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Influence of Litter Type and Size on Broiler Performance
Influence of Litter Type and Size on Broiler Performance. 1. Factors Affecting Litter Consumption1 G. W. MALONE 2 and G. W. CHALOUPKA3 University of Delaware, Substation Division, Georgetown, Delaware 19947 W. W. SAYLOR Department of Animal Science and Agricultural Biochemistry, University of Delaware, Newark, Delaware 19711 (Received for publication September 15, 1982)
1983 Poultry Science 62:1741-1746 INTRODUCTION
Previous litter research has often demonstrated that litter type has a significant effect on broiler performance. In many cases, these differences have not been explained. In studies with various types of recycled paper products, Malone and Chaloupka (1981, 1982) and Malone et al. (1982, 1983) have found that broilers reared on paper base litters generally had significantly improved body weights and often improved feed efficiency compared to broilers grown on wood shavings or sawdust. In studies with composted municipal garbage (recycled paper base product) as litter, Malone et al. (1983) observed that broilers grown on wood shavings had larger gizzards than broilers reared on paper. Subsequent studies with
1 Published with the approval of the Director of the Delaware Agricultural Experiment Station as Miscellaneous Paper No. 991, Contribution No. 71 of the Department of Animal Science and Agricultural Biochemistry, University of Delaware, Newark, DE 19711. 2 Agricultural Experiment Station. 3 Cooperative Extension Service.
shredded newspaper litter confirmed that gizzard weights were decreased in broilers raised on the paper base litter. Malone and Chaloupka (1982) reported that broilers placed solely on shredded newspaper at an early age had fewer foreign particles in the gizzard and had a lower incidence of coccidial lesions compared to broilers placed on sawdust. From these observations, it would appear that litter consumption may have some role in the response of broilers to type of litter. Caldwell and McDaniel (1982) reported a significant increase in growth and less foreign material in the gizzard of broilers reared on a suspended metal floor than those reared on litter. Gizzard weights were also lower in cage-reared broilers compared to those grown on litter (Deaton et al., 1973). It was the purpose of this investigation to determine the influence of broiler age, litter type, and particle size on litter consumption. MATERIALS AND METHODS
In each of two battery trials, 240 Hubbard x Hubbard male chicks were wing banded and placed in electrically heated starter battery cages. Four pens of 10 chicks each were used
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ABSTRACT The influence of broiler age, litter type, and particle size was studied to determine their effects on litter consumption in two battery trials involving 240 broilers each. In Experiment 1, broilers were provided no litter, wood chips, sawdust, wood fibers, processed newspaper, or newspaper fibers ad libitum from 1 to 49 days of age. In Experiment 2, sawdust was provided free choice daily as the only litter source to broilers starting at 1, 7, or 14 days of age until the 21st day. Broilers consumed significantly greater quantities of sawdust and wood fibers than other litter types and sizes. The consumption rate of all materials decreased after 21 days of age. In Experiment 2, consumption of sawdust was highest when provided any time up to 14 days of age. Based on litter intake and the presence of litter in the gizzards, the data revealed significantly greater consumption of sawdust and high concentrations of sawdust in the gizzard; broilers provided wood fibers also had high intakes but low levels in the gizzard; consumption of wood chips was low but the particles were present in the gizzard; and consumption of newspaper based litter was low and little foreign material was found in the gizzard. (Key words: litter, particle size, wood products, newspaper fiber, broiler consumption, growth)
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The influence of broiler age on litter consumption was determined in Experiment 2 using the same facilities as the first study. Sawdust was fed ad libitum for the following time periods: 1 to 21 days of age, 7 to 21 days, 14 to 21 days. A control group was allowed no access to litter. Nonscreened white oak sawdust with approximately 85% of the particles less than .2 cm diameter was obtained from a single
tree directly from a local sawmill. At 7, 14, and 21 days, body weight and feed and litter consumption were determined. Gizzard and liver weights and gizzard litter score were obtained for all broilers at 21 days of age. The gizzard litter score was a subjective score based on a visual observation of gizzard contents. Scores of zero, one, two and three represent no litter, less than 30%, 30 to 60%, and greater than 60% litter in the gizzard contents, respectively. All data were subjected to analysis of variance, and treatments were compared using Duncan's multiple range test when the F-value for treatment from the analysis of variance was below 5% significance (Steel and Torrie, 1960). All percentage data were transformed using arcsin prior to statistical analysis and converted back to the original base following the multiple range test. RESULTS AND DISCUSSION When expressing the litter intake as the percent of total intake of both feed and litter on a weight basis, chicks consumed significantly greater quantities of sawdust and wood fibers between 8 to 21 and 22 to 49 days of age (Table 1). During the first week of age, up to 6.35% of the diet was litter when provided free choice in the form of wood fibers. Consumption of both forms of newspaper and wood chips were low throughout the study, suggesting both type and particle size of litter affects intake. At an early age, the large size of wood chips alone prohibited eating this form of litter. The newspaper based product would appear to be less palatable, perhaps due to its low density and irregular particle size. Both wood fibers and sawdust, however, had texture and density similar to that of the feed. In all treatments, the intake generally decreased after 21 days of age. In the second experiment, chicks provided sawdust at 1 or 7 days of age had litter intakes higher than those having access starting at 14 days, indicating an age-related effect. For those chicks provided sawdust at 1 day, the level of intake remained constant for 2 weeks, then declined. Within each treatment, certain pens had up to four times the litter intake over companion pens, indicating there were apparently other unknown stimuli to encourage litter consumption. Pens with high initial intakes generally continued to have elevated intake levels throughout the study. Hogan-Warburg
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for each treatment in Experiment 1 and six pens of 10 chicks were used in the second experiment. Of the total 62 cm of feeder space per pen, a solid partition was installed to provide 25% of the trough area for the litter treatments. Water and a commercial type diet were provided ad libitum in both studies. A starter crumble diet containing 24.2% protein and 3186 kcal ME/kg of feed was fed from 1 to 21 days and a finisher pellet diet with 21.0% protein and 3351 kcal/kg was fed from 22 to 49 days. In Experiment 1, the effect of litter particle size and type of litter was evaluated using the following treatments: wood chips (.6 to 1.3 cm wide by 1.3 to 2.5 cm long), sawdust and processed newspaper (.2 to .6 cm diameter), wood fibers and processed newspaper fibers (less than .2 cm diameter), and a control with no material provided. Each litter material was placed in the partitioned area of the trough when the birds were 1 day of age. The wood chips and sawdust were obtained from one Quercus alba (white oak) tree at a local sawmill and the processed newspaper was from the source and process described by Malone et al. (1982). A subsample of wood chips and processed newspaper were ground to obtain the fiber treatments. All treatments were sieved to ensure the desired particle size. From each pen in Experiment 1, 2 birds at 7 and 21 days and the remaining birds at 49 days were necropsied for litter content in the gizzard and for gizzard and liver weights. Gizzards were cleaned, peeled, and trimmed of fat prior to weighing. A fecal sample was collected for a 24-hr period prior to each necropsy date, dried, ground, and analyzed for acid detergent fiber (ADF) (Van Soest, 1963) and neutral detergent fiber (NDF) (Van Soest and Wine, 1967). At 7, 21, and 49 days, all birds were weighed, and feed and litter consumption were determined. At 21 days, all broilers were transferred to a finishing battery unit to allow for increased floor and head space (feeder trough length and design were the same as before).
LITTER CONSUMPTION
As shown in Table 2, body weights generally decreased when litter consumption was above 4% of the diet. With wood fibers in Experiment 1 or the nonscreened sawdust from Experiment 2, there was a consistent effect of high levels of intake on subsequent body weights. In the first experiment, when the male broilers were grown to market age in battery cages, there was high variability in 49-day body weights between individuals and between pens within the same treatment. Part of this variation was associated
with 11% incidence of leg disorders, which affected the weights of all treatments. The variability in weights may account for no treatment effect at 49 days even though the spread in treatment means was wide. In Experiment 2, sawdust provided to broilers after 14 days of age was not detrimental to 21 day weights. Feed efficiency and mortality were not significantly affected by treatment in either study. Based on a subjective score of the amount of litter in the gizzard, birds receiving sawdust had the highest concentration of litter in the gizzard at all ages (Table 3). Those given wood fibers had significant quantities initially (probably associated with high intakes), but the amount of fibers depleted more rapidly than sawdust, possibly as a result of increased passage through the digestive system. Because wood chips would require increased gizzard activity to reduce the particle size, this material may have accumulated in the gizzard, although consumption rates were generally low. Because these battery studies with wood-based products do not simulate floor pen situations, the validity of these results may be questioned. However, in two previous trials in which gizzard scores were recorded by the same person, Malone and Chaloupka (1982) found litter (sawdust) in the gizzards of floor pen birds equal to and, in many cases greater
TABLE 1. Broiler Utter intake as influenced by broiler age, litter size, and type Litter • intake 1
Experiment no.
Litter treatment 2
1-7 days
8 - 2 1 days
1
Wood chips Sawdust Wood fibers Processed newspaper Newspaper fibers No litter
.32C 2.31 b 6.35a .39 b c .15 c 0
,14b 3.08 a 4.82a .49b .29 b 0
Ob .95 a 1.28 a ,10b .04b 0
1—7 days
8 - 1 4 days
1 5 - 2 1 days
4.03 0 0 0
4.52 a 5.23 a 0 0
2.90b 5.18 a 1.9lb 0
2 2 - 4 9 days
V'O)
Sawdust, 1 day Sawdust, 7 days Sawdust, 14 days No sawdust
2
' ' Within each experiment, litter intake means in the same column having different superscripts are significantly different (P<.05). 1 2
Litter intake is expressed as percent of total dietary consumption of both feed and litter on a weight basis.
Litter treatments in Experiment 1 were provided ad libitum starting at day of age. In Experiment 2, sawdust was provided from the day stated until the termination at 21 days of age.
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and Hogan (1981) reported that ingestion of sand varies widely among individuals and the chick's appetite for food gradually develops as a result of an association between stimuli from food and positive long-term aftereffects of food ingestion. Preliminary reports by Malone and Chaloupka (1982) and Caldwell and McDaniel (1982) also suggest that litter eating may be a learned behavioral trait developed at an early age. Based on those chicks having access to sawdust at day of age (Experiment 2), litter consumption peaked within 14 days postexposure, then declined. There appeared to be little desire to eat litter if it was provided for the first time at 14 days of age. However, Bootwalla et al. (1982) recently found that breeder hens reared on wire floors and provided litter in the feeders at 52 weeks of age consumed 18.3 g litter/bird/day.
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TABLE 2. Broiler body weight as influenced by age ofb roller when exposed to various litter types and sizes Experiment no.
Body weight
Litter treatment 1
7 days
Wood chips Sawdust Wood fibers Processed newspaper Newspaper fibers No litter
116.7b 126.5 a 109.5 b 117.4b 119.8 b 121.2*b
Sawdust, 1 day Sawdust, 7 days Sawdust, 14 days No sawdust
117.3a 121.9a 125. l a 120.5a
14 days
21 days
49 days
565.5a 553.7a 512.5b 561.5a 564.2a 552.7a
2264 a 2221 a 2164 a 2236 a 2241 a 2184 a
(g)
517.lb 516.0b 549.8a 546.2a
' ' Within each experiment, body weight means in the same column having different superscripts are significantly different (P<.05). 1 Litter treatments in Experiment 1 were provided ad libitum starting at day of age. In Experiment 2, sawdust was provided from the day stated until the termination at 21 days of age.
than, the levels observed in this study. Consumption and litter content of the gizzard of broilers having access to newspaper were lower than for broilers provided sawdust or wood fibers. Because the fiber in the feed closely resembles wood and newspaper fibers in texture, the gizzard score of the no litter treatment
probably represents dietary fiber rather than litter in Experiment 1. The distinction between litter (sawdust) and feed fiber in the gizzard contents was clear in the second experiment. The size of the gizzard is determined by the muscular activity of the organ to comminute the ingested particles (Branion, 1963); there-
TABLE 3. Broiler gizzard litter score as influer ced by age of broiler exposure to various litter types and sizes Experiment no.
Gizzard litter score1
Litter treatment 2
7 days
21 days
Wood chips Sawdust Wood fibers Processed newspaper Newspaper fibers No litter
.25 b 2.25 a 2.00 a .75 b .75 b .25 b
.13b 2.50 a .38 b .13b .13b .13b
Sawdust, 1 day Sawdust, 7 days Sawdust, 14 days No sawdust
49 days 90b 75 a 62bc 3 3c 17 c 21 c
1.90b 2.28 a 1.62c Od
' ' ' Within each experiment, gizzard litter score means in the same column having different superscripts are significantly different (P<.05). 1 Subjective score of 0 to 3 based on the amount of litter in the gizzard. Values represent: 0, no litter; 1, less than 30%; 2, 30 to 60%; and 3, greater than 60% litter making up the total gizzard content. 2 Litter treatments in Experiment 1 were provided ad libitum starting at day of age. In Experiment 2, sawdust was provided from the day stated until the termination at 21 days of age.
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267.4C 275.5bc 295.0a 286.0ab
LITTER CONSUMPTION
In summary, wood-base products have been a standard and highly desirable litter material for most broiler producing areas. As these conventional sources increase in price and decrease in availability, alternative materials such as newspaper based products are being tested experimentally and commercially with a general improvement in broiler performance in many cases. Based on the results of this and other studies, part of the difference in performance may be associated with litter consumption of the wood based litter products. Chicks with access to wood fibers or nonscreened sawdust during the first 2 weeks of age may consume more than 4% of their diet as litter which apparently has a detrimental effect on subsequent body weight. Crawford et al. (1980) suggest that consumption of shavings may be associated with distance of feed and water from the chicks' heat source. As the distance increased, shavings reared broilers had higher mortality from starve-outs and decreased body weights compared to those placed on chopped straw. Recent new management practices, such as confinement brooding with inadequate feeder space or room temperatures, increased disease stress from high density brooding and the increased appetite of today's broiler stocks may contribute to the problem. Because the sawdust has textural and visual properties
TABLE 4. Broiler gizzard weight as influenced by age of broiler exposure to various litter types and sizes Gizzard weight 1
Experiment no.
Litter treatment2
7 days
21 days
4 9 days
1
Wood chips Sawdust Wood fibers Processed newspaper Newspaper fibers No litter
4.64C 5.19a 5.43a 5.08ab 4.70bc 4.60C
2.35abc a
1.36 a 1.40 a 1.35 a 1.24b 1.24b 1.3 l a b
2
Sawdust, 1 day Sawdust, 7 days Sawdust, 14 days No sawdust
2.58 2.46ab 2.16c 2.20DC 2.32abc 2.92a 3.02a 2.58b 2.29c
' ' Within each experiment, gizzard weight means in the same column having different superscripts are significantly different (P<.05). 1
Gizzard weight is expressed as percent of live body weight. Litter treatments in Experiment 1 were provided ad libitum starting at day of age. In Experiment 2, sawdust was provided from the day stated until the termination at 21 days of age. 2
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fore, one would expect greater gizzard weights in treatments with high litter intakes. Treatment differences in gizzard weights (Table 4) followed a pattern very similar to that shown by gizzard litter scores. High consumption of wood fibers and sawdust at an early age increased gizzard weight over the control, newspaper fibers, and wood chips at 7 days, whereas both particle size and total intake appeared to influence organ size at subsequent ages. For broilers given litter in the form of sawdust, the size of the gizzard may be a sensitive indicator of litter consumption. None of the treatments had a significant effect on liver weight. When the fecal fiber data from 1 to 21 days of age were pooled, broilers fed wood fibers had significantly higher excretion of ADF than all other treatments (Table 5). The excretion of NDF for the first 21 days was also significantly higher with both sawdust and wood fiber than other litter types. Fecal ADF and NDF values at 49 days and hemicellulose values at all ages were similar between treatments. These fiber values tend to parallel litter intake in that both wood fiber and sawdust had the highest intake and excretion of the fiber. Part of the variability within treatments in this study may have been associated with individual differences in fiber digestibility within strain as suggested by Hollister and Nakaue (1982).
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MALONE ET AL. TABLE 5. Fiber content of broiler feces as influenced by litter size and type 1-21 days'
Experiment no.
Litter treatment 2
ADF
1
Wood chips Sawdust Wood fibers Processed newspaper Newspaper fibers No litter
19.40b 21.90b 25.74* 20.76° 19.73° 21.17b
(73.7) (74.0) (77.2) (78.3)
22- -49 days 1
NDF
ADF
NDF
34.92 b 41.43* (87.9) 41.45 a (89.9) 37.10b (94.0) 36.56b (94.0) 36.54 b
21.02* 18.44* 18.52* 21.43* 15.73* 17.10*
35.01* 33.14a 35.64* 33.82* 34.05* 35.36*
ab ' Within each column, fiber values having different superscripts are significantly different (P-C05).
2
Litter treatments in Experiment 1 were provided ad libitum starting at day of age.
similar to feed, management factors that minimize litter consumption at an early age should prove beneficial. REFERENCES Bootwalla, S. M„ R. H. Harms, and H. R. Wilson, 1982. The influence of litter vs. wire floor on the weight and specific gravity of eggs from broiler breeder hens. Poultry Sci. 61:1421-1422. (Abstr). Branion, H. D., 1963. An abnormality of the proventriculus and gizzard of chicks. Poultry Sci. 42:736-743. Caldwell, D. K., and G. R. McDaniel, 1982. Performance of broilers reared on a plastic-coated metal floor and in a conventional environment. Poultry Sci. 61:1371. (Abstr.) Crawford, R. D., J. B. O'Neil, and T. A. Scott, 1980. Canadian research includes chick survival, rapeseed. Feedstuffs, June 23:16. Deaton, J. W„ L. F. Kubena, J. D. May, F. N. Reece, and B. D. Lott, 1973. A noted difference in gizzard weight between cage and floor-reared broilers. Poultry Sci. 52:1217-1218. Hogan-Warburg, A. J., and J. A. Hogan, 1981. Feeding strategies in the development of food recognition in young chicks. Anim. Behav. 29:143-154. Hollister, A. G., and H. S. Nakaue, 1982. The effect of
high fiber diets on growth and carcass composition in selected broiler strains and/or strain crosses. Poultry Sci. 61:1480. (Abstr.) Malone, G. W., and G. W. Chaloupka, 1981. Management and particle size evaluation of processed newspaper litter. Poultry Sci. 60:1691. (Abstr.) Malone, G. W., and G. W. Chaloupka, 1982. Evaluation of shredded newspaper litter materials under various broiler management programs. Poultry Sci. 61:1385. (Abstr.) Malone, G. W„ P. H. Allen, G. W. Chaloupka, and W. F. Ritter, 1982. Recycled paper products as broiler litter. Poultry Sci. 61:2161 — 2165. Malone, G. W., G. W. Chaloupka, and R. J. Eckroade, 1983. Composted municipal garbage for broiler litter. Poultry Sci. 62:414-418. Steel, R.G.D., and J. H. Torrie, 1960. Pages 101-109 in Principles and Procedures of Statistics. McGraw-Hill Book Co., Inc., New York, NY. Van Soest, P. J. 1963. Use of detergents in the analysis of fibrous feeds II. A rapid method for the determination of fiber and lignin. J. Assoc. Offic. Agric. Chem. 46:829. Van Soest, P. J„ and R. H. Wine, 1967. Use of detergents in the analysis of fibrous feeds IV. Determination of plant cell-wall constituents. J. Assoc. Offic. Anal. Chem. 50:50.
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1 The acid (ADF) and neutral detergent fiber (NDF) values for the 21-day period are the average analysis of samples taken 21 days of age. The 22 to 49-day period values are based on analysis at 49 days. Values in parentheses are the fiber contents of the litter treatment. The starter feed ADF and NDF values were 4.24 and 17.19, respectively and 3.73 and 14.86, respectively, for the finisher.
1983 Poultry Science 62:1741-1746 INTRODUCTION
Previous litter research has often demonstrated that litter type has a significant effect on broiler performance. In many cases, these differences have not been explained. In studies with various types of recycled paper products, Malone and Chaloupka (1981, 1982) and Malone et al. (1982, 1983) have found that broilers reared on paper base litters generally had significantly improved body weights and often improved feed efficiency compared to broilers grown on wood shavings or sawdust. In studies with composted municipal garbage (recycled paper base product) as litter, Malone et al. (1983) observed that broilers grown on wood shavings had larger gizzards than broilers reared on paper. Subsequent studies with
1 Published with the approval of the Director of the Delaware Agricultural Experiment Station as Miscellaneous Paper No. 991, Contribution No. 71 of the Department of Animal Science and Agricultural Biochemistry, University of Delaware, Newark, DE 19711. 2 Agricultural Experiment Station. 3 Cooperative Extension Service.
shredded newspaper litter confirmed that gizzard weights were decreased in broilers raised on the paper base litter. Malone and Chaloupka (1982) reported that broilers placed solely on shredded newspaper at an early age had fewer foreign particles in the gizzard and had a lower incidence of coccidial lesions compared to broilers placed on sawdust. From these observations, it would appear that litter consumption may have some role in the response of broilers to type of litter. Caldwell and McDaniel (1982) reported a significant increase in growth and less foreign material in the gizzard of broilers reared on a suspended metal floor than those reared on litter. Gizzard weights were also lower in cage-reared broilers compared to those grown on litter (Deaton et al., 1973). It was the purpose of this investigation to determine the influence of broiler age, litter type, and particle size on litter consumption. MATERIALS AND METHODS
In each of two battery trials, 240 Hubbard x Hubbard male chicks were wing banded and placed in electrically heated starter battery cages. Four pens of 10 chicks each were used
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Downloaded from http://ps.oxfordjournals.org/ at New York University on May 8, 2015
ABSTRACT The influence of broiler age, litter type, and particle size was studied to determine their effects on litter consumption in two battery trials involving 240 broilers each. In Experiment 1, broilers were provided no litter, wood chips, sawdust, wood fibers, processed newspaper, or newspaper fibers ad libitum from 1 to 49 days of age. In Experiment 2, sawdust was provided free choice daily as the only litter source to broilers starting at 1, 7, or 14 days of age until the 21st day. Broilers consumed significantly greater quantities of sawdust and wood fibers than other litter types and sizes. The consumption rate of all materials decreased after 21 days of age. In Experiment 2, consumption of sawdust was highest when provided any time up to 14 days of age. Based on litter intake and the presence of litter in the gizzards, the data revealed significantly greater consumption of sawdust and high concentrations of sawdust in the gizzard; broilers provided wood fibers also had high intakes but low levels in the gizzard; consumption of wood chips was low but the particles were present in the gizzard; and consumption of newspaper based litter was low and little foreign material was found in the gizzard. (Key words: litter, particle size, wood products, newspaper fiber, broiler consumption, growth)
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The influence of broiler age on litter consumption was determined in Experiment 2 using the same facilities as the first study. Sawdust was fed ad libitum for the following time periods: 1 to 21 days of age, 7 to 21 days, 14 to 21 days. A control group was allowed no access to litter. Nonscreened white oak sawdust with approximately 85% of the particles less than .2 cm diameter was obtained from a single
tree directly from a local sawmill. At 7, 14, and 21 days, body weight and feed and litter consumption were determined. Gizzard and liver weights and gizzard litter score were obtained for all broilers at 21 days of age. The gizzard litter score was a subjective score based on a visual observation of gizzard contents. Scores of zero, one, two and three represent no litter, less than 30%, 30 to 60%, and greater than 60% litter in the gizzard contents, respectively. All data were subjected to analysis of variance, and treatments were compared using Duncan's multiple range test when the F-value for treatment from the analysis of variance was below 5% significance (Steel and Torrie, 1960). All percentage data were transformed using arcsin prior to statistical analysis and converted back to the original base following the multiple range test. RESULTS AND DISCUSSION When expressing the litter intake as the percent of total intake of both feed and litter on a weight basis, chicks consumed significantly greater quantities of sawdust and wood fibers between 8 to 21 and 22 to 49 days of age (Table 1). During the first week of age, up to 6.35% of the diet was litter when provided free choice in the form of wood fibers. Consumption of both forms of newspaper and wood chips were low throughout the study, suggesting both type and particle size of litter affects intake. At an early age, the large size of wood chips alone prohibited eating this form of litter. The newspaper based product would appear to be less palatable, perhaps due to its low density and irregular particle size. Both wood fibers and sawdust, however, had texture and density similar to that of the feed. In all treatments, the intake generally decreased after 21 days of age. In the second experiment, chicks provided sawdust at 1 or 7 days of age had litter intakes higher than those having access starting at 14 days, indicating an age-related effect. For those chicks provided sawdust at 1 day, the level of intake remained constant for 2 weeks, then declined. Within each treatment, certain pens had up to four times the litter intake over companion pens, indicating there were apparently other unknown stimuli to encourage litter consumption. Pens with high initial intakes generally continued to have elevated intake levels throughout the study. Hogan-Warburg
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 8, 2015
for each treatment in Experiment 1 and six pens of 10 chicks were used in the second experiment. Of the total 62 cm of feeder space per pen, a solid partition was installed to provide 25% of the trough area for the litter treatments. Water and a commercial type diet were provided ad libitum in both studies. A starter crumble diet containing 24.2% protein and 3186 kcal ME/kg of feed was fed from 1 to 21 days and a finisher pellet diet with 21.0% protein and 3351 kcal/kg was fed from 22 to 49 days. In Experiment 1, the effect of litter particle size and type of litter was evaluated using the following treatments: wood chips (.6 to 1.3 cm wide by 1.3 to 2.5 cm long), sawdust and processed newspaper (.2 to .6 cm diameter), wood fibers and processed newspaper fibers (less than .2 cm diameter), and a control with no material provided. Each litter material was placed in the partitioned area of the trough when the birds were 1 day of age. The wood chips and sawdust were obtained from one Quercus alba (white oak) tree at a local sawmill and the processed newspaper was from the source and process described by Malone et al. (1982). A subsample of wood chips and processed newspaper were ground to obtain the fiber treatments. All treatments were sieved to ensure the desired particle size. From each pen in Experiment 1, 2 birds at 7 and 21 days and the remaining birds at 49 days were necropsied for litter content in the gizzard and for gizzard and liver weights. Gizzards were cleaned, peeled, and trimmed of fat prior to weighing. A fecal sample was collected for a 24-hr period prior to each necropsy date, dried, ground, and analyzed for acid detergent fiber (ADF) (Van Soest, 1963) and neutral detergent fiber (NDF) (Van Soest and Wine, 1967). At 7, 21, and 49 days, all birds were weighed, and feed and litter consumption were determined. At 21 days, all broilers were transferred to a finishing battery unit to allow for increased floor and head space (feeder trough length and design were the same as before).
LITTER CONSUMPTION
As shown in Table 2, body weights generally decreased when litter consumption was above 4% of the diet. With wood fibers in Experiment 1 or the nonscreened sawdust from Experiment 2, there was a consistent effect of high levels of intake on subsequent body weights. In the first experiment, when the male broilers were grown to market age in battery cages, there was high variability in 49-day body weights between individuals and between pens within the same treatment. Part of this variation was associated
with 11% incidence of leg disorders, which affected the weights of all treatments. The variability in weights may account for no treatment effect at 49 days even though the spread in treatment means was wide. In Experiment 2, sawdust provided to broilers after 14 days of age was not detrimental to 21 day weights. Feed efficiency and mortality were not significantly affected by treatment in either study. Based on a subjective score of the amount of litter in the gizzard, birds receiving sawdust had the highest concentration of litter in the gizzard at all ages (Table 3). Those given wood fibers had significant quantities initially (probably associated with high intakes), but the amount of fibers depleted more rapidly than sawdust, possibly as a result of increased passage through the digestive system. Because wood chips would require increased gizzard activity to reduce the particle size, this material may have accumulated in the gizzard, although consumption rates were generally low. Because these battery studies with wood-based products do not simulate floor pen situations, the validity of these results may be questioned. However, in two previous trials in which gizzard scores were recorded by the same person, Malone and Chaloupka (1982) found litter (sawdust) in the gizzards of floor pen birds equal to and, in many cases greater
TABLE 1. Broiler Utter intake as influenced by broiler age, litter size, and type Litter • intake 1
Experiment no.
Litter treatment 2
1-7 days
8 - 2 1 days
1
Wood chips Sawdust Wood fibers Processed newspaper Newspaper fibers No litter
.32C 2.31 b 6.35a .39 b c .15 c 0
,14b 3.08 a 4.82a .49b .29 b 0
Ob .95 a 1.28 a ,10b .04b 0
1—7 days
8 - 1 4 days
1 5 - 2 1 days
4.03 0 0 0
4.52 a 5.23 a 0 0
2.90b 5.18 a 1.9lb 0
2 2 - 4 9 days
V'O)
Sawdust, 1 day Sawdust, 7 days Sawdust, 14 days No sawdust
2
' ' Within each experiment, litter intake means in the same column having different superscripts are significantly different (P<.05). 1 2
Litter intake is expressed as percent of total dietary consumption of both feed and litter on a weight basis.
Litter treatments in Experiment 1 were provided ad libitum starting at day of age. In Experiment 2, sawdust was provided from the day stated until the termination at 21 days of age.
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and Hogan (1981) reported that ingestion of sand varies widely among individuals and the chick's appetite for food gradually develops as a result of an association between stimuli from food and positive long-term aftereffects of food ingestion. Preliminary reports by Malone and Chaloupka (1982) and Caldwell and McDaniel (1982) also suggest that litter eating may be a learned behavioral trait developed at an early age. Based on those chicks having access to sawdust at day of age (Experiment 2), litter consumption peaked within 14 days postexposure, then declined. There appeared to be little desire to eat litter if it was provided for the first time at 14 days of age. However, Bootwalla et al. (1982) recently found that breeder hens reared on wire floors and provided litter in the feeders at 52 weeks of age consumed 18.3 g litter/bird/day.
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TABLE 2. Broiler body weight as influenced by age ofb roller when exposed to various litter types and sizes Experiment no.
Body weight
Litter treatment 1
7 days
Wood chips Sawdust Wood fibers Processed newspaper Newspaper fibers No litter
116.7b 126.5 a 109.5 b 117.4b 119.8 b 121.2*b
Sawdust, 1 day Sawdust, 7 days Sawdust, 14 days No sawdust
117.3a 121.9a 125. l a 120.5a
14 days
21 days
49 days
565.5a 553.7a 512.5b 561.5a 564.2a 552.7a
2264 a 2221 a 2164 a 2236 a 2241 a 2184 a
(g)
517.lb 516.0b 549.8a 546.2a
' ' Within each experiment, body weight means in the same column having different superscripts are significantly different (P<.05). 1 Litter treatments in Experiment 1 were provided ad libitum starting at day of age. In Experiment 2, sawdust was provided from the day stated until the termination at 21 days of age.
than, the levels observed in this study. Consumption and litter content of the gizzard of broilers having access to newspaper were lower than for broilers provided sawdust or wood fibers. Because the fiber in the feed closely resembles wood and newspaper fibers in texture, the gizzard score of the no litter treatment
probably represents dietary fiber rather than litter in Experiment 1. The distinction between litter (sawdust) and feed fiber in the gizzard contents was clear in the second experiment. The size of the gizzard is determined by the muscular activity of the organ to comminute the ingested particles (Branion, 1963); there-
TABLE 3. Broiler gizzard litter score as influer ced by age of broiler exposure to various litter types and sizes Experiment no.
Gizzard litter score1
Litter treatment 2
7 days
21 days
Wood chips Sawdust Wood fibers Processed newspaper Newspaper fibers No litter
.25 b 2.25 a 2.00 a .75 b .75 b .25 b
.13b 2.50 a .38 b .13b .13b .13b
Sawdust, 1 day Sawdust, 7 days Sawdust, 14 days No sawdust
49 days 90b 75 a 62bc 3 3c 17 c 21 c
1.90b 2.28 a 1.62c Od
' ' ' Within each experiment, gizzard litter score means in the same column having different superscripts are significantly different (P<.05). 1 Subjective score of 0 to 3 based on the amount of litter in the gizzard. Values represent: 0, no litter; 1, less than 30%; 2, 30 to 60%; and 3, greater than 60% litter making up the total gizzard content. 2 Litter treatments in Experiment 1 were provided ad libitum starting at day of age. In Experiment 2, sawdust was provided from the day stated until the termination at 21 days of age.
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267.4C 275.5bc 295.0a 286.0ab
LITTER CONSUMPTION
In summary, wood-base products have been a standard and highly desirable litter material for most broiler producing areas. As these conventional sources increase in price and decrease in availability, alternative materials such as newspaper based products are being tested experimentally and commercially with a general improvement in broiler performance in many cases. Based on the results of this and other studies, part of the difference in performance may be associated with litter consumption of the wood based litter products. Chicks with access to wood fibers or nonscreened sawdust during the first 2 weeks of age may consume more than 4% of their diet as litter which apparently has a detrimental effect on subsequent body weight. Crawford et al. (1980) suggest that consumption of shavings may be associated with distance of feed and water from the chicks' heat source. As the distance increased, shavings reared broilers had higher mortality from starve-outs and decreased body weights compared to those placed on chopped straw. Recent new management practices, such as confinement brooding with inadequate feeder space or room temperatures, increased disease stress from high density brooding and the increased appetite of today's broiler stocks may contribute to the problem. Because the sawdust has textural and visual properties
TABLE 4. Broiler gizzard weight as influenced by age of broiler exposure to various litter types and sizes Gizzard weight 1
Experiment no.
Litter treatment2
7 days
21 days
4 9 days
1
Wood chips Sawdust Wood fibers Processed newspaper Newspaper fibers No litter
4.64C 5.19a 5.43a 5.08ab 4.70bc 4.60C
2.35abc a
1.36 a 1.40 a 1.35 a 1.24b 1.24b 1.3 l a b
2
Sawdust, 1 day Sawdust, 7 days Sawdust, 14 days No sawdust
2.58 2.46ab 2.16c 2.20DC 2.32abc 2.92a 3.02a 2.58b 2.29c
' ' Within each experiment, gizzard weight means in the same column having different superscripts are significantly different (P<.05). 1
Gizzard weight is expressed as percent of live body weight. Litter treatments in Experiment 1 were provided ad libitum starting at day of age. In Experiment 2, sawdust was provided from the day stated until the termination at 21 days of age. 2
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fore, one would expect greater gizzard weights in treatments with high litter intakes. Treatment differences in gizzard weights (Table 4) followed a pattern very similar to that shown by gizzard litter scores. High consumption of wood fibers and sawdust at an early age increased gizzard weight over the control, newspaper fibers, and wood chips at 7 days, whereas both particle size and total intake appeared to influence organ size at subsequent ages. For broilers given litter in the form of sawdust, the size of the gizzard may be a sensitive indicator of litter consumption. None of the treatments had a significant effect on liver weight. When the fecal fiber data from 1 to 21 days of age were pooled, broilers fed wood fibers had significantly higher excretion of ADF than all other treatments (Table 5). The excretion of NDF for the first 21 days was also significantly higher with both sawdust and wood fiber than other litter types. Fecal ADF and NDF values at 49 days and hemicellulose values at all ages were similar between treatments. These fiber values tend to parallel litter intake in that both wood fiber and sawdust had the highest intake and excretion of the fiber. Part of the variability within treatments in this study may have been associated with individual differences in fiber digestibility within strain as suggested by Hollister and Nakaue (1982).
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MALONE ET AL. TABLE 5. Fiber content of broiler feces as influenced by litter size and type 1-21 days'
Experiment no.
Litter treatment 2
ADF
1
Wood chips Sawdust Wood fibers Processed newspaper Newspaper fibers No litter
19.40b 21.90b 25.74* 20.76° 19.73° 21.17b
(73.7) (74.0) (77.2) (78.3)
22- -49 days 1
NDF
ADF
NDF
34.92 b 41.43* (87.9) 41.45 a (89.9) 37.10b (94.0) 36.56b (94.0) 36.54 b
21.02* 18.44* 18.52* 21.43* 15.73* 17.10*
35.01* 33.14a 35.64* 33.82* 34.05* 35.36*
ab ' Within each column, fiber values having different superscripts are significantly different (P-C05).
2
Litter treatments in Experiment 1 were provided ad libitum starting at day of age.
similar to feed, management factors that minimize litter consumption at an early age should prove beneficial. REFERENCES Bootwalla, S. M„ R. H. Harms, and H. R. Wilson, 1982. The influence of litter vs. wire floor on the weight and specific gravity of eggs from broiler breeder hens. Poultry Sci. 61:1421-1422. (Abstr). Branion, H. D., 1963. An abnormality of the proventriculus and gizzard of chicks. Poultry Sci. 42:736-743. Caldwell, D. K., and G. R. McDaniel, 1982. Performance of broilers reared on a plastic-coated metal floor and in a conventional environment. Poultry Sci. 61:1371. (Abstr.) Crawford, R. D., J. B. O'Neil, and T. A. Scott, 1980. Canadian research includes chick survival, rapeseed. Feedstuffs, June 23:16. Deaton, J. W„ L. F. Kubena, J. D. May, F. N. Reece, and B. D. Lott, 1973. A noted difference in gizzard weight between cage and floor-reared broilers. Poultry Sci. 52:1217-1218. Hogan-Warburg, A. J., and J. A. Hogan, 1981. Feeding strategies in the development of food recognition in young chicks. Anim. Behav. 29:143-154. Hollister, A. G., and H. S. Nakaue, 1982. The effect of
high fiber diets on growth and carcass composition in selected broiler strains and/or strain crosses. Poultry Sci. 61:1480. (Abstr.) Malone, G. W., and G. W. Chaloupka, 1981. Management and particle size evaluation of processed newspaper litter. Poultry Sci. 60:1691. (Abstr.) Malone, G. W., and G. W. Chaloupka, 1982. Evaluation of shredded newspaper litter materials under various broiler management programs. Poultry Sci. 61:1385. (Abstr.) Malone, G. W„ P. H. Allen, G. W. Chaloupka, and W. F. Ritter, 1982. Recycled paper products as broiler litter. Poultry Sci. 61:2161 — 2165. Malone, G. W., G. W. Chaloupka, and R. J. Eckroade, 1983. Composted municipal garbage for broiler litter. Poultry Sci. 62:414-418. Steel, R.G.D., and J. H. Torrie, 1960. Pages 101-109 in Principles and Procedures of Statistics. McGraw-Hill Book Co., Inc., New York, NY. Van Soest, P. J. 1963. Use of detergents in the analysis of fibrous feeds II. A rapid method for the determination of fiber and lignin. J. Assoc. Offic. Agric. Chem. 46:829. Van Soest, P. J„ and R. H. Wine, 1967. Use of detergents in the analysis of fibrous feeds IV. Determination of plant cell-wall constituents. J. Assoc. Offic. Anal. Chem. 50:50.
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1 The acid (ADF) and neutral detergent fiber (NDF) values for the 21-day period are the average analysis of samples taken 21 days of age. The 22 to 49-day period values are based on analysis at 49 days. Values in parentheses are the fiber contents of the litter treatment. The starter feed ADF and NDF values were 4.24 and 17.19, respectively and 3.73 and 14.86, respectively, for the finisher.