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MEKARN Workshop 2008: Organic rabbit production from forages |
One strategy to improve raising rabbit is utilizing non-conventional feed sources like Azolla microphylla, so that feed cost could be depressed. Azolla microphylla is one species from the genus Azolla, could participate in the symbiotic fixation of atmospheric N2 with Anabaena azollae resulting on high protein content. Therefore, azolla could be used as protein source in rabbit’s ration beside increasing the soil fertility. Utilization of azolla in rabbit’s ration should be mix with fiber source feedstuff, for example rice bran.
A case study in Semarang, Indonesia, feeding 360-400 g/head/day of ration containing 90% fresh azolla mix with 5% rice bran and 5% tofu waste for 2 weeks showing stable performance/libido, no diarrhea occurrence (in young rabbit), better growth and no kit mortality (in suckling kits), however, in pregnant rabbit resulting on abortion three days before partus. The ration is high palatable and also cheap in price (Rp.125,-/head/day).
Introduction
The increasing cost of imported feed ingredients has prompted animal nutritionists and feed processors to focus their attention on non-conventional feed sources. Earlier studies indicates that expensive and imported feedstuff can be substituted with local feedstuff containing high protein in example Azolla microphylla.
Rabbit needs ration with high fiber content. The fiber content of Azolla microphylla is relatively high. Therefore, beside as protein source, Azolla microphylla could also be used as fiber source at the same time in rabbit’s ration. As herbivorous animal, rabbit is capable in utilizing nutrient in the ration through cecotrophy (Rahardjo et al 1990, Rahardjo 2005). Several researches havebeen done especially on the utilization of Azolla microphylla as protein source in rabbit ration. It was used by mixing it with other fiber source feedstuffs like tofu, and rice bran. The results of utilizing azolla as non-conventional protein source for rabbit’s ration in Semarang is presented on this paper.
Azolla is a genus of small aquatic fern that is found in the temperate and tropical regions of the world. It was derived from the Greek words azo (to dry) and ollyo (to kill), meaning ‘when it dries it dies’. Azolla microphylla Kaulfuss belong to genus Azolla and subgenus Euazolla. In shallow water the plant roots attach to the soil and absorb nutrients from the soil (Quebral 1989).
Azolla can certainly coexist favorably with paddy rice. Most significantly, since azolla can directly utilize nitrogen from the atmosphere through its association with the blue-green alga, Anabaena azollae. It can therefore add more nutrients to the soil, specifically nitrogen, much more than what it can actually take from the soil. The average of N-fixation of azolla ranges from 0.4 kg to as much as 2.9 kg N/ha/day when grown together with rice plants (Badayos 1989).
Normally the fresh weight of the mass of azolla, when the surface is completely covered by a single layer at 16 days, is around 15-20 tons/ha under Philippine conditions (Quebral 1989). Production of fresh Azolla microphylla in Semarang (Indonesia) at single harvest of 2 weeks is around 9-12 tons/ha (Ristiarso 2008 per.com). The proximate analysis, trace mineral composition, and cell wall components of Azolla microphylla, dry matter (DM) basis in average of five sampling are given in Table 1 and Table 2, respectively (Querubin et al. 1989).
| Table 1: Proximate analysis, and trace mineral composition of Azolla microphylla | |
|
Constituent |
% DM |
|
Crude protein |
23.7 |
|
Ether extract |
2.93 |
|
Crude fiber |
15.0 |
|
Ash |
28.7 |
|
NFE |
31.1 |
|
Calsium |
2.07 |
|
Total phosphorus |
0.77 |
|
Non-Protein Nitrogen |
0.99 |
|
Iron |
0.25 |
|
Manganese |
0.27 |
|
Magnesium |
0.17 |
|
Sodium |
0.49 |
|
Potassium |
4.93 |
|
Copper, ppm |
17.6 |
|
Zinc, ppm |
71.8 |
| Source: Querubin et al. (1989). | |
With such high protein levels and high in trace minerals (Table 1), Azolla microphyla may be considered a rich nutrition source of feed for livestock. The azolla was high also in fiber content (Table 2). Furthermore, lignin and silica were quite high, which are indigestible to both ruminant and non-ruminant animals (Querubin et al. 1989). However, it is not recommended as pure feed since it lacks three essential amino acids (lysine, methionine and histidine). It can be mixed with rice bran, corn bran, or other feedstuff as ration. Most rations with 20-25% azolla have given succesful results (Quebral 1989).
| Table 2: Cell wall components of Azolla microphylla | |
|
Constituent |
% DM |
|
Neutral detergent fiber |
67.8 |
|
Hemicellulose |
13.3 |
|
Acid detergent fiber |
44.5 |
|
Cellulose |
9.46 |
|
Lignin |
27.4 |
|
Silica |
7.67 |
| Source: Querubin et al. (1989). | |
A case study in raising local rabbit of household scale in Semarang, feeding ration with the following composition 90% fresh azolla mix with 5% rice bran, and 5% tofu waste. The ration was fed to pregnant rabbit, young rabbit, and suckling kits on the average of 360-400 g/head/day (Rp.125.00/head/day in price) for 2 weeks. The result showed that 0% mortality, no diarrhea occurrence, and better growth for suckling kits. In young rabbit (male or female) also no diarrhea and no hair fall observed, while the performance or libido is stable. On the other hand, in pregnant rabbit after 2 weeks feeding the ration showed an abortion three days before partus without any clinical sign. However, for the partus does, the kits could be live for 2-3 hour only. The ration with azolla as the main feedstuff was palatable, no feed left so that the cages were dry and good for rabbit’s health (Ristiarso 2008 per.com).
According to Saskiardi (1986), azolla could be used to replace green bean in local rabbit’s ration as high as 2.5, 5.0, 7.5, and 10% showed no differences in daily weight gain 11.64, 9.29, 8.71, and 6.85 g/head/day and carcass percentage 49.69, 52.28, 54.07, and 50.69%. Lestari et al (1997) mentioned that utilization of Azolla microphylla as natural lysine source in the form of protein concentrated leaf meal (PCLM) in rabbit ration. The slaughter weight was higher in rabbit fed with PCLM as compare to those fed without PCLM (1330 g vs 1103 g). Body weight and carcass percentage in rabbit fed with PCLM compare to those without PCLM in their ration such as 594 g (48.3%) compared to 491g (44.9%), respectively.
Fresh production and protein content of Azolla microphylla was high, therefore it could be used as non-conventional protein source in rabbit ration. Utilization of Azolla microphylla in rabbit ration was better when mix with high fiber feedstuffs. Ration with azolla as the main feedstuff was palatable and did not affect diarrhea in young rabbit or kits. However, it caused abortion when fed to pregnant rabbit.
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Quebral NC 1989: Introduction to Azolla and Its Uses. In: Azolla: Its Culture, Management and Utilization in the Philippines, Nation Azolla Action Program.
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Querubin LJ, Alcantara PF and Princesa AO 1989: Chemical composition of three azolla species (A. caroliniana, A. microphylla and A. pinnata) and feeding value of azolla meal (A.microphylla) in Broiler ration II. Nation Azolla Action Program. p.181-193
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