Poultry farms in subtropical and tropical countries are potential consumers of housefly maggot meal. While initial investigations were carried out in the United States, most of the studies have been or are being done in Sub-Saharan Africa, especially Nigeria, and to a lesser extent in Asia.
Energy and digestibility
There are limited data on the metabolizable energy value of housefly maggots (14.2 MJ/kg DM, Pretorius, 2011; 17.9 MJ/kg DM, Zuidhof et al., 2003). The energy value is highly dependent on the fat content and on the amount of fibre in the housefly maggot meal. Total tract amino acid digestibility is high (95%, Zuidhof et al., 2003; 91%, Pretorius, 2011).
Live maggots can be a valuable supplement to the diet of rural chickens. In Ghana, the supplementation of 30-50 g/d/bird of live maggots to scavenging backyard chickens resulted in higher growth rate (until the 5th month), clutch size, egg weight, number of eggs hatched, and chick weight (Dankwa et al., 2002). A similar preliminary test in Togo was also positive, as the chickens seemed particularly fond of moving larvae (Ekoue et al., 2000).
Maggot meal has been included in broiler diets as a replacement for conventional protein sources, notably fish meal. Most trials indicate that partial or even total replacement of fish meal is possible, though the optimal inclusion rate is generally lower than 10%. Higher rates have resulted in lower intake and performance, perhaps due to a decrease in palatability, as the darker colour of the meal may be less appealing to chickens (Atteh et al., 1993; Bamgbose, 1999). Methionine supplementation is recommended (Bamgbose, 1999).
Trials on broilers and the obtained results are summarized in the table below:
||25-day old broilers
||Maggot meal replacing 0-100% groundnut cake
||Replaced 100% groundnut cake (22% diet as fed) without adverse effect on performance. Non-significant trend to lower feed intake and weight gain at 75 and 100% substitution.
||120-day old broilers
||4:1 mixture of dried cassava peels and maggot meal replacing 0-100% maize grain
||Mixture of cassava peels and maggots replaced 50% maize (29% diet as fed) in order to save cost.
||Adesina et al., 2011
||0-56 days broilers
||Maggot meal replacing 75% fish meal protein
||No adverse effect on performance and higher economic returns.
||Akpodiete et al., 2000
||0-5 weeks broilers
||Maggot meal replacing 0-100% fish meal
||Replaced up to 33% fish meal (9% diet as fed) without adverse effects on intake and weight gain. At higher rates, lower intake could be associated to the darker colour of the maggot diets.
||Atteh et al., 1993
||3-week old broilers
||Maggot meal replacing 0-100% fish meal protein
||Could replace up to 25% fish meal protein (1.17% diet as fed) for profitable results.
||Awoniyi et al., 2003
||0-8 weeks broilers
||Maggot meal replacing 0-100% meat and bone meal
||Replaced up to 100% meat and bone meal (8% diet as fed) if the diet was supplemented with methionine.
||21-day old broilers
||Maggot meal compared to fish meal, meat and bone meal and soybean meal
||Was included at up to 10% in the diet with no adverse effect on intake, body weight, feed conversion and palatability.
||Cadag et al., 1981
||0-2 weeks broilers
||Pupae meal replacing 100% soybean meal
||Replaced soybean meal with no effect on gain, intake and feed efficiency.
||Calvert et al., 1969
||0-3 and 3-5 weeks broilers
||Maggot meal at 0-20% in a balanced diet
||Maggot supplementation caused increased live weight gain but had no effect on the feed conversion ratio. The 10-15% maggots diet gave the best weight gain for the 4-5 weeks broilers and increased dressing percentage, weight of breast muscle and thigh muscle, muscle lysine and tryptophan levels.
||Hwangbo et al., 2009
||0-24 days broilers
||Maggot meal at 7% in a balanced diet replacing fish meal
||Identical growth performance, feed conversion ratio and meat composition; higher dressing percentage in maggot-fed broilers.
||Inaoka et al., 1999
||35-day old broilers
||Maggot meal replacing 0-50% fish meal
||Could replace 50% fish meal (2% diet as fed) with higher performance and economic returns
||Okah et al., 2012
||0-35 days broilers
||Maggot meal included at 10-50% in the diet
||The 25% maggot meal diet yielded better live weights, feed intake and daily gain when compared to the 25% fish meal diet in the growth phases. Chicks that received either the 10% house fly larvae meal or 10% fish meal supplementation produced significantly heavier carcasses and breast muscle portions than the chicks that received the commercial maize:soybean meal diet. No treatment differences were found regarding breast and thigh muscle colour or pH.
||Yellow dwarf 8-63 days broilers
||Maggot meal included at 4.4% in the diet
||Supplementation with maggot meal enhanced feed intake and average daily gain at 8-21 days with no negative effect on the slaughter performance and meat quality. Performance differences were non significant in the later stages.
||Ren et al., 2011
||0-42 days broilers
||Maggot meal replacing 0-15% fish meal (0-6.75% of diet) in starter diets and 0-100% (0-2% of diet) in finisher diets
||The replacement of fish meal with maggot meal starter and grower finisher diets resulted in higher weight gains and comparable carcass yields.
||Téguia et al., 2002
||0-7 weeks broilers
||Pupae meal included at 28% in the diet, replacing other protein sources (soybean meal, fish meal and meat and bone meal)
||No difference in growth rate, carcass quality and taste but lower final weight and feed intake for pupae-fed broilers.
||Teotia et al., 1973
||0-4 weeks broilers
||Pupae meal included at 8% in the diet, replacing fish meal and meat and bone meal
||No difference in growth rate.
||Teotia et al., 1973
In a seven-month layer feeding trial, maggot meal replaced meat and bone meal, the results indicating that maggot meal increased egg yield and hatchability (Ernst et al., 1984). In 50-week old laying hens, maggot meal could replace 50% of fish meal protein (5% diet as fed) without adverse effects on egg production and shell strength. However, 100% replacement was deleterious to hen-day production (Agunbiade et al., 2007).