| Summary: | 碩士 === 東海大學 === 畜產學研究所 === 84 === The objects of the study were to investigate (1) whether
fatsource and age of chicks affecting the efficacy of lecithin
inimproving the digestibility of fat in broilers and (2)
themetabolizable energy value of lecithin. Experiment 1, one
hundred and twenty 3-d old Arbor Acres chickswere allotted to a
2×2 factorial design arrangement. Chicks werefed diets
supplemented with 8% of soybean oil or tallow and 0 or2% of
lecithin. Lecithin was supplemented by replacing starch ofthe
diets. And 0.25% Cr2O3 was added in diet as an indicator.There
were six replicates each treatment with five chicks
eachreplicate. Chicks were fed in a heated wire-floored
metabolismcage; excreta were collected for 5d each starting from
age 7 and21 d. The results indicated that the digestibility of
soybean oilwas higher than the digestibility of tallow (P<
0.01). Elderchicks had a higher fat digestibility than younger
chicks had (P <0.01). Adding lecithin to diets improved fat
digestibility (P <0.06). There were no interaction between fat
source×lecithin andbetween lecithin×age (P > 0.05). The
digestibility of fatty acidsin soybean oil was higher than the
fatty acids in tallow (C16:0,C18:0, C18:2 and C18:3: P < 0.01;
C18:1: P < 0.05). Elder chickshad a higher individual fatty acid
digestibility than youngerchicks had (C16:0, C18:0, C18:1, C18:2
and C18:3: P < 0.01).Adding lecithin to diets could improve
C16:0 and C18:0digestibility (P < 0.01). But not the
digestibility of C18:1,C18:2 and C18:3 (P > 0.05). Experiment
2, one hundred and twenty 8-d old Arbor Acres chickswere
allotted to four treatments and were fed one of four corn-
SBMdiets: (1) Diet 1, containing 20% glucose; (2) Diet 2,
containing15% glucose and 5% lecithin; (3) Diet 3, containing
10% glucoseand 10% lecithin; (4) Diet 4, containing 20%
lecithin. And 0.25%Cr2O3 was added in diet as an indicator.
There were six replicateseach treatment with five chicks each
replicate. Chicks were fed ina heated wire-floored metabolism
cage; excreta were collected from14 to 21-d old. The
metabolizable value of lecithin was determinedby extrapolating
lecithin to 100% of diet according to the linearregression
between the metabolizable energy of diets and thelecithin
contents. The determined metabolizable energy of lecithinwas
6147 kcal/kg.
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