Abstract: Background and Objective: Indigenous plants remain green at critical times of the year and produce large quantities of year round fodder, which is regarded as unconventional feed sources in tropical countries like Nigeria. This study evaluated the physico-chemical characteristics of leaf meals derived from Ficus microcarpa, a domesticated browse plant at Nnobi community, southeastern Nigeria. Materials and Methods: The three villages in the community namely Awuda (Sample A), Ebenesi (Sample E) and Ngo (Sample N) were purposively selected for the study in order to generate representative data for the community. Fresh foliage from three stands of F. microcarpa at each village was collected and air-dried by spreading them under shed every day for about 6-8 days and thereafter oven dried until they became crispy and then milled to produce F. microcarpa leaf meals (FMLM). The leaf meals were analyzed for their physicochemical values. Results: Results should that FMLM was rich in Fe and Zn. The order of micro mineral concentration was Fe>Mn>Cr>Zn>Cu>Ni. Conclusion: The FMLM is therefore relatively rich in crude protein and energy, digestible fibers and essential minerals. Feeding trials incorporating the leaf meal are recommended in order to evaluate its true nutrient value.
INTRODUCTION
With the increasing demand for livestock products as a result of rapid growth in the world economies and shrinking land area, future hope of feeding the millions of people and safeguarding their food security will depend on the better utilization of hitherto neglected feed resources1 and this has over the past few decades rekindled research interest in the use of indigenous tropical browse plants as sources of nutrients for livestock2,3. Although the diversity and nutritional values of these indigenous browse species may be well known to local livestock farmers4,5, limited published information exists on the physicochemical properties associated with their use at different farming locations.
Indigenous fodder trees and shrubs remain green at critical times of the year5 and produce large quantities of year round fodder, which is regarded as unconventional feed sources in tropical countries like Nigeria. The year round availability of these unconventional fodders when incorporated to ruminant diets planning help to tackle the effects of poor nutrition which usually manifest as loss of weight and conditions, reduced reproduction capacity, increase mortality rate, poor carcass quality among ruminants reared in many tropical environments6. Proper evaluation of the production characteristics of such economic browse plants like F. microcarpa would provide reliable data to farmers and development workers on the social, nutritional and toxicological issues associated with the plant's promotion as a browse of promise in the study area and beyond.
The use of tree fodders as feed is usually limited by their poor intake, high fibre content and in some cases the presence of toxic factors or metabolic inhibitors such as cyanogens, alkaloids, saponins and tannins, low digestibility and low nutrient content and subsequent low animal performance7. There is, therefore, the need to properly assay the nutritional, physicochemical and toxicological potentials of novel candidate tropical feedstuffs such as Ficus microcarpa before they could be promoted as fodder of commercial value in animal production. In recent times, however, a large number of researches have focused on phytochemicals as cheap sources of novel chemicals for animal production and human health/nutrition. Plants with anti-oxidant properties have received special research attention mainly due to their phenolic compounds8, which are beneficial in many applications in animal nutrition9. Therefore, identification and such characterization of the potential value of indigenous browse plants could lead to the improvement of the economic value of local plants, thereby encouraging their development for improved rural income.
However, most of the available information on indigenous browses of Nigeria are on their proximate compositions with little or no information on the physical and phytochemical characteristics of their leaf meals needed to properly characterize such animal feed resources10,11. Several studies have however shown that physical properties of novel feedstuffs such as their bulk density, water holding capacity and particle size among others exhibit greater influence on feed intake than their nutrient compositions12,13. There is, therefore, the need to include such physical characteristics analysis as part of the screening protocol for lesser-known but novel feedstuff of local or international application12.
According to Okoli et al.3 and Udedibie14, there are currently no properly developed protocols for ranking and selecting indigenous browse plants of high nutritional potential out of hundreds of candidate plants species available in southeastern Nigeria. Development of such ranking and selection protocol could eliminate some of the frustrations experienced with many trial materials, which usually arise from poor or non-existent reliable selection protocol. In earlier studies Okoli et al.2,3,15 used a combination of indigenous knowledge (IK) and proximate profiles as tools for selecting plants of animal production potentials in southeastern Nigeria and concluded that apart from generating clues on candidate research materials, such studies could promote useful development concepts and bio-cultural diversity.
The objective of this study is to determine the physicochemical characteristics of Ficus microcarpa, a locally domesticated ruminant browse at Nnobi, in Idemili south Local Government Area of Anambra state, southeastern, Nigeria.
MATERIALS AND METHODS
Study area: The study was carried out at Nnobi community in Idemili south Local Government Area (LGA), Anambra Central Agricultural zone of Anambra state, Nigeria in the months of April-July, 2016. The vegetation is the rainforest type, with a tropical humid climate characterized by two distinct seasons, the rainy and the dry seasons. Livestock farming, especially small ruminant keeping and backyard poultry are popular. The farmers commonly utilized Ficus microcarpa (Ogbu), Ricinodendron heudelotii (Okwe), many abundant twigs, weeds, grasses and kitchen wastes for feeding small ruminants2,16.
Nnobi community was purposively selected for the study because of the traditional practice of planting and feeding Ficus microcarpa (Fig. 1) to animals in the community and also due to the active participation of the indigenes in small ruminant rearing17.
| Fig. 1: | A Ficus microcarpa tree standing in a compound in the study area |
The three villages in the community were also purposively selected for the study in order to generate representative data for the community. Many households/farmers were preliminarily surveyed but only three households/farmers were randomly selected from each village for the final study, thus, giving 15 households/farmers that constituted the sample size for the study.
Sample collection and preparation: Fresh foliage from three stands of Ficus microcarpa at each study village were collected and were used for the study. Identification of the sampled plant was made at the Department of Forestry and Wildlife Technology, Federal University of Technology Owerri (FUTO), Imo state, Nigeria. The leaves sampled from each village were plucked and air-dried by spreading them under shed every day for about 6-8 days while retaining the greenish coloration16. The samples were further dried in the oven until they became crispy to aid milling. The dried leaf samples were ground with hammer mill through a 1 mm screen to produce their respective leaf meals and were collected in sealed polythene bags, labeled and ready for physical and phytochemical analysis.
Physicochemical analysis: The analyses were carried out at the School of Agriculture and Agricultural Technology Laboratory of FUTO for their Bulk Density (BD), Water Holding Capacity (WHC), Specific Gravity (SG), proximate composition, metabolizable energy, fiber fractions and minerals. The method described by Makinde and Sonaiya18 and modified by Omede11 were used to determine the BD and WHC values, SG was calculated as the ratio of the BD of a known mass of the experimental sample to the density of water for the sample11.
The proximate analysis was carried out to determine the Moisture Content (MC), Crude Protein (CP), Ether Extract (EE), Crude Fiber (CF), Nitrogen Free Extract (NFE), Total Ash (TA) and Gross and Metabolizable energy according to the methods of AOAC19. All the proximate values were reported in percentages. The calorific measurements of samples for gross energy analysis were done with Cal 2 K, C1.7 bomb calorimeter. The gross energy was determined according to AOAC19 using the digital CAL-2K Isothermal Automatic Bomb Calorimeter.
The fiber fractions such as Neutral Detergent Fibre (NDF), Acid Detergent Fiber (ADF), Acid Detergent Lignin (ADL), cellulose and hemicellulose (HEM) were determined according to the methods described by AOAC19. Mineral composition analysis (micro and macro-element) was performed with an Atomic Absorption Spectrophotometer (AAS), Bulk scientific, model 210 VGB to determine the following minerals; Ca, K, Na, P, Mg, Mn, Fe, Cu, Zn, Co, Cr, Pb and Ni according to the methods of AOAC19 using the Atomic Absorption Spectrophotometer (Bulk Scientific, 205).
Statistical analysis: Data generated were subjected to descriptive statistics such as means, Standard Deviation (SD) and Coefficient of Variation (CV) to establish the reference values of the different parameters analyzed20.
RESULTS
Physical characteristics of F. microcarpa leaf meal: Table 1 showed the Loose Bulk Density (LBD), Packed Bulk Density (PBD), Specific Gravity (SG) and Water Holding Capacity (WHC) of the FMLM samples. Sample N recorded the highest packaged bulk density which was significantly different (p<0.05) from the ones obtained from sample A and E. Sample N also recorded the highest loose bulk density which was also significantly different (p<0.05) from the values obtained from samples A and E. Sample A recorded the highest WHC which was significantly higher (p<0.05) than that of sample E. Sample N also recorded the highest value of specific gravity, which is also significantly different (p<0.05) from value obtained from sample E but not significantly different from value recorded in Sample A.
Proximate composition of Ficus microcarpa leaf meal: Table 2 showed the proximate composition results of FMLM samples from different locations at Nnobi. Sample E recorded the highest level of dry matter DM and was significantly higher (p<0.05) than the value recorded in sample N but similar to the value obtained in sample A (p>0.05). Sample E had significantly higher (p<0.05) NFE and ME than those on sample N but similar to those on sample A. Sample E recorded the highest CP value, which was significantly higher (p<0.05) than the sample A value but statistically similar (p>0.05) to the value recorded in sample N. The result also showed that sample E had significantly higher ether extract value (p<0.05) than sample N but similar to that of sample A (p>0.05). Sample N recorded significantly higher CF content than sample A (p<0.05) but was similar to sample E (p>0.05). Sample N recorded significantly higher ash value (p<0.05) than sample E but similar values with sample A (p>0.05) while sample E recorded a higher nitrogen free extract value of 41.25% (p<0.05) than sample N but similar to the value recorded in sample A (p>0.05). Additionally, sample E had higher ME value than sample N (p<0.05) but was statistically similar to sample A value (p>0.05). Moisture content was significantly (p<0.05) influenced by the locations.
Fiber fractions in Ficus microcarpa leaf meal: The results of the fibre fractions were presented in Table 3. Sample E recorded significantly higher NDF value than sample A (p<0.05) but similar to sample N, which was also similar to sample A (p>0.05). Also, sample N recorded a significantly higher ADF value than sample E (p<0.05) but was similar to the value recorded in sample A (p>0.05). Results revealed that sample N had significantly higher ADL value (p<0.05) than sample E but similar to sample A value (p>0.05). Sample E recorded significantly higher cellulose value (p<0.05) than sample A but similar to the value recorded in sample N (p>0.05). Again, sample E recorded significantly higher (p<0.05) value than sample N but was similar to the value recorded in sample A.
Mineral compositions of Ficus microcarpa leaf meals: Data on mineral compositions of MFLM are shown in Table 4. Sample A recorded significantly higher calcium and phosphorus values and lower sodium and magnesium values than sample E (p<0.05), while sample N also recorded significantly higher potassium value than sample E (p<0.05). Generally, sample N had statistically similar Calcium (Ca), Sodium (Na), Phosphorus (P) and Magnesium (Mg) values (p>0.05) with samples A and E (p>0.05).
| Table 1: | Physical characteristics of Ficus microcarpa leaf meal |
Means within the same rows show that means are significantly different (p<0.05), Sample A: Awuda, Sample E: Ebenesi, Sample N: Ngo, SD: Standard deviation, SEM: Standard error of the mean, CV: Coefficient of variation | |
| Table 2: | Proximate and metabolizable energy compositions of Ficus microcarpa leaf meal |
Means within the same rows show that means are significantly different (p<0.05), Sample A: Awuda, Sample E: Ebenesi, Sample N: Ngo, SD: Standard deviation, SEM: Standard error of the mean, CV: Coefficient of variation | |
| Table 3: | Fiber fraction of Ficus microcarpa from different locations at Nnobi |
Means within the same row shows that means are significantly different (p<0.05), Sample A: Awuda, Sample E: Ebenesi, Sample N: Ngo, SD: Standard deviation, SEM: Standard error of the mean, CV: Coefficient of variation | |
| Table 4: | Macro-mineral concentrations (mg kg–1) of Ficus microcarpa leaf meal |
Means within the same rows show that means are significantly different (p<0.05), Sample A: Awuda, Sample E: Ebenesi, Sample N: Ngo, SD: Standard deviation, SEM: Standard error of the mean, CV: Coefficient of variation | |
| Table 5: | Micro-mineral composition (mg kg–1) of Ficus microcarpa leaf meal from Nnobi |
Means within the same rows show that means are significantly different (p<0.05), Sample A: Awuda, Sample E: Ebenesi, Sample N: Ngo, SD: Standard deviation, SEM: Standard error of the mean, CV: Coefficient of variation | |
| Table 6: | Calcium/phosphorus and sodium/potassium ratios of Ficus microcarpa from Nnobi |
Means within the same rows show that means are significantly different (p<0.05), Sample A: Awuda, Sample E: Ebenesi, Sample N: Ngo, SD: Standard deviation, SEM: Standard error of the mean, CV: Coefficient of variation | |
Table 5 showed the micro-mineral composition of F. microcarpa leaves from different locations at Nnobi. Sample A had significantly lower (p<0.05) manganese (Mn) concentration than sample E, while sample N recording a significantly higher iron (Fe) value than sample A (p<0.05) but similar to sample E (p>0.05). Sample N had significantly higher zinc (Zn) value than sample E value. Chromium (Cr) and nickel (Ni) values in sample E were lower (p<0.05) than in sample A but similar to those on sample N (p>0.05). Copper (Cu) on sample E recorded significantly (p<0.05) higher value than in sample N.
The calcium to phosphorus and sodium to potassium ratios of the study plant from different locations were shown in Table 6. Sample E recorded a significantly higher Na/K ratio value (p<0.05) than the samples A and N.
DISCUSSION
Usually, feedstuffs have nutritional characteristics21, which could be divided into the biophysical and biochemical components that determine nutrient uptake and availability, respectively10,22. The feed value of forage is, however, a function of its nutrient content digestibility, its palatability (which determines its consumption level) and the associative effects of other feeds23. Furthermore, the nutritional characteristic of a finished ration is an aggregation of the proximate, physical and toxicological characteristics of the individual ingredients used in compounding the ration. Therefore, a proper understanding of all these component characteristics in all feed raw materials is imperative10,21.
Sample N had significantly high loose bulk density than those on samples E and A which was similar to the value reported for Microdesmis puberula leaf meal by Omede11. Even though there were statistical differences across data obtained from the different samples, their coefficient of variation values at the range of 0.03-0.20 indicated narrow margins between sample values implying that the mean values could be trusted as the representative physical characteristic values for FMLM obtained from the study area. Sample A recorded the highest WHC value of 440.00% which was significantly higher than that of sample E indicate that the dry leaf meal of the sampled plant will absorb a reasonable amount of water when included in the diets of monogastric animals and ruminants12. The CV value across sample measurements for WHC was narrow indicating that the samples have similar WHC attributes. The present high WHC results is probably a pointer to significant levels of non-starch polysaccharides (NSPs) contents of the leaves as a result of their maturity12. Since the specific gravity values in this study were derived mathematically from the BD values, the recorded similar trends of SG and BD of the test materials was expected.
It was observed that samples that recorded higher BD values also recorded higher specific gravity and lower WHC values, while samples that recorded lower BD values recorded low SG and high WHC values. Low BD values suggested high fibrous matter, while low SG implies low retention time and faster passage of feed particles in and through the GIT respectively24. Kyriazakis and Emmans25 noted that WHC is a good predictor of feed intake in pigs compared to feed digestibility and dietary fibre content. This major effect of WHC on digestion is due to the ability of the NSPs in the feedstuff to hold considerable quantities of water that could increase bulk and passage rate of digesta26. High WHC obtained from the present study, therefore, indicate that the FMLM would absorb high volumes of water when used in feeding ruminant or poultry.
The loose BD values obtained in this study agreed with the 0.02 g m–3 reported by Omede et al.12 for M. puberula leaf meal. The loose BD values were much lower than the 0.59, 0.42 and 0.41 g mL–1 values obtained by Udedibie14 in Gongronema latifolium, Mucuna pruriens and Garcinia kola leaf meals, respectively. The packed BD value is however similar to that of G. latifolium and G. kola but much higher than that of M. pruriens14. The 0.61 g water/g feed WHC reported for M. puberula leaf meal is higher than the mean 425.73±12.67% obtained for FMLM in this study, implying that the M. puberula leaf meal contained more NSPs than the FMLM analyzed in this study. Udedibie14 reported much lower WHC values of 245.45 and 250% in G. latifolium and M. pruriens, respectively but similar value of 440% in G. kola leaf meal. Omede et al.12 also reported that Particle Size (PS) modification of a leaf meal could alter its BD and WHC attributes. For example, when the particle size of M. puberula leaf meal was reduced from unmodified to <1.00 mm PS, the WHC increased from 0.61-5.50 g water/g feed, a 901.64% increase in WHC. There is, therefore, the need to properly characterize the WHC attributes of FMLM, especially as influenced by PS of the leaf meal.
Results of the proximate analysis are extensively employed in research and industry for quick estimation of nutrient potentials of feedstuffs. Although such results may not give a true indication of the nutritive value of a feed, they supply clues in research to plants of potential value for further in vitro or in vivo studies16,27,28. Proximate analysis is specifically useful in screening the potentials of the array of tropical browse plants utilized by indigenous farmers for ruminant feeding29. Standard Deviation (SD) values across DM, MC, CP, EE, CF and TA were narrow indicating the reliability of these mean values as reference values for the leaf meal. However, the CV values were low (0.03-0.23), indicating that the mean value may serve as a reliable reference value for the leaf meal in the study area. Dry Matter (DM) content of FMLM as obtained in the current study was much higher than the mean dry matter value of 65.10% reported by Carew et al.30 for browse plants in the derived savannah area of Nigeria but fell within the reference values of tropical plant leaves used in livestock feeding as reported by Anunobi31. Udedibie14, however, obtained a slightly higher range of values in some selected leaf meals from southeastern Nigeria. The differences in the dry matter content of the browses could be due to the processing methods such as drying at different room temperatures before laboratory analysis. The variability in the nutrient content of fodder trees and shrubs have also been attributed to the state of hydration (fresh, wilted and dry) and drying procedure32,33. Oguntona34 had ascribed wide variation in the values of nutrient content of leafy vegetables to variations in nutrient and fertilizer status of the soil on which the crops were grown, sample preparation procedure before analysis and analytical procedure which may vary in technique and quality. A high DM content of plants is obviously an advantage as it would serve as a veritable source of nutrients and would assist in meeting the bulk needs of ruminant animals fed with the browse, while relatively; high moisture content of any sample suggests that it stands the risk of microbial deterioration and spoilage during storage.
The high CP value of suggests that FMLM will serve as a good source of protein diet for small ruminants since Nastis and Malechel35 reported an acceptable range of 7-14% CP for ruminants. Devendra and McLeroy36 reported 11% CP to be ideal for normal weight gain in sheep and goats. Le-Le Houerou37 reported a mean CP of 12.5% for tropical browses, while Onwuka38 reported 15.87% for browses of Southern Nigeria. Udedibie14 reported much higher CP (24.46 and 20.73%) in G. latifolium and M. pruriens, respectively but similar value the reported in G. kola leaf meals. Okoli et al.16 also reported a CP value of 18.23% for Ricinodendron heudelotii, a plant closely associated with F. microcarpa in the cafeteria feeding of small ruminants at the study area. The result was also similar, though slightly lower than the report of Njidda39 for the CP content of Ficus polita, Ficus thonningii and Leptadenia lancifolis at a range of 13.85-16.65%. The values reported by Okoli et al.15, however, seem to suggested that some Ficus species native to southeastern Nigeria may yield much higher CP in their leaf meals. Ahamefule et al.40 specifically reported a higher CP content of heavily browsed species plants of southeastern Nigeria used in ruminant feeding (14.70-20.65% with a mean value of 17.92%), moderately browsed plants (13.66-24.85% with a mean value of 18.35%) and occasionally browsed plants (13.65-25.55% with a mean value of 18.62±4.34), indicating higher values than the result of the present study. This high variability in the nutrient content of browse plants often encountered in research have been attributed to within species variability, plant part, season, harvesting regimen, location, soil type and age39-42.
Okoli et al.16 reported EE value of 7.00% for R. heudelotii, while for Ficus spp. indigenous to southeastern Nigeria a much lower value of 0.95% was reported by Okoli et al.15. The result was lower than the mean EE content of 5.07% for selected browses of southeastern Nigeria as reported by Okoli et al.16. The value is much lower than the 6.32 and 3.77% reported in G. latifolium and G. kola leaf meals but higher than the 1.35% reported in M. pruriens leaf meals obtained from southeastern Nigeria. The EE contents of the study plant agree with that of Njidda39 who reported a range of 2.00-5.00% for EE of northeastern Nigeria browse forages. It is also similar to the reported EE content of 2.30-5.80% as given by Mecha and Adegbola43 and 2.80% for Panicum maximum reported by Arigbede et al.44.
The CF content of 24.42-26.30% reported for the study plant is in agreement with the 25.25% CF reported by Okoli et al.16 for Ficus spp. of southeastern Nigeria and the 26.93% reported by Kubkomawa6 for the most preferred browses during the dry season in Adamawa state. The values obtained were however higher than the mean CF content of 11.6% reported for selected browses of southeastern Nigeria by Okoli et al.16 but similar to the mean value of 27.72% reported by Udedibie14 in selected plants from the zone. The values are lower than the 18.30% mean CF content reported for browses of west Africa by Le-Houerou37. The observed variations in the crude fibre content of the browses could be attributed to the season of harvest, stage of maturity, type of browse plants, climatic conditions of the area and inherent genetic characteristics of each plant45,46.
Okoli et al.15 reported a much lower 5.20% total ash (TA) content for Ficus spp. of southeastern Nigeria, while a TA content value of 9.80% was reported for R. heudelotii a browse plant closely associated with F. microcarpa in the small ruminant feeding practice at the study area. The values obtained from the present study were high when compared with the mean values of 10.90% reported for West African browse plants or the 7.19 and 8.51% for Southeastern Nigeria browses16,36,43. The values are similar to the 12.21% reported by Udedibie14 in G. latifolium but much higher than the 6.56 and 5.33% reported in M. pruriens and G. kola leaf meals. Ash values are affected by stage of growth. Le Houerou37, Mecha and Adegbola43 and Gohl47 stated that the different figures obtained in the ash content of browse plants in many regions may be due to differences in soil, species and season. The lower range of the NFE obtained in this study is similar to the 30.82% reported by Okoli et al.15 for Ficus spp. of southeastern Nigeria but lower even at its upper range than the 46.27% reported for R. heudelotii in the same study area16. Udedibie14 also obtained similar results (36.53%) as the mean value for the three plants analyzed in southeastern Nigeria. The study plant can serve as a good source of energy material for ruminant animals due to its high energy value. The mean ME value of the study plant at 2238.41 Kcal kg–1 was quite high for a leaf meal and compares favorably with the value obtained for grains by-products48. The values are however slightly similar to the 2937.50, 2275.70 and 2525.02 Kcal kg–1 recorded for G. latifolium, M. pruriens and G. kola respectively by Udedibie14.
The present NDF values reported for the study plant are moderate when compared with low quality roughages which ruminants can effectively degrade46. The present result is similar to the mean 51.54% NDF reported by Okoli et al.16 in selected browses of southeastern Nigeria, with R. heudelotii recording 49.91%. The value is also lower than the 58.86% reported for Mucuna pruriens but higher than the 43.13 and 44.42% reported for G. latifolium and G. kola, respectively14. The result is, however, slightly higher than the upper limit of the findings of Njidda39 who reported 37.3-51.2% NDF for browse forages in northeastern Nigeria. The moderate NDF contents of the analyzed material may be a reflection of the level of maturity of the plant leaves which has provided an opportunity for fibre accumulation in the plant tissues. The voluntary DM intake and digestibility are dependent on the cell wall constituents (fibre), especially the NDF and lignin49. The NDF is the total cell wall which comprises the ADF fraction and hemicellulose. The NDF fraction, therefore, reflects the amount of forage the animal can consume and increases as DM intake decreases. The level of NDF in the animal ration also influences the time of rumination, although the concentration of NDF in feeds is negatively correlated with energy concentration50.
The overall mean ADF of 40.84% obtained in present study compares favourably with the 38.50% ADF value obtained by Okoli et al.16 in selected browses of southeastern Nigeria and the values earlier reports by Oduguwa et al.51, Oji and Isilebo52 and Udedibie14. It is also similar to the findings of Njidda39 who reported ADF contents of 41.2% in some browse forages of northeastern Nigeria. The findings, however, did not corroborate the mean value of 23.30% ADF recorded in 30 browse species analyzed by Gidado et al.53. The ADF value refers to the cell wall portions of the forage made up of cellulose and lignin. The ADF values relate to the ability of an animal to digest the forage. Therefore, as ADF increases the digestibility of the forage decreases54. Lignin is the prime factor influencing the digestibility of plant cell wall material. As it increases, the digestibility intake and animal performance usually decrease. The mean 14.41% recorded in this study was similar to the 13.88% reported by Udedibie14 and particularly lower than the 18.22% reported for G. kola leaf meal.
The mean cellulose value recorded in this study is similar to the 29.34% reported for M. pruriens but higher than the 20.50 and 19.90% reported for G. latifolium and G. kola leaf meals, respectively14. Again, the mean hemicellulose value obtained in the present study is similar to the mean 11.66% reported by Udedibie14 for some leaf meals from southeastern Nigeria and specifically higher than the 6.30% reported for G. kola leaf meal. This result is also higher than the reported values of 4.9-12.7% hemicellulose for browse forages in northeastern Nigeria by Njidda39 indicated that FMLM contains a more digestible fraction. The amount of hemicellulose recorded in the study plant showed that it will have a high level of digestible carbohydrate. The present result is however similar to the mean hemicellulose value of 13.04% reported by Okoli et al.16 for selected browses of Southeastern Nigeria but much lower than the 29.26 and 25 23% reported for Diodia scandens and M. puberula, respectively by the same authors. Aderemi et al.55 also reported such higher hemicellulose values (30.3 and 21.60%) in wheat offals and cassava root chaff respectively.
The FMLMs were rich in all the macro minerals but extremely rich in potassium with the order of mineral concentration being K>Ca>Mg>P>Na, similar to the order published by Udedibie14 for the G. latifolium but different P>Mg in M. pruriens. Udedibie14 also reported much different macro-mineral order (Ca>K>Mg>P>Na) for G. kola leaf meal indicating that probably, K and Ca are the highest macro minerals and Na the least in southeastern Nigeria plants. Okoli et al.15 had earlier shown that generally, browses from southeastern Nigeria are rich in phosphorus and calcium, with Ficus spp. from the region recording mean 1.19% calcium and 2.50% phosphorus indicating that there is no need to supplement these minerals in the rations of ruminants reared at the study area. These findings, therefore show that the plant has the capacity to yield high macro mineral portions and that this could be linked to the soil types at the study location, which has been reported to range from 4.97-5.57 pH15,52. The study plant was therefore rich in iron and zinc and there were no traces of Co and Pb in the plant samples. The order of micro mineral concentration in the leaf meal of the plant is therefore Fe>Mn>Cr>Zn>Cu>Ni, which was similar to the trend published by Udedibie14 for G. latifolium but much different from the micro mineral order of Fe>Zn>Cr>Cu>Mn>Ni and Fe>Mn>Cu>Zn>Cr reported in M. pruriens and G. kola leaf meals, respectively14. It is therefore probable that iron is the highest micro mineral and Ni the least in most southeastern Nigeria plants with Co and Pb being absent in most cases. These results indicate that FMLM is rich in trace minerals and the assayed Fe and Cu levels could support rich hematological profits in animals consuming the plant leaves.
The observed mean ratio values of 2.223 and 0.0625 reported for calcium/phosphorus and sodium/potassium ratios respectively indicate that for every single unit of phosphorus in the plant there are 2.2 units of calcium. These high calcium levels may be reflecting variation in the calcium contents at different locations in the study area. These findings are however at variance with Ca/P ratio of 0.49 in which for every unit of P there were only 0.49 units of calcium in the most cherished browses of Southeastern Nigeria as reported by Okoli et al.15 or the same trend of 0.49 obtained in Ficus spp. by the same workers at Anambra state. Udedibie14 also reported Ca/P ratios of 0.49, 2.97 and 6.06 in G. latifolium, M. pruriens and G. kola, respectively with a mean value of 3.17 for the three plants, a figure much higher than the 2.35 recorded for F. microcarpa. These findings seem to indicate that southeastern Nigerian plants may have varied Ca/P ratios. The Na/K ratios obtained in this study were much lower than the 0.66 obtained by Okoli et al.15 on the mean for most cherished browses of southeastern Nigeria or the 0.72 obtained by the same workers in Ficus spp. of the same study location. The values recorded in F. microcarpa are also much lower than the 0.58, 0.47 and 0.11 ratios reported by Udedibie14 in G. latifolium, M. pruriens and G. kola leaf meals.
CONCLUSION
From this study, it is concluded that leaf meals derived from Ficus microcarpa are relatively rich in crude protein, nitrogen free extract, metabolizable energy, digestible fibers and essential minerals. Animal feeding trials incorporating Ficus microcarpa are recommended in order to evaluate the performance of animals fed with the browse plant.
SIGNIFICANCE STATEMENT
This nutritional study showed that F. microcarpa leaf meal is a good source of essential nutrients that could be included in animal feed to improve productivity. This study has formed the baseline for future research on the nutritional compositions of some common browse plants utilized in animal production in the tropical climate.
ACKNOWLEDGMENT
The authors wish to acknowledge the staff of the Laboratory of the School of Agriculture and Agricultural Technology, Federal University of Technology Owerri, Nigeria for granting us access to their equipments.