- Email: [email protected]
Feeding Hens During Alternating a.m. and p.m. Time Blocks to Induce Zero Egg Production During the Molt
2006 Poultry Science Association, Inc.
Feeding Hens During Alternating a.m. and p.m. Time Blocks to Induce Zero Egg Production During the Molt P. Ruszler1 and C. Novak
Primary Audience: Extension, Egg Industry, and Production Workers, Researchers SUMMARY There is a need to evaluate the position paper and guidelines set forth by the United Egg Producers (Washington, DC) and the American Veterinary Medical Association (Schaumburg, IL) on feeding practices and nutrient levels provided during a molt. This pilot study was undertaken to learn if a complete cessation of lay could be achieved with daily feeding while using an alternate morning and evening feeding schedule. This was an effort to mimic the fast that a bird experiences in a natural setting. The hens were fed the amount they would eat in 4 h during the morning one day and again the evening of the next day. Some hens ceased production in the third week and others in the fourth week, with zero production for all hens occurring during the fifth week. The return to 50% egg production was achieved from wk 7 to 8. Peak egg production occurred from the eleventh to twelfth weeks postmolt, reaching a level only 5 to 6 percentage points below the first cycle. This feeding protocol resulted in complete cessation of lay, allowing for a more uniform and complete restoration of the ovarian and oviductal tissues. This restoration is necessary for an effective economical postmolt period of egg production. Key words: egg production, induced molt, low nutrient diets, nonfasting 2006 J. Appl. Poult. Res. 15:525–530
DESCRIPTION OF PROBLEM When carried out properly, induced molting of laying hens by the industry can be effective for economical egg production. The most effective method that will generate optimal egg production for the longest period has been one using a period of feed withdrawal. Most commercial egg producers use molting programs that have some period of feed withdrawal because they are effective and easily followed. Concern for welfare of the hen during the molt has been expressed by poultry scientists, commercial poultrymen, and others in recent years. Even though a bird going through a natu1
Corresponding author: [email protected]
ral molt will reject feed for an extended period, as reported by Mrosovsky and Sherry [1], there is concern centering upon whether it is harmful to initiate a molt before the bird is physiologically ready. This concern, plus the desire by some for a simple method to molt hens, has led to extensive research into methods that do not require feed deprivation. The current American Veterinary Medical Association’s Policy Statement and Guidelines [2] on induced molting states: “Acceptable (molting) practices include reduction of photoperiod ‘day length’ and dietary restrictions that result in cessation of egg production, but water should not be withdrawn.
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Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg 24061
JAPR: Research Report
526
a molt protocol would result in optimal postmolt performance. This would also address the concern of mechanically handling a diet containing high levels of bulky nutrients.
MATERIALS AND METHODS Four strains of Leghorn hens, 66 wk old, were housed 3 per cage at 464 cm2 for a period of 12 wk in a light- and temperature-controlled facility. The strains used were Bovans White [12], Lohmann LSL-LITE [13], Hy-Line W-98 [14], and Hy-Line W-36 [15]. A 17% CP, 2,795 kcal/kg (1,270 kcal/lb) layer diet was provided ad libitum starting on d 29 of the molt. Water was provided ad libitum via nipple drinkers. The daylength was reduced from 16 to 11 h/d, commencing 2 wk before the initiation of the molt through d 32 of the molt. The daylength was increased by 1 h on d 33 and 38, 0.5 h on d 43, and every fifth day thereafter until a 16-h day was restored at d 68 postmolt. The treatments were 3 different molting diets consisting of either a low-energy (LE) 9.7% CP, 1,100 kcal/kg (500 kcal/lb) molt diet; highenergy (HE) 9.7% CP, 1,430 kcal/kg (650 kcal/ lb) molt diet; or a commercial (COM) 14% CP, 2,750 kcal/kg (1,250 kcal/lb) molt diet. The amount of layer feed consumed in 4 h was measured before onset of the molt period. This measurement was taken on 2 consecutive days, once in the morning and once in the afternoon, to determine the mean value. That amount, 36 g/ bird measured by volume, was provided to hens randomly assigned to the 3 treatments once each day at 0800 h on d 1, at 1600 h on d 2, and again at 0800 h on d 3 for the first 28 d of the molt. The physical condition of the birds was evaluated daily for any necessary adjustments in feeding. Egg production and mortality were recorded daily. Body weight and feed intake were measured each week. Data were analyzed using the GLM procedure [16]. Means found to be significantly different from each other were identified using Duncan’s multiple range test [17]. An arc sine procedure was applied to egg production data.
RESULTS AND DISCUSSION Feed Intake The diets contained different combinations of soy hulls and wheat bran that totaled from 70
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Intermittent feeding of diets of low nutrient density is recommended rather than total feed withdrawal. The AVMA encourages ongoing research into the effect of various methods of induced molting on the performance and wellbeing of laying chickens.” United Egg Producers has a position statement for induced molting [3], which states: “Producers and researchers are encouraged to work together to develop alternatives to feed withdrawal for molting. Until such time that these alternatives are available, the shortest period of feed withdrawal possible should be used to accomplish the goal of rejuvenating the hen’s egg production capabilities and overall welfare.” Some of the alternatives requested by United Egg Producers [3] have been reported by Ruszler and Minear [4] in 1997, in which they learned that a low-energy and high-fiber molt diet fullfed to hens after a 4-d feed withdrawal induced molt that was equally effective as other commercial molts using longer periods of feed withdrawal. Minear [5] learned that low-energy and high-fiber diets fed to commercial flocks with no period of feed withdrawal would induce a molt. However, complete cessation of lay did not occur with this method, resulting in lessthan-optimal postmolt performance. Work reported by Biggs et al. in 2003 [6] and again in 2004 [7] showed similar results. It was reported by Ruszler et al. [8, 9] and Ruszler and Novak [10] that hens full-fed a molt diet of 9.5% CP and 1,430 kcal/kg with no period of feed withdrawal did achieve zero egg production. Limited availability of food is one of the factors triggering seasonal fasting of wild avian species, resulting in a temporary condition of anorexia according to Anderson and Jones [11]. The same phenomenon occurs when molting with periods of complete feed withdrawal. Certain animal welfare activists promote the concept that when hens are not being fed each day, they are being subjected to a type of starvation. This pilot study was designed to address that concern and still trigger a viable molt very similar to that caused by natural fasting. The study was designed to determine if a molt resulting in zero production could be induced by feeding a commercial molt diet each day as well as diets with low energy but in alternating morning and afternoon periods. It was necessary to learn if such
RUSZLER AND NOVAK: ALTERNATE A.M. AND P.M. MOLT FEEDING
527
Table 1. Feed consumption for treatments (g/bird per d) Week 1
Treatment HE LE COM
1 38 35 37
2
3 a
74 78a 24b
38 39 35
4 xy
45 42y 47x
5
6
7 to 12
161 153 159
113 122 120
121 123 124
Means in wk 2 with different superscripts differ significantly (P < 0.001). Means in wk 4 with different superscripts differ significantly (P < 0.05). 1 HE = high energy, 9.7% CP, 1,430 kcal/kg; LE = low energy, 9.7% CP, 1,100 kcal/kg; COM = commercial, 14% CP, 2,750 kcal/kg. a,b
to 80% of the diet. Some commercial operations may not be able to handle that level of those 2 ingredients either in the milling of feed or passage through the feeding system. Feed withdrawal periods have ranged from 14 to 16 d, as recommended by Brake and Carey [18] to 6 d by Ruszler [19]. Ruszler [20] reduced the period to 4 d in 1996, which was followed by a 28-d period of increasing feed levels going from 25% of the hen’s maintenance needs up to 90% of its full production requirements. This more closely follows the natural pattern of feed intake for developing pullets [12, 13, 14, 15] than does full feeding after 14 d of total feed withdrawal. Measuring the daily feed rations of 36 g by volume instead of weighing each day was used to simulate the distribution in commercial layer facilities by mechanical means. The period of 4 h was chosen because optimizing the rate of growth in broilers is done by feeding every 4 h. Denbow [21] states: “In chickens insoluble markers first appear in the excreta 1.6 to 2.6 h after ingestion. However, mean retention time is a better indicator of transit time than is time to initial appearance of the marker. Mean retention time for insoluble markers can vary from 5 to 9 h depending on the nature of the ingesta and its size.” Work reported by Imabayashi et al. [22] found that half of the label was excreted from the chicken within 4 to 5 h. Because this was an untested feeding protocol, it initially was evaluated daily, and adjustments were made weekly for the first 4 wk. The physical appearance and activity of the birds on the HE and LE diets were observed to be inferior to those of the COM-fed birds during wk 1, so their ration was doubled in wk 2 (Table 1). Their BW and egg production did not fall as expected at the higher level of intake during the second
week, so the level was reduced back to the original amount during the third week. The amount of ration fed was increased 25% for all 3 treatments during the fourth week. The significantly reduced level of feed consumed by the COM treatment during the second week was apparently due to an unexplained feeding error. The usual compensatory spike in feed intake after returning to full feed occurred during wk 5 but returned to more normal levels during wk 6 through 12. Significant strain differences in feed intake occurred during the 8 wk of postmolt production. Hy-Line W-36 birds consumed a mean of 109 g/bird per day compared with 129, 130, and 135 g/bird per day for Lohmann, Bovans, and HyLine W-98 hens, respectively (P < 0.05). The lower level of intake for the W-36 birds was consistent for all 8 wk. This may be 1 reason the breeder management guide for the Hy-Line W-36 [15] calls for higher nutrient levels in their diet than was used in this trial. BW The BW of the birds in the 3 treatments through the first 3 wk were related to their beginning values (Table 2). The birds in the HE and LE treatments lost less weight than the COM birds during wk 1 and 2. They lost almost no weight during wk 2 due to the extra feed provided. The rate of weight loss increased in wk 3 to about 1.5 times the rate during wk 1 and 2 when only the original amount of feed (≈36 g/ bird per day) was provided to the birds. The birds in the LE and COM treatments consistently lost more weight than the HE birds during the first 4 wk, with the LE treatment birds eventually losing 33.2% compared with 30.2 and 28.1% for the COM and HE, respectively. This was similar to the BW loss reported by Ruszler [23]
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x,y
JAPR: Research Report
528 Table 2. Body weight (g) and BW change (%) for strain and treatment Week1 Treatment2
Initial
1
2 a
1,770
LE
1,752
COM
1,740
Strain Bovans
1,697b
W-983
1,925a
Lohmann
1,737b
W-363
1,658b
4 a
a
5
12
1,488 –15.9 1,433a –18.2 1,368b –21.4
1,468 –17.1 1,421a –18.9 1,308b –24.8
1,334 –24.6 1,265ab –27.8 1,230b –29.3
1,273 –28.1 1,171b –33.2 1,208b –30.6
1,514 –14.5 1,485 –15.2 1,498 –13.9
1,869 +5.6 1,859 +6.1 1,804 +3.7
1,328b –21.7 1,555a –19.2 1,407b –19.0 1,389b –16.2
1,309b –22.9 1,519a –21.1 1,367b –21.3 1,365b –17.7
1,175c –30.8 1,369a –28.9 1,239bc –28.7 1,283b –22.6
1,141c –32.8 1,291a –32.9 1,171bc –32.6 1,235ab –25.5
1,401b –17.4 1,625a –15.6 1,494b –14.0 1,439b –13.2
1,750b +3.1 2,014a +4.6 1,805b +3.9 1,768b +6.6
Body weight means with different superscripts in columns differ significantly (P < 0.001). Upper number is BW presented in grams. Lower italicized number is percentage of change from initial BW (resented for comparison only; not analyzed). 2 HE = high energy, 9.7% CP, 1,430 kcal/kg; LE = low energy, 9.7% CP, 1,100 kcal/kg; COM = commercial, 14% CP, 2,750 kcal/kg. 3 Hy-Line strains. a–c 1
but was considerably (40 to 45%) more than Ruszler et al. [9] or Ruszler and Novak [10] reported. Each treatment regained BW at a similar rate, with the COM treatment gaining the least numerically. The 4 strains followed the same loss pattern for BW as the treatments. The Hy-Line W-98 strain remained significantly heavier than the others. The Hy-Line W-36 strain experienced the lower rate of BW loss but regained the greater amount on a percentage basis (Table 2).
Egg Production The generally accepted periods of no (<3%) egg production ranged from 7 to 21 d in length, beginning in the second week of molt. Postmolt production performance was numerically less than or equal to molts using periods of feed withdrawal. Actual zero production was not achieved until wk 5 for both treatments and strains except for the LE treatment in wk 4 (Table 3). The extra amount of feed given during
Table 3. Percentage weekly hen-day production for treatments and strains Week 1
Treatment
1
2
3
4
5
6
7
8
HE LE COM Strain Bovans W-982 Lohmann W-362
48 48 49
3.3 3.9 3.5
3.1 1.8 0.5
0.8 0.0 0.8
0 0 0
7.5 3.5 5.3
43.1 43.7 50.4
68.4b 80.3a 75.8ab
43 50 48 51
4.7 3.3 2.7 3.9
2.1 1.8 2.5 0.9
0.5 0.9 0.3 0.3
0 0 0 0
10.5a 7.1ab 3.5b 2.4b
52.9a 57.7a 53.8a 21.7b
86.2a 81.0a 83.8a 53.3b
9
10
11
12
80.6 85.5 85.8
88.1 89.3 90.4
88.5 89.2 91.5
90.6 90.0 92.0
93.1a 85.4b 88.4ab 72.6c
92.6 89.6 90.2 86.0
92.4 88.7 92.4 86.6
92.4 88.4 93.8 89.6
Means with different superscripts in columns differ significantly (P < 0.001). HE = high energy, 9.7% CP, 1,430 kcal/kg; LE = low energy, 9.7% CP, 1,100 kcal/kg; COM = commercial, 14% CP, 2,750 kcal/kg. 2 Hy-Line strains. a–c 1
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HE
3 a
RUSZLER AND NOVAK: ALTERNATE A.M. AND P.M. MOLT FEEDING Table 4. Cumulative eggs per hen housed for treatments and strains Week 1 to 5
1 to 9
1 to 12
HE LE COM Strain Bovans W-982 Lohmann W-362
3.8 3.9 3.7
17.5 18.5 18.6
35.9 36.9 37.2
3.6 3.9 3.8 3.9
20.1a 20.1a 19.1a 14.4b
38.2a 38.8a 37.6a 32.8b
a,b
Means with different superscripts in columns differ significantly (P < 0.001). 1 HE = high energy, 9.7% CP, 1,430 kcal/kg; LE = low energy, 9.7% CP, 1,100 kcal/kg; COM = commercial, 14% CP, 2,750 kcal/kg. 2 Hy-Line strains.
wk 2 appears to be the reason that egg production did not drop below 1% during wk 3, except for the COM-fed birds and the Hy-Line W-36 strain. This shows that the equivalent of zero production (<3%) can be achieved with this feeding protocol. It is necessary for production to drop to this level to insure a uniform molt over the entire flock and to allow enough time of rest from production for the ovarian and oviductal tissues to rejuvenate properly [11, 23, 24]. Egg production would have probably dropped below
1% during wk 3 if the amount of feed had not been increased during wk 2 for the HE- and LEfed birds. None of the treatments showed significant differences in the rate of return to peak hen-day egg production after the molt. It is not certain that peak production by treatments was attained at 12 wk, because the trial had to be terminated at that time. However, this would appear to be true, because these hens peaked at 94 to 96% during the first lay cycle. The Hy-Line W-36 strain returned to production at a significantly slower rate than the other 3 strains until wk 10. This reflects the lower feed intake by the HyLine W-36, which did not satisfy their higher nutrient density requirements. There were no significant differences in the cumulative number of eggs produced on a hen-housed basis except between the W-36 strain and the other 3 strains (Table 4). This difference was consistent during the whole trial. There was not a strain by treatment interaction for egg production during this trial. Mortality Mortality was not an important factor in this study. Three birds died in the first 3 wk, 1 each from Bovans HE, Lohmann LE, and Lohmann COM treatments.
CONCLUSIONS AND APPLICATIONS 1. Daily feeding hens at alternating a.m./p.m. time blocks will induce a complete molt. 2. Zero egg production was attained in all hens, allowing more uniform tissue rejuvenation during the rest period. 3. Molting diets containing 9.7% CP with 1,100 or 1,430 kcal/kg of energy are similar in inducing a successful molt. 4. The energy needs of the flock should dictate the energy level used. 5. Alternating time block feeding could be the method of choice for molting a flock producing at a level near 80% or more to comply with feeding a molt diet each day. 6. The Hy-Line W-36 strain may have performed better if fed a layer diet with nutrient levels recommended in the breeder management guide. 7. The technique is worthy of a full-scale study. Such a study may need to compare the amount fed in each molt feeding period to be equivalent to that amount consumed before initiation of the molt during a 5-h period and 6-h period vs. a 4-h period. A more median nutrient level diet such as 11.85% CP, 1,925 kcal/kg, in addition to the diets used in this study, may offer a better insight of the nutrient levels needed.
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Treatment1
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REFERENCES AND NOTES 1. Mrosovsky, N., and D. F. Sherry. 1980. Animal anorexias. Science 207:837–842. 2. American Veterinary Medical Association. 2002. Animal practices guideline – Poultry. Page 77 in AVMA Membership Directory and Resource Manual. Am. Vet. Med. Assoc., Schaumburg, IL. 3. United Egg Producers. 2002. Molting. Pages 8–9 in Animal Husbandry Guidelines. United Egg Prod., Alpharetta, GA.
5. Minear, L. R. 1999. Southern States Research, Richmond, VA. Personal communication. 6. Biggs, P. E., M. W. Douglas, K. W. Koelkebeck, and C. M. Parsons. 2003. Evaluation of nonfeed removal methods for molting programs. Poult. Sci. 82:749–753. 7. Biggs, P. E., M. E. Persia, K. W. Koelkebeck, and C. M. Parsons. 2004. Further evaluation of nonfeed removal methods for molting programs. Poult. Sci. 83:745–752. 8. Ruszler, P. L., C. F. Honaker, L. R. Minear, and C. L. Novak. 2004. Comparison of four commercial molt programs with and without feed restriction procedures. Page 15 in Abstracts. South. Poult. Sci. Soc., USPEA, Atlanta, GA. 9. Ruszler, P. L., C. F. Honaker, and C. L. Novak. 2004. The comparison of two full fed molt programs with two commercial restricted fed molt programs. Page 15 in Abstracts. South. Poult. Sci. Soc., USPEA, Atlanta, GA. 10. Ruszler, P. L., and C. L. Novak. 2005. Determining protein and energy levels needed for full fed molting procedures. Poult. Sci. 84(Suppl. 1):80. (Abstr.) 11. Anderson, K. E., and D. R Jones. Review on the Theological, Philosophical and Physiological effects of fasting across species. Calif. Egg Comm., Upland, CA. 12. Bovans. 1991. Bovans White Management Guide. Centurion Poult. Inc., Bogart, GA. 13. Lohmann North American Edition. 2002. Lohmann LSLLITE Layer Management Guide. Lohmann Tierzucht Inc., Sycamore, IL.
15. Hy-Line International. 2000. Hy-Line Variety W-36 Commercial Management Guide 2000–2001. Hy-Line Int., West Des Moines, IA. 16. SAS Institute. 2001. SAS User’s Guide: Statistics. Version 8 ed. SAS Inst. Inc., Cary, NC. 17. Duncan, D. B. 1955. Multiple range and multiple F-tests. Biometrics 11:1–42. 18. Brake, J. T., and J. B. Carey. 1983. Induced molting of commercial layers. North Carolina Agricultural Extension Service Poultry Science and Technical Guide No. 10. N. C. Agric. Ext. Serv., Raleigh, NC. 19. Ruszler, P. L. 1984. The keys to successful force molting. Virginia Cooperative Extension Service Publ. 408-026 (rev.), Blacksburg, VA. 20. Ruszler, P. L. 1996. The keys to successful induced molting of Leghorn-type hens. Virginia Cooperative Extension Service Publ. 408-026 (revised). Blacksburg, VA. 21. Denbow, D. M. 2000. Gastrointestinal anatomy and physiology. Page 313 in Sturkie’s Avian Physiology. 5th ed. G. Causey Whittow, ed. Acad. Press, New York, NY. 22. Imabayashi, K., M. Kametaka, and T. Hatano. 1956. Studies on digestion in the domestic fowl. Tokyo J. Agric. Res. 2:99. 23. Ruszler, P. L. 1986. Comparison of certain methods for induced molting of layers. Pages 17–33 in Proc. Maryland Nutr. Conf., Baltimore, MD. Univ. Maryland, College Park. 24. Brake, J. T. 1993. Recent advances in induced molting. Poult. Sci. 72:929–931.
Acknowledgments We thank Christa Honaker for her statistical and technical assistance and Brenda Caldwell for technical assistance.
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4. Ruszler, P. L., and L. R. Minear. 1997. Comparison of induced molts using periods of four vs. ten days feed withdrawal. Poult. Sci. 76(Suppl. 1):104. (Abstr.)
14. Hy-Line International. 2001. Hy-Line Variety W-98 Commercial Management Guide 2001–2003. Hy-Line Int., West Des Moines, IA.
Feeding Hens During Alternating a.m. and p.m. Time Blocks to Induce Zero Egg Production During the Molt P. Ruszler1 and C. Novak
Primary Audience: Extension, Egg Industry, and Production Workers, Researchers SUMMARY There is a need to evaluate the position paper and guidelines set forth by the United Egg Producers (Washington, DC) and the American Veterinary Medical Association (Schaumburg, IL) on feeding practices and nutrient levels provided during a molt. This pilot study was undertaken to learn if a complete cessation of lay could be achieved with daily feeding while using an alternate morning and evening feeding schedule. This was an effort to mimic the fast that a bird experiences in a natural setting. The hens were fed the amount they would eat in 4 h during the morning one day and again the evening of the next day. Some hens ceased production in the third week and others in the fourth week, with zero production for all hens occurring during the fifth week. The return to 50% egg production was achieved from wk 7 to 8. Peak egg production occurred from the eleventh to twelfth weeks postmolt, reaching a level only 5 to 6 percentage points below the first cycle. This feeding protocol resulted in complete cessation of lay, allowing for a more uniform and complete restoration of the ovarian and oviductal tissues. This restoration is necessary for an effective economical postmolt period of egg production. Key words: egg production, induced molt, low nutrient diets, nonfasting 2006 J. Appl. Poult. Res. 15:525–530
DESCRIPTION OF PROBLEM When carried out properly, induced molting of laying hens by the industry can be effective for economical egg production. The most effective method that will generate optimal egg production for the longest period has been one using a period of feed withdrawal. Most commercial egg producers use molting programs that have some period of feed withdrawal because they are effective and easily followed. Concern for welfare of the hen during the molt has been expressed by poultry scientists, commercial poultrymen, and others in recent years. Even though a bird going through a natu1
Corresponding author: [email protected]
ral molt will reject feed for an extended period, as reported by Mrosovsky and Sherry [1], there is concern centering upon whether it is harmful to initiate a molt before the bird is physiologically ready. This concern, plus the desire by some for a simple method to molt hens, has led to extensive research into methods that do not require feed deprivation. The current American Veterinary Medical Association’s Policy Statement and Guidelines [2] on induced molting states: “Acceptable (molting) practices include reduction of photoperiod ‘day length’ and dietary restrictions that result in cessation of egg production, but water should not be withdrawn.
Downloaded from http://japr.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on April 20, 2015
Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg 24061
JAPR: Research Report
526
a molt protocol would result in optimal postmolt performance. This would also address the concern of mechanically handling a diet containing high levels of bulky nutrients.
MATERIALS AND METHODS Four strains of Leghorn hens, 66 wk old, were housed 3 per cage at 464 cm2 for a period of 12 wk in a light- and temperature-controlled facility. The strains used were Bovans White [12], Lohmann LSL-LITE [13], Hy-Line W-98 [14], and Hy-Line W-36 [15]. A 17% CP, 2,795 kcal/kg (1,270 kcal/lb) layer diet was provided ad libitum starting on d 29 of the molt. Water was provided ad libitum via nipple drinkers. The daylength was reduced from 16 to 11 h/d, commencing 2 wk before the initiation of the molt through d 32 of the molt. The daylength was increased by 1 h on d 33 and 38, 0.5 h on d 43, and every fifth day thereafter until a 16-h day was restored at d 68 postmolt. The treatments were 3 different molting diets consisting of either a low-energy (LE) 9.7% CP, 1,100 kcal/kg (500 kcal/lb) molt diet; highenergy (HE) 9.7% CP, 1,430 kcal/kg (650 kcal/ lb) molt diet; or a commercial (COM) 14% CP, 2,750 kcal/kg (1,250 kcal/lb) molt diet. The amount of layer feed consumed in 4 h was measured before onset of the molt period. This measurement was taken on 2 consecutive days, once in the morning and once in the afternoon, to determine the mean value. That amount, 36 g/ bird measured by volume, was provided to hens randomly assigned to the 3 treatments once each day at 0800 h on d 1, at 1600 h on d 2, and again at 0800 h on d 3 for the first 28 d of the molt. The physical condition of the birds was evaluated daily for any necessary adjustments in feeding. Egg production and mortality were recorded daily. Body weight and feed intake were measured each week. Data were analyzed using the GLM procedure [16]. Means found to be significantly different from each other were identified using Duncan’s multiple range test [17]. An arc sine procedure was applied to egg production data.
RESULTS AND DISCUSSION Feed Intake The diets contained different combinations of soy hulls and wheat bran that totaled from 70
Downloaded from http://japr.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on April 20, 2015
Intermittent feeding of diets of low nutrient density is recommended rather than total feed withdrawal. The AVMA encourages ongoing research into the effect of various methods of induced molting on the performance and wellbeing of laying chickens.” United Egg Producers has a position statement for induced molting [3], which states: “Producers and researchers are encouraged to work together to develop alternatives to feed withdrawal for molting. Until such time that these alternatives are available, the shortest period of feed withdrawal possible should be used to accomplish the goal of rejuvenating the hen’s egg production capabilities and overall welfare.” Some of the alternatives requested by United Egg Producers [3] have been reported by Ruszler and Minear [4] in 1997, in which they learned that a low-energy and high-fiber molt diet fullfed to hens after a 4-d feed withdrawal induced molt that was equally effective as other commercial molts using longer periods of feed withdrawal. Minear [5] learned that low-energy and high-fiber diets fed to commercial flocks with no period of feed withdrawal would induce a molt. However, complete cessation of lay did not occur with this method, resulting in lessthan-optimal postmolt performance. Work reported by Biggs et al. in 2003 [6] and again in 2004 [7] showed similar results. It was reported by Ruszler et al. [8, 9] and Ruszler and Novak [10] that hens full-fed a molt diet of 9.5% CP and 1,430 kcal/kg with no period of feed withdrawal did achieve zero egg production. Limited availability of food is one of the factors triggering seasonal fasting of wild avian species, resulting in a temporary condition of anorexia according to Anderson and Jones [11]. The same phenomenon occurs when molting with periods of complete feed withdrawal. Certain animal welfare activists promote the concept that when hens are not being fed each day, they are being subjected to a type of starvation. This pilot study was designed to address that concern and still trigger a viable molt very similar to that caused by natural fasting. The study was designed to determine if a molt resulting in zero production could be induced by feeding a commercial molt diet each day as well as diets with low energy but in alternating morning and afternoon periods. It was necessary to learn if such
RUSZLER AND NOVAK: ALTERNATE A.M. AND P.M. MOLT FEEDING
527
Table 1. Feed consumption for treatments (g/bird per d) Week 1
Treatment HE LE COM
1 38 35 37
2
3 a
74 78a 24b
38 39 35
4 xy
45 42y 47x
5
6
7 to 12
161 153 159
113 122 120
121 123 124
Means in wk 2 with different superscripts differ significantly (P < 0.001). Means in wk 4 with different superscripts differ significantly (P < 0.05). 1 HE = high energy, 9.7% CP, 1,430 kcal/kg; LE = low energy, 9.7% CP, 1,100 kcal/kg; COM = commercial, 14% CP, 2,750 kcal/kg. a,b
to 80% of the diet. Some commercial operations may not be able to handle that level of those 2 ingredients either in the milling of feed or passage through the feeding system. Feed withdrawal periods have ranged from 14 to 16 d, as recommended by Brake and Carey [18] to 6 d by Ruszler [19]. Ruszler [20] reduced the period to 4 d in 1996, which was followed by a 28-d period of increasing feed levels going from 25% of the hen’s maintenance needs up to 90% of its full production requirements. This more closely follows the natural pattern of feed intake for developing pullets [12, 13, 14, 15] than does full feeding after 14 d of total feed withdrawal. Measuring the daily feed rations of 36 g by volume instead of weighing each day was used to simulate the distribution in commercial layer facilities by mechanical means. The period of 4 h was chosen because optimizing the rate of growth in broilers is done by feeding every 4 h. Denbow [21] states: “In chickens insoluble markers first appear in the excreta 1.6 to 2.6 h after ingestion. However, mean retention time is a better indicator of transit time than is time to initial appearance of the marker. Mean retention time for insoluble markers can vary from 5 to 9 h depending on the nature of the ingesta and its size.” Work reported by Imabayashi et al. [22] found that half of the label was excreted from the chicken within 4 to 5 h. Because this was an untested feeding protocol, it initially was evaluated daily, and adjustments were made weekly for the first 4 wk. The physical appearance and activity of the birds on the HE and LE diets were observed to be inferior to those of the COM-fed birds during wk 1, so their ration was doubled in wk 2 (Table 1). Their BW and egg production did not fall as expected at the higher level of intake during the second
week, so the level was reduced back to the original amount during the third week. The amount of ration fed was increased 25% for all 3 treatments during the fourth week. The significantly reduced level of feed consumed by the COM treatment during the second week was apparently due to an unexplained feeding error. The usual compensatory spike in feed intake after returning to full feed occurred during wk 5 but returned to more normal levels during wk 6 through 12. Significant strain differences in feed intake occurred during the 8 wk of postmolt production. Hy-Line W-36 birds consumed a mean of 109 g/bird per day compared with 129, 130, and 135 g/bird per day for Lohmann, Bovans, and HyLine W-98 hens, respectively (P < 0.05). The lower level of intake for the W-36 birds was consistent for all 8 wk. This may be 1 reason the breeder management guide for the Hy-Line W-36 [15] calls for higher nutrient levels in their diet than was used in this trial. BW The BW of the birds in the 3 treatments through the first 3 wk were related to their beginning values (Table 2). The birds in the HE and LE treatments lost less weight than the COM birds during wk 1 and 2. They lost almost no weight during wk 2 due to the extra feed provided. The rate of weight loss increased in wk 3 to about 1.5 times the rate during wk 1 and 2 when only the original amount of feed (≈36 g/ bird per day) was provided to the birds. The birds in the LE and COM treatments consistently lost more weight than the HE birds during the first 4 wk, with the LE treatment birds eventually losing 33.2% compared with 30.2 and 28.1% for the COM and HE, respectively. This was similar to the BW loss reported by Ruszler [23]
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528 Table 2. Body weight (g) and BW change (%) for strain and treatment Week1 Treatment2
Initial
1
2 a
1,770
LE
1,752
COM
1,740
Strain Bovans
1,697b
W-983
1,925a
Lohmann
1,737b
W-363
1,658b
4 a
a
5
12
1,488 –15.9 1,433a –18.2 1,368b –21.4
1,468 –17.1 1,421a –18.9 1,308b –24.8
1,334 –24.6 1,265ab –27.8 1,230b –29.3
1,273 –28.1 1,171b –33.2 1,208b –30.6
1,514 –14.5 1,485 –15.2 1,498 –13.9
1,869 +5.6 1,859 +6.1 1,804 +3.7
1,328b –21.7 1,555a –19.2 1,407b –19.0 1,389b –16.2
1,309b –22.9 1,519a –21.1 1,367b –21.3 1,365b –17.7
1,175c –30.8 1,369a –28.9 1,239bc –28.7 1,283b –22.6
1,141c –32.8 1,291a –32.9 1,171bc –32.6 1,235ab –25.5
1,401b –17.4 1,625a –15.6 1,494b –14.0 1,439b –13.2
1,750b +3.1 2,014a +4.6 1,805b +3.9 1,768b +6.6
Body weight means with different superscripts in columns differ significantly (P < 0.001). Upper number is BW presented in grams. Lower italicized number is percentage of change from initial BW (resented for comparison only; not analyzed). 2 HE = high energy, 9.7% CP, 1,430 kcal/kg; LE = low energy, 9.7% CP, 1,100 kcal/kg; COM = commercial, 14% CP, 2,750 kcal/kg. 3 Hy-Line strains. a–c 1
but was considerably (40 to 45%) more than Ruszler et al. [9] or Ruszler and Novak [10] reported. Each treatment regained BW at a similar rate, with the COM treatment gaining the least numerically. The 4 strains followed the same loss pattern for BW as the treatments. The Hy-Line W-98 strain remained significantly heavier than the others. The Hy-Line W-36 strain experienced the lower rate of BW loss but regained the greater amount on a percentage basis (Table 2).
Egg Production The generally accepted periods of no (<3%) egg production ranged from 7 to 21 d in length, beginning in the second week of molt. Postmolt production performance was numerically less than or equal to molts using periods of feed withdrawal. Actual zero production was not achieved until wk 5 for both treatments and strains except for the LE treatment in wk 4 (Table 3). The extra amount of feed given during
Table 3. Percentage weekly hen-day production for treatments and strains Week 1
Treatment
1
2
3
4
5
6
7
8
HE LE COM Strain Bovans W-982 Lohmann W-362
48 48 49
3.3 3.9 3.5
3.1 1.8 0.5
0.8 0.0 0.8
0 0 0
7.5 3.5 5.3
43.1 43.7 50.4
68.4b 80.3a 75.8ab
43 50 48 51
4.7 3.3 2.7 3.9
2.1 1.8 2.5 0.9
0.5 0.9 0.3 0.3
0 0 0 0
10.5a 7.1ab 3.5b 2.4b
52.9a 57.7a 53.8a 21.7b
86.2a 81.0a 83.8a 53.3b
9
10
11
12
80.6 85.5 85.8
88.1 89.3 90.4
88.5 89.2 91.5
90.6 90.0 92.0
93.1a 85.4b 88.4ab 72.6c
92.6 89.6 90.2 86.0
92.4 88.7 92.4 86.6
92.4 88.4 93.8 89.6
Means with different superscripts in columns differ significantly (P < 0.001). HE = high energy, 9.7% CP, 1,430 kcal/kg; LE = low energy, 9.7% CP, 1,100 kcal/kg; COM = commercial, 14% CP, 2,750 kcal/kg. 2 Hy-Line strains. a–c 1
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HE
3 a
RUSZLER AND NOVAK: ALTERNATE A.M. AND P.M. MOLT FEEDING Table 4. Cumulative eggs per hen housed for treatments and strains Week 1 to 5
1 to 9
1 to 12
HE LE COM Strain Bovans W-982 Lohmann W-362
3.8 3.9 3.7
17.5 18.5 18.6
35.9 36.9 37.2
3.6 3.9 3.8 3.9
20.1a 20.1a 19.1a 14.4b
38.2a 38.8a 37.6a 32.8b
a,b
Means with different superscripts in columns differ significantly (P < 0.001). 1 HE = high energy, 9.7% CP, 1,430 kcal/kg; LE = low energy, 9.7% CP, 1,100 kcal/kg; COM = commercial, 14% CP, 2,750 kcal/kg. 2 Hy-Line strains.
wk 2 appears to be the reason that egg production did not drop below 1% during wk 3, except for the COM-fed birds and the Hy-Line W-36 strain. This shows that the equivalent of zero production (<3%) can be achieved with this feeding protocol. It is necessary for production to drop to this level to insure a uniform molt over the entire flock and to allow enough time of rest from production for the ovarian and oviductal tissues to rejuvenate properly [11, 23, 24]. Egg production would have probably dropped below
1% during wk 3 if the amount of feed had not been increased during wk 2 for the HE- and LEfed birds. None of the treatments showed significant differences in the rate of return to peak hen-day egg production after the molt. It is not certain that peak production by treatments was attained at 12 wk, because the trial had to be terminated at that time. However, this would appear to be true, because these hens peaked at 94 to 96% during the first lay cycle. The Hy-Line W-36 strain returned to production at a significantly slower rate than the other 3 strains until wk 10. This reflects the lower feed intake by the HyLine W-36, which did not satisfy their higher nutrient density requirements. There were no significant differences in the cumulative number of eggs produced on a hen-housed basis except between the W-36 strain and the other 3 strains (Table 4). This difference was consistent during the whole trial. There was not a strain by treatment interaction for egg production during this trial. Mortality Mortality was not an important factor in this study. Three birds died in the first 3 wk, 1 each from Bovans HE, Lohmann LE, and Lohmann COM treatments.
CONCLUSIONS AND APPLICATIONS 1. Daily feeding hens at alternating a.m./p.m. time blocks will induce a complete molt. 2. Zero egg production was attained in all hens, allowing more uniform tissue rejuvenation during the rest period. 3. Molting diets containing 9.7% CP with 1,100 or 1,430 kcal/kg of energy are similar in inducing a successful molt. 4. The energy needs of the flock should dictate the energy level used. 5. Alternating time block feeding could be the method of choice for molting a flock producing at a level near 80% or more to comply with feeding a molt diet each day. 6. The Hy-Line W-36 strain may have performed better if fed a layer diet with nutrient levels recommended in the breeder management guide. 7. The technique is worthy of a full-scale study. Such a study may need to compare the amount fed in each molt feeding period to be equivalent to that amount consumed before initiation of the molt during a 5-h period and 6-h period vs. a 4-h period. A more median nutrient level diet such as 11.85% CP, 1,925 kcal/kg, in addition to the diets used in this study, may offer a better insight of the nutrient levels needed.
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REFERENCES AND NOTES 1. Mrosovsky, N., and D. F. Sherry. 1980. Animal anorexias. Science 207:837–842. 2. American Veterinary Medical Association. 2002. Animal practices guideline – Poultry. Page 77 in AVMA Membership Directory and Resource Manual. Am. Vet. Med. Assoc., Schaumburg, IL. 3. United Egg Producers. 2002. Molting. Pages 8–9 in Animal Husbandry Guidelines. United Egg Prod., Alpharetta, GA.
5. Minear, L. R. 1999. Southern States Research, Richmond, VA. Personal communication. 6. Biggs, P. E., M. W. Douglas, K. W. Koelkebeck, and C. M. Parsons. 2003. Evaluation of nonfeed removal methods for molting programs. Poult. Sci. 82:749–753. 7. Biggs, P. E., M. E. Persia, K. W. Koelkebeck, and C. M. Parsons. 2004. Further evaluation of nonfeed removal methods for molting programs. Poult. Sci. 83:745–752. 8. Ruszler, P. L., C. F. Honaker, L. R. Minear, and C. L. Novak. 2004. Comparison of four commercial molt programs with and without feed restriction procedures. Page 15 in Abstracts. South. Poult. Sci. Soc., USPEA, Atlanta, GA. 9. Ruszler, P. L., C. F. Honaker, and C. L. Novak. 2004. The comparison of two full fed molt programs with two commercial restricted fed molt programs. Page 15 in Abstracts. South. Poult. Sci. Soc., USPEA, Atlanta, GA. 10. Ruszler, P. L., and C. L. Novak. 2005. Determining protein and energy levels needed for full fed molting procedures. Poult. Sci. 84(Suppl. 1):80. (Abstr.) 11. Anderson, K. E., and D. R Jones. Review on the Theological, Philosophical and Physiological effects of fasting across species. Calif. Egg Comm., Upland, CA. 12. Bovans. 1991. Bovans White Management Guide. Centurion Poult. Inc., Bogart, GA. 13. Lohmann North American Edition. 2002. Lohmann LSLLITE Layer Management Guide. Lohmann Tierzucht Inc., Sycamore, IL.
15. Hy-Line International. 2000. Hy-Line Variety W-36 Commercial Management Guide 2000–2001. Hy-Line Int., West Des Moines, IA. 16. SAS Institute. 2001. SAS User’s Guide: Statistics. Version 8 ed. SAS Inst. Inc., Cary, NC. 17. Duncan, D. B. 1955. Multiple range and multiple F-tests. Biometrics 11:1–42. 18. Brake, J. T., and J. B. Carey. 1983. Induced molting of commercial layers. North Carolina Agricultural Extension Service Poultry Science and Technical Guide No. 10. N. C. Agric. Ext. Serv., Raleigh, NC. 19. Ruszler, P. L. 1984. The keys to successful force molting. Virginia Cooperative Extension Service Publ. 408-026 (rev.), Blacksburg, VA. 20. Ruszler, P. L. 1996. The keys to successful induced molting of Leghorn-type hens. Virginia Cooperative Extension Service Publ. 408-026 (revised). Blacksburg, VA. 21. Denbow, D. M. 2000. Gastrointestinal anatomy and physiology. Page 313 in Sturkie’s Avian Physiology. 5th ed. G. Causey Whittow, ed. Acad. Press, New York, NY. 22. Imabayashi, K., M. Kametaka, and T. Hatano. 1956. Studies on digestion in the domestic fowl. Tokyo J. Agric. Res. 2:99. 23. Ruszler, P. L. 1986. Comparison of certain methods for induced molting of layers. Pages 17–33 in Proc. Maryland Nutr. Conf., Baltimore, MD. Univ. Maryland, College Park. 24. Brake, J. T. 1993. Recent advances in induced molting. Poult. Sci. 72:929–931.
Acknowledgments We thank Christa Honaker for her statistical and technical assistance and Brenda Caldwell for technical assistance.
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4. Ruszler, P. L., and L. R. Minear. 1997. Comparison of induced molts using periods of four vs. ten days feed withdrawal. Poult. Sci. 76(Suppl. 1):104. (Abstr.)
14. Hy-Line International. 2001. Hy-Line Variety W-98 Commercial Management Guide 2001–2003. Hy-Line Int., West Des Moines, IA.