R.K. Datta, A. Sarkar, P. Rama Mohan Rao and N.R.
Singhvi
Central Sericultural Research and Training
Institute,
Central Silk Board, Sriramapura,
Mysore, India
INTRODUCTION
Production of green fodder on cultivated land is not very common in India, because of its low economic return. Furthermore, the lack of sufficient arable land with irrigation facilities also restricts fodder production. Such a situation is more acute in the hilly areas of the country. The huge cattle population in areas depends only on the leaves of certain tree species. Trees have the advantage that they can be planted on hills, on wasteland and at the edges of ponds, and canals, etc. Trees can also be grown on boundaries where regular crops cannot be grown. They have the potential to produce as much green fodder per unit area as agricultural fodder crops. Trees do not need to be watered since they can extract water through their deep and extensive root system. The abilities of trees to extract water from deep underground layers and to withstand drought are outstanding advantages over agricultural fodder crops. Trees also do not need such heavy inputs in the form of fertilizers, pesticides, fungicides and labour, as are needed for growing agricultural crops.
Of all the tree species used as fodder, mulberry (Morus sp.) occupies a significant place as it grows anywhere, either in the form of have tree or shrub. Mulberry is believed to have originated in the foothills of the Himalayas and has been exploited for rearing silkworm in China since at least 3 500 BC. Sericulture then spread to India and to other countries. Although mulberry is the only food for the silkworm, its casual use as animal feed has also been known for a long time.
DISTRIBUTION OF MULBERRY
Mulberry is distributed throughout the world as it has enough plasticity to survive under disruptive environmental conditions. At least 30 countries are now producing raw silk with mulberry and silkworms. In some of these countries, the use of mulberry leaf as fodder has also been adopted. Mulberry can be grown successfully in all conditions, even in tropical, subtropical and temperate climates. It can survive with rainfall ranging from 400-4 500 mm per annum. Although the optimum temperature for growth is between 18 and 30°C, mulberry can survive even when the temperature goes beyond 48°C or below 0°C.
Mulberry can therefore be considered a universal plant, which can grow anywhere under varied climatic conditions. Although this does not guarantee successful silkworm rearing, the plant’s wide adaptability can be exploited in plantations, fully or partly, for animal feed.
MULBERRY AS ANIMAL FEED
The important role of green leaves in supplementing animal feed is unquestionable. In the developing countries, cereal straws and grasses are fed to animals, but they cannot support full performance because of their poor nutritive value. In most places where concentrates are also provided, the diet is not balanced. Mulberry leaf supplementation can improve the efficiency of the whole diet.
In addition, because of increasing pressure from the human population and to higher incomes earned from cereal and cash crops rather than from forage crops, more agricultural land cannot be set aside for fodder production. Another consequent advantage of mulberry is that it can be grown either as a tree or a shrub and harvested several times a year.
In countries such as India, where mulberry is primarily grown for sericulture, excess leaves and leftovers are fed to cattle, sheep and goats. In hilly areas, where mulberry trees are abundant, their leaves are fed to animals. Of the different species available, Morus alba and other species that are suitable for silkworm rearing are cultivated in the plains and on hilly ground.
Morus serrata, Morus laevigata and Morus australis are grown in the hills. Because of their deep root system, the leaves remain green for most of the year, except in winter when the leaves fall.
As a result of the above advantages, mulberry can be considered as a perennial source of feed for most of the year.
Mulberry fodder is considered to be of good quality (Majumdar, Momin and Kehar, 1967a, b). Leaf yield varies with nutrient supply and irrigation. In general, under irrigation with the recommended dose of fertilizer, mulberry yields nearly 35-45 tonnes of fresh leaf/ha/year. On a dry matter basis, leaves contain an average of 20-23 percent CP, 8-10 percent, total sugar, and 12-18 percent minerals. The leaves contain nearly 70 percent moisture. The cell wall constituents are neutral detergent fibre 45.6 percent, cell contents 54.4 percent, acid detergent fibre 35.0 percent, hemicellulose 10-40 percent, lignin 10 percent, cellulose 21.8 percent and silica 2.7 percent (Lohan, 1980). The contents of minerals are as follows: magnesium, 0.52-1.25 percent; chlorine, 0.02-0.29 percent; sulphur, 0.18-0.76 percent; potassium 0.93-3.19 percent and sodium 0.13-0.23 percent (Majumdar et al., 1967a, b). Tannin accounts for 0.85 percent in leaf DM. The chemical composition of the leaves varies from season to season. In hilly areas where the plants are not pruned repeatedly the protein content gradually decreases from February onwards, and minimum values are found in December when leaf fall starts. Like nitrogen, phosphorus also shows the same trend, its maximum content being in February.
Mulberry leaf stalks and leftovers, after silkworm feeding, are generally fed to cattle. Their composition on a DM basis is 11.5 percent CP, 34.0 percent CF, 76.5 percent total carbohydrate, 9.3 percent total ash, 1.6 percent Ca and 0.2 percent P. The calculated values were 70.8 percent for digestible CP, 48.4 percent for total digestible nutrients and 35.6 percent for starch equivalent on a dry basis. The balance of N, Ca and P were positive and animals also gained weight (Subba Rao, Amrith Kumar and Sampath, 1971).
A trial feeding of mulberry leaves to sheep was conducted by Jayal and Kehar (1962). The digestible nutrients of leaves on a DM basis were 10.7 percent for CP, 8.3 percent for CF and 39.6 percent for total digestible nutrients.
Narayana and Setty (1977) indicated that incorporation of 6 percent shade-dried mulberry leaves with poultry feed increased egg production.
MULBERRY AS CATTLE FEED
To ascertain the effect of feeding leftover mulberry leaves with stalks, a study was conducted by the authors during 1999-2000 at Kolar, the traditional sericultural area of Karnataka (India) with hybrid milk cows (local x Jersey) at the farmer level. Twenty farmers, who regularly feed mulberry leftover leaves and stalks after silkworm feeding, were selected. In general, only one feeding of mulberry leaves at noon was carried out. There was a control group of ten cows. On average, 15-20 kg of either full mulberry leaves (if there were any in excess after rearing) or leftover leaves with stalks were fed to the cows.
In the case of the control group, the same feeding schedule was followed except at noon, when mulberry leaves were replaced by cereal straw. The amount of feed supplied at different times is shown in Table 1.
TABLE 1
Schedule of feeding and quantity of feed given to milk cows.
|
Feeding time |
Control feed |
Mulberry feed |
||
|
|
|
kg |
|
kg |
|
06:00h |
Fodder grass |
15 |
Fodder grass |
15 |
|
11:00h |
Finger millet grass |
20 |
Finger millet grass |
20 |
|
13:00h |
Rice straw |
15 |
Mulberry |
15 |
|
22:00h |
Concentrate |
10 |
Concentrate |
10 |
The study clearly shows that mulberry improved feed quality significantly. Nearly 34 percent higher milk yield was recorded when mulberry was provided once a day. Milk yield was found to increase both morning and evening, although the improvement was found to be more pronounced evening milking. Fat content was higher in cows fed mulberry (3.50 against 2.94 percent). Interestingly, cows fed mulberry conceived 24 days. However, 25 percent of farmers believe that continuous feeding with mulberry can cause termination of pregnancy in some cases for unknown reasons. Experiments are required to study this theory.
TABLE 2
Comparison of normal feeds vis-à-vis partial mulberry feeds with respect to economic characters in hybrid cows (local x Jersey)
|
Group |
Milk yield (litres) |
Fat |
Days to conception |
||
|
Morning |
Evening |
Total |
|||
|
Control (n = 10) |
8.4 |
6.7 |
15.1 |
2.94 |
100 |
|
Mulberry (n = 20) |
11.0 |
9.2 |
20.2 |
3.50 |
77 |
|
"t" value |
9.203 |
9.366 |
9.747 |
21.43 |
19.56 |
|
Significance |
P < 0.01 |
P < 0.01 |
P < 0.01 |
P < 0.01 |
P < 0.01 |
Production of green fodder on cultivated land is constrained by difficulties in setting aside sufficient cultivable area for fodder production, lack of irrigation facilities and other inputs; and low economic returns compared to cash crops. Mulberry trees that can be grown under varied climatic condition, including fallow and wastelands not fit for agriculture can be used, totally or partly, for producing nutritious green fodder. The study conducted by this Institute directly with farmers proved that feeding mulberry as part of the daily ration of cows, improved the quality and quantity of milk and reduced calving intervals.
BIBLIOGRAPHY
Jayal, M.M. & Kehar, N.D. 1962. A study on the nutritive value of mulberry (Morus indica) tree leaves. Indian J. Dairy Sci., 15(1): 21-27.
Lohan, O.P. 1980. Cell wall constituents and in vitro DM digestibility of some fodder trees in Himachal Pradesh. Forage Res., 6: 21-27.
Majumdar, B.N., Momin, S.A. & Kehar, N.D. 1967a. Studies on tree leaves as cattle fodder. 1. Chemical composition as affected by the stage of growth. Indian J. Vet. Sci., 37(b): 217-223.
Majumdar, B.N., Momin, S.A. & Kehar, N.D. 1967b. Studies on tree leaves as cattle fodder. 2. Chemical composition as affected by the locality. Indian J. Vet. Sci., 37(4): 217-223.
Narayana, H. & Setty, S.V.S. 1977. Studies on the incorporation of mulberry leaves (Morus indica) in layers’ mash. Indian Vet. J., 56(9): 778-787.
Subba Rao, A., Amrith Kumar, M.N. & Sampath, S.R. 1971. Studies on mulberry (Morus alba) leaf stalk palatability, chemical composition and nutritive value. Indian J. Vet. Sci., 48: 853-857.
