790
RESEARCH NOTES
from brood to brood, this sudden and usually relatively high mortality for a short period of time and its characteristic curve can often be important. When used with clinical manifestations and, with or without the lesions of the disease, it can be
a valuable tool in the diagnosis of the disease. REFERENCE Cosgrove, A. S., 1962. An apparently new disease of chickens—avian nephrosis. Avian Diseases, 6: 38S-389.
T H E USE OF G R O U N D CAROBS I N C H I C K E N D I E T S
(Received for publication February 10, 1964)
The carob tree {Ceralonia siliqud) thrives on semiarid regions of Mediterranean countries and is a valuable source of locust gum which is separated from its seeds. The average composition of carob pods is as follows (Binder et al., 1959): total sugar as glucose, 4 3 . 3 % ; crude protein, 4 . 6 % ; crude fat, 0.7%; pectin, 1.43%; fiber, 7.2%; and ash, 1.95%. Various a t t e m p t s have been made to use seedfree ground carob pods for feeding chickens. When levels of 5 % to 4 0 % of ground carobs are used to replace an equivalent amount of cereals, a marked depression in the growth of chickens has been observed (Kratzer and Williams, 1951; Vlachakis, 1959; Bornstein et al., 1963). The autoclaving of the carobs overcame this growth inhibition only to a slight extent in some reports (Kratzer and Williams, 1951; Valachakis, 1959) b u t failed in other cases (Bornstein et al., 1963). Contrary to the observations of Vlachakis (1959), Bornstein et al. (1963) feel t h a t tannin-like compounds present in carobs m a y be responsible for this inhibition in chicken growth. Digestible nutrients are as low as 5 7 % in carobs (Bondi and Meyer, 1944). I t is growth feeding ficiency
speculated t h a t a p a r t of the depression of chickens by the of carobs m a y be due to a deof available energy in the earlier
studies. If we consider about 4 kcal./gm. as the metabolizable energy of sugars and proteins, the average energy of carobs would calculate to be about 2 kcal./gm. The present experiments were designed to provide approximately equivalent levels of energy in the control and the test diets, the compositions of which are listed in Table 1. These diets were fed to day-old Arbor-Acre, broiler type chickens housed in electrically heated b a t t e r y cages. Each group contained ten birds which were weighed two times each week. The results of these experiments (Table 2) confirm our feeling t h a t diets containing carobs have a deficiency of energy. If the diets contained 5 % or 1 0 % soybean oil along with 2 0 % carob, the growth of chickens was as good as on the control diets containing ground corn. The addition of soybean oil tends to improve the gain in body weight for every gram of feed consumed. There was very little difference in the pancreas weights in mg. per 100 gm. body weight of the chickens of the various groups. The amount of locust gum present in ground carobs must be very small because the addition of 0 . 1 % Cellulase-100 to the chicken diets, or the use of carobs which have been reacted with this amount of enzyme in vitro did not improve the
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P E A N VOHRA AND F. H. K B A T Z E E Department of Poultry Husbandry, University of California, Davis
791
RESEARCH NOTES TABLE 1.—Composition of the diets Carob experimental
Control Ingredient
Metabolizable energy, kcal./lOO gm. (calc.) Protein, %
2 High fat
3 Low fat
4 High fat
5 High carob
gm. 69 15
gm. 56.7 17.3
gm. 41.7 17.3 20.0 5.0 9.0
gm. 36.7 17.3 20.0 10.0 9.0
gm. 0.0 22 48.7 13.3 9.0
—
—
—
— —
—
6.85 9.0 3.15 2.7 1.5 1.2 1.2 0.4
9.0
—
2.7 1.5 1.2 1.2 0.4
2.7 1.5 1.2 1.2 0.4
2.7 1.5 1.2 1.2 0.4
2.7 1.5 1.2 1.2 0.4
100.0
100.0
100.0
100.0
100.0
336 19.7
357 19.8
323 19.4
349 19.0
289 19.4
* Provides in mg., niacin, 8; calcium pantothenate, 4; pyridoxine hydrochloride, 2; riboflavin, 1; thiamine hydrochloride, 1; folacin, 0.3; menadione, 0.3; biotin, 0.04; vitamin B12, 0.005; choline chloride (25%), 800; vitamin A (dry, 10,000 I.U. per gm.), 100; vitamin D 3 (dry, 1,500 units per gm.), 100; vitamin E (dry, 33 units per gm.), 100. t Contains manganese sulfate, 0.025 gm.
growth of chickens beyond that caused by the addition of 5% soybean oil to the diet along with 20% carobs. This enzyme breaks down locust gum and should help in overcoming any growth inhibition in chickens due to the presence of this gum. When the diet contained about 49% ground carobs, the energy content of the
diet could not be balanced by the addition of 13% soybean oil even when all the corn has been eliminated from the diet. This is reflected in the poor growth of chickens on such diets. Four birds in one experiment exhibited a proventriculus abnormality similar to one described by O'Dell et al. (1959).
TABLE 2.—Relative growth (R.G.), feed/gain {F/G), and milligrams pancreas weight per 100 gram body weight (P/B.W.) of chickens fed ground carobs Experiment 1 Diet R.G. 1. 2. 3. 4. 5. 6. 7.
Control, low fat Control, high fat Carob, 20%, low fat Carob, 20%, high fat Carob, 49% Diet 3 + 0 . 1 % Cellulase--100* Diet 3 but 20% carob reacted with 0.1% Cellulase-100
Actual weight, gm. Duration of trial, days
F/G 12 days
100 118.2 107.6 116.5 89.2 107.6
2.27 1.80 2.03 2.05 2.74 2.07
—
—
247 23
* Kindly supplied by Miles Chemical Co., Clifton, N. J.
Experiment 2 R.G.
F/G 7 days
382 340 380
100 111.4 104.0 106.2 74.5
1.75 1.63 1.93 1.83 2.49
— —
93.5
P/B.W. 378
—
—
325 20
—
1.73
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Corn, ground Soybean meal, 44% protein Ground carob Soybean oil Fish meal Cellulose Alfalfa meal CaCOs Dicalcium phosphate Vitamin mix* Saltt
1 Low fat
792
RESEARCH NOTES
In summary, it may be concluded that part of the inhibition in the growth of chickens when ground carobs are used in their diets is due to a deficiency of metabolizable energy of this product. Along with fats, carobs can be successfully used at a 20% level in chicken rations in those areas where there is a shortage of cereals. Binder, R. J., J. E. Coit, K. T. Williams and J. E. Brekke, 1959. Carob varieties and compositions. Food Tech. 13:1213-1216.
THE EFFECT OF DIETARY PROTEIN RESTRICTION OF LAYING HENS ON SUBSEQUENT PERFORMANCE 1 P. W. WALDROUP AND R. H. HARMS Florida Agricultural Experiment Stations, Gainesville, Florida (Received for publication February 17, 1964)
Waldroup and Harms (1962) have demonstrated that low dietary protein levels during the growing period delayed sexual maturity of egg production type pullets but had no effect on subsequent rate of lay when the pullets were placed on a normal layer diet. Subsequent studies (Harms and Waldroup, 1963) indicated that low dietary protein levels during the laying period significantly lowered rate of egg production. This study was designed to study the influence of dietary protein restriction during the initial phase of the laying period on subsequent performance of laying hens on diets containing adequate protein. EXPERIMENTAL PROCEDURE Commercial egg production type pullets were reared in confinement and full fed a 1 Florida Agricultural Experiment Stations Journal Series 1856.
starter diet containing 22% protein and 920 Calories of productive energy per pound until eight weeks of age. From eight until 22 weeks of age a diet containing 16 percent protein and 940 Calories of productive energy was fed ad libitum. At 22 weeks of age the pullets were examined and normal healthy pullets were selected for use in this study and were randomly alloted into individual laying cages. Three treatment groups were used. The first group served as the positive control and were fed a 17 percent protein diet (Diet 1, Table 1) throughout the experiment. The second group was fed a 9 percent protein diet (Diet 2, Table 1) for 16 weeks and then changed to the 17 percent diet for the remainder of the test. The third group was fed the 9 percent protein diet for 32 weeks and then changed to the 17 percent protein diet. Four pens of five hens each were assigned to each treatment group. Rate of egg production on a henday basis was determined for 366 days.
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REFERENCES
Bondi, A., and H. Meyer, 1944. Digestibility trials with poultry. The digestibility of dura, carobs and hide-fleshing. J. Agric. Sci. 34: 118-122. Bornstein, S., E. Alumot, S. Mokadi, E. Nachtomi and U. Nahari, 1963. Trials for improving the nutritional value of carobs for chicks. The Israel J. Agric. Res. 13:25-35. Kratzer, F. H., and D. E. Williams, 1951. The value of ground carobs in rations for chicks. Poultry Sci. 30:148-150. O'Dell, B. L., P. M. Newberne and J. E. Savage, 1959. An abnormality of the proventriculus caused by feed texture. Poultry Sci. 38: 296-301. Vlachakis, C. J., 1959. The value of carobs in poultry nutrition. M.S. thesis, University of California, Davis, Calif.