7. Productivity and Chemical Composition of Several Mulberry Species (Morus Spp) Agains Spacing Plant, and Cutting Age

The cultivation of mulberry as forages is scarce in Indonesian feeding system for ruminant production, although many studies have indicated its nutritional potential as animal feed especially ruminants. This study was aimed to investigate the effects spacing of plant and cutting age on productivity and chemical composition of some species mulberry plants. The experiment was conducted in a randomized block design with factorial treatments. The factors species were (M. indica cv kanva, M. nigra, M. cathyana, and M. Multicaulis), the spacing of plants (1 x 0.5 m, 1 x 1 m and 1 x 1.5 m) and cutting ages (210, 240, and 270 days after planting). The results showed that species, M. multicaulis and M. cathyana are the highest growth, using a spacing of 1 x 0.5 m with cutting age 270 days after planting. Dry matter production highest (P < 0,05) in M. Cathyana at spacing of 1 x 0.5 with cutting age 270 days after planting. The ratio of leaves and stems of plants are affected by age, the highest proportions of leaf is obtained at the cutting age of 210 days. Chemical composition were highest in M.multicaulis at the age of 270 days. The highest content of organic matter (OM) were found in M.Kanva and not different with M. Nigra at the age of 270 day after planting. In treatment of cutting ages have no effect (P < 0.05) on the Crude protein (CP), ADF, NDF, lignin and tannin content. The average content of CP obtained gained 20.69%, 32.38% ADF, NDF 33.99%, 12.45% lignin and tannin 0.3%. Concluded that mulberry plants with a plant spacing of plant 1 x 0.5 and 270 days after plant have more advantages for use as animal feed.


Background
Mulberry (Morus spp) Is one type of forage that can be used as animal feed protein source (Ondiek et al., 2000;Miller et al., 2005). Mulberry plants belonging to the genus Morus, family Moraceae and Ordo Dicotyledonae. It is estimated that there are 68 species of the genus Morus spread across Asia (Datta, 2001), and in China there are more than 1000 varieties (Sanchez, 2000). Some species such as Morus indica (white mulberry), Morus nigra (black mulberry), Morus cathyana, Morus multicaulis, Morus rubra (red mulberry) has spread and adapt well in the tropics and sub tropics ranging from altitude 0-4000 m asl. Mulberry cultivation has grown as a source of feed silkworms for silk textile interests. The crude protein (CP) content of mulberry can reach 24.9% (Saddul et al., 2004) with a digestibility level of between 75-85% (Nguyen Xuan Ba et al., 2003;Nguyen Xuan Ba et al., 2004). The crude protein content is comparable to some plant species of legume trees that ranged from 20-28% (Khaito et al., 1997). Mulberry can be used as a substitute supplement concentrate up to 75% without affecting to the production and quality of milk (Yulistiani, 2008).
Mulberry can be used as a protein supplement throughout the year (Sanchez, 2001), then this plant is one of alternative feed sources of potential to be developed optimally. Some important factors that improve development and production of mulberry plants is a spacing of plant and cutting age (Almaida and Fonseca, 2002). It is known that the productivity and nutritional quality of forage is influenced by age (growing phase) as well as the composition of the fractions plants, such as the ratio of leaves / stems. In addition, the frequency of cuts can affect the production of dry matter, morphological composition, nutritional composition and digestibility of the feed (Kabi and Bareeba, 2008). There fore, defoliation management information concerning spacing of plant and cutting age are important in managing the plant and the production of feed to produce optimal nutritional quality, when used as forage. This study aims to determine the agronomic characteristics (plant height growth, productivity, the ratio of leaf / stem), as well as some of the nutritional composition mulberry agains of spacing plant and cutting age.

Materials and Methods
The research was done in the experiment forage and loboratory of animal feed and nutrition Indonesia goat research station, Sungei putih North Sumatera. The located at an altitude of ± 50 m from sea level, with the soil type podsolid (red sand) with an average rainfall of 1800 mm/year. The material used in this study are four species of mulberry seeds originating from the collection of forages in Indonesia goat research station.
Preparation of cultivation was done with land clearing, spraying herbicides, hoe with tractors. Nursery plants derived from stem mulberry tree that is quite old with a cutting height of 0.5 meters from the ground. Pieces cuttings each branch length of 15-20 cm or have 3 buds with a diameter of 1-3 cm. The selection of the seeds are good and healthy cuttings (stem shiny, not damaged (deformed), does not rot and protected from disease borer). Cuttings planted in polybag and placed in the area who have given shade paranet with light intensity of approximately 50%. The plants treated with weeding and watering every day until 2 months old. Then plants were transferred to a plot in accordance with the treatment that has been set with a spacing of 1x0,5m, 1x1m, 1x1,5m. Treatment is done until the time of harvest for the provision of basic fertilizer (manure) 4 tons / ha, chalk as much as 10 tonnes / ha and chemical fertilizers such as urea (300 kg / ha), TSP (400 kg / ha) and KCL (200 kg / ha).
Mulberry harvested at 210, 240, and 270 after planting with cutting height of 100 cm above the ground. Yields were weighed and then the separation between the leaves and stems fractions to determine the biomass production and the ratio of leaves / stems. To obtain a dry matter (DM), samples were taken of 500 g then dried at a temperature of 65 0 C for 72 hours in the oven, then using a grinder (hummer mill) with a filter diameter of 1.0 mm. Samples were analyzed in the laboratory to determine the content of crude protein (CP) with the detruksi method test auto-analysis of AOAC (2005), ADF (acid detergent fiber), NDF (neutral detergent fiber), lignin (gravimetric methods) and tannins (spectrophotometry method). A proportion of samples entered in the electric furnace at a temperature of 600 0 C for 8 hours, and then weighed to determine the organic material (OM) with the gravimetric method.
The study was conducted in a randomized block design faktorial pattern, consisting of 3 factors. The first factor are species of mulberry (Morus indica cv Canva, Morus nigra, Morus cathyana, and Morus multicaulis). The second factor are spacing of plant (1 x 0.5 m, 1 x 1 m and 1 x 1.5 m) and the third factor cutting ages (210, 240, and 270 after plant). Consists of 3 replication. Data was analyzed using ANOVA method, and if there is a significant difference (P < 0.05) followed by Duncan's multiple range test, (DMRT).

Results and Discussion High Growth of Plant
From the result of observation, the longer cutting age it is plants grow higher. Winata et al. (2012) indicates that the higher plant have greater production obtained. Data obtained from the results of this study indicate that the species M. multicaulis is the tallest plants, not different with M. Cathyana. The growth is strongly influenced by the spacing of the 1 x 0.5 and 1 x 1cm and the cutting age of 210, 240 and 270 days. Spacing 1 x 0.5m at M. Multicaulis generating plant height 166.67cm, 341,67cm, and 416,67cm, and at a spacing of 1 x 1m produce 243,33cm, 281,67cm, and 353,33cm. While the species M. cathyana had an average growth of 155.00, 273.33, and 306.67 at a spacing of 1 x 0.5 m. 193.33, 196.67 and 400.00 on the spacing of 1 x 1m. These results were significantly differences (P < 0.05) compared with the species M. Kanva and M. Nigra (Table 1), and comparable to those reported by (Mohamed et al., 2013;Sutani et al., 1989) that the highest growth mulberry plants are at a distance of 1 x 1 m plants can reach 300 cm. Based on the above results to obtain the highest growth of mulberry plants can use 1 x 0.5 m spacing of the cutting age of 270 days after planting. Different superscripts in a column or same row indicate significant differences (P < 0.05).

Dry matter production
The result of the average production in dry matter (DM) mulberry plants are presented in Table 2. Production of DM significant (P < 0.05) against spacing of 1 x 0.5 m, was obtained in the species M. Kanva with cutting age of 210 days can be reached 1.96 tons/ha. DM production was also affected by the age of cuts, there is the species M. Kanva   Different superscripts in a column or same row indicate significant differences (P < 0.05).
Production increased at a spacing of 1 x 0.5 m, it is likely caused by the number of plants / ha more than the distance of the plant 1 x 1 m and 1 x 1.5 m. These results differ from the results reported by Eltayb and Warag (2003) showed that the highest production growth and are at a spacing of 1 x 1 m compared with 1 x 0.5 m, 1 x 1.5 m, and 2 x 2 m in some species (M. alba, M. ma1lotfolia, M. Acidosa, and M. mesozygia tiliaefolia). The same recommendation with a spacing of 1 x 1 m were reported by Sutani et al. (1989). This may occur because of differences in the mulberry species and soil conditions (alluvial soil) used in the study.
The longer age generally will increase production of biomass Elevitch and Francis (2006) and Fuskhah et al., 2009). This is related to the use of nutrition obtained in the branch shoots during the growing period and utilized to the fullest. According Rahman (2002); Winata et al. (2012), the longer defoliation allow the plant to increase production as well as the chance a longer time to develop roots as well as the accumulated result of photosynthesis into roots system. Thereby, based on the test results above, to obtain optimum DM production can use a spacing of 1 x 0.5 with cutting age 270 days after planting.

The ratio of leaf / stem
Very important to know that proportion of leaf / stem (Shehu et al., 2001), because the forage plants that have much leaves is a good feed quality, then Gustavsson and Martinsson (2004) stated that the parts of the plant are the most palatable and have a higher quality is a fraction of the leaves, affect the amount of consumption and nutrient content. In general, the level of consumption and the amount of nutrients are obtained on the leaves was higher than in the stem (Smart, 1998).
The ratio of leaf / stem mulberry plants in this study (Table 3), shows that the planting distance was not significant (P > 0.05) on the ratio of leaves and stems, but significantly affected by the cutting age. Leaf ratio is highest at the age of 210 days significantly differences (P < 0.05) to the cutting age of 240 days found in the species M. kanva with spacing 1x0,5 and 1x1,5. M. nigra with spacing 1x0,5, 1x1 and 1x1,5 and M. Multicaulis with a spacing of 1x0,5 m. This indicates that the higher age cuts will lower the proportion of leaves obtained. Different superscripts in a column or same row indicate significant differences (P < 0.05).
Decrease of ratio leaf in accordance with those reported by (Herdiawan and Suteddi, 2012;Tarin et al., 2010;Bonesmo and Belanger, 2002) states that the increase in age of the plant followed by an increase in the proportion of branches as well as the content of the cell walls (fibers) . So that when seen from the aspect of its agronomic, the first cut at the age of 210 days is an optimal defoliation management in the utilization of mulberry as forage plants because the leaves possess a fraction higher.  Savitri et al. (2013), the long age causing the plant to have more opportunities make the process of photosynthesis, enabling the plant increases production of the canopy so that can increase organic matter content in plants.

Chemical composition
Cutting age do not affect to increase the content of CP, ADF, NDF, lignin and tannin. The content of CP obtained ranged between 19% -21.73%. This figure is relatively lower than the results Saddul et al. (2003), 24.9%.  reported the CP content of mulberry plants ranged from 22.2 -24.3%. Bamicole et al. (2005) 23.2%, while Sanchez (2000) reported between 15-28%. In this study the cutting age at the 210 days with an average content of CP (20.69%) has been quite effective cutting as animal feed. The average content of ADF obtained (32.38%), higher than Flemingia (30%) and lower than Acacia (45%) reported by Thanh et al. (2004). The average content of NDF obtained (33.99%), higher reported by Jefferson (2005), which contains 30.5% NDF. The average lignin content of each forage mulberry in this study 12.45%, is low compared with reported by Yogesh (2013) amounted to 21.42%. Tannin content obtained by an average of 0.3%, relatively moderate and comparable to the tannin content in some species of mulberry plants (0.13 to 0.36%) were reported Srivastava et al. (2006), (16 -35%) (Chaitali et al. 2014). But relatively higher (0.58%) than those reported by Datta (2002).

Conclusion
Concluded that the species M. Multicaulis has more advantages than the other three species, the use of a spacing of 1 x 0.5 and cutting age of 270 days after planting showed higher growth of mulberry plants, as well as a lot of advantages to the DM production, the ratio of leaves and stems, and chemical composition especialy to DM and OM content.