y lation Bulletin 456 December 195JJ Restricted Feeding of Growing Pullets By RICHARD C. RINGROSE Agricultural Experiment Station University of New Hampshire Durham, New Hampshire » \^W I i » ■ — > tation Bulletin 456 December 1958 Restricted Feeding of Growing Pullets -~-£SS? By RICHARD C. RINGROSE Agricultural Experiment Station University of New Hampshire Durham, New Hampshire Acknowledgements The author wishes to acknowledge the valuable assistance of the following men, former Graduate Research Assistants in the De- partment of Poultry Science, in planning and conducting the re- search reported in this bulletin: Lawrence M. Potter. Richard M. Hatch. William R. Sansalone. Richard M. Vondell. and Willis S. Reed. Cover New Hampshire pullets reared in confinement at twenty weeks of age: left, full fed pullets: right, restricted fed pullets. Restricted Feeding of Growing Pullets By R. C. Ringrose* Introduction POULTRYMEN are still seeking an answer to the question, "Which is the best feeding system for my flock?" Those close to the problem realize that there is no "best" method for poultrymen as a group. Labor and management problems peculiar to a farm often dictate the choice of a feeding system. During the past few years the terms restricted or controlled feeding have been employed to describe a method of feeding pullets grown for flock replacement. The main objective of such a feeding program is to delay sexual maturity and thereby increase initial egg size, which would result finally in the production of a larger number of hatching eggs. Addi- tional advantages claimed are lower cost of rearing a pullet, reduction of adult mortality, and increased egg production. As a result of breeding work aimed at developing strains of chickens which will grow rapidly to broiler age, such strains when reared for replacement pullets mature early and lay eggs of small initial size. It was felt by some poultrymen that if sexual maturity could be delayed, egg size not only would be increased, but more hatching eggs would be produced. Since the program of feeding to delay sexual maturity was a field de- velopment without comparative data, it was decided to obtain experimental data as an aid in evaluation and development of a system of feeding to de- lay sexual maturity. Review of Literature At the time this study was initiated, literature bearing on the subject was nonexistent. During the development of the research, a few reports appeared. Milby and Sherwood (1) reported a comparison of full feeding versus feeding limited to a definite number of hours daily. New Hampshire and White Plymouth Rock stock was reared in confinement. Growth was re- tarded and sexual maturity delayed about two weeks in both breeds by the restricted feeding program. The amount of feed required to rear a pullet to point of lay was virtually the same on both programs for the White Rocks and 1.8 pounds more for the New Hampshires on the re- stricted program. For the laying period there was little difference in egg production, egg weight, body weight, or mortality. Sunde, Cravens, Bird, and Halpin (2) reared White Leghorn pullets by * Dr. Ringrose is Poultry Nutritionist in the New Hampshire Agricultural Experi- ment Station. 3 full feeding in confinement a "complete'' and "incomplete" diet. The in- complete diet contained no animal protein, while the complete diet con- tained 3 percent condensed fish solubles and penicillin. Both diets were sup- plemented with vitamin B12. Pullets fed the complete diet were heavier at 20 weeks of age and reached sexual maturity 10 to 12 days earlier. No effect on egg production, mortality, body weight, or hatchability was found. On any given calendar date egg weights were essentially the same. Appar- ently body weight and sexual maturity can be influenced with very little change in the diet fed. Singsen, Matterson, Kozeff, and Stinson (3) reared Barred Plymouth Rock and New Hampshire pullets to eight to twelve weeks of age on a high efficiency diet. During the growing period, on an excellent mixed grass and clover range, high and low efficiency rations were fed both on a full feed and restricted basis. They state that the rations fed during the grow- ing period had a very marked effect on efficiency of feed utilization and body weight to six months of age. no consistent effect on egg production or mortality, and only a slight effect on the size of eggs laid. Davis and Watts (4) used a starting period of 10 weeks, a growing period to 20 weeks, and a laying period of 9 months. They studied mash- grain ratios of 70-30 and 30-70 and also restricted total feed. They report that starting treatment may affect laying performance but that growing treatment did not, except to delay sexual maturity. It is stated that egg size appears to be due primarily to age and that meat strain birds differ from egg strain birds in their response to different ration treatments. Schneider, Bohren, and Anderson ( 5 ) compared the effects of a ration expected to promote fast growth with a ration expected to allow only slow growth. They found that restriction significantly reduced body weight but that four weeks following full feeding there was no difference in body weight. Sexual maturity was retarded 15 days when measured by average age at first egg, 27 days when measured at 25 percent production, and 14 days when measured at 50 percent production. Since severe feed restric- tion was practiced during a six-week period after some of the restricted grown pullets were in production, it is probable that this treatment was a major factor in delaying the attainment of the 25 percent level of pro- duction. In this research it was found that egg production was not different in the two groups of birds, but that the production pattern differed. The groups grown with feed restriction laid at a faster rate during the latter portion of the production cycle. It was found also that there was no difference in egg weight at any given age. Laying house mortality was lower for the restricted birds than among those fast-grown on a high protein feed (25.15 percent) full feed. Fertility and hatchability did not differ sig- nificantly, although there was a slight and consistent advantage for the slow grown pullets. Milby and Sherwood ( 6 ) reared pullets by full and restricted feeding both in confinement and on range. They restricted the feed from six weeks of age until the beginning of production to 85 percent of the feed con- sumed by the full fed pullets in confinement and 70 percent of the full fed pullets on range. This significantly reduced body weight and increased age at sexual maturity 10 to 15 days. Restricting the feed did not result in any saving in feed cost, primarily because of the longer feeding period required to reach sexual maturity. They found no real effect on egg pro- duction, egg weight on any calendar date, body weight after six weeks of production, fertility, hatchability, or laying house mortality. Progress reports from this station on some of the studies summarized here have been presented (7,8,9). Experimental Throughout the studies to be reported, customary management practices were followed. Starting, growing, and laying feeds were used, the change being made at the usual times. For some experiments commercially mixed branded feeds were used, for other experiments custom mixed New Eng- land College Conference formula feeds were used. Whenever feed restric- tion was practiced, sufficient feeder space was allowed so that all chickens could eat at one time. All feeds used were of the type termed "high efficiency" or "high energy*' at the time the experiment was conducted. Vaccination and immunization for disease control was according to accepted practice for this area at the time. Drug medication, except in one experiment specifically mentioned, was limited to the use of a coccidiostat for coccidiosis control. Artificial light was used to maintain a minimum 14-hour day, regardless of season of year or age of the chickens. This practice was based on re- search at this station demonstrating that chickens hatched in the fall months can be delayed in sexual maturity about two weeks, when grown under conditions of uniform 14-hour light as compared to chickens sub- jected to the conditions of natural daylight (10,11). Since we were in- terested in delaying sexual maturity, it seemed logical to make use of this management practice and determine what delay might be obtained by the feeding program. Culling was not practiced at any time. On occasion it was necessary to adjust pullet numbers to available housing space. This was done by random selection and distribution of the pullets to be used. For determining pullet age at a particular production level, an average of three days' egg production was used to determine the percentage egg production. Average egg size to 50 percent egg production level was meas- ured by weighing all eggs laid to this specific time and dividing by the number of eggs weighed. In order to obtain the egg size distribution throughout an experiment, the usual type of commercially manufactured farm egg grader was used. Up to the point of 50 percent egg production each day's eggs were graded. After the time of 50 percent egg produc- tion, one week's eggs out of every four weeks' production was used (25 percent sample). The number of eggs per hen was figured on a hen-day basis. Since the initial program for restricted feeding was of field origin, the first two experiments (No. 1 and 3) were an attempt to evaluate this pro- gram under controlled conditions. The first experiment was started in November, 1952, utilizing a com- mercial strain of meat-type New Hampshire stock. One hundred and fifty straight run chicks were randomized into each pen with the cockerels re- moved at twelve weeks of age. The feeding treatments were as follows: Full Fed Mash was kept in the hoppers at all times. Starting mash was fed to 12 weeks of age and growing mash from 12 to 20 weeks of age. Restricted For the first two weeks the chicks were full fed. Starting at two weeks of age, the feeding time was gradually reduced (approx. 1 hour per week) until, at seven weeks of age they were limited to four hours of mash feed- ing each morning. Enough mash was placed in the hoppers so that at the end of the four-hour feeding period the hoppers were empty. Starting at two weeks of age the chicks were fed oats, increasing the amount as rap- idly as possible until the oats comprised 25 percent of the total feed. The oats were fed at 4:00 p.m. This system of feeding was continued until the pullets were 20 weeks of age. Starting mash was fed for the first 5 weeks and growing mash from 5 to 20 weeks of age. Sufficient hopper space was provided so that all chickens could eat at the same time. Because of limited laying house facilities, at 16 weeks of age a random sample of 35 pullets was moved to the laying pens. At 20 weeks of age each pen was placed on the same feeding program for the laying period. Th:s program consisted of feeding a 15 percent protein all-mash breeder feed supplemented with a 20 percent protein breeder mash pellet and whole oats. Laying house records were obtained to 52 weeks of age. The data from this experiment is presented in Table 1. Experiment 3 was a repetition of Experiment 1. The only change in the feeding program was that in the restricted feeding system enough mash was placed in the hoppers so that at the end of the four-hour feeding period mash was left in the hoppers. At this time the hoppers were removed from the pens. This procedure was adopted because it made the mechanics of handling the experiment simpler and insured availability of feed for the four-hour period. The experiment was started in October. 1953, with duplicate groups on each feeding program. Meat-type New Hampshire chicks from the same commercial source as used in Experiment 1 were utilized. At the start 122 chicks were randomized into each pen. Cockerels were removed at 10 weeks of age. The data from this experiment is presented also in Table 1. Since the results from Experiments 1 and 3 indicated that feed restric- tion on a time basis was not too successful and at certain periods may result in no feed restriction, attention was turned to feed restriction on a poundage basis. Experiment 4 was designed to compare full feeding with an 80 percent of full feed program utilizing spring-hatched, range-reared stock. The same commercial source of New Hampshire chicks as used in previous experi- ments was utilized. The experiment was started in March, 1954, with duplicate pens for each feed treatment and 112 sexed pullet chicks random- ized into each pen. For the full fed groups the all-mash feeding system was used throughout the rearing period. Starting mash was fed to 6 weeks of age after which growing pellets were fed to 20 weeks of age. The restricted groups were full fed to six weeks of age with starting mash. Small quantities of oats in - = 0 ■e - ■c 'Z T}> V£3 VO CO ON t}< ON *# eg' **' lo ui co' CM i— l CO r— I on r~ O CO CO co' O con i— I l^- -d 03 4-j Lid en " 03 (3 03 03 ft w 3 03 oq ** co i— i eg co co ^ £t eg eg ■* eg " ^ eg eg C3 I-H LO i— i O f~ O no NO LO LO ^ LO' t^ i-H On rt CO On CO O On ^O £ t- On r-i eg rt ^ rH eg egcoi-HcoLOLO^p— ico LONONOLor^or-^i—i i-H On i — ' i — i CO Cfl en vO ( 1 Cd 03 tN „ -O T3 ^ _C .O -O _3 „3 ^ >^3 >^s> c o ■I = £ p o eg C V, *-» . <° h CD 03 IH ft -c -a 03 03 03 03 r LC ei 03 bo O ^^ c ft OJ o OJ LO en en _o £ £ £ cj SR bB 03 O — 3 o LO o 3 _C eg eg o s-l 3 w _2 oj 1 ft o — ^ 03 'en 03 en N — i "^ 03 .2 .Sf o en — '5 LO M b£ 3 £ , . bU bt ft C3 03 03 .-a 1 03 03 03 "*J ^ bD > > tn 3 < < < s Oh it js ^ o CD ** Ph -a 3 >i O -a ca eg o eg 03 — 03 1) ft ft -a -c OJ (U 03 03 3 o "h -3 03 "^ bJQ M 03 b£ C .s | _ as W W J E en bJD bU were fed also to accustom the chicks to the oats. At six weeks of age a change was made to growing pellets, 20 percent feed restriction was started and of the total amount of feed allowed, whole oats made up approximately 25 percent. The pullets were fed on this basis to 20 weeks of age. At eight weeks of age the pullets were moved to range plots of one- quarter acre each. The vegetation was only moderately good and con- tained some ladino clover. From 8 to 20 weeks of age, both treatment groups could eat as they wished of the range vegetation, with the restricted treatment being limited to 80 percent of the feed consumed by the full fed treatment groups. At 20 weeks of age the pullets were moved to laying pens. Feed restric- tion was continued until five percent production was reached, at which time the pullets were placed on full feed. The data from this experiment is presented in Table 2. In view of the results obtained up to this time there was considerable interest in the extent to which pullets might be delayed in egg production. For this reason, in Experiment 6 more severe feed restriction was prac- ticed starting at the early age of two weeks. Experiment 6 was started in November, 1954. and the pullets were grown in confinement. Duplicate pens of 45 sexed pullet chicks from the previ- ously used commercial strain of New Hampshires were used. The chicks were full fed to two weeks of age at which time the treatments of full feed, 80 percent, and 70 percent of full feed were established. All-mash feeds were used throughout the experiment with the starting feed being fed to eight weeks of age after which time a growing feed was used. At 20 weeks of age all groups were fed an all-mash breeder ration. The data from Exoeriment 6 is presented in Table 2. At this period in the development of the research, current comment was to the effect that restricted feeding should be used for rearing all tvpes of chickens, not only meat-type chickens to be used for the production of hatching eggs. For this reason it was decided to conduct experiments using White Leghorn stock. Two experiments were conducted using the same commercial strain of White Leghorn chicks for each experiment. Experiment 7 was started in April, 1955. with duplicate pens of 78 sexed White Leghorn pullet chicks on each feed treatment. The chicks were brooded and full fed to six weeks of age at which time they were moved to range and the treatments of full feeding and restricted feeding were started. The experimental design was developed on the basis that 70 per cent of full feeding would be studied. However, due to an outbreak of Blackhead disease in all experimental groups, it was necessary, for a period of about three weeks, to full feed the restricted groups in order to secure adequate feed and drug intake to control the disease problem. Following control of the disease, restricted feeding again was nracticed at the 70 percent of full feed level. Over-all restriction amounted to 21.3 percent. At 20 weeks of age the pullets were moved to the laving Dens. Feed re- striction continued until 23 weeks of age. at which time the full fed groups were laving their first eggs. At this age feed restriction was terminated and full feeding of both groups was practiced. The all-mash feeding system was used throughout the experiment. Start- ing mash was fed to six weeks, growing pellets while on range, and breeder mash during the laving period. The results from this experiment are presented in Table 3. l/> - v WD !S = 3 0 - a S 0 U - TS — ■ Jii "S v S - 3 - "a - - £ - a Z no c - [i, D *S r- "> C 3J D CO, c 543 C o 3 ID fafa 4) ID — w -a V u "3 — ~fa ID t« *^ <- ID ID Pd pci V W) B BJ pci 33, -a 3 Oj fafa as - s CD " lo d d d Id d on CM ■ — i i— I ■ — i CO CO no NO i— i oqi—JTft— it--vorOLOO\ LoiS^1-* i-idLodt--'cM'I1i-HfO CM CM CM H N H 00 yC n (B rt cN 33 -o -o N SI o o s: c/) en ai cfi §=2 = 33335 C Sn*R c -3 T3 * s - 3. a) -14 -3 O S c o ■- o 3 If 5 43 a 1- LO « S3 M OS oj , — i CD M) 3- ID <_ _ -o aj aj V> — ! > ft 3 — ■ en U = s — S3 H -3 ID o "3 co cu c CD s V ft x w = -a 3 Cv -a v I- 1) eft **h V Mi a; ft X W -3-3 3 « tufa >0 * * ifl * LO vp vo i-O r— i 0> r^ to Lr 2 ^ ^ i— I i— i " " CM eg © ■* O i-h r- re i— i co O i-H ~ o< 35 1— 1 s CI t~-r— I f— VO Ci CM CM *C 3^ CM i— i 00 CO i-h CO lO Tf i— i t}> CO J rt M » : CM i— l ^ rt CM H/^coN^Hcoeof) NMc6rtfOH/\o*'c6 CM i— l I-- i— I CM CO CO CM CO £ OO <# ^ CM ciHiflwiflNOMiH CM i— i r— CM CO CO N o to to "O ^p o co « n cn 33 -c -a o CO o "3 o CO CO CO CO 2 -^ a ££■££• CM g o -a — o (3 o c .2 -3 -a £ p £ -*^ co o CU LO bj}"S £= oo -^ S CD ft C -3 -3 s CM CM CO 1 ^ CM CM CO CO CM O M a LO O "S ^ CM LO CD CD &_i o *-* *-» ^ 03 CO -a -o CD CD CD CD bfi be fc fan < < b£ bB 3 £ b£ b£ ft CD CD *j . "3 D CD CD '*- S > > co 3 < < £ 0- pS -a a-a -Q CD ft -a CD CD fa. CU ft CD U Li. b£ bfi W O -3 o ca cm bn bB V bB IS u 08 33 3 O bB C '>■ 73 -J 11 consumption records were taken for the next four weeks. The data showed that the full feed pullets ate 1.90, 1.88, 1.95, and 2.18 pounds of feed per bird per week, while the restricted pullets, with four hours feeding time, ate 1.91. 1.91, 1.95, and 1.88 pounds of feed per bird. Thus there was virt- ually no fee:! restriction during this 16- to 20-week period. Since there was an 11.2 percent restriction of feed during the 20-week period, this re- striction must have occurred before 16 weeks of age. Table 2 presents the results with pullets restricted in feed consumption on a poundage basis, when grown in confinement and on range. It would appear that equivalent feed restriction results in less delay in maturity when pullets are confinement reared as compared with range rear- ing. However, the experiments were run in different years and different feeds were used, although the stock was the same. Since year and feed may have had some effect, it cannot be said that equivalent restriction of feed results in less delay in maturity in confinement than on range. While early egg size, as measured by average weight of all eggs laid to 50 percent production, is generally larger for the restricted fed pullets, this is not always true as shown by the results of Experiment 6. Also it is evident that when egg size is measured at a specific time after the re- stricted fed pullets are in production, there is little difference between the two groups in ess size. This is due to the high correlation between egg size and chronological age of the pullet 1 13, 14) . In a given experiment the two differently fed groups of pullets are the same age at all times, hence the egg size should be approximately the same. Pullet weight was markedly affected bv the feed allowance, as would be expected. However, this weight was made up following four to eight weeks of full feeding. Surprisingly, this is accomplished without the con- sumption of additional feed. Hence feed saved by restriction during the Table 4. Summary of Results with Confinement Reared White Plymouth Rock Pullets Full Fed with Natural Daylight and Restricted Fed with 14-hour Light During the Brooding and Growing Period ; Experiment 9. Natural Daylight 14-hour Light Full Fed Restricted Fed Difference Feed restriction Feed per pullet to 20 wks. Age at 25% production Age at 50% production \ve. egg size to 50% prod. Ave. egg size during week in which rest'd pullets reached 50% production Pullet weight - - 20 wks. 24 wks. 28 wks. Feed per pullet 20-28 wks. Feed per bird to 60 wks. Eggs per bird Laying house mortality Hatching eggs, 21-27 oz/doz % — 15.6 lbs. 25.8 21.8 4.0** days 177 184 7 days 190 201 11* oz/doz 19.4 21.1 1.7* oz/doz 21.7 22.1 0.4 lbs. 5.3 4.8 0.5* lbs. 5.9 5.7 lbs. 6.1 6.0 lbs. 15.2 15.8 lbs. 102.2 98.8 3.4 no. 118.9 129.2 10.3 % 19.8 23.5 3.7 % 63.4 72.5 9.1 *. ** Significant at the 5 and 1% level of probability, respectively 12 growing period is not lost at this particular time in the production period. Likewise total feed consumption at the end of the production period main- ly reflects the difference in feed consumption during the growing period. The data for egg production, mortality, and percentage hatching eggs show small differences not always in the same direction. The results from Experiment 6 for the groups restricted 29 percent in feed intake are of interest. As mentioned previously, at this particular time we wished to measure sexual maturity delay as the result of what was felt to be a severe restriction program. For this reason confinement rearing was practiced. 30 percent restriction was chosen, and the restric- tion program started at two weeks of age. This management program re- sulted in a marked reduction of 8 pounds in feed intake with a resulting decrease of 1.2 pounds in body weight at 20 weeks of age. However, dur- ing the production period, these pullets performed as well as pullets full fed or less severely restricted during the growing period. The data in Table 3 is presented to show that light breed chickens re- spond to restricted feeding in essentially the same way as do heavy breed chickens. In order that one may see the average results to be expected from re- stricted feeding. Table 5 has been prepared. This table presents the aver- age results for Experiments 1 through 8 for the more important points under consideration. Also the difference between these averages is presented. An indication of the significance of the figures was obtained by calculation of the statistic "t" for difference between means divided by the standard error of the difference. Experiment 9 was not included in this table of average results since the feed treatments in this experiment were combined with lighting programs to measure combined effects. Studv of the data in Table 5 indicates that the outstanding advantage of restricted feeding during the growing period is the feed saved, and the re- sulting economy, in growing a pullet. An approximate 20 percent reduction in the feed allowed during the growth of a pullet results in a saving of 4 to 4.25 pounds of feed, decreases the pullet weight about one-half pound, and delays sexual maturity 8 to 9 days, without any apparent harm or major influence on results obtained during the laying period. The feed saved during the growing period is not consumed at a later date to make up the body weight as is evident from the feed consumption records ob- tained during the period when this weight is made up. Further evidence for this fact appears also in the total feed consumption data. The differ- ence in total feed consumed is essentially the difference in feed consumed during the growing period. While there is an actual delay in production of first eggs by the re- stricted fed pullets, there is considerable tendency also for the restricted fed pullets to lay at a slower rate until the body weight is made up. Since there is no appreciable difference in feed consumption at this time, it would appear that feed was being used for weight gain at the expense of egg production. Following the attainment of body size there comes in- creased production with a general tendency for the restricted pullets to reach a little higher peak of production. It is during this period that the restricted fed pullets catch up in number of eggs with the full fed pullets which started laying at an earlier age. However, since mature egg size has not been attained at this time, all of the additional eggs laid by the re- stricted fed pullets are not additional hatching eggs. Hence the end re- 13 suit is equivalent numbers of eggs for the two groups and a small increase of two or three hatching eggs per bird for the restricted fed pullets. Table 4 presents results for the combined effects of restricted feeding and artificial light on fall-hatched pullets. In general the results do not differ from those obtained in the experiments conducted with 14-hour light- ing. Likewise the results do not differ from those obtained in experiments in which lighting effects alone have been studied (10. 11). This would indi- cate that lighting effects and restricted feeding effects are not additive in altering sexual maturity and associated factors in pullets grown during the shorter daylight periods of the year. Hence either artificial lighting, restricted feeding, or the combination of both practices will produce the same end results. Artificial lighting offers the advantage of simplicity, ease in usage and low cost while restricted feeding offers the advantage of feed saving and economy although it is more difficult to apply. Table 5. Summary of Average Results from Experiments 1-8. Full Restricted Feeding Feeding Difference Feed per pullet to ter- mination of restriction lbs. 24.4 20.2 4.2* Pullet wt. at termina- tion of restriction lbs. 4.48 3.94 .54 Age at 25% production days 168 177 q ** Age at 50% production days 180 188 8 ** Ave. egg size to 50% production oz/doz 21.5 21.7 .2 Ave. egg size during week in which rest'd pullets reached 50% production oz/doz 22.2 22.4 .2 Total feed per bird lbs. 96.3 92.2 4.1 Eggs per bird no. 112 112 0 Mortality in laying house % 21 15 6 Hatching eggs, 21-27 oz. % 84 86 2 * Significant at the 5% level of probability ** Significant at the 1% level of probability In general the results from these experiments, conducted during the period from 1952 to 1958, agree with reports published during the course of this research (Milby and Sherwood, 1953; Sunde et al., 1954; Singsen et al., 1954; Davis and Watts, 1955; Schneider et a/., 1955: Milby and Sher- wood, 1956). Schneider et al. (5) were the only workers to report sig- nificantly lower mortality in the laying house (13.2 percent) for the "slow" grown pullets. They state that the exact reason for this difference in re- sults is not known. Thev suggested that in part this difference mav be due to extremely high protein feeding to the "fast" grown pullets and to severe restriction practiced on the "slow" groups for a period of six weeks after the "fast" groups were fed laving mash. The author would add also that only one experiment was reported and variability at times can become quite large. An incidental observation from these experiments has been that feather pulling and cannibalism has never been a problem. Perbaps this may be ac- counted for in part by the fact that care was always exercised that adequate feeder space was available so that all chickens could eat at the same time. 14 Summary Restricted feeding of growing pullets has been investigated in a series of seven experiments conducted over a six-year period. Heavy breed and light breed stock was used, range and confinement rearing was practiced, feed restriction on a time and poundage basis was studied, and the combined effects of artificial lighting and restricted feeding were investigated. Restricted feeding of mash on a 4-hour time basis, supplemented with whole oats to equal 25 percent of the total feed, results in only moderate feed restriction. In one experiment there was essentially no restriction of mash consumption when mash was available for 4 hours daily during the period 16 to 20 weeks of age. Restricting the feed during the growing period 20 percent or more on a poundage basis decreases feed intake, reduces pullet weight, and delays sexual maturity 8 to 9 days. Restricting the feed had no significant effect on subsequent egg production, egg weight on any calendar date, laying house mortality, or percentage of hatching eggs. Differences which did develop tended to favor restricted feeding. Range-reared and confinement-reared pullets, and heavy breed and light breed stock react in the same manner to restricted feeding. November-hatched pullets subjected to 14-hour lighting and restricted feeding react in essentially the same manner and to the same degree as pullets managed only on a restricted feeding basis. Artificial lighting effects and restricted feeding effects are not additive in altering sexual maturity and associated factors. Hence either artificial lighting, restricted feeding, or the combination of both management practices will produce the same end results. Recommendations The outstanding advantage of a restricted feeding program lies in the feed saved and the resulting economy in the cost of growing a pullet. For this reason it is recommended to those who wish to use it. Like any feeding system, good management and sound judgement are important factors in the successful operation of a restricted feeding program. Since restricted feeding differs markedly from feeding systems in com- mon usage in the past, perhaps a few suggestions and cautions for oper- ation of the program will be helpful. Suggestions 1. To be most successful, restricted feeding should be started when the pullets are six to eight weeks of age. 2. Restrict 20 percent on a poundage basis. 3. Feed twice daily. 4. Amount to feed. One of the more difficult aspects of the program is determination of the amount of feed to be used each day. Table 6 may be used as a restricted feeding guide. As the name implies, it is only 15 a guide. The actual amount of feed consumed by any full fed flock will vary with the feed, stock, season of the year, range or confinement, and size of the pullet. Table 6. Restricted Feeding Guide. Approximate Pounds of Feed per Hundred Birds per Day.* Age Heavy Breeds Light Breeds wks. 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 lbs. 11 12 13 14 15 16 17 18 19 20 21 22 23 23 23 lbs. 8 9 10 11 12 13 14 15 16 17 17 17 17 17 17 * Quantity of feed allowed may be relat- ed to age. Heavy breeds ■ — age plus five until 23 pounds is fed; light breeds ■ — age plus two until 17 pounds is fed. Cautions 1. Size of flock. In confinement rearing or where feed is placed in troughs, small groups of pullets (400- 500) are more successfully managed than large groups (1000 or more). The pullets become very hungry and will crowd around the attendant and the feeders at feeding time. Losses can occur from piling and smothering. 2. Feeding space. Pullets on a re- stricted feeding program need enough feeder space so that all pullets can eat at the same time. Allow at least six inches of feeder space per pullet or five five-foot troughs per hundred pul- lets. Without adequate feeder space a restricted feeding program will not be successful. 3. Feeding schedule. Pullets on a restricted feeding program adapt themselves to the feeding schedule. At feeding time they are very hungry ready and to feed on feather picking and other vices. Feed on schedule. anxious for feed. Failure schedule may lead to drug 4. Drug medication in the feed. Restriction of feed intake also restricts intake. Hence, recommended levels of a preventative drug in the feed may not be adequate in a restriction program. 5. Disease problems. If disease develops, full feed until the problem is corrected. 6. Culling. At housing time culling for health only should be practiced. 7. Type of feed. While the general features of the restricted feeding program as recommended are applicable to use of several types of feed, the Feeding Guide is based upon the feeding of a high energy all-mash or "complete" feed. One should not attempt to feed a low energy, bulky, or more fiberous feed on a restricted basis. For those who wish to feed oats or to make other modifications in the feeds used, it is suggested that you consult with your feed supplier in order that the right type of feed may be selected. 16 References 1. Milby, T. T. and D. H. Sherwood, 1953. "The effect of restricted feeding on growth and subsequent production of pullets," Poultry Sci.. 32: 916. 2. Sunde, M. L., W. W. Cravens, H. R. Bird, and J. G. Halpin, 1954. 'The effect of complete and incomplete growing diets on subsecpuent performance of the laying hen." Poultry Sci. 33: 779. 3. Singsen. E. P.. L. D. Matterson, Anna Kozeff, and Lois Decker Stinson, 1954. "The effect of feeding high and low efficiency rations to growing pullets on their subsecpuent laying performance." Poultry Sci. 33: 1081. 4. Davis, W. M. and A. B. Watts, 1955. "The effect of ration treatments during the various stages of the chicken's life upon the subsequent performance of laying hens." Poultry Sci. 34: 1231. 5. 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. o. Milby, T. T. and D. H. Sherwood, 1956. "The influence of feed intake during the growing period on the subsequent performance of laving hens." Poultry Sci. 35: 863. 7. New Hampshire Agricultural Experiment Station Bulletin 394, 1952. "Report of the Director of the New Hampshire Agricultural Experiment Station." 8. New Hampshire Agricultural Experiment Station Bulletin 409, 1954. "Report of the Director of the New Hampshire Agricultural Experiment Station." 9. New Hampshire Progress Report, 1955. Vol. 1, No. 2. 10. New Hampshire Agricultural Experiment Station Bulletin 402, 1953. "Report of the Director of the New Hampshire Agricultural Experiment Station." 11. Tomhave, A. E., 1954. "Influence of artificial lights during rearing on the egg production of October hatched New Hampshires." Poultry Sci. 33: 725. 12. Skoglund, W. C, A. E. Tomhave, and C. W. Mumford, 1951. "Egg weight in New Hampshires hatched each month of the year." Poultry Sci. 30: 452. 13. Funk, E M., 1935. "Relation of body weight and egg weight in the domestic fowl." Poultry Sci. 14: 232. 14. Waters, N. F., 1937. "Body weight, egg weight, sexual maturity, and growth rate in the domestic fowl." Poultry Sci. 16: 305. 17