy diets relative to birds fed the control. A similar picture was noted for the fourth period (posttest). Birds at peak production showed decreased egg output during the heat stress period (Table 3). However, immediately following heat stress, egg production increased for all experiment diets (P>.05). During the postpeak phase, birds again showed decreased egg output during heat stress. During the period immediately following heat stress, birds receiving the high CP diet produced significantly (P<.05) less eggs relative to birds fed other diet treatments. This result was also true during the 3-day posttest period for those birds that had previously received the high CP and high energy diet. All birds showed increased egg production during the 8-week posttest period with no indication of any previous diet effects.
Egg Weight. Diet and heat stress had no effect on egg weight (P>.05) during the first three periods of the trial (Table 3). Throughout the 3-day posttest period at prepeak production, birds previously fed the control and HND diets produced significantly (P<.05) heavier eggs than birds previously fed the high CP and high energy diets. During peak production, there was no diet effect on egg weight (Table 3). At postpeak production, when birds were returned to control conditions (Period 4), those previously receiving the high energy and HND diet produced significantly (P<.05) smaller eggs than the control birds.
4.95a 3.40 3.10 3.30 3.67
143b 213a 57b 112b 208a 273 249 264 294
13.Ob 10.3b 2.5C
21.6a
16.7 15.2 15.0 17.9
76a 24b 33b
76*
Control High CP High energy High nutrient density
3.
1
IA
98 102 107 105
83
59a 3 8b 46b
See Tabic 1.
' ' Means within each column and test period followed by different letters are significantly different ( P < . 0 5 ) .
4. Posttest, 3 days
98 89 95 105
2.65 1 ' .80C 1.13 c
133b
14.9a
53b
Control Control Control Control
88 88 79
3.40a
85<--
Experimental diet, 4 days
34b
2.20b 1.23C 1.33C
178a
10.8b 15.4a 3.ic
64a 36C 40e
Control High CP High energy High nutrient density
2. Heat stress and experimental diet, 3 days
l-i
Kg/Ody) 97 102 102 99
/IT'
2.83 3.13 2.99 3.13
227 251 240 252
(kcal/day)
13.8 15.4 14.6 15.4
(g/clayj
81 90 96 90
Control Control Control Control
1. Pretest, 7 days
Feed intake
Diet fed'
Ca intake
Period
Energy intake
Feed intake
Crude protein intake
and nutrient
16.7 17.3 18.1 17.9
23.4b
15.0'-' 38.3a 6.1d
9.6b
10.0b 16.6a 3.5C
16.5 17.4 17.3 16.9
crude protein intake
274 284 297 293
2 26 be
246ab 210C 266a
93 b
165a 9lb 154a
271 285 285 277
(kcal/day)
Energy intake
2
2 1 1
C
intake of SC
Peak producl:ion phase
of heat stress and diets on feed consumption
Prepeak production phase
TABLE 2. The effect
d from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
Control Control Control Control
5. Posttest, 4—60 days
22 24 25 21 23 22 22 24
50.5
51.8 47.lb 45.2b 51.1*
55.2 57.1 56.0 57.9
84a 4 39c 56b
69ab
9ia 22c 42bc 65*b
3lbc
26c 3 5ab 4ia
51.0
49.3 49.8 48.5
96
7b -79a -73a 10b 94 92 91 99
90 83 83 81
67
73 57 79
See Table 1.
' ' Means within each column and test period followed by different letters are significantly different (P<.05).
HHA% = Hen-housed average, percent.
2
1
91 90 94 95
Control Control Control Control
4. Posttest, 3 days
53
24a
Control High CP High energy High nutrient density
3. Experimental diet, 4 days
57 55 57
22b 24a 23 ab
50.2 50.5 49.7
92 90 94
Control High CP High energy High nutrient density
2. Heat stress a n d experimental diet, 3 days
99 96 91 99
(HHA%)
22 21 21 22
(g)
(Mm)
1. Pretest, 7 days
49.4 50.0 48.0 51.0
Control Control Control Control
74 82 83 84
Diet fed 1
Period
Egg production
(HHA%) 2
A Body weight
Egg weight
Egg production
Shell deformation
Prepeak p r o d u c t i o n phase
55.8 57.0 58.0 57.1
51.0 50.6 50.7 49.5
48.4
49.2 50.7 49.7
53.8
52.6 53.3 55.2
53.3 55.0 55.4 54.4
(g)
Egg weight
22 23 24 24
2lb 25a 22 f l b 2lb
26ab
24b 33a 28ab
42
38 39 33
22 24 23 24
(Mm)
Shell deformation
Peak p r o d u c t i o n phase
TABLE 3. The effect of heat stress and diets on laying performance and body weight of Single Comb
rom http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
HEAT STRESS AND DIET
reports (Vohra et al, 1979; de Andrade et al., 1976, 1977). Although heat stress decreased egg weight, a diet effect was only observed in the period following the heat stress for birds at prepeak and postpeak production phases. From studies involving pair feeding, Smith and Oliver (1972) proposed that decreased egg weight was not solely due to reduced feed intake. In the present study, age also appeared to influence egg weight as there was no diet effect during the peak production phase, but after this time, birds previously receiving the high CP diet laid significantly (P<.05) heavier eggs than birds previously fed the HND diet. The effect of high environmental temperature on egg shell quality has been well documented (Miller and Sunde, 1975; Wolfenson et al., 1979). de Andrade et al. (1976, 1977) found that shell quality was not maintained at constant elevated temperatures. A fall in plasma calcium level was speculated to be the cause for the lower shell quality. In the present study, egg shell quality was not maintained during the period of heat stress nor during the two following periods (7 days); it was significantly (P <.05) affected by both diet and temperature. Birds in the prepeak production phase receiving the control diet during heat stress maintained egg shell quality, whereas birds receiving the HND diet failed to do so despite their higher calcium intake (Table 3). During the peak and postpeak production phases, birds receiving the high CP and high energy diet produced eggs of significantly (P<.05) higher shell deformation. This was probably due, in part, to a low calcium intake. Consumption of control and HND diets resulted in more adequate maintenance of liveweight during the three production phases. Ahmad (1973) maintained birds at 22 or 30 C for 8 weeks and observed less body weight gain for birds maintained in hot climates. Edens (1977) related mortality during acute heat stress to failure of respiratory ventilation. In our study, high mortality of birds at peak production suggests birds of this age may be more susceptible to heat stress. During heat stress and subsequent periods of all three production phases, birds consumed significantly (P<.05) more of the control diet than of the other test diets. Although the HND diet contained substantially elevated concentrations of all nutrients relative to the control diet, the nutrient intake with the latter was greater regardless of bird age. It is assumed that in
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
Andrade et al., 1977; Vohra et al., 1979). Payne (1966) estimated the reduction in feed intake to be 1.6% per degree temperature rise between 17 and 29 C and suggested decreased food consumption was mainly due to a decline in energy requirement rather than an effect of increased temperature per se. Crude protein, energy, and calcium intake were calculated for each period and are shown in Table 2. As expected, the intake of these nutrients differed during the heat stress period and the period immediately following at all three production phases. As previously stated, birds were fed pelleted experimental diets during the prepeak production phase. The high CP pellets were very hard, and it is felt that this may have been a factor for the reduced feed intake noted for some of the test diets. Subsequent trials showed that hens consumed 84% more of a high CP mash diet than of the same diet in pellet form. Daniel and Balnave (1981) reported less of an influence on egg production as compared to feed consumption of laying hens during increased environmental temperature and concluded that food was used more efficiently by the hen under conditions of heat stress. In the present study, there was a significant interaction between heat stress and dietary treatments, with intakes of high CP and high energy diets being more severely depressed relative to other treatments. Although feed intake was reduced during heat stress, birds in the prepeak production phase increased their egg output with no significant difference noted due to dietary treatments. Because egg production decreased in the period following heat stress, the 3day heat stress period may have been too short for an influence on egg production to be noted. This is in keeping with the report of Daniel and Balnave (1981), which indicated that feed intake is affected prior to subsequent loss in egg production. However, Wolfenson et al. (1979) reported that heat stress could directly affect egg production while prolonged heat might act indirectly via a suppression of feed intake. The fact that egg production was reduced at peak production, during the 3-day heat stress period, but was not affected in the prepeak production phase, is probably a reflection of the higher egg mass output and, hence, more rapid depletion of body reserves of the older bird. By and large, birds in peak and postpeak production phases decreased their egg weight in response to heat stress, similar to previous
309
310
TANOR ET AL.
addition to t h e adverse effect of heat per se, diet change was an additional stress o n t h e bird.
REFERENCES
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
Ahmad, M. S., 1973. Effects of environmental temperature and dietary energy on feed intake in chickens. Ph.D. thesis, Univ. Nebraska. Campos, A. C, F. H. Wilcox, and C. S. Shaffner, 1960. The influence of fast and slow rises in ambient temperature on production traits and mortality of laying pullets. Poultry Sci. 39:119-129. Charles, O. W., and S. Duke, 1981. The productive response of Leghorn hens to temperature and phosphorus level. Poultry Sci. 60:1638. (Abstr.) Cowan, P. J., and W. Michie, 1980. Increasing the environmental temperature later in lay performance of the fowl. Br. Poult. Sci. 21:339-343. Daniel, M., and D. Balnave, 1981. Response of laying hens to gradual and abrupt increases in ambient temperature and humidity. Aust. J. Exp. Agric. Anim. Husb. 21:189-195. de Andrade, A. N., J. C. Rogler, W. R. Featherston, and C. W. Alliston, 1976. Influence of constant elevated temperature and diet on egg production and shell quality. Poultry Sci. 55:685-693. de Andrade, A. N., J. C. Rogler, W. R. Featherston, and C. W. Alliston, 1977. Interrelationships between diet and elevated temperature (cyclic or constant) on egg production and shell quality. Poultry Sci. 56:1178-1188. Edens, F. W., 1977. Physiological profile of heat prostration in chickens. Pages 34—53 in Proc. 13th Annu. South. Reg. Avian Environ. Physiol. Bioeng. Study Group. Virginia Polytechnic Inst. State Univ., Blacksburg, VA. Hurnik, J. F., J. D. Summers, B. S. Reinhart, and E. M. Swierczewska, 1977. Effect of age on the performance of laying hens during the first year of production. Poultry Sci. 56:222-230. Jones, J. E., B. L. Hughes, and B. D. Barnett, 1976. Effect of changing dietary energy of environmental temperatures on feed consumption and egg
production of Single Comb White Leghorns. Poultry Sci. 55:274-277. Miller, P. C , and M. L. Sunde, 1975. The effects of precise constant and cyclic environments on shell quality and other lay performance factors with Leghorn pullets. Poultry Sci. 54:36—46. National Research Council, 1977. Nutrient require ments of poultry. No. 1. Nutrient Requirements of the Domestic Animals. 7th rev. ed. Natl. Acad. Sci., Washington, DC. Payne, C. G., 1966. Practical aspects of environmental temperature for laying hens. World's Poultry Sci. J. 22:126-139. Prince, R. P., J. H. Whitaker, L. D. Matterson, and R. E. Luginbuhl, 1965. Response of chickens to temperature and relative humidity environments. Poultry Sci. 4 4 : 7 3 - 7 7 . Smith, A. J., and J. Oliver, 1972. Some nutritional problems associated with egg production at high environmental temperatures. 4. The effect of prolonged exposure to high environmental temperature on the productivity of pullets fed high-energy diets. Rhodesian J. Agric. Res. 10:43-60. Steel, R.G.D., and J. H. Torrie, 1960. Principles and procedures of statistics. McGraw-Hill Book Co., New York, NY. Strominger, J. L., and J. R. Brobeck, 1953. A mechanism of regulation of food intake. Yale J. Biol. Med. 25:383-390. Summers, J. D., R. Grandhi, and S. Leeson, 1976. Calcium and phosphorus requirements of the laying hen. Poultry Sci. 55:402-413. Vohra, R., W. D. Wilson, and T. D. Siopes, 1979. Egg production, feed consumption and maintenance energy requirements of Leghorn hens at temperatures of 15.6 and 26.7 C. Poultry Sci. 5 8 : 6 7 4 680. Wolfenson, D., F. E. Frei, N. Snapir, and A. Nerman, 1979. Effect of diurnal or nocturnal heat stress on egg formation. Poultry Sci. 20:167-174. Yamamoto, W. S., and J. R. Brobeck, 1965. Physiological Controls and Regulations. W. B. Saunders Co., Philadelphia, PA.
1984 Poultry Science 63:304-310 INTRODUCTION Since Strominger and Brobeck (195 3) postulated t h e t h e r m o s t a t i c regulation of feed intake, m a n y researchers have s h o w n t h a t feed c o n s u m p t i o n is inversely related t o environm e n t a l t e m p e r a t u r e (Campos et ah, I 9 6 0 ; Prince et ah, 1 9 6 5 ; V o h r a et ah, 1 9 7 9 ) . High environmental t e m p e r a t u r e s or cyclic temperat u r e s have been reported t o lower egg p r o d u c t i o n and decrease egg weight and egg shell thickness (de A n d r a d e et ah, 1 9 7 6 , 1 9 7 7 ; Cowan and Michie, 1 9 8 0 ; Miller and S u n d e , 1 9 7 5 ; J o n e s et ah, 1 9 7 6 ) . Dietary energy c o n c e n t r a t i o n is also a major factor influencing feed intake ( Y a m o t o and Brobeck, 1 9 6 5 ; National Research Council, 1 9 7 7 ) and studies have shown t h a t changing hens from a low energy t o a high energy diet results in an i m m e d i a t e r e d u c t i o n in feed c o n s u m p t i o n (Ahmed, 1 9 7 3 ; J o n e s et ah, 1976). Payne ( 1 9 6 6 ) r e p o r t e d t h a t t h e adverse effects of a constant high environmental t e m p e r a t u r e could b e minimized b y a p p r o p r i a t e dietary modification, de A n d r a d e et ah ( 1 9 7 6 ) d e m o n s t r a t e d t h a t a high n u t r i e n t density diet resulted in improved egg weight and egg p r o d u c t i o n during heat stress, as c o m p a r e d t o a
regular t y p e laying diet. Charles and D u k e ( 1 9 8 1 ) reported t h a t increased dietary p h o s p h o r u s was beneficial for birds housed in a h o t environment. T h e r e are few studies reported where b o t h diet modification and heat stress have been studied simultaneously with layers. T h u s , t h e present s t u d y was u n d e r t a k e n t o look at t h e p o t e n t i a l of diet modification as a means of ameliorating t h e adverse effects of short t e r m heat stress on layers. MATERIALS AND METHODS Commercial strain Single C o m b White Leghorn (SCWL) pullets, 18 weeks of age, were distributed at r a n d o m t o individual 2 0 X 35 cm cages maintained in o n e of t h r e e environmental chambers. Heat stress was imposed in one of t h e chambers at 2 1 , 2 5 , and 33 weeks of age, a p p r o x i m a t i n g times of prepeak, peak, and p o s t p e a k egg p r o d u c t i o n , respectively. Sixty-four birds in each c h a m b e r were assigned one of four diets, with each diet being offered t o four g r o u p s of four adjacent caged birds arranged in a Latin square design. Relative h u m i d i t y was k e p t at 50% t h r o u g h o u t t h e trial. Each e x p e r i m e n t was divided into five t i m e periods. T h e first was a pretest period of 7 days
304
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
ABSTRACT A total of 192 Single Comb White Leghorn pullets were divided into three groups to study the effect of heat stress and diet composition on feed intake and laying performance at 21, 25, and 33 weeks of age. For each age group all birds were fed a control diet [17.1% crude protein (CP), 2770 kcal metabolizable energy (ME)/kg] for a 7-day period. During this time they were kept at a temperature of 18 C. The temperature was then immediately increased to 35 C, and groups of 16 birds offered either the control diet, a high protein diet (43.5% CP), a high energy diet (3371 kcal ME/kg), or a diet of high nutrient density (28.3% CP, 2842 kcal ME/kg, and 6.5% Ca) for a 3-day period. After the 3-day test period, temperature was returned to 18 C, although birds were still offered the experimental diets for an additional 4 days prior to returning to the control diet. Production parameters were measured for individual birds. Feed consumption, egg production (except for the 21-week-old birds), egg weight, and egg shell thickness decreased (P<.05) with heat stress. Increases in energy and calcium intake helped partially to maintain normal egg production, egg weight, and egg shell deformation. Egg weight and egg shell deformation returned to pretest levels within an 8-week postexperimental period. With the exception of those birds receiving the control and high nutrient density diets at 21 weeks of age, data collected over the test periods showed that heat stress caused a significant reduction (P<.05) in liveweight of birds. (Key words: heat stress, layer, feed consumption, egg production, egg weight)
HEAT STRESS AND DIET
Feed and water were provided ad libitum and the birds received 14 hr light per day. During early production (21 weeks of age) all experimental diets were pelleted while at latter ages mash diets were used. Feed consumption was measured for individual birds for 17 days (periods 1 to 4) as described by Hurnik et al. (1977). Crude protein, metabolizable energy, and calcium intakes were calculated from feed intake data. All eggs were weighed and shell deformation recorded (Summers et al., 1976). Birds were weighed on the Days 1 and 17 of the experiment. After 17 days on experiment, egg weight and deformation were recorded weekly. Ten birds died during the peak production phase, and their initial data were discarded. Data obtained were analyzed by analysis of
TABLE 1. Ingredient composition of diets Diet 4,
Diet 2, Diet 1 Ingredients
Fish meal (60%) Meat meal (50%) Soya (48%) Wheat Corn Animal and vegetable blend fat Limestone Calcium phosphate Iodized salt (.015% KI) Vitamin mix 1 Mineral mix 2 DL-Methionine L-Lysine (HC1) Alpha-floc (cellulose)
Control
high crude protein
21.0 20.0 46.45
88.25
1.0 8.0 1.5 .25 .5 .25 .05
1.0 8.0 1.5 .25 .5 .25 .25
Diet 3, high energy
20.0 59.28 10.0 8.0 1.5 .25 .5 .25
high nutrient density
5.0 10.0 39.0 10.0 9.9 11.0 13.5 1.0 .5 .1
.22 1.0 100.00
100.00
100.00
100.00
17.1 2770 3.47 .47 .34 .25 .59 .87
43.5 2388 3.47 .47 .87 .53 1.40 2.52
7.9 3371 3.47 .47 .16 .10 .26 .39
28.3 2842 6.5 .86 .57 .46 1.03 1.95
Calculated analysis Protein, % ME, kcal/kg Calcium, % Available phosphorus, % Methionine, % Cystine, % Total sulphur amino acids, % Lysine, %
'Vitamin premix supplied the following per kilogram of diet: vitamin A, 8000 IU; vitamin D 3 , 1600 IU; vitamin E, 11.0 mg; riboflavin, 9.0 mg; d-calcium pantothenate, 11.0 mg; vitamin B 12 , 13.0 ;ug; niacin, 26.0 mg; choline chloride, 900 mg; vitamin K, 1.5 mg; folic acid, 1.5 mg; biotin, .25 mg; santoquin, 125 mg. 2 Mineral premix supplied the following per kilogram of diet: manganese, 55 mg; zinc, 50.0 mg; copper, 5.0 mg; iron, 30.0 mg.
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
during which time birds received a control corn-soy diet (Table 1) with room temperature maintained at 18 C. One of four diets was offered on day 8 to 10 (3 days) when room temperature was increased to 35 C (Period 2). These diets were: a) control diet, b) high protein (high CP), c) high energy, or d) high nutrient density (HND) (Table 1). During the third period from 11 to 14 days (4 days), temperature was returned to normal (18 C), although birds still received the experimental diets. The fourth period was a posttest period (Days 15 to 17) when birds were returned to the control diet. Birds were maintained an additional 8 weeks on the control diet at the normal temperature; this was designated as the fifth period.
305
306
TANOR ET AL.
variance as outlined by Steel and Torrie (1960) and where significance occurred, Duncan's multiple range test was applied. RESULTS
Egg size increased during the 8-week posttest period, and during postpeak production those birds previously consuming the high CP diet laid significantly (P<.05) heavier eggs than birds from the HND diet. Egg Shell Deformation. Egg shell quality was the parameter most adversely affected by heat stress. During the second and third periods many shell-less eggs were produced. Egg shell deformation values varied widely within each production phase and period. During the prepeak production phase, birds receiving the high CP and high energy diets immediately following the heat stress period produced significantly (P<.05) more thin-shelled eggs than the control birds. During the peak production phase, birds receiving the high CP diet did not show as rapid a return to normal egg shell deformation values, after heat stress, as did birds from other dietary treatments. At postpeak, consumption of the high energy and high CP diets resulted in poorer shell quality both during and immediately following heat stress (Table 3). There were no differences for egg shell deformation during the 8-week posttest period (P>.05). Body Weights. Apart from those birds fed the control and HND diets, during the prepeak production phase, all birds lost weight in response to heat stress (Table 3). At peak production there was no significant difference in body weight change due to diet. After peak egg production all birds lost weight, although this loss was more pronounced (P<.01) for those birds consuming the high CP and high energy diets during the period of heat stress. DISCUSSION The reduction in feed intake with heat stress confirms earlier reports (Payne, 1966; de
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
Feed Consumption. There was no difference (P>.05) in feed intake during the 7-day pretest period for the 3 age groups (Table 2). Heat stress and a change in diet composition decreased feed intake. Regardless of age, birds consumed more (P<,05) of the control diet than the test diets during and immediately following the heat stress (Period 2). During the prepeak production phase, birds consumed more (P<.05) HND diet relative to high CP and high energy diets during the heat stress period. Feed consumption values immediately following the heat stress period (Period 3) varied for each production phase. During prepeak production, birds consumed more (P<.05) of the control and HND diets relative to high CP and high energy diets (Table 2). There was no diet effect on feed consumption during this period at peak egg production; during postpeak production, birds on the control and HND diets consumed similar quantities of feed and significantly more than those fed high CP and high energy diets. During the 4-day posttest period there was no significant difference in feed consumption for any of the production phases. Egg Production. The youngest birds increased egg production during heat stress (Table 3). Immediately following the heat stress period, egg production decreased; it was most severe (P<.01) for birds eating the high CP and high energy diets relative to birds fed the control. A similar picture was noted for the fourth period (posttest). Birds at peak production showed decreased egg output during the heat stress period (Table 3). However, immediately following heat stress, egg production increased for all experiment diets (P>.05). During the postpeak phase, birds again showed decreased egg output during heat stress. During the period immediately following heat stress, birds receiving the high CP diet produced significantly (P<.05) less eggs relative to birds fed other diet treatments. This result was also true during the 3-day posttest period for those birds that had previously received the high CP and high energy diet. All birds showed increased egg production during the 8-week posttest period with no indication of any previous diet effects.
Egg Weight. Diet and heat stress had no effect on egg weight (P>.05) during the first three periods of the trial (Table 3). Throughout the 3-day posttest period at prepeak production, birds previously fed the control and HND diets produced significantly (P<.05) heavier eggs than birds previously fed the high CP and high energy diets. During peak production, there was no diet effect on egg weight (Table 3). At postpeak production, when birds were returned to control conditions (Period 4), those previously receiving the high energy and HND diet produced significantly (P<.05) smaller eggs than the control birds.
4.95a 3.40 3.10 3.30 3.67
143b 213a 57b 112b 208a 273 249 264 294
13.Ob 10.3b 2.5C
21.6a
16.7 15.2 15.0 17.9
76a 24b 33b
76*
Control High CP High energy High nutrient density
3.
1
IA
98 102 107 105
83
59a 3 8b 46b
See Tabic 1.
' ' Means within each column and test period followed by different letters are significantly different ( P < . 0 5 ) .
4. Posttest, 3 days
98 89 95 105
2.65 1 ' .80C 1.13 c
133b
14.9a
53b
Control Control Control Control
88 88 79
3.40a
85<--
Experimental diet, 4 days
34b
2.20b 1.23C 1.33C
178a
10.8b 15.4a 3.ic
64a 36C 40e
Control High CP High energy High nutrient density
2. Heat stress and experimental diet, 3 days
l-i
Kg/Ody) 97 102 102 99
/IT'
2.83 3.13 2.99 3.13
227 251 240 252
(kcal/day)
13.8 15.4 14.6 15.4
(g/clayj
81 90 96 90
Control Control Control Control
1. Pretest, 7 days
Feed intake
Diet fed'
Ca intake
Period
Energy intake
Feed intake
Crude protein intake
and nutrient
16.7 17.3 18.1 17.9
23.4b
15.0'-' 38.3a 6.1d
9.6b
10.0b 16.6a 3.5C
16.5 17.4 17.3 16.9
crude protein intake
274 284 297 293
2 26 be
246ab 210C 266a
93 b
165a 9lb 154a
271 285 285 277
(kcal/day)
Energy intake
2
2 1 1
C
intake of SC
Peak producl:ion phase
of heat stress and diets on feed consumption
Prepeak production phase
TABLE 2. The effect
d from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
Control Control Control Control
5. Posttest, 4—60 days
22 24 25 21 23 22 22 24
50.5
51.8 47.lb 45.2b 51.1*
55.2 57.1 56.0 57.9
84a 4 39c 56b
69ab
9ia 22c 42bc 65*b
3lbc
26c 3 5ab 4ia
51.0
49.3 49.8 48.5
96
7b -79a -73a 10b 94 92 91 99
90 83 83 81
67
73 57 79
See Table 1.
' ' Means within each column and test period followed by different letters are significantly different (P<.05).
HHA% = Hen-housed average, percent.
2
1
91 90 94 95
Control Control Control Control
4. Posttest, 3 days
53
24a
Control High CP High energy High nutrient density
3. Experimental diet, 4 days
57 55 57
22b 24a 23 ab
50.2 50.5 49.7
92 90 94
Control High CP High energy High nutrient density
2. Heat stress a n d experimental diet, 3 days
99 96 91 99
(HHA%)
22 21 21 22
(g)
(Mm)
1. Pretest, 7 days
49.4 50.0 48.0 51.0
Control Control Control Control
74 82 83 84
Diet fed 1
Period
Egg production
(HHA%) 2
A Body weight
Egg weight
Egg production
Shell deformation
Prepeak p r o d u c t i o n phase
55.8 57.0 58.0 57.1
51.0 50.6 50.7 49.5
48.4
49.2 50.7 49.7
53.8
52.6 53.3 55.2
53.3 55.0 55.4 54.4
(g)
Egg weight
22 23 24 24
2lb 25a 22 f l b 2lb
26ab
24b 33a 28ab
42
38 39 33
22 24 23 24
(Mm)
Shell deformation
Peak p r o d u c t i o n phase
TABLE 3. The effect of heat stress and diets on laying performance and body weight of Single Comb
rom http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
HEAT STRESS AND DIET
reports (Vohra et al, 1979; de Andrade et al., 1976, 1977). Although heat stress decreased egg weight, a diet effect was only observed in the period following the heat stress for birds at prepeak and postpeak production phases. From studies involving pair feeding, Smith and Oliver (1972) proposed that decreased egg weight was not solely due to reduced feed intake. In the present study, age also appeared to influence egg weight as there was no diet effect during the peak production phase, but after this time, birds previously receiving the high CP diet laid significantly (P<.05) heavier eggs than birds previously fed the HND diet. The effect of high environmental temperature on egg shell quality has been well documented (Miller and Sunde, 1975; Wolfenson et al., 1979). de Andrade et al. (1976, 1977) found that shell quality was not maintained at constant elevated temperatures. A fall in plasma calcium level was speculated to be the cause for the lower shell quality. In the present study, egg shell quality was not maintained during the period of heat stress nor during the two following periods (7 days); it was significantly (P <.05) affected by both diet and temperature. Birds in the prepeak production phase receiving the control diet during heat stress maintained egg shell quality, whereas birds receiving the HND diet failed to do so despite their higher calcium intake (Table 3). During the peak and postpeak production phases, birds receiving the high CP and high energy diet produced eggs of significantly (P<.05) higher shell deformation. This was probably due, in part, to a low calcium intake. Consumption of control and HND diets resulted in more adequate maintenance of liveweight during the three production phases. Ahmad (1973) maintained birds at 22 or 30 C for 8 weeks and observed less body weight gain for birds maintained in hot climates. Edens (1977) related mortality during acute heat stress to failure of respiratory ventilation. In our study, high mortality of birds at peak production suggests birds of this age may be more susceptible to heat stress. During heat stress and subsequent periods of all three production phases, birds consumed significantly (P<.05) more of the control diet than of the other test diets. Although the HND diet contained substantially elevated concentrations of all nutrients relative to the control diet, the nutrient intake with the latter was greater regardless of bird age. It is assumed that in
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
Andrade et al., 1977; Vohra et al., 1979). Payne (1966) estimated the reduction in feed intake to be 1.6% per degree temperature rise between 17 and 29 C and suggested decreased food consumption was mainly due to a decline in energy requirement rather than an effect of increased temperature per se. Crude protein, energy, and calcium intake were calculated for each period and are shown in Table 2. As expected, the intake of these nutrients differed during the heat stress period and the period immediately following at all three production phases. As previously stated, birds were fed pelleted experimental diets during the prepeak production phase. The high CP pellets were very hard, and it is felt that this may have been a factor for the reduced feed intake noted for some of the test diets. Subsequent trials showed that hens consumed 84% more of a high CP mash diet than of the same diet in pellet form. Daniel and Balnave (1981) reported less of an influence on egg production as compared to feed consumption of laying hens during increased environmental temperature and concluded that food was used more efficiently by the hen under conditions of heat stress. In the present study, there was a significant interaction between heat stress and dietary treatments, with intakes of high CP and high energy diets being more severely depressed relative to other treatments. Although feed intake was reduced during heat stress, birds in the prepeak production phase increased their egg output with no significant difference noted due to dietary treatments. Because egg production decreased in the period following heat stress, the 3day heat stress period may have been too short for an influence on egg production to be noted. This is in keeping with the report of Daniel and Balnave (1981), which indicated that feed intake is affected prior to subsequent loss in egg production. However, Wolfenson et al. (1979) reported that heat stress could directly affect egg production while prolonged heat might act indirectly via a suppression of feed intake. The fact that egg production was reduced at peak production, during the 3-day heat stress period, but was not affected in the prepeak production phase, is probably a reflection of the higher egg mass output and, hence, more rapid depletion of body reserves of the older bird. By and large, birds in peak and postpeak production phases decreased their egg weight in response to heat stress, similar to previous
309
310
TANOR ET AL.
addition to t h e adverse effect of heat per se, diet change was an additional stress o n t h e bird.
REFERENCES
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 25, 2015
Ahmad, M. S., 1973. Effects of environmental temperature and dietary energy on feed intake in chickens. Ph.D. thesis, Univ. Nebraska. Campos, A. C, F. H. Wilcox, and C. S. Shaffner, 1960. The influence of fast and slow rises in ambient temperature on production traits and mortality of laying pullets. Poultry Sci. 39:119-129. Charles, O. W., and S. Duke, 1981. The productive response of Leghorn hens to temperature and phosphorus level. Poultry Sci. 60:1638. (Abstr.) Cowan, P. J., and W. Michie, 1980. Increasing the environmental temperature later in lay performance of the fowl. Br. Poult. Sci. 21:339-343. Daniel, M., and D. Balnave, 1981. Response of laying hens to gradual and abrupt increases in ambient temperature and humidity. Aust. J. Exp. Agric. Anim. Husb. 21:189-195. de Andrade, A. N., J. C. Rogler, W. R. Featherston, and C. W. Alliston, 1976. Influence of constant elevated temperature and diet on egg production and shell quality. Poultry Sci. 55:685-693. de Andrade, A. N., J. C. Rogler, W. R. Featherston, and C. W. Alliston, 1977. Interrelationships between diet and elevated temperature (cyclic or constant) on egg production and shell quality. Poultry Sci. 56:1178-1188. Edens, F. W., 1977. Physiological profile of heat prostration in chickens. Pages 34—53 in Proc. 13th Annu. South. Reg. Avian Environ. Physiol. Bioeng. Study Group. Virginia Polytechnic Inst. State Univ., Blacksburg, VA. Hurnik, J. F., J. D. Summers, B. S. Reinhart, and E. M. Swierczewska, 1977. Effect of age on the performance of laying hens during the first year of production. Poultry Sci. 56:222-230. Jones, J. E., B. L. Hughes, and B. D. Barnett, 1976. Effect of changing dietary energy of environmental temperatures on feed consumption and egg
production of Single Comb White Leghorns. Poultry Sci. 55:274-277. Miller, P. C , and M. L. Sunde, 1975. The effects of precise constant and cyclic environments on shell quality and other lay performance factors with Leghorn pullets. Poultry Sci. 54:36—46. National Research Council, 1977. Nutrient require ments of poultry. No. 1. Nutrient Requirements of the Domestic Animals. 7th rev. ed. Natl. Acad. Sci., Washington, DC. Payne, C. G., 1966. Practical aspects of environmental temperature for laying hens. World's Poultry Sci. J. 22:126-139. Prince, R. P., J. H. Whitaker, L. D. Matterson, and R. E. Luginbuhl, 1965. Response of chickens to temperature and relative humidity environments. Poultry Sci. 4 4 : 7 3 - 7 7 . Smith, A. J., and J. Oliver, 1972. Some nutritional problems associated with egg production at high environmental temperatures. 4. The effect of prolonged exposure to high environmental temperature on the productivity of pullets fed high-energy diets. Rhodesian J. Agric. Res. 10:43-60. Steel, R.G.D., and J. H. Torrie, 1960. Principles and procedures of statistics. McGraw-Hill Book Co., New York, NY. Strominger, J. L., and J. R. Brobeck, 1953. A mechanism of regulation of food intake. Yale J. Biol. Med. 25:383-390. Summers, J. D., R. Grandhi, and S. Leeson, 1976. Calcium and phosphorus requirements of the laying hen. Poultry Sci. 55:402-413. Vohra, R., W. D. Wilson, and T. D. Siopes, 1979. Egg production, feed consumption and maintenance energy requirements of Leghorn hens at temperatures of 15.6 and 26.7 C. Poultry Sci. 5 8 : 6 7 4 680. Wolfenson, D., F. E. Frei, N. Snapir, and A. Nerman, 1979. Effect of diurnal or nocturnal heat stress on egg formation. Poultry Sci. 20:167-174. Yamamoto, W. S., and J. R. Brobeck, 1965. Physiological Controls and Regulations. W. B. Saunders Co., Philadelphia, PA.