effects of increased light and added methionine on molted hens

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Auburn University, Department of Poultry Science, 236 ADS,. Auburn University, AL 36849. Phone: (334) 844-2622. FAX: (334) 8442641. E-mail: ahmadha ...
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EFFECTS OF INCRIZASED LIGHT AND ADDED METHIONINE ON MOLTED HENS' HAFIZ ANWAR AHMAD2, DAVID A. ROLAND, SR., and M. M. BRYANT Auburn University, Department of Poultry Science, 236 ADS, Auburn University, AL 36849 Phone: (334) 844-2622 FAX: (334) 8442641 E-mail: ahmadha @mail.auburn.edu JACK SELF Cal-Maine Foods, Jackson, MS 39207

Primary Audience: Egg Producers, Nutritionists, Researchers, Poultry

Extension Specialists

amino acids during molt affect the progress DESCRIPTION OF PROBLEM of feather replacement [2]. However, the Induced molting is widely used in the commercial layer industry to extend the hen's reproductive lie. Feed deprivation remains the most common method of molt induction due to its efticacy [l, 21. This response is logical because during the annual molt wild birds exhibit anorexia [3] and lose body weight. Feathers have been shown to be protein based, with sulfur-containing amino acids a major component. Research suggests that availability of crude protein and specific

quantity of TSAA and protein fed during the period immediately following feed withdrawal and prior to the onset of egg production varies among programs. 'P.vo of the most frequently used molt programs involve feeding a corn-soy molt diet containing 16% crude protein supplemented with methionine [4] or a lowprotein corn-based molt diet containing 8 to 9% crude protein with no added methionine [5]. Recent research indicates that 16% crude

1 Alabama Agricultural Experiment Journal Series No.

(Abs). 2 To whom correspondence should be addressed

12-965190; Poultry Sci. 73(Suppl. 1):105

LIGHT, METHIONINE, AND MOLTING

374 protein is higher than necessary to obtain optimum postmolt performance [6,7]. One other common molt procedure is to increase the photoperiod to 24 hr for 7 days prior to molt [8]. However, no studies have directly compared increasing the photoperiod to 24 hr for 7 days prior to molt with no increase in photoperiod. Apparently, many producers use increased light and methionine because of the known relationship of light to initiation and cessation of egg production, and the relationship of protein (methionine) to feather growth [2]. Since additional light and methionine are expensive and there is evidence that extended light reduces shell quality [9], the effects of the additional light and methionine commonly used in molt programs should be studied. Because many hens are molted using additional light and methionine, these experiments were conducted to further investigate the effect of additional light and methionine supplementation on the reproductive performance of hens.

supplied at 45 g/hen/day in order to control feed intake and prevent overeating. The molt feed was provided ad libitum during the following 12 days. On Day 21 of the experiment the photoperiod was increased to 13 hr. The photoperiod was increased by 15 min/wk until it reached 17 hr. The hens were fed the molt feed until they reached approximately 5% production (Days 15 to 28). At that time (Week l), all hens were fed a layer feed (Table 1) for the next 6 wk. House temperature was 28.8"C (21.1"C at night) prior to molt. Environmental temperature was increased to 29.4"C (23.8"C at night) on the 1st day of molting, and further increased to 32.2"C (day and night) on the 2nd day to avoid chill stress. On the 16th day of the experiment, 1 day after hens started receiving the molt feed, the temperature was reduced to 29.4"C in the daytime and 233°C at night. Three days after the molt feed was fed (18th day of the experiment) the temperature was further reduced to 26.7"C in the daytime and 21.1" at night. Response criteria used in the two experiments were egg production, feed consumption, egg weight, egg specific gravity, percentage body-checked eggs, and mortality. Egg production, feed consumption, egg weight, and egg specific gravity were determined weekly for 6 wk. Egg weight and egg specific gravity were determined on all the eggs laid on 2 separate days for this purpose. The data were statistically analyzed [lo] using GLM procedure of SAS Institute [ll]. This experiment was conducted in accordance with the guidelines of Auburn University for the care and use of agricultural animals in agricultural research and teaching.

MATERIALS AND METHODS Tho experiments were conducted using 113- and 161-wk-old Hy-Line W-36 hens. Within each experiment 960 hens were randomly divided into six treatment groups of 160 hens each. Each treatment group in both experiments included eight blocks of five cages (four hens per cage). The hens were housed in a computerized control building using two-tiered battery cages. Half of the hens in each experiment continued to receive a 17 hr photoperiod. For the other half, the photoperiod was increased to 24 hr for 7 days prior to molt. Within each light group the hens received one of three molt feeds containing 0.73% (control), 0.60% (low), or 0.80% (high) TSAA (Table 1). The diets' protein levels were 15.90, 15.90, and 17.50%, respectively. MOLT PROCEDURE Seven days prior to feed deprivation 50 hens from each group were weighed. On Day 0 (1st day of feed deprivation, and of the experiment), feed was removed and light was reduced to 12 hr. After 14 days without feed, body weight losses for third- and fourth-cycle hens were 28 and 29%, respectively. On the 15th day, molt feed (Table 1, feed offered immediately after molting period) was provided to all treatments. For the first 2 days, feed was

RESULTS AND DISCUSSION EXPERIMENT 1(THIRD-CYCLE HENS) Increasing the photoperiod to 24 hr for 7 days prior to molt and added methionine levels (0.185,0.212, and 0.05%) had no significant influence on average egg production or feed consumption (Tables 2 and 3). Average egg production and feed consumption values were 48% and 91 g/hen/day, respectively, for third-cycle hens. Photoperiod had no significant influence on egg weight; however, dietary treatments influenced egg weight significantly (Table 4). Hens fed the diet containing the lowest added methionine level (0.05%) produced significantlysmaller eggs than those fed

Research Report 375

AHMAD et al. TABLE 1. ingredient and nutrient composition of experimental diets INGREDIENT

MOLT FEED Control

PO!XMOLT FEED

High Methionine

Low Methionine

LayerA

970

Corn

73.11

69.07

73.28

61.53

Soybean oil meal (4870, CP)

20.03

24.08

20.00

25.03

4.12

4.11

4.12

7.21

Calcium carbonate Di-calcium phosphate

1.39

1.37

1.39

1.59

Salt

0.41

0.40

0.40

0.48

Poultry oil

0.25

0.25

0.25

1.47

Vitamin DremixB

0.25

0.25

0.25

0.25

Mineral premix'

0.25

0.25

0.25

-

DL-Methionine

0.19 -

0.21

0.05 -

0.19

Hardshell (pullet size c a c o 3 )

15.90

Protein

2985

ME, kcalkg

-

1750 2946

15.90 2990

2.00 17.31 2816

Calcium

2.00

2.00

2.00

4.00

Total phosphorus

0.56

0.57

056

0.60

Available phosphorus

0.36

0.36

0.36

0.40

Sodium

0.18

0.18

0.18

0.20

Methionine Methionine (TSAA) Lysine Tryptophan

+ Cystine

0.47

0.52

0.34

0.48

0.73

0.80

0.60

0.76

0.80

0.91

0.80

0.92

0.20

0.23

0.20

0.23

diets containing either 0.185 or 0.212% added methionine. Eggshell quality (Weeks 3 and 4) as measured by egg specificgravity was significantly greater for third-cycle hens receiving the 24-hr photoperiod than for those receiving the 17-hr photoperiod (Table 5). Methionine levels had no influence on average egg specificgravity, although the hens fed 0.212% additional methionine (0.80% TSAA) produced significantly poorer-quality eggs during Week 4 of the experiment. The incidence of body-checked eggs was increased five-fold from 5 to 26% within 1 day after the photoperiod was increased from 17 to 24 hr (Table 6). Within 6 days the incidence of bodychecked eggs returned to premolt values. The

total average mortality for hens receiving a 17 hr photoperiod was 2.08% compared to 3.75% for hens receiving a 24-hr photoperiod (Table 7). There were no si&icant interactions found for any of the above-mentioned parameters. In third-cyclemolted hens, increasingthe photoperiod to 24 hr for 7 days prior to molting had no beneficial effects on postmolt performance except that egg specific gravity was significantly improved (Tables 2, 3, 4, and 5). These results are not in agreement with those of Andrews et al. [12], who found increased egg production and feed consumption in hens receiving a 24-hr photoperiod for 7 days prior to molt. This difference could be due to the

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376

VARIABLE Week 1

Week 2

EGG PRODUCTION Week 3 Week 4 Week 5

Week 6

-

X

70Hen Day

a’bMeanswithno common superscripts in a column differ significantly ( P < .OS).

TABLE 3. Influence of supplying 24 hr light for 7 days prior to molt vs. 17 hr light and additional methionine on Dostmolt feed consumrJtion

FEED CONSUMPTION

VARIABLE Week 1

Week 2

Week 3

Week 4

g/Hen/Day THIRD-CYCLE HENS (EXPERIMENT 1)

FOURTH-CYCLE HENS (EXPERIMENT 2)

‘Significantly different (P < .05).

Week 6

-

X

Research Report 377

AHMAD et al.

TABLE 4. Influence of supplying 24 hr light for 7 days prior to molt vs. 17 hr light and additional methionine on post molt egg weight

0.185%

63.1

63.7

65.6

64.9

63.3

65.5

64.3

0.212%

62.7

62.9

64.6

65.0

65.4

65.3

64.3

a,bMeanswith no common superscripts in a column differ significantly (P < .OS).

differencein light periods compared in the two experiments. Andrews et al. compared an 8-hr photoperiod for 28 days beginning 7 days prior to feed deprivation with a 24-hr photoperiod for 7 days prior to feed deprivation followed by a 12-hr photoperiod for the following 21 days. They made no comparison between the normal and increased photoperiods as we did. Increased egg production and feed consumption in hens receiving a 24-hr photoperiod vs. an 8-hr photoperiod [12] was probably due to duration of light stimulation. EXPERIMENT 2 (FOURTH-CYCLE HENS) Increasing light from 17to 24 hr for 7 days before molting and supplementingmethionine in the molt feed had no sigdicant influence on average egg production, feed consumption, egg weight, and egg specific gravity of fourthcycle molted hens through peak production (Weeks 1 to 6 of layer feed; Tables 2, 3, 4, and 5). Egg production during the 2nd and 4th wk, however, was sigdicantly influenced by dietary treatment (Table 2). Hens fed the diet containing 0.185% added methionine

produced more eggs than those fed the diets containing 0.212% methionine or 0.05% methionine (Table 2). The incidence of body-checked eggs increased five times within 1 day after the photoperiod was increased from 17 to 24 hr (Table 6). The incidence of body-checked eggs returned to premolt values within 6 days, The total average mortality for hens receiving the 17-hr photoperiod was 5.0% compared to 6.67% for hens receiving the 24-hr photoperiod (Table 7). There were no interactions between photoperiod and methionine treatments for any of the performance criteria measured. Increased photoperiod had no effect on the performance of fourth-cycle molted hens (Tables 2, 3, 4, and 5). These results do not agree with those of Andrews et al. [12]. We propose the same explanation as that presented for the third-cycle hens. Increasing synthetic methionine in the molt feed from 0.05 to 0.185 or 0.212% significantly increased egg weight in third-cycle hens. There was no difference in egg weight between the two higher levels of methionine. These results are in agreement with those of

JAPR LIGHT, METHIONINE, AND MOLTING

378

TABLE 5. Influence of supplying 24 hr light for 7 days prior to molt vs. 17 hr light and additional methionine on

EGG SPECIFIC GRAVITY

VARIABLE Week 1

Week 2

Week 3

Week 4

Week 6

-X

FOURTH-CY( LE HENS (EXPERIMENT 2) Photoperiod 17 hr

1.0722

1.0738

1.0743

1.0775

1.0763

1.0748

24 hr

1.0709

1.0738

1.0739

1.0780

1.0762

1.0746

0.05%

1.0708

1.0745

1.0746

1.0778

1.0765

1.0749

0.18570

1.0716

1.0737

1.0736

1.0774

1.0757

1.0744

0.212%

1.0722

1.0732

1.0741

1.0740

1.0781

1.0748

Methionine

a,bMeanswith no common superscripts differ significantly (P sl .OS). 'Significantly different (P < .OS).

BODY-CHECKED EGGS, 70

VARIABLE

17-HrA Photoperiod

24-Hr Photoperiod Day 1

Day 2

Day 5

Day 6

11.8

29.0

23.2

8.5

7.1

Evening'

0.9

23.3

17.5

8.4

10.4

AverageD

5.0cde

26.0a

NOb

8.3*e

MorningB

9.3Cde

12.3

27.9

27.9

12.5

5.8

Evening'

0.5

26.1

2.5.2

11.4

10.5

AverageD

4.gde

26.9ab

2.5.7

11.8'

MorningB

8.6cd

Research Report 379

AHMAD et al. Koelkebeck et al. [7], who reported increased egg weight with methionine supplementation in a 16% protein diet in winter experiments but not in summer or fall experiments. This seasonalresponse could be due to the environmental temperature and related feed intake levels. None of the other postmolt performance variables were different. These results are also in agreement with those of Roland [9], who reported an increase in the incidence of body-checked eggs from 7.7 to 18.3% when the light was increased from 16 to 19 hr. Methionine supplementation had no effect on performance of fourth-cycle molted hens (Tables 2, 3,4, and 5). These results are in agreement with two of the experiments conducted by Koelkebeck et al. [qin summer and fall but not in spring, when they found no effects of methionine supplementation on

the postmolt performance of 65- or 96-wk-old molted hens. Again, this seasonal response could be related to environmental temperature and feed intake. Additional light and methionine supplementation had no beneficial effects on egg production, feed consumption, or egg weight (except in third-cycle hens), but did increase feed cost, utility cost, and the incidence of body-checked eggs in third- and fourth-cycle hens. This increase in cost and lack of corresponding benefits leads us to question the common practice of supplying 24 hr light for 7 days prior to molt and using a molt feed containing more than 0.60% TSAA or 15.90% protein as opposed to reducing the photoperiod from approximately 17 to 12 hr during molt.

17 HR

24 HR

Fasting (2 wk)

0.63

1.25

Molt feed with added methionine (2 wk)

0.63

0.42

Layer feed (6 wk)

0.85

2.11

Total

2.08

3.7SA

Fasting (2 wk)

2.50

2.08

Molt feed with added methionine (2 wk)

1.50

2.55

Layer feed (6 wk)

1.09

2.18

Total

5 .oo

6.67B

MORTALITY

CONCLUSIONS AND APPLICATIONS 1. Incidence of body-checked eggs increased from 5 to 26% in both experiments within 24 hr

after the photoperiod was increased from 17 to 24 hr. 2. Additional light or methionine in molt feed had no subsequent effects on feed consumption or egg production in third-cycle and fourth-cycle hens. It did not affect egg weight or egg specific gravity in fourth-cycle hens. 3. Additional methionine significantly increased egg weight for third-cycle hens only. Depending on price spread between large, extra large, and jumbo eggs, the increase in egg weight could have little or no economic value.

JAPR LIGHT, METHIONINE, AND MOLTING

380

4. Additional light si&icantly increased egg specific gravity for third-cycle hens only. 5 . Additional light and methionine supplementationhad no beneficial effects on egg production or feed consumption; however, they increased feed cast, utility cost, and incidence of body-checked eggs in third- and fourth-cycle molted hens. The common practice of supplying 24 hr light for 7 days prior to molt and using a molt feed containing more than 0.60% TSAA or 15.90% protein therefore seems less efficient than reducing the photoperiod from approximately 17 hr to 12 hr during molt.

REFERENCES AND NOTES 1. Harms, RH., 1983. The relationship of molted primaries of commercial layers to first eggs after molt. Poultry Sci. 62:1123-1124. 2. Brake, J.T., 1992. Mechanisms and metabolic requirements for complete and rapid reproductive rejuvenation during an induced molt - A brief survey. Ornis Scand. 23335-339. 3. Mrosovsky, N. and D.F. Sherry, 1980. Animal anorexias. Science 207837442. 4. Brake, J.T., P. Thaxlon, J.D. Garlich, and D.H. Shemood, 1979. Comparison of fortified ground corn and pullet grower feeding regimes during a forced molt on subsequent layer performance. Poultry Sci. 58:785-790. 5. Swanson, M.H. and D.D. Bell, 1974. Force molting of chickens. 11. Methods. Univ. of California Leaflet 2650, University of California, Davis, CA. 6. Hoyle, C.M. and J.D. Garlich, 1987. Post fasting dietaIy protein requirements of induced-molted hens. Poultrj Sci. 661973-1979. 7. Koelkebeck, K.W., C.M. Parsons, RW. Leeper, and J. Moshtaghian, 1991. Effect of protein and methionine

levels in molt diets on postmolt performance of laying hens. Poultry Sci. 70:2063-2073. 8. Brake, J. and J.B. Carey, 1983. Induced molting of commercial layers. North Carolina A Ext. Sew. Poultry Sci. and Technique Guide No. 10. &Ah Carolina State Univ., Raleigh, NC. 9. Roland, D.k, Sr., 1984. Eggshell quality. I. The body-checked egg. World’s Poultry Sci. J. 40250-254. 10. Statistical procedure. In both experiments data were statistically analyzed as a 2 X 3 factorial with two light schedules and three methionine levels as main factors, using a com letely randomized block design. Means were further difgrentiated by Duncan’s multiple range test using GLM procedure of SAS Institute.

11. SAS Instilute, 1993. SAS User’s Guide: SAS/STAT. Version 6 Edition. SAS Institute, Inc., Cary, NC. 12. Andrews, D.K., W.D. Berry, and J. Brake, 1987. Effect of lighting program and nutrition on reproductive performance of molted SCWL hens. PoultIy Sci. 6612981305.