PHASE FEEDING IN FATTENING RABBITS

In this study two points were tried to be solved, the first was the effect
of phase feeding successive diets, differing in calorie / protein ratio,
on fattening performance and digestibility . The second point was the
value of using high energy diets while maintaining the crude fiber at
its high level. Two experiments were performed in this study, the first
was the growth experiment and the second was the digestibility one .In
experiment I, seven groups each of 12 weaned New Zealand White
rabbits were fed according to different seven feeding regimens , three
of them(group I , group IV and group VII) followed single feed
program and fed diets 1 (2500 & 17) , 4 (2700 & 18.5 ) , and 7 (2900
kcal ,DE /kg & 19.5 % CP ) while the other four groups followed the
three - phase feeding system (4 – 7 , 7-10 ,and 10 – 12 weeks of age )
and fed on diets with 2500 kcal / kg & CP % from 20 descending to 14
(group II ) and from 14 ascending to 20 ( group III ) and diets with
2700 kcal/kg with CP % from 21.5 to 15.5 ( group V ) and from 15.5
to 21.5 %(group VI). In experiment II , the digestibility of the different
diets in the three phase periods was determined where 4 rabbits were
borrowed at time from its respective group .Results revealed that the
feasibility of feeding high energy – high protein diets to fattening
rabbits . As feed conversion efficiency was linearly improved by
increasing energy and crude protein , the DE and CP were efficiently
used in growth as it was clear from the figures for kcal /gain : 7.75 &
9.91 vs. 10.56 and protein efficiency ratios :1.92 &1.47 vs. 1.39 for
2900 & 19.5 -, 2700 &18.5 - versus 2500 kcal, DE/kg & 17% CP -diets, respectively . The digestibility of dry matter, crude protein, and
ether extract of diet 7 was significantly higher than that of diet 1.
Comparing the single feed system with the suggested phase feeding
systems indicated that beginning of fattening period on high energy
and high protein – diet ( 2700 kcal, DE/kg & 21.5 % CP ) with
reducing the protein level, as rabbits grew, to 18.5 and then to 15.5 %
led to the most efficient fattening performance . The cost of 1 kg gain
was the final judgment . There was reduction in production cost with
the suggested feeding regimes to be tested below the recommended
control one .The highest cost/kg gain (about 6.4 L.E.) was recorded by
group I and group IV (to some extent) while the least cost (5.03) was
recorded by group V with savings of about 21 % . The production cost
of group II and group VI was in between. Although group V had the
least cost, it was not distinctly different from group VII and group III.
In conclusion, we recommend the three diets-system of group V to be
applied or the feeding system under which group III was raised when
the price of oil is high or uneconomical to be added.