This study was carried out to investigate the effect of dietary lipid sources and meal frequency on growing performance and lipid metabolism in Sprague-Dawley strain male rats. The expreriment was conducted in 4×2 factorial arrangement with 4
sources
of dietary lipid(palm oil, beef tallow, soybean oil and hydrogenate soyben oil) and 2 meal frequencies (ad-libitum or meal feeding). During the 4-week feeding period the rats were fed either ad-libitum(AL) or a signle daily 3-hour meal(09 : 00-12
:
00)
during the dark period. In vitro cultures were carried out the study the cholesterol synthetic activity in the ,liver prepared from rats used in feeding trials. And in vitro cultures were also carried out to study the lipogenic and lipolytic
activity in
the liver and adipose tissues prepared from rats used in feeding trials.
Present data indicated that body weight gain, feed intake and FER of AS(ad-libitum+soybean oil) and AHS(ad-libiitum+ hydrogenated soybean oil) group were significantly(p<0.05) higher than those of the other groups. It was found that the feed
intake
of
MF group was much less than that of AL group. Total body weight gained by MF group was only 60% of AL group. Growing performance was not affected by dietary lipid sources.
The cholesterol synthetic activity in liver tissues culture was warkedly(p<0.05) in creased in MF diets, especially in soybean oil group.
The lipogenic activity in liver tissues culture of MP(meal feeding+palm oil) and MHS (meal feeding+hydrogenated soybean oil) group was significantly(p<0.05) higher than that of AP(adlibitum+palm oil) group and AHS(ad-libitum+ hydrogenated soybean
oil)
group (p<0.05). rats fed ad-libitum+beef tallow and fed meal feeding+beef tallow showed significantly(p<0.05) higher lipogenesis than the other groups. It was apparent that the lipogenic activity in liver tissues culture was not affected by
dietary
lipid sources and meal frequency. Lipolytic activity in live tissue culture was sign
ificantly(p<0.001) different with meal frequency; MF group was higher than AL group, but was not greatly affected by dietary lipid sources.
In the in vitro studies with adipose tissue, MF diets increased the lipogenic activity and inhibited the lipolytic activity in adipocytes. The lipogenic activity in adipocytes was significantly (p<0.001) different with dietary lipid sources and
found to
be beef tallow group was the highest, but the sources of lipid in the diet did not exert any effect on the lipolytic activity.
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