Reproduction in Turkey Hens as Influenced by and Protein Intake and the Environment F. L. CHERMS, M. G. STOLLERAND J. J. MACILRAITH Nicholas Turkey Breeding Farms, Inc., Sonoma, California 95476 AND H. R. HALLORAN Halloran Research Farm, Inc., Modesto, California 953 (Received for publication November 28, 1975) ABSTRACT June hatched female turkeys of an egg laying strain were subjected to two protein levels, either 15.6 or 18.5% protein, and two environmental regimes, either a natural day () or a 6-hr. day of 5.4 lx. () in a 2 x 2 factorial design during the prebreeder period of to 32 weeks. Birds of each treatment were randomized into four breeder treatments when lit at 32 weeks. performance traits were compared where hens were fed either 35 or g. of protein per hen per day on either a 12-hr. day with 53.8 lx. (E4) or a minimum 14-hr. day with a minimum intensity of 1 lx. (E3). treatment significantly influenced body weight at lighting where hens reared on 15.6% protein and a 6-hr. day were the lightest while those on the 18.5% protein and a natural day were the heaviest. However, by week 35 these differences had disappeared. Performance traits of age at first egg, egg production, hatchability, broodiness, and egg weight were not affected by the nutritional regimes studied during either the prebreeder or breeder phase. Significant environmental influences existed for age at first egg, egg production, broodiness, hatchability, and body weight. The /E4 regime significantly increased the age at first egg over the other three environmental combinations. Egg production was significantly reduced by the /E4 treatment when compared to E1/E4 and / E3. Broodiness was adversely affected by both the E4 and the / E4 regimes. Hatchability was significantly higher with the E4 environment when compared to E3. In the last weeks of the 26 week production period, hens on the E3 regime were heavier than those on the E4. INTRODUCTION PROTEIN requirements of turkey breeders have been studied by several workers. In general, the tests have been conducted using feeds of different protein levels with no attempt made to regulate daily protein intake. To study the absolute daily requirement for protein, information needs to be obtained on daily feed consumption and then to maintain as near as possible a constant daily intake of protein in terms of grams of protein consumed per hen per day. In a few studies protein requirements have been reported on a basis of grams of protein per hen per day whereas in others sufficient data, including consumption figures, have been reported so that calculations can be made on such a basis. In these studies a rather wide range in requirement has been reported. POULTRY SCIENCE 55: 1678-1690, 1976 Jensen and McGinnis (1961) found no difference in either egg production or hatchability in hens receiving either 36 or g. of protein per day. In a comparison of daily protein intake of 22, 25, and 33 g., Minear et al. (1972) reported no difference in egg production. Similarly, Waibel (1974) found no performance differences in hens receiving 26, 30, 34 or 41 g. of protein per day. According to Atkinson (1973) large breeder hens require 45 to 55 g. of protein per day. The present study was designed to examine, as one variable, daily protein intake of a medium range (35 g.) and an upper reported requirement ( g.). Many environmental factors are known to have an influence on breeder performance with a primary factor being light both during the prebreeder and breeder periods. Studies on light have included not only the length 1678
PROTEIN AND ENVIRONMENT OF TURKEY HE 1679 TABLE 1.Dietary regime used for day 1 through week 21 Feed Starter #1 Starter #2 Starter #3 Grower #1 Grower #2 Grower #3 Holding Ration With calculated protein and energy values Feeding time % Protein Energy kcal./kg. 0-2 Weeks 3-5 Weeks 6-8 Weeks 9-11 Weeks 12-14 Weeks 15-17 Weeks 18-21 Weeks 30.0 27.3 24.6 21.1 18.5 16.8 15.6 2800 2840 2860 2900 2930 2980 2740 of the photoperiod but also the intensity of the light during that period. One of the first studies on intensity was that of Asmundson et al. (1946) where it was reported that the minimum intensity needed for maximum response in bronze hens was 22 lx. Garland et al. (1961), using Medium White hens, obtained the highest performance with light intensity of 96 to 129 lx. In Large White hens, McCartney (1971) found no production differences in a comparison of 16.1 and 32.3 lx. during the breeder period. Thomason et al. (1972) compared 5.4 and86.1 lx. for Large White breeders and found no difference in egg production. In practical turkey breeding operations a photoperiod of 14 to 15 hr. is quite common. The initial study on the effect of the length of the photoperiod on performance of turkey breeder hens was that of Asmundson and Moses (19) who found that 13 hr. of light was the minimum amount for good production. In caged Small Whites stimulated at 23 weeks with 21.5 lx., Ogasawara et al. (1962) reported a better response to 14 hr. rather than 12 hr. When hens were stimulated with 10.7 to 32.3 lx. at 30 weeks, Wilson et al. (1962) found 14 hr. to be better than 12 hr. In the study reported here, reproduction performance of spring hatched hens grown during the prebreeder period on a 6-hr. day with low intensity (5.4 lx.) was compared to that of hens grown on a natural day with a minimum intensity of 1 lx. A comparison was also made of a breeder regime of a 12-hr. day with 53.8 lx. of light with a minimum day of 14 hr. and a minimum intensity of 1 lx. EXPERIMENTAL PROCEDURE Female poults of an egg laying strain, hatched June 13, 1973, were placed under gas hovers at a density of 300 poults per hover the morning after the hatching day. The birds were brooded and grown in buildings with curtained openings along each side of the building. At 13 weeks of age the hens were moved to another building and randomly placed in 12 pens (3.2 x 4.27 m.) of 36 birds each. When weeks of age, half of the pens were totally enclosed and the hens were subjected to a 6-hr. day with a light intensity of 5.4 lx. Hereafter this treatment is designated as. The remaining pens were maintained on a natural day length with no artificial illumination (). At 22 weeks of age, the birds were randomly selected down to 24 birds per pen and remained at that density until lighting time (32 weeks of age) when they were further reduced to 8 pens of birds per pen by removing the poorest birds. Until 22 weeks of age, all birds were fed the dietary regime as shown in Table 1. At that time half of the birds under 6 hr. of light and half of those on a natural day length were placed on an 18.5% protein grower feed (Table 2). The other half of the birds in each environment were maintained on a 15.6% protein holding feed (Table 2). Thus there were four treatment groups during the growing period: 1) natural day15.6% protein
1680 CHERMS, STOLLER, MACILRAITH AND HALLORAN TABLE 2.Percent composition of prebreeder diets 15.6% 18.5% Protein Protein holding Ingredient grower feed Corn Milo Rice bran, high fat Whey product, dried Alfalfa, 18% protein Soybean meal, -1/2% protein Cottonseed meal, 44% protein Nuf ac' Limestone Defluorinated phosphate Salt DL-Methionine Vitamin and trace mineral premix 2.0 39.7 4.8 2.3 10.9 10.0 5.8 0.6 2.5 0.25 0.02 10.0 37.5 23.0 8.12 2.0 7.5 5.0 1.75 0.25 0.02 1.88 1 Feedstuffs Processing Co., San Francisco, CA 94107. 2 Unit per kilogram: Vitamin A-6340 I.U., Vitamin D 3-1930I.C.U., Riboflavin-4.96mg., Choline- 282 mg., d-pantothenic Acid-7.99 mg., Niacin-31.7 mg., Vitamin B ]2-6.89 mg., Folic Acid-0.36 mg., Menadione Sodium Bisulfite Complex-2.76 mg., Vitamin E-5.24 I.U., Manganese-65 mg., Iodine- 1.23 mg., Copper-2.25 mg., Zinc-75 mg. holding feed, 2) natural day18.5% protein growing feed, 3) 6-hr. day15.6% protein holdingfeed,and4)6-hr. day18.5%protein growing feed. At 32 weeks of age the birds were randomized into eight pens of hens in such a manner that each breeder pen contained five hens from each of the four growing treatment groups. AH hens were saddled and the pens were set up with trapnests. One block of four pens was in a total confinement house where light and temperature were controlled. In this situation the hens received a 12-hr. day with a maximum temperature of 30.1 C. and a light intensity of 53.8 lx. (E4). The other block of four pens was in the other end of the same building but with open sides and the hens received a minimum of 14 hr. of light and a minimum light intensity of 1 lx. (E3). Within each environmental block there were two pens that were given 35 g. of protein daily and there were two pens given g. of protein daily. Feed consumption was determined daily and the hens received one of the diets shown in Table 3 based on their daily consumption. This was done in order to reach either the 35 or g. intake level. Each mix of each feed was assayed by a private testing laboratory for protein, calcium, and phosphorus levels. Protein intake was determined using the assay values rather than calculated levels. During the entire course of the experiment the following data were obtained: 1. Biweekly body weight from 13 to 32 weeks 2. Weekly body weight from 32 to 35 weeks 3. Biweekly body weight from 35 to 59 weeks 4. Daily feed consumption from 32 to 59 weeks 5. Daily protein intake from 32 to 59 weeks 6. Egg production, fertility, hatchability, and egg weight during 26 weeks of production. All body weight data was obtained to the nearest tenth of a pound and converted to kilograms. Egg production is given as the total number of eggs laid. Throughout the duration of the test weekly sets were made to obtain fertility and hatchability data. Fertility data are based on candling at seven days of incubation and a breakout of clear eggs. All hens were inseminated from the same pool of neat semen and received.025 ml. biweekly during the duration of the experiment. On a given day, all hens were inseminated either between 8:30 and 10:00 a.m. or 2:00 and 3:30 p.m. All eggs laid were individually weighed to the nearest gram. Where appropriate, data were subjected to
PROTEIN AND ENVIRONMENT OF TURKEY HE 1681 TABLE 3.Percent composition of breeder diets Ingredient Milo Corn Dehydrated alfalfa, 18% protein Soybean meal, -1/2% protein Limestone Nufac 2 Vitamin and trace mineral premix 3 Molasses Defluorinated phosphate Rice bran, high fat Whey product, dried Salt DL-Methionine Animal fat Safflower meal, 42% protein Calculated energy (kcals./kg.) 12% (13.1%)'.67 21.98 5.99 5.62 4.00 2. 2.00 1.70 0.25 0.04 2870 14% (14.5%) 43.45 24.98 5.87 7.37 4.62 2.75 2.00 0.28 0.05 0. 1.88 28 Calculated protein level 16% 18% % (15.8%) (17.9%) (19.8%) 36.96 24.97 2.62 9.12 5.24 3.00 2.37 0.30 0.06 1.87 7.24 28 37.44 24.75 2.00 16. 4.37 2. 1.90 0.25 0.06 4.00 2800 30.22 24.99 2.00 24.99 4.75 2.75 2. 0.28 0.07 0.25 2800 22% (21.5%) 47.85 2.00 28.61 5.25 3.00 2.52 0.30 0.10 2.87 2. 2800 24% (23.1%) 15.37 27.22 2.00 35.75 5.25 3.25 2.75 0.33 0.08 3.00 2780 'Actual protein composition based on assay. 2 Feedstuffs Processing Co., San Francisco, CA 94107. 3 Units per kilogram: Vitamin A-l 1,01.U., Vitamin D 3-33101.C.U., Riboflavin-8.27 mg., Choline-5 mg.,d-pantothenicacid-16.5mg.,niacin-55.1 mg., Vitamin B, 2-12.4 mg., Folic Acid-1.10 mg., Menadione Sodium Bisulfite Complex-4.96mg., Vitamin 4.11.U.,Biotin-0.11 mg., Manganese-65 mg., Iodine- mg., Iron-23 mg., Copper-2.25 mg., Zinc-75 mg. analysis of variance testing to determine possible statistical differences in the data. RESULTS AND DISCUSSION 1. Feed consumption and protein intake. Daily feed consumption and protein intake during the prebreeder period of from to 32 weeks of age for each of the four treatments are shown in Tables 4 and 5. The hens TABLE 4.Daily feed consumption (grams), by treatments, during the prebreeder period 15.6% 15.6% 18.5% 18.5% Protein Protein Protein Protein Age holding holding growing growing (weeks) feed/ feed/ feed/ feed/ 262 301 266 285 266 266 226 262 2 262 222 226 305 311 260 259 236 2 239 267 2 274 226 213 on the 6-hr. day () consumed 12% less of the 15% protein holding feed and 9% less of the 18% protein grower feed than did the hens under natural light (). During the time span of this phase of the experiment, the hens under natural conditions were exposed to day length ranging from 10-1/2 hr. ( weeks) to 9-3/4 hr. (32 weeks). Average daily protein intake for the entire period ranged from a low of 38 g. for the hens on a 15% TABLE 5.Daily protein intake (grams), by treatments, during the prebreeder period Age (weeks) 22 24 26 28 30 32 15.6% Protein holding feed/ 41 47 42 44 43 41 15.6% Protein holding feed/ 35 41 39 41 35 34 18.5% Protein growing feed/ 57 44 46 18.5% Protein growing feed/ Avg. 274 241 270 245 Avg. 43 38 44 37 46 42 40
1682 CHERMS, STOLLER, MACILRAITH AND HALLORAN TABLE 6. Average daily grams of feed per hen summarized by weeks beginning at lighting Week 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 21 22 23 24 25 26 27 28 Avg. g./e3 Pen 1 Pen 4 302 304 301 302 231 254 217 231 243 259 221 224 210 213 190 211 2 6 9 219 212 229 224 233 222 242 237 242 239 2 246 274 254 273 7 241 233 247 219 257 244 261 237 245 237 242 2 266 235 2 221 239 254 243 231 231 233 246 35 g./e3 Pen 2 Pen 3 316 300 315 305 2 234 227 224 233 239 234 2 226 211 210 8 215 7 223 215 235 223 2 239 2 236 242 238 246 236 247 245 254 240 234 228 243 230 244 237 240 228 2 232 242 217 252 224 252 9 234 217 230 225 235 229 244 232 protein holding feed/ regime to a high of g. for the hens on an 18% protein grower feed/ regime. The lower group consumed 22% less protein than did the highest group. Protein intake for hens on the other two treatments were intermediate between the extremes. During the breeding phase of the experiment, the hens on the daily protein intake of 35 g. consumed an average of 234 g. of feed daily while those on the g. level consumed 235 g. of feed (Table 6). This difference was not significant (Table 7). There was however a significant difference in feed consumption between hens on the two environments (Table 7). Hens in the confined environment consumed, an average of 230 g. of feed per day versus 239 g. for those birds in semi-confinement. When the consumption figures for each pen are examined it is rather obvious that two pens, namely pens two and g.,/e4 Pen 14 Pen 15 278 293 295 295 261 263 232 227 233 237 237 243 3 214 175 192 165 193 180 6 194 217 2 210 212 219 237 232 260 242 258 237 247 241 237 2 229 226 234 240 232 229 241 218 229 232 234 234 232 230 211 231 228 246 237 2 229 233 35 g.,/e4 Pen 13 Pen 16 278 276 294 300 246 271 214 235 238 234 214 222 192 210 178 186 186 181 199 197 218 217 238 213 235 225 239 234 227 226 245 238 239 235 230 237 229 232 235 230 230 226 229 221 233 211 228 218 2 240 226 229 227 240 237 2 229 230 four, had higher consumption figures than the other six pens. This difference may be accounted for by the fact that pens two and four are located on the west side of the building and receive the direct effect of the brisk westerly winds that blow at the location of the experimental house. There are definite changes in feed consumption during the different weeks of the TABLE 7.Analysis of variance for feed consumption data during the breeder period Source of variation Protein intake (P) Environment (E) Week (W) P x E P x W E x W P x E x W Error Total df. 1 1 27 1 27 27 27 112 223 1% level of significance. MS.0006.0197.02.0000.0007.0011.0003.0005 F 1.11 37.79 38.77 0.02 1.32 2.02 0.59
PROTEIN AND ENVIRONMENT OF TURKEY HE 1683 7 14 21 WEEKS FROM LIGHTING FIG. 1. Average daily feed consumption, by weeks, for all hens during the breeder period. laying period (Table 7). Consumption reached its highest point of 301 g. the week following lighting time and then dropped to its lowest point of 194 g. at the 8th and 9th weeks following light (Fig. 1). Then there is a gradual rise until about the 14th or 15th week when consumption levels off. It is interesting, that at a time following peak egg production (subsequent section), feed consumption reached its lowest point. With the procedure that was followed of altering the feeds to maintain a fairly constant intake of protein, the hens were receiving the desired levels of protein even at the time of the low levels of feed consumption. This can be seen from the data in Table 8 where the protein intake per hen per day given as weekly averages are shown. It is also evident from this data that the desired levels of 35 and g. were attained. 28 The relationship between temperature and feed consumption was examined using both the average weekly high and low temperatures for each environmental situation. The average weekly high temperatures ranged from 12.4 C. to 34.5 C. for the semi-confined birds and from 12.1 C. to 30.1 C. for the confined hens. Using standard regression procedures, no relationship was found to exist between either the average weekly high or low temperatures and weekly feed consumption. 2. Body weight. Throughout the course of the experiment, body weight was obtained either at weekly or biweekly intervals. Weights were also obtained during the preexperimental period from 13 to weeks. The weight data for weeks 13 to 59 as related to prebreeder treatment are shown graphically in Fig. 2. Birds were first placed in the
1684 CHERMS, STOLLER, MACILRAITH AND HALLORAN TABLE 8.Grains of protein 1 per hen per day during the breeder period Week 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 21 22 23 24 25 26 27 28 Avg. 35 Grams E3 E4 45 42 43 41 35 36 38 37 37 39 35 34 36 36 37 35 36 36 37 37 36 37 38 36 37 36 36 36 36 34 36 37 36 35 34 35 35 35 36 34 34 34 35 34 36 36 36 35 35 36 36 35 35 33 37 35 36.5 35.9 E3 54 45 45 55 47 45 46 52 52.4 Grams" 'Calculated from analysed protein values. E4 52 47 52 46 41 40 47 52.0 and environments ( weeks) followed by the two protein levels at 22 weeks. At 22 weeks the hens averaged 7.16 kg. while those on the regime were 6.70 kg. When the two feeding regimes were superimposed at 22 weeks an additional spread in body weight was noted. One purpose of the four growing regimes was to try to produce hens at lighting time that varied in body weight so as to study possible relationships between body weight at lighting and subsequent reproductive performance. When the body weight data obtained at lighting (32 weeks) was statistically analyzed greater effects were attributable to the growing environment than to protein level (Table 9). At this age the heaviest group (9.37 kg.) had been on a regime of 18.5% protein/. They were followed in descending order by 1) 15.6% protein/ (9.24 kg.), 2) 18.5% protein/ (9.08 kg.), and 3) 15.6% protein/ (8.79 kg.). As shown in Table 9, the influence of the prebreeder diet disappeared by week 33. From week 32 to week 34 the body weight differences attributable to prebreeder environment gradually declined to the point that by week 35 all differences had disappeared. Even though the treatments applied to the hens had produced significant body weight differences at lighting time these effects were not long lasting during the period of time immediately following lighting. The two protein levels fed during the breeding phase of the experiment did not influence body weights (Fig. 3 and Table 9). The breeder environment did however have a significant effect on body weight during the last eight weeks of the breeder period. By week 59 the hens in the E3 environment weighed 9.07 kg. or 0.26 kg. more than the hens in the E4 regime. Even though there were slight differences in total feed intake between the two environmental conditions the system employed to maintain similar levels of protein intake would negate this fact as affecting body weight. Comparisons were made between layers and non-layers as to body weight at week 59 to determine if the reproductive state may have an influence on weight at that age. Data for all surviving hens were utilized and those laying at the termination of the test weighed an average of 8.94 kg. while those hens classified as non-layers weighed 8.92 kg. There was no influence of reproductive state on body weight at this age. When hens exhibit broodiness they spend more time on the nest (Haller and Cherms, 1961) and thus probably have a reduced feed intake during this time (Thomason et al., 1972). This might influence body weight to some degree. However when the final body weight data were compared, there were no differences between those hens that exhibited broodiness during the laying year (8.86 kg.) and those hens that did not express this trait (8.94 kg.). Thus the differences in body
PROTEIN AND ENVIRONMENT OF TURKEY HE 1685 10-1 I I I I 18% PROTEIN-NATURAL DAY 18% PROTEIN-6 HR. DAY 15% PROTEIN-NATURAL DAY 15 /oprotein-6 HR. DAY 32 42 52 AGE (WEEKS) FIG. 2. Effect of prebreeder diet and environment on body weight of turkey hens during the prebreeder and breeder periods. 1. Main effects protein (A) environment (B) protein (C) environment (D) 2. Two-way interactions A x B A x C A x D B x C B x D C x D 3. Three-way interactions A x B x C A x B x D A x C x D B x C x D 4. Four-way interactions A x B x C x D TABLE 9.Location of significant body weight effects Source of variation Wk. 32 Wk. 33 Wk. 34 Wk. 35 Wk. 37 Wk. 45 Wk. Wk. 53 Wk. 57 Wk. 59.05. =.01. =.001.
1686 CHERMS, STOLLER, MACILRAITH AND HALLORAN 10.0 o GO y.b H X CD LU 5 If/ > Q O 9.0 8.5 H 35 1 'A \ v.. V odu 14IIH. DAY 35G-12HR. DAY 22G-14HR. DAY - - - 22G-12HR. DAY - 40 45 AGE (WEEKS) / /v. 55 60 FIG. 3. Effect of breeder diet and environment on body weight of turkey breeder hens. weight attributable to breeder environment can not be explained by either protein intake, reproductive state or broodiness. 3. Reproductive data. All reproductive data have been summarized in 2 x 2 x 2 x 2 tables and the data subjected to a randomized block analysis of variance (Steele and Torrie, 1960). In Tables 10-14 each cell in subsection 1 of section A represents data from 10 individual hens obtained from two groups of five hens housed in two pens. Data is additionally summarized to show significant relationships when statistical analysis indicated that the differences were significant. The turkey hen generally responds rather uniformly to the stimulatory effects of lighting (stimulight) when it reaches breeder age. In this study, significant environmental effects were noted on the age, in days, of first egg (Table 10). Hens that were maintained on a prebreeder light regime of 6 hr. and then placed on a 12-hr. period of stimulight were slower by about four days in reaching first egg than any other environmental treatment group. At the time the hens were subjected to stimulight (January 24), the natural day length at the latitude at which this test was conducted was 9 hr. and 47 min. The increase in day length at the time of stimulighting ranged from 2 hr. 13 min. for birds on the E1/E4 regime to 8 hr. for those on the /E3 regime. The hens that were significantly delayed in reaching sexual maturity (/E4 regime) had a 6 hr. increase in day length. Obviously the magnitude of the increase in day length was not the only factor in the initiation of oviposition. Considerable variation existed in the intensity of light between the controlled and uncontrolled en-
PROTEIN AND ENVIRONMENT OF TURKEY HE 1687 TABLE 10.Age at first egg (days) as summarized by prebreeder and breeder treatments with significant effects noted A. Data 1) Treatment groups Protein Environment 15.6% 18.5% 2) Environmental treatments E-3 2.7 2.6 2.5 2.6 35 Grams Grams E-3 2.4 2.1 2.5 2.2 2.1 2.6 256.0 2.0 E-3 2.7 2.5 2.1 254.4 B. Significant relationships (5% level). 1) E1/E3 (2.7) and E1/E4 (2.5) and /E3 (2.1) vs. /E4 (254.4) vironments. During the prebreeder period the intensity of light in the controlled environment was a constant 5.4 Ix. and during the breeder period the intensity was a constant 53.8 lx. In the uncontrolled environment the light intensity ranged from a low of 1 lx. on cloudy days to 1400-1600 lx. on sunny days. Thus hens grown and laid in the lower light intensity were the slowest in reaching sexual maturity. Nestor and Brown (1972) found no influence of light intensity on age at first egg. However, the intensity they used during the light restricted prebreeder period 2.4 254.4 2.2 255.6 was higher (33 lx.) than that used in this study while the light intensity studied during breeder phase was generally below (18.3 to.6 lx.) the levels used here. The two studies are therefore not totally comparable. Of particular interest is the influence of the E1/E3 and E1/E4 environments on age at first egg. In the former instance the increase in day length at stimulighting was 4 hr. 13 min. and for the latter instance it was 2 hr. 13 min. Both of these groups responded as similarly to stimulight as did the /E3 group with an 8 hr. increase in day length. In each TABLE 11.Number of eggs laid per hen for a twenty-six week production period as summarized by prebreeder and breeder treatments with significant effects noted A. Data 1) Treatment groups Protein Environment 15.6% 18.5% 2) Environmental treatments E-3 107.6 108.2 102.1 107.6 35 Grams Significant relationships (5% level). 1) E1/E4 (109.3) and /E3 (109.1) vs. /E4 (95.9) 112.8 106.3 115.8 84.7 E-3 102.0 109.1 E-3 103.2 112.6 95.1 107.8 109.3 95.9 Grams 103.3 86.6 105.3 106.3
1688 CHERMS, STOLLER, MACILRAITH AND HALLORAN TABLE 12.Percent of hens exhibiting broodiness as summarized by prebreeder and breeder treatments with significant effects noted A. Data 1) Treatment groups Protein Environment 15.6% 18.5% 2) Environmental treatments 35 Grams E-3 30 40 3) protein and environmental treatments Protein 35 g. g. 0 30 E-3 22.5.0 Grams E-3 10 10 22.5.0 21.3 36.3 Environment E-3 27.5 15.0 25.0 47.5 Significant relationships (5% level). 1) E3 (21.3%) vs. E4 (36.3%) 2) E1/E3 (22.5%) and /E3 (.0%) and E1/E3 (22.5%) vs. /E4 (.0%) 3) g./e3 (15.0%) vs. g./e4 (47.5%) of these instances, in at least one of the periods the hens were exposed to high light intensity. That level of light may have primed more hens to respond to stimulight. As with age at first egg, the two levels of protein used during the breeding period 40 60 30 60 did not influence egg production (Table 11). Several studies have been reported in the literature relative to protein and reproduction. However, in most of these studies protein was not reported on a gram per hen per day intake basis but rather as a percent of the TABLE 13.Percent hatch of eggs set as summarized by prebreeder and breeder treatments with significant effects noted A. Data 1) Treatment groups Protein Environment E-3 15.6% 18.5% 2) Environmental treatment Significant relationships (5% level). 1)E4(73.1%) vs. E3 (67.4%) 68.0 60.1 62.4 67.7 35 Grams E-3 75.3 75.2 62.3 71.1 E-3 67.9 66.8 67.4 72.4 70.6 68.6 68.9 72.6 73.6 Grams 72.4 80.5 80.2 67.4
PROTEIN AND ENVIRONMENT OF TURKEY HE 1689 TABLE 14.Egg weight, in grams, for all eggs laid in twenty-six weeks of production as summarized by prebreeder and breeder treatments A. Data 1) Treatment groups 35 Grams Grams Protein Environment E-3 E-3 15.6% 88/7 WA 89/2 89i)" 89.4 88.3 89.1 85.2 18.5% 88.3 86.4 90.1 89.8 85.6 88.7 87.6 89.3 B. Significant relationships 1) None ration used. Since many things such as body size, genetic egg production potential, and various environmental factors can influence feed intake and thus daily protein intake, the protein requirement is best studied on a daily intake basis. In those published reports where sufficient information has been reported, calculations have been made on the grams of protein consumed per day. Wide ranges exist in what has been reported as requirements for protein going from about 22 g. to 45-55 g. (loc. cit.). Within the confines of this study no beneficial result occurred when 35 g. were compared to g., generally concurring with the majority of reports. Additional studies are planned to study lower levels. Significant environmental effects on egg production were noted in that the E1 / E4 and /E3 groups laid significantly more eggs than the /E4 group. The hens on the /E3 regime were intermediate between the extremes but not significantly different from either. Thus there appears to be an interaction between light intensity and day length during the prebreeder period with light intensity and day length during the breeder period. Hens will lay well on a 12-hr. day of 55 lx. if they are exposed to high light intensity during the prebreeder period. Conversely, hens on low light intensity and short days during the prebreeder period do not lay well if they are exposed to a 12-hr. day of 55 lx. intensity. The 55 lx. intensity is within the generally reported acceptable range reported for several types of turkeys (loc. cit.). It is of interest to note a possible further compounding effect on the influence of lighting in that Nestor and Brown (1972) reported strain differences in response to light intensity within a range of from 18.3 to.6 lx. in a 14-hr. day. They found that large bodied strains responded favorably to increasing intensity whereas medium strains did not. Conversely, Thomason et al., (1972) could find no difference in response with large white turkeys to 5.4 or 86.1 lx. These reports suggest that strain differences in response to light may be quite real. Broodiness is an integral part of total egg production. Utilizing the detection method of Haller and Cherms (1961) it was possible to study the effects of the environment and protein intake on this trait. A striking effect of the environment on broodiness appeared with the breeder environment where hens in E3 had an incidence of 21.3% broodiness while those in E4 had a significantly higher incidence of 36.3% (Table 12). Most of this effect was accounted for by the significant interaction of the and E4 environments. Furthermore, there was a significant interaction between the g. protein level and the environment, where the hens fed g. in E3 had a significantly lower incidence of broodiness than those on the E4 regime. This type of finding has not previously been reported and needs additional study. The significant increase in age at first egg and
1690 CHERMS, STOLLER, MACILRAITH AND HALLORAN the incidence of broodiness of the /E4 regime undoubtedly led to the lower egg production of that regime. Hatchability was not influenced by the two levels of protein (Table 13). Hens on the 35 g. level had an average hatch of set of 67.8% as obtained in 23 settings during the duration of the test. Those receiving the g. level hatched at a 72.6% rate. The lack of effect of protein level agrees with the findings of Jensen and McGinnis (1961) for similar protein levels. There was a significant (5%) effect of breeder environment on hatch in that the eggs of those hens on the E4 regime hatched at a level of 73.1% and those on the E3 regime hatched at 67.4%. This has not been previously reported and may simply be a spurious finding. More studies are planned to examine this further. During the course of this test, weight data was obtained for all eggs that were laid. As seen in Table 14 neither protein level during the prebreeder or breeder period nor the environmental regimes studied during these periods influenced egg weight. ACKNOWLEDGEMENT The authors wish to acknowledge the council and assistance of Herbert S. Wilgus, San Rafael, California during the course of this study. Also acknowledged is the statistical evaluation of the data by Sherman Bielfelt of Nicholas Turkey Breeding Farms, Inc. REFERENCES Atkinson, R. L., 1973. Nutritionthe key to a suc- cessful dark house. Texas Turkey Industry Day Reports 1972 and 1973, pp. 25-30. Asmundson, V. S., F. W. Lorenz and B. D. Moses, 1946. Influence of light intensity on ovulation in turkeys. Poultry Sci. 25: 346-354. Asmundson, V. S., and B. D. Moses, 19. Influence of length of day on reproduction in turkey hens. Poultry Sci. 29: 34-41. Garland, F. W., Jr., R. C. Eaton, D. E. Greene, H. L. Wilcke and R. M. Bethke, 1961. Duration and intensity of light for out-of-season egg production in turkeys. Poultry Sci. 40: 1406-1407. Haller, R. W., and F. L. Cherms, Jr., 1961. A comparison of several treatments on terminating broodiness in Broad Breasted Bronze turkeys. Poultry Sci. 40: 155-163. Jensen, L. S., and J. McGinnis, 1961. Nutritional investigations with turkey hens. 1. Quantitative requirement for protein. Poultry Sci. 40: 288-290. McCartney, M. G., 1971. Reproduction of turkeys as affected by age at lighting and light intensity. Poultry Sci. : 661-662. Minear, L. R., D. L. Miller and S. L. Balloun, 1972. Protein requirement of turkey breeder hens. Poultry Sci. : 40-43. Nestor, K. E., and K. I. Brown, 1972. Light intensity and reproduction of turkey eggs. Poultry Sci. : 117-121. Ogasawara, F. X., W. O. Wilson and V. S. Asmundson, 1962. The effect of restricting light during the adolescent period on reproductive performance in turkeys subsequently exposed to a 12-, 14-, and -hour day. Poultry Sci. 41: 1858-1863. Steele, R. G. D., and J. H. Torrie, 1960. Principles and Procedures of Statistics. McGraw-Hill Book Company, Inc., New York, New York. Thomason.D. M., A. T. Leighton, Jr. and J. P. Mason, Jr., 1972. A study of certain environmental factors on the reproductive performance of Large White turkeys. Poultry Sci. : 1438-14. Waibel, P. E., 1974. Protein and unidentified nutritional factors for the turkey breeding flock. Proc. 35th Minnesota Nutr. Conf. pp. -59. Wilson, W. O., F. X. Ogasawara and V. S. Asmundson, 1962. Artificial control of egg production in turkeys by photoperiods. Poultry Sci. 41: 1168-1175. SEPTEMBER 14-17, 1976. SECOND NUTRITION CONFERENCE, MUNICH, SEPTEMBER 22-23, 1976. SYMPOSIUM ON LABORATORY ANIMAL HOUSING, NATIONAL ACADEMY OF SCIENCES ITITUTE OF LABORATORY ANIMAL RESOURCES