In order to assess the impact of larval meal on guinea fowl, six iso-caloric and iso-nitrogenous diets were fed to day-old-keets ad libitum till 8 weeks of age. Water was also freely provided. The fishmeal (FM) component of the experimental diets was replaced with black soldier fly larval meal (BSFLM) in the following percentage ratios of 0-100%. Results showed that body weight gain significantly (P < 0.05) increased in all the BSFLM treatment groups compared to the control group. The final body weight of the birds at age 8 weeks differed significantly (P < 0.001). Dry matter intake varied (P < 0.001) slightly among the birds but never affected (P > 0.05) ME intake and faecal output as well as weight changes of the keets. Digestibility of dry matter and energy were not affected (P > 0.05) by the differences in diet. Organ and haematopoietic integrity were assured regardless of the protein types used as well as levels of inclusion. The results suggest that the replacement of fishmeal with BSFLM in so far as the economics of production is concerned could result in reduced feed cost for starter guinea keet judging from diets that contained 60-100% BSFLM.

Nitrous oxide (N2O) emissions from pastures can vary significantly depending on soil and environmental conditions, nitrogen (N) input, as well as the plant’s ability to take up the N. We tested the hypothesis that legume-based N sources are characterized by significantly lower emission factors than mineral N based dairy systems. Therefore, this study monitored N2O emissions for a minimum of 100 days and up to two growing seasons across a gradient of plant species diversity. Emissions were measured from both, grazed pastures and a controlled application of urine and dung using the static chamber method. About 90% of the accumulated N2O emissions occurred during the first 60–75 days. The average accumulated N2O emissions were 0.11, 0.87, 0.99, and 0.21 kg ha−1 for control, dung, urine patches, and grazed pastures, respectively. The N uptake efficiency at the excreta patch scale was about 70% for both dung and urine. The highest N2O-N emission factor was less than half compared with the IPCC default (0.3 vs. 0.77), suggesting an overestimation of N2O-N emissions from organically managed pastures in temperate climates. Plant diversity showed no significant effect on the N2O emissions. However, functional groups were significant (p < 0.05). We concluded that legume-containing pasture systems without a fertilizer addition generally appear capable of utilizing nitrogen inputs from excreta patches efficiently, resulting in low N2O emissions.

The study was conducted with the view to determine the impact of replacing fishmeal with black soldier fly larval meal (BSFLM) on growing guinea fowls. BSFLM replaced fishmeal (3% in the control diet) in the ratios of 0, 20, 40, 60, 80, and 100% to produce six dietary treatments, which were iso-caloric and iso-nitrogenous. Two hundred and forty-eight-week old guinea fowls with mean live weight of 273.2 ± 10.9 g were tagged, weighted, and randomly assigned to 24 (6 × 4) floor pens; each pen was treated as a replicate. Feed and water were provided ad libitum during the entire period, which lasted 10 weeks. Feed consumption differed among the treatment groups (P = 0.0072) with the 100% fishmeal diets recording the lowest. Daily gain was significantly (P = 0.009) higher for birds fed high BSFLM diets compared to the control (100% fishmeal diet). The inclusion of BSFLM in the diets elicited positive linear effect on weight gains of the guinea fowls (R = 0.91) with increasing concentration resulting in higher live weight gains. The feed conversion ratio (FCR) also differed between treatments (P < 0.05) but similar for the 100% fishmeal (control) and 100% BSFLM diets. Organ and haematopoitic integrity were equally assured regardless of levels of the protein sources fed to the birds. Generally, meats from birds fed 60 to 100% BSFLM and from hens were more acceptable. A study to evaluate the economics of utilising BSFLM in guinea fowl production is recommended.

Abstract. Enhancing the capacity of agricultural soils to resist soil degradation and to mitigate climate change requires long-term assessments of land use systems. Such long-term evaluations, particularly regarding low-input livestock systems, are limited. In the absence of suitable long-term experiments, this study assessed the outcome of C inputs and outputs across an array of plant functional groups in arable and permanent systems of a tropical savannah after more than 50 years of consistent land use. Soil samples were taken (0–30 cm depth) from arable crop fields, grazed–seeded grassland, cut–use permanent crops and native grassland. Soil organic carbon (SOC) stocks ranged from 17 to 64 Mg SOC ha−1 (mean ± sd = 32.9 ± 10.2 Mg ha−1). SOC stocks were lower for grazed–seeded grassland relative to cut–use grass, legume trees and shrubs. Accordingly, while the conversion of the native grassland to grazed pastures caused an estimated loss of 44 % of SOC over the period, the conversion to woody legumes resulted in slight (5 %), incremental gains. Within sown systems, nitrogen (N) availability seemed to be the most critical factor in determining the fate of the SOC stocks, with the soil N concentration and SOC being highly correlated (r – 0.86; p < 0.001). In total N, P and K were significant predictors of SOC density in the soils. Moreover, secondary plant metabolites in legumes, namely tannins, were identified as having an impact on SOC. The results from this study provide the theoretical basis for testing the hypothesis that improved soil fertility management and the use of tannin-rich plants have the potential to promote long-term SOC storage in the savannah ecological region. Our study also shows the potential of legume tree/shrub forage species as an environmentally sustainable land use option to mitigate agricultural CO2 emissions from low-input livestock systems in the grasslands of southern Ghana.