Livestock farmers in the warm, humid tropical rainforest agroecological zone of southeastern Nigeria have access to a rich diversity of plant resources in the form of trees, shrubs, herbs, woody vines, weeds, grasses, and forbs for feeding small ruminants. These plants represent an abundant evergreen feed resource in the compound bushes, farmlands, and forests and have continued to supply the nutrient needs of livestock and wildlife in the zone (Achonwa et al., 2017). The diversity, livestock feeding, food, medicinal, and other uses of these plants are well known to the indigenous ruminant farmers in the zone (Okoli et al., 2002 and 2003a; Obua, 2013; Achonwa et al., 2017). Okoli et al. (2003a) reported that more than 163 forage plants are utilized by farmers for small ruminant feeding in the diversity of the forage plants in Anambra, Abia. and Imo states of the zone. Obua (2013) specifically listed 177 forage plants used in the feeding of goats at the mostly agrarian Ohaji/Egbema/Oguta area of Imo state. Significant variations in forage plants preferred by farmers for feeding livestock have also been reported at different sites in the zone, and have been attributed to the effects of the different animal husbandry systems and environmental changes on forage usage and availability in the zone (Njoku, 2006; Okoli et al., 2014a). For example, at many sites in the zone, small ruminants are permanently confined and the fodder is cut and carried to them, while at other sites, they are allowed to roam extensively in search of feed or tethered during the day in the fallow or compound bushes (Gefu et al., 1994).
The southeastern zone was known to harbor a sizable percentage of the rainforest and biological diversity of southern Nigeria, which was exploited for its forest resources, arable farming, small-scale livestock keeping, and several other ecosystem services by the inhabitants (Ndaeyo et al., 2001; Ogbuewu et al., 2016; Chiaka et al., 2022). The fragile ecosystem of the zone has been degraded overtime by persistent anthropogenic pressure and climatic change events, resulting in depletion of the forest resources (Njoku, 2006 and 2009) and alterations in the livelihood activities of the inhabitants. The ruminant forage resource diversity and use habits of the smallholder farmers in the zone are also being altered by the increasing population density and land pressure (Gefu et al., 1994; Madu, 2005). Again, labor requirements and the frequent resource conflicts between livestock owners and crop farmers in recent times have made the livestock confinement option more favorable at most locations in Imo state (Okoli et al., 2014a; Anyanwu et al., 2020).
Under natural conditions, small ruminants spend more than 90% of their feeding time browsing a wide variety of forage plants to achieve about 50% of their total dry matter (DM) intake (Gefu et al., 1994). Age-long indigenous ruminant feeding practices such as the cafeteria method, which involves offering a cocktail of forage plants to the animals at the same time by local farmers in the zone, mimic this feeding habit of small ruminants (Boga et al., 2009). This feeding approach has been used by the ruminant farmers to achieve efficient forage and nutrient supply to the animals, while helping to complement and ameliorate the endogenous toxic effects of specific forages, thereby preventing the emergence of any adverse pathology (Etuk et al., 2005). Similar indigenous knowledge practices with positive outcomes on animal performance were also reported by Thorne et al. (1997) among smallholder ruminant farmers in rural Nepal. The impact of environmental change on forage diversity and availability in Imo state may, however, affect the choice of forage supplied by farmers to their animals and, therefore, their nutrient needs and heal outcomes. Diminishing vegetal resources may lead to changes in forage preferences by the farmers and may also result in fewer plant varieties being included in the cocktail of fodder supplied to the animals. These impacts may vary at different sites in the state, especially between the rural and urban environments, in response to the variation in anthropogenic changes at these sites. This is exemplified by the report of Usman and Nichol (2022) that between 1980 and 2014, there was greater loss in forage resources at locations surrounding urban centers than in rural areas of the northern Savannah zone of the country. It is, therefore, possible that since 20 and 10 years ago when Okoli et al. (2003a) and Obua (2013), respectively, published their studies on the diversity of forage plants in southeastern Nigeria, significant changes may have occurred in the forage dynamics in Imo state to influence their availability and nutrient supply to small ruminants.
This paper presents the results of a study carried out at rural and peri-urban sites in Imo state, southeastern Nigeria, to determine the diversity and the nutrient compositions of the most preferred forage plants used for small ruminant feeding.
This study was carried out at rural sites in Aboh-Mbaise Local Government Area (LGA), located in the southwestern part of Imo state and peri-urban sites in Mbaitoli LGA in the central part of the state in the southeastern agroecological zone of Nigeria. The state is located between latitude 6° and 8°N of the equator and longitude 5.83° and 6°E of the Greenwich Meridian. It has a land area of about 5135 km2, a population of about 5.4 million persons, and population density of 1063 persons per km2 (NPC, 2006 Projections, 2022). Aboh-Mbaise LGA hosts an estimated population of 270,700 persons, while Mbaitoli LGA has an estimated population of 330,100 persons and is the most populated LGA in the state. The climate is marked by a rainy season period, which extends from April to October, and a dry season, extending from November to March. Most of the mean rainfall reaches about 2152 mm per year and is associated with the maritime southwesterly trade winds from the Atlantic Ocean. The average relative humidity is about 80% and could reach up to 90% during the rainy season. The mean daily maximum air temperature ranges from 28°C to 35°C, while the mean daily minimum air temperature ranges from 19°C to 24°C.
The vegetation is typically rainforest (Agboola, 1979) and is characterized by many varieties of densely populated grasses, legumes, shrubs, herbages, and trees, which are not only nutritional, but also exploited for other economic and health purposes (Obua, 2013). The climate favors the production of roots, tubers, cereals, vegetables, nuts, and several cash crops, which are grown mostly by smallholder farmers in small plots of land. Most households rear animals such as sheep, goat, pigs, and poultry mostly on part-time basis (Okoli et al., 2004). Many rural families in southeastern Nigeria keep small ruminants as sources of income, animal manure, readily accessible meat, and for various cultural activities (Achonwa, 2017). Small ruminant farmers at the study sites practice permanent confinement of their animals, while forages are supplemented with kitchen wastes.
The study was undertaken between May and June 2021. The rural area survey was carried out at Aboh Mbaise LGA, while the peri-urban survey was carried out at Mbaitoli LGA. Both LGAs and communities were selected based on the results of an informal survey of the study area, during which the researchers made themselves known to the community leaders and with their help, they identified the small ruminant farmers and explained the nature of the study to them (Achonwa, 2017). The ruminant farmers were selected based on their willingness to participate in the study, having at least four small ruminants in their compounds, and having at least 5 years of experience in ruminant keeping. Ten ruminant farmers who met the selection criteria were selected purposively from each LGA across the study communities. Gender balance of respondents was ensured to generate representative data since according to Okoli et al. (2003a), information on diversity of forage plants varies across gender and study sites in the study area. The study was carried out by the same researchers to ensure data consistency.
Each farmer was visited once for the purposes of plant selection and identification. The researchers accompanied each farmer to the surrounding compound bushes and fallow lands for direct sampling, identification, and documentation of the fodder plants using their English and Igbo language names. Representative samples of the identified plants were collected, tagged, and stored for botanical identification. The farmers were also asked to identify the plants that served as food at the study sites. The information gathered at the sites in each LGA was pooled and used to build the list of forage plants fed to small ruminants in the LGA. All the plant samples were identified botanically at the Department of Crop Science and Technology, Federal University of Technology Owerri, Nigeria. Two of the sampled plants could not be readily identified and were preserved for future identification, while their Igbo names were adopted for the study. The listed fodder plants were ranked using their frequency of mention by the farmers. The seven most commonly occurring plants at each LGA were thereafter selected and analyzed for their nutrient values.
The apical leaves of the most commonly occurring forage plants were gathered and sun dried until they became crispy to touch. They were packed in polyethylene pouches, labeled, and sent to the laboratory for their proximate and mineral analysis using the methods described by Association of Official Analytical Chemists (AOAC) International (2016). The proximate analysis was carried out to determine the DM, crude protein (CP), ether extract (EE), crude fiber (CF), total ash (TA), and nitrogen-free extract (NFE) values. The mineral concentrations in the plants were also analyzed with an atomic absorption spectrophotometer (Model 210 VGB, Bulk Scientific) to determine the calcium (Ca), phosphorus (P), sodium (Na), potassium (K), magnesium (Mg), manganese (Mn) iron (Fe), zinc (Zn), copper (Cu), and lead (Pb) content. Using the data generated, the mutual proportions of the individual minerals were calculated as ratios of Ca:P, K:Mg, Na:K, Ca:Mg K(Ca + Mg), and (K + Na):(Ca + Mg) (Jakubus and Graczyk, 2022). The unit milliequivalents per kg was used to calculate K(Ca + Mg) and (K + Na):(Ca + Mg) according to Oetzel (1993), while mg/100 g was used to calculate the other values.
The fodder diversity, proximate composition, and mineral concentration data were analyzed using descriptive statistics such as frequency counts, percentages, means, and standard deviation (SPSS, 2012). To predict the relative nutrient supply to the small ruminants at each study location, the proximate and mineral values of the seven most commonly identified fodder plants were adopted as the realistic representation of the daily fodder-derived nutrients supplied to the animals. This is based on the fact that the choice or cafeteria method of feeding which involves the offering of a cocktail of several forage plants at the same time is traditionally used by farmers to supply nutrients to permanently confined small ruminants at the study area (Gefu et al., 1994). Thus, the most commonly identified fodder plants were regarded as the daily cocktail of forage offered to the animals at the study sites. The overall mean proximate and mineral values of the forage plants at each study site were, therefore, compared using the Student’s t-test method (SPSS, 2012) to determine the statistical differences in nutrient supply at the sites.
The results presented in Table 1 show that 21 and 15 fodder plants were identified at the rural and peri-urban sites, respectively, indicating a higher diversity of fodder plants at the rural site. Overall, 23 fodder plants were identified, indicating some level of homogeneity in farmers’ forage knowledge at the two sites. The palm frond (Eleasia guineensis) was identified by all farmers at both the study sites, while the African Rosewood (Pterocarpus santalinoides) and Indian bamboo (Bambusa tulda) were also identified by all farmers at the peri-urban site. Two grass species (Pennisetum purpureum and Achara field) were included in the rural list, while none was included in the peri-urban list. The frequency of occurrence of the different fodder plants has been derived from the list in Table 1, and is presented in Table 2 and shows that most of the fodder plants at the rural site were identified once (38.89%) and twice (22.22%). At the peri-urban site, 26.67% of the plants were identified by four farmers and 20.0% each were identified by five and 10 farmers, while 6.67% each of the plants was identified by one and two farmers. The results also show that while 61.11% of the forage plants at the rural site were identified 1–2 times, the value for the peri-urban sites was only 13.34%. Inversely, 33.33% of the plants at the peri-urban site were identified 9–10 times, while only 5.56% at the rural site were similarly identified. These findings highlight major differences in fodder plant usage among the farmers at the two sites and may be attributed to loss of diversity and lesser fodder options at the peri-urban site than the rural site.
Diversity of forage plants used in feeding small ruminants by farmers at the rural and peri-urban sites in Imo state
Tabelle 1. Vielfalt der Futterpflanzen, die von Landwirten in ländlichen und stadtnahen Gebieten im Bundesstaat Imo zur Fütterung kleiner Wiederkäuer verwendet werden
1 | African Rosewood | Oha | 1 (10.00) | 2 (20.00) | 3 (15.00) | |
2 | African velvet tamarind | Icheku/Nchichi | 8 (80.00) | 5 (50.00) | 13 (65.00) | |
3 | Avocado | Ube Bekee | 5 (50.00) | 9 (90.00) | 14 (70.00) | |
4 | Bitter leaf | Onugbu | 3 (30.00) | 1 (10.00) | 4 (20.00) | |
5 | Wild cane | Okpete | 3 (30.00) | - | 3 (15.00) | |
6 | Caesar weed | Udo | 2 (20.00) | - | 2 (10.00) | |
7 | Cassava | Akpu | 2 (20.00) | 4 (40.00) | 6 (30.00) | |
8 | Elephant grass | Achara nwakita | 3 (30.00) | 3 (15.00) | ||
9 | Gmelina | Melina | 1 (10.00) | - | 1 (5.00) | |
10 | Guava | Gova | 1 (10.00) | 5 (50.00) | 6 (30.00) | |
11 | Seam weed (Eliza) | Awolowo | 2 (20.00) | - | 2 (10.00) | |
12 | African rosewood | Oha Nturukpa | 1 (10.00) | 10 (100.00) | 11 (55.00) | |
13 | Palm fronds | Igu Nkwu | 10 (100.00) | 10 (100.00) | 20 (100.00) | |
14 | African pear | Ube | 2 (20.00) | - | 2 (10.00) | |
15 | Banana/plantain | Abirica/Une | 1 (10.00) | 9 (90.00) | 10 (50.00) | |
16 | Hemorrhage plant | Oranjila | 4 (40.00) | 6 (60.00) | 10 (50.00) | |
17 | Indian bamboo | Ekwe achara | - | 10(100.00) | 10 (50.00) | |
18 | Breadfruit | Ukwa | - | 5 (50.00) | 5 (25.00) | |
19 | Kola | Oji | - | 4 (40.00) | 4 (20.00) | |
20 | Atumkpiri | - | 4 (40.00) | 4 (20.00) | ||
21 | African plum | Njikara | - | 2 (20.00) | 2 (10.00) | |
22 | Mpupu | 1 (10.00) | - | 1 (5.00) | ||
23 | Achara field | 1 (10.00) | - | 1 (5.00) | ||
Total | 18 | 15 | 23 |
The frequency of occurrence of forage plants used in feeding small ruminants at the rural and peri-urban sites
Tabelle 2. Häufigkeit des Vorkommens von Futterpflanzen, die zur Fütterung kleiner Wiederkäuer in ländlichen und stadtnahen Gebieten verwendet werden
1 | 7 (38.89) | 1 (6.67) | 8 (24.24) |
2 | 4 (22.22) | 1 (6.67) | 5 (15.15) |
3 | 3 (16.67) | - | 3 (9.09) |
4 | 1 (5.56) | 4 (26.67) | 5 (15.15) |
5 | 1 (5.56) | 3 (20.00) | 4 (12.12) |
6 | - | 1 (6.67) | 1 (3.03) |
7 | - | - | - |
8 | 1 (5.56) | - | 1 (3.03) |
9 | - | 2 (13.33) | 2 (6.06) |
10 | 1 (5.56) | 3 (20.00) | 4 (12.12) |
The number of fodder plants identified by the farmers in this study is much smaller than the more than 163 identified at three southeastern states (Anambra, Abia, and Imo states) of Nigeria and the 177 identified by Obua (2013) at Ohaji/Egbema/Oguta area of Imo state. This is probably due to the differences in the number of respondents sampled in the different studies and, more importantly, the possible erosion of forage diversity over time in the study area. Ekwe et al. (2020) also documented 26 forage species made up of 13 grasses, five legumes, two trees, and six shrubs in their more recent study of forages available to grazing goats at Abakiliki area of southeastern Nigeria. Anyanwu et al. (2020) have reported significant shifts from small ruminant farming (4.8%) to poultry farming (33.7%) and cultured fish farming (25.3%) among farming households in three LGAs of Imo state, although about 74.0% of these households had a history of small ruminant keeping. It is, therefore, probable that such significant decline in small ruminant keeping in the state will be accompanied by serious erosion of knowledge about fodder diversity. The differences observed between the fodder dynamics at the rural and peri-urban sites also support the recent report by Usman and Nichol (2022) that there is greater loss in forage resources at locations surrounding urban centers than in rural areas of the northern Savannah zone of Nigeria. These variations are arguably driven by anthropogenic and socioeconomic changes which may have varied impacts on forage resources and the options available to the smallholder farmers at the different sites.
The results presented in Table 3 show that 14 of the fodder plants used to feed small ruminants, which were identified by the farmers were also food-bearing plants – 10 (55.56%) at the rural site and 12 (80.00%) at the peri-urban site and 66.67% overall – thus highlighting again the variations in fodder use approach at the two sites. The overall value is much higher than the 22.06% reported by Okoli et al. (2003a) in their much wider study covering three states in southeastern Nigeria. The scenario at the peri-urban site is interesting and shows the possible human response to the diminishing compound bushes and fallows that traditionally harbor these forage plants. The results seem to support the report by Okoli et al. (2014b) that most rural farmers tend to selectively allow plants that have more than one value in their compound bushes. Furthermore, it is probable that as farm/forage lands shrink at the peri-urban site, the shared dependence of both the farmers and their animals on the available biological diversity for sustenance increasingly demands the conservation of plants that have multiple values (Obua, 2013). Indeed, Okoli et al. (2014b) postulated that the future of successful livestock feeding in southeastern Nigeria will partly depend on the identification and domestication of selected highly nutritious forage plants that have other values such as food, medicinal, fuel, shading, soil enrichment, and ornamental values.
Distribution of food-bearing plants used as forage for small ruminants by farmers at the rural and peri-urban sites in Imo state
Tabelle 3. Verteilung der Futterpflanzen, die von Landwirten in ländlichen und stadtnahen Gebieten im Bundesstaat Imo als Futter für kleine Wiederkäuer verwendet werden.
1 | Leaves | 1 (10.00) | - | 1 (4.55) | |
2 | Seeds | 8 (80.00) | 5 (41.67) | 13 (59.09) | |
3 | Fruits | 5 (50.00) | 9 (75.00) | 14 (63.64) | |
4 | Leaves | 3 (30.00) | 1 (8.33) | 4 (18.18) | |
5 | Tuber | 2 (20.00) | 4 (33.33) | (27.27) | |
6 | Fruits | 1 (10.00) | 5 (41.67) | 6 (27.27) | |
7 | Leave | 1 (10.00) | 10 (83.33) | 11 (50.00) | |
8 | Oil nuts | 10 (100.00) | 10 (83.33) | 20 (90.90) | |
9 | Fruits | 2 (20.00) | - | 2 (9.09) | |
10 | Fruits | 1 (10.00) | 9 (75.00) | 10 45.45) | |
11 | Seeds | - | 5 (41.67) | 5 (22.73) | |
12 | Nuts | - | 4(33.33) | 4 (18.18) | |
13 | Plum | - | 2 (16.67) | 2 (9.09) | |
14 | Leaves | - | 4 (33.33) | 4 (18.18) | |
Number and percentages of food bearing plants | 10 (55.56) | 12 (80.00) | 22 (66.67) |
The lists of seven most commonly identified forage plants for feeding small ruminants at the rural and peri-urban sites are shown in Table 4. Again, six out of the seven plants listed at the peri-urban site (E. guineensis, P. santalinoides, Musa acuminata/paradisiaca, Persea americana, B. tulda, and Aspilia africana) were identified by 8–10 farmers, with the range being 5–10 farmers per plant. At the rural site, however, only two plants (E. guineensis and Dialium guineense) were identified by 8–10 farmers, with the range being 3–10, indicating that fodder use knowledge is more closely shared among the farmers at the peri-urban site than the rural site. Overall, four of the plants (E. guineensis, P. americana, D. guineense, and A. africana) were commonly identified at both sites. These findings support the observations by Okoli et al. (2003a) that changes in the abundance of forage resources may also lead to changes in forage preferences by farmers and may result in fewer plant varieties being included in the cocktail of fodder supplied to the ruminants in southeastern Nigeria.
List of the seven most commonly identified forage plants for feeding small ruminants at rural and peri-urban sites in Imo state
Tabelle 4. Liste der sieben am häufigsten identifizierten Futterpflanzen für die Fütterung kleiner Wiederkäuer an ländlichen und stadtnahen Stand-orten im Bundesstaat Imo
1 | 10 | 10 | |
2 | - | 10 | |
3 | - | 9 | |
4 | 5 | 9 | |
5 | - | 9 | |
6 | 8 | 5 | |
7 | 4 | 8 | |
8 | 3 | - | |
9 | 3 | - | |
10 | 3 | - | |
Total | 7 | 7 |
The proximate compositions of the commonly identified fodder plants at the rural and peri-urban sites are presented in Table 5. The common fodders at the peri-urban site recorded higher mean DM (87.80 ± 0.99 g/100 g) than those at the rural site (86.97 ± 1.30 g/100 g). The CP values ranged from 5.96% to 15.17% (mean 10.09% ± 3.17%) at the rural site and from 5.97% to 14.06% (mean 9.83 ± 2.42 g/100 g) at the peri-urban site, indicating slightly higher value at the rural site. CP values recorded for
Proximate compositions (g/100 g) of the mostly commonly identified forage plants at the study sites
Tabelle 5. Näherungszusammensetzung (g/100 g) der am häufigsten identifizierten Futterpflanzen an den Untersuchungsstandorten
Forage plant | DM | CP | EE | CF | TA | NFE |
---|---|---|---|---|---|---|
85.29 | 5.96 | 2.18 | 19.84 | 11.64 | 45.67 | |
89.35 | 9.04 | 1.85 | 8.66 | 9.42 | 60.02 | |
86.78 | 8.74 | 2.01 | 20.74 | 10.16 | 45.13 | |
87.24 | 13.63 | 5.73 | 10.74 | 14.37 | 47.77 | |
87.47 | 15.17 | 4.96 | 6.94 | 10.35 | 50.05 | |
85.81 | 9.11 | 1.98 | 22.28 | 9.21 | 43.23 | |
86.85 | 9.00 | 1.66 | 13.53 | 9.05 | 53.57 | |
Minimum | 85.81 | 5.96 | 1.66 | 6.94 | 9.05 | 43.23 |
Maximum | 89.35 | 15.17 | 5.73 | 22.28 | 14.37 | 60.02 |
Mean | 86.97 | 10.09 | 2.91 | 14.67 | 10.60 | 49.35 |
SD | 1.30 | 3.17 | 1.68 | 6.25 | 1.88 | 5.82 |
88.64 | 14.06 | 6.11 | 9.95 | 8.56 | 49.96 | |
86.35 | 9.12 | 2.25 | 19.71 | 9.61 | 45.66 | |
87.94 | 9.09 | 1.47 | 26.15 | 11.87 | 38.85 | |
88.46 | 10.14 | 2.04 | 10.16 | 10.34 | 55.78 | |
87.35 | 5.97 | 0.96 | 22.65 | 5.15 | 52.62 | |
86.86 | 10.86 | 3.85 | 10.15 | 8.33 | 53.67 | |
89.04 | 9.61 | 2.18 | 17.69 | 10.02 | 49.54 | |
Minimum | 86.35 | 5.97 | 0.96 | 9.95 | 5.15 | 38.85 |
Maximum | 89.04 | 14.06 | 6.11 | 26.15 | 11.87 | 55.78 |
Mean | 87.80 | 9.83 | 2.69 | 16.64 | 9.12 | 49.44 |
SD | 0.99 | 2.42 | 1.75 | 6.65 | 2.11 | 7.70 |
DM = dry matter, CP = crude protein, EE = ether extract, CF = crude fiber, TA = total ash, NFE = nitrogen-free extract, SD = standard deviation.
The mineral concentrations (mg/kg) in the most commonly identified forage plants at the study sites are shown in Table 6. Generally, the macromineral concentrations in the forage plants are low in comparison to the range of values recommended for goats (Mcdowell, 1985; Kessler, 1991; NRC 2007) and vary across study sites and within plant species. Mean concentrations of Ca, P, Na, K, and Mg at the rural and peri-urban sites were 195.3 ± 93.2 and 350.9 ± 351.8 mg/kg, 307.8 ± 363.8 and 524.3 ± 356.7 mg/kg, 363.9 ± 240.7 and 315.8 ± 156.9 mg/kg, 170.7 ± 61.6 and 128.0 ± 40.7 mg/kg, and 53.3 ± 56.3 and 39.2 ± 17.5 mg/kg, respectively. The mean mineral concentrations of Ca and P were higher at the peri-urban site, while the concentrations of Na, K, and Mg were higher at the rural site. The highest concentrations of Ca, P, and Na at the rural site were recorded in the
Mineral concentrations (mg/kg) in the most commonly identified forage plants at the study sites
Tabelle 6. Mineralstoffkonzentrationen (mg/kg) in den am häufigsten identifizierten Futterpflanzen an den Untersuchungsstandorten
Forage plant | Ca | P | Na | K | Mg | Mn | Fe | Zn | Cu | Pb |
---|---|---|---|---|---|---|---|---|---|---|
211.64 | 74.68 | 406.75 | 128.16 | 23.58 | 6.85 | 10.64 | 2.84 | 3.54 | 0.00 | |
116.86 | 133.74 | 375.37 | 192.66 | 24.37 | 14.18 | 21.52 | 3.58 | 1.09 | 0.03 | |
341.72 | 1108.57 | 724.17 | 173.59 | 62.18 | 27.22 | 21.21 | 3.60 | 1.07 | 0.51 | |
165.65 | 79.55 | 615.98 | 151.56 | 11.87 | 19.64 | 12.60 | 2.71 | 1.56 | 0.08 | |
116.18 | 317.62 | 194.51 | 291.35 | 18.25 | 17.85 | 38.81 | 1.94 | 0.41 | 0.00 | |
299.76 | 168.94 | 121.85 | 161.64 | 60.88 | 25.91 | 7.69 | 2.74 | 2.96 | 0.01 | |
115.87 | 271.92 | 108.72 | 96.37 | 172.63 | 22.11 | 9.53 | 3.16 | 0.76 | 0.01 | |
Minimum | 115.87 | 74.68 | 108.72 | 96.37 | 11.87 | 6.85 | 7.69 | 1.94 | 0.41 | 0.00 |
Maximum | 341.72 | 1108.57 | 724.17 | 291.35 | 172.63 | 27.22 | 38.81 | 3.60 | 3.54 | 0.51 |
Mean | 195.38 | 307.86 | 363.91 | 170.76 | 53.38 | 19.11 | 17.43 | 2.94 | 1.63 | 0.09 |
SD | 93.29 | 363.84 | 240.73 | 61.68 | 56.33 | 7.04 | 10.91 | 0.58 | 1.17 | 0.19 |
202.76 | 118.72 | 486.85 | 106.86 | 10.87 | 15.26 | 17.47 | 3.16 | 1.85 | 0.09 | |
418.61 | 928.46 | 500.84 | 137.93 | 55.76 | 19.53 | 23.44 | 3.54 | 1.07 | 0.51 | |
328.76 | 1108.14 | 111.76 | 95.85 | 31.33 | 22.32 | 10.06 | 3.17 | 1.89 | 1.06 | |
99.67 | 412.65 | 295.16 | 179.64 | 33.10 | 19.40 | 20.17 | 4.52 | 2.03 | 0.01 | |
1105.11 | 416.86 | 310.74 | 121.20 | 61.46 | 26.20 | 31.53 | 3.15 | 1.83 | 0.17 | |
194.22 | 292.81 | 121.76 | 74.19 | 50.31 | 12.66 | 23.28 | 1.82 | 0.86 | 0.00 | |
107.83 | 392.47 | 383.63 | 180.64 | 31.57 | 16.42 | 21.95 | 4.29 | 2.17 | 0.02 | |
Minimum | 99.67 | 118.72 | 111.76 | 74.19 | 10.87 | 12.66 | 10.06 | 1.82 | 0.86 | 0.00 |
Maximum | 1105.11 | 1108.14 | 500.84 | 180.64 | 61.46 | 26.20 | 31.53 | 4.52 | 2.17 | 1.06 |
Mean | 350.99 | 524.30 | 315.82 | 128.04 | 39.20 | 18.83 | 21.13 | 3.38 | 1.69 | 0.26 |
SD | 351.80 | 356.76 | 156.97 | 40.74 | 17.57 | 4.54 | 6.53 | 0.89 | 0.50 | 0.39 |
SD = standard deviation.
The mean concentrations of microminerals in the forage plants also varied across study sites and within plant species. Mean concentrations of Mn, Fe, Zn, Cu, and Pb at the rural and peri-urban sites were 19.11 ± 7.04 and 18.83 ± 4.54 mg/kg, 17.43 ± 7.04 and 21.13 ± 6.53 mg/kg, 2.94 ± 0.58 and 3.38 ± 0.89 mg/kg, 1.63 ± 1.17 and 1.69 ± 0.50 mg/kg, and 0.09 ± 0.19 and 0.26 ± 0.39 mg/kg, respectively. The mean Fe, Zn, Cu, and Pb contents were higher in the forage samples from the peri-urban site, while the Mn value was higher at the rural site.
The Pb levels were generally low, with the highest values being 1.06 and 0.51 mg/kg in
Some mineral elements may antagonize or synergize each other during their uptake from the soil by forage plants and can therefore influence their values and quantitative ratios in the plant tissue (Rietra et al., 2017). However, limited information exists on the mineral ratios in the forages fed to ruminants in southeastern Nigeria, despite its importance in livestock nutrition and health. Such information is valuable for the establishment of the levels of supplementation needed in animals fed indigenous forage plants (Kumar and Soni, 2014; Reine et al., 2020). The mean ratios at the rural and peri-urban sites were: for Ca:P 1.24 ± 0.99 and 0.90 ± 0.93, for Na:K 2.27 ± 1.52 and 2.70 ± 1.22, for Ca:Mg 6.46 ± 4.13 and 9.28 ± 6.72, for K:Mg, 6.87 ± 5.70 and 2.28 ± 2.95, for K:(Ca + Mg) 0.88 ± 0.67 and 0.59 ± 0.52, and for (K + Na):(Ca + Mg) 2.56 ± 1.48 and 1.93 ± 1.52, respectively (Table 7). The ratios were mostly varied across study sites in response to the variations in the mineral contents of the forages from the sites. The Ca:P, K:Mg, and K:(Ca + Mg) ratios calculated at the rural site were higher than those of the peri-urban sites, while the others were lower. Balanced Ca and P levels in the forage are particularly important to ensure their availability, utilization, and optimal animal health. The Ca:P ratios in
Mean mineral ratios in the preferred forage plants at the sites
Tabelle 7. Mittlere Mineralstoffverhältnisse in den bevorzugten Futterpflanzen an den Standorten
Forage plant | Ca:P | Na:K | Ca:Mg | K:Mg | K:(Ca + Mg) | (K + Na): Ca + Mg) | Zn:Cu | Fe:Cu |
---|---|---|---|---|---|---|---|---|
2.83 | 3.17 | 8.98 | 5.44 | 0.55 | 2.27 | 0.80 | 3.01 | |
0.87 | 1.95 | 4.80 | 7.90 | 1.36 | 4.02 | 3.28 | 19.74 | |
0.31 | 4.17 | 5.50 | 2.79 | 0.43 | 2.22 | 3.37 | 19.82 | |
2.08 | 4.06 | 13.96 | 12.77 | 0.85 | 4.32 | 1.73 | 8.08 | |
0.37 | 0.67 | 6.37 | 15.96 | 2.17 | 3.61 | 4.73 | 94.66 | |
1.77 | 0.75 | 4.92 | 2.66 | 0.45 | 0.79 | 0.93 | 2.59 | |
0.43 | 1.13 | 0.67 | 0.56 | 0.33 | 0.71 | 4.16 | 12.54 | |
Minimum | 0.31 | 0.67 | 0.67 | 0.56 | 0.33 | 0.71 | 0.80 | 2.59 |
Maximum | 2.83 | 4.06 | 13.97 | 12.77 | 2.17 | 4.47 | 4.16 | 94.66 |
Mean | 1.24 | 2.27 | 6.46 | 6.87 | 0.88 | 2.56 | 2.71 | 22.92 |
SD | 0.99 | 1.52 | 4.13 | 5.70 | 0.67 | 1.48 | 1.57 | 34.41 |
1.71 | 4.56 | 18.65 | 9.84 | 0.50 | 2.78 | 1.71 | 9.44 | |
0.45 | 3.63 | 7.51 | 2.47 | 0.29 | 1.35 | 3.31 | 21.91 | |
0.30 | 1.17 | 10.49 | 3.06 | 0.27 | 0.58 | 1.68 | 5.32 | |
0.24 | 1.64 | 3.01 | 5.43 | 1.35 | 3.58 | 2.23 | 9.94 | |
2.65 | 2.56 | 17.98 | 1.97 | 0.10 | 0.37 | 1.72 | 17.23 | |
0.66 | 1.64 | 3.86 | 1.47 | 0.30 | 0.80 | 2.12 | 27.07 | |
0.27 | 2.12 | 3.41 | 5.72 | 1.31 | 4.08 | 1.98 | 10.12 | |
Minimum | 0.30 | 1.17 | 3.01 | 1.47 | 0.10 | 0.37 | 1.68 | 5.32 |
Maximum | 2.65 | 4.56 | 18.65 | 9.84 | 1.35 | 4.08 | 3.31 | 27.07 |
Mean | 0.90 | 2.47 | 9.28 | 2.28 | 0.59 | 1.93 | 2.11 | 14.43 |
SD | 0.93 | 1.22 | 6.72 | 2.95 | 0.52 | 1.52 | 0.57 | 7.85 |
SD = standard deviation.
The forage plants recorded lower K:(Ca + Mg) ratios than the maximum tolerable ratio range of 1.6–2.2:1 recommended by NRC (2000), indicating that symptoms associated with magnesium deficiency, such as grass tetany, will not occur in the ruminants consuming these forage plants (Dele et al., 2021). Again, the (K + Na):(Ca + Mg) ratios recorded in
The mean Zn:Cu and Fe:Cu ratios in the forage plants were 2.71 ± 1.57 and 22.92 ± 34.41, respectively, at the rural site and 2.11 ± 0.57 and 14.43 ± 7.85, respectively, at the peri-urban site. The values ranged from 0.80 to 4.16 and from 2.59 to 94.66 at the rural site and from 1.68 to 3.31 and from 5.32 to 27.07 at the peri-urban site, respectively. High level of Zn in the forage has been shown to antagonize copper absorption, while Zn:Cu ratios greater than 16 have been associated with adverse conditions in both humans and animals (Turnlund, 1988; Ma and Betts, 2000). Hodzic et al. (2013) reported a range of 3.58–7.60 for Zn:Cu ratios in medicinal plants from Bosnia and Herzegovina. Achonwa et al. (2019), reported a Zn:Cu ratio of 1.03 in
Feeding of trees, shrubs, herbs, woody vines, weeds, grasses, and forbs is the traditional method of supplying nutrients to permanently confined small ruminants at several locations in southeastern Nigeria. Under this production system, several forage plants are cut and supplied to the animals as a cocktail, thus creating a choice or cafeteria feeding that gives the animals the chance to make their own diets to match their nutritional requirements (Gefu et al., 1994; Boga et al., 2009). The results presented in Tables 8 and 9 represent comparisons of the relative nutrient supplies to small ruminants at the rural and peri-urban sites. There were no significant differences (
Comparison of the relative nutrient supplies for small ruminants at the rural and peri-urban sites
Tabelle 8. Vergleich der relativen Nährstoffzufuhr für kleine Wiederkäuer an den ländlichen und stadtnahen Standorten
Proximate parameter (%) | Rural site | Peri-urban site | SEM | p < 0.05 |
---|---|---|---|---|
Dry matter | 86.97 | 87.80 | 0.32 | 0.202 |
Crude protein | 10.09 | 9.83 | 0.72 | 0.867 |
Ether extract | 2.91 | 2.69 | 0.44 | 0.818 |
Crude fiber | 14.67 | 16.64 | 1.68 | 0.580 |
Total ash | 10.60 | 9.12 | 0.55 | 0.193 |
Nitrogen-free extract | 49.35 | 49.44 | 1.48 | 0.977 |
SEM=Standard error of difference of mean
Comparison of the relative mineral supplies for small ruminants at the rural and peri-urban sites
Tabelle 9. Vergleich der relativen Mineralstoffversorgung für kleine Wiederkäuer an den ländlichen und stadtnahen Standorten
Minerals (mg/kg) | Rural site | Peri-urban site | SEM | p < 0.05 |
---|---|---|---|---|
Calcium | 195.38 | 350.99 | 69.52 | 0.280 |
Phosphorus | 307.86 | 524.30 | 97.39 | 0.284 |
Sodium | 363.91 | 315.82 | 52.60 | 0.666 |
Potassium | 170.76 | 128.04 | 14.67 | 0.152 |
Magnesium | 53.39 | 39.20 | 10.89 | 0.536 |
Manganese | 19.11 | 18.83 | 1.52 | 0.931 |
Iron | 17.43 | 21.13 | 2.36 | 0.456 |
Zinc | 2.94 | 3.38 | 0.20 | 0.293 |
Copper | 1.63 | 1.67 | 0.23 | 0.928 |
Lead | 0.09 | 0.26 | 0.08 | 0.310 |
Ca:P | 1.24 | 0.90 | 0.25 | 0.521 |
Na:K | 2.27 | 2.47 | 0.36 | 0.788 |
Ca:Mg | 6.46 | 9.27 | 1.48 | 0.364 |
K:Mg | 6.87 | 4.28 | 1.22 | 0.307 |
K:(Ca + Mg) | 0.88 | 0.59 | 0.16 | 0.386 |
(K + Na):Ca + Mg) | 2.56 | 1.93 | 0.40 | 0.448 |
Zn:Cu | 2.71 | 2.11 | 0.31 | 0.354 |
Fe:Cu | 22.92 | 14.43 | 6.17 | 0.514 |
It can be concluded from the results of this study that a higher diversity of fodder plants exists at the rural sites compared to the peri-urban sites. There is greater loss in forage resources at locations surrounding urban centers than in rural areas. This can be attributed to anthropogenic and socioeconomic changes. Majority (80%) of the fodder plants identified by the small ruminant farmers at the peri-urban sites were also food-bearing plants, showing the possible human response to the diminishing compound bushes and fallows that as farm/forage lands shrink at the peri-urban site, the shared dependence of both the farmers and their animals on the available biological diversity for sustenance increases.
Overall, four of the plants (
It was concluded that despite the diversity and differences in forage selection at the two sites, the relative nutrient supplies to small ruminants will likely be similar if the cafeteria system of forage provision practiced at the sites is adhered to. The future of successful livestock feeding in southeastern Nigeria will partly depend on the identification and domestication of selected highly nutritious forage plants that have other values such as food, medicinal, fuel, shading, soil enrichment, and ornamental values.