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The Effect of Sudden Changes of Feed Upon Production
Research Notes THE EFFECT OF SUDDEN CHANGES OF FEED UPON PRODUCTION it has a beneficial effect upon winter egg production. The moist mash was composed of the dry mash moistened with warm water in the proportion of 2 parts of mash to 1 part of water. Approximately one ounce per bird per day was fed. Figure 1 shows the percentage production on a bi-weekly basis for the three groups. Group A increased production rapidly, reaching its peak during the period March 3-16. Group B dropped in production from the time the feed was changed until February 3-16. From then on, production increased rapidly until they reached their peak during the two weeks ending March 16. Group C was even more affected than was Group B although their pattern of production was similar. The difference between B and C can be explained on the basis of mash consumption. Group C averaged only 38.87 gm. of dry mash per bird per day from December 23 to February 2, whereas Group B consumed 52.56 gm. for the same period (moist mash on a dry weight basis included). Consumption on a bird day basis from November 25 to December 22 was 54.47 gm. and 61.32 gm. respectively. Group A consumed 62.00 gm. of mash per bird per day prior to December 22 and after that time increased in accordance with their production. Throughout the test, whole grain was fed morning and evening, the total intake being regulated. This averaged 73.10 gm. per bird per day. In spite of the drop in mash consumption, body weight showed a gradual and rather consistent increase. Group C averaged the smallest gain, 138.35 gm. and A the greatest, 198.25 gm. The fact that neither Group B nor C lost weight 83
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The usual recommendations with regard to the changing from one feed to another, especially for the layers, is to make a gradual change over a period of 7-10 days thus avoiding the possibility of a setback in production. Why a sudden change of feed is harmful is not fully explained but undoubtedly such factors as color, texture and taste have some bearing on the problem. Recently several field reports have been received by this department which indicated that a sudden change from a laying to breeding mash resulted in a decided drop in production. Management was otherwise the same. In order to test the effect of sudden changes of feed upon production, an experiment involving three duplicate pens of 50 birds each was carried out. The test was commenced on November 25, 1944 and was terminated June 8, 1945. Appropriate records on production, body size, egg weight, feed consumption, hatchability and mortality were kept. During the first four weeks all pens were fed the University laying mash. On December 22, the following changes were made. Group A which constituted the control pens was continued on the same diet which was converted to a breeding mash by increasing the vitamins A, D and riboflavin to the recommended levels. Group B was changed from the laying mash to u commercial hatching concentrate. Group C received another commercial concentrate. In addition to the dry mash Groups A and B received a moist mash at noon from the beginning of the experiment. This procedure is common practice in ' Saskatchewan and recent unpublished work has shown that
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RESEARCH NOTES
higher. Mortality immediately following the change of feed was negligible; differences between groups was not noticeable until early March but at that late date could not be attributed to method of feeding. Groups B and C were fed commercial
70 -
§ |
60
50
GROUP A •-GROUP B
40 -
-GROUP C • ^ 2 -wk. \— 30
FIG. 1. The effect of a sudden change of feed upon production.
range being 69.59% in Group C to 73.85% in Group B. One apparent factor due to the change of feed was the incidence of neck moult. Group A showed no signs of a moult, Group B a slight amount (5%) and Group C a considerable degree (18%). The fact that Group B was receiving a wet mash in addition to the dry mash may have had some bearing on the low percentage since their total dry mash consumption was considerably
hatching concentrates throughout the test. In both cases, the manufacturers recommended 3 parts of chopped grains to 1 of concentrate. These recommendations were carried out and the proportion of chopped wheat, oats, and barley was the same as for Group A. Since all the formulae were quite similar, the texture of all three mashes varied only slightly. However the most striking difference was the color. The mash of Group A was much
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can be attributed to the relatively high whole grain intake. Egg size increased throughout the test until early April and from then on, was quite constant. No differences between groups were observed. Hatchability based on three hatches in April and May varied only slightly, the
RESEARCH NOTES
production. The results are evidenced in lowered mash consumption and egg production. Some moulting does occur, the degree depending upon feeding management. The time required to recover from such a setback is usually 8-10 weeks. J. B. O ' N E I X
Department of Poultry Husbandry University of Saskatchewan Saskatoon, Saskatchewan Received for publication, September 4, 1945.
ABNORMAL BLACKENING OF THE FEATHERS OF NEW HAMPSHIRE CHICKS AS THE RESULT OF VITAMIN D DEFICIENCY 1 Since the early work on vitamin D with chickens by Steenbock and Nelson (1923) and Hart, Steenbock, Lepkovsky, and Halpin (1923), the White Leghorn chick has been used predominantly in vitamin D deficiency studies. In a recent study, the results of which are presented here, three lots of day-old New Hampshire chicks were fed the following vitamin D deficient diet (in parts per 100): yellow corn 59, wheat middlings 25, casein 12, yeast 1, calcium carbonate 1, calcium phosphate 1, and iodized salt 1. The control diet in each case contained 400 A.O.A.C. units of " D " activated animal sterol per pound. All chicks were raised in batteries, weighed weekly, and fed ad libitum, except in the third feeding trial in which the amount of feed fed to the control chicks was limited to the amount eaten by the vitamin D deficient group. In the first and second feeding trials, it was observed at the end of the fourth week that a total of 29 out of 30 chickens on the vitamin D deficient diet developed various degrees of abnormal black pig1 Scientific paper No. A 108. Contribution No. 1985 of the Maryland Agricultural Experiment Station (Department of Poultry Husbandry).
mentation at the base of the secondaries and to some extent at the base of the primaries. In some cases this blackening also occurred in the small feathers at the base of the secondaries on the underside of the wing. The degree of blackening appeared to be associated with the degree of rickets. None of the feathers of the 30 control birds receiving vitamin D had abnormal blackening. In the third feeding trial, in which 12 control chicks were limited in feed consumption to the amount eaten by the 12 chicks in the vitamin D deficient group, again only the vitamin D deficient group had the abnormal blackening. This condition was observed in a few chicks as early as the third week, and at five weeks of age all the chicks in the vitamin D deficient group had the abnormal blackening. By the end of the seventh week, this blackening had become more severe and extended into the back feathers in some of the birds. The remaining vitamin D deficient chicks from this feeding trial were then placed on a complete diet. Five weeks later these chickens still had very intense blackening in the secondaries, primaries, and in feathers of most
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more green due to a higher percentage of alfalfa meal, whereas that of Groups B and C was much lighter in color. The type of green feed used in the latter two was a more concentrated product hence contained a lower percentage. No conclusion can be drawn from the standpoint of taste. The sudden changing of feed has a deleterious effect upon production. While color of the mash may not be important in itself, a sudden change does influence
85
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The usual recommendations with regard to the changing from one feed to another, especially for the layers, is to make a gradual change over a period of 7-10 days thus avoiding the possibility of a setback in production. Why a sudden change of feed is harmful is not fully explained but undoubtedly such factors as color, texture and taste have some bearing on the problem. Recently several field reports have been received by this department which indicated that a sudden change from a laying to breeding mash resulted in a decided drop in production. Management was otherwise the same. In order to test the effect of sudden changes of feed upon production, an experiment involving three duplicate pens of 50 birds each was carried out. The test was commenced on November 25, 1944 and was terminated June 8, 1945. Appropriate records on production, body size, egg weight, feed consumption, hatchability and mortality were kept. During the first four weeks all pens were fed the University laying mash. On December 22, the following changes were made. Group A which constituted the control pens was continued on the same diet which was converted to a breeding mash by increasing the vitamins A, D and riboflavin to the recommended levels. Group B was changed from the laying mash to u commercial hatching concentrate. Group C received another commercial concentrate. In addition to the dry mash Groups A and B received a moist mash at noon from the beginning of the experiment. This procedure is common practice in ' Saskatchewan and recent unpublished work has shown that
84
RESEARCH NOTES
higher. Mortality immediately following the change of feed was negligible; differences between groups was not noticeable until early March but at that late date could not be attributed to method of feeding. Groups B and C were fed commercial
70 -
§ |
60
50
GROUP A •-GROUP B
40 -
-GROUP C • ^ 2 -wk. \— 30
FIG. 1. The effect of a sudden change of feed upon production.
range being 69.59% in Group C to 73.85% in Group B. One apparent factor due to the change of feed was the incidence of neck moult. Group A showed no signs of a moult, Group B a slight amount (5%) and Group C a considerable degree (18%). The fact that Group B was receiving a wet mash in addition to the dry mash may have had some bearing on the low percentage since their total dry mash consumption was considerably
hatching concentrates throughout the test. In both cases, the manufacturers recommended 3 parts of chopped grains to 1 of concentrate. These recommendations were carried out and the proportion of chopped wheat, oats, and barley was the same as for Group A. Since all the formulae were quite similar, the texture of all three mashes varied only slightly. However the most striking difference was the color. The mash of Group A was much
Downloaded from https://academic.oup.com/ps/article-abstract/25/1/83/1504410 by 04860000 user on 26 January 2019
can be attributed to the relatively high whole grain intake. Egg size increased throughout the test until early April and from then on, was quite constant. No differences between groups were observed. Hatchability based on three hatches in April and May varied only slightly, the
RESEARCH NOTES
production. The results are evidenced in lowered mash consumption and egg production. Some moulting does occur, the degree depending upon feeding management. The time required to recover from such a setback is usually 8-10 weeks. J. B. O ' N E I X
Department of Poultry Husbandry University of Saskatchewan Saskatoon, Saskatchewan Received for publication, September 4, 1945.
ABNORMAL BLACKENING OF THE FEATHERS OF NEW HAMPSHIRE CHICKS AS THE RESULT OF VITAMIN D DEFICIENCY 1 Since the early work on vitamin D with chickens by Steenbock and Nelson (1923) and Hart, Steenbock, Lepkovsky, and Halpin (1923), the White Leghorn chick has been used predominantly in vitamin D deficiency studies. In a recent study, the results of which are presented here, three lots of day-old New Hampshire chicks were fed the following vitamin D deficient diet (in parts per 100): yellow corn 59, wheat middlings 25, casein 12, yeast 1, calcium carbonate 1, calcium phosphate 1, and iodized salt 1. The control diet in each case contained 400 A.O.A.C. units of " D " activated animal sterol per pound. All chicks were raised in batteries, weighed weekly, and fed ad libitum, except in the third feeding trial in which the amount of feed fed to the control chicks was limited to the amount eaten by the vitamin D deficient group. In the first and second feeding trials, it was observed at the end of the fourth week that a total of 29 out of 30 chickens on the vitamin D deficient diet developed various degrees of abnormal black pig1 Scientific paper No. A 108. Contribution No. 1985 of the Maryland Agricultural Experiment Station (Department of Poultry Husbandry).
mentation at the base of the secondaries and to some extent at the base of the primaries. In some cases this blackening also occurred in the small feathers at the base of the secondaries on the underside of the wing. The degree of blackening appeared to be associated with the degree of rickets. None of the feathers of the 30 control birds receiving vitamin D had abnormal blackening. In the third feeding trial, in which 12 control chicks were limited in feed consumption to the amount eaten by the 12 chicks in the vitamin D deficient group, again only the vitamin D deficient group had the abnormal blackening. This condition was observed in a few chicks as early as the third week, and at five weeks of age all the chicks in the vitamin D deficient group had the abnormal blackening. By the end of the seventh week, this blackening had become more severe and extended into the back feathers in some of the birds. The remaining vitamin D deficient chicks from this feeding trial were then placed on a complete diet. Five weeks later these chickens still had very intense blackening in the secondaries, primaries, and in feathers of most
Downloaded from https://academic.oup.com/ps/article-abstract/25/1/83/1504410 by 04860000 user on 26 January 2019
more green due to a higher percentage of alfalfa meal, whereas that of Groups B and C was much lighter in color. The type of green feed used in the latter two was a more concentrated product hence contained a lower percentage. No conclusion can be drawn from the standpoint of taste. The sudden changing of feed has a deleterious effect upon production. While color of the mash may not be important in itself, a sudden change does influence
85