University of Tropical Agriculture, Thu Duc, Ho Chi Minh City,
The study was conducted with lactating goats (Bach Thao breed) to examine the feasibility of: (1) improving the utilization of leaves from the Jackfruit tree (Artocarpus heterophyllus); and (2) evaluating the use of sugar cane juice as an energy source to balance the protein in the leaves. Milking was once daily at 7.00 am, the kids being separated from their mothers from 12.00 am until 06.30 am the next day. The control diet consisted of ad libitum jackfruit leaves together with a multi-nutritional block (10% urea). The experimental diet was the same as the control plus a supplement of sugar cane juice of 1.5 kg/day. The first two weeks of the experiment were for adaptation to a standard diet (the control diet plus 500 g/day rice bran).The data obtained in the 3rd week on the standard diet were used as covariate to correct the milk yields during the experimental period in weeks 5-8.
The goats supplemented with sugar cane juice had a higher (P=0.063) average milk production (0.43 kg/day) in comparison with the controls (0.32 kg/day). Intake of fresh Jackfruit leaves was lower with cane juice supplement than on the control diet( P = 0.008). There was no effect of the sugar cane juice on rumen pH, ammonia or protozoal numbers.
It is concluded that a diet of sugar cane juice and leaves from the jackfruit tree can be recommended as a diet for lactating goats .
Goats are found in many part of Vietnam and are an important source of income for many small scale farmers. They provide high quality food in terms of meat and milk and are a source of security during famine and emergency periods. In this way the goat contributes a lot, one way or another, to the welfare of poor farmers. On the other hand, it is also important to find an alternative for the cereal-based concentrates which are becoming too expensive for poor farmers. Making greater use of local resources such as leaves of trees and shrubs is one way of developing alternative feeding systems.
The jack fruit tree (Artocarpus heterophyllus ) is cultivated throughout Vietnam and farmers report that it is readily consumed by goats. The aim of this study was to investigate the nutritional value of the leaves from Jack fruit trees and to find out if there would be a benefit from supplementing them with sugar cane juice. It is expected that the results of this study will provide a basis for the selection of promising local fodder species and the design of appropriate diets for goats and have a beneficial environmental impact by encouraging the planting of trees.
Six dairy goats (Bach Thao breed) were randomly assigned to two treatments. Each treatment consisted of 3 animals which were kept in individual pens. The control treatment was free access to fresh jackfruit leaves and a molasses-urea block (MUB). The experimental treatment was the same as the control but with a supplement of fresh sugar cane juice offered at levels up to 2 kg/day.
During the first two weeks of the study, the kids were always with their mothers and allowed to be suckled full-time. The diet of all the goats was jack fruit leaves, MUB and 500 g /day rice bran (standard diet). In the 3rd week the kids were separated from their mothers from 12.00 am to 06.30 am the following day. Milking was by hand at 07.00 am. The feed intake and milk yield during the 3rd week were used as covariates to adjust the corresponding data during the experimental period from weeks 5 to 8. In week 4 the standard diet was gradually replaced by the experimental diets.
Data on milk yield, feed intake, and brix of sugar cane juice were collected daily. The solids content of milk, the weights of the goats (after milking but before feeding) and the dry matter and N content of the feeds were measured every week. At the end of the experiment, rumen samples were taken by stomach tube to determine pH, ammonia and protozoal numbers in rumen fluid. Ammonia was determined by steam distillation followed by titration. The pH was measured immediately using a portable pH meter (combined electrode). Protozoal numbers were determined by counting under the microscope.
The mean values for milk production are presented in Figure 1. The data are the "adjusted" yields after correction by covariance for yield in the standard period (3rd week). Milk yields were higher for the goats supplemented with sugar cane juice in each week of the experimental period. The overall averages were 0.32 and 0.42 kg/day (P=0.064) for the control and sugar cane juice treatments, respectively.
Mean values for the intake of dietary constituents are shown in Table 1. Intake of fresh jackfruit leaves was higher on the control treatment (3.86 kg/day) than when sugar cane juice was given (3.5 kg/day)(P=0.008). Similarly, the total feed dry matter consumed was also higher for the control treatment (P=0.013) .
The effect of sugar cane juice on rumen fermentation parameters is given in Table 2. The pH and the ammonia concentration were not significantly different between the control and sugar cane juice treatment. Protozoal populations also did not differ. All the measured rumen parameters were in the normal range for ruminants fed mainly on forage (rskov and Ryle 1994).
The improvement in milk production when sugar cane juice was given as a supplement to the leaves of the jackfruit tree indicates that the sugars were used efficiently for microbial protein synthesis. Duarte et al (1982) reported good results (0.8 to 1.0 kg/day live weight gain) in Zebu cattle fattened with sugar cane juice using foliage of the legume tree Leucaena leucocephala as the only protein supplement. Even higher growth rates (up to 1.4 kg/day) were recorded by Sanchez and Preston (1980) for animals of high genetic merit (Holstein X Zebu, F1 crosses) when sugar cane juice was supplemented with urea, rice polishings and African Star grass forage. A suspension of ground roasted soya beans in fresh sugar cane juice sucked from a teat attached to a bottle increased the growth in goat kids by between 42 and 55% (from 34-35 g/day to 50-52 g/day) (Nguyen Thi Duyen et al 1996).
The relatively good results on the control treatment in which jack fruit leaves were supplemented only with a molasses-urea block confirm the findings of Keir et al (1997) and Le Thi Bien et al (1996) that this foliage is of high nutritive value for goats.
Results from this and other studies indicate that:
This work was partially supported by a Letter of Agreement with the Food and Agricultural Organization, Rome though the courtesy of Dr Manuel Sanchez.
Duarte F, Elliott R and Preston T R 1982 Fattening cattle with sugar cane juice: effect of the conservation of the juice with ammonia and the use of Leucaena leucocephala as a source of protein and forage. Tropical Animal Production (7) :169-173
Keir Brenda , Preston T R, Orskov E R, Nguyen Thi Duyen and Dinh Van Binh 1997 The nutritive value of tree leaves for goats. Livestock Research for Rural Development. Volume 9, Number 3 ( in press ) .
Le Thi Bien, Nguyen Thi Mui , Dinh Van Binh and Preston T R 1996 Foliage of Trichanthera gigantea, Jackfruit (Artocarpus heterophyllus), banana ( Musa sp ) and Acacia mangium as protein sources for lactating goats fed a basal diet of rice straw and sugar cane tops. Livestock Research for Rural Development, Volume 8, Number 3: 46-50
Orskov E R and Ryle Margaret 1984 Energy nutrition in ruminants. Elsevier Applied Science: London
Sanchez M and Preston T R 1980 Sugar cane juice as cattle feed: comparisons with molasses in the absence or presence of protein supplement. Tropical Animal Production (5) :117-122
Received 1 May 1997
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