The Use of Lysine Imbalanced Feeds for Starting or Growing Chicks

RESERPINE AND QUAIL REPRODUCTION Effect of reserpine on pituitary-gonadal axis. Proc. Soc. Exp. Biol. Med. 105: 201-204. Rudolph, J. W., J. C. Gilbreath and R. D. Morrison, 1962. The effect of reserpine on the reproductive

1319

performance of turkeys. Poultry Sci. 44: 184-187. Snedecor, G. W., and W. G. Cochran, 1956. Statistical Methods. The Iowa State College Press, Ames.

The Use of Lysine Imbalanced Feeds for Starting or Growing Chicks D. H. SHERWOOD1, C. D. CASKEY 2 , J. E. JONES 3 , S. B. SMITH4, M. C. VAN WORMER 6 AND J. B. EATON 6 Cooperative Research, Talmo, Georgia 30575 (Received for publication February 8, 1969)

T HAS become a common commercial practice to use some method of delaying the maturity of meat type replacement pullets. Schneider et al. (1955) and Milby and Sherwood (1956) reported that controlling feed intake during the growing period changed the pattern of egg production more than total egg production, in the subsequent laying period. Sherwood (1960) reported that while a high fiber growing feed had been proposed for growing replacements the cost of such a program was quite expensive. Singsen et al. (1964) suggested the use of a lysine deficient feed during the starting period as a means of delaying maturity. Couch et al. (1967) reported that a lysine deficiency in the growing period resulted in improved laying house performance as compared to full feedihg a conventional feed. Peacock (1967) reported that the use of an imbalanced protein feed during the growing period as compared to a conventional program, Had little effect on subsequent egg 1

Cooperative Research, Talmo, Georgia 30575. Cooperative Mills Division, Southern States Cooperative, Inc., Baltimore, Maryland 21203. 3 Clemspn, University, Clemson, South Carolina 2 9 6 $ . 4 Agwiy, Inc., Buffalo, New York 14240. 6 Lanarnark, Columbus, Ohio 43216. 6 Maritime Coop. Service, Moncton, New Brunswick, Canada. 2

production. Slinger and Pepper (1964) suggested severely debeaking the birds at 8 weeks of age. In commercial practice probably the majority of all birds being raised as meat type replacements are raised on a restricted feeding program. EXPERIMENTAL PROCEDURE

The studies reported in this paper were for the purpose of comparing lysine imbalanced feeds during the starter or grower period with conventional feeds fed on both a full feed and controlled intake basis. The studies involved both meat and egg type birds. The trials were conducted at two research farms operated by the Cooperative Research group. One was located at Garner, N. C. and owned by FCX, Inc., of Raleigh, N. C. The other farm, which has since been discontinued, was located at Hershey, Pa., and was owned by Pennsylvania Farm Bureau, now part of Agway, Inc. All birds were vaccinated, following common commercial procedure for Newcastle disease, infectious bronchitis, fowl pox and avian encephalomyelitis. In addition all birds were given Coccivac as an aid in the development of immunity to coccidiosis. The percentage composition of the conventional and low lysine starter and de-

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I

1320

SHERWOOD ET AL. TABLE 1.—Composition of diets

Protein—% Metab. kilocal./kg. Metab. kilocal./lb. Lysine—% Methionine—% Tryptophane—% Calcium—% Available Phosphorus—%

Low lysine starter

Conventional 15% dev.

Low lysine developer

%

%

%

%

5.000 55.613

10.000 17.463 27.000 25.000 3.000 3.000

7.500 69.362

10.000 66.762

— — —

15.000

— —

.500 5.000

—

2.500

— —

—. —

— —

5.000

—

2.000

—

5.000

1.250 1.250 .750 .050 .075 .025 .025 .400 .012 .050 20.3 2,838 1,290 1.08 .34 .29 1.04 .41

—

1.500 5.000 1.000

.500 1.500 28.000

— —

1.000

—

9.750

2.000

—

—

5.000

—• —

1.500 .500 .050 .075 .025 .025 .300 .012 .050 20.5 2,952 1,342 .58 .37 .17 .91 .42

—

.850 1.500 .050 .038

— —

— —

—

—

15.2 3,091 1,405 .67 .27 .17 .82 .35

15.1 3,128 1,422 .42 .31 .13 .96 .35

.500 .050 .038 .250 .050

.250 .050

Each kg. of vitamin mix supplied 2,495,000 I.U. vit. A; 2,495,000 I.C.U. vit. D 3 ; 6.6 mgs. vit. B 12 ; 4.4 gms. riboflavin; 22 gms. niacin; 8.8 gms. d-pantothenic acid; .550 mgs. menadione. Trace mineral mixture contained: 10% manganese; 4 % zinc; 2% iron; 1% copper; 0.3% iodine; 0.05% cobalt; and 24% calcium.

veloper feeds is shown in Table 1. The percentage composition of special low lysine starters used in experiment 7 are shown in Table 2. Where feed was limited the guide plan was as shown in Table 3. Seven trials have been conducted employing starter or grower feeds that were low in lysine, while approximately normal in other amino acids. In six of these trials the birds have been followed through a subsequent laying period. Statistical methods used in all of the trials to be reported were analysis of variance as described by Snedecor(1946). First Experiment. In the first trial, starting April 28, 1964 at Hershey, 1,200 meat

type birds of the Arbor Acre 50 strain were used. In the starter and developer periods there were a total of six pens of 200 birds each. In the subsequent layer period there were 20 pens of 50 birds each. All birds were fed a conventional 20% starter feed on a free choice basis for the first eight weeks. During the grower or developer period one group of three pens was fed the conventional 15% developer on a controlled basis while a second group was fed the low lysine developer. The low lysine developer used in this test differed from that shown in Table 1 by the addition of 10% of a citric acid residue. The nutritive value of this product was not known

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Wheat Shorts Corn Meal Ground Barley Com Gluten Meal (41% protein) Dried Whey Alfalfa Meal (20% protein) Corn Gluten Feed Fat Fish Solubles Distillers Solubles Soybean meal (44% protein) Soybean meal (50% protein) Meat and Bone Scrap (50% protein) Di Calcium Phosphate Ground Limestone Trace mineral mix Vitamin mix Choline Chloride 35% Coccidiostat Plain Salt Santoquin 66 Penicillin—4 gms./lb.

Conventional 20% starter

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L Y S I N E IMBALANCED D I E T S

TABLE 2.—Percentage composition oj feeds used in Experiment 7 Conventional starter

M e t a b . kilocal./kg. M e t a b . kilocal./lb. Protein—% Methionine—% Methionine -{-Cystine—% Lysine—% Tryptophane—% Calcium—% Avail. Phos.—% Lysine/1,000 Cal. Tryptophane/1,000 Cal.

61.83 4.00

17.55 10.00 27.00 25.00

— — — 1.00

— 3.00

2.50 1.00

3.00 5.00

— — 21.25 — —.02 .50

—.05 .10 .10 .15 5.00 2.50 3,056 1,389 20.96 .375 .681 1.109 .258 .944 .438 .798 .186

— 2.00

Low lysine mod. 1

Low lysine mod. 2

59.55 10.00

59.45 10.00

— 14.00 — — 2.00

— 14.00 — — 2.00

1.00

3.00

— — 1.00

53.35 10.00

— 5.00 10.00

— — 1.00

1.00

— 35.38 — — 2.00 —.50

— —

— —

— —

— —

3,056 1,389 18.45 .421 .688 .648 .181 .703 .480 .467 .130

3,153 1,433 14.56 .315 .541 .541 .135 .766 .495 .378 .094

2,968 1,349 16.13 .299 .602 .521 .140 .735 .499 .386 .104

2,900 1,318 20.26 .362 .670 .650 .188 .685 .443 .493 .143

— —

2,944 1,338 20.32 .369 .704 .567 .170 .710 .410 .424 .127

3,060 1,391 18.37 .341 .609 .648 .181 .703 .480 .466 .130

2.00 .05 .10 .10 .20

30.17

— 25.00

1.00

—

1.50 .05 .10 .10 .20

51.17

Low lysine mod. 5

— 43.38 — — — —.50

— • — 10.70 — —.10

— — —.50

Low lysine mod. 4

— — — — — 2.00

1.00

— — 10.70 — — —.30

5.00

Low lysine mod. 3

.30 2.00 .05 .10 .10 .20

1.50 .05 .10 .10 .20

1.50 .05 .10 .10 .20

5.00

— — 10.00

3.00 .10 .50 1.60 .05 .10 .10 .20

b u t it was not thought to have any nutritional value. T h e layer phase of the test started when the birds were 22 weeks old and lasted for 11 months. Second Experiment. T h e second trial, starting in January, 1965 at Garner, involved 3,200 White Leghorn strain cross chicks designated as Duchess 60. Four treatments were used during the starter and developer period as follows: (1) conventional 2 0 % starter then conventional 1 5 % developer with the feed intake controlled starting at 8 weeks, (2) low lysine starter, 8 weeks then developer as Group 1 and full fed, (3) full fed Group 1 diets b u t severely debeak at 8 weeks, as suggested by Slinger and Pepper (1964), (4) full fed Group 1 diets. In the starter and developer period there was a total of 16 pens of 200 birds each and in the subsequent layer period a total of 32 pens of 75 birds each.

1,000 meat type birds of the Arbor Acre 50 strain. During the starter and developer period there were a total of six pens and 20 pens in the layer period. T h e treatments consisted of: (1) conventional feed fed throughout, (2) low lysine starter fed for the first 12 weeks followed by a conventional developer. In this test all birds were full fed at all times.

Third Experiment. T h e third trial, starting in M a y , 1965 at Hershey, involved

Amount indicated was fed every other day except where indicated as daily feeding. On days that mash was not fed 454 grams (1 pound) of cracked corn was fed in the litter for each 100 birds.

TABLE 3.—Controlled feeding plan for pullets Amount/100 birds Table egg birds

Meat type birds

Age kg. 0-6 6-8 8-9 9-10 10-11 11-12 12-13 13-14 14-15 15-16 16-17 17-22

lbs.

Full fed starter feed Full fed developer feed 7.264 16 8.172 18 9.080 20 9.988 22 9.988 22 9.988 22 9.988 22 9.988 22 9.988 22 9.988 22

kg.

lbs.

6.356 (daily) 6.356 6.356 11.804 12.712 12.712 13.620 14.528 15.436 16.344

14 (daily) 14 14 26 28 28 30 32 34 36

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Corn meal Wheat Shorts Ground Barley Corn Gluten M e a l — 4 1 % protein Corn Gluten Feed Dried Whey Alfalfa Meal Fat Peanut Meal—50% protein Dist. Dried Solubles Soybean Meal—50% protein Soybean M e a l — 4 4 % protein Feather Meal Methionine Analogue Limestone Di Calcium Phosphate Trace Mineral Vitamin Mix Choline Chloride—25% Salt M e a t and Bone Scrap—50% protein Fish Meal

Low lysine

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SHERWOOD ET AL.

TABLE 4.—First trial—48 wk.—Limited vs. low-lysine developer Arbor A<;re birds Limited Low 2 -Lysine Growing period % Mortality kg. feed/bird Feed cost/bird—«•

6.0 13.5 91

2.60 18.4 52.0 157 76.6 105 164.4 3.86

2.83 18.6 49.1 149 74.1 96 163.7 4.01

° Differences failed of significance at the 5% level of probability. * Statistically significant at 5% level of probability.

Fourth Experiment. In the fourth trial, starting in July, 1965 at Garner, meat type birds of the Hubbard strain were used. During the starter and developer periods four pens of each of four treatments were used. The four treatments were as follows: (1) low lysine starter first 12 weeks, then conventional developer, (2) conventional starter and developer full fed with birds severely debeaked at 8 weeks, (3) feed with the amount limited, after 8 weeks, to an amount equal to (age in weeks+3)X2, with this amount being fed every day and on alternate days two pounds of oats per 100 birds daily, (4) conventional feed full fed first eight weeks, then limited to an amount about 10% greater than that shown in Table 4. On alternate days grain was fed as for Group 3. Fifth Experiment. In the fifth trial, starting in January 1966 at Garner, 2,400 egg type birds of the Shaver strain were used. During the starting and growing periods four pens of each of four treatments, or a total of 16 pens was used. In the layer period a total of 32 pens were

RESULTS

First Experiment. Results of the first test are shown in Table 4. Birds reared on a limited feed schedule had a lower feed cost (85 cents) to 22 weeks of age than those started on a low lysine feed (91 cents). The birds on the limited program required 11.7 kg. feed per bird to 22 weeks, compared to 13.5 kg. for the low lysine birds. Growing period mortality favored controlled feed at 5.0% vs. 6.0%. Laying house mortality for the two rearing systems was essentially the same at 18.4% vs. 18.6%. Rate of production and hatchability was better for the birds

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Laying period 22 wk. wt.—kg. % Mortality % Production—H.D.° No. eggs—HHA* % Hatchability Chicks/hen housed Age 10% Prod. Feed/doz. eggs-kg.°

5.0 11.7 85

used. The four treatments used were as follows: (1) low lysine starter, (2) modified low lysine with the whey removed, the barley reduced to 22%, the alfalfa to 1%, fat to 2%, the shorts to 9%, the soybean increased to 6% and the corn increased to 30%, (3) conventional feed full fed and (4) conventional feed restricted starting at 8 weeks. Sixth Experiment. In the sixth trial, starting in July, 1966 at Garner, 2,000 meat type birds of the Arbor Acre line 60 strain were used. Sixteen pens were used in the starting and growing period and 32 pens in the breeder period. The four treatments used were: (1) conventional feed, full fed, (2) low lysine starter 1st 8 weeks, then conventional developer, (3) conventional starter with low lysine developer starting at 8 weeks and (4) conventional feed with intake limited. Seventh Experiment. In the seventh test in which birds were not followed through the laying period, broiler type pullet chicks were kept in batteries for 13 weeks and fed various modifications of the low lysine diet. This trial involved 450 birds and was started in March, 1966. Seven diets were used with each diet being fed to four pens of birds. Diets are shown in Table 2.

1323

LYSINE IMBALANCED DIETS TABLE 5.—Second trial, 45 weeks, egg type birds

Grower period % Mortality kg. feed/bird Feed Cost/bird—£ Layer period 20 wk. wt.—kg.** % Mortality 0 % production-hen day** No. eggs/hen house av.° Feed/doz. eggs-kg. Age 25% production-days*

:

Low lysine starter

Conventional feed-full fed severe debeak

Conventional feed-full fed

17.25 5.65 38.5

6.64 6.99 47.6

7.01 7.20 48.5

10.89 7.36 49.3

1.30 20.6 71.3 199.1 1.91 158.8

1.38 23.8 68.2 190.9 2.00 148.9

1.50 25.0 73.2 195.4 1.81 149.1

1.44 21.0 69.9 194.4 1.97 147.1

Failed of significance at 5% level of probability. Statistically significant at 5% level of probability. Statistically significant at 1% level of probability. LSD % production kg./feed/doz. eggs Age 25% production

started on the controlled feeding program so that they averaged 105 chicks per hen housed as compared to 96 for the low lysine treatment. Second Experiment. Results of the second test are shown in Table 5. Birds reared on a limited feed schedule had a lower feed cost (38.5 cents) to 20 weeks of age than those started on a low lysine feed (47.6 cents). The birds on the limited program required 5.65 kg. feed per bird to 20 weeks compared to 6.99 kg. for the low lysine birds. Growing period mortality was low for the low lysine feed at 6.64% vs. 17.25%. Laying house mortality for the two rearing systems was lower for the limited feed at 20.6% compared to 23.8% for the birds on the low lysine feed. Rate of production was better for the limited feed at 199.1 vs. 190.0. Age at 25% production was earlier for the low lysine feed at 148.9 days vs. 158.8 for the limited feed. Debeaked birds had a mortality of 25%, average hen day production of 73.2%, hen housed average of 195.4 eggs and re-

t.05 2.69 .10 7.9

t.01 3.63 .13 10.7

quired 149.1 days to reach 25% production. Feed cost to 20 weeks of age was 48.5 cents. Mortality for the growing period was 7.01% and 7.20 kg. of feed were required to 20 weeks of age. Birds full fed a conventional diet had a higher feed cost to laying house age than any other treatment but were slightly ahead of birds on the low lysine starter in both hen day and hen housed production. Third Experiment. Results of the third test are shown in Table 6. Birds reared on a conventional feed had a higher feed cost (78.5 cents) to 20 weeks of age than those on the low lysine feed (74.8 cents). The birds on the low lysine feed required 10.1 kg. of feed to 20 weeks of age as compared to 11.5 kg. for birds receiving the conventional feed. Growing period mortality was lower for the low lysine feed at 7.4% compared to 9.6% for the conventional feed, which was full fed at all times. Laying house mortality for the two types of feed was lower for the low lysine feed at 22.2% vs. 25.8. Percent production for the low lysine feed was slightly superior to the

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:

Conventional feed-limited

1324

SHERWOOD ET AL.

TABLE 6.—Third trial—39 weeks, Arbor Acre birds Conventional feed full fed Grower period % Mortality kg. feed/bird** Feed cost/bird—£

9.60 11.5 78.5

7.39 10.14 74.8

2.70 25.8 51.0 119.0 3.60

2.46 22.2 52.1 124.2 3.61

182

184

49.8 54.0 58.1

49.6 53.9 57.9

* Statistically significant at 5% level of probability. ** Statistically significant at 1% level of probability.

conventional feed at 5 2 . 1 % vs. 51.0%. N u m b e r of eggs per hen housed average was also better for the low lysine feed at 124.2 vs. 119.0. Egg weights were slightly lower for the low lysine than for the conventional feed. Fourth Experiment. Results of the fourth experiment are shown in Table 7. Birds reared on a limited feed schedule had a lower feed cost (90.93 cents) to 24 weeks of age than those started on a low lysine feed (100.60 cents). T h e birds on the limited feed program required 13.8 kg. feed per bird to 24 weeks compared to 14.7 kg. for the low lysine birds. Growing period mortality was lower for the limited feed at 8.2% vs. 9.6%. Laying house mortality for the two rearing systems was lower for the limited feed at 2 0 . 3 % vs. 29.7%. Percent production was higher for the limited feed at 56.4% compared to 54.1 for the low lysine feed. T h e percent of hatchability was essentially the same with 8 5 . 3 % for the

Laying house mortality for the three schedules was lowest for the limited feeding at 6 . 5 % compared to 9.6% for the low lysine and 13.0 for full feeding. Percent production was essentially the same for the full fed birds at 76.6% and 76.4% for birds fed the low lysine feed, and 74.2% for the limited group. N u m b e r of eggs per hen housed was essentially the same for the limited feed at 211.8 and 211.3 for the low lysine feed. N u m b e r of eggs per hen housed for the full fed birds was 207.1. Age of birds to reach 5 0 % production was 164.8 days for full fed, 166.7 days for the limited birds and 168.1 for the low lysine birds.

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Layer period 20 week wt—kg.* % Mortality % Production—hen day No. eggs/hen housed av. Feed/doz. eggs—kg. Age 50% production— days Egg weights— grams—Nov. Dec. Jan.

Low lysine starter— 1st 12 weeks

limited feed and 8 5 . 5 % for the low lysine feed. Chicks per hen housed were higher for the limited feed at 100.0 vs. 90.0. The debeaked birds had a growing period mortality of 6.6% and 17.2 kg. feed were required per bird to 24 weeks. Laying house mortality was 12.6%. Percent production was 53.9% with 122.1 eggs per H H A . Percent hatchability was 82.6 with 101.0 chicks per hen housed. A fourth group fed on a different limited feeding schedule performed slightly poorer t h a n the control group, b u t better than the low lysine group. Egg weights were lower for the low lysine group than for any other treatment. Fifth Experiment. Results of the fifth experiment are shown in Table 8. In comparing the three feeding schedules the birds reared on the limited feed had a lower feed cost (44 cents) to 20 weeks of age than the low lysine (50.5 cents) or full fed birds (51.2 cents). The birds on the limited feed required 6.5 kg. of feed to 20 weeks compared to 6.86 kg. for the low lysine and 7.59 kg. for the full fed birds. Growing period mortality for the limited feed and low lysine feed was exactly the same a t 6 . 7 % while it was 8.8% for the full fed birds.

1325

L Y S I N E IMBALANCED D I E T S

TABLE 7.—Fourth trial—35 weeks, Hubbard birds Low lysine starter—12 wks. conventional dev.—full fed

Conventional starter and developer severe debeak at 8 weeks

Conventional feed limit start—8 wks.

Conventional feed limit start—8 wks.

9.61 14.7 100.60

6.60 17.2 112.41

8.21 13.8 90.93

13.73 14.2 92.53

3.32 29.7 54.1 105.8 3.19

3.66 12.6 53.9 122.1 3.24

3.20 20.3 56.4 117.1 3.10

3.18 24.0 55.9 113.3 3.10

Grower period % Mortality kg. feed/bird Feed cost/bird—i

—

—

58.0 61.1 61.6 82.6 101

55.7 58.5 59.8 85.5 90

—

57.9 61.0 61.5 85.3 100

—

57.7 61.2 61.7 84.0 95

Differences were not statistically significant at 10% level of probability. Differences statistically significant at 5% level of probability. Statistical methods not applied to other data. L.S.D. hen housed ave — t.05 t.01 10.0 13.5

TABLE 8.—Fifth trial—40 wks., egg type birds Singsen Modified low lysine low lysine full fed—12 wks. full fed—12 wks. Grower period % Mortality kg. feed/bird Feed cost/bird—£ Layer period 21£ wk. wt.—kg. % Mortality** % production—hen day 1 No. eggs/hen housed av. 1 Feed/doz. eggs—kg.1 Age at 10% prod.—days** Age at 50% production—days** Egg wts.—July Aug. Sept. Egg wt.—grams—av.*

Conv. starter full fed— 8 wks.

Conv. starter restricted at 8 wks.

6.66 6.86 50.5

8.11 6.82 47.8

8.77 7.59 51.2

6.66 6.5 44.0

1.70 9.6 76.4 211.3 1.92 155.6 168.1 53.0 51.2 54.2 52.6

1.71 7.6 76.3 214.5 1.92 155.0 168.4 48.8 50.9 53.4 51.2

1.73 13.0 76.6 207.1 1.90 150.8 164.8 49.3 51.1 53.5 51.4

1.71 6.5 74.2 211.8 1.95 154.8 166.7 49.8 51.8 53.7 51.8

1 Differences fail of statistical significance at 10% level of probability. * Differences statistically significant at 5 % level of probability. ** Differences statistically significant at 1% level of probability. L.S.D. t.05 t.01 Mortality 3.8 5.2 Average egg wt. 1.00 1.35 Age at 10% Prod. 2.0 2.6 Age at 50% Prod. 1.7 2.3 Statistical methods not applied to other data

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Layer period 25 wk. wt.—kg.° % Mortality % production/hen day No. eggs/hen housed1 av.* Feed/doz. eggs—kg.'3 Age 50% production Egg weights—gms.—-Feb. Mar. Apr. % Hatchability Chicks/hen housed

1326

SHERWOOD ET AL. TABLE 9.—Sixth Trial—28 weeks, Arbor A ere birds Conventional starter and developer

Grower Period % Mortality kg. feed/bird Feed Cost/bird—f<

7.6 28.2 93

Conventional starter low lysine developer 4.1 33.0 104

Conventional but limited feed

3.3 21.0 64

3 .20 10.2 55.9 102.1 3.10 173.9 177.3 56.2 58.2 59.9 62.4 81.0 71.0

2.84 10.9 57.8 105.1 3.00 177.0 180.0 54.7 56.3 58.9 60.4 85.4 79.0

3.15 10.0 58.1 101.9 3.07 175.1 178.0 56.1 58.4 60.1 62.1 81.3 71.0

2.15 6.9 60.4 111.8 2.80 179.8 181.5 54.6 56.3 58.0 60.5 88.1 88.0

5.24

4.80

5.19

4.12

* Differences statistically different at 5% level of probability. ** Differences statistically different at 1% level of probability. L.S.D. t.05 Age 10% Prod.—days 1.40 Age 25% Prod.—days 1.04 Cumulative egg wts.—grams .92 Hen housed production 3.42 Statistical methods not applied to other

In this trial birds on one low lysine starter feed had the largest size of the four groups while birds on the other low lysine feed had the smallest egg size. Sixth Experiment. Results of the 6th trial are shown in Table 9. Birds reared on a limited feed schedule had a lower feed cost (64 cents) to 22 weeks, 5 days of age than those of the full fed (106 cents) or low lysine birds (93 cents). Birds on a low lysine developer had a feed cost of $1.04. The birds on the limited feed required 21.0 kg. of feed to 22 weeks, 5 days compared to 28.19 for the group receiving the low lysine diet and 33.41 for the full fed group. Growing period mortality was lower for the limited feed at 3.30% compared to 5.55% for full fed birds and 7.61% for the low lysine birds.

t.01 1.90 1.41 1.24 4.61 data.

Laying house mortality was lowest for the group limited during the growing period at 6.9%. Mortality was essentially the same for the other three groups ranging from 10.0% to 10.9%. Rate of production and hatchability was higher for the limited group so that they produced 88 chicks per hen housed in the short laying period, compared to 71 for full fed birds and those on a low lysine developer and 79 for those on a low lysine starter. Egg weights were higher for full fed birds and those on a low lysine developer. Seventh Experiment. As mentioned the seventh test involved female broiler type chicks maintained in batteries. Results of the test are shown in Table 10. Birds on the low lysine feed as suggested by Singsen et al. (1964) weighed 1.83 kg. as compared to 2.30 kg. for those on a conven-

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Layer Period 24 wk. weight—kg.**» % Mortality % Production—hen day No. eggs/hen—HHA* Feed/doz. eggs—kg. Age at 10% Prod.—days** Age at 50% Prod.—days** Egg wts.—grams—Feb. Mar. Apr. May* % Hatchability Chicks/hen housed Feed/doz. eggs incl. grower period kg.

5.6 33.4 106

Low lysine starter and conventional developer

1327

LYSINE IMBALANCED DIETS TABLE

1 0 . --Effect

13 Wk., 1 day data Mortality—% Body wt.—kg. Kg. feed/kg. of weight

of modifications of low lysine diet on performance to 13 weeks1

Conv. starter

Low lysine

Low lysine mod. 1

Low lysine mod. 2

Low lysine mod. 3

Low lysine mod. 4

Low lysine mod. 5

6.3 2.30 4.16

1.6 1.83 2.97

1.6 2.23 3.64

3.1 2.15 3.84

3.1 1.44 2.63

3.1 1.30 2.38

1.6 2.15 4.47

Broiler cross chicks—females only.

DISCUSSION Limiting feed during the growing period results in a lower cost to maturity or to a given rate of egg production than a low or lysine imbalanced starter or developer feed. In most tests feeding a conventional feed on a full fed basis has been more expensive than the low lysine approach but not in all trials. In most, but not all trials, limiting the feed has resulted in greater delay in sexual maturity than the low ly-

sine approach. Limiting the feed during the growing period has resulted in lower hen house mortality and better production, on a hen housed basis and in most cases on a hen day basis as well. Hatchability is also normally better for birds on a limited intake basis. In all trials where there has been a comparison on the low lysine feed with birds full fed a conventional feed results have been as good as or better from the low lysine feed than from full feeding a conventional feed. Egg size has been essentially the same for birds on the low lysine feed as compared to limited feed intake while in most trials egg size has been somewhat heavier for birds full fed the conventional feed. The lysine requirement during the developer period from 8 weeks to maturity does not exceed .30% lysine/1,000 metabolizable kilocalories. With the low lysine starter feed the tryptophane level is important as is the lysine level and it is suggested that the amount of tryptophane be about .13%/1,000 metabolizable kilocalories and the lysine in the low lysine starter about .42%/1,000 metabolizable kilocalories. The values are based on the University of Maryland expectancies as revised in 1967. SUMMARY Limiting feed of replacements chickens during the growing period results in lower feed cost to maturity than feeding a lysine imbalanced feed in either the starting or growing periods. Laying house perfor-

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tional feed. Birds on modifications 1, 2, and 5 were definitely heavier than birds on the Singsen diet at 2.23, 2.15 and 2.15 kg. respectively. These diets were all higher in lysine than the Singsen diet, and apparently were too high to have a pronounced growth depressing effect. Birds on modifications 3 and 4 grew at a markedly slower rate than birds on the Singsen diet. Birds on these two diets had 13 week weights of only 1.44 and 1.30 kg. respectively, and also showed very poor feather development. It would appear that the tryptophane content of modifications 3 and 4 was too low. These diets were lower in methionine plus cystine than the Singsen diet modification, but 4 was nearly as high in methionine plus cystine as modification 1 which supported good growth. It was noticeable that birds on the Singsen diet and modifications 3 and 4 billed out more feed than birds on other diets. It would appear that this might be connected with low palatability of diets high in barley or distillers dried solubles.

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ACKNOWLEDGEMENT T h e assistance of Mrs. Radford Murphy in summarizing the data and preparing the manuscript is gratefully acknowledged. REFERENCES Couch, J. R., J. Trammell and C. R. Creger, 1967. Effect of low lysine diets on nutrition and rearing

of broiler breeder replacement pullets. Poultry Sci. 46: 1249. Milby, T. T., and D. H. Sherwood, 1956. The influence of feed intake during the growing period on the subsequent performance of laying hens. Poultry Sci. 35: 863-869. Peacock, R. G., 1967. Delaying the sexual maturity of broiler breeder replacement pullets by the use of imbalanced nutrient diets. Proceedings 1967 Maryland Nutrition Conference for Feed Manufacturers: 67-77. Schneider, A. J., B. B. Bohren and V. L. Anderson, 1955. The effect of restricted feeding on several genetically controlled characters in the fowl. Poultry Sci. 34: 691-702. Sherwood, D. H., 1960. Methods of delaying pullet maturity. Poultry Sci. 39: 1293-1294. Singsen, E. P., J. Nagel, S. G. Patrick and L. D. Matterson, 1964. The effect of a lysine deficiency on body weight and age at sexual maturity of meat type pullets. Poultry Sci. 43: 786-787. Slinger, S. J., and W. F. Pepper, 1964. Effects of debeaking and feeding whole grain on the reproductive performance of pullets. Poultry Sci. 43: 356-362. Snedecor, G. W., 1946. Statistical Methods, 4th edition, The Iowa State College Press, Ames, Iowa. University of Maryland, 1967. Relative available nutrient content of feed ingredients. Mimeograph revised 7/9/67.

A Comparison of Phosphorus Assay Techniques with Chicks 5. I N F L U E N C E O F S U P P L E M E N T A L M A G N E S I U M ON P E R F O R M A N C E OF SOFT P H O S P H A T E AND MONOSODIUM PHOSPHATE1 B. L. D A M R O N and

R. H.

HARMS

Florida A gricidtural Experiment Station, Gainesville, Florida 32601 (Received for publication February 11, 1969)

T

H E nutritional interrelationships of calcium, phosphorus and magnesium have long been recognized. Chicco et al. (1967) reported t h a t supplementing a degerminated corn-soybean meal type diet with 2,000 p.p.m. of magnesium im1

Florida Agr. Exp. 3180.

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proved the performance of chicks when the diet was deficient in calcium. However, when the level of calcium was increased to meet the apparent requirement of the chick, this level of magnesium gave a small reduction in body weight and a significant depression of tibia ash. I t is an accepted fact t h a t adverse cal-

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mance of birds on the controlled feed plan during the growing period was superior to those on the lysine imbalanced feed. T h e use of a lysine imbalanced feed during the starting or growing period has been as good as or better than full feeding a conventional feed, from the standpoint of subsequent laying house performance. I n most trials hatchability has been better for birds maintained on a controlled feeding program during the growing period than full feeding either a conventional or lysine imbalanced feed. The tryptophane level is important in a lysine imbalanced starter feed.