24748
document
Phytase and 1alpha-hydroxycholecalciferol supplementation of broiler chickens during the starting and growing/finishing phases . Supplemental 1alpha-hydroxycholecalciferol ( 1alpha-OHD3 ) has been shown to have qualitatively similar and quantitatively additive effects to exogenous phytase . Two experiments were conducted from 0 to 35 d in floor pens to determine the additive effect of phytase and 1alpha-OHD3 when supplemented to Ca- and P-deficient diets . In both experiments , at least 4 replicates per treatment ( 50 chicks per replicate ) were used . Corn-soybean-meal-and soybean-oil-based diets were fed and birds were raised in a house impervious to ultraviolet light . During the starter phase ( ST ) , from 0 to 18 d , chicks were fed a 23 % CP diet containing 0.60 % Ca and 0.47 % total P ( tP ) . During the grower/finisher phase ( GF ) , from 19 to 35 d , birds were fed a 19 % CP diet containing 0.30 % Ca and 0.37 % tP . A combination of 1,000 phytase units/kg of Natuphos phytase and 5 microg/kg of 1alpha-OHD3 ( P+1A ) was supplemented to some of the feed during the ST and GF . Diets containing adequate Ca and P were also fed during the ST ( 0.90 % Ca , 0.68 % tP ) and GF ( 0.80 % Ca , 0.67 % tP ) . Performance characteristics and the incidence of rickets and tibial dyschondroplasia were measured at 18 and 35 d. In experiment 1 , unsupplemented chicks performed well but had considerable leg problems . Chicks fed P+1A during the ST or GF did not perform as well as birds fed P+1A throughout . Birds fed P+1A throughout performed as well birds fed the adequate diets without any indication of leg problems . In experiment 2 , unsupplemented birds performed similarly to unsupplemented birds in experiment 1 . However , chicks fed the supplements or the control diets did not perform as well or accumulate as much bone ash as birds in experiment 1 , although the diets were formulated identically in both experiments . Diets with as little as 0.30 % Ca and 0.37 % tP appear to be adequate for broilers older than 18 d if supplemented with the correct amounts of phytase and 1alpha-OHD3 . However , there are unknown variables that may limit the potential of broilers in terms of bone mineralization and bone pathology , even when adequate diets are fed .
24749
Intervention_Pharmacological
Phytase
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Intervention_Pharmacological
1alpha-hydroxycholecalciferol supplementation
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Intervention_Pharmacological
phytase
24752
Intervention_Pharmacological
1alpha-OHD3
24753
Intervention_Pharmacological
Ca- and P-deficient diets
24754
Intervention_Other
a house impervious to ultraviolet light
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Outcome_Physical
Performance characteristics
24756
Outcome_Physical
incidence of rickets and tibial dyschondroplasia
24757
Outcome_Physical
leg problems
24758
Outcome_Physical
accumulate as much bone ash
24759
Outcome_Physical
bone mineralization
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Outcome_Physical
bone pathology
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Participant_Condition
broiler chickens
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Participant_Condition
at least
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Participant_Condition
) were used . Corn-soybean-meal-and soybean-oil-based diets
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Participant_Condition
house impervious to ultraviolet light
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Participant_Condition
birds
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Participant_Condition
birds