RESUMEN
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.
Asunto(s)
Peso Corporal , Luz , Periodicidad , Pavos/crecimiento & desarrollo , Animales , Femenino , MasculinoRESUMEN
An experiment was undertaken to study the effect of exposing incubating embryos to short ultrasonic pulses across the intact egg shell. Three minute exposures to 2.25 MHz. pulses, average incident intensity equals 28.6 mW./cm.2, failed to show any effect on embryonic mutation, hatchability, sex ratio, or body weight. On the average the ultrasonic absorption of the egg shells ranged from 26 dB./mm. at 0.6 MHz. to 100 dB./mm. at 2.25 MHz. The transmitted power incident on the blastodisc, consisting mainly of spectrum components below 1.0 MHz., was estimated at congruent to 1% of the incident power.
