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| Livestock Research for Rural Development 21 (10) 2009 | Guide for preparation of papers | LRRD News | Citation of this paper |
A fifty-six day trial was conducted to investigate the potentials of Chromolaena odorata (C.O.) leaf meal as a possible egg yolk colourant and its effects on some other egg quality characteristics. Chromolaena odorata leaf meal was included in the formulated diets at 0%, 2.5%, 5% and 7.5% levels.
The trial revealed highly significant (P<0.01) differences among the treatment means for the yolk colour score. At the lowest level of Chromolaena odorata inclusion (2,5%), the minimum standard for yolk pigmentation for individual consumers and for the pastry and confectionery industries was achieved. Also, the dietary inclusion of Chromolaena odorata leaf meal up to 7,5% level did not compromise egg weight, shell thickness, shell weight, albumen height and Haugh’s unit.
It could be concluded that high prospects abound for the utilization of Cromolaena odorata as a possible egg yolk colourant for laying hens and this could mark a turning point from the campaign for its eradication to its subtle cultivation.
Key words: Egg qualities, egg yolk colourant, Siam weed, table egg production
Siam weed (Chromolaena odorata) is a perennial shrub that belongs to the Aster family. It is a highly successful plant that has colonized diverse ecological areas of tropical lands. Its ability to survive long spells of drought as occasioned in many tropical areas and its propensity to resume active growth at the commencement of the rains is unparalleled. Its soil-enriching prowess and its tendency to infiltrate new areas have recommended it as a plant of choice in fighting desert encroachment especially in the Sudano-sahelian ecological zones of Africa.
The medicinal use of Cromolaena odorata has also not gone unnoticed. The astringent properties of the leaf extracts of Cromolaena odorata on the blood vessel (Iwu 1993) has made it a popular plant in the prevention of blood loss from wounds, also its anti-microbial properties has made it a popular choice in disinfecting and treating open wounds (Odugbemi 2006). The anthelmintic properties of the aqueous extracts of Cromolaena odorata have also been widely known among the peasant population of Asia and Africa. Its popularity as an effective therapy against diarrhoea, malaria fever, tooth ache, diabetes, skin diseases, dysentery and colitis has been severally documented (Odugbemi 2006; Akinmoladun and Akinloye 2007).
The use of Cromolaena odorata leaf meal in livestock production has been largely constrained by its unpalatable nature when fed fresh to farm animals. In fact, grazing animals have developed a phobia for it in pasture. The avoidance of Cromolaena odorata by grazing animals might not be unconnected with the offensive odour that emanates from the leaves whenever they are bruised by the grazing animals in their attempt to consume them (Aro 1990). Also the high nitrate content of the leaves has been implicated in the resultant death that ensued from their consumption by animals in the raw form (Sajise et al 1974). This death was probably caused by the conversion of the nitrate either in the feedstuff or in the alimentary canal of the animals to nitrite. The nitrite then combines with the haemoglobin of the blood thus converting it to methaemoglobin, which is unable to act as oxygen carrier and this might possibly lead to the death of the animals through tissue anoxia (Sajise et al 1974). The death of cattle in certain parts of Philippines after ingestion of Cromolaena odorata leaves might have been caused by tissue anoxia.
These shortcomings in the use of Cromolaena odorata as a feed resource for livestock notwithstanding, painstaking research efforts have found ways of tapping the vast potentials of the plant. One of these ways is by sun-drying and converting the fresh leaves to leaf meal. Sun-drying reduces the offensive odour to the barest minimum and improves palatability (Aro 1990; Fasuyi et al 2005).
One of the organoleptic appraisals of the table eggs is the yolk colour score. This internal egg quality is predicated on the appearance of the yolk upon the breaking of the egg for human consumption. High preference and premium are usually placed on eggs with deep yellow to orange yolk colour (Ogundipe et al 1992). Yellow coloured yolk, aside from other aesthetic qualities is considered to be more nutritious with respect to vitamin A and other carotenoid precursors when compared to egg yolk with faded yellow colour. This is the main reason why eggs from local chickens in Nigeria are more treasured because of this organoleptic quality. To command such high premium in the sale of commercial table eggs, some farmers have resorted to the use of highly expensive and imported egg yolk colourants that only ended up in increasing their cost of production and making their product (the eggs) less competitive in the market because of high price (Abeke et al 2008)
To beat down the cost of the expensive colourants, some egg producers have resorted to using leafy vegetables like Celosia, Amaranthus and Corchorus either in the fresh form or as leaf meals to achieve their aim of improving the egg yolk colour score in their layers. This measure has only complicated issues as it has given birth to yet another problem – competition between man and his livestock for these seasonally available leafy vegetables with the concomitant hike in the price of these vegetable products. As a palliative to this problem, the use of the leaf meal of Cromolaena odorata – a supposedly obnoxious weed was investigated in this trial as a possible replacement for the very expensive imported egg yolk colourant in commercial layers’ diets.
The Cromolaena odorata leaves used for this experiment were collected fresh and sundried for four days after which they were milled and stored in jute bags prior to incorporation into the layers diets. Table 1 gives the proximate composition of Cromolaena odorata leaf meal.
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Table 1. Proximate composition (%) of Chromolaena odorata leaf meal |
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Nutrient |
Composition |
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Dry matter |
87.4 |
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Crude protein |
18.7 |
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Crude fibre |
11.7 |
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Ether extract |
1.01 |
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Ash |
3.63 |
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Nitrogen free extractives |
65.0 |
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Gross energy, kcal/g |
3.73 |
Figure 1 shows the external morphology of the plant.
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Four isonitrogenous and isocaloric diets were formulated with graded levels of Cromolaena odorata leaf meal at 0%, 2.5%, 5% and 7.5% level of inclusion. The diets were designated Cromolaena odorata (0%), C.O.(2.5%), C.O.(5.0%) and C.O.(7.5%) respectively with C.O.(0%) without the inclusion of Cromolaena odorata leaf meal serving as the control diet. Table 2 shows the gross composition of the experimental diets. White maize variety was used as the main energy source of the four diets throughout the duration of the experiment. At the eighth month of laying, 36 birds were selected out of 2000 Hyperco strains for use in this study. The birds were randomly allotted into individual battery cage compartment with 3 birds per replic
After
egg weight determination, a total of 72 eggs (6 eggs per replicate) were broken
out on a flat-surfaced white tile measuring 45cmx45cm and height of the albumen
was determined with a tripod micrometer as described by Oluyemi and Roberts
(2000). The yolk colour was scored with the aid of Roche Yolk Colour Fan
graduated into 15 different colour units. After egg breakerage, the two egg
membranes were pulled off the shells and the shells so treated were air-dried
for a day after which the thickness of the shell was measured with a micrometer
screw gauge. The values obtained were used to compute the average shell
thickness per replicate. The air-dried shells were also weighed to determine the
average shell weight and percentage shell per replicate. The Haugh’s unit was
calculated from the values obtained from albumen height and egg weight by
employing the formula given by Haugh (1937):
Haugh’s unit = 100log (H+7.57-1.7W0.37)
Where:
H =
observed albumen height in millimetres and
W = observed egg weight in grammes.
Data obtained on the egg parameters were subjected to one-way analysis of variance using SPSS version15 statistical package. Where there is significant differences among the means, mean separation was done with Duncan multiple range test (DMRT) of the same statistical package.
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Table 2. Gross composition (%) of the experimental diets |
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Ingredient |
Inclusion level of Cromolaena odorata leaf meal |
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C O, 0% |
C O, 2.5% |
C O, 5.0% |
C O, 7.5% |
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Maize |
56.0 |
56.0 |
56.0 |
56.0 |
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Groundnut cake |
10.5 |
10.6 |
10.6 |
10.6 |
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BDG |
20.0 |
17.5 |
15.0 |
12.5 |
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C. O. Leaf meal |
0.00 |
2.50 |
5.00 |
7.50 |
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Fish meal |
2.50 |
2.50 |
2.50 |
2.50 |
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Bone meal |
6.00 |
6.00 |
6.00 |
6.00 |
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Oyster shell |
4.00 |
4.00 |
4.00 |
4.00 |
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Layers’ premix* |
0.50 |
0.50 |
0.50 |
0.50 |
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Salt |
0.50 |
0.50 |
0.50 |
0.50 |
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Total |
100 |
100 |
100 |
100 |
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Crude protein |
15.0 |
15.0 |
15.0 |
15.0 |
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ME, kcal/g |
2.63 |
2.66 |
2.68 |
2.64 |
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*Layers premix: A Pfizer supplement supplying the following per kilogramme of ration: Vitamin A-800I.U., Vitamin D3-1473 I. C. U., Riboflavin-4.20mg, Pantothenic acid-5.0mg, Nicotinic acid-20.0mg, Folic acid-0.5mg, Choline-300mg, Vitamin B12-0.01mg, Vitamin K-2.0mg, Vitamin E-2.5I.U., Manganese-56.0mg, Iodine-1.0mg, Iron-20.0mg, Copper-10.0mg, Zinc-50.0mg and Cobalt-1.25mg. BDG = Brewers’ dried grains. |
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The performance and egg quality characteristics of birds fed on the four diets were as presented in Table 3.
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Table 3. Performance and egg quality characteristics of laying hens fed graded levels of Chromolaena odorata leaf meal |
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Parameters |
Inclusion level of Cromolaena odorata leaf meal |
SEM |
P |
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C O, 0% |
C O, 2.5% |
C O, 5.0% |
C O, 7.5% |
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Egg weight, g |
59.1 |
63.9 |
58.4 |
60.0 |
2.13 |
>0.05 |
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% hen-day production |
59.2 |
54.5 |
64.3 |
60.1 |
4.76 |
>0.05 |
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% hen-housed production |
59.2 |
54.5 |
64.3 |
60.1 |
4.76 |
>0.05 |
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Total egg production |
299 |
275 |
324 |
303 |
7.29 |
>0.05 |
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Shell thickness(mm) |
0.33 |
0.34 |
0.34 |
0.34 |
0.02 |
>0.05 |
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Yolk colour score(RYCF) |
1.00d |
4.75c |
6.50b |
8.58a |
3.02 |
<0.05 |
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Haugh’s unit |
73.4 |
72.6 |
78.7 |
76.6 |
0.19 |
>0.05 |
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Albumen height, mm |
5.47 |
5.68 |
6.23 |
6.03 |
0.56 |
>0.05 |
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Shell weight, g |
5.89 |
6.36 |
5.85 |
5.98 |
0.08 |
>0.05 |
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% shell |
9.96 |
9.96 |
9.96 |
9.97 |
0.43 |
>0.05 |
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a,b,c,d = means in the same row but with different superscripts are statistically significant(P<0.05). RYCF = Roche Yolk Colour Fan, P = Probability that differences are due to chance. |
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The average weight of the eggs was not significantly affected by the dietary levels of Cromolaena odorata leaf meal. C.O. (2.5%) had the heaviest eggs (63.9g) while C.O. (5.0%) had the lightest eggs (58.4g). Similarly the shell thickness, Haugh’s unit, albumen height, shell weight and percentage shell were not significantly (P>0.05) affected by the levels of Cromolaena odorata leaf meal in the diets, but there was a slight improvement of the Cromolaena odorata diets over the control diet in all these parameters except in shell weight and Haugh’s unit where the control diet performed better than C.O.(5.0%) (5.89g versus 5.85g) and C.O.(2.5%) (73.4g versus 72.6g) respectively.
That the egg weight did not show any significant variation among the treatment means is suggestive of the equi-proteinous and iso-caloric nature of the diets and the fact that the birds were of the same age, since egg weight is more of a function of the age of the birds and the quality of their feed (Abeke 1997).
Similar trend observed on the egg shell thickness showing a slight improvement with dietary inclusion of Cromolaena odorata leaf meal could therefore be an indication that calcium absorption and utilization, rather than being compromised in the laying hens, was improved with dietary Cromolaena odorata inclusion. This same trend was also reflected in the percentage shell content that was slightly improved over the control with the inclusion of Cromolaena odorata leaf meal.
The yolk colour score as determined by the Roche Yolk Colour Fan (RYCF) as statistically significant (P<0.05) among the treatment means. The economic significance of this as far as egg quality is concerned is that even at the lowest level of dietary inclusion of Cromolaena odorata in this trial (2.5% level), the minimum acceptable standard for yolk colour score (i.e. 4.0 of the RYCF) by individual consumers and the pastry industries, as reported by Ogundipe et al (1992) had been attained. This minimum standard was far exceeded at 5% and 7.5% levels of inclusion i.e. 6.50 and 8.58 RYCF scores respectively.
From the results obtained for the egg quality characteristics of dietary inclusion of Cromolaena odorata leaf meal, it can be concluded that utilization of Cromolaena odorata in layers diet even at the highest level of incorporation in this trial (7.5%), would not compromise egg quality characteristics like egg weight, shell thickness, albumen height and Haugh’s unit. The significant impartation of deeper yolk colouration on the eggs with increasing level of Cromolaena odorata strongly supports its utilization in layers’ diets as egg yolk colourant in order to obviate the huge capital flight incurred annually by Nigeria on the importation of highly expensive synthetic egg yolk colourants to meet the needs of the pastry and confectionery industries. Using the leaves of this erstwhile “obnoxious weed” as egg yolk colourant could also mark a departure from its total eradication as occasioned by its environmental implication to its subtle cultivation for the benefit of mankind.
Abeke F O 1997 Response of laying hens to dietary levels of sheep manure. M.Sc. Thesis, Ahmadu Bello University, Zaria. Nigeria Pp.1-81.
Abeke F O, Ogundipe S O, Sekoni A A and Adeyinka I A 2008 Effects of dietary levels of sun-dried sheep manure on productive performance and egg quality parameters of Shika-brown layers. Nigerian Journal of Animal Production 35(2): 195-201
Akinmoladun A C and Akinloye O 2007 Effect of Cromolaena odorata on hypercholesterolemia-related metabolic imbalances. Proc. Akure-Humbold Kellog/3rd SAAT Annual Conference, FUTA, Nigeria, 16-19 April 2007: 287-290.
Aro S O 1990 The effects of Siam weed leaf meal (Chromolaena odorata) on the performance, egg quality characteristics, nutrient utilization, haematological and biochemical indices of layers. M.Sc. Thesis, Department of Animal Science, University of Ibadan, Ibadan-Nigeria. Pp. 1-84.
Fasuyi A O, Fajemilehin S O K and Aro S O 2005 Nutritional potentials of Siam weed (Chromolaena odorata) leaf meal (SWLM) on laying hens: Biochemical and haematological implications. Pakistan Journal of Nutrition 4(5): 336-341 https://eprints.kfupm.edu.sa/95121/1/95121_1.pdf
Haugh R R 1937 The haugh unit for measuring quality of eggs. Egg and Poultry Magazine 43: 552-55
Iwu M M 1993 Handbook of African medicinal plants. CRC Press Inc. Beca Raton. Pp. 181-182.
Odugbemi T 2006 Outlines and pictures of medicinal plants from Nigeria. University of Lagos Press, Lagos, Nigeria, Pp. 1-283.
Ogundipe S O, Sa’adu G, Bale, J O, Aduku A O and Balogun T F 1992 Utilization of animal manure in poultry diets. A seminar paper presented at NAPRI, Shika-Zaria, Nigeria.
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Sajise P E, Palis R R, Norcio N V and Lales J S 1974 The biology of Cromolaena odorata (L. King and Robison) 1. Flowering behaviour, pattern of growth and nitrate metabolism. Philippian Weed Science Bulletin 1: 17-24
Received 22 June 2009; Accepted 8 July 2009; Published 1 October 2009
