| dc.description.abstract | Three experiments were carried out to
evaluate the effect of dietary calorie:protein
(C:P) ratio and diammonium citrate (DAC) on
abdominal fat content and performance in broiler
chickens. In Experiment one, a narrow C:P ratio
diet was fed to four groups of day old broiler
chicks for the first one, two, four or six weeks
of age, fol lowed by feeding a wide C:P ratio diet
up to eight weeks of age. In Experiment two,
chicks were fed on a pre-experimental commercial
starter diet up to four weeks of age. At the
start of the fifth week, they were randomly put
under four dietary treatments consisting of
feeding an experimental narrow C:P ratio diet for
0, 1, 2 or 3 weeks, followed by a commercial wide
C:P ratio diet up to the eighth week of age. In
Experiment three, a narrow C:P ratio diet was fed
to all the chicks up to four weeks of age. From
the fifth to the eighth week of age, the chicks
were randomly put under four dietary treatments
comprising:- i) a narrow C:P ratio diet containing
intact protein ii) a similar diet but with an
equivalent of 4% protein replaced by DAC iii) a
wide C:P ratio diet containing intact protein
iv) a similar wide C:P ratio diet but with an
equivalent of 4% protein replaced by DAC.
xiv
Results at eight weeks of age showed that
chicks that were fed on narrow C:P ratio diets
for the shortest duration gave higher (P)0.05)
abdominal fat than where such duration was
prolonged. Mean abdominal fat pad weights were
42.52 g, 17.64 g and 41.93 g in Experiments one,
two and three respectively. No differences
(P)0.05) occurred between the sexes.
There were no differences (P)0.05) in body
weight and feed efficiency in Experiment one.
Chicks that were fed on a wide C:P ratio diet for
the longest duration in Experiment two gave a
lower (P<0.05) body weight and poorer (P<O.OS)
feed conversion efficiency. Chicks that received
a narrow C:P ratio diet (without DAC) up to eight
weeks of age in Experiment three gave a higher
(P<0.05) mean body weight (2043 g), the highest in
the study. Mean body weights attained in
Experiments one, two and three were 1648 g, 1433 g
and 1835 g respectively. No differences (P)0.05)
occurred in feed intake in any of the three
experiments. Males were on the whole heavier than
females.
Diammonium citrate (DAC) was close to intact
protein in reducing fat level in the narrow C:P
ratio diet but inferior in promoting weight gain.
A similar comparison in the wide C:P ratio diets
showed that DAC failed to reduce abdominal fat
but effectively supported growth.
High protein intake from prolonged
consumption of the narrow C:P ratio diets may have
caused a relative shortage of carbohydrate in the
body and increased heat increment from metabolism
of excess protein, consequently reducing
lipogenesis. DAC might have been utilised to form
dispensable amino acids whose metabolism
effectively decreased lipogenesis in the high
protein diet, supported weight gain in the low
protein diet and depressed feed intake in both
diets. | en |
