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Studies on Energy Utilization by the Growing Chick1
930
F. L. CHERMS, JR.
Lerner, I. M., 1950. Population Genetics and Animal Improvement. The Cambridge University Press, Cambridge, England.
McCartney, M. G., 1956. Heritability of egg weight in White Holland Turkeys. Poultry Sci. 35: 230-231.
Studies on Energy Utilization by the Growing Chick 1 E. H. BOSSARD AND G. F. COMBS Poultry Department, University of Maryland, College Park, Maryland (Received for publication September 1, 1960)
RODUCTIVE energy values (Fraps, 1946) have been widely used as a measure of the biological value of ingredients. Recently, Hill and Anderson (1958) and Potter (1958) have shown that the metabolizable energy value of a diet is more precisely measured than is the productive energy content. Most metabolizable energy values have been determined by replacing a standard ingredient or a portion of a standard ration with the test ingredient. Another method is to vary widely the amounts of all energyproducing ingredients and to solve for their separate metabolizable energy contents by the method of least squares, as described by Metta and Mitchell (1954) and Bernstein et al. (1956). Productive or net energy attempts to correct for heat increment, or that portion of the metabolizable energy expended for its utilization by the animal. The inclusion of fat in isocaloric rations has been reported by Forbes et al. (1946) to result in a decreased heat increment in the rat, thus making available a greater proportion of the metabolizable energy for productive purposes. Forbes and Swift (1944) observed that the heat increment of a diet could not be computed from the specific dynamic ef1
Scientific Article No. A875 Contribution No. 3185 of the Maryland Agricultural Experiment Station (Department of Poultry Husbandry).
feet of each of its component parts, but varied with differences in nutrient combination. The work reported in this paper involves a study of energy utilization in the chick, using the multiple regression analysis approach in determining the energy content of ingredients in diets differing widely in carbohydrate, protein and fat levels. EXPERIMENTAL Laboratory. Two experiments were conducted, both involving four diets each of which were fed to duplicate groups of chicks maintained in electrically heated battery brooders with raised wire floors from 2 to 4 weeks of age. Feed and water were provided ad libitum. In experiment 1, Van tress X Arbor Acre crossbreed males were used, while New Hampshire X Columbian Rock crossbred chicks of both sexes were used in experiment 2. Prior to the initiation of both experiments, a larger number of day-old chicks were reared under similar conditions and fed a practical chick starter. At the end of the 13th day of this preliminary period, the chicks were fasted for 20 hours, weighed and distributed into uniform groups on the basis of body weight, discarding approximately one third of the chicks from the extreme weight ranges. Thus, in each experiment, nine groups of 14 chicks each were selected, one of which was sacrified without loss of blood for gross
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ENERGY UTILIZATION
TABLE 1.—Coin position of experimental chick diets Ingredients
Diet 1 Diet 2 Diet 3 Diet 4 Percent
1
Cerelose Isolated soybean Protein 2 Corn oil Glycine DL-methionine Chromic oxide DPPD 3 Proc. penicillin (50% mix) Minerals4 Vitamins5
Analysis: Metabolizable Cal./lb. Protein (NX6.25)
32.8
28.6
49.9
61.
39.8 20. 0.8 0.8 0.35 0.0125
49.6 14. 1. 1. 0.35 0.0125
34.9 8. 0.7 0.7 0.35 0.0125
30. 2. 0.6 0.6 0.35 0.0125
0.001 5.058 0.384
0.001 5.058 0.384
0.001 5.058 0.384
0.001 5.058 0.384
100.
100.
100.
100.
1867 34.0
1750 42.3
1586 29.8
1432 25.7
1 Glucose monohydrate (Cerelose); 9.4 and 9.2% moisture in experiments 1 and 2, respectively. 2 Drackett C-l assay protein; 8.9 and 8.8% moisture in experiments 1 and 2, respectively. 3 Diphenylparaphenylenediamine. 4 Minerals added, % of diet: Ca C0 3 , 0.75; Ca3 (P0 4 ) 2 , 2.3; K 2 HP0 4 , 0.8; Mg SCv 7H 2 O,0.5; NaCl, 0.6; FeS0 4 -7H 2 0, 0.05; CuS0 4 -5H 2 0, 0.002; Mn S0 4 -H 2 0, 0.031; CoSOv7H 2 0, 0.0002; Na Br, 0.002; Zn CI, 0.002; KI, 0.004; H 3 B0 3 , 0.001; A1K(S0 4 ) 2 -12H 2 0, 0.01 Na Mo0 4 -2 H 2 0, 0.001; and Na 2 S i 0 3 - 9 H 2 0 , 0.005. 5 Vitamins added, amount per 100 gms. of diet: 50 mg. vitamin A cone. (20,000 I.U./gm.), 10 gm. vitamin D 3 cone. (15,000 I.C U. gm.) 200 mg. choline chloride (100%), 3 mg. alpha-tocopheryl acetate, 3 mg. vitamin Bi 2 , 0.5 mg. menadione, 100.0 mg. inositol, 0.5 mg. paraaminobenzoic acid 0.04 mg. biotin, 0.8 mg. folacin, 1 mg. pyridoxine HC1, 5 mg. niacin, 4 mg. calcium pantothenate, 2 mg. riboflavin, 2 mg. thiamine HC1 and 2 mg. ascorbic acid.
experimental period, droppings were collected in aluminum foil. These samples were removed at least twice daily and dried in a forced air oven, ground and a uniform sample placed in a stoppered flask and stored at 5°C. until chromic oxide, nitrogen and gross energy determinations could be made. At the end of each experimental period, the chicks were again fasted for 20 hours and weighed. Then seven birds in experiment 1 and six birds in experiment 2, selected to be representative on the basis of body weight, were sacrified from each pen for gross energy and nitrogen determination. Later the carcasses were partially thawed, reweighed, and ground in a large meat grinder using a plate with % inch holes. All the sacrificed birds from each pen, including the feathers and digestive tract, were ground together and mixed thoroughly. Approximately 1 kilogram of this mixture was then placed in a one-gallon capacity Waring blendor, along with an equal weight of cold water, and blended for about 3 minutes. Then samples were removed for lyophilizing and three weighed porcelain crucibles were filled with samples for nitrogen determinations. Each porcelain crucible was placed inside the Kjeldahl flask and remained there throughout the determination. Carcass samples were lyophilized to constant weight and stored in a desiccator at 5°C. until samples were weighed for gross energy determination. Moisture determinations were made by the A.O.A.C. method on samples of cerelose and isolated soybean protein used in the diets. Two or more samples of each diet and of the feces from each of the sixteen pens were used in the determination of gross energy content, using the plain Parr bomb calorimeter, and for nitrogen determinations by the Kjeldahl method. Analysis of feces for chromic oxide was performed by the
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energy and nitrogen analysis. These were weighed and kept frozen until the analyses were performed. The four experimental rations, as given in Table 1, were formulated to contain widely different levels of corn oil, glucose monohydrate (Cerelose), and a proteinamino acid mixture composed of 96.1% isolated soybean protein (Drackett C-l Assay Protein) and 1.95% each of glycine and DL-methionine. These diets are considered to be adequate in all known required nutrients. During the last three days of the
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E. H. BOSSARD AND G. F. COMBS
the following equation: b4, a4 + C = b ^ i + b2a2 + b3a3. Where b4 = Calories of net energy required daily for maintenance of 1 kilogram of body weight; a4 = No. of days of period X y2 (initial weight in kg. + final weight in kg.); C = Calories of gross energy gained in the carcass, corrected for nitrogen retention, during the period (dependent variate); bi, b2 and b3 = Calories of net energy per gram of glucose, corn oil and protein-amino acid mixture, respectively; and a ^ and a3 = grams of glucose, corn oil, and protein-amino acid mixture, respectively, eaten during the period. Calculations showed that the maintenance term could not be determined accurately by this equation due to its small range of variation. Hence, maintenance was approximated for each experiment by assuming that on the average for all diets combined, 70% of the metabolizable energy was useful as productive energy as defined by Fraps (1946). Productive energy is a net energy term uncorrected for nitrog2n retention. This arbitrary values of 70% was derived from a comparison of productive and metabolizable energy of Titus (1955). Net energy Calories used for maintenance were calculated by substracting the Calories gained in the carcass, uncorrected for nitrogen retention, from the calculated Calories of productive energy consumed for each experiment. Then the average number of kilograms of bird maintained per day was divided into the total net energy used daily for maintenance to approximate the Calories needed for maintenance per kilogram of bird per day. Calories used for maintenance plus Calories deposited in the carcass (corrected for nitrogen retention as above) by pens, gave the net energy value of each ration. This, likewise, was distributed among its energy producing ingredients by use of multiple-regression analysis to find ingredient net energy values.
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method of Bolin and Dinusson (1957). The value of 8.22 Calories per gram of nitrogen retained in the carcass was used as a correction in calcluating metabolizable energy content of each ration as suggested by Hill and Anderson (1958). Statistical. Multiple-regression analysis was used with the data from each experiment separately and with the combined data from both to determine the metabolizable energy content of each ingredient. Data obtained from each pen were fitted to an equation with the determined metabolizable energy intake and the grams of each of the three energy-supplying ingredients consumed representing that ammount associated with one gram of marker (chromic oxide) eaten. The assumptions made in the multipleregression analysis approach are that the determined nitrogen corrected metabolizable energy intake (y) for any of the diets is expressible as a linear function of the fixed variables, ai (gms. glucose eaten), a2 (gms. corn oil eaten), and a3 (gms. proteinamino acid mixture eaten); and that the residual errors are normally and independently distributed around zero with constant variance. In order that the calculated caloric value of these ingredients could be used in other "balanced" diets containing other ingredients, the equations were passed through the origin instead of inserting a floating constant b0. The multiple-regression equation used was as follows: y = Kai + b2a2 + b3a3. The values of b 1; b 2 , and b 3 were computed by the abbreviated Doolittle method for inverting a matrix (Anderson and Bancroft, 1952). The b 1 ; b 2 , and b 3 represent estimates of the metabolizable Calories per gram of glucose, corn oil, and the proteinamino acid mixture, respectively. Multiple-regression analysis to determine net energy (corrected to nitrogen equilibrium) of ingredients was attempted with
933
ENERGY UTILIZATION
Nitrogen corrected metabolizable Calories consumed, less the net energy (nitrogen corrected) intake, yielded a calculated amount of metabolizable energy used for heat increment with the different rations. Net energy values uncorrected for nitrogen retention, also were calculated for ingredients by use of multiple-regression analysis. These would be more nearly comparable to productive energy values.
TABLE 3.—Metabolizable and net energy values obtained for cerelose, corn oil and isolated soybean protein-amino acid mixture, with standard deviations1
Experiment
Cerelose
Corn oil
Drackett C-l protein plus amino acids2
Met. Cal./gm. (moisture -free basis) 1 2 1 &2
3.54 + .08 3.31 + .08 3.43 + .09
8.63 + .28 7.74 + .28 8.18 + .31
3.70+.15 4.02+.16 3.86+.18
Net. Cal.,/gin. (uncorrected for N. retention) RESULTS AND DISCUSSION
TABLE 2.—Energy values obtained for experimental diets, with standard deviation, (dry basis)1 Gross Metabolizabli^ N e t Calories Net Diet Exp. Calories/ Calories 2 / " (uncorrected Calories 2 / for N gm. gm. retention/gm.) ^m' 1
1 2
2
3
4
1
5.005 4.995
4.171 4.063
av.
5.000
4 . 1 1 7 + .066 2 . 7 8 1 + .029 2 . 5 7 1 + .023
1 2
4.823 4.830
3.868 3.946
av.
4.827
3 . 8 5 7 + .010 2 . 7 0 3 + .061 2 . 4 9 + .063
1 2
4.239 4.229
3.555 3.440
av.
4.234
3 . 4 9 8 + .072 2 . 4 7 0 + .094 2 . 2 7 1 + .076
1 2
3.750 3.774
3.163 3.148
av.
3.762
3 . 1 5 6 + .020 2 . 2 7 1 + . 0 2 4 2 . 1 0 6 + .019
2.784 2.779
2.703 2.702
2.540 2.400
2.287 2.255
2.561 2.582
2.478 2.504
2.325 2.217
2.112 2.100
Each value based on data from duplicate groups of 14 chicks each. 2 Corrected to nitrogen equilibrium.
1 &2
2.36 + .11
4.58± .39
3.07+.22
Net Cal./gm. (corrected to N. equilibrium) 1 &2
2.21 + .09
4.28 + .33
2.79+.18
1
95% confidence limits are obtained by multiplying the standard deviation by 2.776 for experiments 1 and 2 separately, and 2.179 for experiments 1 and 2 cominbed. 2 Composed of 96.1% isolated soybean protein (Drackett C-l) and 1.95% each of glycine and DLmethionine.
indicates that the multiple-regression analysis is not sufficiently accurate when three or more variables are solved simultaneously with biological data. It is not possible to eliminate entirely correlations between the variable in such experiments; hence the normal variations encountered in such data renders this approach unsatisfactory where a high degree of accuracy is desired. The calculated net energy values obtained for each diet with and without corrections to nitrogen equilibrium, also are given in Table 2. These were very reproducible with little more variation than was observed for the metabolizable energy determinations. Table 3 presents the corresponding net energy values for the diet ingredients. The same variation in values was found between experiments as was noted for metabolizable energy. The metabolizable energy values obtained for cerelose and corn oil in this study are 1556 and 3710 Calories per pound on a dry basis, respectively, using the data from both experiments. These values compare with
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The gross and metabolizable energy values obtained for the four experimental diets are given in Table 2. The metabolizable energy content of the ingredients, as obtained by multiple-regression analysis using the data from experiments 1 and 2 separately, and both combined are given in Table 3. Values of 3.54, 8.63 and 3.70 Calories per gram were obtained in experiment 1 and 3.31, 7.74 and 4.02 in experiment 2 for cerelose, corn oil and the protein-amino acid mixture, respectively. These widely different metabolizable energy values for each ingredient between experiments, with excellent agreement in the metabolizable energy values obtained for each diet
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E. H. BOSSARD AND G. F. COMBS
Although satisfactory estimates of ingredient Caloric values may be obtained sometimes by use of multiple-regression analysis using diets containing variable amounts of three ingredients (Metta and Mitchell, 1954), the present study and that by Bernstein et al. (1956) would indicate that poor separation of the Caloric contribution of each ingredient in the diet is common. The data concerning weight gain, body composition, feed conversion and energy consumption by diets is given in Table 4. The mean gains in body weight were significantly greater (P < .01) for the chicks fed the diets containing 8 or more percent corn oil than for those receiving ration 4. The chicks which received diet 4 had a significantly higher gross energy content of
TABLE 4.—Body weight gain, body composition, feet i conversion and energy requirements as influenced by diets differing in energy source^ Diet
Exp.
Av.2 gain/gm.
Body composition3 Cal. gross % energy/gm. Moist.
1
2
3
4
1
Consumption per gram gain
Protein
%
Feed, gms.
Gross Cal.
Met. Cal.4
Net Cal. (uncor. for N. ret.) 5
Net Cal.4
1 2
300 286
1.77 1.71
68.8 69.8
20.0 19.2
1.26 1.31
6.20 6.52
5.25 5.30
3.51 3.62
3.22 3.37
av.
293
1.74
69.3
19.6
1.28
6.41
5.28
3.57
3.30
1 2
297 279
1.69 1.73
69.6 69.6
20.3 20.1
1.26 1.36
6.06 6.60
4.86 5.26
3.39 3.69
3.11 3.43
av.
288
1.71
69.6
20.2
1.31
6.33
5.06
3.54
3.27
1 2
292 281
1.77 1.73
68.4 69.2
21.1 20.5
1.38 1.53
5.85 6.50
4.91 5.28
3.51 3.71
3.21 3.43
av.
286
1.75
68.8
20.8
1.46
6.17
5.10
3.61
3.32
1 2
272 258
1.85 1.83
68.1 68.5
20.4 19.9
1.63 1.74
6.10 6.58
5.14 5.49
3.71 3.93
3.43 3.66
av.
265
1.84
68.3
20.2
1.68
6.34
5.32
3.82
3.55
Values represent averages for replicated groups of 14 chicks each. 14-28 day gain in exp. 1, 14-29 day gains in exp. 2. Initial body weights at 14 days averaged 159 and 145 grams in experiments 1 and 2, respectively. 3 Values apply to 28th and 29th day of age in experiments 1, and 2 respectively. Calories of gross energy per gram of carcass averaged 1.72 and 1.60 at 14 days in experiments 1 and 2, respectively. 4 Corrected to nitrogen balance. 6 Similar to productive energy values. 2
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1633 (Potter and Matterson, 1960) Calories per pound and 1652 (Anderson et al., 1958) for cerelose, dry basis, and with 4000 (Potter and Matterson, 1960), 4000 and 4070 (Hill and Renner, 1957), and 3838 to 3960 (Donaldson, 1957) Calories per pound for corn oil. The uncorrected net energy (productive energy) values obtained for cerelose and corn oil were 1071 and 2078 Calories per pound (dry basis), respectively. These values compare with 1271 (Anderson, 1955) and 1125 and 1506 (Anderson et al, 1958) Calories per pound for cerelose, and 2100 Calories per pound for corn oil (Fraps, 1946). Estimates of the value of fats by Hill (1956) and Titus (1955), suggest a higher productive energy value for corn oil.
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ENERGY UTILIZATION
TABLE 5.—Nitrogen intake, retention and excretion of chicks fed diets varying in protein level and energy source1
Diet
1 2 3 4
Gms. nitrogen consumed/ % nitrogen retained in chick carcass period 20.44 25.47 19.91 18.32
46.8 38.3 51.0 49.4
% nitrogen 2 excreted 45.0 54.1 45.7 44.3
1 Each value based on data for 4 groups of 14 chicks each (both experiments). 2 Based on data collected during last 3 days of each experiment.
spectively. The differences are not significant. The percent of the metabolizable energy intake in the carcass (Table 6) was significantly greater (P < .01) for diet 4 than for diets 1 and 2. This difference appears to be inversely related to fat level with no apparent effect due to protein level. Similarly, the percent of metabolizable energy used for heat increment, as calculated, was lowest for chicks fed the low-fat diet 4 and highest for the chicks fed the 20% fat diet 1 (P < .01). A similar significant difference (P < .01) was obtained between diets 1 and 4 for percent of metabolizable Calories used as net energy (nitrogen corrected). The maintenance requirements could not be determined in these trials, but were calculated by assuming that an average of 70% of the metabolizable energy for all diets in each experiment was productive or net energy uncorrected for nitrogen retention as described above. This assumed relationship yielded maintenance requirements of 118 and 124 Calories of net energy per kilogram of body weight per day for chicks in experiments 1 and 2, respectively. In similar studies with chicks fed purified diets, Potter (1958) obtained a maintenance requirement of 121 Calories per kilogram of body weight per day, which is es-
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the carcass (P < .01) than those fed the other rations. The intake of net, but not metabolizable energy, per gram gain was correspondingly greater (P < .01) for the chicks fed diet 4 than for diet 1. The average total nitrogen intake per chick, percent of nitrogen ingested which was retained in the body during the experimental period and percent of ingested nitrogen which was excreted during the last 3 days are given in Table 5. The metabolizable Calories per pound for each percent protein were 54, 41, 53, and 54 in diets 1, 2, 3, and 4, respectively. As expected, a smaller percent of the nitrogen consumed was retained in the carcass and more was excreted by chicks fed the high-protein diet 2 than for the chicks fed the other diets (P < .01). The total nitrogen recovered ranged from 91.8 to 96.7%. The fact that nitrogen retention was based on difference in carcass content from start to finish of each experiment, while the nitrogen excretion was measured only during the last 3 days, may explain in part the incomplete recovery. These differences in nitrogen retention, as a result of differences in protein intake, show the need for adjusting net energy values as well as metabolizable energy values, for nitrogen retention if reproducible values are to be expected. The percent of gross energy metabolized and proportion of metabolizable energy used for growth, maintenance and heat increment, as influenced by energy source, are given in Table 6. The expected reduction in the percent of gross energy which was metabolizable (corrected for nitrogen retention)" for the high protein diet 2 is eliminated if the gross energy values are also corrected for nitrogen content (less 8.22 Calories per gram of nitrogen). Thus, an average of 90.4, 90.3, 91.0 and 92.2% of the nitrogen corrected gross energy was metabolized for diets 1, 2, 3, and 4, re-
936
E. H. BOSSARD AND G. F. COMBS TABLE 6.—Percent of gross energy metabolized and proportion of metabolizable energy used for growth, maintenance and heat increment by the growing chick1
Diet
Exp.
% of gross energy metabolized2
Energy retained in carcass2
Energy Energy used used for for heat 3 maintenance increment3
Net energy (uncorrected for N retained)'1
Net energy2
(As % of metabolizable energy consumed) 1
2
4
83.4 81.4
28.9 28.3
32.5 35.3
38.6 36.5
66.8 68.5
61.4 63.6
av.
82.3
28.6
33.9
37.5
67.6
62.5
1 2
80.2 79.5
28.7 29.1
35.4 36.0
35.9 34.9
69.9 70.2
64.1 65.1
av.
79.9
28.9
35.7
35.4
70.1
64.6
1 2
83.9 81.4
30.1 28.7
35.3 35.7
34.6 35.5
71.4 69.8
65.4 64.5
av.
82.6
29.4
35.5
35.1
70.6
64.9
1 2
84.4 83.5
31.8 30.8
34.9 35.9
33.3 33.3
72.3 71.7
66.7 66.7
av.
83.9
31.3
35.4
33.3
72.0
66.7
1
Each value represents average of two replicates of 14 chicks each. Corrected to nitrogen equilibrium. Based on maintenance values derived by assuming that 70% of the metabolizable energy for all diets combined in each experiment was available as productive energy (see text). 4 Similar to productive energy values. 2
3
sentially the same as that calculated herein. Furthermore, any error in the maintenance requirement values used would influence the calculated heat increment values by almost a constant amount, and would effect, little, their relative relationships. Since the growth rate was very similar, little error also is expected in relating the maintenance requirement as a direct function of body weight. The significantly lower percentage of the metabolizable energy retained in the carcass and significantly higher amount used for heat increment by the chicks fed the 20% fat diet 1 than by those fed the 2% fat diet, is noteworthy. This apparent increase in proportion of metabolizable energy used for heat increment as the level of corn oil was increased, is not in agreement with the results of Swift et al. (1959). These workers found no appreciable difference in heat production by humans fed equal amounts of protein and energy daily
but containing widely different amounts of fat. The heat loss should vary with the specific metabolic reactions and hence, the heat increment in the metabolism of fat Calories might differ if the fat is oxidized or stored as body fat. The proportion of Calories from fat to other Calories in the diet, and tendency of the animal to store fat, might influence the effect of dietary fat on heat increment. The higher gross energy content of the carcass of diet 4 fed chicks, than for chicks fed the other diets, would suggest that the body fat content was also greater. These observations suggest that dietary fat actually may increase the heat increment of a diet provided it is largely oxidized rather than stored by the chick. SUMMARY Studies on energy utilization were conducted with two to four week old chicks fed ad libitum amounts of four rations contain-
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3
1 2
ENERGY UTILIZATION
ACKNOWLEDGMENTS
The authors are indebted to Merck & Co., Inc., Rahway, N.J., for supplying procaine penicillin and crystalline vitamins; Nopco Chemical Co., Harrison, N.J., for vitamin A & D 3 supplements; Limecrest Research Laboratory, Newton, N.J., for trace minerals; E. F. Drew & Co., Inc., New York, N.Y., for corn oil; Monsanto Chemical Co., St. Louis, Mo., for glycine; E. I. duPont de Nemours & Co., Inc., Wilmington, Del., for DL-methionine; Lederle Laboratories, Pearl River, N.Y., for folacin; and Hoffman LaRoche, Inc., Nutley, N.J., for biotin used in this study. REFERENCES Anderson, D. L., 1955. Comparative studies on the determination of metabolizable and productive energy with the growing chick. Ph.D. Thesis, Cornell University. Anderson, D. L., F. W. Hill and R. Renner, 1958. Studies of the metabolizable and productive
energy of glucose for the growing chick. J. Nutrition, 65: 561-574. Anderson, R. L., and T. A. Bancroft, 1952. Statistical Theory in Research. McGraw-Hill Book Co., Inc., New York, N.Y., p. 339. Association of Official Agricultural Chemists, 1945. Methods of Analysis, 6th edition. Bernstein, L. M., M. I. Grossman, J. M. Iacono, H. J. Kizywicki, L. M. Levey and E. A. Francis, 1956. Determination of the metabolizable energy of purified foodstuffs for human subjects. U.S. Med. Nutr. Lab. Rpt. No. 193, Denver. Bolin, D. W., and W. E. Dinusson, 1957. The determination of chromic oxide in feeds and feces with perchloric acid and molybdenum used as a catalyst. Exp. Sta., Fargo, N.D. (Mimeo). Donaldson, W. E., 1957. Studies on the mechanisms of fat utilization and appetite in chickens and turkeys. Ph.D. Thesis, U. of Maryland. Forbes, E. B., and R. W. Swift, 1944. Associative dynamic effects of protein, carbohydrate and fat. J. Nutrition, 27: 453-468. (Also see Nutr. Rev. 3 : 83, 1945). Forbes, E. B., R. W. Swift, W. H. James, J. W. Bratzler and A. Black, 1946. Further experiments on the relation of fat to economy of food utilization. J. Nutrition, 32: 387-396. Fraps, G. S., 1946. Composition and productive energy of poultry feeds and rations. Texas Agr. Exp. Sta. Bull. No. 678. Hill, F. W., 1956. Studies of the energy requirements of chickens. 4. Evidence for a linear relationship between dietary productive energy level and the efficiency of egg production. Poultry Sci. 35: 59-63. Hill, F. W., and D. L. Anderson, 1958. Comparison of metabolizable energy and productive energy determinations with growing chicks. J. Nutrition, 64: 587-603. Hill, F. W., and R. Renner, 1957. Metabolizable energy values of feedstuffs for poultry and their use in formulation of rations. Pro. 1957 Cornell Nutrition Conf. for Feed Mfg., pp. 22-32. Metta, V. C , and H. H. Mitchell, 1954. Determination of the metabolizable energy of organic nutients for rats. J. Nutrition, 52 : 601-610. Potter, L. M., 1958. Evaluation of alpha cellulose for its metabolizable and productive energy and a comparison of methods of determining metabolizable energy in the chick. Ph.D. Thesis, Connecticut (Storrs). Potter, L. M., and L. D. Matterson, 1960. The metabolizable energy for feed ingredients for chickens. Connecticut (Storrs) Agr. Exp. Sta. Prog. Rpt. No. 39. Titus, H. W., 1955. The Scientific Feeding of Chick-
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ing widely varying levels of glucose (cerelose), corn oil and soybean protein plus amino acids. Chicks which received a lowfat diet (2 % corn oil), showed slightly lower gains in weight, higher gross energy content per gram of carcass gain, greater retention of metabolizable energy in the carcass and less heat increment as a percentage of metabolizable energy intake than chicks fed a ration containing 20% corn oil. No measurable differences in heat increment or carcass composition were attributed specifically to the carbohydrate or protein level of the rations. Multiple-regression analysis was used to determine estimates of metabolizable and net energy values of the three ingredients. Limited success was obtained by this method due to biological variation, linear correlation among levels of ingredients in rations and possible variation in metabolizable energy value of each ingredient according to amounts of the other ingredients present in the ration.
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E. H. BOSSARD AND G. F. COMBS
ens. The Interstate Printers and Publishers, Inc., Danville, 111., p. 297. Swift, R. W., G. P. Barron, K. H. Fisher, R. L. Cowan, E. W. Hartsook, T. V. Hershberger, E.
Keck, R. P. King, T. A. Long and M. E. Berry, 1959. The utilization of dietary protein and energy as affected by fat and carbohydrate. J. Nutrition, 68: 281-289.
Some Effects of Saline Waters on Chicks, Laying Hens, Poults, and Ducklings 1 Departments
L. M. KRISTA,2 C. W. CARLSON AND 0. E. OLSON of Poultry Husbandry and Station Biochemistry, South Dakota Experiment Station, Brookings, South Dakota
Agricultural
(Received for publication September 6, 1960)
L
ARGE quantities of sodium chloride, ' sodium sulfate, and magnesium sulfate render so-called saline waters unsuitable for livestock and poultry consumption. Although sodium chloride is an essential ingredient in the poultry diet, relatively small amounts are required. Selye (1943) reported excessive intakes of sodium chloride via feed or water to cause sudden mortality. He and Peterson (1943) reported 2% sodium chloride in solution to be highly toxic, whereas 2% in feed resulted only in wet litter production. As little as 0.5% salt in solution was reported toxic by Selye (1943). These findings were supported by Field and Eveans (1946) as well as by Kare and Biely (1948). The latter workers found that chicks could tolerate approximately 4% sodium chloride in feed before showing toxic effects, whereas Barlow et al. (1948) reported 3 % to be toxic. Equal toxicities were reported by Kare and Biely (1948) for 0.3% and 0.9% salt in solution as compared respectively to 0.8% and 4.13% salt in the feed. 'Approved for publication by the Director of the South Dakota Agricultural Experiment Station as Journal Series No. 492. From the senior author's M.S. degree thesis. 2 Present address: University of Minnesota, St. Paul.
According to Blaxland (1946), Selye (1943), Quigley and Waite (1932), and Kare and Biely (1948) older chickens are more resistant to salt toxicity than baby chicks, with various individuals within classes showing marked differences in tolerance to salt. Scrivner (1946) found that 1% sodium chloride in the feed for turkey poults was without effect, whereas 1% in water resulted in 100% mortality, with edema and ascites. Sodium chloride at 2 % in the water produced stupor within 48 hours; however, edema and ascites were not evident at the time of death. At 2% in the feed, half of the poults showed edema and ascites. Matterson et al. (1946) reported that poults could tolerate up to 2% sodium chloride in a semi-purified salt-free diet similar to the results reported by Batchelder (1946). James (1946) reported no adverse effects of 1% sodium chloride in the feed, whereas 2% increased water consumption and decreased feed consumption and rate of gain. The results of studies on the effects of graded levels of salt solutions for chicks, laying hens, turkey poults, and ducklings will be presented herewith. CHICKS
Procedure. Two experiments were conducted using day-old Single Comb White Leghorn chicks which were wing banded,
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INTRODUCTION
F. L. CHERMS, JR.
Lerner, I. M., 1950. Population Genetics and Animal Improvement. The Cambridge University Press, Cambridge, England.
McCartney, M. G., 1956. Heritability of egg weight in White Holland Turkeys. Poultry Sci. 35: 230-231.
Studies on Energy Utilization by the Growing Chick 1 E. H. BOSSARD AND G. F. COMBS Poultry Department, University of Maryland, College Park, Maryland (Received for publication September 1, 1960)
RODUCTIVE energy values (Fraps, 1946) have been widely used as a measure of the biological value of ingredients. Recently, Hill and Anderson (1958) and Potter (1958) have shown that the metabolizable energy value of a diet is more precisely measured than is the productive energy content. Most metabolizable energy values have been determined by replacing a standard ingredient or a portion of a standard ration with the test ingredient. Another method is to vary widely the amounts of all energyproducing ingredients and to solve for their separate metabolizable energy contents by the method of least squares, as described by Metta and Mitchell (1954) and Bernstein et al. (1956). Productive or net energy attempts to correct for heat increment, or that portion of the metabolizable energy expended for its utilization by the animal. The inclusion of fat in isocaloric rations has been reported by Forbes et al. (1946) to result in a decreased heat increment in the rat, thus making available a greater proportion of the metabolizable energy for productive purposes. Forbes and Swift (1944) observed that the heat increment of a diet could not be computed from the specific dynamic ef1
Scientific Article No. A875 Contribution No. 3185 of the Maryland Agricultural Experiment Station (Department of Poultry Husbandry).
feet of each of its component parts, but varied with differences in nutrient combination. The work reported in this paper involves a study of energy utilization in the chick, using the multiple regression analysis approach in determining the energy content of ingredients in diets differing widely in carbohydrate, protein and fat levels. EXPERIMENTAL Laboratory. Two experiments were conducted, both involving four diets each of which were fed to duplicate groups of chicks maintained in electrically heated battery brooders with raised wire floors from 2 to 4 weeks of age. Feed and water were provided ad libitum. In experiment 1, Van tress X Arbor Acre crossbreed males were used, while New Hampshire X Columbian Rock crossbred chicks of both sexes were used in experiment 2. Prior to the initiation of both experiments, a larger number of day-old chicks were reared under similar conditions and fed a practical chick starter. At the end of the 13th day of this preliminary period, the chicks were fasted for 20 hours, weighed and distributed into uniform groups on the basis of body weight, discarding approximately one third of the chicks from the extreme weight ranges. Thus, in each experiment, nine groups of 14 chicks each were selected, one of which was sacrified without loss of blood for gross
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P
ENERGY UTILIZATION
TABLE 1.—Coin position of experimental chick diets Ingredients
Diet 1 Diet 2 Diet 3 Diet 4 Percent
1
Cerelose Isolated soybean Protein 2 Corn oil Glycine DL-methionine Chromic oxide DPPD 3 Proc. penicillin (50% mix) Minerals4 Vitamins5
Analysis: Metabolizable Cal./lb. Protein (NX6.25)
32.8
28.6
49.9
61.
39.8 20. 0.8 0.8 0.35 0.0125
49.6 14. 1. 1. 0.35 0.0125
34.9 8. 0.7 0.7 0.35 0.0125
30. 2. 0.6 0.6 0.35 0.0125
0.001 5.058 0.384
0.001 5.058 0.384
0.001 5.058 0.384
0.001 5.058 0.384
100.
100.
100.
100.
1867 34.0
1750 42.3
1586 29.8
1432 25.7
1 Glucose monohydrate (Cerelose); 9.4 and 9.2% moisture in experiments 1 and 2, respectively. 2 Drackett C-l assay protein; 8.9 and 8.8% moisture in experiments 1 and 2, respectively. 3 Diphenylparaphenylenediamine. 4 Minerals added, % of diet: Ca C0 3 , 0.75; Ca3 (P0 4 ) 2 , 2.3; K 2 HP0 4 , 0.8; Mg SCv 7H 2 O,0.5; NaCl, 0.6; FeS0 4 -7H 2 0, 0.05; CuS0 4 -5H 2 0, 0.002; Mn S0 4 -H 2 0, 0.031; CoSOv7H 2 0, 0.0002; Na Br, 0.002; Zn CI, 0.002; KI, 0.004; H 3 B0 3 , 0.001; A1K(S0 4 ) 2 -12H 2 0, 0.01 Na Mo0 4 -2 H 2 0, 0.001; and Na 2 S i 0 3 - 9 H 2 0 , 0.005. 5 Vitamins added, amount per 100 gms. of diet: 50 mg. vitamin A cone. (20,000 I.U./gm.), 10 gm. vitamin D 3 cone. (15,000 I.C U. gm.) 200 mg. choline chloride (100%), 3 mg. alpha-tocopheryl acetate, 3 mg. vitamin Bi 2 , 0.5 mg. menadione, 100.0 mg. inositol, 0.5 mg. paraaminobenzoic acid 0.04 mg. biotin, 0.8 mg. folacin, 1 mg. pyridoxine HC1, 5 mg. niacin, 4 mg. calcium pantothenate, 2 mg. riboflavin, 2 mg. thiamine HC1 and 2 mg. ascorbic acid.
experimental period, droppings were collected in aluminum foil. These samples were removed at least twice daily and dried in a forced air oven, ground and a uniform sample placed in a stoppered flask and stored at 5°C. until chromic oxide, nitrogen and gross energy determinations could be made. At the end of each experimental period, the chicks were again fasted for 20 hours and weighed. Then seven birds in experiment 1 and six birds in experiment 2, selected to be representative on the basis of body weight, were sacrified from each pen for gross energy and nitrogen determination. Later the carcasses were partially thawed, reweighed, and ground in a large meat grinder using a plate with % inch holes. All the sacrificed birds from each pen, including the feathers and digestive tract, were ground together and mixed thoroughly. Approximately 1 kilogram of this mixture was then placed in a one-gallon capacity Waring blendor, along with an equal weight of cold water, and blended for about 3 minutes. Then samples were removed for lyophilizing and three weighed porcelain crucibles were filled with samples for nitrogen determinations. Each porcelain crucible was placed inside the Kjeldahl flask and remained there throughout the determination. Carcass samples were lyophilized to constant weight and stored in a desiccator at 5°C. until samples were weighed for gross energy determination. Moisture determinations were made by the A.O.A.C. method on samples of cerelose and isolated soybean protein used in the diets. Two or more samples of each diet and of the feces from each of the sixteen pens were used in the determination of gross energy content, using the plain Parr bomb calorimeter, and for nitrogen determinations by the Kjeldahl method. Analysis of feces for chromic oxide was performed by the
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energy and nitrogen analysis. These were weighed and kept frozen until the analyses were performed. The four experimental rations, as given in Table 1, were formulated to contain widely different levels of corn oil, glucose monohydrate (Cerelose), and a proteinamino acid mixture composed of 96.1% isolated soybean protein (Drackett C-l Assay Protein) and 1.95% each of glycine and DL-methionine. These diets are considered to be adequate in all known required nutrients. During the last three days of the
931
932
E. H. BOSSARD AND G. F. COMBS
the following equation: b4, a4 + C = b ^ i + b2a2 + b3a3. Where b4 = Calories of net energy required daily for maintenance of 1 kilogram of body weight; a4 = No. of days of period X y2 (initial weight in kg. + final weight in kg.); C = Calories of gross energy gained in the carcass, corrected for nitrogen retention, during the period (dependent variate); bi, b2 and b3 = Calories of net energy per gram of glucose, corn oil and protein-amino acid mixture, respectively; and a ^ and a3 = grams of glucose, corn oil, and protein-amino acid mixture, respectively, eaten during the period. Calculations showed that the maintenance term could not be determined accurately by this equation due to its small range of variation. Hence, maintenance was approximated for each experiment by assuming that on the average for all diets combined, 70% of the metabolizable energy was useful as productive energy as defined by Fraps (1946). Productive energy is a net energy term uncorrected for nitrog2n retention. This arbitrary values of 70% was derived from a comparison of productive and metabolizable energy of Titus (1955). Net energy Calories used for maintenance were calculated by substracting the Calories gained in the carcass, uncorrected for nitrogen retention, from the calculated Calories of productive energy consumed for each experiment. Then the average number of kilograms of bird maintained per day was divided into the total net energy used daily for maintenance to approximate the Calories needed for maintenance per kilogram of bird per day. Calories used for maintenance plus Calories deposited in the carcass (corrected for nitrogen retention as above) by pens, gave the net energy value of each ration. This, likewise, was distributed among its energy producing ingredients by use of multiple-regression analysis to find ingredient net energy values.
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method of Bolin and Dinusson (1957). The value of 8.22 Calories per gram of nitrogen retained in the carcass was used as a correction in calcluating metabolizable energy content of each ration as suggested by Hill and Anderson (1958). Statistical. Multiple-regression analysis was used with the data from each experiment separately and with the combined data from both to determine the metabolizable energy content of each ingredient. Data obtained from each pen were fitted to an equation with the determined metabolizable energy intake and the grams of each of the three energy-supplying ingredients consumed representing that ammount associated with one gram of marker (chromic oxide) eaten. The assumptions made in the multipleregression analysis approach are that the determined nitrogen corrected metabolizable energy intake (y) for any of the diets is expressible as a linear function of the fixed variables, ai (gms. glucose eaten), a2 (gms. corn oil eaten), and a3 (gms. proteinamino acid mixture eaten); and that the residual errors are normally and independently distributed around zero with constant variance. In order that the calculated caloric value of these ingredients could be used in other "balanced" diets containing other ingredients, the equations were passed through the origin instead of inserting a floating constant b0. The multiple-regression equation used was as follows: y = Kai + b2a2 + b3a3. The values of b 1; b 2 , and b 3 were computed by the abbreviated Doolittle method for inverting a matrix (Anderson and Bancroft, 1952). The b 1 ; b 2 , and b 3 represent estimates of the metabolizable Calories per gram of glucose, corn oil, and the proteinamino acid mixture, respectively. Multiple-regression analysis to determine net energy (corrected to nitrogen equilibrium) of ingredients was attempted with
933
ENERGY UTILIZATION
Nitrogen corrected metabolizable Calories consumed, less the net energy (nitrogen corrected) intake, yielded a calculated amount of metabolizable energy used for heat increment with the different rations. Net energy values uncorrected for nitrogen retention, also were calculated for ingredients by use of multiple-regression analysis. These would be more nearly comparable to productive energy values.
TABLE 3.—Metabolizable and net energy values obtained for cerelose, corn oil and isolated soybean protein-amino acid mixture, with standard deviations1
Experiment
Cerelose
Corn oil
Drackett C-l protein plus amino acids2
Met. Cal./gm. (moisture -free basis) 1 2 1 &2
3.54 + .08 3.31 + .08 3.43 + .09
8.63 + .28 7.74 + .28 8.18 + .31
3.70+.15 4.02+.16 3.86+.18
Net. Cal.,/gin. (uncorrected for N. retention) RESULTS AND DISCUSSION
TABLE 2.—Energy values obtained for experimental diets, with standard deviation, (dry basis)1 Gross Metabolizabli^ N e t Calories Net Diet Exp. Calories/ Calories 2 / " (uncorrected Calories 2 / for N gm. gm. retention/gm.) ^m' 1
1 2
2
3
4
1
5.005 4.995
4.171 4.063
av.
5.000
4 . 1 1 7 + .066 2 . 7 8 1 + .029 2 . 5 7 1 + .023
1 2
4.823 4.830
3.868 3.946
av.
4.827
3 . 8 5 7 + .010 2 . 7 0 3 + .061 2 . 4 9 + .063
1 2
4.239 4.229
3.555 3.440
av.
4.234
3 . 4 9 8 + .072 2 . 4 7 0 + .094 2 . 2 7 1 + .076
1 2
3.750 3.774
3.163 3.148
av.
3.762
3 . 1 5 6 + .020 2 . 2 7 1 + . 0 2 4 2 . 1 0 6 + .019
2.784 2.779
2.703 2.702
2.540 2.400
2.287 2.255
2.561 2.582
2.478 2.504
2.325 2.217
2.112 2.100
Each value based on data from duplicate groups of 14 chicks each. 2 Corrected to nitrogen equilibrium.
1 &2
2.36 + .11
4.58± .39
3.07+.22
Net Cal./gm. (corrected to N. equilibrium) 1 &2
2.21 + .09
4.28 + .33
2.79+.18
1
95% confidence limits are obtained by multiplying the standard deviation by 2.776 for experiments 1 and 2 separately, and 2.179 for experiments 1 and 2 cominbed. 2 Composed of 96.1% isolated soybean protein (Drackett C-l) and 1.95% each of glycine and DLmethionine.
indicates that the multiple-regression analysis is not sufficiently accurate when three or more variables are solved simultaneously with biological data. It is not possible to eliminate entirely correlations between the variable in such experiments; hence the normal variations encountered in such data renders this approach unsatisfactory where a high degree of accuracy is desired. The calculated net energy values obtained for each diet with and without corrections to nitrogen equilibrium, also are given in Table 2. These were very reproducible with little more variation than was observed for the metabolizable energy determinations. Table 3 presents the corresponding net energy values for the diet ingredients. The same variation in values was found between experiments as was noted for metabolizable energy. The metabolizable energy values obtained for cerelose and corn oil in this study are 1556 and 3710 Calories per pound on a dry basis, respectively, using the data from both experiments. These values compare with
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The gross and metabolizable energy values obtained for the four experimental diets are given in Table 2. The metabolizable energy content of the ingredients, as obtained by multiple-regression analysis using the data from experiments 1 and 2 separately, and both combined are given in Table 3. Values of 3.54, 8.63 and 3.70 Calories per gram were obtained in experiment 1 and 3.31, 7.74 and 4.02 in experiment 2 for cerelose, corn oil and the protein-amino acid mixture, respectively. These widely different metabolizable energy values for each ingredient between experiments, with excellent agreement in the metabolizable energy values obtained for each diet
934
E. H. BOSSARD AND G. F. COMBS
Although satisfactory estimates of ingredient Caloric values may be obtained sometimes by use of multiple-regression analysis using diets containing variable amounts of three ingredients (Metta and Mitchell, 1954), the present study and that by Bernstein et al. (1956) would indicate that poor separation of the Caloric contribution of each ingredient in the diet is common. The data concerning weight gain, body composition, feed conversion and energy consumption by diets is given in Table 4. The mean gains in body weight were significantly greater (P < .01) for the chicks fed the diets containing 8 or more percent corn oil than for those receiving ration 4. The chicks which received diet 4 had a significantly higher gross energy content of
TABLE 4.—Body weight gain, body composition, feet i conversion and energy requirements as influenced by diets differing in energy source^ Diet
Exp.
Av.2 gain/gm.
Body composition3 Cal. gross % energy/gm. Moist.
1
2
3
4
1
Consumption per gram gain
Protein
%
Feed, gms.
Gross Cal.
Met. Cal.4
Net Cal. (uncor. for N. ret.) 5
Net Cal.4
1 2
300 286
1.77 1.71
68.8 69.8
20.0 19.2
1.26 1.31
6.20 6.52
5.25 5.30
3.51 3.62
3.22 3.37
av.
293
1.74
69.3
19.6
1.28
6.41
5.28
3.57
3.30
1 2
297 279
1.69 1.73
69.6 69.6
20.3 20.1
1.26 1.36
6.06 6.60
4.86 5.26
3.39 3.69
3.11 3.43
av.
288
1.71
69.6
20.2
1.31
6.33
5.06
3.54
3.27
1 2
292 281
1.77 1.73
68.4 69.2
21.1 20.5
1.38 1.53
5.85 6.50
4.91 5.28
3.51 3.71
3.21 3.43
av.
286
1.75
68.8
20.8
1.46
6.17
5.10
3.61
3.32
1 2
272 258
1.85 1.83
68.1 68.5
20.4 19.9
1.63 1.74
6.10 6.58
5.14 5.49
3.71 3.93
3.43 3.66
av.
265
1.84
68.3
20.2
1.68
6.34
5.32
3.82
3.55
Values represent averages for replicated groups of 14 chicks each. 14-28 day gain in exp. 1, 14-29 day gains in exp. 2. Initial body weights at 14 days averaged 159 and 145 grams in experiments 1 and 2, respectively. 3 Values apply to 28th and 29th day of age in experiments 1, and 2 respectively. Calories of gross energy per gram of carcass averaged 1.72 and 1.60 at 14 days in experiments 1 and 2, respectively. 4 Corrected to nitrogen balance. 6 Similar to productive energy values. 2
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1633 (Potter and Matterson, 1960) Calories per pound and 1652 (Anderson et al., 1958) for cerelose, dry basis, and with 4000 (Potter and Matterson, 1960), 4000 and 4070 (Hill and Renner, 1957), and 3838 to 3960 (Donaldson, 1957) Calories per pound for corn oil. The uncorrected net energy (productive energy) values obtained for cerelose and corn oil were 1071 and 2078 Calories per pound (dry basis), respectively. These values compare with 1271 (Anderson, 1955) and 1125 and 1506 (Anderson et al, 1958) Calories per pound for cerelose, and 2100 Calories per pound for corn oil (Fraps, 1946). Estimates of the value of fats by Hill (1956) and Titus (1955), suggest a higher productive energy value for corn oil.
935
ENERGY UTILIZATION
TABLE 5.—Nitrogen intake, retention and excretion of chicks fed diets varying in protein level and energy source1
Diet
1 2 3 4
Gms. nitrogen consumed/ % nitrogen retained in chick carcass period 20.44 25.47 19.91 18.32
46.8 38.3 51.0 49.4
% nitrogen 2 excreted 45.0 54.1 45.7 44.3
1 Each value based on data for 4 groups of 14 chicks each (both experiments). 2 Based on data collected during last 3 days of each experiment.
spectively. The differences are not significant. The percent of the metabolizable energy intake in the carcass (Table 6) was significantly greater (P < .01) for diet 4 than for diets 1 and 2. This difference appears to be inversely related to fat level with no apparent effect due to protein level. Similarly, the percent of metabolizable energy used for heat increment, as calculated, was lowest for chicks fed the low-fat diet 4 and highest for the chicks fed the 20% fat diet 1 (P < .01). A similar significant difference (P < .01) was obtained between diets 1 and 4 for percent of metabolizable Calories used as net energy (nitrogen corrected). The maintenance requirements could not be determined in these trials, but were calculated by assuming that an average of 70% of the metabolizable energy for all diets in each experiment was productive or net energy uncorrected for nitrogen retention as described above. This assumed relationship yielded maintenance requirements of 118 and 124 Calories of net energy per kilogram of body weight per day for chicks in experiments 1 and 2, respectively. In similar studies with chicks fed purified diets, Potter (1958) obtained a maintenance requirement of 121 Calories per kilogram of body weight per day, which is es-
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the carcass (P < .01) than those fed the other rations. The intake of net, but not metabolizable energy, per gram gain was correspondingly greater (P < .01) for the chicks fed diet 4 than for diet 1. The average total nitrogen intake per chick, percent of nitrogen ingested which was retained in the body during the experimental period and percent of ingested nitrogen which was excreted during the last 3 days are given in Table 5. The metabolizable Calories per pound for each percent protein were 54, 41, 53, and 54 in diets 1, 2, 3, and 4, respectively. As expected, a smaller percent of the nitrogen consumed was retained in the carcass and more was excreted by chicks fed the high-protein diet 2 than for the chicks fed the other diets (P < .01). The total nitrogen recovered ranged from 91.8 to 96.7%. The fact that nitrogen retention was based on difference in carcass content from start to finish of each experiment, while the nitrogen excretion was measured only during the last 3 days, may explain in part the incomplete recovery. These differences in nitrogen retention, as a result of differences in protein intake, show the need for adjusting net energy values as well as metabolizable energy values, for nitrogen retention if reproducible values are to be expected. The percent of gross energy metabolized and proportion of metabolizable energy used for growth, maintenance and heat increment, as influenced by energy source, are given in Table 6. The expected reduction in the percent of gross energy which was metabolizable (corrected for nitrogen retention)" for the high protein diet 2 is eliminated if the gross energy values are also corrected for nitrogen content (less 8.22 Calories per gram of nitrogen). Thus, an average of 90.4, 90.3, 91.0 and 92.2% of the nitrogen corrected gross energy was metabolized for diets 1, 2, 3, and 4, re-
936
E. H. BOSSARD AND G. F. COMBS TABLE 6.—Percent of gross energy metabolized and proportion of metabolizable energy used for growth, maintenance and heat increment by the growing chick1
Diet
Exp.
% of gross energy metabolized2
Energy retained in carcass2
Energy Energy used used for for heat 3 maintenance increment3
Net energy (uncorrected for N retained)'1
Net energy2
(As % of metabolizable energy consumed) 1
2
4
83.4 81.4
28.9 28.3
32.5 35.3
38.6 36.5
66.8 68.5
61.4 63.6
av.
82.3
28.6
33.9
37.5
67.6
62.5
1 2
80.2 79.5
28.7 29.1
35.4 36.0
35.9 34.9
69.9 70.2
64.1 65.1
av.
79.9
28.9
35.7
35.4
70.1
64.6
1 2
83.9 81.4
30.1 28.7
35.3 35.7
34.6 35.5
71.4 69.8
65.4 64.5
av.
82.6
29.4
35.5
35.1
70.6
64.9
1 2
84.4 83.5
31.8 30.8
34.9 35.9
33.3 33.3
72.3 71.7
66.7 66.7
av.
83.9
31.3
35.4
33.3
72.0
66.7
1
Each value represents average of two replicates of 14 chicks each. Corrected to nitrogen equilibrium. Based on maintenance values derived by assuming that 70% of the metabolizable energy for all diets combined in each experiment was available as productive energy (see text). 4 Similar to productive energy values. 2
3
sentially the same as that calculated herein. Furthermore, any error in the maintenance requirement values used would influence the calculated heat increment values by almost a constant amount, and would effect, little, their relative relationships. Since the growth rate was very similar, little error also is expected in relating the maintenance requirement as a direct function of body weight. The significantly lower percentage of the metabolizable energy retained in the carcass and significantly higher amount used for heat increment by the chicks fed the 20% fat diet 1 than by those fed the 2% fat diet, is noteworthy. This apparent increase in proportion of metabolizable energy used for heat increment as the level of corn oil was increased, is not in agreement with the results of Swift et al. (1959). These workers found no appreciable difference in heat production by humans fed equal amounts of protein and energy daily
but containing widely different amounts of fat. The heat loss should vary with the specific metabolic reactions and hence, the heat increment in the metabolism of fat Calories might differ if the fat is oxidized or stored as body fat. The proportion of Calories from fat to other Calories in the diet, and tendency of the animal to store fat, might influence the effect of dietary fat on heat increment. The higher gross energy content of the carcass of diet 4 fed chicks, than for chicks fed the other diets, would suggest that the body fat content was also greater. These observations suggest that dietary fat actually may increase the heat increment of a diet provided it is largely oxidized rather than stored by the chick. SUMMARY Studies on energy utilization were conducted with two to four week old chicks fed ad libitum amounts of four rations contain-
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3
1 2
ENERGY UTILIZATION
ACKNOWLEDGMENTS
The authors are indebted to Merck & Co., Inc., Rahway, N.J., for supplying procaine penicillin and crystalline vitamins; Nopco Chemical Co., Harrison, N.J., for vitamin A & D 3 supplements; Limecrest Research Laboratory, Newton, N.J., for trace minerals; E. F. Drew & Co., Inc., New York, N.Y., for corn oil; Monsanto Chemical Co., St. Louis, Mo., for glycine; E. I. duPont de Nemours & Co., Inc., Wilmington, Del., for DL-methionine; Lederle Laboratories, Pearl River, N.Y., for folacin; and Hoffman LaRoche, Inc., Nutley, N.J., for biotin used in this study. REFERENCES Anderson, D. L., 1955. Comparative studies on the determination of metabolizable and productive energy with the growing chick. Ph.D. Thesis, Cornell University. Anderson, D. L., F. W. Hill and R. Renner, 1958. Studies of the metabolizable and productive
energy of glucose for the growing chick. J. Nutrition, 65: 561-574. Anderson, R. L., and T. A. Bancroft, 1952. Statistical Theory in Research. McGraw-Hill Book Co., Inc., New York, N.Y., p. 339. Association of Official Agricultural Chemists, 1945. Methods of Analysis, 6th edition. Bernstein, L. M., M. I. Grossman, J. M. Iacono, H. J. Kizywicki, L. M. Levey and E. A. Francis, 1956. Determination of the metabolizable energy of purified foodstuffs for human subjects. U.S. Med. Nutr. Lab. Rpt. No. 193, Denver. Bolin, D. W., and W. E. Dinusson, 1957. The determination of chromic oxide in feeds and feces with perchloric acid and molybdenum used as a catalyst. Exp. Sta., Fargo, N.D. (Mimeo). Donaldson, W. E., 1957. Studies on the mechanisms of fat utilization and appetite in chickens and turkeys. Ph.D. Thesis, U. of Maryland. Forbes, E. B., and R. W. Swift, 1944. Associative dynamic effects of protein, carbohydrate and fat. J. Nutrition, 27: 453-468. (Also see Nutr. Rev. 3 : 83, 1945). Forbes, E. B., R. W. Swift, W. H. James, J. W. Bratzler and A. Black, 1946. Further experiments on the relation of fat to economy of food utilization. J. Nutrition, 32: 387-396. Fraps, G. S., 1946. Composition and productive energy of poultry feeds and rations. Texas Agr. Exp. Sta. Bull. No. 678. Hill, F. W., 1956. Studies of the energy requirements of chickens. 4. Evidence for a linear relationship between dietary productive energy level and the efficiency of egg production. Poultry Sci. 35: 59-63. Hill, F. W., and D. L. Anderson, 1958. Comparison of metabolizable energy and productive energy determinations with growing chicks. J. Nutrition, 64: 587-603. Hill, F. W., and R. Renner, 1957. Metabolizable energy values of feedstuffs for poultry and their use in formulation of rations. Pro. 1957 Cornell Nutrition Conf. for Feed Mfg., pp. 22-32. Metta, V. C , and H. H. Mitchell, 1954. Determination of the metabolizable energy of organic nutients for rats. J. Nutrition, 52 : 601-610. Potter, L. M., 1958. Evaluation of alpha cellulose for its metabolizable and productive energy and a comparison of methods of determining metabolizable energy in the chick. Ph.D. Thesis, Connecticut (Storrs). Potter, L. M., and L. D. Matterson, 1960. The metabolizable energy for feed ingredients for chickens. Connecticut (Storrs) Agr. Exp. Sta. Prog. Rpt. No. 39. Titus, H. W., 1955. The Scientific Feeding of Chick-
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ing widely varying levels of glucose (cerelose), corn oil and soybean protein plus amino acids. Chicks which received a lowfat diet (2 % corn oil), showed slightly lower gains in weight, higher gross energy content per gram of carcass gain, greater retention of metabolizable energy in the carcass and less heat increment as a percentage of metabolizable energy intake than chicks fed a ration containing 20% corn oil. No measurable differences in heat increment or carcass composition were attributed specifically to the carbohydrate or protein level of the rations. Multiple-regression analysis was used to determine estimates of metabolizable and net energy values of the three ingredients. Limited success was obtained by this method due to biological variation, linear correlation among levels of ingredients in rations and possible variation in metabolizable energy value of each ingredient according to amounts of the other ingredients present in the ration.
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Some Effects of Saline Waters on Chicks, Laying Hens, Poults, and Ducklings 1 Departments
L. M. KRISTA,2 C. W. CARLSON AND 0. E. OLSON of Poultry Husbandry and Station Biochemistry, South Dakota Experiment Station, Brookings, South Dakota
Agricultural
(Received for publication September 6, 1960)
L
ARGE quantities of sodium chloride, ' sodium sulfate, and magnesium sulfate render so-called saline waters unsuitable for livestock and poultry consumption. Although sodium chloride is an essential ingredient in the poultry diet, relatively small amounts are required. Selye (1943) reported excessive intakes of sodium chloride via feed or water to cause sudden mortality. He and Peterson (1943) reported 2% sodium chloride in solution to be highly toxic, whereas 2% in feed resulted only in wet litter production. As little as 0.5% salt in solution was reported toxic by Selye (1943). These findings were supported by Field and Eveans (1946) as well as by Kare and Biely (1948). The latter workers found that chicks could tolerate approximately 4% sodium chloride in feed before showing toxic effects, whereas Barlow et al. (1948) reported 3 % to be toxic. Equal toxicities were reported by Kare and Biely (1948) for 0.3% and 0.9% salt in solution as compared respectively to 0.8% and 4.13% salt in the feed. 'Approved for publication by the Director of the South Dakota Agricultural Experiment Station as Journal Series No. 492. From the senior author's M.S. degree thesis. 2 Present address: University of Minnesota, St. Paul.
According to Blaxland (1946), Selye (1943), Quigley and Waite (1932), and Kare and Biely (1948) older chickens are more resistant to salt toxicity than baby chicks, with various individuals within classes showing marked differences in tolerance to salt. Scrivner (1946) found that 1% sodium chloride in the feed for turkey poults was without effect, whereas 1% in water resulted in 100% mortality, with edema and ascites. Sodium chloride at 2 % in the water produced stupor within 48 hours; however, edema and ascites were not evident at the time of death. At 2% in the feed, half of the poults showed edema and ascites. Matterson et al. (1946) reported that poults could tolerate up to 2% sodium chloride in a semi-purified salt-free diet similar to the results reported by Batchelder (1946). James (1946) reported no adverse effects of 1% sodium chloride in the feed, whereas 2% increased water consumption and decreased feed consumption and rate of gain. The results of studies on the effects of graded levels of salt solutions for chicks, laying hens, turkey poults, and ducklings will be presented herewith. CHICKS
Procedure. Two experiments were conducted using day-old Single Comb White Leghorn chicks which were wing banded,
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INTRODUCTION