- Email: [email protected]
Studies in Hatchery Sanitation
114
R. A. CHUNG, E. Y. DAVIS, R. A. MUNDAY AND J. M. J. NING Fatty acid composition of cardiac lipids as affected by dietary cholesterol. Boll. Soc. Ital. Biol. Sper. 38: 1517-1519. Sykes, J. F., J. A. Davidson and F. N. Barrett, 1945. The effect of feeding diethylstilbestrol to cockerels. Poultry Sci. 24: 542-545. Stoffel, W., F. Chu and E. H. Ahrens, Jr., 1959. Analysis of long-chain fatty acids by gas-liquid chromatography. Anal. Chem. 3 1 : 307-308. Taurog, A., F. W. Lorenz, C. Entenman and I. L. Chaikoff, 1944. The effect of diethylstilbestrol on the vitor formation of phospholipids in the liver as measured with radioactive phosphorus. Endocrinology, 35: 483-487. Umberger, E. J., G. H. Goss, K. J. Davis, J. M. Curtis and C. G. Durbin, 1959. Estrogenic residues in the edible tissues of stilbestrol-fattened chickens. Poultry Sci. 38: 118-128. Witten, P. W., and R. T. Holman, 1942. Polyethenoid fatty acid metabolism. VI. Effect of pyridoxine on essential fatty acid conversions. Arch. Biochem. Biophys. 4 1 : 266-273.
Studies in Hatchery Sanitation 4. EFFECT OF REGULAR FLOOR DISINFECTION ON BACTERIAL POPULATIONS IN HATCHERS AND THROUGHOUT THE HATCHERY ENVIRONMENT UNDER COMMERCIAL CONDITIONS S. E. MAGWOOD1 Canada Department of Agriculture, Hull, Quebec (Received for publication June 4, 1966)
I
N OUR previous studies of the bacterial ecology of commercial hatcheries (Magwood, 1964b; and Magwood and Marr, 1964) it was found that the size of the bacterial populations in the hatching machines was directly related to the number of air-borne bacteria in the hatchery. These organisms, which fell on horizontal surfaces such as floors and tables, constituted a reservoir from which they could be made air-borne by employee activity, and, 1 Animal Pathology Division, Health of Animals Branch, Canada Department of Agriculture, Animal Diseases Research Institute, Hull, Quebec.
when drawn into the hatching machines they contaminated successive hatches. The bacteria multiplied rapidly in the nutritious fluids surrounding the emerging chicks. As the chicks dried off, the dust and fluff particles from the young birds, with adherent organisms, were expelled from the hatchers to spread throughout the hatchery rooms. In experimental studies the role of airborne bacteria in the contamination of hatching birds by these organisms was clearly demonstrated by Magwood (1964b). The shell surface of eggs incubated in a heavily contaminated non-commercial
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 15, 2015
- C " by the laying hen. J. Nutrition, 72: 451454. Privett, O. S., M. L. Bland and J. A. Schmit, 1962. Studies on the composition of egg lipid. J. Food Sci. 27: 463-468. Ranney, R. E., and I. L. Chaikoff, 1951. Effect of functional hepatectomy upon estrogen-induced lipemia in the fowl. Am. J. Physiol. 165: 600603. Reinis, A., V. Puchmayer, M. Sulc and A. Duben, 1962. Effect of estrogen treatment on the lipid metabolism of fowl. Sb. Lekar, 64: 340-346. Riddle, O., and D. F. Opdyke, 1941. Hormones capable of increasing liver fat. Science, 9 3 : 440. Reiser, R., 1950. The metabolism of polyunsaturated fatty acids in growing chicks. J. Nutrition, 42: 325-336. Rieckenhoff, I. G., R. T. Holman and G. O. Burr, 1949. Polyethenoid fatty acid metabolism. Effect of dietary polyethenoid fatty acids of rat tissues. Arch. Biochem. 20: 331-340. Rossi, S., M. Martinelli and E. Turchetto, 1962.
HATCHERY SANITATION
The obvious practical application of these findings to hatcheries where sanitary conditions are sub-optimal is to attempt to minimize bacterial contamination in the hatchery environment. Three commercial hatcheries whose sanitary status was known, as judged by the routine microbiological test of hatcher fluff samples, agreed to co-operate in a trial under field conditions. The sanitary status of the three plants, based on previous fluff tests, was as follows: S-good, P-fair, SP-unsatisfactory. MATERIALS AND METHODS
The hatcheries were registered commercial operations whose individual annual production lay between two and four million chicks. In two of the plants, (S and P), four rooms were given experimental treatment; two of these were devoted to sorting, sexing and shipping, the other two were the setter and hatcher rooms. In the third plant (SP) the chick processing area was treated as one room. Each hatchery had more than one kind of floor surface, S had terrazzo and concrete; P had concrete, painted concrete and vinyl asbestos; SP had a wooden floor in the setter room and concrete floors in the others. Seven separate examinations were made
at the S and SP plants and the P hatchery was tested ten times. The initial examinations were made during a hatching period before the disinfectant washing procedure was introduced. At hatchery SP the floor washing was discontinued after the fourth examination and was resumed three months later, before the sixth examination. Following the regular "clean-up" after each hatch the room floors were washed with a detergent-sanitizer* solution, mixed according to the manufacturer's directions, and applied with a mop. The tables and counters were wiped with a similar solution. In addition, other sources which could contribute to air-borne contamination, when located, were eliminated. One of these was the practice at one of the hatcheries of changing soiled chick box pads in the sorting room. Bacteriological populations of the air and of the floors in the rooms were determined during the removal and processing of hatches when the level of contamination was likely to be highest. For determining the counts of air-borne bacteria or "air counts," a TDL slit sampler was employed as described by Magwood (1964a). The values reported the plate counts of colonies per cubic foot of air. For the bacterial populations on the floors the mean counts were estimated by the bacteriological-graphical method described by Magwood and Marr (1964). In this method the "soil" from 0.06 square inch of a floor surface is transferred on a swab to a quadrant of a trypticase glucose extract agar plate (Baltimore Biological Laboratories). This is repeated a total of 8 or 12 times in order to sample many areas of the surface. The mean counts and 95 percent confidence limits are determined by the use of specially designed nomograms. * Breakthrough—Proctor & Gamble, Toronto, Ontario.
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 15, 2015
hatchery picked up large numbers of bacteria from the air circulating through the incubator. During hatching in this same environment, the bacterial populations on the shells, in the air and on various surfaces rose to very high levels. In contrast, when the eggs were transferred after 18 days of incubation to hatch in an uncontaminated environment, the bacteria on the shells died off to almost zero. During and after hatching in this clean environment, practically no bacteria could be recovered from the eggs, the body surfaces of the chicks, the surfaces of the hatcher or the air in the room.
115
116
S. E. MAGWOOD
RESULTS AND DISCUSSION The results at the three plants are charted in Figures 1-3. The values for the room floors have been plotted vertically on a logarithmic scale for each examination. The curve is an approximation of the median of these values for the several examinations. The setter room and the hatcher room floors always had the lowest and highest values, respectively; the counts for the chick processing rooms lay between these extremes. The air counts ranked in the
HATCHERY 'SP'
BACTERIAL COUNTS PER CUBIC FOOT OF AIR , -BACTERIAL COUNTS PER 0.06 SQUARE INCH OF FLOOR
HATCHERY 'S' I AND I AND
BACTERIAL COUNTS PER CUBIC FOOT OF AIR BACTERIAL COUNTS PER 0.06 SQUARE INCH OF FLOOR
FLOOR DISINFECTION SUSPENDED APPROX. 2 MONTHS DISINFECTION RESUMED
0
1
_l_ 1.5
2
3
_l_ 7
MONTHS AFTER START OF INTERMITTENT FLOOR DISINFECTION
FIGS. 1-3. The effect of regular floor disinfection on the bacterial populations of the air and of the floor in three commercial hatcheries. At hatchery P on the nine-month test a marked rise in the counts occurred during dust-producing renovations. Their previous sanitary status, as judged by routine tests of hatchery fluff, was as follows: Sgood, P-fair, SP-unsatisfactory.
a
1 1.5 2 3 MONTHS AFTER START OF REGULAR FLOOR DISINFECTION
7
HATCHERY 'P' & AND h AND
BACTERIAL COUNTS PER CUBIC FOOT OF AIR BACTERIAL COUNTS PER 0.06 SQUARE INCH OF FLOOR 1600-4000
8 20 z S 10
0 2 3 3.5 4 5 9 10 20 21 MONTHS AFTER START OF REGULAR FLOOR DISINFECTION
same order as the floor counts for the rooms and have been plotted in a similar fashion. Due to a technical difficulty it was not possible to utilize the floor counts of the second and third examinations at S and SP and of the third and fourth examinations at P. It seems plausible that the close relationship between air and floor counts would have existed at these examinations also. The initial values at hatchery S were low, possibly due, in part at least, to good design, dense floor surfaces and good housekeeping practices including the use of a floor disinfectant. The values were carried to even lower levels during the trial period. At hatchery P the initial values were
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 15, 2015
OAND
117
HATCHERY SANITATION
At hatchery SP the introduction of floor washing was followed by a marked decline in the air and the floor counts. When this procedure was suspended the counts rose to nearly their former levels, but after resumption of floor washing, they fell to moderate values. Observations reported in Parts 2 and 3 of this series (Magwood and Marr, 1964; and Magwood 1964b) have shown that, in commercial hatcheries, bacterial populations on surfaces inside the hatchers, including the trays, were of moderate size at the end of hatching, even in those plants judged to be less sanitary than desirable. The cleaning and washing of the hatchers reduced this contamination to a lower level. Despite the relatively satisfactory sanitary state of the machines in those plants which had high air and floor counts, successive lots of chicks hatched in these previously clean machines, had very high bacterial counts on the fluff and dust which arose. In contrast, in those plants which had regularly reduced environmental contamination by a "through-the-plant clean-up" chicks were consistently hatched without this marked bacterial multiplication. All of the evidence indicates that sanitizing hatching machines
alone is not sufficient. Reducing the viable microorganisms to low numbers throughout the hatchery premises, as well as in the machines, is the main objective of what can be called hatchery environmental contamination control. When the same problem of air-borne contaminants was encountered in critical assembly areas of space-vehicle components, "clean-room" techniques were developed which included highly efficient filtration of the air and precise control of its flow. These techniques were found to be applicable to contamination control in hospital operating rooms and under simulated operating room conditions Beck and Frey (1966) considered that the method fulfilled the requirements for air asepsis. Although these methods may not be economically feasible for the hatchery industry, the principles and techniques employed in maintaining industrial "clean areas" would greatly aid in designing hatcheries that can more easily be kept biologically clean. SUMMARY Previous experimental studies had shown that air-borne bacteria contaminated chicks during hatching. The reservoir of this contamination was believed to be dust accumulations on the hatchery floor and other horizontal surfaces. Therefore a program of regular floor disinfection was conducted in three commercial hatcheries, and the effect of this measure on bacterial populations of the air and floor surfaces determined at intervals for many months. After the introduction of this program a marked reduction was observed in the size of these populations during the processing of hatches, the time when they are likely to be highest. The results support the conclusion that bacteria in the environment, which on becoming air-borne, contaminate hatching chicks, can be minimized by regularly reducing the counts on horizontal surfaces.
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 15, 2015
much higher than at S, they fell considerably in the early part of the trial, then rose abruptly at the fifth examination. During this fifth test extensive renovations were in progress which may have accounted for the rise. At subsequent tests the values were much reduced but not to the low levels achieved by S. The air exhausted by fans from a building which housed large numbers of growing birds close by the P hatchery may have contributed to their higher counts, particularly during conditions of atmospheric inversion when there is no natural movement of the outside air. In this atmospheric state the counts of air outside hatchery P were found to exceed 200 in one instance (Magwood, 1964a).
118
S. E. MAGWOOD
It should be possible to employ techniques and principles used in industrial "clean areas" to aid in improving environmental contamination control in hatcheries. ACKNOWLEDGMENTS
REFERENCES Beck, W. C , and L. 0. Frey, 1966. The surgeon views contamination control. Part 2. The surgical field considered as a clean work station. Contamination Control, 4 : 13-15. Magwood, S. E., 1964a. Studies in hatchery sanitation. 1. Fluctuations in microbial counts of air in poultry hatcheries. Poultry Sci. 43 : 441-449. Magwood, S. E. 1964b. Studies in hatchery sanitation. 3. The effect of air-borne bacterial populations on contamination of egg and embryo surfaces. Poultry Sci. 43: 1567-1572. Magwood, S. E., and H. Marr, 1964. Studies in hatchery sanitation. 2. A simplified method for assessing bacterial populations on surfaces within hatcheries. Poultry Sci. 43: 1558-1566.
The Effects of Some Acidic and Alkaline Atmospheres on the Changes in p H and Haugh Units in Chicken Eggs RAY G. MCKERLEY, GEORGE W. NEWELL, JOE G. BERRY, GEORGE V. ODELL AND ROBERT D. MORRISON Departments of Poultry Science, Biochemistry, and Mathmatics and Statistics, Oklahoma State University, Stillwater, Oklahoma 74075 (Received for publication June 4, 1966)
E
GG quality deterioration is a problem which has been of vital concern to the egg industry for many years. Efforts to find better methods for maintaining egg quality have been the subject of research for considerable time. There are many factors which affect the quality of an egg as measured by Haugh units. Sharp (1937) in a survey of work done on egg quality deterioration reported that time, temperature, pH, and carbon dioxide were factors affecting the deterioration of egg albumen. Spencer et al. (1956) observed that albumen quality declined linearly with the
logarithm of elapsed time after breakout. In this study it was found that individual hens as well as the age of an egg also influenced the rate of quality loss. Cotterill et al. (1958) reported that as temperature was increased the amount of carbon dioxide lost from an egg likewise increased. Stadelman et al. (1954) observed a linear regression coefficient of —1.1548 for every 10 degrees C. increase in temperature for eggs held in normal atmosphere. The consistency of the thick white of an egg has been shown to be related to its pH. Schaible et al. (1935) observed that the thick white of an egg consisted of many
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 15, 2015
The author is indebted to Mr. M.S. Mitchell, Chief, Production, Poultry Division, Canada Department of Agriculture and his officers especially Mr. J. L. Ruet for co-operation and assistance and to Messrs. E.P. Sally and G. Saumure for technical assistance. The Bio-Graphic Unit of the Scientific Information Section, Research Branch, Department of Agriculture prepared the figures.
The co-operation of the personnel of the hatcheries is acknowledged with thanks.
R. A. CHUNG, E. Y. DAVIS, R. A. MUNDAY AND J. M. J. NING Fatty acid composition of cardiac lipids as affected by dietary cholesterol. Boll. Soc. Ital. Biol. Sper. 38: 1517-1519. Sykes, J. F., J. A. Davidson and F. N. Barrett, 1945. The effect of feeding diethylstilbestrol to cockerels. Poultry Sci. 24: 542-545. Stoffel, W., F. Chu and E. H. Ahrens, Jr., 1959. Analysis of long-chain fatty acids by gas-liquid chromatography. Anal. Chem. 3 1 : 307-308. Taurog, A., F. W. Lorenz, C. Entenman and I. L. Chaikoff, 1944. The effect of diethylstilbestrol on the vitor formation of phospholipids in the liver as measured with radioactive phosphorus. Endocrinology, 35: 483-487. Umberger, E. J., G. H. Goss, K. J. Davis, J. M. Curtis and C. G. Durbin, 1959. Estrogenic residues in the edible tissues of stilbestrol-fattened chickens. Poultry Sci. 38: 118-128. Witten, P. W., and R. T. Holman, 1942. Polyethenoid fatty acid metabolism. VI. Effect of pyridoxine on essential fatty acid conversions. Arch. Biochem. Biophys. 4 1 : 266-273.
Studies in Hatchery Sanitation 4. EFFECT OF REGULAR FLOOR DISINFECTION ON BACTERIAL POPULATIONS IN HATCHERS AND THROUGHOUT THE HATCHERY ENVIRONMENT UNDER COMMERCIAL CONDITIONS S. E. MAGWOOD1 Canada Department of Agriculture, Hull, Quebec (Received for publication June 4, 1966)
I
N OUR previous studies of the bacterial ecology of commercial hatcheries (Magwood, 1964b; and Magwood and Marr, 1964) it was found that the size of the bacterial populations in the hatching machines was directly related to the number of air-borne bacteria in the hatchery. These organisms, which fell on horizontal surfaces such as floors and tables, constituted a reservoir from which they could be made air-borne by employee activity, and, 1 Animal Pathology Division, Health of Animals Branch, Canada Department of Agriculture, Animal Diseases Research Institute, Hull, Quebec.
when drawn into the hatching machines they contaminated successive hatches. The bacteria multiplied rapidly in the nutritious fluids surrounding the emerging chicks. As the chicks dried off, the dust and fluff particles from the young birds, with adherent organisms, were expelled from the hatchers to spread throughout the hatchery rooms. In experimental studies the role of airborne bacteria in the contamination of hatching birds by these organisms was clearly demonstrated by Magwood (1964b). The shell surface of eggs incubated in a heavily contaminated non-commercial
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 15, 2015
- C " by the laying hen. J. Nutrition, 72: 451454. Privett, O. S., M. L. Bland and J. A. Schmit, 1962. Studies on the composition of egg lipid. J. Food Sci. 27: 463-468. Ranney, R. E., and I. L. Chaikoff, 1951. Effect of functional hepatectomy upon estrogen-induced lipemia in the fowl. Am. J. Physiol. 165: 600603. Reinis, A., V. Puchmayer, M. Sulc and A. Duben, 1962. Effect of estrogen treatment on the lipid metabolism of fowl. Sb. Lekar, 64: 340-346. Riddle, O., and D. F. Opdyke, 1941. Hormones capable of increasing liver fat. Science, 9 3 : 440. Reiser, R., 1950. The metabolism of polyunsaturated fatty acids in growing chicks. J. Nutrition, 42: 325-336. Rieckenhoff, I. G., R. T. Holman and G. O. Burr, 1949. Polyethenoid fatty acid metabolism. Effect of dietary polyethenoid fatty acids of rat tissues. Arch. Biochem. 20: 331-340. Rossi, S., M. Martinelli and E. Turchetto, 1962.
HATCHERY SANITATION
The obvious practical application of these findings to hatcheries where sanitary conditions are sub-optimal is to attempt to minimize bacterial contamination in the hatchery environment. Three commercial hatcheries whose sanitary status was known, as judged by the routine microbiological test of hatcher fluff samples, agreed to co-operate in a trial under field conditions. The sanitary status of the three plants, based on previous fluff tests, was as follows: S-good, P-fair, SP-unsatisfactory. MATERIALS AND METHODS
The hatcheries were registered commercial operations whose individual annual production lay between two and four million chicks. In two of the plants, (S and P), four rooms were given experimental treatment; two of these were devoted to sorting, sexing and shipping, the other two were the setter and hatcher rooms. In the third plant (SP) the chick processing area was treated as one room. Each hatchery had more than one kind of floor surface, S had terrazzo and concrete; P had concrete, painted concrete and vinyl asbestos; SP had a wooden floor in the setter room and concrete floors in the others. Seven separate examinations were made
at the S and SP plants and the P hatchery was tested ten times. The initial examinations were made during a hatching period before the disinfectant washing procedure was introduced. At hatchery SP the floor washing was discontinued after the fourth examination and was resumed three months later, before the sixth examination. Following the regular "clean-up" after each hatch the room floors were washed with a detergent-sanitizer* solution, mixed according to the manufacturer's directions, and applied with a mop. The tables and counters were wiped with a similar solution. In addition, other sources which could contribute to air-borne contamination, when located, were eliminated. One of these was the practice at one of the hatcheries of changing soiled chick box pads in the sorting room. Bacteriological populations of the air and of the floors in the rooms were determined during the removal and processing of hatches when the level of contamination was likely to be highest. For determining the counts of air-borne bacteria or "air counts," a TDL slit sampler was employed as described by Magwood (1964a). The values reported the plate counts of colonies per cubic foot of air. For the bacterial populations on the floors the mean counts were estimated by the bacteriological-graphical method described by Magwood and Marr (1964). In this method the "soil" from 0.06 square inch of a floor surface is transferred on a swab to a quadrant of a trypticase glucose extract agar plate (Baltimore Biological Laboratories). This is repeated a total of 8 or 12 times in order to sample many areas of the surface. The mean counts and 95 percent confidence limits are determined by the use of specially designed nomograms. * Breakthrough—Proctor & Gamble, Toronto, Ontario.
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 15, 2015
hatchery picked up large numbers of bacteria from the air circulating through the incubator. During hatching in this same environment, the bacterial populations on the shells, in the air and on various surfaces rose to very high levels. In contrast, when the eggs were transferred after 18 days of incubation to hatch in an uncontaminated environment, the bacteria on the shells died off to almost zero. During and after hatching in this clean environment, practically no bacteria could be recovered from the eggs, the body surfaces of the chicks, the surfaces of the hatcher or the air in the room.
115
116
S. E. MAGWOOD
RESULTS AND DISCUSSION The results at the three plants are charted in Figures 1-3. The values for the room floors have been plotted vertically on a logarithmic scale for each examination. The curve is an approximation of the median of these values for the several examinations. The setter room and the hatcher room floors always had the lowest and highest values, respectively; the counts for the chick processing rooms lay between these extremes. The air counts ranked in the
HATCHERY 'SP'
BACTERIAL COUNTS PER CUBIC FOOT OF AIR , -BACTERIAL COUNTS PER 0.06 SQUARE INCH OF FLOOR
HATCHERY 'S' I AND I AND
BACTERIAL COUNTS PER CUBIC FOOT OF AIR BACTERIAL COUNTS PER 0.06 SQUARE INCH OF FLOOR
FLOOR DISINFECTION SUSPENDED APPROX. 2 MONTHS DISINFECTION RESUMED
0
1
_l_ 1.5
2
3
_l_ 7
MONTHS AFTER START OF INTERMITTENT FLOOR DISINFECTION
FIGS. 1-3. The effect of regular floor disinfection on the bacterial populations of the air and of the floor in three commercial hatcheries. At hatchery P on the nine-month test a marked rise in the counts occurred during dust-producing renovations. Their previous sanitary status, as judged by routine tests of hatchery fluff, was as follows: Sgood, P-fair, SP-unsatisfactory.
a
1 1.5 2 3 MONTHS AFTER START OF REGULAR FLOOR DISINFECTION
7
HATCHERY 'P' & AND h AND
BACTERIAL COUNTS PER CUBIC FOOT OF AIR BACTERIAL COUNTS PER 0.06 SQUARE INCH OF FLOOR 1600-4000
8 20 z S 10
0 2 3 3.5 4 5 9 10 20 21 MONTHS AFTER START OF REGULAR FLOOR DISINFECTION
same order as the floor counts for the rooms and have been plotted in a similar fashion. Due to a technical difficulty it was not possible to utilize the floor counts of the second and third examinations at S and SP and of the third and fourth examinations at P. It seems plausible that the close relationship between air and floor counts would have existed at these examinations also. The initial values at hatchery S were low, possibly due, in part at least, to good design, dense floor surfaces and good housekeeping practices including the use of a floor disinfectant. The values were carried to even lower levels during the trial period. At hatchery P the initial values were
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 15, 2015
OAND
117
HATCHERY SANITATION
At hatchery SP the introduction of floor washing was followed by a marked decline in the air and the floor counts. When this procedure was suspended the counts rose to nearly their former levels, but after resumption of floor washing, they fell to moderate values. Observations reported in Parts 2 and 3 of this series (Magwood and Marr, 1964; and Magwood 1964b) have shown that, in commercial hatcheries, bacterial populations on surfaces inside the hatchers, including the trays, were of moderate size at the end of hatching, even in those plants judged to be less sanitary than desirable. The cleaning and washing of the hatchers reduced this contamination to a lower level. Despite the relatively satisfactory sanitary state of the machines in those plants which had high air and floor counts, successive lots of chicks hatched in these previously clean machines, had very high bacterial counts on the fluff and dust which arose. In contrast, in those plants which had regularly reduced environmental contamination by a "through-the-plant clean-up" chicks were consistently hatched without this marked bacterial multiplication. All of the evidence indicates that sanitizing hatching machines
alone is not sufficient. Reducing the viable microorganisms to low numbers throughout the hatchery premises, as well as in the machines, is the main objective of what can be called hatchery environmental contamination control. When the same problem of air-borne contaminants was encountered in critical assembly areas of space-vehicle components, "clean-room" techniques were developed which included highly efficient filtration of the air and precise control of its flow. These techniques were found to be applicable to contamination control in hospital operating rooms and under simulated operating room conditions Beck and Frey (1966) considered that the method fulfilled the requirements for air asepsis. Although these methods may not be economically feasible for the hatchery industry, the principles and techniques employed in maintaining industrial "clean areas" would greatly aid in designing hatcheries that can more easily be kept biologically clean. SUMMARY Previous experimental studies had shown that air-borne bacteria contaminated chicks during hatching. The reservoir of this contamination was believed to be dust accumulations on the hatchery floor and other horizontal surfaces. Therefore a program of regular floor disinfection was conducted in three commercial hatcheries, and the effect of this measure on bacterial populations of the air and floor surfaces determined at intervals for many months. After the introduction of this program a marked reduction was observed in the size of these populations during the processing of hatches, the time when they are likely to be highest. The results support the conclusion that bacteria in the environment, which on becoming air-borne, contaminate hatching chicks, can be minimized by regularly reducing the counts on horizontal surfaces.
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 15, 2015
much higher than at S, they fell considerably in the early part of the trial, then rose abruptly at the fifth examination. During this fifth test extensive renovations were in progress which may have accounted for the rise. At subsequent tests the values were much reduced but not to the low levels achieved by S. The air exhausted by fans from a building which housed large numbers of growing birds close by the P hatchery may have contributed to their higher counts, particularly during conditions of atmospheric inversion when there is no natural movement of the outside air. In this atmospheric state the counts of air outside hatchery P were found to exceed 200 in one instance (Magwood, 1964a).
118
S. E. MAGWOOD
It should be possible to employ techniques and principles used in industrial "clean areas" to aid in improving environmental contamination control in hatcheries. ACKNOWLEDGMENTS
REFERENCES Beck, W. C , and L. 0. Frey, 1966. The surgeon views contamination control. Part 2. The surgical field considered as a clean work station. Contamination Control, 4 : 13-15. Magwood, S. E., 1964a. Studies in hatchery sanitation. 1. Fluctuations in microbial counts of air in poultry hatcheries. Poultry Sci. 43 : 441-449. Magwood, S. E. 1964b. Studies in hatchery sanitation. 3. The effect of air-borne bacterial populations on contamination of egg and embryo surfaces. Poultry Sci. 43: 1567-1572. Magwood, S. E., and H. Marr, 1964. Studies in hatchery sanitation. 2. A simplified method for assessing bacterial populations on surfaces within hatcheries. Poultry Sci. 43: 1558-1566.
The Effects of Some Acidic and Alkaline Atmospheres on the Changes in p H and Haugh Units in Chicken Eggs RAY G. MCKERLEY, GEORGE W. NEWELL, JOE G. BERRY, GEORGE V. ODELL AND ROBERT D. MORRISON Departments of Poultry Science, Biochemistry, and Mathmatics and Statistics, Oklahoma State University, Stillwater, Oklahoma 74075 (Received for publication June 4, 1966)
E
GG quality deterioration is a problem which has been of vital concern to the egg industry for many years. Efforts to find better methods for maintaining egg quality have been the subject of research for considerable time. There are many factors which affect the quality of an egg as measured by Haugh units. Sharp (1937) in a survey of work done on egg quality deterioration reported that time, temperature, pH, and carbon dioxide were factors affecting the deterioration of egg albumen. Spencer et al. (1956) observed that albumen quality declined linearly with the
logarithm of elapsed time after breakout. In this study it was found that individual hens as well as the age of an egg also influenced the rate of quality loss. Cotterill et al. (1958) reported that as temperature was increased the amount of carbon dioxide lost from an egg likewise increased. Stadelman et al. (1954) observed a linear regression coefficient of —1.1548 for every 10 degrees C. increase in temperature for eggs held in normal atmosphere. The consistency of the thick white of an egg has been shown to be related to its pH. Schaible et al. (1935) observed that the thick white of an egg consisted of many
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 15, 2015
The author is indebted to Mr. M.S. Mitchell, Chief, Production, Poultry Division, Canada Department of Agriculture and his officers especially Mr. J. L. Ruet for co-operation and assistance and to Messrs. E.P. Sally and G. Saumure for technical assistance. The Bio-Graphic Unit of the Scientific Information Section, Research Branch, Department of Agriculture prepared the figures.
The co-operation of the personnel of the hatcheries is acknowledged with thanks.