Livestock Research for Rural Development 16 (6) 2004

Citation of this paper

Performance, carcass and organ characteristics of finisher broilers fed graded levels of raw Napoleona imperialis seed meal

M C Uchegbu, I C Okoli, C E Anyanwu, E B Etuk, B O Esonu and A B I Udedibie

Department of Animal Science and Technology, Federal University of Technology, PMB 1526, Owerri, Imo State, Nigeria. ,


A 28-day feeding trial involving 192, 4-week old Anak finisher broilers was carried out in a completely randomized design to evaluate the effect of raw Napoleona imperialis seed meal at 0, 5, 10 and 15% dietary levels on the performance, carcass and organ characteristics of finisher broilers. The raw Napoleona imperialis seed meal replaced 0, 8.33, 16.7and 26.7% of maize in the finisher broiler diets. Data was collected on feed intake, growth rate, feed conversion ratio and carcass and organ characteristics.

Feed intakes of the birds on 0, 5 and 10% Napoleona imperialis seed meal inclusion were similar and higher than the group on 15% inclusion. Growth rate and feed conversion of the 0 and 5% dietary groups were superior to the groups on 10 and 15% seed meal inclusions. The birds on 15% seed meal inclusion exhibited lower percentage dressed weight, heart, kidney and spleen weights.

The results suggest that 5% inclusion level of Napoleona imperialis seed meal could be used without any deleterious effects on finisher broilers. However there is the need to subject Napoleona imperialis seed to processing that will enable its utilization in broiler feeds at levels exceeding 5% inclusion.

Key words: carcass and organ characteristics, finisher broilers, Napoleona imperialis, performance


Napoleona imperialis is an evergreen non-timber plant that grows abundantly in bush fallows, secondary bushes and marginal lands in most of the tropical humid zone of West Africa (Koppel 1990). Different parts of the plant are used for different purposes in the region including mulching and fodder (leaves and twigs), and firewood, chewing stick and ethno-medicine (stem and root) (Osei-Owusu 1981; Okafor and Fernandez 1987). Humans consume the juice from the fruits and pods and the seeds are discarded. The seeds have very low human food preference or any industrial use as of now and could therefore form an alternative feed ingredient for livestock production.

Recently, Uchegbu et al (2002) studied the proximate composition of ripe and dried raw Napoleona imperialis seed meal and found the seed to contain 90.5 g/kg-1 crude protein.  Iheukwumere and Okoli (2002) and Iheukwumere et al (2002) fed the raw dry seed to weaner rabbits and found that at 15% dietary inclusion the seeds had deleterious effects on performance, hematology and serum criteria, while at 5% inclusion the rabbits did not show any negative effect on similar parameters.

Various published reports have highlighted the negative effects of the use of unusual ingredients on some performance parameters of experimental animals as a result of factors such as nutrient imbalance, improper metabolism, presence of anti-nutritional factors and toxic elements in the ingredient (Emenalom 1996; Awosanya et al 1999; Esonu et al 2001). Current research in our laboratory includes identification of the anti-nutritional factors and toxic elements that may be present in raw Napoleona imperialis seeds. The objective of this study was to ascertain the effect of raw Napoleona imperialis seed meal as a feed ingredient on the performance, carcass and organ characteristics of finisher broilers.

Materials and methods

Seed preparation and analysis

Ripe Napoleona imperialis pods were collected from bushes around the Federal University of Technology Oweri and adjoining communities namely Obinze, Mgbirichi and Ihiagwa, all in Imo state, south-eastern Nigeria. The pods were opened with a knife and the seeds extracted, sun-dried for seven days and milled to produce the seed meal. Proximate analysis was conducted using standard methods (AOAC 1990) (Table 1). Metabolizable energy (ME) was determined based on the proximate composition using the prediction equation outlined by Morgan et al (1975).

Table 1. Proximate composition of Napoleona imperialis seed meal



Crude protein


Crude fiber


Nitrogen free extract


Ether extract


Dry matter




ME, kcal/kg*


* Determined according to Morgan et al (1975)

Thereafter, four broiler finisher diets were formulated to contain raw Napoleona imperialis seed meal at 0, 5, 10, and 15%, respectively. This replaced 0.00, 8.33, 16.7 and 26.7% of maize in the diet (Table 2).

Table 2. Calculated chemical composition (% in DM) of the diets


Napoleona imperialis seed meal, %





Crude protein





Crude fiber





Ether extract





ME, kcal/kg





Feeding trial

Ninety-six 4 weeks-old Anark broilers that had been fed a standard diet during the starter phase were divided into 4 groups of 24 birds each and randomly assigned to the four treatment diets in a completely randomized design (CRD) experiment. Each treatment group was further sub-divided into 4 replicates of 6 birds each. Feed and water were provided ad-libitum. Feed intake was recorded daily and the birds were weighed weekly. The feeding trial lasted for 28 days.

Carcass and organ weight evaluation

On the 29th day of the trial, four birds (2 male and 2 female) per replicate group were randomly selected for carcass and organ weight evaluation after fasting them over night. The birds were weighed, slaughtered and allowed to bleed thoroughly according to the method recommended by Odunsi et al (1999). Thereafter, the carcasses were de-feathered, cleaned, dissected and eviscerated. The heart, liver, gizzard and spleen were removed and weighed after inspecting them for gross changes. The different parts and organs were expressed as percentages of the initial body weight of the birds.

Statistical analysis

Data collected were subjected to analysis of variance (ANOVA) (Steel and Torrie 1980). Where significant treatment effect was detected, means were separated using the Duncan New Multiple Range Test as outlined by Obi (1990).



Feed intake did not differ among the groups on 0, 5, and 10% dietary levels of Napoleona imperialis seed meal (Table 3). However, birds on 15% dietary inclusion, had lower feed intake from those on 0, 5 and 10% inclusion levels. The growth rates and feed conversion rates of the birds on 0 and 5% diets, were similar and better than those on 10 and 15% Napoleona diets.

Table 3. Effect of different dietary levels of Napoleona imperialis seed meal on mean  performance criteria of finisher broilers


Napoleona imperialis meal, %






Initial body wt, kg






Final body wt, kg






Growth rate, g/day






Feed intake, g/day






Feed conversion, g feed / g wt. gain






Mortality, %






ab means in the same row with different super scripts are different (p<0.05)

Carcass and organ weight evaluation

There were no differences between the percentage weights of liver, gizzard and kidney of birds on the control diet, and those on the different treatment diets. However, values for percentage heart  were lower in birds on 0 and 5% Napoleona imperialis compared with 10 and 15% inclusion. Similarly, the spleen weight of birds on 15% seed meal inclusion diet was significantlyhigher than those of other treatment birds. The proventriculus and intestine harvested from birds on the control diet were significantly heavier than those harvested from birds on any of the treatment diets. The dressed weight and breast muscle of birds decreased with increasing level of Napoleona imperialis inclusion in the diets and were significantly lower than the rest at 15% inclusion.

Table 4. Mean values for carcass and organ characteristics of finisher broilers fed graded levels of raw Napoleona imperialis seed meal


Napoleona imperialis meal, %






Weight as % of initial live weight      

Dressed carcass










































Breast muscle






Drum stick












Intestine, kg






ab means in the same rows with different superscript are different (p,0.05)


The proximate composition of the Napoleona imperialis seed meal reported here, is similar to the earlier results published by Uchegbu et al (2002). The crude protein value while superior to that of maize, compared favorably with that of chicken pea and wheat bran (Aduku 1993; Olomu 1995). The predicted methabolizable energy value of the seed meal on the other hand, was much lower than that published for maize (Maynard et al 1979; Obioha 1992).

There was a general increase in feed intake as the dietary level of Napoleona imperialis seed meal increased up to 10% inclusion. This reflected the dilution of energy concentration arising from increasing levels of Napoleona imperialis inclusion as the birds had to increase their feed intake to compensate for the low concentration of available energy (Hill and Dansky 1954; Esonu et al 1997). However, the significant decline in feed intake at 15% dietary inclusion of the seed meal could perhaps be attributed to the presence of some antinutritional factors, which are thought to be prevalent in most unconventional feedstuffs (D'Mello 1982).

The depression in growth rate, which resulted in a high FCR among the birds on 10 and 15% seed meal inclusion diets, and the inconsistency in feed intake values for these treatments suggest poor utilization of these diets. Experience has also shown that at higher inclusion levels, unconventional feedstuff may alter the texture, color, taste and odor of diets. Feed consumption and ultimately utilization might be affected by each of the above factors independently or in combination (Ander 1992; Nir et al 1994; Odunsi et al 1996). Specifically, presence of antinutritional factors and low ME value may not be ruled out as further contributory factors to the depressing effects of higher inclusions of raw Napoleona imperialis seed meal in diets of finisher broilers (D'Mello 1982; Amaefule and Obioha 2001). Survival ratio of the birds suggests that finisher broilers could tolerate Napoleona imperialis seed meal in their diets. For any of the parameters considered, however, birds on the 5% diet consistently showed better performance data than those feeding on the 10 and 15% seed inclusion diets.

Since carcass yield is an indication of the quality and utilization of the ration (Bamgbose and Niba 1998), it would seem that birds on the 15% seed meal inclusion diet poorly utilized their feed as evidenced by their significantly lower dressed weight, breast muscle and drum stick. Significantly, higher values were also observed for weights of proventriculus and intestine of all the groups on Napoleona imperialis seed diet. This could be due to additional bulk and greater volume of digester staying in the gastrointestinal tract during enzymatic digestion (Savory and Gentle 1976; Longe and Fagbenro-Byron 1990; Ander 1992). Furthermore, it has been observed that structural carbohydrates in monogastric diets specifically have a mechanical effect on intestinal wall and cause the gastro-intestinal tract to increase and thicken (Thorburn and Wilcox 1985). As the level of the test seed meal increased, the percentage shank weight also increased indicating poor growth and performance. The significantly higher values observed with heart, liver and spleen of birds on 15% inclusion diet could probably be due to higher physiological activities by these organs triggered by the presence of antinutritional factors and their concomitant effects.


From this study, it would appear that 5% inclusion level of raw Napoleona imperialis seed meal could be used in finisher broiler diets without any deleterious effect on performance. Further research is necessary to determine how to increase the nutritive value of Napoleona imperialis seed meal for monogastric animals in view of its relative and abundance and ease of collection.


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Received 14 March 2003; Accepted 27 April 2004

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