Arthur Dylan Roberts

This study examined the utilization by Black Soldier Fly (BSF) for recycling organic waste into larvae as a protein rich feed for fish and chicken farmers. Research on the black soldier fly larvae (BSFL) for waste management has gained worldwide interest, however information is needed on its practical application at smallholder level. Bioconversion units referred to as “bio-digesters” were designed to incubate, hatch, feed and harvest BSFL into its last instar life cycle. Six bio-digester units were placed in a randomized block design in an open-shed environment allowing free access for natural repopulation by BSF. A 45-day life cycle was allowed for three sampling periods for collection of BSFL and evaluation of bioconversion of fermented household kitchen waste (KW) and sweet potato silage (SPS). Average wet weight of 50.71±0.12 kg SPS and KW media was seeded at the start of each period with 215±0.12 g of 10 14-dayold BSFL. Mean harvested weight was 379.3 and 100.6 g for KW and SP...

Using greater proportions of local ingredients in poultry diets to improve profitability of small-scale farming has been a high priority in the PNG livestock sector for over 15 years. This study examined the growth and feed efficiency of Ross 308 broiler chickens fed cassava flour blended with a universal concentrate (UC+Cas) during the finishing-phase. The growth of broilers fed the UC+Cas ration (12.4 % MJ/kg ME, 22.4 % CP and 4.2 % CF) was compared to a commercial finisher diet (12.2 % MJ/kg ME, 19 % CP and 5.0 % CF) made mainly from imported ingredients. The trial was conducted on 6 smallholder village farms; each farm being considered a replicate. Broilers at 21 days-of-age were weighed and allocated to two floor pens on each farm in naturally ventilated sheds built of woven reed walls and grass-thatched roofs. Feed intake and conversion, weight gain and feed costs were measured from 22-42 day-of-age. Dry matter intake (g/day) of broilers fed the commercial fin-isher and the UC+Cas diet (99.1 vs. 97.7) were similar (P>0.05). Likewise, weight gain (g/day) for broilers fed the UC+Cas and commercial diet (21.0 vs. 20.40) and feed conversion (1.75 vs. 1.84) did not differ significantly (P>0.05). Final body weights (kg/bird) were also similar (2.50 vs. 2.49; P>0.05) except for feed costs (K/bird) which differed significantly (6.15 vs. 4.89; P<0.05) with higher costs observed for birds fed the commercial ration. The UC+Cas diet was 12.97 % cheaper, signifying a potential feed option for use by small-scale poultry enterprises to finish broiler chickens. Further evaluation is needed to verify costs and profit margins over consecutive production cycles.

The purpose of this study was to assess the growth performance of juvenile genetically improved farmed tila-pia (GIFT) on diets formulated from a locally developed high-protein feed concentrate blended with cassava or sweetpotato. A total of 240 mixed-sex fingerlings were randomly assigned to four dietary treatments: (1) cassava + concentrate (CaC); (2) formulated standard diet (FSTD); (3) sweetpotato, cassava, cassava leaf + concentrate (CaLC); and (4) sweetpotato + concentrate (SPC). All diets were prepared as dry-milled products pelleted into 4 mm pellets. The fingerlings were reared for 84 days in twelve 250 L circular fibreglass tanks maintained in a recirculation aquaculture system. Each dietary treatment had three replicates with 20 fingerlings per tank. The results showed no significant differences in biomass gain among fish fed the FSTD, SPC and CaC diets, but significant differences for fish fed on CaLC (P < 0.05). In terms of feed intake, fish fed FSTD, SPC, CaC and CaLC show significant differences from each other (P < 0.05). There were significant differences in the feed conversion ratio (FCR) of fingerlings fed FSTD, SPC and CaC (P < 0.05), while the FCR of those fed CaLC was not significantly different from that of fish fed CaC but was significantly different from those of fish fed FSTD and SPC (P < 0.05). The results indicate that diets made from cassava or sweet-potato blended with feed concentrate will provide good fish yield and reduce costs.

Growth performance of juvenile genetically improved farmed tilapia (GIFT) fed diets with two levels of rice bran or a high-energy broiler concentrate mixed with cassava meal Abstract This paper examines the use of rice bran and cassava meal in feeds for genetically improved farmed tilapia (GIFT). Two isoproteic (28% crude protein) and isoenergetic (17 MJ/kg) feeds were formulated using fish-meal, cassava meal and millrun to contain either 20% rice bran (RB20) or 40% rice bran (RB40). These diets were compared to a diet formed by blending high-energy universal feed concentrate suitable for use with broilers , layers or pigs with 31% cassava meal (HEC+CAS; 24% crude protein, 17 MJ/kg). The three feeds were fed to mixed-sex juvenile GIFT (3.80 ± 1 g) for 12 weeks. Fish were reared in 100 L freshwater tanks at a temperature of 29°C and each dietary treatment was randomised to four replicate tanks. Each tank contained four fish. After 12 weeks there was no significant difference in the weight gain or feed conversion ratio (FCR) of tilapia fed the different diets (P < 0.05). However, fish fed the HEC+CAS diet were heavier (36.7 g) than fish fed the RB40 (29.1 g) and RB20 (27.9 g) diets and had a better FCR. The protein efficiency ratio (PER) of fish fed HEC+CAS was significantly better (1.85) than fish fed the RB20 (1.15) and RB40 diets (1.17). The slight increase in weight gain and improvement in FCR and PER of GIFT fed the HEC+CAS diet might be a function of the lower protein:energy ratio of this diet or the additional micronutrients contained in the universal concentrate. Nonetheless, the fish fed on diets RB20 and RB40 achieved similar weight gains, FCR and PER, suggesting rice bran is as useful an energy source as cassava meal for this species. Further research on the performance and economics of using rice bran in grow-out diets for GIFT in Papua New Guinea is recommended. Moreover, the research should focus on larger scale trials that formulate test feeds on a digestible nutrient and energy basis and that apply satiation feeding strategies.