Effects of light sources and the presence or absence of males on reproduction of female breeder turkeys.

The effects of sodium vapor (SV), daylight fluorescent (DF), and incandescent (IN) light sources and the influence of the presence or absence of males on reproduction of female turkeys were evaluated. Hens under SV and DF lights consistently laid more eggs than those under IN lights. There were no significant differences in hen-day egg production among hens in the physical presence of males and hens allowed visual and vocal contact with males. However, hen-day egg production was significantly lower for females in pens in which males were absent. Fertility, hatchability, days to first egg, egg weight, and egg specific gravity were unaffected by light source treatments or by the presence or absence of males in pens of females.

The effect of light source and intensity on turkey egg production.

The effect of light source and intensity on egg production, fertility, hatchability, egg weight, and shell quality in turkey hens was investigated. Turkey hens were exposed to either incandescent, high-pressure sodium vapor (HPSV), or daylight fluorescent (FL) lights at an intensity of 21.6 1x during the growth phase (after 8 wk). During the breeder phase, hens were assigned to the same light sources at light intensities of either 53.8 or 166.4 1x in a 3 x 3 x 2 factorial arrangement of treatments. Light source during the growth phase had no significant effect on subsequent egg production, egg weight, fertility, or hatchability. Egg production, shell quality, fertility, and hatchability were also unaffected by light source or intensity during the breeder phase. Egg weight was significantly increased in hens exposed to HPSV compared with incandescent lights during the breeder phase. The HPSV and FL lights can be used effectively for turkey breeder hens both during the prebreeder and breeder periods. Furthermore, light intensities of 53.8 and 166.4 1x appear to be equally effective in stimulating production.

Effect of light sources and light intensity on growth performance and behaviour of female turkeys.

1. The effect of different light sources (incandescent, sodium vapour, daylight fluorescent and warm fluorescent) and light intensities (10.8 and 86.1 lux) on growth performance and behaviour of female turkeys was investigated in two experiments conducted at different times of the year. 2. Although light source influenced body weight and efficiency of food utilisation, there was no consistent effect between experiments in favour of any particular source. 3. Light intensity had no effect on body weight, efficiency of food utilisation or behaviour.

Influence of light sources on the growth and reproduction of large white turkeys.

The present study evaluated the effects of sodium vapor (SV), daylight fluorescent (FL) and incandescent (IN) light sources on the growth and reproduction of primary turkeys. Large White turkeys (90 sire line and 324 dam line) were reared by sex under one of the three light sources from 8 to 22 wk of age. At 22 wk of age, all males and females were preconditioned under their assigned light source, but the photophase was restricted to 6 h per day at an intensity of 21.6 lx. At 33 wk of age, the males were exposed to 16 h of light per day under the same light sources in which they were reared. At 35 wk of age, the females were reassigned to the various light sources in order to achieve all possible combinations of adolescent and breeder light-source treatments. Sixteen hours of light per day were provided at an intensity of 53.8 lx during a 20-wk cycle of egg production. The body weights of males and the feed efficiencies of males and females were unaffected by the adolescent light-source treatment. The females were significantly heavier under SV than those under FL and IN lights. Hen-housed egg production was significantly higher for females exposed to SV and FL lights versus IN during the first 10-wk production period. Hen-day egg production was significantly higher for females given FL than for those provided SV and IN lights. However, total hen-housed and hen-day production was unaffected by either adolescent or breeder light-source treatments. Fertility, hatchability, days to first egg, egg weight, and egg specific gravity were also unaffected by either the adolescent or breeder light-source treatment. (ABSTRACT TRUNCATED AT 250 WORDS)

Effect of light sources and light intensity on growth performance and behavior of male turkeys.

This study consisted of two experiments: the first was conducted with Large White turkey males during the spring and summer (experiment 1) and the second during the autumn and winter (experiment 2). When 56 d of age, the birds were assigned to light-controlled pens and exposed to continuous illumination. Light sources used were incandescent, daylight fluorescent, warm fluorescent or high pressure sodium vapour lamps at light intensities of 10.8 or 86.1 lux. Results obtained showed that the light sources used had no significant effects on growth performance, efficiency of food utilization, feather scores or live bird quality of Large White turkeys. Social encounters were higher in birds reared under fluorescent and sodium vapour lights and mortality was higher in birds under fluorescent lights in experiment 1. Behaviour, feather scores, live bird grade and mortality were unaffected by light source treatments in experiment 2. Light intensity had no significant effect on growth, efficiency of food utilization, feather scores or bird market quality. Social encounters and mortality were higher in males exposed to 86.1 lux of light intensity.

Effects of photoperiod and filtered light on growth, reproduction, and mating behavior of turkeys. 1. Growth performance of two lines of males and females.

This study was designed to determine the effects of photoperiod and filtered light on growth of male and female turkeys. Large White (LW) and Medium White (MW) turkeys were reared under intermittent (2 h light: 2 h dark) or diurnal (12 h light: 12 h dark) photoperiods using white light, red (650 nm), or blue (450 nm)-filtered lights. Both males and females grew more rapidly under blue light than under red or white light up to 16 wk of age. After that age, rates of gain were significantly better under the white and red lights. Growth rates were significantly greater under the intermittent than under the diurnal photoperiod for both lines and sexes in Experiment 1 but not in Experiment 2. The greatest acceleration in growth rate was observed from 4 to 10 wk of age, with this advantage still evident at 24 wk of age. No significant differences in feed efficiency due to photoperiod or light color occurred. Early mortality was highest under blue light but late mortality was greater under red and white light. Mortality was higher for the LW than MW birds. Live grades were unaffected by light regimen or light color, but feather condition was poorest for birds reared under the white diurnal photoperiod.

Effects of light environment and population density on growth performance of male turkeys: 2. Physiological changes.

This study was designed to determine the effects of intermittent white light [2 h of light (L) followed by 2 h of dark (D) repeated six times per day] vs. diurnal white, blue, and red light (12L:12D), light intensities of 86.1 lx (high) vs. 5.4 lx (low) at high and low population densities, and season of the year on changes in the pineal, pituitary, and adrenal glands and testes of male turkeys. Pineal gland weights were unaffected by any of the factors under study. Pituitary gland weights significantly increased only in 12-wk-old males reared during the fall and winter compared with those reared during the spring and summer, but were unaffected by the imposed light environments or population density. Adrenal glands were significantly larger in males reared under high population density conditions in comparison with those reared under low density housing. The different light environments were ineffective in altering the effects of population density on adrenal response. Intermittent, high intensity light caused precocious sexual development when males were between 12 and 23 wk of age. White light and red-filtered light stimulated testes activity and seminiferous tubule development, whereas blue-filtered light was nonstimulatory.

Effect of presence or absence of the opposite sex on egg production and semen quality of breeder turkeys.

The effect of the presence or absence of the opposite sex on egg production and semen quality of breeder turkeys was evaluated. Ninety-six female and 36 male Medium White turkeys were used in this study. Two males were released, individually, into each of eight pens of females for 15 min each day, 5 days/wk. Two males in each of four pens of females were physically isolated in wire-enclosed cages in full view of the females. Males assigned to the remaining four pens of females were placed in isolated pens so they were physically, visually, and vocally separated from the females. Egg production was significantly higher for females under natural mating conditions than for females visually exposed to males in holding pens or for females completely isolated from males. Females visually exposed to, but not in contact with males, laid more eggs than those completely isolated from males during the 13th through the 18th week of production. Semen volume and semen concentration was significantly lower, and the percentage normal sperm was higher for males mating naturally than for those maintained in the presence of or completely isolated from females. Semen concentration was highest in isolated males.

Effect of oxytetracycline-hydrochloric acid on reproduction of female turkeys.

Effects of oxytetracycline-HCl on reproductive performance of turkey breeder hens from the 13 to 24-wk production period were evaluated. During the 13th wk of production, females were grouped into low, medium, and high fertility subclasses. Females within each fertility subclass were randomly reassigned to treatments. The antibiotic was administered via the drinking water (T-2) or via the drinking water plus an intravaginal lavage (T-3). Hens receiving T-2 treatment showed significantly higher fertility than untreated controls (T-1) but also showed significantly higher early embryonic mortality than those receiving the T-3 treatment. Hatchability of all egg set was significantly higher in both antibiotic-treated groups than in controls. Females in the fertility subclasses remained significantly different from each other throughout the experiment. To determine the duration of the effect of antibiotic treatment, eggs were collected in a treatment and posttreatment periods. Fertility (P less than .05), and hatchability (P less than .10) were improved during the treatment period compared with results of the posttreatment period. The T-3 treatment had a long-term effect: it maintained early embryonic mortality at 10% and hatchability at the same level during both treatment periods. A short-term effect was observed in the T-2 group; early embryonic mortality increased (P less than .05) and hatchability decreased (P less than .10) during the posttreatment period. No correlations were found between mycoplasmal or bacterial populations and fertility subclass or antibiotic treatment. Egg production, body weight, feed consumption, feed consumed per egg, egg weight, and egg specific gravity were unaffected by antibiotic treatment.

Behavior and growth parameters of large white turkeys as affected by floor space and beak trimming. II. Females.

The effects of floor space allowance and beak trimming on behavior and growth performance of female Large White turkeys were studied. Floor space allowances were 5.6, 7.0, and 9.3 dm2/bird from 0 to 8 weeks of age and 14.0, 18.6, and 23.2 dm2/bird from 8 to 16 weeks of age. Floor space was adjusted by changing pen size to assure a constant number of birds per pen. Results showed that neither floor space allowance nor beak trimming had any significant effect of any of the variables under study through 8 weeks of age. At 16 weeks of age, growth, feed consumption, feed efficiency, feather scores, live market quality grades, and mortality were still unaffected. Beak trimming significantly reduced body weight gain, body weight, and feed consumption but had no significant effect on feed efficiency, feather scores, or mortality. Agonistic (aggressive) behavior was very low in this population of females. Of significance, however, were the nonaggressive behaviors of social "pecking" and "pecking and pulling" of feathers. Feather-pecking activity was unaffected by previous or subsequent floor space allowances through 16 weeks of age; however, the incidence of pecking and pulling of feathers was highest among females previously assigned the largest floor space allowance (9.3 dm2/bird) in the brooder house and subsequently allowed the smallest floor space allowance (14.0 dm2/bird) in the grower house. Beak trimming significantly increased the frequency of both "pecking" and "pecking and pulling" of feathers over that of their untrimmed contemporaries when the females were 12 and 16 weeks of age. Possible reasons for this are discussed.

Effects of light environment and population density on growth performance of male turkeys.

This study was designed to determine the effects of various light environments on the growth performance of male turkeys reared under two extremes of population density. Environmental lighting had subtle but persistent effects on growth performance. Low-intensity illumination consistently improved body weight gains during early growth periods while high-intensity illumination improved body weight gains during the later growth period. Intermittent lighting, especially at a light intensity of 86.1 1x, caused precocious sexual development and appeared to stimulate growth after 18 weeks of age during cool weather and after 12 weeks during warmer weather. Diurnal, blue-filtered light improved weight gains during early growth periods compared to either white- or red-filtered diurnal light, while white- or red-filtered light tended to improve weight gains during the later growth period. Floor space allowances studied had no significant effect on growth or feed efficiency prior to 12 weeks of age. At that time, high population density caused lower body weight gains, lower feed efficiency, poorer feathering, a higher incidence of downgrading, and higher mortality than did a relatively low population density. Different light environments [intermittent (2L:2D) white light and diurnal (12L:12D), white-, red-, or blue-filtered light] were ineffective in altering the responses of turkeys to crowding. There was, however, a significant interaction of light intensity with population density. This interaction indicated that high light intensity allowed maximum expression of growth potential in a low population density environment but reduced growth under high population density pressures.

Effect of dietary calcium on blood pressure of turkeys.

The influence of dietary calcium intake on blood pressure of turkeys was studied in 20 male Broad Breasted White turkeys between 45 and 52 weeks of age. The average systolic (P less than .01), diastolic (P less than .01), and mean (P less than .005) blood pressures were significantly lower in turkeys fed high dietary calcium (1.96%) than the turkeys with normal calcium diet (.98%). Concomitantly, the mean total heart weight (P less than .05), left ventricular weight (P less than .025), and heterophil to lymphocyte ratio (P less than .02) were also significantly lower in the high dietary calcium group. These results indicate that high dietary calcium not only attenuates high blood pressure in turkeys but also reduces the development of left ventricular hypertrophy, which is a consequence of arterial hypertension. In addition, high dietary calcium also reduces the heterophil to lymphocyte ratio, which indicates a reduction of stress.

Effect of light environment during the adolescent period on subsequent semen volume and concentration of male turkeys.

One hundred eighty males were utilized in two field-type experiments. In one experiment, light was restricted to 6 or 12 hr of light per day at a light intensity of 10.76 1x from 12 through 28 weeks of age. In the second experiment, one flock was maintained under natural light while the other was maintained under 12-hr lights and 10.76 1x of light intensity from 12 to 31 weeks of age. All flocks were placed under a 14-hr light day and a light intensity of 32.3 1x in light-controlled houses during the breeding season. Results obtained in the first experiment showed an increase in semen volume from the first to the fourth observation period and then a decline in both flocks during the last period. Average semen volume over the entire experimental period was unaffected by light treatment during the adolescent period. Semen concentration was highest during the early part of the breeding season and gradually declined as the season progressed. Males under a 6-hr restricted light regimen during the rearing period produced an average of .6 billion more sperm cells per milliliter than did those reared under 12 hr of light per day (P less than or equal to .01). Results obtained in the second experiment showed an average semen volume throughout the breeding season of .24 and .19 ml and a semen concentration of 7.0 and 6.4 billion sperm cells per milliliter for males reared under natural light compared to those reared under 12-hr lights, respectively . These differences were significant (P less than or equal to .01). Data were subjected to polynomial analyses.(ABSTRACT TRUNCATED AT 250 WORDS)

Behavior and growth parameters of large white turkeys as affected by floor space and beak trimming. 1. Males.

The effects of floor space and beak trimming on behavior and growth of Large White male turkeys were investigated Floor space allowances were 6.5, 9.3, and 12.1 dm2/bird at 0 to 8 weeks; 11.7, 16.7, and 21.8 dm3/bird at 8 to 12 weeks; and 28, 35, and 42 dm3/bird at 12 to 20 weeks. Floor space was adjusted by changing the pen size while maintaining a constant number of birds per pen. Body weight, feed intake, feed efficiency, feather score, live market quality, and mortality were measured. In addition, agonistic behavior including "threat avoids", "peck avoids", "threat chases", "peck chases" and "fights", and nonagonistic behavior including feather "pecks" and "pecks and pulls" were determined at 12 and 20 weeks of age. Floor space had no significant effect on any parameter measured through 8 weeks. At 12 weeks, feed efficiency and body weight were significantly decreased with decreasing floor space. By 20 weeks, the body weight of the birds grown at the intermediate floor space allowance from 8 to 12 weeks was no longer significantly different from those grown at the highest floor space allowance; however, the birds grown at the highest density from 8 to 12 weeks remained significantly lighter at 20 weeks. Compensatory growth, if present, appeared limited. Beak trimming had no significant effect on body weight or feed efficiency. Food intake was significantly greater in the beak trimmed birds from 12 to 18, but there was no significant difference from 12 to 20 weeks. From 12 to 20 weeks, mortality was significantly less in beak-trimmed birds.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood proteins and amino acids of female breeder turkeys fed on maize-soybean diets supplemented with methionine.

Two hundred and six female breeder turkeys were fed on maize-soybean diets of equal energy content, containing 100, 120 or 140 g crude protein (CP)/kg to which DL-methionine was added at 0, 1, 2 or 3 g/kg diet in a factorial design. Serum albumin concentrations were found to be more sensitive measures of dietary protein adequacy than were total serum protein concentrations. Albumin concentrations at peak egg production were highest among birds fed on 120 and 140 g CP/kg diets. Four weeks later, they were highest only for those on the 140 g CP/kg diet. The elevated concentrations of blood threonine and lysine and the decreased concentration of glycine with increased dietary protein were in agreement with the data on egg production. These data suggested that a sub-optimal balance of dietary amino acids may have occurred.

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. 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.

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, an 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).

A study of certain environmental factors and mineral chelation on the reproductive performance of young and yearling turkey hens.

The study presented was designed to determine the effects of laying cages and conventional litter floors, pen temperatures of 12.8 degrees, 21.1 degrees and 29.4 degrees C., and chelated (EDTA-Zn) vs. nonchelated trace mineral mixes on the reproductive performance of yearling force-molted and young Large White female turkeys. Reproductive performance, as measured by egg production, settable eggs, fertility and hatchability of fertile eggs, was not significantly different between young and yearling hens. Females fed a chelated trace mineral mix had a higher percentage of settable eggs, greater feed consumption and thicker egg shells. Females in laying cages laid at a higher rate, ate more feed, and weighed more than those on conventional floors. Significant differences were not observed between the two pen environments for hatchability of fertile eggs or egg weight. The percentages of settable eggs and of fertile eggs were lower when females were maintained in cages. A constant temperature of 29.4 degrees C. reduced egg production below that obtained from females maintained at 12.8 degrees and 21.1 degrees C. The high pen temperature also caused lower body and egg weights, more birds out of production and an increased incidence of molting. Feed consumption decreased with increasing pen temperatures. Fertility, hatchability, percentage of settable eggs and egg shell thickness were unaffected by the imposed temperature environments. Temperatures of 12.8 degrees and 21.1 degrees C. yielded comparable results for all reproductive parameters measured. Within the range of temperatures studied, results obtained suggest that optimum reproductive performance can be obtained with breeder turkeys when environmental temperatures are maintained between 12.8 degrees and 21.1 degrees C.