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Effect of Flavomycin and 3-Nitro-10 on Broiler Pigmentation When Used With Different Coccidiostats
Effect of Flavomycin and 3-Nitro-10 on Broiler Pigmentation When Used With Different Coccidiostats 2. C L O P I D O L 1 J A C K L . F R Y 2 AND R. H .
HARMS
Department of Poultry Science, Florida Agricultural Experiment Stations, Gainesville, Florida 32611 AND M. W . MOELLER AND H . F . KLING Hoechst-Roussel Pharmaceuticals Inc., Somerville, New Jersey 08876
ABSTRACT In the second of a series of evaluations of Flavomycin and 3-Nitro-10 on broiler pigmentation in the presence of different coccidiostats, Clopidol was used at a level of 0.0125% in all diets. Flavomycin was included in the feed at 0, 1, 2 and 4 mg./kg. and 3-Nitro-10 was added at levels of 0, 25.0, 37.5 and 50.0 mg./kg. The broilers were grown at five different Agricultural Experiment Stations. Shank pigmentation evaluations were made with a. reflectance colorimeter. The data thus obtained (dominant wavelength, excitation purity and luminosity) represent the hue, intensity and brightness of the shank sample, respectively. In four of five experiments significant pigmentation responses were noted for Flavomycin and for 3-Nitro-10 fed in graded levels in the presence of Clopidol. Flavomycin produced significant increases in excitation purity (EP) in three experiments and in dominant wavelength (DWL) in one experiment. Significant responses in EP were produced by 3-Nitro-10 in two experiments and in DWL in two experiments. The pigmentation responses resulting from these two additives generally follow the production responses of body weight and feed efficiency to Flavomycin and 3-Nitro-10. POULTRY SCIENCE 55: 1112-1116, 1976
INTRODUCTION
T
HIS study was the second of a series in which graded levels of an arsenical, 3-Nitro-10, and an antibiotic, Flavomycin, 3 were evaluated for their effects on broiler shank pigmentation when used with different coccidiostats. Pertinent literature was reviewed in the first paper (fry et al., 1976). In the study reported herein, Clopidol 4 was the coccidiostat used. MATERIALS AND METHODS Broilers were grown in five separate loca-
1. Florida Agr. Exp. Stas. Journal Series No. 6077. 2. Currently Assistant Dean for Resident Instruction, College of Agriculture, University of Florida, Gainesville, FL 32611. 3. Registered TM of Hoechst AG; also referred to as Moenomycin and Bambermycins. 4. Coyden25, The Dow Chen.ical Co., Midland, Mich. 48641.
tions in the facilities of the Poultry Science Department of the Agricultural Experiment Station of Florida (Exp. 1), Colorado (Exp. 2), Virginia (Exp. 3), Mississippi (Exp. 4), and Alabama (Exp. 5). Production data for these experiments were presented in the paper by Kling et al. (1976). Cobb x Cobb, Indian River cross, Cobb color sex, Cobb x Cobb, and Cobb color sex chicks were used at the five locations, respectively. Commercial-type broiler diets commonly used in each of the experimental locations were utilized in this study; no effort was made to standardize the xanthophyll levels in the different diets. All diets contained 0.0125% Clopidol. A 4 x 4 factorial arrangement of treatments was utilized with Flavomycin at levels of 0, 1,2 and 4 mg./kg. and 3-Nitro-10 at levels of 0, 25.0, 37.5 and 50.0 mg./kg. Shank pigmentation sampling and analyses were as described by Fry et al. (1976) except as follows. Twelve males and twelve females
1112
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 29, 2015
(Received for publication September 29, 1975)
BROILER PIGMENTATION
were selected from each treatment, from either three or four pen replications, at each location. The selections were random except that if a bird with dark or green shanks was caught, it was released and a replacement selected. This procedure was utilized due to the problems resulting in the evaluation of pigmentation of dark or green shanks (Fry and Harms, 1973).
^ « § S ji .a 2 2 % f>
c
c
'3
:-.
The data for DWL and EP are reported by Flavomycin and 3-Nitro-10 levels for Exp. 1, Exp. 2, Exp. 3, Exp. 4 and Exp. 5 in Tables 1, 2, 3, 4 and 5, respectively. The luminosity values tended to be negatively correlated with DWL and EP but, because
| 5 ^, .a J> "§ •a
of greater bird-to-bird variation than noted
g
in the other two parameters, was generally not significantly affected by either Flavomycin or 3-Nitro-10 in the diet. The females had lower luminosity and DWL values than the males in all five experiments; this was due no doubt to the tendency for females to have a higher incidence of dark or green shanks and occurred in spite of the efforts not to select such birds for evaluation. EP values were significantly higher for females in two experiments and significantly lower for females in one experiment. The only significant interaction noted in the entire study was a sex x Flavomycin interaction (P < 0.01) for DWL in Exp. 5. In Exp. 1 (Florida), 3-Nitro-10 significantly affected both DWL and EP of broiler shanks (Table 1). The 50.0 mg./kg. level produced the highest hue (DWL); however, the DWL of shanks of birds receiving no 3-Nitro-10 did not differ significantly from that of shanks of birds receiving any of the supplemental levels of this additive. The EP of the shanks of birds receiving no 3-Nitro-10 was significantly lower than those of birds receiving any of the three levels of this additive. Dietary Flavomycin did not affect shank DWL but
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00
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Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 29, 2015
RESULTS AND DISCUSSION
Av. 578.34 578.07 578.23 578.24 578.22 0 58.05 59.06 61.88 61.78 60.20
Flav 1 59. 60.7 60. 58. 59.
DWL (nm.) Flavomycin (mg./kg.) 3-Nitro-10 4 1 2 (mg./kg.) 0 00.0 579.27 579.31 579.02 578.92 25.0 579.12 579.12 579.29 579.67 37.5 579.27 579.46 578.96 579.00 50.0 579.30 578.91 579.17 579.07 Av. 579.24 579.21 579.11 579.16 'Flavomycin means without common letters are significantly different
Flavo 0 1 579.13 62.26 62.6 579.30 60.45 64.2 579.17 62.08 64.5 579.11 61.61 62.0 579.18 61.60a 63.3 (P < 0.05). No differences due Av.
TABLE 3.—Shank dominant wavelength (DWL) and excitation purity (EP) of broilers fed graded levels of Clopidol (Exp. 3—Virginia)
3-Nitro-10 4 (mg. /kg.) 0 1 2 00.0 578.43 578.60 578.08 578.24 25.0 578.15 578.21 577.91 578.00 37.5 578.10 578.41 578.23 578.17 50.0 578.24 578.31 578.43 578.00 Av. 578.23 578.38 578.16 578.10 ' N o significant differences due to Flavomycin or 3-Nitro-10.
DWL(nm.)' Flavomycin (mg. /kg.)
TABLE 2.—Shank dominant wavelength (DWL) and excitation purity (EP) of broilers fed graded levels of Clopidol (Exp. 2—Colorado)
rom http://ps.oxfordjournals.org/ at North Dakota State University on May 29, 2015
0 52.70 53.18 56.93 54.50 54.34c 53.3 53.9 57.7 56.1 55.3
Flav 1
1
578.50 578.25 578.07 578.73 578.39cd
0
578.29 578.25 578.21 578.59 578.33c
578.56 578.58 578.52 578.33 578.50cd
578.25 578.58 578.43 578.98 578.56d
Av.
578.40a 578.42a 578.31a 578.66b 578.45 'Flavomycin means without common letters are significantly different (P < 0.05). 2 3-Nitro-10 means without common letters are significantly different (P < 0.05).
3-Nitro-10 (mg./kg.) 00.0 25.0 37.5 50.0 Av.
D W L ' 2 (nm.) Flavomycin (mg./kg.)
0 61.36 61.13 62.56 60.88 61.49
62 63 61 65 63
1
Flav
TABLE 5.—Shank dominant wavelength (DWL) and excitation purity (EP) of broilers fed graded levels o Clopidol (Exp. 5—Alabama)
0 4 Av. 578.41 578.22 00.0 578.26 578.98 25.0 578.57 578.47 578.24 37.5 578.41 577.91 578.32 50.0 578.42 578.43 578.44 Av. 578.39 578.33 'Flavomycin means without common letters are significantly different (P < 0.05). 2 3-Nitro-10 means without common letters are significantly different (P < 0.05).
3-Nitro-10 (mg./kg.)
DWL (nm.) Flavomycin (mg./kg.) 1 2 577.88 578.54 577.70 578.61 578.71 578.77 578.68 578.23 578.24 578.54
TABLE 4.—Shank dominant wavelength (DWL) and excitation purity (EP) of broilers fed graded levels of Clopidol (Exp. 4—Mississippi)
from http://ps.oxfordjournals.org/ at North Dakota State University on May 29, 2015
1116
J. L. FRY, R. H. HARMS, M. W. MOELLER AND H. F. KLING
In the birds grown in Alabama, both Flavomycin and 3-Nitro-10 resulted in significant increases in body weight (Kling et al., 1976). Likewise both of these additives produced significant increases in shank DWL (Table
5). The DWL values for the birds receiving 50.0 mg./kg. 3-Nitro-10 were significantly higher than those of the 0.0, 25.0 and 37.5 mg./kg. levels. Flavomycin at 4 mg./kg. produced DWL responses significantly higher than in birds receiving no Flavomycin. The responses to the two additives on EP approached significance at the P < .05 level. The addition of Flavomycin to the diet of broilers resulted in significantly increasing EP of shanks in three of five experiments. The addition of 3-Nitro-10 to the diet resulted in significantly increasing EP of shanks in two experiments and a numerical increase in the third. No explanation can be given for the lack of response to the additives at certain locations. These increases in shank EP would be of commercial importance since an increase of 1.0% in excitation purity is equivalent to an increase of slightly more than 1 gram of xanthophyl per ton of feed. This relationship is based upon the observations of Herrick et al. (1972) who reported that one gram of Beta-apo-8' carotenoic acid ethyl ester resulted in a 1.0% improvement in shank excitation purity.
REFERENCES Fry, J. L., and R. H. Harms, 1973. Relationship of yellow and "green" or dark shanks to skin color and pigmentation evaluation of broilers. Poultry Sci. 52: 1986-1988. Fry, J. L., R. H. Harms and M. W. Moeller, 1976. Effect of Flavomycin and 3-Nitro-10 on broiler pigmentation when used with different coccidiostats. 1. Amprol Hi-E. Poultry Sci. 55: 744-748. Herrick, G. M., J. L. Fry and R. H. Harms, 1972. The use of Beta-Apo-8-carotenoic acid ethyl ester as a standard for determination of xanthophyll utilization from natural sources by broilers. Poultry Sci. 51:428-435. Kling, H. F., M. W. Moeller, B. L. Damron, R. H. Harms, C. L. Quarles, L. M. Potter, W. L. Beane, B. C. Dilworth, E. J. Day and S. A. Edgar, 1976. Response to Flavomycin and 3-Nitro in broiler chicken diets containing Clopidol. Poultry Sci. 55: 694-699.
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 29, 2015
the addition of Flavomycin at any of the three levels produced shank EP (intensity) significantly higher than that of the birds receiving no Flavomycin. In the evaluation of the production responses (Kling et al., 1976), Flavomycin and 3-Nitro-10 both significantly increased broiler body weights. Flavomycin produced significant improvements in both body weight and feed efficiency of the broilers grown at the Colorado Experiment Station (Kling et al., 1976). Yet in the evaluation of the pigmentation of these birds (Table 2) neither Flavomycin nor 3-Nitro-10 resulted in significant effects on shank DWL and EP although the increases attributable to 3-Nitro-10 approached significance. In Exp. 3 (Virginia), Flavomycin significantly affected EP values (Table 3). The shanks of birds receiving no Flavomycin were significantly less pigmented than those of birds receiving any of the three levels of Flavomycin. The shanks of birds receiving 2 mg./kg. of Flavomycin did not differ significantly from those receiving 1 or 4 mg. /kg. but the latter two levels produced significantly different EP values. Flavomycin also significantly improved feed efficiency of these broilers (Kling et al., 1976). Although both Flavomycin and 3-Nitro-10 produced significant shank EP responses in the birds grown in Mississippi (Table 4), the only significant production response was that of 3-Nitro-10 on body weight (Kling et al., 1976). The highest shank EP value produced by 3-Nitro-10 was that of the 37.5 mg./kg. level. This level did not differ significantly from that of the 50.0 mg./kg. level but was significantly higher than the 0.0 and 25.0 mg./kg. levels. The highest level of Flavomycin produced the highest average shank EP.
HARMS
Department of Poultry Science, Florida Agricultural Experiment Stations, Gainesville, Florida 32611 AND M. W . MOELLER AND H . F . KLING Hoechst-Roussel Pharmaceuticals Inc., Somerville, New Jersey 08876
ABSTRACT In the second of a series of evaluations of Flavomycin and 3-Nitro-10 on broiler pigmentation in the presence of different coccidiostats, Clopidol was used at a level of 0.0125% in all diets. Flavomycin was included in the feed at 0, 1, 2 and 4 mg./kg. and 3-Nitro-10 was added at levels of 0, 25.0, 37.5 and 50.0 mg./kg. The broilers were grown at five different Agricultural Experiment Stations. Shank pigmentation evaluations were made with a. reflectance colorimeter. The data thus obtained (dominant wavelength, excitation purity and luminosity) represent the hue, intensity and brightness of the shank sample, respectively. In four of five experiments significant pigmentation responses were noted for Flavomycin and for 3-Nitro-10 fed in graded levels in the presence of Clopidol. Flavomycin produced significant increases in excitation purity (EP) in three experiments and in dominant wavelength (DWL) in one experiment. Significant responses in EP were produced by 3-Nitro-10 in two experiments and in DWL in two experiments. The pigmentation responses resulting from these two additives generally follow the production responses of body weight and feed efficiency to Flavomycin and 3-Nitro-10. POULTRY SCIENCE 55: 1112-1116, 1976
INTRODUCTION
T
HIS study was the second of a series in which graded levels of an arsenical, 3-Nitro-10, and an antibiotic, Flavomycin, 3 were evaluated for their effects on broiler shank pigmentation when used with different coccidiostats. Pertinent literature was reviewed in the first paper (fry et al., 1976). In the study reported herein, Clopidol 4 was the coccidiostat used. MATERIALS AND METHODS Broilers were grown in five separate loca-
1. Florida Agr. Exp. Stas. Journal Series No. 6077. 2. Currently Assistant Dean for Resident Instruction, College of Agriculture, University of Florida, Gainesville, FL 32611. 3. Registered TM of Hoechst AG; also referred to as Moenomycin and Bambermycins. 4. Coyden25, The Dow Chen.ical Co., Midland, Mich. 48641.
tions in the facilities of the Poultry Science Department of the Agricultural Experiment Station of Florida (Exp. 1), Colorado (Exp. 2), Virginia (Exp. 3), Mississippi (Exp. 4), and Alabama (Exp. 5). Production data for these experiments were presented in the paper by Kling et al. (1976). Cobb x Cobb, Indian River cross, Cobb color sex, Cobb x Cobb, and Cobb color sex chicks were used at the five locations, respectively. Commercial-type broiler diets commonly used in each of the experimental locations were utilized in this study; no effort was made to standardize the xanthophyll levels in the different diets. All diets contained 0.0125% Clopidol. A 4 x 4 factorial arrangement of treatments was utilized with Flavomycin at levels of 0, 1,2 and 4 mg./kg. and 3-Nitro-10 at levels of 0, 25.0, 37.5 and 50.0 mg./kg. Shank pigmentation sampling and analyses were as described by Fry et al. (1976) except as follows. Twelve males and twelve females
1112
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 29, 2015
(Received for publication September 29, 1975)
BROILER PIGMENTATION
were selected from each treatment, from either three or four pen replications, at each location. The selections were random except that if a bird with dark or green shanks was caught, it was released and a replacement selected. This procedure was utilized due to the problems resulting in the evaluation of pigmentation of dark or green shanks (Fry and Harms, 1973).
^ « § S ji .a 2 2 % f>
c
c
'3
:-.
The data for DWL and EP are reported by Flavomycin and 3-Nitro-10 levels for Exp. 1, Exp. 2, Exp. 3, Exp. 4 and Exp. 5 in Tables 1, 2, 3, 4 and 5, respectively. The luminosity values tended to be negatively correlated with DWL and EP but, because
| 5 ^, .a J> "§ •a
of greater bird-to-bird variation than noted
g
in the other two parameters, was generally not significantly affected by either Flavomycin or 3-Nitro-10 in the diet. The females had lower luminosity and DWL values than the males in all five experiments; this was due no doubt to the tendency for females to have a higher incidence of dark or green shanks and occurred in spite of the efforts not to select such birds for evaluation. EP values were significantly higher for females in two experiments and significantly lower for females in one experiment. The only significant interaction noted in the entire study was a sex x Flavomycin interaction (P < 0.01) for DWL in Exp. 5. In Exp. 1 (Florida), 3-Nitro-10 significantly affected both DWL and EP of broiler shanks (Table 1). The 50.0 mg./kg. level produced the highest hue (DWL); however, the DWL of shanks of birds receiving no 3-Nitro-10 did not differ significantly from that of shanks of birds receiving any of the supplemental levels of this additive. The EP of the shanks of birds receiving no 3-Nitro-10 was significantly lower than those of birds receiving any of the three levels of this additive. Dietary Flavomycin did not affect shank DWL but
•g'? g '§ ^^ -o -< ° «• cy^ £>s §£ § a « -g ^ ^ & "§, -X « | | ^ J i —
00
H<
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 29, 2015
RESULTS AND DISCUSSION
Av. 578.34 578.07 578.23 578.24 578.22 0 58.05 59.06 61.88 61.78 60.20
Flav 1 59. 60.7 60. 58. 59.
DWL (nm.) Flavomycin (mg./kg.) 3-Nitro-10 4 1 2 (mg./kg.) 0 00.0 579.27 579.31 579.02 578.92 25.0 579.12 579.12 579.29 579.67 37.5 579.27 579.46 578.96 579.00 50.0 579.30 578.91 579.17 579.07 Av. 579.24 579.21 579.11 579.16 'Flavomycin means without common letters are significantly different
Flavo 0 1 579.13 62.26 62.6 579.30 60.45 64.2 579.17 62.08 64.5 579.11 61.61 62.0 579.18 61.60a 63.3 (P < 0.05). No differences due Av.
TABLE 3.—Shank dominant wavelength (DWL) and excitation purity (EP) of broilers fed graded levels of Clopidol (Exp. 3—Virginia)
3-Nitro-10 4 (mg. /kg.) 0 1 2 00.0 578.43 578.60 578.08 578.24 25.0 578.15 578.21 577.91 578.00 37.5 578.10 578.41 578.23 578.17 50.0 578.24 578.31 578.43 578.00 Av. 578.23 578.38 578.16 578.10 ' N o significant differences due to Flavomycin or 3-Nitro-10.
DWL(nm.)' Flavomycin (mg. /kg.)
TABLE 2.—Shank dominant wavelength (DWL) and excitation purity (EP) of broilers fed graded levels of Clopidol (Exp. 2—Colorado)
rom http://ps.oxfordjournals.org/ at North Dakota State University on May 29, 2015
0 52.70 53.18 56.93 54.50 54.34c 53.3 53.9 57.7 56.1 55.3
Flav 1
1
578.50 578.25 578.07 578.73 578.39cd
0
578.29 578.25 578.21 578.59 578.33c
578.56 578.58 578.52 578.33 578.50cd
578.25 578.58 578.43 578.98 578.56d
Av.
578.40a 578.42a 578.31a 578.66b 578.45 'Flavomycin means without common letters are significantly different (P < 0.05). 2 3-Nitro-10 means without common letters are significantly different (P < 0.05).
3-Nitro-10 (mg./kg.) 00.0 25.0 37.5 50.0 Av.
D W L ' 2 (nm.) Flavomycin (mg./kg.)
0 61.36 61.13 62.56 60.88 61.49
62 63 61 65 63
1
Flav
TABLE 5.—Shank dominant wavelength (DWL) and excitation purity (EP) of broilers fed graded levels o Clopidol (Exp. 5—Alabama)
0 4 Av. 578.41 578.22 00.0 578.26 578.98 25.0 578.57 578.47 578.24 37.5 578.41 577.91 578.32 50.0 578.42 578.43 578.44 Av. 578.39 578.33 'Flavomycin means without common letters are significantly different (P < 0.05). 2 3-Nitro-10 means without common letters are significantly different (P < 0.05).
3-Nitro-10 (mg./kg.)
DWL (nm.) Flavomycin (mg./kg.) 1 2 577.88 578.54 577.70 578.61 578.71 578.77 578.68 578.23 578.24 578.54
TABLE 4.—Shank dominant wavelength (DWL) and excitation purity (EP) of broilers fed graded levels of Clopidol (Exp. 4—Mississippi)
from http://ps.oxfordjournals.org/ at North Dakota State University on May 29, 2015
1116
J. L. FRY, R. H. HARMS, M. W. MOELLER AND H. F. KLING
In the birds grown in Alabama, both Flavomycin and 3-Nitro-10 resulted in significant increases in body weight (Kling et al., 1976). Likewise both of these additives produced significant increases in shank DWL (Table
5). The DWL values for the birds receiving 50.0 mg./kg. 3-Nitro-10 were significantly higher than those of the 0.0, 25.0 and 37.5 mg./kg. levels. Flavomycin at 4 mg./kg. produced DWL responses significantly higher than in birds receiving no Flavomycin. The responses to the two additives on EP approached significance at the P < .05 level. The addition of Flavomycin to the diet of broilers resulted in significantly increasing EP of shanks in three of five experiments. The addition of 3-Nitro-10 to the diet resulted in significantly increasing EP of shanks in two experiments and a numerical increase in the third. No explanation can be given for the lack of response to the additives at certain locations. These increases in shank EP would be of commercial importance since an increase of 1.0% in excitation purity is equivalent to an increase of slightly more than 1 gram of xanthophyl per ton of feed. This relationship is based upon the observations of Herrick et al. (1972) who reported that one gram of Beta-apo-8' carotenoic acid ethyl ester resulted in a 1.0% improvement in shank excitation purity.
REFERENCES Fry, J. L., and R. H. Harms, 1973. Relationship of yellow and "green" or dark shanks to skin color and pigmentation evaluation of broilers. Poultry Sci. 52: 1986-1988. Fry, J. L., R. H. Harms and M. W. Moeller, 1976. Effect of Flavomycin and 3-Nitro-10 on broiler pigmentation when used with different coccidiostats. 1. Amprol Hi-E. Poultry Sci. 55: 744-748. Herrick, G. M., J. L. Fry and R. H. Harms, 1972. The use of Beta-Apo-8-carotenoic acid ethyl ester as a standard for determination of xanthophyll utilization from natural sources by broilers. Poultry Sci. 51:428-435. Kling, H. F., M. W. Moeller, B. L. Damron, R. H. Harms, C. L. Quarles, L. M. Potter, W. L. Beane, B. C. Dilworth, E. J. Day and S. A. Edgar, 1976. Response to Flavomycin and 3-Nitro in broiler chicken diets containing Clopidol. Poultry Sci. 55: 694-699.
Downloaded from http://ps.oxfordjournals.org/ at North Dakota State University on May 29, 2015
the addition of Flavomycin at any of the three levels produced shank EP (intensity) significantly higher than that of the birds receiving no Flavomycin. In the evaluation of the production responses (Kling et al., 1976), Flavomycin and 3-Nitro-10 both significantly increased broiler body weights. Flavomycin produced significant improvements in both body weight and feed efficiency of the broilers grown at the Colorado Experiment Station (Kling et al., 1976). Yet in the evaluation of the pigmentation of these birds (Table 2) neither Flavomycin nor 3-Nitro-10 resulted in significant effects on shank DWL and EP although the increases attributable to 3-Nitro-10 approached significance. In Exp. 3 (Virginia), Flavomycin significantly affected EP values (Table 3). The shanks of birds receiving no Flavomycin were significantly less pigmented than those of birds receiving any of the three levels of Flavomycin. The shanks of birds receiving 2 mg./kg. of Flavomycin did not differ significantly from those receiving 1 or 4 mg. /kg. but the latter two levels produced significantly different EP values. Flavomycin also significantly improved feed efficiency of these broilers (Kling et al., 1976). Although both Flavomycin and 3-Nitro-10 produced significant shank EP responses in the birds grown in Mississippi (Table 4), the only significant production response was that of 3-Nitro-10 on body weight (Kling et al., 1976). The highest shank EP value produced by 3-Nitro-10 was that of the 37.5 mg./kg. level. This level did not differ significantly from that of the 50.0 mg./kg. level but was significantly higher than the 0.0 and 25.0 mg./kg. levels. The highest level of Flavomycin produced the highest average shank EP.