D Wegad and R D NDumbe
Mesres - I.R.Z., Bambui, Cameroon
Abstract
Introduction
Materials and methods
Results and discussion
References
Twelve (12) young Zebu bulls of Gudali breed, 276 kg average liveweight and 2 ½ years of age were randomly put into 4 groups of 3 animals under intensive feeding system to determine the effect of different protein supplements on growth, and intake of chopped, dried maize stover. A control group was fed stover and libitum only, and the other groups were fed daily 750 g cottonseed cake/head, 1 kg leucaena hay or 900 g of leucaena/cottonseed cake (66:34; w/w).
Significant differences were observed on average daily liveweight gains. Animals on leucaena and its mixture registered higher daily gains (236 g) and (325 g) respectively, followed by cottonseed cake (154 g); The control group lost weight (-8.0 g/d).
Contrary to the liveweight gains, animals fed on leucaena and its mixture had lower maize stover intakes, 3.35 kg DM/animal/day and 3.70 kg DM respectively, while those on cottonseed cake and the control group ingested respectively 4.72 kg DM and 4.16 kg DM maize stover.
It is concluded that during the critical period in the southern part of Cameroon, small-scale farmers can prevent loss in liveweight by utilizing simple available rations.
In southern Cameroon small-scale farmers practice mixed farming. Animals, especially ruminants, lose 20 to 30 percent of their liveweight during the dry season due to low productivity of pasture (Hoste 1974). Therefore six years of studies on the utilization of rice bran and rice straw in ruminant feeding have been implemented at the animal research centre in Bambui. Satisfactory results with the incorporation of 100 percent rice bran (NDumbe 1979, 1980) and 60 to 80 percent chopped maize stover (NDumbe et al.; 1982, 1984) were obtained. But the use of concentrate supplements, or the chemical, physical and microbial treatments generally recommended (Nicholson 1981; Hartley 1981) to improve the low energy and protein in lignified straw (tong et al. 1983) are not actually applicable to small scale farmers. There is a great need to prevent weight loss by using simple techniques and readily available rations.
A study was therefore undertaken to evaluate the effect of different protein supplements on the growth and feed intake of young bulls fed intensively on chopped dried maize stover.
Animals
Twelve Gudali Zebu bulls, of average liveweight 276 kg and aged 2 ½ years were randomly assigned to 4 groups of 3 animals each. The animals were housed in a roofed, half walled shed with a concrete floor, treated for worms and ectoparasites, and injected with A, D, K, E polyvitamins.
Feed and Feeding
A two week adaption period of maize stover was followed by a 12 week experimental period during which maize stover was given ad libitum at the rate of 120% of the intake. The diets were composed of:
|
basal diet |
- ad libitum dried chopped maize stover. |
|
diet 1 |
- basal diet + 750 gm cottonseed cake/animal/day. |
|
diet 2 |
- basal diet + 1000 gm leucaena hay/animal/day |
|
diet 3 |
- basal diet + 900 gm/day of a mixture of leucaena hay and cottonseed cake in the ratio of 66:34 (w/w). |
The supplement was given separately each morning before the basal diet of maize stover. Water and a mineral supplement (50:50 common salt/bone meal) were given separately ad libitum. Chopped maize stover and refusals were weighed each morning. Animals were weighed fortnightly from the beginning of the adaptation period to the end of the experimental period.
The chemical composition of maize stover and leucaena was determined using the methods of Van Soest (1967) for cell wall materials and nitrogen was measured by a Kjeldahl procedure; these figures are shown in Table 1.
Table 1: Chemical composition of ration ingredients (%).
|
|
Dry Matter |
Crude Protein |
Cellulose |
Hemicellulose |
NDF |
ADF |
Lignin |
Ash |
|
Maize Stover |
92.05 |
4.05 |
29.20 |
19.50 |
42.60 |
62.10 |
12.50 |
9.50 |
|
Leucaena hay |
89.05 |
25.53 |
8.60 |
12.76 |
22.22 |
34.99 |
12.76 |
14.56 |
|
Cottonseed cake |
88.60 |
34.05 |
- |
- |
- |
- |
- |
- |
|
Crude protein in daily supplements fed |
basal diet |
diet 1 |
diet 2 |
diet 3 | ||||
|
|
0 |
255.37 |
255.30 |
255.84 | ||||
Liveweight gains and feed intake were submitted to analysis of variance and Fisher's test was applied to determine significant differences among treatments.
Intakes of maize stover and liveweights are given in table 2. Cottonseed cake slightly but non-significantly increased maize stover intake, but both leucaena and leucaena/cottonseed mixture reduced maize stover intake significantly (P<0.5).
Table 2. Effects of diets 1, 2 and 3 on dry matter intake of maize stover and on liveweight gains in cattle over an experimental period of 12 weeks.
|
Rations Parameter |
Basal Diet |
Diet 1 |
Diet 2 |
Diet 3 | |
|
No. of animals |
3 |
3 |
3 |
3 | |
|
Liveweight (kg) |
|
|
|
| |
|
|
- initial |
275 |
277 |
276 |
277 |
|
|
- final |
274 |
290 |
295 |
305 |
|
LWG (g)/day |
-8a |
154b |
236c |
325d | |
|
Daily maize stover intake kg DM/animal |
4.16a |
4.72a |
3.25a |
3.70b | |
a, b Means in the same row not having common letters differ significantly (P<0.05).
Table 2 shows that the liveweight gains (LWG) of the supplemented groups differed significantly from each other, and all significantly exceeded that from the basal diet of maize stover, which produced weight loss (-8 g/animal/day). In terms of LWG, leucaena hay alone was more effective for animals than cottonseed cake alone. Animals supplemented with the mixture of leucaena hay and cottonseed cake registered the highest LWG, showing the mixed supplement to have been more beneficial for cattle growth than either supplement alone. In the three supplemented groups, the quantity of supplementary protein was the same, and thus LWG was significantly affected by the source of supplementary protein.
Morgan (1977) observed in sheep that finely ground cottonseed meal provided animals with by-pass protein resulting in increased total feed intake (tong and Preston, 1983). The low voluntary intake of maize stover could be the result both of low crude protein content and low digestibility (Finn 1976), in turn probably related to its high lignin content (12%) which limits the fermentable energy available (Lindberg et al., 1984).
While both leucaena hay alone and its mixture with cotton seed cake significantly decreased maize stover intake, the effect of leucaena alone was relatively more pronounced. This might have been due either to its lignin content (12% as in corn stover) or to the toxic effect of mimosine (Jones et al., 1983) which was not assessed, but in view of the gains observed, probably unimportant.
It is concluded that small-scale farmers could avoid animal weight loss during the critical period of the year by using small quantities of higher quality supplements, and consequently reduce animal mortality and weakness due to malnutrition.
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