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Titolo:
Effect of intermittent light regimens on the performance of intact male turkeys
Autore:
Lewis, PD; Perry, GC; Sherwin, CM;
Indirizzi:
Univ Bristol, Dept Vet Clin Sci, Bristol BS18 7DU, Avon, England Univ Bristol Bristol Avon England BS18 7DU ristol BS18 7DU, Avon, England
Titolo Testata:
ANIMAL SCIENCE
, volume: 67, anno: 1998,
parte:, 3
pagine: 627 - 636
SICI:
1357-7298(199812)67:<627:EOILRO>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
LARGE WHITE TURKEYS; POPULATION-DENSITY; GROWTH-PERFORMANCE; ENVIRONMENTAL-CONDITIONS; LEG ABNORMALITIES; BEHAVIOR; BROILERS; SPACE; DIET;
Keywords:
behaviour; light regime; performance; photoperiod; turkeys;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
38
Recensione:
Indirizzi per estratti:
Indirizzo: Lewis, PD Univ Bristol, Dept Vet Clin Sci, Bristol BS18 7DU, Avon, EnglandUniv Bristol Bristol Avon England BS18 7DU 8 7DU, Avon, England
Citazione:
P.D. Lewis et al., "Effect of intermittent light regimens on the performance of intact male turkeys", ANIM SCI, 67, 1998, pp. 627-636

Abstract

An 8-h photoperiod, compared with 12-, 16- or 23-h photoperiods, has been shown to reduce the incidence of injurious pecking and leg problems in intact male turkeys but to result in lower body weights, slower sexual development and less efficient food conversion. The effect of 8 h of illumination given as a solid photoperiod, as eight 1-h periods equally spread through the 24 h or concentrated into a 12-h part of the day on the performance of BUT 8 intact male turkeys was investigated. Fragmentation of the daily illumination increased body weight, improved food conversion efficiency but did not significantly affect food intake. Increased sexual displaying and significantly better food conversion between 16and 20 weeks by the two intermittently illuminated groups strongly Suggested that both regimens were interpreted as stimulatory daylengths. Generally, losses due to mortality and culling were higher in both fragmented groups, while injurious pecking was higher in 8(1L :2D) birds before 5 weeks and in birds given a 12-h 'subjective day' after 5 weeks than in 8-h controls. Gulling due to leg problems Tons significantly higher in birds on the 8(1L:2D) regimen but the incidence of leg imperfections was minimal (< 0.037) inall groups. Both intermittent groups but the 8(1L:2D) in particular, showed a reduced response to hand movement across the eyes compared with 8-h controls. The controls ate proportionately more food during their 16-h dark period than did the intermittent group during their 12-h 'subjective night', though both groups increased their 'nocturnal' feeding with age.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 24/09/20 alle ore 21:28:42