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Effect of Antibiotic Supplements to Diets Containing Rye on Chick Growth1
1130
F. G. PROUDFOOT, W. F. LAMOREUX AND J. R. AITKEN
REFERENCES Dean, P., W. F. Lamoreux, J. R. Aitken and F. G. Proudfoot, 1969. Flavor associated with fish meal in diets fed to broiler chickens. Can. J. Animal Sci. 49: 11-15. Dean, P., F. G. Proudfoot and J. R. Aitken, 1971. The effect of diets containing white fish meal on acceptability and flavor intensity of roasted broiler chickens. Can. J. Animal Sci. 51: 15-20. Hardin, J. O., J. L. Milligan and V. D. Sidwell, 1964. The influence of solvent extracted fish meal and stabilized fish oil in broiler rations on performance and on the flavor of broiler meat. Poultry Sci. 43 : 858-860. Merritt, E. S., 1962. Note on linear trends in broiler weights and measurements taken over a 10-hour period. Can. J. Animal Sci. 42: 252253.
Nesheim, M. C , 1966. Genetic variation in nutrient requirements. World's Poultry Sci. J. 22: 290-298. Scott, H. M., W. F. Dean, A. Aguilera and R. E. Smith, 1962. Quality of fish meal in relation to its value as a supplement to corn-soybean oil meal chick diets. Poultry Sci. 4 1 : 1681. Smith, R. E., and H. W. R. Chancey, 1967. Laying rations based on wheat, oats and fish meal. Poultry Sci. 46 : 1438-1442. Steele, R. G. D., and J. H. Torrie, 1960. Principles and Procedures of Statistics. McGraw Hill Book Co., New York. Waldroup, P. W., P. van Walleghem, J. L. Fry, C. Chicco and R. H. Harms, 1965. Fish meal studies. 1. Effects of levels and sources on broiler growth rate and feed efficiency. Poultry Sci. 44: 1012-1016.
Effect of Antibiotic Supplements to Diets Containing Rye on Chick Growth1 TOMAS MACAULIFFE AND JAMES MCGINNIS Department of Animal Sciences, Washington State University, Pullman, Washington 99163 (Received for publication December 29, 1970)
T
HE results of experiments in which rye has been used to replace other cereal grains of the diet have usually shown rye to have a very low nutritional value. Growth of chicks fed high levels of rye is generally greatly depressed and the droppings of chicks are very abnormal. Efforts to improve the nutritional value of rye have met with only limited success. Fry et al. (1958) showed that a water treatment involving the wetting of ground rye with an equal weight of water and followed by drying in an oven at 70° C. gave a significant improvement in chick growth. This treatment did not, however, increase chick growth to levels obtained with other cereal grains such as corn or barley. Smith and 'Scientific Paper No. 3589, Project 1922, College of Agriculture, Washington State University, Pullman.
Mclntire (1960) failed to obtain an improvement in chick growth by water treating rye. Moran et al. (1969) have recently reviewed the literature on the value of rye as a cereal grain for chicks and published the results of additional experiments using rye as a dietary component in the diet. Additions of fermentation enzyme supplements did not improve the feeding value of rye and in their studies addition of a mixture of four antibiotics totaling 8.8 mg. of antibiotic per kilo of diet failed to give a growth increase. This antibiotic mixture contained equal parts of penicillin, tylosin, chlortetracycline and oleandomycin. Adams and Naber (1969) found that water treating wheat or barley with a dilute acid solution (0.1 N HC1) improved their nutritional value. When 0.2 N HC1 was used no improvement resulted. They also reported that antibiotic supplementa-
ANTIBIOTICS AND RYE
tion of diets containing different cereal grains have significant improvements in chick growth where water treatment of the grain had little or no effect. Moran et al. (1970) reported that rye could be fed to chicks at levels up to 25 percent of the grain component without a depressing effect on growth and feed efficiency. Higher levels depressed both growth and feed conversion. This observation suggests that rye either contains a toxic component or that it affects chick growth adversely in an indirect manner possibly by influencing the intestinal microorganisms. Because of this suggestion. additional experiments were conducted in our laboratories to study the influence of level of substitution of rye for glucose in a test diet on its metabolizable energy value. Studies were also made to determine whether an improvement in the nutritional value of rye by water treatment could be repeated and whether or not other dietary supplements such as enzymes and antibiotics would influence growth and feed efficiency of chicks fed diets containing rye. The results of these studies are reported in this paper. METHODS AND MATERIALS
All studies were conducted with chicks from a mating of White Rock females X White Mountain males obtained from Hubbard Farms. Three replicate groups of ten chicks were fed each experimental diet. Sex of chicks is indicated for each experiment. The chicks were maintained from hatching to termination of the studies in electrically heated battery brooders with raised screen floors. Feed and water were provided ad libitum and 14 hours of light were given daily. The chicks were group weighed at weekly intervals unless otherwise noted and feed consumption by each group was determined at the time of weighing the chicks.
1131
The data were analyzed by analysis of variance (Snedecor, 1956) and the significance of differences among treatments was determined using Duncan's multiple range test (1955). Additional details are given for each of the different experiments. Experiment 1.—Metabolizable energy. The procedure of Hill and Anderson (1958) with some minor modifications was used to determine the effect of level of substitution of rye for glucose on the metabolizable energy (M.E.) value obtained for this grain. The diet composition was modified by replacing fish solubles and menhaden fish meal with herring fish meal and dried whey with a dried whey product. Chicks of both sexes were used in the study and body weight gain was determined for the period after the chicks were placed on the different diets to four weeks of age. The reference diet of Hill and Anderson as modified was fed to all chicks for a 2-week period, at which time appropriate groups were changed to the diets containing different levels of rye. The levels of rye used were 10, 20 and 40%. The grain replaced equal amounts of glucose. Experiment 2. Composition of the basal diet in which Gaines wheat, rye or rye subjected to different treatment was used in equal amounts is given in Table 1. The rye was water treated by adding an equal weight of water to the ground grain, spreading on stainless steel trays at a depth of approximately 25 mm. and drying in a forced draft electric oven at 70°C. When rye was autoclaved it was mixed with water as above, spread in metal trays, autoclaved 15 minutes at 121°C. and dried in the oven as in the water treatment procedure. A fermentation-produced enzyme product obtained from Takamine Laboratories, Clifton, N. J. and designated HT-44A was
1132
T. MACAULIFFE AND J. MCGINNIS TABLE 1.—Composition 0} basal diet Ingredient 1
Cereal grain Soybean meal, dehulled Herring fish meal Meat and bone meal Dried whey product Dehydrated alfalfa Salt Animal fat Dicalcium phosphate Limestone Vitamin premix2 Trace mineral premix3 DL Methionine
Percent 55.0 27.0 5.0 5.0 1.0 1.25 0.22 4.0 0.5 0.67 0.25 0.05 0.06 100.00
The level of substitution of rye into the reference diet has a significant effect on the metabolizable energy value of this grain. The difference between the 10 and 20% level of substitution was not significant. It can also be seen that feeding rye at levels of 20 and 40% for two-week periods caused growth depression. These results suggest that rye at the 40% level of substitution either interfered with digestion of other dietary components or stimulated growth of intestinal microorganisms that utilize dietary nutrients.
1
The cereal grain was composed of wheat, rye or treated rye. 2 The vitamin premix supplied the following per kg. of diet: vitamin A, 5,500 I.U.; vitamin D 3 , 1,650 I.C.U.; riboflavin, 3.3 mg.; Ca pantothenate, 3.3 mg.; niacin 17.6 mg.; ethoxyquin 125.8 mg.; and zinc bacitracin, 11.0 mg. 3 Trace mineral mix supplied the following per kg. of diet: Mn., 500 mg.; Fe., 50 mg.; Ca., 60 mg.; Cu., 5 mg.; Zn., 50 mg.; I., 1.5 mg.; and Co., 0.5 mg.
used at a level of 2.2 gm./kg. feed. Procaine penicillin G was added as a supplement in some treatments at a level of 50 mg./kg. feed. Only female chicks were used in this study. Experiment 3. The basal diet used in Experiment 2 was modified for this study by using a vitamin premix which did not contain an antibiotic supplement. This was done to determine whether growth of chicks fed diets containing rye would be influenced by removing the low level of zinc bacitracin from the basal diet. Three different antibiotics—zinc bacitracin, procaine penicillin G and terramycin were added at levels of 10, 50 and 100 mg./kg. of diet. Male and female chicks were used. RESULTS AND DISCUSSION
Experiment 1. The results on growth of chicks fed the reference and test diets and the M.E. values obtained for rye added at different levels are summarized in Table 2.
Experiment 2. This experiment was conducted to determine whether the improvement in rye by water treatment as previously reported by Fry et al. (1958) could be repeated and whether or not other treatments of rye or supplements would influence growth and feed efficiency of chicks. The outline of the experiment and results on chick weight and feed utilization (eighteen days of age) are shown in Table 3. Replacing wheat with rye caused a significant depression in chick growth which was completely counteracted or prevented by adding 50 p.p.m. of procaine penicillin to the diets containing rye. Water treating the rye also gave a significant growth response, but of a lower magnitude than that obtained with penicillin. The addition of the enzyme material to the diet containing either rye or water treated rye had no effect on chick growth or feed efficiency. AutoTABLE 2.—Effect of level of substitution in the reference diet on metabolizable energy of rye Level of rye
% Reference diet 10.0 20.0 40
Av. Chick Metabolizable wt. at 28 days energy of rye gm. Kcal./kg. 546 561 521 507
2951a1 3159a 2507b
1 Treatments with a different letter are significantly different from each other at 5% level.
1133
ANTIBIOTICS AND RYE
claving the wet rye prior to drying it in the oven prevented an increase in the nutritional value of rye. Experiment 3. This experiment was conducted to determine the effect of three different antibiotics added to the rye-containing diet at three levels and to determine the influence of the low level of zinc bacitracin present in all diets in Experiment 2 on the response to penicillin. The results on body weight, and feed efficiency at three weeks of age are summarized in Table 4. Penicillin addition to the diet containing rye again gave a highly significant growth improvement which statistically was equal to that obtained with a diet in which wheat was used as the cereal grain. A level of 50 p.p.m. was required for the maximum growth improvement. Terramycin gave significant growth responses at all levels of supplementation and there were no differences among the three levels. In contrast, zinc bacitracin was ineffective in improving growth at all levels. The 10 p.p.m. level of penicillin also failed to significantly improve growth but both of the higher levels significantly increased growth. Penicillin TABLE 3.—Effect of water treating rye and of supplenenting diets containing rye on chick ' \ and feed efficiency
Grain Wheat Rye Rye Rye Rye Rye Rye Rye 1
Supplement or treatment of grain None None 50 ppm procaine penicillin G 2.2 gm. enzyme product/kg Water treated Water treated -(-penicillin Water treated -(-enzyme Autoclaved, water treated
A
days gm
^. £^ck
Feed/ gain
302a1 222e
1.45 1.72
299a
1.53
226de 253cd
1.70 1.53
294ab
1.52
265bc
1.57
236cde
1.71
Treatments with a different letter are significantly different from each other at a 5% level.
TABLE 4.—Effect of type and level of antibiotic on growth and feed efficiency of chicks fed diets containing rye
Grain
Wheat Rye
Antibiotic
Level ^ c l j *
Feed/
P-P-m- wks. gm.
§am
None Pro. penicillin G
— 50
395ab> 422a
1.46 1.41
None Zn bacitracin Zn bacitracin Zn bacitracin Terramycin Terramycin Terramycin Pro. penicillin Pro. penicillin Pro. penicillin
—
309ef 296f 318def 347cde 355cd 362bc 364bc 347cde 395ab 376bc
1.67 1.78 1.64 1.63 1.59 1.62 1.61 1.62 1.57 1.55
10 50 100 10 50 100 10 50 100
1 Treatments with a different letter are significantly different at a 5% level.
was the most effective of the antibiotics in improving feed efficiency but this improvement of rye failed to make it equal to wheat for feed conversion. DISCUSSION Results of our experiments show clearly that rye has a relatively inferior nutritional value for chicks at high levels and that this effect can be largely overcome by addition of either terramycin or penicillin but not by bacitracin. The failure of Moran et al. (1969) to obtain a growth response to antibiotic supplementation was probably caused by the low levels used. The effectiveness of antibiotic supplements in improving the nutritional value of rye suggests that the low value is related to the presence of a component in rye which stimulates the growth of an adverse microflora in the intestinal tract of the chick. This possibility seems more logical than the poor utilization of pentosans in rye as suggested by Preece et al. (1952). It is entirely possible that the higher content of pentose sugars in rye (loc. cit.) may be important in stimulating the growth of harmful microorganisms in the intestinal tract. Additional
1134
T. MACAULIFFE AND J. MCGINNIS
experiments are needed to investigate the effect of rye on changes in the intestinal microflora and the influence of different antibiotics on the microflora. SUMMARY
Experiments conducted with chicks in which rye was used in the experimental diets to replace wheat showed that high levels of rye depressed chick growth and reduced the metabolizable energy value obtained for rye. Water treating the rye gave a significant improvement in chick growth and feed efficiency, but a much greater response was obtained by supplementing diets containing rye with penicillin or terramycin. Higher levels of antibiotics appear to be required when diets contain rye as a cereal grain than when other grains are used. REFERENCES Adams, O. L., and E. C. Naber, 1969. 1. The effect of water and acid treatments of corn, wheat, barley and expanded or germinated grains on chick performance. Poultry Sci. 48: 853-858.
Duncan, D. B., 1966. Multiple range and multiple F tests. Biometrics, 1 1 : 1-42. Fry, R. E., J. B. Allred, L. S. Jensen and J. McGinnis, 1958. Influence of enzyme supplementation and water treatment on the nutritive value of different grains for poults. Poultry Sci. 37: 372-375. Hill, F. W., and D. L. Anderson, 1958. Comparison of metabolizable energy and productive energy determinations with growing chicks. J. Nutrition, 64: 587-603. Moran, E. T., S. P. Lall and J. D. Summers, 1969. The feeding value of rye for growing chicks: effect of enzyme supplements, antibiotics, autoclaving and geographical area of production. Poultry Sci. 48: 939-949. Moran, E. T., S. P. Lall and J. E. Summers, 1970. Altering the proportion of rye to maize in the grain fraction of practical broiler rations: effect of live performance, litter moisture, dressing yield and carcass quality. Br. Poultry Sci. 11: 147-152. Preece, I. A., andK. McKenzie, 1952. Non-startjng polysaccharides of cereal grains. II. Distribution of water-soluble gum-like materials in cereals J. Inst. Brew. 58: 459-464. Smith, R. E., and T. M. Maclntyre, 1960. The feeding of rye to growing chickens. Can. J. Animal Sci. 40: 107-113. Snedecor, G. W., 1956. Statistical Methods, 5th edition, Iowa State College Press, Ames.
Some Factors Affecting the Biological Availability of Amino Acids in Fish Protein JOSEPH H. SOARES, JR., DAVID MILLER, NORMAN FITZ AND MARION SANDERS National Center for Fish Protein Concentrate, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, U. S. Department of Commerce, College Park, Maryland 20740 (Received for publication December 29, 1970) INTRODUCTION
I
N recent years considerable effort has been made to develop a satisfactory method of determining the biological availability of amino acids in proteins. Growth response is the most common method of evaluating the availability of amino acids. However this technique has had two major
disadvantages: the ability to evaluate only one amino acid at a time and, the tendency to overestimate availability and thus often give questionable results of greater than 100% availability. Smith and Scott (1965), Buraczewski et al. (1967), and Porter and Williams (1963) have attempted to measure avail-
F. G. PROUDFOOT, W. F. LAMOREUX AND J. R. AITKEN
REFERENCES Dean, P., W. F. Lamoreux, J. R. Aitken and F. G. Proudfoot, 1969. Flavor associated with fish meal in diets fed to broiler chickens. Can. J. Animal Sci. 49: 11-15. Dean, P., F. G. Proudfoot and J. R. Aitken, 1971. The effect of diets containing white fish meal on acceptability and flavor intensity of roasted broiler chickens. Can. J. Animal Sci. 51: 15-20. Hardin, J. O., J. L. Milligan and V. D. Sidwell, 1964. The influence of solvent extracted fish meal and stabilized fish oil in broiler rations on performance and on the flavor of broiler meat. Poultry Sci. 43 : 858-860. Merritt, E. S., 1962. Note on linear trends in broiler weights and measurements taken over a 10-hour period. Can. J. Animal Sci. 42: 252253.
Nesheim, M. C , 1966. Genetic variation in nutrient requirements. World's Poultry Sci. J. 22: 290-298. Scott, H. M., W. F. Dean, A. Aguilera and R. E. Smith, 1962. Quality of fish meal in relation to its value as a supplement to corn-soybean oil meal chick diets. Poultry Sci. 4 1 : 1681. Smith, R. E., and H. W. R. Chancey, 1967. Laying rations based on wheat, oats and fish meal. Poultry Sci. 46 : 1438-1442. Steele, R. G. D., and J. H. Torrie, 1960. Principles and Procedures of Statistics. McGraw Hill Book Co., New York. Waldroup, P. W., P. van Walleghem, J. L. Fry, C. Chicco and R. H. Harms, 1965. Fish meal studies. 1. Effects of levels and sources on broiler growth rate and feed efficiency. Poultry Sci. 44: 1012-1016.
Effect of Antibiotic Supplements to Diets Containing Rye on Chick Growth1 TOMAS MACAULIFFE AND JAMES MCGINNIS Department of Animal Sciences, Washington State University, Pullman, Washington 99163 (Received for publication December 29, 1970)
T
HE results of experiments in which rye has been used to replace other cereal grains of the diet have usually shown rye to have a very low nutritional value. Growth of chicks fed high levels of rye is generally greatly depressed and the droppings of chicks are very abnormal. Efforts to improve the nutritional value of rye have met with only limited success. Fry et al. (1958) showed that a water treatment involving the wetting of ground rye with an equal weight of water and followed by drying in an oven at 70° C. gave a significant improvement in chick growth. This treatment did not, however, increase chick growth to levels obtained with other cereal grains such as corn or barley. Smith and 'Scientific Paper No. 3589, Project 1922, College of Agriculture, Washington State University, Pullman.
Mclntire (1960) failed to obtain an improvement in chick growth by water treating rye. Moran et al. (1969) have recently reviewed the literature on the value of rye as a cereal grain for chicks and published the results of additional experiments using rye as a dietary component in the diet. Additions of fermentation enzyme supplements did not improve the feeding value of rye and in their studies addition of a mixture of four antibiotics totaling 8.8 mg. of antibiotic per kilo of diet failed to give a growth increase. This antibiotic mixture contained equal parts of penicillin, tylosin, chlortetracycline and oleandomycin. Adams and Naber (1969) found that water treating wheat or barley with a dilute acid solution (0.1 N HC1) improved their nutritional value. When 0.2 N HC1 was used no improvement resulted. They also reported that antibiotic supplementa-
ANTIBIOTICS AND RYE
tion of diets containing different cereal grains have significant improvements in chick growth where water treatment of the grain had little or no effect. Moran et al. (1970) reported that rye could be fed to chicks at levels up to 25 percent of the grain component without a depressing effect on growth and feed efficiency. Higher levels depressed both growth and feed conversion. This observation suggests that rye either contains a toxic component or that it affects chick growth adversely in an indirect manner possibly by influencing the intestinal microorganisms. Because of this suggestion. additional experiments were conducted in our laboratories to study the influence of level of substitution of rye for glucose in a test diet on its metabolizable energy value. Studies were also made to determine whether an improvement in the nutritional value of rye by water treatment could be repeated and whether or not other dietary supplements such as enzymes and antibiotics would influence growth and feed efficiency of chicks fed diets containing rye. The results of these studies are reported in this paper. METHODS AND MATERIALS
All studies were conducted with chicks from a mating of White Rock females X White Mountain males obtained from Hubbard Farms. Three replicate groups of ten chicks were fed each experimental diet. Sex of chicks is indicated for each experiment. The chicks were maintained from hatching to termination of the studies in electrically heated battery brooders with raised screen floors. Feed and water were provided ad libitum and 14 hours of light were given daily. The chicks were group weighed at weekly intervals unless otherwise noted and feed consumption by each group was determined at the time of weighing the chicks.
1131
The data were analyzed by analysis of variance (Snedecor, 1956) and the significance of differences among treatments was determined using Duncan's multiple range test (1955). Additional details are given for each of the different experiments. Experiment 1.—Metabolizable energy. The procedure of Hill and Anderson (1958) with some minor modifications was used to determine the effect of level of substitution of rye for glucose on the metabolizable energy (M.E.) value obtained for this grain. The diet composition was modified by replacing fish solubles and menhaden fish meal with herring fish meal and dried whey with a dried whey product. Chicks of both sexes were used in the study and body weight gain was determined for the period after the chicks were placed on the different diets to four weeks of age. The reference diet of Hill and Anderson as modified was fed to all chicks for a 2-week period, at which time appropriate groups were changed to the diets containing different levels of rye. The levels of rye used were 10, 20 and 40%. The grain replaced equal amounts of glucose. Experiment 2. Composition of the basal diet in which Gaines wheat, rye or rye subjected to different treatment was used in equal amounts is given in Table 1. The rye was water treated by adding an equal weight of water to the ground grain, spreading on stainless steel trays at a depth of approximately 25 mm. and drying in a forced draft electric oven at 70°C. When rye was autoclaved it was mixed with water as above, spread in metal trays, autoclaved 15 minutes at 121°C. and dried in the oven as in the water treatment procedure. A fermentation-produced enzyme product obtained from Takamine Laboratories, Clifton, N. J. and designated HT-44A was
1132
T. MACAULIFFE AND J. MCGINNIS TABLE 1.—Composition 0} basal diet Ingredient 1
Cereal grain Soybean meal, dehulled Herring fish meal Meat and bone meal Dried whey product Dehydrated alfalfa Salt Animal fat Dicalcium phosphate Limestone Vitamin premix2 Trace mineral premix3 DL Methionine
Percent 55.0 27.0 5.0 5.0 1.0 1.25 0.22 4.0 0.5 0.67 0.25 0.05 0.06 100.00
The level of substitution of rye into the reference diet has a significant effect on the metabolizable energy value of this grain. The difference between the 10 and 20% level of substitution was not significant. It can also be seen that feeding rye at levels of 20 and 40% for two-week periods caused growth depression. These results suggest that rye at the 40% level of substitution either interfered with digestion of other dietary components or stimulated growth of intestinal microorganisms that utilize dietary nutrients.
1
The cereal grain was composed of wheat, rye or treated rye. 2 The vitamin premix supplied the following per kg. of diet: vitamin A, 5,500 I.U.; vitamin D 3 , 1,650 I.C.U.; riboflavin, 3.3 mg.; Ca pantothenate, 3.3 mg.; niacin 17.6 mg.; ethoxyquin 125.8 mg.; and zinc bacitracin, 11.0 mg. 3 Trace mineral mix supplied the following per kg. of diet: Mn., 500 mg.; Fe., 50 mg.; Ca., 60 mg.; Cu., 5 mg.; Zn., 50 mg.; I., 1.5 mg.; and Co., 0.5 mg.
used at a level of 2.2 gm./kg. feed. Procaine penicillin G was added as a supplement in some treatments at a level of 50 mg./kg. feed. Only female chicks were used in this study. Experiment 3. The basal diet used in Experiment 2 was modified for this study by using a vitamin premix which did not contain an antibiotic supplement. This was done to determine whether growth of chicks fed diets containing rye would be influenced by removing the low level of zinc bacitracin from the basal diet. Three different antibiotics—zinc bacitracin, procaine penicillin G and terramycin were added at levels of 10, 50 and 100 mg./kg. of diet. Male and female chicks were used. RESULTS AND DISCUSSION
Experiment 1. The results on growth of chicks fed the reference and test diets and the M.E. values obtained for rye added at different levels are summarized in Table 2.
Experiment 2. This experiment was conducted to determine whether the improvement in rye by water treatment as previously reported by Fry et al. (1958) could be repeated and whether or not other treatments of rye or supplements would influence growth and feed efficiency of chicks. The outline of the experiment and results on chick weight and feed utilization (eighteen days of age) are shown in Table 3. Replacing wheat with rye caused a significant depression in chick growth which was completely counteracted or prevented by adding 50 p.p.m. of procaine penicillin to the diets containing rye. Water treating the rye also gave a significant growth response, but of a lower magnitude than that obtained with penicillin. The addition of the enzyme material to the diet containing either rye or water treated rye had no effect on chick growth or feed efficiency. AutoTABLE 2.—Effect of level of substitution in the reference diet on metabolizable energy of rye Level of rye
% Reference diet 10.0 20.0 40
Av. Chick Metabolizable wt. at 28 days energy of rye gm. Kcal./kg. 546 561 521 507
2951a1 3159a 2507b
1 Treatments with a different letter are significantly different from each other at 5% level.
1133
ANTIBIOTICS AND RYE
claving the wet rye prior to drying it in the oven prevented an increase in the nutritional value of rye. Experiment 3. This experiment was conducted to determine the effect of three different antibiotics added to the rye-containing diet at three levels and to determine the influence of the low level of zinc bacitracin present in all diets in Experiment 2 on the response to penicillin. The results on body weight, and feed efficiency at three weeks of age are summarized in Table 4. Penicillin addition to the diet containing rye again gave a highly significant growth improvement which statistically was equal to that obtained with a diet in which wheat was used as the cereal grain. A level of 50 p.p.m. was required for the maximum growth improvement. Terramycin gave significant growth responses at all levels of supplementation and there were no differences among the three levels. In contrast, zinc bacitracin was ineffective in improving growth at all levels. The 10 p.p.m. level of penicillin also failed to significantly improve growth but both of the higher levels significantly increased growth. Penicillin TABLE 3.—Effect of water treating rye and of supplenenting diets containing rye on chick ' \ and feed efficiency
Grain Wheat Rye Rye Rye Rye Rye Rye Rye 1
Supplement or treatment of grain None None 50 ppm procaine penicillin G 2.2 gm. enzyme product/kg Water treated Water treated -(-penicillin Water treated -(-enzyme Autoclaved, water treated
A
days gm
^. £^ck
Feed/ gain
302a1 222e
1.45 1.72
299a
1.53
226de 253cd
1.70 1.53
294ab
1.52
265bc
1.57
236cde
1.71
Treatments with a different letter are significantly different from each other at a 5% level.
TABLE 4.—Effect of type and level of antibiotic on growth and feed efficiency of chicks fed diets containing rye
Grain
Wheat Rye
Antibiotic
Level ^ c l j *
Feed/
P-P-m- wks. gm.
§am
None Pro. penicillin G
— 50
395ab> 422a
1.46 1.41
None Zn bacitracin Zn bacitracin Zn bacitracin Terramycin Terramycin Terramycin Pro. penicillin Pro. penicillin Pro. penicillin
—
309ef 296f 318def 347cde 355cd 362bc 364bc 347cde 395ab 376bc
1.67 1.78 1.64 1.63 1.59 1.62 1.61 1.62 1.57 1.55
10 50 100 10 50 100 10 50 100
1 Treatments with a different letter are significantly different at a 5% level.
was the most effective of the antibiotics in improving feed efficiency but this improvement of rye failed to make it equal to wheat for feed conversion. DISCUSSION Results of our experiments show clearly that rye has a relatively inferior nutritional value for chicks at high levels and that this effect can be largely overcome by addition of either terramycin or penicillin but not by bacitracin. The failure of Moran et al. (1969) to obtain a growth response to antibiotic supplementation was probably caused by the low levels used. The effectiveness of antibiotic supplements in improving the nutritional value of rye suggests that the low value is related to the presence of a component in rye which stimulates the growth of an adverse microflora in the intestinal tract of the chick. This possibility seems more logical than the poor utilization of pentosans in rye as suggested by Preece et al. (1952). It is entirely possible that the higher content of pentose sugars in rye (loc. cit.) may be important in stimulating the growth of harmful microorganisms in the intestinal tract. Additional
1134
T. MACAULIFFE AND J. MCGINNIS
experiments are needed to investigate the effect of rye on changes in the intestinal microflora and the influence of different antibiotics on the microflora. SUMMARY
Experiments conducted with chicks in which rye was used in the experimental diets to replace wheat showed that high levels of rye depressed chick growth and reduced the metabolizable energy value obtained for rye. Water treating the rye gave a significant improvement in chick growth and feed efficiency, but a much greater response was obtained by supplementing diets containing rye with penicillin or terramycin. Higher levels of antibiotics appear to be required when diets contain rye as a cereal grain than when other grains are used. REFERENCES Adams, O. L., and E. C. Naber, 1969. 1. The effect of water and acid treatments of corn, wheat, barley and expanded or germinated grains on chick performance. Poultry Sci. 48: 853-858.
Duncan, D. B., 1966. Multiple range and multiple F tests. Biometrics, 1 1 : 1-42. Fry, R. E., J. B. Allred, L. S. Jensen and J. McGinnis, 1958. Influence of enzyme supplementation and water treatment on the nutritive value of different grains for poults. Poultry Sci. 37: 372-375. Hill, F. W., and D. L. Anderson, 1958. Comparison of metabolizable energy and productive energy determinations with growing chicks. J. Nutrition, 64: 587-603. Moran, E. T., S. P. Lall and J. D. Summers, 1969. The feeding value of rye for growing chicks: effect of enzyme supplements, antibiotics, autoclaving and geographical area of production. Poultry Sci. 48: 939-949. Moran, E. T., S. P. Lall and J. E. Summers, 1970. Altering the proportion of rye to maize in the grain fraction of practical broiler rations: effect of live performance, litter moisture, dressing yield and carcass quality. Br. Poultry Sci. 11: 147-152. Preece, I. A., andK. McKenzie, 1952. Non-startjng polysaccharides of cereal grains. II. Distribution of water-soluble gum-like materials in cereals J. Inst. Brew. 58: 459-464. Smith, R. E., and T. M. Maclntyre, 1960. The feeding of rye to growing chickens. Can. J. Animal Sci. 40: 107-113. Snedecor, G. W., 1956. Statistical Methods, 5th edition, Iowa State College Press, Ames.
Some Factors Affecting the Biological Availability of Amino Acids in Fish Protein JOSEPH H. SOARES, JR., DAVID MILLER, NORMAN FITZ AND MARION SANDERS National Center for Fish Protein Concentrate, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, U. S. Department of Commerce, College Park, Maryland 20740 (Received for publication December 29, 1970) INTRODUCTION
I
N recent years considerable effort has been made to develop a satisfactory method of determining the biological availability of amino acids in proteins. Growth response is the most common method of evaluating the availability of amino acids. However this technique has had two major
disadvantages: the ability to evaluate only one amino acid at a time and, the tendency to overestimate availability and thus often give questionable results of greater than 100% availability. Smith and Scott (1965), Buraczewski et al. (1967), and Porter and Williams (1963) have attempted to measure avail-