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Hatchability of Eggs Stored in Plastic-Lined Egg Cases
1278
T. S. NELSON, D. A. HARVILLE AND A. C. WALKER
phosphate to chicks. Poultry Sci. 40: 13211328. Nelson, T. S., and A. C. Walker, 1964. The biological evaluation of phosphorus compounds. Poultry Sci. 43: 94-98.
Nicolaysen, R., 1937. XIV. Studies upon the mode of action of vitamin D. II. The influence of vitamin D on the faecal output of endogenous calcium and phosphorus in the rat. Biochem. J. 3 1 : 107-121.
Hatchability of Eggs Stored in Plastic-Lined Egg Cases D. C. WARREN, H. A. ROFF AND E. LONG Kimber Farms, Inc., Fremont, California
ENEFICIAL results from storing hatching eggs in plastic bags were reported by Becker et al. (1963, 1964, a, b, c), Proudfoot (1964). In some of these tests the numbers of eggs were not large and the period of holding was longer than normally practiced in commercial hatcheries. Gains of as much as 25 percent in hatchability were reported in instances when eggs were held up to 21 days. Also some of the larger reported gains were based on hatchabilities which would be too low for profitable commercial operations. Methods of bagging used in the early experiments were sometimes not suitable for commercial operations and control eggs were stored on open flats instead of in cases.
B
MATERIALS AND METHODS In the work here reported the techniques and practices were of a type suited to commercial hatchery operations. All eggs were placed in refrigerated rooms the day following laying and held at near 15.5°C. and 75 percent relative humidity. The plastic bags utilized were of dimensions approximating those of one-half a standard case and were used as liners enclosing the contents of one end of the case. Results were reported on use of Cryovac and polyethylene liners. The polyethylene was of .002 thickness. A thinner type of polyethylene was tried on a small scale with less satisfactory results.
Air was forced out of any excess space in the bag and the end of the bag was twisted down and tightly sealed with a rubber band. Care was exercised to see that each treatment had a good random sample of eggs. Eggs were placed in collecting cases when passing through the house and then each layer was divided equally among treatments and their controls. One end of a case was used for storing a day's bagged eggs and the opposite end for its control eggs laid the same day. Each day's sample of bagged eggs was usually placed on a tray to themselves as was its control and this pair of trays was kept in adjoining spaces in the incubator. Standard commercial hatchery procedures were followed, removing infertiles at 5 days of incubation for chicken eggs and at 10 days for turkey eggs. No infertiles were broken out so there probably was some early embryonic mortality included in the infertiles. In the tabulation were recorded percentage fertility (as determined by candling), percentage hatch of fertile eggs and percentage marketable chicks (eliminating culls). Percentage marketable chicks was based on total eggs set, thus accounting for any early embryonic mortality which might be included in the eggs classified as infertiles and assuming that sampling eliminated any influence of fertility. Chicken eggs were held 6 to 13 days and turkey eggs 5 to 11 days. These periods include extremes more
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 24, 2015
(Received for publication March 25. 1965)
1279
STORAGE OF HATCHING EGGS
TABLE 1.—Change in percentage fertility, hatchability and marketable chicks or poults resulting from storage of eggs in plastic-lined egg cases. Gains or losses in percentage are expressed as deviations from the control Mean difference
Days held Fertility Hatchability Marketable chicks from total eggs set Number of tests involved Total number of eggs for each treatment Fertility Hatchability Marketable chicks from total eggs set Number of tests involved Total number of eggs for each treatment
commonly encountered hatchery operations.
in
-0.9 +2.2 -0.3 -1.1 +2.3 -1.6 -0.4 +2.5 -1.4 11 12 12 21,935 2,111 2,127
+1.0 +2.5 +2.5 5 863
-0.06 + 1.40 +0.90
Chicken eggs—Polyethylene liners lin +0.8 +0.7 +1.0 -1.0 + 0 . 8 - 0 . 8 - 1 . 0 +9.0 +0.2 +1.8 +3.0 - 1 . 4 +2.2 +0.9 - 0 . 7 + 1.8 + 2 . 7 - 0 . 7 + 3 . 4 + 1 . 9 +9.1 4 4 11 12 12 6 3 717 537 711 1,076 1,446 2,141 2,141
+ 1.2 +4.2 +6.2 5 866
-0.21 +2.50 +3.00
Turkey eggs—Cryovac liners -2.9 2.0 + 1 . 8 + 1 . 6 + 0 . 5 +1.7 - 7 . 2 + 3 . 1 + 0 . 1 + 1.8 + 1 . 7 +3.6 +3.5 -7.1 +2.1 +3.4 +2.4 +1.2 4 4 7 6 5 5 1,202 705 1,733 1,035 930 823
commercial
RESULTS
In Table 1 are given the results obtained with both chicken and turkey eggs. A total of 10,094 chicken eggs were bagged in Cryovac and 10,158 in polyethylene during the 12 tests. In most of the tests the control sample was of the same size as that used with each type of plastic film. Thus each of the two types of plastic used had its own control beside it in the incubator, thereby minimizing any effect of differences in position in the incubator. To the commercial hatcheryman the most significant value listed in Table 1 is the percentage of marketable chicks or poults from total eggs set. There should have been no difference in fertility except for sampling and the techniques of selection of eggs should have kept this at a minimum. The data in Table 1 were expressed as percentage deviation of the bagged sample below or above its control. The difference in fertility between the bagged and unbagged eggs was quite small and indicates that the possible inclusion of early embryonic mortality in the fertility value was not important. The over-all advantage from use of Cryovac bags with
+0.0 +8.4 +5.4 5 1,291
+0.10 + 1.64 + 1.57
chicken eggs was small, being .9 percent increase in marketable chicks and 1.4 percent gain in hatchability over unbagged controls. This difference probably has no statistical significance and certainly little practical significance. The results from use of polyethylene liners for chicken egg cases were somewhat better but showed a smaller increase than those reported by other workers. Better results have been reported from use of Cryovac as compared with polyethylene. Our own mean percentages based on all tests, including eggs of all ages, show little difference between polyethylene and Cryovac bags, being 75.6 percent marketable chicks from eggs stored in polyethylene and 74.6 percent for those in Cryovac bags. In turkey eggs there were 53.1 percent marketable poults from polyethylene bags and 53.7 percent from Cryovac bags. The data on chicken eggs in Table 1 show a larger advantage for poylethylene and the disagreement is probably due to the use of two sets of calculations. The smaller difference resulted from a direct comparison of the mean hatchabilities from use of the two types of plastic. In the table, results were expressed as gains of each type of plastic over its own independent control. Since our differences between the two types
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 24, 2015
Fertility Hatchability Marketable poults from total eggs set Number of tests involved Total number of eggs for each treatment
Chicken eggs—Cryomc liners +2.2 - 3 . 5 •0.3 - 0 . 9 +2.2 + 3 . 7 + 4 . 1 - 1 . 0 +3.2 + 0 . 9 + 2 . 1 - 1 . 9 4 4 6 3 715 714 1,065 534
1280
D. C. WARREN, H. A. ROFF AND E. LONG
liners for holding cases did not entirely prevent the normal decline in hatchability due to increased age of eggs. CONCLUSIONS
Where chicken or turkey eggs are held for not more than 13 days and good holding conditions are provided, the use of plastic-lined containers is of questionable value. If holding conditions are severe such as when shipping eggs long distances or necessity to hold eggs for prolonged periods as reported by others, the use of plastic containers may be advantageous. Hatcheries try to avoid holding eggs longer than a week and the small gains in hatch from use of plastic bags in this test would probably not counterbalance the increased cost of labor and materials. No evidence was found to indicate any deleterious effects of bagging. No significant difference was found between Cryovac or polyethylene bags as liners of holding cases. REFERENCES Becker, W. A., I. V. Spencer and J. L. Smartwood, 1963. Storing hatching eggs in plastic bags. Poultry Sci. 42: 1256. Becker, W. A., I. V. Spencer and J. L. Smartwood, 1964a. The preincubation storage of turkey eggs in closed environments. Poultry Sci. 43: 1526-1534. Becker, W. A., I. V. Spencer and J. L. Smartwood, 1964b. Hatchability of turkey eggs shipped in plastic bags. Poultry Sci. 43: 153 9-1541. Becker, W. A., I. V. Spencer and J. L. Smartwood, 1964c. Modifying the storage environments of hatching eggs using plastic bags. Poultry Sci. 43 : 1303. Proudfoot, F. G., 1964. The effects of plastic packaging and other treatments on hatching egg. Can. J. Animal Sci. 44: 87-95.
JANUARY 5-7. NATIONAL TURKEY FEDERATION CONVENTION AND TURKEY INDUSTRY EXPOSITION, CONRAD HILTON HOTEL, CHICAGO, ILL. JANUARY 24-26. SOUTHEASTERN POULTRY AND EGG ASSOCIATION CONVENTION, MERCHANDISE MART, ATLANTA, GEORGIA
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 24, 2015
of plastic film are small, and in disagreement with other workers, and between turkeys and chickens, we can probably safely assume that there is no significant difference. For turkey eggs we have shown only detailed data based on Cryovac case liners since polyethylene was not used in all turkey tests. The Cryovac bags gave a small increase (1.S7 percent) in percentage of marketable poults from total eggs set and the gain in hatchability was similar. The low hatchability results with turkey eggs are due to the fact that eggs were purposely taken from hens which were near the end of their production period hoping that this might be the period at which bagging of eggs could be most helpful. The same practice was followed to a degree in chicken eggs but decline in hatchability occurring with increased age during the first laying year is less evident in chickens. The results in this test show less advantage than reported by others from use of plastic case liners while holding chicken and turkey hatching eggs. It is true that the holding period was somewhat less than used by others. It is also possible that the holding environment in this test may have • been better than that provided by others. It is true however, that there was in our tests a definite decline in hatchability in both control and bagged eggs as the holding period was lengthened. There was a decline of 7-8 percent yield of marketable chicks between the first two and the last two days of the holding period. So plastic
T. S. NELSON, D. A. HARVILLE AND A. C. WALKER
phosphate to chicks. Poultry Sci. 40: 13211328. Nelson, T. S., and A. C. Walker, 1964. The biological evaluation of phosphorus compounds. Poultry Sci. 43: 94-98.
Nicolaysen, R., 1937. XIV. Studies upon the mode of action of vitamin D. II. The influence of vitamin D on the faecal output of endogenous calcium and phosphorus in the rat. Biochem. J. 3 1 : 107-121.
Hatchability of Eggs Stored in Plastic-Lined Egg Cases D. C. WARREN, H. A. ROFF AND E. LONG Kimber Farms, Inc., Fremont, California
ENEFICIAL results from storing hatching eggs in plastic bags were reported by Becker et al. (1963, 1964, a, b, c), Proudfoot (1964). In some of these tests the numbers of eggs were not large and the period of holding was longer than normally practiced in commercial hatcheries. Gains of as much as 25 percent in hatchability were reported in instances when eggs were held up to 21 days. Also some of the larger reported gains were based on hatchabilities which would be too low for profitable commercial operations. Methods of bagging used in the early experiments were sometimes not suitable for commercial operations and control eggs were stored on open flats instead of in cases.
B
MATERIALS AND METHODS In the work here reported the techniques and practices were of a type suited to commercial hatchery operations. All eggs were placed in refrigerated rooms the day following laying and held at near 15.5°C. and 75 percent relative humidity. The plastic bags utilized were of dimensions approximating those of one-half a standard case and were used as liners enclosing the contents of one end of the case. Results were reported on use of Cryovac and polyethylene liners. The polyethylene was of .002 thickness. A thinner type of polyethylene was tried on a small scale with less satisfactory results.
Air was forced out of any excess space in the bag and the end of the bag was twisted down and tightly sealed with a rubber band. Care was exercised to see that each treatment had a good random sample of eggs. Eggs were placed in collecting cases when passing through the house and then each layer was divided equally among treatments and their controls. One end of a case was used for storing a day's bagged eggs and the opposite end for its control eggs laid the same day. Each day's sample of bagged eggs was usually placed on a tray to themselves as was its control and this pair of trays was kept in adjoining spaces in the incubator. Standard commercial hatchery procedures were followed, removing infertiles at 5 days of incubation for chicken eggs and at 10 days for turkey eggs. No infertiles were broken out so there probably was some early embryonic mortality included in the infertiles. In the tabulation were recorded percentage fertility (as determined by candling), percentage hatch of fertile eggs and percentage marketable chicks (eliminating culls). Percentage marketable chicks was based on total eggs set, thus accounting for any early embryonic mortality which might be included in the eggs classified as infertiles and assuming that sampling eliminated any influence of fertility. Chicken eggs were held 6 to 13 days and turkey eggs 5 to 11 days. These periods include extremes more
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 24, 2015
(Received for publication March 25. 1965)
1279
STORAGE OF HATCHING EGGS
TABLE 1.—Change in percentage fertility, hatchability and marketable chicks or poults resulting from storage of eggs in plastic-lined egg cases. Gains or losses in percentage are expressed as deviations from the control Mean difference
Days held Fertility Hatchability Marketable chicks from total eggs set Number of tests involved Total number of eggs for each treatment Fertility Hatchability Marketable chicks from total eggs set Number of tests involved Total number of eggs for each treatment
commonly encountered hatchery operations.
in
-0.9 +2.2 -0.3 -1.1 +2.3 -1.6 -0.4 +2.5 -1.4 11 12 12 21,935 2,111 2,127
+1.0 +2.5 +2.5 5 863
-0.06 + 1.40 +0.90
Chicken eggs—Polyethylene liners lin +0.8 +0.7 +1.0 -1.0 + 0 . 8 - 0 . 8 - 1 . 0 +9.0 +0.2 +1.8 +3.0 - 1 . 4 +2.2 +0.9 - 0 . 7 + 1.8 + 2 . 7 - 0 . 7 + 3 . 4 + 1 . 9 +9.1 4 4 11 12 12 6 3 717 537 711 1,076 1,446 2,141 2,141
+ 1.2 +4.2 +6.2 5 866
-0.21 +2.50 +3.00
Turkey eggs—Cryovac liners -2.9 2.0 + 1 . 8 + 1 . 6 + 0 . 5 +1.7 - 7 . 2 + 3 . 1 + 0 . 1 + 1.8 + 1 . 7 +3.6 +3.5 -7.1 +2.1 +3.4 +2.4 +1.2 4 4 7 6 5 5 1,202 705 1,733 1,035 930 823
commercial
RESULTS
In Table 1 are given the results obtained with both chicken and turkey eggs. A total of 10,094 chicken eggs were bagged in Cryovac and 10,158 in polyethylene during the 12 tests. In most of the tests the control sample was of the same size as that used with each type of plastic film. Thus each of the two types of plastic used had its own control beside it in the incubator, thereby minimizing any effect of differences in position in the incubator. To the commercial hatcheryman the most significant value listed in Table 1 is the percentage of marketable chicks or poults from total eggs set. There should have been no difference in fertility except for sampling and the techniques of selection of eggs should have kept this at a minimum. The data in Table 1 were expressed as percentage deviation of the bagged sample below or above its control. The difference in fertility between the bagged and unbagged eggs was quite small and indicates that the possible inclusion of early embryonic mortality in the fertility value was not important. The over-all advantage from use of Cryovac bags with
+0.0 +8.4 +5.4 5 1,291
+0.10 + 1.64 + 1.57
chicken eggs was small, being .9 percent increase in marketable chicks and 1.4 percent gain in hatchability over unbagged controls. This difference probably has no statistical significance and certainly little practical significance. The results from use of polyethylene liners for chicken egg cases were somewhat better but showed a smaller increase than those reported by other workers. Better results have been reported from use of Cryovac as compared with polyethylene. Our own mean percentages based on all tests, including eggs of all ages, show little difference between polyethylene and Cryovac bags, being 75.6 percent marketable chicks from eggs stored in polyethylene and 74.6 percent for those in Cryovac bags. In turkey eggs there were 53.1 percent marketable poults from polyethylene bags and 53.7 percent from Cryovac bags. The data on chicken eggs in Table 1 show a larger advantage for poylethylene and the disagreement is probably due to the use of two sets of calculations. The smaller difference resulted from a direct comparison of the mean hatchabilities from use of the two types of plastic. In the table, results were expressed as gains of each type of plastic over its own independent control. Since our differences between the two types
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 24, 2015
Fertility Hatchability Marketable poults from total eggs set Number of tests involved Total number of eggs for each treatment
Chicken eggs—Cryomc liners +2.2 - 3 . 5 •0.3 - 0 . 9 +2.2 + 3 . 7 + 4 . 1 - 1 . 0 +3.2 + 0 . 9 + 2 . 1 - 1 . 9 4 4 6 3 715 714 1,065 534
1280
D. C. WARREN, H. A. ROFF AND E. LONG
liners for holding cases did not entirely prevent the normal decline in hatchability due to increased age of eggs. CONCLUSIONS
Where chicken or turkey eggs are held for not more than 13 days and good holding conditions are provided, the use of plastic-lined containers is of questionable value. If holding conditions are severe such as when shipping eggs long distances or necessity to hold eggs for prolonged periods as reported by others, the use of plastic containers may be advantageous. Hatcheries try to avoid holding eggs longer than a week and the small gains in hatch from use of plastic bags in this test would probably not counterbalance the increased cost of labor and materials. No evidence was found to indicate any deleterious effects of bagging. No significant difference was found between Cryovac or polyethylene bags as liners of holding cases. REFERENCES Becker, W. A., I. V. Spencer and J. L. Smartwood, 1963. Storing hatching eggs in plastic bags. Poultry Sci. 42: 1256. Becker, W. A., I. V. Spencer and J. L. Smartwood, 1964a. The preincubation storage of turkey eggs in closed environments. Poultry Sci. 43: 1526-1534. Becker, W. A., I. V. Spencer and J. L. Smartwood, 1964b. Hatchability of turkey eggs shipped in plastic bags. Poultry Sci. 43: 153 9-1541. Becker, W. A., I. V. Spencer and J. L. Smartwood, 1964c. Modifying the storage environments of hatching eggs using plastic bags. Poultry Sci. 43 : 1303. Proudfoot, F. G., 1964. The effects of plastic packaging and other treatments on hatching egg. Can. J. Animal Sci. 44: 87-95.
JANUARY 5-7. NATIONAL TURKEY FEDERATION CONVENTION AND TURKEY INDUSTRY EXPOSITION, CONRAD HILTON HOTEL, CHICAGO, ILL. JANUARY 24-26. SOUTHEASTERN POULTRY AND EGG ASSOCIATION CONVENTION, MERCHANDISE MART, ATLANTA, GEORGIA
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 24, 2015
of plastic film are small, and in disagreement with other workers, and between turkeys and chickens, we can probably safely assume that there is no significant difference. For turkey eggs we have shown only detailed data based on Cryovac case liners since polyethylene was not used in all turkey tests. The Cryovac bags gave a small increase (1.S7 percent) in percentage of marketable poults from total eggs set and the gain in hatchability was similar. The low hatchability results with turkey eggs are due to the fact that eggs were purposely taken from hens which were near the end of their production period hoping that this might be the period at which bagging of eggs could be most helpful. The same practice was followed to a degree in chicken eggs but decline in hatchability occurring with increased age during the first laying year is less evident in chickens. The results in this test show less advantage than reported by others from use of plastic case liners while holding chicken and turkey hatching eggs. It is true that the holding period was somewhat less than used by others. It is also possible that the holding environment in this test may have • been better than that provided by others. It is true however, that there was in our tests a definite decline in hatchability in both control and bagged eggs as the holding period was lengthened. There was a decline of 7-8 percent yield of marketable chicks between the first two and the last two days of the holding period. So plastic