The aim of the study was to evaluate the use of three by-products as growing substrates for Hermetia illucens (Black Soldier Fly (BSF)) larvae: okara, maize distiller, brewer’s grains, and a control hen diet. The study focused on larval growth and bioconversion performance, production of methane by larvae and environmental burden of larvae production, using Life Cycle Assessment (LCA) on a lab scale. Chemical composition of substrates differed: okara had the highest crude protein and ether extract contents, while brewer’s grains showed the highest fiber content. Larvae fed on a hen diet and maize distiller exhibited the highest final weights (2.29 and 1.97 g, respectively). Larvae grown on okara showed the highest indexes for waste reduction and efficiency of conversion of the ingested feed. The BSF larvae did not produce any detectable traces of CH4. LCA evaluation showed that larvae production on a hen diet resulted in the most impact for most of environmental categories, for the inclusion of soybean meal in the diet (for climate change, 5.79 kg CO2 eq/kg dry larvae). Feed production activities resulted in the main contributions to environmental impact. In order to compare the larvae production obtained on all substrates, an environmental impact was attributed to okara and brewer’s grain through a substitution method, and, by this approach, the best sustainable product resulted from the larvae grown on the maize distiller.

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A large-scale survey was conducted on 173 dairy goat farms in Northern Italy to provide an updated view on farm management practices and to investigate relations among management factors, herd traits and milk yield and quality with particular focus on milk somatic cell count (SCC) and milk fat/protein reversion syndrome. Monthly individual milk analyses (fat, protein and lactose percentages, SCC) and bulk tank milk analyses (fat, protein and lactose percentages, standard plate count (SPC), urea and casein) from 91 farms out of the 173 farms were collected for a year. Farming systems showed wide variability and were characterised by the coexistence of intensive farms adopting advanced technologies and extensive traditional ones. Average milk production was 1.25 kg/milking with high variability, significantly influenced by days in milk, month of kidding, herd size and parity. Out-of-season breeding was predicted to cause a slight reduction of milk production. The reversion syndrome between milk fat and protein contents affected more than half of samples. It worsened after 100 d of lactation and occurred earlier during lactation when kidding was in the late season (April-June) compared to kidding in the first months of the year. The defect was associated with high SCC in milk. The yearly average milk SCC was 5.8 log 10 cells/mL; it was higher at the end of lactation and in goats kidding in the late season. A negative relationship between SCC and milk yield was found with an estimated loss of 0.23 kg per milking for each additional point of log 10 SCC.

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