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Bacterial Flora of Poultry Kidneys and Effects of Kidney Removal on Yield and Shelf-Life
56
E. W. HENDERSON
Neither the Jungle Fowl males nor females were pedigreed. They were "pure," phenotypically, and believed to be descendants of Wild Jungle Fowl imported from India. The pens of females were identical in both the cross and the pure matings. SUMMARY
REFERENCES Hutt, F. B., 1949. Genetics of the Fowl. 590 pp. McGraw-Hill, New York. Henderson, E. W., 1952. A silver laced chicken with Cornish ancestry. Michigan Agr. Expt. Sta. Quart. Bui. 35 (1): 125-129.
Bacterial Flora of Poultry Kidneys and Effects of Kidney Removal on Yield and Shelf-Life E. O. ESSARY* AND C. E. HOWES Virginia Agricultural Experiment Station, Blacksburg (Received for publication May 19, 1959)
T
HE Poultry Products Inspection Act, Public Law 85-172, as originally proposed, would have required that all kidneys be removed from inspected ready-to-cook poultry. Following wide-spread objections this provision was modified before being written into the final regulations. However, there appears to be some doubt as to whether normal appearing kidneys in normal appearing poultry carcasses are likely to be wholesome for human consumption. A review of literature did not furnish information on factors associated with removing kidneys from poultry. Therefore, it seemed advisible to set up an experiment to evaluate some of the factors associated with kidney removal. * The helpful assistance of C. Y. Kramer, Dept. of Statistics, W. E. C. Moore, Dept. of Biochemistry and Microbiology, and V. F. Holt, Poultry Department is gratefuly acknowledged.
PROCEDURE
One hundred and five 8-week old White Rock broilers, two different groups of 10week old crossbred fryers (one group of 40 birds and another of 50) and 49 White Leghorn fowl were killed by a throat slash, scalded at 138°F. and picked on a small drum-type picker at the Virginia Agricultural Experiment Station to determine the difference in warm eviscerated yield of carcasses, with and without kidneys. Each eviscerated bird was first weighed with the kidneys in the carcass. The kidneys were then removed by using forceps and knife, and the birds weighed again. The eviscerated yields were then computed with and without kidneys. Another group of 80 10-week old White Rock fryers were used to determine the percent chill pick-up and shelf-life of birds with and without kidneys. The birds were
Downloaded from http://ps.oxfordjournals.org/ at Northern Arizona University on July 5, 2015
From shank colors of progenies of Silver Cornish and a strain of Wild Red Jungle Fowl mated inter se and reciprocally crossed, it was determined that the genotype of the blue shank color of a population of Wild Red Jungle Fowl is similar to that
of domestic fowl. The blue shank color of the Red Jungle Fowl appears to be sexlinked (id id) and autosomal (WW) for males and (id— WW) for females. There was some slight evidence of incomplete dominance of both genes. The genotype of the Silver Cornish appeared to be 100% (Id Id ww) in males and (Id— ww) in females.
57
EFFECT OF KIDNEYS ON SHELF-LIFE
Starting on the seventh day of storage, daily observations of the odor of each bird were made. All observations were conducted individually by two workers (the same throughout the test) in a room separate from the cooler. Each bird which had developed off-odor was placed aside until all birds had been checked for the day. Each bird was also examined to determine the anatomical area in which off-odors appeared. After these observations had been made the identities of the birds were checked. The average shelf-life in days for each group was determined for each treatment. Another group of 19 10-week old White Rock fryers was utilized to determine the degree of bacterial contamination of one kidney and a piece of liver from each carcass. Ten of these fryers were killed as described before. The other 9 birds were killed by dislocating the head and allowing the blood to accumulate in the neck skin. The latter procedure was used in order to eliminate the possibility of the killing knife placing microorganisms in the blood to be carried to various parts of the body. The birds were then scalded and picked as mentioned before. The exterior surface of the abdominal area of each fryer was disinfected using
70% ethyl alcohol. The abdominal cavity was opened with surgical scissors which had been held for several minutes in 70% ethyl alcohol. The right kidney and a piece of liver, to be used as control tissue, comparable in size to the kidney were removed from each carcass. Precautions were used to remove the tissues aseptically. The samples were placed in 100 ml. bottles of sterile buffer solution containing a quantity of ground glass. The bottles were shaken vigorously for several minutes in order to shred the tissue. One ml. of the inoculum was transferred to pour-plates of GTE agar. Total counts were made after the plates were incubated at room temperature for 48 hours. RESULTS AND DISCUSSION Warm eviscerated yields of one group of 8-week old broilers, two different groups of 10-week old broilers and the group of year old fowl, before and after kidney removal, are shown in Table 1. It may be noted that the average percent yield of 8-week old broilers was reduced from 67.45 to 66.63%, a difference of 0.82%. For the two different groups of 10-week old fryers, the average eviscerated yields were reduced from 71.50 to 70.80%, and from 69.80 to 69.07%, respectively, a loss of approximately 0.70% in each case. The average yield of fowl was reduced from 69.81 to 69.15%, a loss of 0.66%. These differences in yield were significant at the 1% level of probability (Tables 2 to 5, inclusive). The average percent weight increase after chilling 40 10-week old fryers in ice TABLE 1.—Average warm eviscerated yield of broilers, fryers, and fowl, before and after kidney removal N o . and class of poultry
Bird age in weeks
105 (broilers) 40 (fryers) 50 (fryers) 9 (fowl)
8 10 10 52 (approx.)
Average yield with kidneys 67.45 71.50 69.80 69.81
Average % l o s s yield from without kidney kidneys removal 66.63 70.80 69.07 69.15
0.82 0.70 0.73 0.66
Downloaded from http://ps.oxfordjournals.org/ at Northern Arizona University on July 5, 2015
divided at random into two groups of 40 birds each and processed as previously described. The kidneys were removed from one group of 40 birds in the same manner as earlier described. Each carcass was weighed to the nearest gram, chilled in ice slush for approximately 4 hours, allowed to drain for 10 minutes, and reweighed. The carcasses were then cut-up, packed in trays containing blotters, and overwrapped with MST 7-300 cellophane. Each tray was coded underneath to identify the treatment. The tray-pack fryers were placed on slatted shelves in a 38°F. cooler for the test.
58
E . 0 . ESSARY AND C. E . HOWES TABLE 2.—Analysis of variance of data for 8-week broilers, Table 1 Source of variation
d.f.
Mean square
With and without kidneys broilers Error '
1 104 104
34.5182** 5.0828** 0.0041
** P < . 0 1 .
TABLE 3.—Analysis of variance of data for 40 fryers, Table 1 d.f.
With and without kidneys fryers Error
1 39 39
Mean square 9.9475** 4.8581** 0.0020
**P<.01.
TABLE 4.—Analysis of variance of data for 50 fryers, Table 1 Source of variation
d.f.
Mean square
With and without kidneys fryers Error
1 49 49
13.1406** 5.4306** 0.0052
**P<.01.
TABLE 5.—Analysis of variance of data for 49 fowl, Table 1 Source of variation
d.f.
Mean square
With and without kidneys fowl Error
1 48 48
10.8845** 25.3304** 0.0112
**P<.01.
TABLE 6.—Percent weight increase from chilling fryers in ice slush, with and without kidneys
TABLE 7.—Analysis of variance of data, Table 6 U.VFU.,
No. fryers in each group 40
Average percent increase with kidneys
without kidneys
4.02
5.29
Average % weight increase
..
Source of variation
d.f.
Mean square
Between treatments within treatments Error
1 78 78
32.6785** 1.1291
1.27 **P<.01.
Downloaded from http://ps.oxfordjournals.org/ at Northern Arizona University on July 5, 2015
Source of variation
slush for approximately 4 hours was 4.02 % for those with kidneys and 5.29% for those with the kidneys removed (Table 6). Apparently the crypts occupied by the kidneys trapped small quantities of water. This difference in weight increase was significant at the 1% level of probability, Table 7. The fryers used to determine the weight increase from chilling were also used to study the influence of kidney removal on the average shelf-life of cut-up fryers held in a 38°F. cooler. The average shelf-life was 12.63 days for those with kidneys and 13.26 days for those with the kidneys removed. This difference was significant at the 5% level of probability. It was observed that off-odors were more prevalent on the skin, particularly in the area of the crop. The number of bacterial colonies on the plates containing inoculum of kidney and liver tissue is shown in Table 8. It may be noted that 42.1% of the plates with inoculum from kidneys and 84.2% of those with liver tissue showed no bacterial growth. This difference could be attributable to the fact that the liver was removed from the carcass first each time which would allow more exposure time for contamination of the kidney. One of the liver plates and three of the kidney plates which exhibited growth showed only one colony each. The colony appeared to be Bacillus mycoides. The other colonies were small, circular, and white in appearance. The organisms were not isolated and characterized. While it was not established that these colonies were
59
EFFECT OF KIDNEYS ON SHELF-LIFE TABLE 8.—Plate counts of inoculum from kidneys and livers Kidney
Liver
No. colonies per plate
No. plates
0 1 2 4 5 Discarded lab errors
8 6 1 1 1 2
% of total plates
No. colonies per plate
42 31 •S 5 5 10
No. plates
% of total plates
16 2 1
84.2 10.S 5.2
average weight increase from chilling 10week old fryers in ice slush for 4 hours was 4.02% for those with kidneys and 5.29% for those without kidneys which difference was significant at the 1% level of probability. Shelf-life was extended on the average SUMMARY by 1.27 days with fryers which had the Tests were conducted to determine the kidneys removed. Approximately 42% of the plates with average loss in warm eviscerated yields of 8-week old broilers, 10-week old fryers, and inoculum from kidneys and 84% of those one-year old S. C. White Leghorn fowl be- from livers showed no colonies. Part of the fore and after kidney removal. The percent plates with growth had only one colony, loss in yield from kidney removal was which appeared to be Bacillus mycoides. 0.82% for the 8-week old broilers, approxi- The largest number of bacterial colonies in mately 0.70% for each group of 10-week any of the plates did not exceed 5. Other old fryers, and 0.66% for the S. C. White tests need to be conducted under plant conLeghorn fowl. These differences were sig- ditions to further evaluate kidney removal nificant at the 1 % level of probability. The from poultry carcasses.
Vitamin E Activity of Selenium in Turkey Hatchability C. R. CEEGER, R. H. MITCHELL, R. L. ATKINSON, T. M FERGUSON, Departments
B. L. REID AND J. R. COUCH of Biochemistry and Nutrition and Poultry Science, Texas A & M College, College Station, Texas (Received for publication May 19, 1959)
INTRODUCTION
NUMBER of workers have reported the vitamin E-like activity of selenium in preventing exudative diathesis in chicks (Schwartz et al., 1957; Reid et al., 1958; and Patterson et al., 1957). Schwartz
A
et al. (1957) reported dried brewers yeast and vitamin-free casein completely prevented symptoms of exudative diathesis and promoted good growth when fed at the 10% level in the diet of rats. They also reported the presence of a factor 3, which
Downloaded from http://ps.oxfordjournals.org/ at Northern Arizona University on July 5, 2015
the results of contamination, it seems logical to assume that bacterially infected tissue would give more colonies per plate than the number observed. Of course, viruses could have been present in the agar without being noticeable.
E. W. HENDERSON
Neither the Jungle Fowl males nor females were pedigreed. They were "pure," phenotypically, and believed to be descendants of Wild Jungle Fowl imported from India. The pens of females were identical in both the cross and the pure matings. SUMMARY
REFERENCES Hutt, F. B., 1949. Genetics of the Fowl. 590 pp. McGraw-Hill, New York. Henderson, E. W., 1952. A silver laced chicken with Cornish ancestry. Michigan Agr. Expt. Sta. Quart. Bui. 35 (1): 125-129.
Bacterial Flora of Poultry Kidneys and Effects of Kidney Removal on Yield and Shelf-Life E. O. ESSARY* AND C. E. HOWES Virginia Agricultural Experiment Station, Blacksburg (Received for publication May 19, 1959)
T
HE Poultry Products Inspection Act, Public Law 85-172, as originally proposed, would have required that all kidneys be removed from inspected ready-to-cook poultry. Following wide-spread objections this provision was modified before being written into the final regulations. However, there appears to be some doubt as to whether normal appearing kidneys in normal appearing poultry carcasses are likely to be wholesome for human consumption. A review of literature did not furnish information on factors associated with removing kidneys from poultry. Therefore, it seemed advisible to set up an experiment to evaluate some of the factors associated with kidney removal. * The helpful assistance of C. Y. Kramer, Dept. of Statistics, W. E. C. Moore, Dept. of Biochemistry and Microbiology, and V. F. Holt, Poultry Department is gratefuly acknowledged.
PROCEDURE
One hundred and five 8-week old White Rock broilers, two different groups of 10week old crossbred fryers (one group of 40 birds and another of 50) and 49 White Leghorn fowl were killed by a throat slash, scalded at 138°F. and picked on a small drum-type picker at the Virginia Agricultural Experiment Station to determine the difference in warm eviscerated yield of carcasses, with and without kidneys. Each eviscerated bird was first weighed with the kidneys in the carcass. The kidneys were then removed by using forceps and knife, and the birds weighed again. The eviscerated yields were then computed with and without kidneys. Another group of 80 10-week old White Rock fryers were used to determine the percent chill pick-up and shelf-life of birds with and without kidneys. The birds were
Downloaded from http://ps.oxfordjournals.org/ at Northern Arizona University on July 5, 2015
From shank colors of progenies of Silver Cornish and a strain of Wild Red Jungle Fowl mated inter se and reciprocally crossed, it was determined that the genotype of the blue shank color of a population of Wild Red Jungle Fowl is similar to that
of domestic fowl. The blue shank color of the Red Jungle Fowl appears to be sexlinked (id id) and autosomal (WW) for males and (id— WW) for females. There was some slight evidence of incomplete dominance of both genes. The genotype of the Silver Cornish appeared to be 100% (Id Id ww) in males and (Id— ww) in females.
57
EFFECT OF KIDNEYS ON SHELF-LIFE
Starting on the seventh day of storage, daily observations of the odor of each bird were made. All observations were conducted individually by two workers (the same throughout the test) in a room separate from the cooler. Each bird which had developed off-odor was placed aside until all birds had been checked for the day. Each bird was also examined to determine the anatomical area in which off-odors appeared. After these observations had been made the identities of the birds were checked. The average shelf-life in days for each group was determined for each treatment. Another group of 19 10-week old White Rock fryers was utilized to determine the degree of bacterial contamination of one kidney and a piece of liver from each carcass. Ten of these fryers were killed as described before. The other 9 birds were killed by dislocating the head and allowing the blood to accumulate in the neck skin. The latter procedure was used in order to eliminate the possibility of the killing knife placing microorganisms in the blood to be carried to various parts of the body. The birds were then scalded and picked as mentioned before. The exterior surface of the abdominal area of each fryer was disinfected using
70% ethyl alcohol. The abdominal cavity was opened with surgical scissors which had been held for several minutes in 70% ethyl alcohol. The right kidney and a piece of liver, to be used as control tissue, comparable in size to the kidney were removed from each carcass. Precautions were used to remove the tissues aseptically. The samples were placed in 100 ml. bottles of sterile buffer solution containing a quantity of ground glass. The bottles were shaken vigorously for several minutes in order to shred the tissue. One ml. of the inoculum was transferred to pour-plates of GTE agar. Total counts were made after the plates were incubated at room temperature for 48 hours. RESULTS AND DISCUSSION Warm eviscerated yields of one group of 8-week old broilers, two different groups of 10-week old broilers and the group of year old fowl, before and after kidney removal, are shown in Table 1. It may be noted that the average percent yield of 8-week old broilers was reduced from 67.45 to 66.63%, a difference of 0.82%. For the two different groups of 10-week old fryers, the average eviscerated yields were reduced from 71.50 to 70.80%, and from 69.80 to 69.07%, respectively, a loss of approximately 0.70% in each case. The average yield of fowl was reduced from 69.81 to 69.15%, a loss of 0.66%. These differences in yield were significant at the 1% level of probability (Tables 2 to 5, inclusive). The average percent weight increase after chilling 40 10-week old fryers in ice TABLE 1.—Average warm eviscerated yield of broilers, fryers, and fowl, before and after kidney removal N o . and class of poultry
Bird age in weeks
105 (broilers) 40 (fryers) 50 (fryers) 9 (fowl)
8 10 10 52 (approx.)
Average yield with kidneys 67.45 71.50 69.80 69.81
Average % l o s s yield from without kidney kidneys removal 66.63 70.80 69.07 69.15
0.82 0.70 0.73 0.66
Downloaded from http://ps.oxfordjournals.org/ at Northern Arizona University on July 5, 2015
divided at random into two groups of 40 birds each and processed as previously described. The kidneys were removed from one group of 40 birds in the same manner as earlier described. Each carcass was weighed to the nearest gram, chilled in ice slush for approximately 4 hours, allowed to drain for 10 minutes, and reweighed. The carcasses were then cut-up, packed in trays containing blotters, and overwrapped with MST 7-300 cellophane. Each tray was coded underneath to identify the treatment. The tray-pack fryers were placed on slatted shelves in a 38°F. cooler for the test.
58
E . 0 . ESSARY AND C. E . HOWES TABLE 2.—Analysis of variance of data for 8-week broilers, Table 1 Source of variation
d.f.
Mean square
With and without kidneys broilers Error '
1 104 104
34.5182** 5.0828** 0.0041
** P < . 0 1 .
TABLE 3.—Analysis of variance of data for 40 fryers, Table 1 d.f.
With and without kidneys fryers Error
1 39 39
Mean square 9.9475** 4.8581** 0.0020
**P<.01.
TABLE 4.—Analysis of variance of data for 50 fryers, Table 1 Source of variation
d.f.
Mean square
With and without kidneys fryers Error
1 49 49
13.1406** 5.4306** 0.0052
**P<.01.
TABLE 5.—Analysis of variance of data for 49 fowl, Table 1 Source of variation
d.f.
Mean square
With and without kidneys fowl Error
1 48 48
10.8845** 25.3304** 0.0112
**P<.01.
TABLE 6.—Percent weight increase from chilling fryers in ice slush, with and without kidneys
TABLE 7.—Analysis of variance of data, Table 6 U.VFU.,
No. fryers in each group 40
Average percent increase with kidneys
without kidneys
4.02
5.29
Average % weight increase
..
Source of variation
d.f.
Mean square
Between treatments within treatments Error
1 78 78
32.6785** 1.1291
1.27 **P<.01.
Downloaded from http://ps.oxfordjournals.org/ at Northern Arizona University on July 5, 2015
Source of variation
slush for approximately 4 hours was 4.02 % for those with kidneys and 5.29% for those with the kidneys removed (Table 6). Apparently the crypts occupied by the kidneys trapped small quantities of water. This difference in weight increase was significant at the 1% level of probability, Table 7. The fryers used to determine the weight increase from chilling were also used to study the influence of kidney removal on the average shelf-life of cut-up fryers held in a 38°F. cooler. The average shelf-life was 12.63 days for those with kidneys and 13.26 days for those with the kidneys removed. This difference was significant at the 5% level of probability. It was observed that off-odors were more prevalent on the skin, particularly in the area of the crop. The number of bacterial colonies on the plates containing inoculum of kidney and liver tissue is shown in Table 8. It may be noted that 42.1% of the plates with inoculum from kidneys and 84.2% of those with liver tissue showed no bacterial growth. This difference could be attributable to the fact that the liver was removed from the carcass first each time which would allow more exposure time for contamination of the kidney. One of the liver plates and three of the kidney plates which exhibited growth showed only one colony each. The colony appeared to be Bacillus mycoides. The other colonies were small, circular, and white in appearance. The organisms were not isolated and characterized. While it was not established that these colonies were
59
EFFECT OF KIDNEYS ON SHELF-LIFE TABLE 8.—Plate counts of inoculum from kidneys and livers Kidney
Liver
No. colonies per plate
No. plates
0 1 2 4 5 Discarded lab errors
8 6 1 1 1 2
% of total plates
No. colonies per plate
42 31 •S 5 5 10
No. plates
% of total plates
16 2 1
84.2 10.S 5.2
average weight increase from chilling 10week old fryers in ice slush for 4 hours was 4.02% for those with kidneys and 5.29% for those without kidneys which difference was significant at the 1% level of probability. Shelf-life was extended on the average SUMMARY by 1.27 days with fryers which had the Tests were conducted to determine the kidneys removed. Approximately 42% of the plates with average loss in warm eviscerated yields of 8-week old broilers, 10-week old fryers, and inoculum from kidneys and 84% of those one-year old S. C. White Leghorn fowl be- from livers showed no colonies. Part of the fore and after kidney removal. The percent plates with growth had only one colony, loss in yield from kidney removal was which appeared to be Bacillus mycoides. 0.82% for the 8-week old broilers, approxi- The largest number of bacterial colonies in mately 0.70% for each group of 10-week any of the plates did not exceed 5. Other old fryers, and 0.66% for the S. C. White tests need to be conducted under plant conLeghorn fowl. These differences were sig- ditions to further evaluate kidney removal nificant at the 1 % level of probability. The from poultry carcasses.
Vitamin E Activity of Selenium in Turkey Hatchability C. R. CEEGER, R. H. MITCHELL, R. L. ATKINSON, T. M FERGUSON, Departments
B. L. REID AND J. R. COUCH of Biochemistry and Nutrition and Poultry Science, Texas A & M College, College Station, Texas (Received for publication May 19, 1959)
INTRODUCTION
NUMBER of workers have reported the vitamin E-like activity of selenium in preventing exudative diathesis in chicks (Schwartz et al., 1957; Reid et al., 1958; and Patterson et al., 1957). Schwartz
A
et al. (1957) reported dried brewers yeast and vitamin-free casein completely prevented symptoms of exudative diathesis and promoted good growth when fed at the 10% level in the diet of rats. They also reported the presence of a factor 3, which
Downloaded from http://ps.oxfordjournals.org/ at Northern Arizona University on July 5, 2015
the results of contamination, it seems logical to assume that bacterially infected tissue would give more colonies per plate than the number observed. Of course, viruses could have been present in the agar without being noticeable.