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The Influence of Intermittent Light on Growth Performance and Other Traits in Young Chicks
The Influence of Intermittent Light on Growth Performance and Other Traits in Young Chicks P. D .
HOOPPAW 1 AND B . L .
GOODMAN
Animal Industries Department, Southern Illinois University, Carbondale, Illinois 62901 (Received for publication March 2, 1976)
POULTRY SCIENCE 55: 2285-2289,
I
NTERMITTENT light with several cycles or periods of light and darkness per day has given inconsistent results when contrasted with continuous light or with one period of light and one period of darkness per day. Favorable results have been reported by Clegg and Sanford (1951), Barrott and Pringle (1951), Centa et al. (1969), Marr et al. (1971), McDaniel (1972), and Cain (1973). Reports indicating only equal or less desirable results include Shutze et al. (1959), Beane etal. (1962, 1965), Cherry and Barwick (1962), Gore et al. (1969), Foshee et al. (1970) and Dorminey (1971). Published reports on the influence of intermittent lighting on both turkeys and market chickens have been reviewed by Buckland (1975). The potential value of the use of intermittent light to the industry indicates that additional work is needed. PROCEDURE Chicks from the Silver Oklabar growthselected strain were placed in a battery
1. Present address: LandO'Lakes, Inc., New Richland, Minnesota 56072.
1976
brooder with continuous light for six days to allow adjustment to feeders and waterers. All chicks were then sorted in weight groups, and then were wingbanded and distributed at random to each treatment. The difference in average weight per chick per treatment was less than one gram. Three trials with 300 straight-run chicks per trial were conducted. The experimental design (Table 1) involved three light restrictions of 1 /2L:3D (one-half hour of light and three hours of darkness) 1L:3D, and 1L:5D as compared to continuous light with total number of hours of light (feeding time) of 3-1 / 2 , 6, 4 and 24 hours, respectively. The trials were conducted in a room which partitioned into four 1.76 x 2.21 in. compartments. Each chick was given approximately 0.06 m.2 of space in the battery and approximately 4.1 cm. of feeding and watering space. Two 25-watt incandescent bulbs were vertically spaced to provide 32 to 54 lux at the edge of the feeders and waterers of the battery brooder. Although some light seepage occurred, observations indicated little, if any, chick activity until the lights were on in that compartment. The light interval within each
2285
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on May 2, 2015
ABSTRACT Treatments of 1/2L:3D, (1/2 hour light and 3 hours darkness), 1L:3D, 1L:5D lighting cycles and continuous light were used in three trials to grow 900 straight-run chicks from 7 to 35 days of age. Chicks on intermittent light had significantly (P < 0.05) greater gains than those on continuous light. There was no significant difference among treatments with intermittent light. Feed conversion for 1/2L:3D and 1L:5D treatments was significantly better than for the other two treatments. Weights of crop and gizzard contents at the end of dark period (8:00 a.m.) were not significantly different among treatments; however, at the end of the light (feeding) period, at 8:30 or 9:00 a.m., chicks on intermittent light generally had significantly more feed and fluid in the crop, but not in the gizzard, than chicks on continuous light. The crop (tissue) was generally significantly heavier in chicks from the intermittent light treatments. There was no significant difference among treatments for gizzard (tissue) weight.
2286
P. D. HOOPPAW AND B. L. GOODMAN
TABLE 1.—Treatments, number of light periods, hours of light and darkness per day No. of Hours Hours Experilight of of Treatmental1 periods light darkness merits design 3-1/2 20-1/2 1 1 /2L:3D2 6 18 2 1L:3D 4 20 3 1L:5D 24 0 4 24L:0D 'L = light (hours), D = darkness (hours). 2 One period of 2-1/2 hours of darkness. 3 Continuous.
TABLE 2.—Ga in, feed <'efficiency., and mortality data Treatments'
(1)
1L:3D (2)
Con1L:5D tinuous (4) (3)
494a 549 539a 528a 0.44
466b 549 535ab 517a 1.78
494a 541 551a 528a 0.89
439c 522 515b 492b 1.78
1.94a
2.07b
1.94a
2.06b
]i/2L:3D
Trait 4-wk. gain (g.) Trial 1 Trial 2 Trial 3 Combined Mortality (%) Feed (g.)/gain (g.) 1
Treatment means with different letters are significantly different (P < 0.05).
RESULTS Weight gain, feed conversion and mortality data are presented in Table 2. In Trial 1, all intermittent light treatments produced significantly greater gain (P < 0.05) than continuous light. Also, chicks in Treatment 1 and 3 gained significantly more (P < 0.05) than Treatment 2. No significant differences were observed in Trial 2. Results of Trial 3 indicated that gains in Treatments 1 and 3 were significantly greater than the continuous. Treatment 2 was not significantly different from any of the other treatments. When the three trials were combined, gains from all intermittent light treatments were significantly greater than from continuous light. There was no significant difference among intermittent light treatments. The average gains during the first and second two-week period for the light restricted groups were about four and nine percent greater than the gains under continuous light. Whether these differences would have been maintained to market weight in these groups is unknown. However, early growth is highly correlated with later growth. Feed efficiency expressed as feed consumed per unit of gain generally reflected growth rate. Treatments 1 and 3 had significantly better feed conversion than Treatment 2 or continuous light. The improved weight gains and generally better feed conversions
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on May 2, 2015
compartment was controlled by an electrical timer. The timers were synchronized so that the lights in all compartments were on at 8:00 a.m. Routine chores were performed at this time. Weight gain, feed conversion and mortality data were obtained over a four-week period. At the end of the four-week period in Trials 1 and 2, samples of six chicks per treatment were taken just prior to the lights coming on at 8:00 a.m. and also immediately at the end of the following light period (8:30 a.m. for Treatment 1 and 9:00 a.m. for Treatments 2 and 3). Chicks under continuous light were sampled at 8:00 and 9:00 a.m. After each sample had been obtained, the chicks were immediately sacrificed by breaking the neck. The crop and gizzard of each chick were individually weighed and then reweighed following the complete removal of feed and fluid from these organs. Excess moisture was
removed by blotting with paper towels. The difference between the two weights was used as a measure of feed and fluid in each organ. The crop and gizzard data were adjusted for sex differences by adding the difference between the average of all females and the average of all males to the weight obtained for each female. The data were analyzed by the analysis of variance technique as outlined by Snedecor (1956) and where applicable the multiple range technique (Duncan, 1955).
2287
INTERMITTENT LIGHT AND GROWTH
Data on contents (feed and fluid) in the crop and gizzard at the end of the dark period and also at the end of the light period, and crop and gizzard weights are given in Table 3. No significant differences between treatments were observed in weight of crop contents at the end of the dark period. The chicks on continuous light had the least quantity, although not significantly lower. Although some chicks consumed feed during the dark period, observations indicated that practically all activity ceased shortly after the beginning of the dark period and remained so throughout the entire period. At the end of the light period, differences in feed and fluid weight were significant. Crop contents of birds in Treatments 2 and 3 (1L:3D and 1L:5D) were significantly greater than the contents of chicks on continuous light. Treatment 1 (1/2L:3D) was intermediate to the continuous and Treatment 3. The increased crop contents of Treatment 2 appeared to be inconsistent with the results from the other groups.
TABLE 3.—Averages for crop and gizzard tissues and contents Treatments' Con1/2L:3D 1L:3D 1L:5D tinuous (1) (2) (3) (4)
Trait Feed and fluid in crop (g.) end of dark period 0.87 1.06 1.20 0.79 end of light period 5.02ab 14.09c 9.43b 3.57a Feed and fluid in gizzard (g-) end of dark period 10.25 7.62 7.16 9.06 end of light period 14.80 15.18 12.63 11.98 Feed and fluid in crop and gizzard (g.) end of dark period 11.12 8.68 8.36 9.85 end of light period 19.82ab 29.27c 22.05b 15.55a Crop tissue (g.) 2.85a 2.99a 2.75ab 2.51b Gizzard tissue (g.) 19.36 19.35 19.11 20.11 1 Treatment means with different letters are significantly different (P < 0.05). The increase in crop contents of chicks under the continuous light during the one hour period was significant. The initial disturbance of catching chicks from this treatment as well as the other treatments, plus the sound of active feeding from other treatments apparently stimulated greater feed consumption. This was also the normal time (8:00 a.m.) that the chicks were fed and watered. Weight of the gizzard content did not differ significantly between treatments (Table 3) either at the end of the dark period or at the end of the light (feeding) period. There was no significant differences in combined weight of the crop and gizzard contents at the end of the dark period; however, at the end of the light period, the same patterns of significance as for crop contents were observed. The increased weight of 13.69 g. (8.36 to 22.05 g. at the end of the dark and light periods, respectively) of the combined crop
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on May 2, 2015
were probably due to the reduced activity of the chicks during the dark periods which resulted in better utilization of nutrients for growth rather than for activity. Mortality was low in all treatments (Table 2) with no significant differences. One of the problems in determining the optimal length of time of light and darkness is to determine how long it takes a chick to consume enough feed for rapid growth and then how long an inactive period is necessary before the bird will actively feed when given the opportunity. Barrott and Pringle (1951) concluded that chicks ate as much as they desired within one hour and then would not actively feed for another three to four hours. Gore et al. (1969) indicated that 15 minutes of light every one or two hours were sufficient for feeding and the following 45 or 105 minutes of darkness were sufficient intervals before resumption of feeding.
2288
P. D. HOOPPAW AND B. L. GOODMAN
For chicks to consume large amounts of feed in short periods of time, it would appear that adaptation of certain digestive parts must occur. Weights of the crop and gizzard tissues are also given in Table 3. Crop weight (tissue) was significantly greater for chicks in Treatments 1 and 2 than for chicks under continuous light. Gizzard weight did not differ significantly between treatments. The amount of feed in the gizzard was similar for all treatments as measured in this experiment; thus, no apparent adaptation occurred during this experiment. However, Feigenbaum et al. (1962) reported that meal eating (feed restricted to two 1-hour periods) significantly increased weights of the crop, esophagus, and combined weight of proventriculus and gizzard as compared to "nibblers" (continuous feeders). DISCUSSION As indicated previously, inconsistent results have been reported for intermittent light treatments. However, many management factors have been variable in most reports. Factors such as form, protein and energy of the ration, age and amount of training of chick at start of project, length of project, growth rate of chicks, and amount of feeder
and watering space are among the factors which should be considered. Of those reports which gave the amount of feeder space used, only McDaniel (1972) indicated that extra feeder space was given to birds on intermittent light treatments. As the length of the light periods is reduced, more attention should be given to other management factors. The averages for the various traits measured in this experiment were very similar for the 1/2L:3D and 1L:5D treatments. Although the two treatments appear to be quite different, the total hours of light (feeding) were similar (3-1/2 and 4) due to the number of cycles (7 and 4) per day. Based on these data as well as the published reports indicated previously, there is likely an optimal range of time (total) for maximum broiler growth which needs to be spread over several periods per day. It would also appear likely that various combinations of number of cycles or periods of various lengths resulting in the same or approximately the same total time may give similar results. REFERENCES Barott, H. G., and E. M. Pringle, 1951. Effect of environment on growth and feed and water consumption of chickens. J. Nutr. 45: 265-274. Beane, W. L., P. B. Siegel and H. S. Siegel, 1962. The effect of light on body weight and feed conversion of broilers. Poultry Sci. 41: 1350-1351. Beane, W. L., P. B. Siegel and H. S. Siegel, 1965. Light environment as a factor in growth and feed efficiency in meat-type chickens. Poultry Sci. 44: 1009-1012. Buckland, R. B., 1975. The effect of intermittent lighting programmes on the production of market chickens and turkeys. World's Poultry Sci. J. 31: 262-270. Cain, J. R., 1973. Effect of intermittent light schedules on broiler performance. Poultry Sci. 52: 2006. Centa,D.,D. P. FosheeandJ. R. Howes, 1969. Control of feeding behavior in poultry. Psychological Reports, 24: 153-154. Cherry, P., and M. W. Barwick, 1962. The effect of light on broiler growth. II. Light patterns. Brit. Poultry Sci. 3: 41-50. Clegg, R. E., and P. E. Sanford, 1951. The influence
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on May 2, 2015
and gizzard contents for Treatment 3 was considerably greater, although not significant, when compared to the increase of 8.70 g. for Treatment 1; however, the total increase in content weight over a 24-hour period (as a measure of feed and water consumption) was approximately equal (55 vs. 61 g.) when the total number of feeding periods (4 vs. 7) in each treatment was considered. Whether the chicks consumed approximately the same amount of feed and water during each light period was not determined in these trials. Treatment 2 was inconsistent with the results of Treatments 1 and 3 in all data pertaining to weights of the crop and gizzard contents.
INTERMITTENT LIGHT AND GROWTH
Gore, W. E., D. P. Foshee and J. R. Howes, 1969. Effect of background illumination and light-dark period on weight gain in broilers. Poultry Sci. 48: 1282-1287. Marr, J. E., D. E. Greene and J. L. Williamson, 1971. Photoperiods and broiler performance. Poultry Sci. 50: 1601-1602. McDaniel, G. R., 1972. The effect of continuous light versus intermittent light on the growth rate of broilers. Poultry Sci. 52: 2006. Shutze, J. V., L. S. Jensen and W. E. Matson, 1959. Effect of lighting regimes on growth and subsequent egg production of chickens. Poultry Sci. 38: 1246. Snedecor, G. W., 1956. Statistical Methods. The Iowa State College Press, Ames, Iowa.
Effects of 1,3-Butanediol and 1,2-Propanediol on Growth, Blood Metabolites, and Liver Glycogen in Broiler Chickens B . EMMANUEL
Department of Animal Biology, School of Veterinary Medicine, Pahlavi Univeristy, Shiraz, Iran (Received for publication March 2, 1976)
ABSTRACT Control diets, and diets containing 4% 1,3-butanediol (BD), 8% BD, 4% 1,2-propanediol (PD) and 8% PD were offered ad libitum to broilers from 1 to 28 days of age. Body weight gain and feed intake were recorded, and plasma metabolites and liver glycogen were measured. When compared to the control diet, the synthetic compounds depressed (P < 0.01) growth at the 4% level, but the effect was more pronounced (P < 0.01) at the 8% level. The test compounds had no effect (P < 0.05) on the efficiency of feed utilization. Four percent BD elevated (P < 0.01) plasma P-hydroxybutyrate and acetoacetate concentrations, and the ratio of p-hydroxybutyrate to acetoacetate. The influence was more pronounced at the 8% level; PD did not affect (P > 0.05) ketone body concentrations. Neither BD, nor PD caused changes (P > 0.05) in plasma glucose, free fatty acids, cholesterol, or liver glycogen. Results are discussed with reference to feeding these compounds to monogastric and ruminant animals. POULTRY SCIENCE 55: 2289-2294, 1976
INTRODUCTION
T
H E glycols 1,3-butanediol (BD) and 1,2propanediol (PD) are nontoxic (Bornmann, 1955) and relatively energy rich synthetic compounds, which in recent years have been used as a source of dietary energy in animal nutrition. The metabolizable energy of BD was found to be 6.6 kcal./gm. for chickens (Davenport and Griffith, 1969) and 6.0 kcal./gm. for rats (Miller and Dymsza, 1967). The effect of BD on growth has been
studied in monogastric animals (Stoewsand et al., 1966), and in ruminants (Bonner et al., 1972). Also, its influence has been investigated on tissue metabolites (Mehlman etal., 1971b; Tate et al., 1971), and on enzyme activity (Mehlman et al., 1972; Romsos et al., 1974b) in the rat, and on blood metabolites in ruminants (Emmanuel and Nahapetian, 1975). The antiketogenic action of PD in ruminants has been well established (Emery et al., 1964). The effect of PD on the perform-
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of intermittent periods of light and dark on the rate of growth of chicks. Poultry Sci. 30: 760-762. Dorminey, R. W., 1971. Broiler performance as affected by varying light periods and light intensities. Poultry Sci. 50: 1572. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Feigenbaum, A. S., H. Fisher and A. S. Weiss, 1962. Effect of "meal eating" vs "nibbling" and body composition and digestive organ weight of normal and cropectomized chickens. Am J. Clin. 11: 312316. Foshee, D. P., D. M. Centa, G. R. McDaniel and C. A. Rollo, 1970. Diurnal activity patterns of broilers in a controlled environment. Poultry Sci. 49: 1514-1518.
2289
HOOPPAW 1 AND B . L .
GOODMAN
Animal Industries Department, Southern Illinois University, Carbondale, Illinois 62901 (Received for publication March 2, 1976)
POULTRY SCIENCE 55: 2285-2289,
I
NTERMITTENT light with several cycles or periods of light and darkness per day has given inconsistent results when contrasted with continuous light or with one period of light and one period of darkness per day. Favorable results have been reported by Clegg and Sanford (1951), Barrott and Pringle (1951), Centa et al. (1969), Marr et al. (1971), McDaniel (1972), and Cain (1973). Reports indicating only equal or less desirable results include Shutze et al. (1959), Beane etal. (1962, 1965), Cherry and Barwick (1962), Gore et al. (1969), Foshee et al. (1970) and Dorminey (1971). Published reports on the influence of intermittent lighting on both turkeys and market chickens have been reviewed by Buckland (1975). The potential value of the use of intermittent light to the industry indicates that additional work is needed. PROCEDURE Chicks from the Silver Oklabar growthselected strain were placed in a battery
1. Present address: LandO'Lakes, Inc., New Richland, Minnesota 56072.
1976
brooder with continuous light for six days to allow adjustment to feeders and waterers. All chicks were then sorted in weight groups, and then were wingbanded and distributed at random to each treatment. The difference in average weight per chick per treatment was less than one gram. Three trials with 300 straight-run chicks per trial were conducted. The experimental design (Table 1) involved three light restrictions of 1 /2L:3D (one-half hour of light and three hours of darkness) 1L:3D, and 1L:5D as compared to continuous light with total number of hours of light (feeding time) of 3-1 / 2 , 6, 4 and 24 hours, respectively. The trials were conducted in a room which partitioned into four 1.76 x 2.21 in. compartments. Each chick was given approximately 0.06 m.2 of space in the battery and approximately 4.1 cm. of feeding and watering space. Two 25-watt incandescent bulbs were vertically spaced to provide 32 to 54 lux at the edge of the feeders and waterers of the battery brooder. Although some light seepage occurred, observations indicated little, if any, chick activity until the lights were on in that compartment. The light interval within each
2285
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on May 2, 2015
ABSTRACT Treatments of 1/2L:3D, (1/2 hour light and 3 hours darkness), 1L:3D, 1L:5D lighting cycles and continuous light were used in three trials to grow 900 straight-run chicks from 7 to 35 days of age. Chicks on intermittent light had significantly (P < 0.05) greater gains than those on continuous light. There was no significant difference among treatments with intermittent light. Feed conversion for 1/2L:3D and 1L:5D treatments was significantly better than for the other two treatments. Weights of crop and gizzard contents at the end of dark period (8:00 a.m.) were not significantly different among treatments; however, at the end of the light (feeding) period, at 8:30 or 9:00 a.m., chicks on intermittent light generally had significantly more feed and fluid in the crop, but not in the gizzard, than chicks on continuous light. The crop (tissue) was generally significantly heavier in chicks from the intermittent light treatments. There was no significant difference among treatments for gizzard (tissue) weight.
2286
P. D. HOOPPAW AND B. L. GOODMAN
TABLE 1.—Treatments, number of light periods, hours of light and darkness per day No. of Hours Hours Experilight of of Treatmental1 periods light darkness merits design 3-1/2 20-1/2 1 1 /2L:3D2 6 18 2 1L:3D 4 20 3 1L:5D 24 0 4 24L:0D 'L = light (hours), D = darkness (hours). 2 One period of 2-1/2 hours of darkness. 3 Continuous.
TABLE 2.—Ga in, feed <'efficiency., and mortality data Treatments'
(1)
1L:3D (2)
Con1L:5D tinuous (4) (3)
494a 549 539a 528a 0.44
466b 549 535ab 517a 1.78
494a 541 551a 528a 0.89
439c 522 515b 492b 1.78
1.94a
2.07b
1.94a
2.06b
]i/2L:3D
Trait 4-wk. gain (g.) Trial 1 Trial 2 Trial 3 Combined Mortality (%) Feed (g.)/gain (g.) 1
Treatment means with different letters are significantly different (P < 0.05).
RESULTS Weight gain, feed conversion and mortality data are presented in Table 2. In Trial 1, all intermittent light treatments produced significantly greater gain (P < 0.05) than continuous light. Also, chicks in Treatment 1 and 3 gained significantly more (P < 0.05) than Treatment 2. No significant differences were observed in Trial 2. Results of Trial 3 indicated that gains in Treatments 1 and 3 were significantly greater than the continuous. Treatment 2 was not significantly different from any of the other treatments. When the three trials were combined, gains from all intermittent light treatments were significantly greater than from continuous light. There was no significant difference among intermittent light treatments. The average gains during the first and second two-week period for the light restricted groups were about four and nine percent greater than the gains under continuous light. Whether these differences would have been maintained to market weight in these groups is unknown. However, early growth is highly correlated with later growth. Feed efficiency expressed as feed consumed per unit of gain generally reflected growth rate. Treatments 1 and 3 had significantly better feed conversion than Treatment 2 or continuous light. The improved weight gains and generally better feed conversions
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on May 2, 2015
compartment was controlled by an electrical timer. The timers were synchronized so that the lights in all compartments were on at 8:00 a.m. Routine chores were performed at this time. Weight gain, feed conversion and mortality data were obtained over a four-week period. At the end of the four-week period in Trials 1 and 2, samples of six chicks per treatment were taken just prior to the lights coming on at 8:00 a.m. and also immediately at the end of the following light period (8:30 a.m. for Treatment 1 and 9:00 a.m. for Treatments 2 and 3). Chicks under continuous light were sampled at 8:00 and 9:00 a.m. After each sample had been obtained, the chicks were immediately sacrificed by breaking the neck. The crop and gizzard of each chick were individually weighed and then reweighed following the complete removal of feed and fluid from these organs. Excess moisture was
removed by blotting with paper towels. The difference between the two weights was used as a measure of feed and fluid in each organ. The crop and gizzard data were adjusted for sex differences by adding the difference between the average of all females and the average of all males to the weight obtained for each female. The data were analyzed by the analysis of variance technique as outlined by Snedecor (1956) and where applicable the multiple range technique (Duncan, 1955).
2287
INTERMITTENT LIGHT AND GROWTH
Data on contents (feed and fluid) in the crop and gizzard at the end of the dark period and also at the end of the light period, and crop and gizzard weights are given in Table 3. No significant differences between treatments were observed in weight of crop contents at the end of the dark period. The chicks on continuous light had the least quantity, although not significantly lower. Although some chicks consumed feed during the dark period, observations indicated that practically all activity ceased shortly after the beginning of the dark period and remained so throughout the entire period. At the end of the light period, differences in feed and fluid weight were significant. Crop contents of birds in Treatments 2 and 3 (1L:3D and 1L:5D) were significantly greater than the contents of chicks on continuous light. Treatment 1 (1/2L:3D) was intermediate to the continuous and Treatment 3. The increased crop contents of Treatment 2 appeared to be inconsistent with the results from the other groups.
TABLE 3.—Averages for crop and gizzard tissues and contents Treatments' Con1/2L:3D 1L:3D 1L:5D tinuous (1) (2) (3) (4)
Trait Feed and fluid in crop (g.) end of dark period 0.87 1.06 1.20 0.79 end of light period 5.02ab 14.09c 9.43b 3.57a Feed and fluid in gizzard (g-) end of dark period 10.25 7.62 7.16 9.06 end of light period 14.80 15.18 12.63 11.98 Feed and fluid in crop and gizzard (g.) end of dark period 11.12 8.68 8.36 9.85 end of light period 19.82ab 29.27c 22.05b 15.55a Crop tissue (g.) 2.85a 2.99a 2.75ab 2.51b Gizzard tissue (g.) 19.36 19.35 19.11 20.11 1 Treatment means with different letters are significantly different (P < 0.05). The increase in crop contents of chicks under the continuous light during the one hour period was significant. The initial disturbance of catching chicks from this treatment as well as the other treatments, plus the sound of active feeding from other treatments apparently stimulated greater feed consumption. This was also the normal time (8:00 a.m.) that the chicks were fed and watered. Weight of the gizzard content did not differ significantly between treatments (Table 3) either at the end of the dark period or at the end of the light (feeding) period. There was no significant differences in combined weight of the crop and gizzard contents at the end of the dark period; however, at the end of the light period, the same patterns of significance as for crop contents were observed. The increased weight of 13.69 g. (8.36 to 22.05 g. at the end of the dark and light periods, respectively) of the combined crop
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on May 2, 2015
were probably due to the reduced activity of the chicks during the dark periods which resulted in better utilization of nutrients for growth rather than for activity. Mortality was low in all treatments (Table 2) with no significant differences. One of the problems in determining the optimal length of time of light and darkness is to determine how long it takes a chick to consume enough feed for rapid growth and then how long an inactive period is necessary before the bird will actively feed when given the opportunity. Barrott and Pringle (1951) concluded that chicks ate as much as they desired within one hour and then would not actively feed for another three to four hours. Gore et al. (1969) indicated that 15 minutes of light every one or two hours were sufficient for feeding and the following 45 or 105 minutes of darkness were sufficient intervals before resumption of feeding.
2288
P. D. HOOPPAW AND B. L. GOODMAN
For chicks to consume large amounts of feed in short periods of time, it would appear that adaptation of certain digestive parts must occur. Weights of the crop and gizzard tissues are also given in Table 3. Crop weight (tissue) was significantly greater for chicks in Treatments 1 and 2 than for chicks under continuous light. Gizzard weight did not differ significantly between treatments. The amount of feed in the gizzard was similar for all treatments as measured in this experiment; thus, no apparent adaptation occurred during this experiment. However, Feigenbaum et al. (1962) reported that meal eating (feed restricted to two 1-hour periods) significantly increased weights of the crop, esophagus, and combined weight of proventriculus and gizzard as compared to "nibblers" (continuous feeders). DISCUSSION As indicated previously, inconsistent results have been reported for intermittent light treatments. However, many management factors have been variable in most reports. Factors such as form, protein and energy of the ration, age and amount of training of chick at start of project, length of project, growth rate of chicks, and amount of feeder
and watering space are among the factors which should be considered. Of those reports which gave the amount of feeder space used, only McDaniel (1972) indicated that extra feeder space was given to birds on intermittent light treatments. As the length of the light periods is reduced, more attention should be given to other management factors. The averages for the various traits measured in this experiment were very similar for the 1/2L:3D and 1L:5D treatments. Although the two treatments appear to be quite different, the total hours of light (feeding) were similar (3-1/2 and 4) due to the number of cycles (7 and 4) per day. Based on these data as well as the published reports indicated previously, there is likely an optimal range of time (total) for maximum broiler growth which needs to be spread over several periods per day. It would also appear likely that various combinations of number of cycles or periods of various lengths resulting in the same or approximately the same total time may give similar results. REFERENCES Barott, H. G., and E. M. Pringle, 1951. Effect of environment on growth and feed and water consumption of chickens. J. Nutr. 45: 265-274. Beane, W. L., P. B. Siegel and H. S. Siegel, 1962. The effect of light on body weight and feed conversion of broilers. Poultry Sci. 41: 1350-1351. Beane, W. L., P. B. Siegel and H. S. Siegel, 1965. Light environment as a factor in growth and feed efficiency in meat-type chickens. Poultry Sci. 44: 1009-1012. Buckland, R. B., 1975. The effect of intermittent lighting programmes on the production of market chickens and turkeys. World's Poultry Sci. J. 31: 262-270. Cain, J. R., 1973. Effect of intermittent light schedules on broiler performance. Poultry Sci. 52: 2006. Centa,D.,D. P. FosheeandJ. R. Howes, 1969. Control of feeding behavior in poultry. Psychological Reports, 24: 153-154. Cherry, P., and M. W. Barwick, 1962. The effect of light on broiler growth. II. Light patterns. Brit. Poultry Sci. 3: 41-50. Clegg, R. E., and P. E. Sanford, 1951. The influence
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on May 2, 2015
and gizzard contents for Treatment 3 was considerably greater, although not significant, when compared to the increase of 8.70 g. for Treatment 1; however, the total increase in content weight over a 24-hour period (as a measure of feed and water consumption) was approximately equal (55 vs. 61 g.) when the total number of feeding periods (4 vs. 7) in each treatment was considered. Whether the chicks consumed approximately the same amount of feed and water during each light period was not determined in these trials. Treatment 2 was inconsistent with the results of Treatments 1 and 3 in all data pertaining to weights of the crop and gizzard contents.
INTERMITTENT LIGHT AND GROWTH
Gore, W. E., D. P. Foshee and J. R. Howes, 1969. Effect of background illumination and light-dark period on weight gain in broilers. Poultry Sci. 48: 1282-1287. Marr, J. E., D. E. Greene and J. L. Williamson, 1971. Photoperiods and broiler performance. Poultry Sci. 50: 1601-1602. McDaniel, G. R., 1972. The effect of continuous light versus intermittent light on the growth rate of broilers. Poultry Sci. 52: 2006. Shutze, J. V., L. S. Jensen and W. E. Matson, 1959. Effect of lighting regimes on growth and subsequent egg production of chickens. Poultry Sci. 38: 1246. Snedecor, G. W., 1956. Statistical Methods. The Iowa State College Press, Ames, Iowa.
Effects of 1,3-Butanediol and 1,2-Propanediol on Growth, Blood Metabolites, and Liver Glycogen in Broiler Chickens B . EMMANUEL
Department of Animal Biology, School of Veterinary Medicine, Pahlavi Univeristy, Shiraz, Iran (Received for publication March 2, 1976)
ABSTRACT Control diets, and diets containing 4% 1,3-butanediol (BD), 8% BD, 4% 1,2-propanediol (PD) and 8% PD were offered ad libitum to broilers from 1 to 28 days of age. Body weight gain and feed intake were recorded, and plasma metabolites and liver glycogen were measured. When compared to the control diet, the synthetic compounds depressed (P < 0.01) growth at the 4% level, but the effect was more pronounced (P < 0.01) at the 8% level. The test compounds had no effect (P < 0.05) on the efficiency of feed utilization. Four percent BD elevated (P < 0.01) plasma P-hydroxybutyrate and acetoacetate concentrations, and the ratio of p-hydroxybutyrate to acetoacetate. The influence was more pronounced at the 8% level; PD did not affect (P > 0.05) ketone body concentrations. Neither BD, nor PD caused changes (P > 0.05) in plasma glucose, free fatty acids, cholesterol, or liver glycogen. Results are discussed with reference to feeding these compounds to monogastric and ruminant animals. POULTRY SCIENCE 55: 2289-2294, 1976
INTRODUCTION
T
H E glycols 1,3-butanediol (BD) and 1,2propanediol (PD) are nontoxic (Bornmann, 1955) and relatively energy rich synthetic compounds, which in recent years have been used as a source of dietary energy in animal nutrition. The metabolizable energy of BD was found to be 6.6 kcal./gm. for chickens (Davenport and Griffith, 1969) and 6.0 kcal./gm. for rats (Miller and Dymsza, 1967). The effect of BD on growth has been
studied in monogastric animals (Stoewsand et al., 1966), and in ruminants (Bonner et al., 1972). Also, its influence has been investigated on tissue metabolites (Mehlman etal., 1971b; Tate et al., 1971), and on enzyme activity (Mehlman et al., 1972; Romsos et al., 1974b) in the rat, and on blood metabolites in ruminants (Emmanuel and Nahapetian, 1975). The antiketogenic action of PD in ruminants has been well established (Emery et al., 1964). The effect of PD on the perform-
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of intermittent periods of light and dark on the rate of growth of chicks. Poultry Sci. 30: 760-762. Dorminey, R. W., 1971. Broiler performance as affected by varying light periods and light intensities. Poultry Sci. 50: 1572. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Feigenbaum, A. S., H. Fisher and A. S. Weiss, 1962. Effect of "meal eating" vs "nibbling" and body composition and digestive organ weight of normal and cropectomized chickens. Am J. Clin. 11: 312316. Foshee, D. P., D. M. Centa, G. R. McDaniel and C. A. Rollo, 1970. Diurnal activity patterns of broilers in a controlled environment. Poultry Sci. 49: 1514-1518.
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