R. T. Fomunyam and F. Meffeja
Institute of Animal Research
Mankon, Bamenda, Cameroon
Summary
Introduction
Materials and methods
Results and discussion
Acknowledgements
References
Maize stover/oilseed cake diets fed to sheep and goats showed that maize stover/cottonseed cake diet was consumed more than (P<0.01) maize stover/groundnut cake diets. Sheep (P<0.01) consumed significantly more feed than goats. Mortalities were higher in goats than sheep. In vivo percent digestibility coefficients showed that maize stover/brewers wet grain silage was comparable to alkali-treated low quality roughages.
The northwest and western provinces of Cameroon produce about 800 t of maize and about 600 t of rice annually. Thus about 3080 t of farm residues (maize stover, maize cobs, rice straw, rice bran, etc) are available (Fomunyam 1984). In these regions two million sheep and goats are tethered during the cropping season (mid-March to mid-October) and, during the months after harvests, are extensively grazed in crop fields while the daily diet is supplemented with household refuse such as cocoyam, plantain, banana and cassava peels, maize or rice bran, brewers grains, oilseed cakes, etc.
This management system is self-limiting in that herd sizes are small. Reproduction is not controlled and is frequently affected by poor nutrition. Females are randomly bred and young are born small and weak. Mortalities are high for adults and young alike. Bush fires in the dry season reduce available feed to almost nothing and weight losses increase.
Moreover, there is an increased trend towards two-season cropping (i.e., producing food in both the rainy and dry seasons) in order to increase production to meet the demand of a population growing at an annual rate of 2.4%. Also, more and more of the grazing land will inevitably be needed to ensure extensive cultivation of food crops. In the final analysis, then, sheep and goats must be confined.
The consequence of these constraints is that sheep and goat farmers are tending to reduce their already small herd sizes from a range of 5-10 to about 1-2, or are completely replacing small ruminant production with non-ruminant production.
In order to establish feeding packages for sheep and goats in the dry season, a series of studies have been initiated in an attempt to quantify village sheep and goat feeding patterns.
In the first of two trials, 12 grassland dwarf sheep and goats, 6 months old, with an initial average weight of 14-16 kg, were fed field-dried maize stover supplemented with either cottonseed cake or groundnut cake in a 2 x 2 factorial. The maize stover was hand-chopped in 3 cm pieces and fed free choice in an 80:20 maize stover/oilseed cake ratio for 12 weeks (Table 1). Salt and water were provided ad libitum.
Table 1. Composition of maize stover/oilseed cake diets fed sheep and goats (%).
|
Components |
Diet I |
Diet II |
Maize stover at harvest |
Maize stover field-dried |
|
Maize stover groundnut cake |
Maize stover cottonseed cake |
|||
|
Moisture |
7.5 |
6.6 |
20.9 |
5.9 |
|
Crude protein |
15.2 |
13.7 |
6.8 |
5.6 |
|
Crude fibre |
30.3 |
47.4 |
30.2 |
36.2 |
|
Ether extract |
3.3 |
2.2 |
2.7 |
1.7 |
|
Organic matter |
83.2 |
92.8 |
92.2 |
96.8 |
In a second trial, 3 cm maize stover pieces and brewers wet grains (60% DM) mixture were ensiled in a pit 90 cm x 150 cm x 90 cm. The pit was lined with plastic sheets. Each layer was packed by four men trampling on the material and the final layer was covered with plastic sheets, banana/plantain leaves and earth 30 cm high. The chemical composition of the mixture was: dry matter, 59.1%; crude protein, 7.8%; crude fibre, 26.2%; ether extract, 3.2%.
Digestibilty trials, using six adult grassland dwarf rams full-fed, were carried out. An 8-day collection period followed a 10-day feeding period. Faeces and feedstuffs were separately dried in a forced draught oven and pooled for analysis.
Table 2 shows that the maize stover/oilseed cake diets were poorly consumed by sheep and goats and at maintenance levels only, although the ruminants consumed significantly (P<0.01) more of Diet I than Diet II. Sheep ate significantly (P<0.01) more of the diets than goats. Weight gains and percent mortalities of animals followed the same pattern as for feed intake.
The low intakes and subsequent weight gains show that the diets were not very palatable, as has already been shown by several authors feeding low quality forages (Orskov, 1977; Theander, 1981).
The increased intake of cottonseed cake-based diet rather than groundnut cake-based diet, might be because cottonseed cake is less oily (3.9% ether extract) than groundnut cake (11.6% ether extract) and thus more palatable. The general low intakes of both diets may be due to the bulkiness and dryness of the maize stover, although the ruminants have been observed nibbling at the stover in maize fields and in this experiment.
Table 2. Feed intake, weight gain and percent mortalities of sheep and goats fed maize stover/oilseed cake diets.
|
Diet |
Species |
Daily feed intake (g DM/animal) |
Daily weight gain (g/animal) |
Percent Mortality |
|
|
I |
Sheep |
201.0y |
0.4y |
16.7y |
|
|
Goat |
129.5x |
0.04x |
67.3z |
||
|
II |
Sheep |
225.5y |
2.5z |
0.0x |
|
|
Goat |
147.6x |
0.6y |
16.7y |
||
|
S.E.M. |
15.24* |
0.25* |
5.7* |
||
|
Dietary means |
|
|
|
|
|
|
|
I |
|
164.7x |
0.2x |
42.0x |
|
|
II |
|
201.6y |
1.6y |
8.4y |
|
|
S.E.M. |
|
7.12* |
0.6* |
3.2* |
|
Animal species means |
|||||
|
Sheep |
228.3y |
1.5y |
8.4x |
||
|
Goat |
137.5x |
0.3x |
42.0y |
||
|
S.E.M. |
7.12* |
0.6* |
3.2* |
||
x, y, z: Means within columns followed by the same letters are not significantly different at P<0.01.* Significant.
Devendra and Burns (1970) observed that the feeding habits of goats were unlike those of other ruminants; goats often prefer browse plants and low quality herbage. It could be expected from this that goats would consume more of the present diets than sheep but the reverse was observed. Bell and Lawn (1957), Chaudhary and Majinndar (1962) and Devendra (1967) have shown that digestion in goats is similar to the digestion of sheep and other ruminants. It is not clear why the daily feed intake by goats has been so poor but the mortalities must have been due to this low intake.
Table 3 shows that the digestibility of maize stover/brewers wet grains silage was similar to results obtained by other workers from alkali-treated maize stover. Mehrez et al (1981) showed that dry matter digestibilities of 61.0% and 60.3% for alkali sprayed or soaked maize stalks were comparable to results observed in this study. However, crude fibre values of 74.7% and 75.1% from their study were higher than values of 62.3% observed in this study, but crude protein values were 45.5% and 26.5% in their study - much lower than values of 63.8% in the present study. The observation of Guggolz et al (1971) showed that dry matter digestibility of 60% for 5% ammonia-treated maize stover was similar to the present results.
Table 3. In vivo digestibility coefficients (%) of maize stover/brewers wet grain silage.
|
Digestibility coefficients |
Percent |
|
Dry matter |
57.2 |
|
Crude protein |
63.8 |
|
Crude fibre |
62.3 |
|
Ether extract |
77.5 |
In the above studies, the diets were supplemented with protein sources as well as mineral supplements, whereas in this study, salt was the only added nutrient. In related studies, digestibility values of sodium hydroxide-treated Hyparrhenia (Katagile, 1981) and ensiled treated alkali straw (Garmo, 1981) were similar to values obtained from these studies.
It should be noted that although the above diets are not fed for a considerable time by farmers, several combinations of diets are fed interchangeably and probably the nutrient requirements, at least for maintenance, are met by these diets.
Considering that Cameroon does not produce chemicals, it is suggested that the improvement of these diets, as outlined above, would be economically feasible because there would be a reduced loss of foreign exchange from importing chemicals and reduced pollution of the land via chemicals in wash water from treated roughages. -The technology of these improved feeding patterns can be easily adopted by farmers, in contrast to transferred technologies of sophisticated roughage treatment methods.
Part of the study was carried out with the assistance of Mr Evini Bengono; his assistance is gratefully acknowledged. The authors also wish to thank the Ministry of Higher Education and Scientific Research (MESRES) for the funds that supported the study.
Bell F R and Lawn A A, 1957. The pattern of rumination behaviours in housed goats. British Journal of Animal Behaviour 5:85-89.
Chaudhary H P S and Majinnder B N. 1962. Comparative usefulness of the indicator technique in digestibility determinations of different species of animals. Annual Biochemical Experimental Medicine 22:297-302.
Devendra C, 1967. Studies in the nutrition of the indigenous goat of Malaya V: food conversion efficiency, economic efficiency and feeding standards. Malaysia Agricultural Journal 46: 204-216.
Devendra C and Burns M, 1970. Goat production in the tropics Commonwealth Agricultural Bureau, Farnham Royal, Bucks, U.K.
Fomunyam R T. 1984. Report on the workshop on: Consultative guidelines for research on crop residues and agro-industrial by-products. ILCA, Addis Ababa.
Garmo T H. 1981. Ensiling of alkali-treated straw. Report on the workshop on Utilization of low quality roughages in Africa. Arusha, Tanzania.
Guggolz F H. McDonald G M, Walker H G. Garret W N and Kohler G O 1971, Animal Science 33:284.
Kategile J A, 1981. Simultaneous cutting and alkali treatment in a modified forage harvester for ensilling. Report on the workshop on: Utilization of low quality roughages in Africa. Arusha, Tanzania.
Mehrez A Z. El Shinnawy A, Abou-Raya A K and El Ayek M, 1981. A proposed approach for evaluating sodium-treated roughages. Report on the workshop on: Utilization of low quality roughages in Africa. Arusha, Tanzania.
Orskov E R. 1977. Livestock Production Science 4:165.
Theander O. 1981. Chemical composition of low quality roughages as related to alkali treatment. Report on the workshop on: Utilization of low quality roughages in Africa. Arusha, Tanzania.
