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Titolo:
Effects of light intensity from photostimulation in four strains of commercial egg layers: 2. Egg production parameters
Autore:
Renema, RA; Robinson, FE; Feddes, JJR; Fasenko, GM; Zuidhof, MJ;
Indirizzi:
Univ Alberta, Dept Agr Food & Nutr Sci, Edmonton, AB T6G 2P5, Canada Univ Alberta Edmonton AB Canada T6G 2P5 Sci, Edmonton, AB T6G 2P5, Canada Alberta Dept Agr, Food & Rural Dev, Edmonton, AB T6H 5T6, Canada Alberta Dept Agr Edmonton AB Canada T6H 5T6 Edmonton, AB T6H 5T6, Canada
Titolo Testata:
POULTRY SCIENCE
fascicolo: 8, volume: 80, anno: 2001,
pagine: 1121 - 1131
SICI:
0032-5791(200108)80:8<1121:EOLIFP>2.0.ZU;2-1
Fonte:
ISI
Lingua:
ENG
Soggetto:
BROILER BREEDER HENS; FEED ALLOCATION; OVIPOSITION TIME; DOMESTIC-FOWL; DARK CYCLES; BODY-WEIGHT; LAYING HEN; DAY LENGTH; PULLETS; PHOTOREFRACTORINESS;
Keywords:
egg layer strain; egg production; sequence length; egg weight; light intensity;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
34
Recensione:
Indirizzi per estratti:
Indirizzo: Robinson, FE Univ Alberta, Dept Agr Food & Nutr Sci, Edmonton, AB T6G 2P5,Canada Univ Alberta Edmonton AB Canada T6G 2P5 , AB T6G 2P5, Canada
Citazione:
R.A. Renema et al., "Effects of light intensity from photostimulation in four strains of commercial egg layers: 2. Egg production parameters", POULTRY SCI, 80(8), 2001, pp. 1121-1131

Abstract

The effects of light intensity (LI) from photostimulation to 45 wk of age on egg production parameters and egg size characteristics were examined in four layer strains. Floor housed pullets were raised in a light-tight facility from 1 d of age until housing in individually illuminated cages at 17 wk of age. At 17 wk of age, two white egg strains, ISA-White (ISA-W) and Shaver 2000 (S2000), and two brown egg strains, ISA-Brown (ISA-B) and Shaver 579 (S579), were assigned to a processing group [Group 1 was killed at sexual maturity (first oviposition); Group 2 was kept to 45 wk] and were photostimulated at 18 wk of age using a LI of 1, 5, 50, or 500 lx (4 x 4 factorialdesign). One bird from Group 1 and one bird Group 2 were caged together inindividually lit cages (one brown and one white egg layer). Cages were equipped with hardware to monitor egg laying time. Data of individual egg weight and time of lay were kept on Group 2 birds until 45 wk of age. Egg production data were analyzed for hen-day production, laying sequence length, egg and egg component weights, time of lay, and egg interval time as related to strain or LI. Hen-day production was greater in brown egg strains (ISA-B = 86.7%, S579 =88.1%) than in white egg strains (ISA-W = 83.4%, S2000 = 82.3%) and was reduced in birds under 1 Ix compared to 5 or 50 Ix. A LI of 1 lx resulted in reduced egg production and laying sequence length compared to birds with a 50 or 500 Ix. The effects of LI were strain dependant, however. Postpeak sequence length and egg production declined at more rapidly under 500 lx compared to other LI in brown egg strains, indicating possible development of aphotorefractory condition. Mean settable egg weight was lower in 500 lx birds (56.1 g) compared to other groups (mean = 57.9 g), reducing total egg mass produced. Mean interval between successive eggs in a sequence was lengthened in 1 Ix birds compared to other LI groups. Mean time of lay was earlier in brown egg strains than in white egg strains by 48 min. Mean time of lay was shifted to occur later by an increasing Ll. Light intensity affected sexual maturation and egg production, as layers had differential responses to lighting. LI of 1 Lx and 500 lx were found to be limiting to the egg production efficiency of layers. Whereas the birds receiving 1 Lx had a reduced rate of egg production, those receiving 500 lx had reduced egg size later in the production period in combination with reduced shell quality, which indicated that inadequate feed intake under high LI conditions may be a factor affecting layer stocks. Exposure to high LI reduced egg size and total egg mass produced. Ultimately, the brown egg strains appeared to be more susceptible to the negative effects of low or high LI, indicating the importance of matching management practices to the particular hen genotype.

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Documento generato il 05/12/20 alle ore 14:08:29