Effects of Substitution of the Imported Super Concentrate with Graded Levels of Marula (Sclerocarya birrea) Kernel Meal on Growth Performance and Meat Quality of Broiler Chicks

Introduction

Poultry is kept under different production patterns to provide high quality protein sources in Sudan. Evidence has shown that chickens provide rural households with scarce animal protein (meat and eggs) and being a reliable source of petty cash. Moreover, chickens are used for traditional ceremonies and festivals in some cultures. It is asserted that intake of quality animal protein provides good health and strengthens manpower needed to alleviate poverty and ensure food and nutritional security for socio-economic development of rural households [1]. The basic features of this type of production is the lower cost of care and feeding as a secondary activity adopted feeding small herds of chickens on the municipal agricultural waste and food scraps at home. Semi intensive production patterns have emerged in the peri-urban areas to meet the growing demand of eggs and meat. Family poultry production units are also growing at increasing level so rapidly. Governmental and commercial services such as provision of vaccines, drugs and supplements have assisted in introduction of modern systems of poultry production, especially provision of veterinary services, feed manufacturing and extension services in the field of management [2]. Although the continuous development of research in feed industry and poultry production grew enormously Idris AA [3], but it was faced by many constraints, mostly associated with feeding. Perhaps this is the single cost that makes up about 70-75 % of the total production costs. To sustain high levels of production, imported concentrates and mixture of multi vitamins were necessary. Those inputs are obtained at high cost. Some feed ingredients are competed for between poultry and humans. Locally available feed ingredients that are observed being ingested by birds or used for rations formulation are expensive and competed for between poultry and humans and are not always available for small private sector. The challenges that face poultry production necessitate search for alternative feed ingredients to the feed sources that are characterized by high nutritional value, low cost and not competed for between humans and poultry in order to minimize the production cost and maximize profitability. Sclerocarya birrea is a tree species that is adapted to the environment of South Kordofan and produces large amounts of fruits which contain oil and can also give fodder for browsing livestock.

Sclerocarya birrea meal is a widely used feed supplement with high energy content and an amino acid profile close to ideal. The protein quality of SBM is high for poultry, and Sclerocarya birrea meal is a particularly good source of lysine, arginine and tryptophan, but it is deficient in methionine plus cysteine, threonine and valine [4].

Marula (Sclerocarya birrea Caffra), an indigenous fruit bearing tree, whose seed has a high content of ascorbic acid (2960 mg/100 g), calcium (51mg/100g) and phosphorus (19 mg/100 g), While the fruit pulp of Sclerocarya birrea Caffra contains 84% carbohydrate the kernels S. birrea Caffra contains 36.7% crude protein. These favorable nutritional attributes make S. birrea Caffra kernel meal a potential protein and energy source in poultry feed [5]. The main objective of this study is to assist in development of low cost sustainable, poultry production systems based on locally available feed resources to maximizing profit of the poultry industry and to study the effect of _Sclerocarya birre_a meal as substitute for super concentrate in growth performance and meat quality of broiler.

Results and Discussion

The chemical composition of Sclerocarya birrea kernel meal collected from four sites is illustrated in table 1 The results showed that Sclerocarya birrea kernel meal has remarkably high content of CP (12.1 % DM) and NFE (54.5% DM), with moderate content of Ash (4.5 % DM) and low content of EE (1.5 %DM) and CF (21.1%). Mdziniso PM, et al. [10] reported same results for ash (5.43 %DM) and different results for CP (47 % DM) and EE (34.35 % DM), and CF (5.8% g/kg DM). Moreover, Mthiyane MN, et al. [11], reported contradicting results for 47 % CP, 28.8% EE, % Ash and similar CP (470.0–470.21 g/kg DM) and EE (289.6–394 g/kg. Mthiyane MN, et al. [11 ], reported that The CP content of MSC was found to be 47.21% DM. Mthiyane MN, et al. [11], reported lower values of CP for Sclerocarya birrea, they stated that the protein content of Marula seed obtained was 6.17%. This huge difference may be due to the use of the whole nut without removing the oil and kernel thus the protein concentration may have become diluted by the oil and the hard shell of the kernel.

The effects of inclusion of Sclerocarya birrea kernel meal as substitute for super-concentrate as protein source in broiler rations on feed intake is presented in Table 3. It was observed that feed intake increased upon addition of Sclerocarya birrea kernel meal in rations than the conventionally used protein source and super-concentrate though feed intake increased gradually over a period of time for all groups, with the advanced age, but this intake was the highest (9.76 g) in group C and lowest (7.11g) in Group E. The increased feed intake could be attributed to the fact that the meal contained a significant proportion of essential amino acids and fatty acids that enhanced intake and digestibility. The intake was decreased when the marula seed meal inclusion was greater than 5%. The meal contained higher levels of fat and this is consistent with results found by Habani, et al. [12] who reported that broiler feed intake when an ingredient high in lipids replaced another that had low lipid content. In this regard, Mthiyane MN, et al. [13] reported that the adverse effect of high level of Sclerocarya birrea may be due to high level lipid peroxides and mycotoxins, in addition to the suspicious of the presence of high levels of hydrocyanic acid and phytates, which would be countered by dietary supplementation with DL-methionine and phytase.

The impact of inclusion of the kernel cake as substitute for concentrate in broiler rations on the broiler live weight and average weekly increase is presented in (Table 4). There have been significant differences among bird groups in feed intake and live body weight. The heaviest live weight (1632.2 g) was recorded in group C and lighter live weight (511.9 g) was in group E and that may be due to differences in feed intake. These findings are consistent with those reported by Cosby DE, et al. [14], who found that the presence of these substances that act as inhibitory to feed intake impede growth and hinder the utilization of nutrients in birds and must be removed and disposed of for the desired production rates. It was also found that the average weekly gained weight was highest (375.8 g) in group I and lower (104.9 g) in C, and that may be due to the effect of source of protein on the amount of feed intake in chickens. The results of this study are similar with findings reported by Harper AE [15], who reported that change of protein source could result in a change in the content of amino acids of the feed leading to an imbalance in feed intake very quickly in the chicken. That was shown in the decline in growth that was followed by a change of the dietary protein. The decreased weight gain was not the result of direct response to that change of protein source but as much as it was a reflection of the content of amino and essential fatty acids (Table 2).

Similar results were obtained by Mthiyane MN, et al. [13] who stated a significant decrease in the live weight (P < 0.001), plucked weight (P < 0.001), dressed weight (P < 0.001), liver weight (P < 0.001) and neck weight (P < 0.05) of broilers as the level of MSC increased in the diet also Mlambo V, et al. [16] also observed that dietary MSC supplementation significantly decreased the live weight, dressed weight, dressing percentage, length of feathers, as well as weights of the wing, breast, thigh, drumstick, shank, abdominal fat, liver, gizzard, heart and intestines in broilers.

Conclusion

The study showed that Sclerocarya birrea kernel cake contained a high proportion of amino acids, crude protein and ether extract. Hence it was concluded that kernel meal might be used as substitute for super-concentrate in broiler rations to reduce feeding cost taking in consideration that it contained some anti-nutritional factors such as phytates, tannins and saponins.

Recommendations

The study recommends more research to be conducted to elucidate effects of use of Sclerocarya birrea kernel meal as substitute for the expensive super concentrate and groundnut meat as source of protein and the role of the growth inhibitory substances found in the meat such as saponin to take advantage of these fruits that are found in great abundance and collected at very low cost.