The objectives of this thesis were to determine the
nutritive value and digestibility of head lettuce (Lactuca
sativa) residue and Mimosa pigra compared to water
spinach (Ipomoea aquatica) and Ruzi grass (Brachiaria
ruziziensis) as feeds for rabbits and the effect of feeding
these forages on the performance of growing rabbits on-station as
well as on-farm.
The objectives of the study on-station were to compare
the effect of four kind of forages, two breeds (New Zealand White
and crossbred New Zealand White x native breed) and sex on feed
intake, growth performance and digestibility in rabbits, offered a
basal diet of a commercial concentrate at a level of 2% dry matter
(DM) of body weight (BW). The results showed that the rabbits fed
Mimosa pigra had significantly higher DM intake than the
rabbits fed head lettuce residue, Ruzi grass and water spinach, 96
g, 81 g, 70 g and 66 g DM/day, respectively. The rabbits fed Ruzi
grass had a poor growth rate, 14.8 g/day, which was significantly
different from the rabbits fed head lettuce residue, water spinach
and Mimosa pigra, 17.6 g, 18.4 g and 18.5 g/day,
respectively. Pure breed rabbits had significantly higher live
weight gain than crossbred rabbits, 18.0 g and 16.7 g/day,
respectively. There were no significant differences due to sex.
Digestibility coefficients were similar for the two breeds but the
foliages had a significant effect on the digestibility coefficients
of all nutrients. The rabbits fed water spinach and head lettuce
residue had significantly higher digestibility of nutrients than
rabbits fed Mimosa pigra or Ruzi grass. The native rabbits
digested the fiber better than the New Zealand White
rabbits.
In the on-farm study the effect of feeding head lettuce residue
and Mimosa pigra on growth performance of rabbits and the
costs of these diets compared to feeding Ruzi grass was studied. A
commercial concentrate offered at 2% DM of BW was the basal diet.
Rabbits fed the head lettuce residue and Mimosa pigra diets
had significantly higher growth rate and feed intake than those fed
the Ruzi grass diet. Feed conversion ratio for the Mimosa
pigra diet was highest compared to Ruzi grass and head lettuce
residue, 5.2 g, 4.9 g and 4.6 g DM/g weight gain, respectively.
Economic analysis showed that the costs for the head lettuce
residue and Mimosa pigra diets were higher than for the Ruzi
grass diet but the net profit per kg BW of the rabbits fed Ruzi grass was lowest compared to Mimosa
pigra and head lettuce residue diets, 36 Baht, 39 Baht and 40
Baht/kg BW, respectively.
The results from these two studies confirm that feeding
head lettuce residue and Mimosa pigra to rabbits improved
growth performance and gave a better net profit than Ruzi grass.