Prebreeder Period Research Articles

The Effect of Protein Level Fed During the Prebreeder Period on Performance of Large White Turkey Breeder Hens After an Induced Molt

An experiment was conducted to examine the effects of prebreeder protein levels on reproductive performance Large White turkey breeder hens after an induced molt. One hundred and sixty-eight, Nicholas Large White turkey breeder hens were fed either 8, 12, or 16% CP diets (2,904 kcal ME/kg) during the prebreeder period from 56 to 64 wk of age. All hens were photostimulated with 15.5h of light/d and fed a standard 16% CP breeder ration from 64 to 87 wk of age. Feed intake, plasma triglyceride concentration, reproductive performance, and body weight were regressed on age and prebreeder dietary protein intake using a general linear model.Prebreeder protein intake increased linearly as dietary CP increased. Treatments did not affect prebreeder feed consumption or subsequent egg production. Egg weight and breeder feed consumption were greatest for hens fed 12% CP during the prebreeder period. Plasma triglyceride and body weight increased as prebreeder dietary CP increased. Body weight increased from 56 to 87 wk in a cubic response as the hens aged. Feed consumption increased during the prebreeder period and decreased during the breeder period. Plasma triglyceride content was not affected by turkey hen age or stage of production.

Effect of Body Weight, Feed Allowance, and Dietary Protein Intake During the Prebreeder Period on Early Reproductive Performance of Broiler Breeder Hens

In Experiment 1, two groups (n = 180) of breeder pullets were selected at 16 wk from two larger groups with BW of either 1,591 ± 43 (LBW) or 1,988 ± 59 g (HBW). From 16 wk of age until a peak feed allotment of 159 g per bird per day, weekly feed allowances were increased in a low (LOW), medium (MED), or high (HIGH) manner. There were significant differences (P<.05) in BW between the LBW and HBW treatments through 32 wk of age. Within each pullet weight class, the HIGH treatment was numerically heaviest through 32 wk. The HBW hens had significantly improved hen-day production from 24 to 28 (P<.001) and 28 to 32 wk (P<.06). The LOW treatment resulted in significantly poorer production in both the LBW and HBW weight groups from 24 to 28 wk. There were no significant treatment effects on egg weight at a given age. Within each pullet treatment, the HIGH treatment resulted in an increased percentage of double yolked (DY) eggs from 24 to 28 wk (P<.05) and 28 to 32 wk (P<.07).In Experiment 2, pullets in each of two pullet treatments received approximately 12 kg of feed from 2 to 24 wk of age. One treatment received a greater quantity of feed early in the rearing period (HEAVY) while pullets in the other treatment received a greater quantity of feed later in the rearing period (LIGHT). One-half of the pullets from each rearing treatment were fed either a 14% (LOWPRO) or 18% (HIGHPRO) protein diet during the prelay period (18 to 24 wk). Pullets in the HEAVY treatment were significantly heavier (P < .01) than those in the LIGHT treatment at 21 but not at 24 wk. The HIGHPRO treatment resulted in a significant improvement (P<.05) in hen-day egg production from 24 to 28 and 28 to 32 wk. There were no treatment effects on egg weight, and the LOWPRO treatment resulted in a significant increase (P≤.01) in the number of DY eggs from 28 to 32 wk.

Effect of Different Protein Levels Fed During the Prebreeder Period on Performance of Turkey Breeder Hens

An experiment was conducted to examine the effects of prebreeder protein intake on subsequent reproductive performance and to examine body weight, feed consumption, and body composition changes due to aging in Large White turkey breeder hens. One hundred twenty-nine Hybrid Large White turkey breeder hens were fed either 12, 15, or 18% CP diets (2,882 kcal ME/kg) during the prebreeder period from 24 to 32 wk of age. All hens were photostimulated with 15.5 h light/day and fed a standard 16% protein breeder ration from 32 to 55 wk of age.Prebreeder protein intake increased linearly as dietary protein increased. Treatments did not affect body weight, body composition, egg production, feed consumption, fertility, hatch of fertile eggs, or percentages of early or late dead. Body weight increased from 24 to 55 wk in a cubic response to age. Percentage of carcass moisture decreased, whereas percentage of carcass fat increased from 24 to 55 wk in a quadratic response to age. Prebreeder and breeder feed consumption were not significantly affected by treatment or age. This experiment is evidence that a 12% protein prebreeder ration is adequate for subsequent reproductive performance; observed effects of age on body characteristics agree with published data.

Effect of Protein and Energy Intake by Broiler Breeders During the Prebreeder Transition Period on Subsequent Reproductive Performance ,

Abstract Two levels of protein and two levels of energy were fed to broiler breeders during the prebreeder period (18 to 23 weeks of age) after which a standard breeder diet was provided to all birds. The differences in intake during the prebreeder period was 140 g protein/bird between the high protein (HP) and low protein (LP) groups and 1145 kcal ME/bird between the high energy (HE) and low energy (LE) groups. Body weights did not differ during the prebreeder period or subsequent breeder period. Cumulative egg production was similar among all treatments with numerical advantages for HP and LE birds due to improved production after 55 weeks of age. Significant protein × energy interactions occurred for egg weight during Weeks 25 to 44, but no significant overall effect was observed. Egg specific gravity was not affected significantly. Fertility did not differ; however, the LP birds exhibited significantly better hatch of fertile eggs and significantly decreased late deads when compared to HP birds. The HE birds exhibited significantly less early embryonic mortality but significantly more late embryonic mortality when compared to LE birds. Hatch of fertile eggs did not differ due to prebreeder energy levels.

Effect of Dietary Protein and Light Restriction on Body Weight and Semen Production of Breeder Male Turkeys

The relationships of dietary protein, body weight gain, prebreeder light restriction, age at the start of semen production, and semen volume were studied. Large White breeder male turkeys were fed corn-soybean meal diets containing the following percentages of protein at different age intervals: Treatment A, 26% (8 to 12 weeks), 19% (13 to 18 weeks), 15% (19 to 52 weeks); Treatment B, 26% (8 to 12 weeks), 19% (13 to 18 weeks), 8% (19 to 52 weeks); Treatment C, 17% (8 to 28 weeks), 8% (29 to 52 weeks); Treatment D, 17% (8 to 18 weeks), 8% (19 to 52 weeks). Body weights at 18, 28, and 52 weeks of age were: Treatment A, 11.8, 20.8, and 21.7 kg; Treatment B, 11.4, 15.1, and 17.8 kg; Treatment C, 9.2, 20.0, and 20.7 kg; Treatment D, 9.1, 11.8, and 15.0 kg. The effects of 6 hr light: 18 hr dark (restricted light) were compared with 12 hr light: 12 hr dark (full light) during the prebreeder period (18 to 28 weeks of age). All turkeys received 14 hr light: 10 hr dark from 29 to 52 weeks of age. With full light, 50% of the turkeys were producing semen at 29 weeks and 100% at 32 weeks. With restricted light, 50% of the turkeys were producing semen at 32 weeks and 100% at 34 weeks. Turkeys fed Treatments A, B, C, and D reached 50% production at 28, 30, 29, and 32 weeks, respectively, and all turkeys were producing semen at 35 weeks. The average semen volume per ejaculate for weeks 34 to 52 were: .35, .34, .34, and .25 ml for Treatments A, B, C, and D, respectively; and .34 and .31 ml for full and restricted light, respectively. Treatments B and D reduced body weight gain after 18 weeks of age. However, Treatment B had better semen production than Treatment D. There was no advantage to restricted light during the prebreeder period.

The Effects of Red and White Light During the Prebreeder and Breeder Periods on Egg Production and Feed Consumption in Large White Turkeys

Large White turkey hens were conditioned with 5 lx of white or red incandescent light from 20 to 32 weeks of age. Hens from both of these groups were given white or red incandescent light at two intensities (approximately 85 and 160 lx) during a 20-week breeder period.Feed consumption was greatest for hens on white light during the prebreeder period (P≤.01), but hens on red light consumed the greatest amount of feed during the breeder period.The only consistent finding concerning egg production was that hens exposed to high intensity (160 lx) white light, regardless of whether the prebreeder light was white or red, had the poorest egg production (P≤.01). It is concluded that red light during the prebreeder or breeder periods is not beneficial for egg production over that achieved with low intensity white incandescent light, and that bright white incandescent light is deleterious to egg production

Influence of Dietary Protein during the Pre-Breeder Period on Subsequent Reproductive Performance of Large White Turkeys: 1. Growth, Feed Consumption, and Female Sex-Limited Reproductive Traits

Large White female turkeys of a commercial variety were used to determine the effects of low dietary protein during the pre-breeder period (12 to 32 weeks of age) on subsequent reproductive performance. Diets containing 10, 12, 14, and 17% protein were fed from 12 weeks or 20 weeks to 32 weeks of age. At 32 weeks of age, all females were fed a 17% protein breeder diet. Reproductive performance was measured for a 24-week production period.Pre-breeder feed consumption and body weight gain from 12 to 32 weeks of age increased with increased dietary protein until diets contained 14% protein. Similar results were obtained when females were fed varying protein levels from 20 to 32 weeks of age.Egg production also showed an increase with increased pre-breeder dietary protein level until diets contained 14% protein. Ten fewer eggs per hen were obtained from females previously fed the 10% protein diet than those fed the 14% (20 to 32 weeks) and 17% protein diets. Pre-breeder dietary protein level did not affect age at sexual maturity, egg weight, specific gravity or shell thickness of eggs, mortality or growth, and feed consumption of progeny.Based upon the results of this study, female breeder turkeys require at least 14% protein to 20 weeks of age and 14% from 20 to 32 weeks of age for optimum egg production.

Influence of Dietary Protein during the Pre-Breeder Period on Subsequent Reproductive Performance of Large White Turkeys: 3. The Effects of Semen Volume and Frequency of Insemination on Fertility and Hatchability

Large White turkey breeders of a commercial variety were used to determine the effects of pre-breeder dietary protein, frequency of insemination, and semen volume on subsequent reproductive performance. Treatments included female dietary protein levels of 10, 12, 14, and 17% fed from 12 to 32 weeks of age and 10, 12, and 14% protein from 20 to 32 weeks of age; male dietary protein levels of 12 and 17% fed from 12 to 56 weeks of age; and artificial insemination (AI) treatments of a) .025 ml of semen at weekly intervals, b) .025 ml of semen at biweekly intervals, and c) .05 ml of semen at biweekly intervals in a factorial arrangement of treatments.Male dietary treatment had no significant effect on fertility or hatchability of fertile eggs. Female pre-breeder protein levels also had no significant effect on fertility but resulted in lower hatchability of fertile eggs during the latter part of the production period when females were fed either the 10 or 12% protein pre-breeder diets.Weekly inseminations with .025 ml of semen resulted in the highest average level of fertility during the production year (90%), followed by biweekly insemination with .05 ml (87%) and .025 ml (85%) of semen, respectively. Hatchability of fertile eggs was significantly higher for hens receiving .05 ml of semen biweekly than for the other two AI treatments during the latter half of the production year only. However, weekly inseminations caused a significant decline (6.7 eggs/hen) in egg production when compared to hens inseminated at biweekly intervals. The average number of fertile eggs was greatest for females inseminated with .05 ml semen biweekly (54.3) compared to those inseminated with .025 ml of semen biweekly (53.0) or .025 ml of semen weekly (50.2).

Influence of Dietary Protein during the Pre-Breeder Period on Subsequent Reproductive Performance of Large White Turkeys: 2. Growth, Feed Consumption, and Male Sex-Limited Reproductive Traits

The effect of low dietary protein during the rearing and breeding periods on the reproductive performance of Large White turkey males was examined. At 12 weeks of age 251 males were randomly divided into two groups and fed either 12 or 17% protein through 56 weeks of age. Body weight gains from 12 to 20 weeks and 20 to 28 weeks of age were significantly reduced for the males receiving the 12% dietary protein. However, after 28 weeks of age, weight differences decreased and by 56 weeks of age body weights of both groups were approximately the same. In addition, a significant reduction in feed consumption was noted for the males fed 12% protein. Males on the high protein diet experienced a higher mortality than those on the low protein diet.Low dietary protein reduced semen volume and spermatozoa concentration at 33 weeks of age, but there were no significant differences thereafter. The percentages of normal, abnormal, or dead spermatozoa were unaffected by dietary protein levels. Feeding 12% protein from 12 to 56 weeks of age to Large White turkey breeder males was adequate for high quality semen production.

Effects of Controlled Feeding of Turkeys during the Pre-Breeder Period on Subsequent Performance

From feeding Large White female turkeys a 16% protein pelleted diet from 22 to 38 weeks of age (1) ad libitum, (2) three days per week, 8 a.m. to 2 p.m. only, and (3) 80% full-fed, body weight gains were 2.72, 1.51 and 1.16 kg, and feed consumptions were 23.19, 20.80, and 18.01 kg, respectively. From feeding male turkeys from 26 to 38 weeks of age according to treatments (1) and (2), body weight gains were 3.73 and .94 kg, and feed consumptions were 34.56 and 25.98 kg, respectively.All turkeys were full-fed mash diets between 38 and 62 weeks of age. During this period, the body weight gains of the three previously treated groups of females were −.51, .48 and .92 kg, feed consumptions were 39.82, 42.25 and 43.01 kg, and percent egg productions were 42.9, 41.1 and 38.2, respectively. Body weight gains of male turkeys from 38 to 42 weeks of age under the previous treatments were −.03 and 2.43 kg, and feed consumptions were 88.84 and 81.01 kg, respectively. Fertility of eggs was significantly better from hens inseminated with semen from males previously full-fed than those previously restricted in feed intake. Restricting feed intake of female and male turkeys during the pre-breeder period provides no specific advantage except for a saving in feed intake especially among males.

Reproduction in Turkey Hens as Influenced by Prebreeder and Breeder Protein Intake and the Environment

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 (El) or a 6-hr. day of 5.4 lx. (E2) in a 2 × 2 factorial design during the prebreeder period of 20 to 32 weeks. Birds of each treatment were randomized into four breeder treatments when lit at 32 weeks. Breeder performance traits were compared where hens were fed either 35 or 50 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 150 lx. (E3). Prebreeder 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 E2/E4 regime significantly increased the age at first egg over the other three environmental combinations. Egg production was significantly reduced by the E2/E4 treatment when compared to E1/E4 and E2/E3. Broodiness was adversely affected by both the E4 and the E2/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.

Effects of Diet and Light During the Pre-Breeder Period, and of Diet During the Breeder Period on Turkey Breeder Performance

Based on two experiments each involving 150 Beltsville or Medium White female turkeys in the pre-breeder period and reduced to 144 in the breeder period, the following results were obtained. When a low energy diet containing 44 percent oat mill feed instead of a currently used high energy diet was fed from 20 to 32 weeks of age, average feed consumption increased 49 percent with only a small decrease in body weight gain. A small reduction in body weight gain was also achieved by feeding the high energy diet on a restricted intake basis saving 10 percent in feed consumption. Fortification of the pre-breeder diet with extra vitamins, and added bacitracin and ethoxyquin failed to influence the results of these measurements, but did tend to increase subsequent egg production (.10 > P > .05). By restricting the amount of light to 6 hours per day during most of the 12-week pre-breeder period of turkey females hatched on October 17, body weights at 32 weeks of age were increased 5.1 percent, feed consumption decreased 12.2 percent, and subsequent egg production was delayed and tended to be increased only slightly (.10 > P > .05). The addition of 6 and 12 percent menhaden fish meal to breeder turkey diets increased hatchability of fertile eggs from 72.4 to 78.7 percent (P < .05) and hatchability of all eggs incubated from 57.3 to 64.6 percent (P < .01); and the addition of extra trace minerals increased fertility of eggs incubated from 78.7 to 83.6 percent (P < .05). Egg production, fertility and hatchability from these hens during the 20-week production periods were not significantly influenced by the energy content of the pre-breeder diets or by adding extra vitamins to the breeder diets in these two experiments.