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Manure nitrogen (N) from cattle contributes to nitrous oxide and ammonia emissions and nitrate leaching. Measurement of manure N outputs on dairy farms is laborious, expensive, and impractical at large scales; therefore, models are needed to predict N excreted in urine and feces. Building robust prediction models requires extensive data from animals under different management systems worldwide. Thus, the study objectives were (1) to collate an international database of N excretion in feces and urine based on individual lactating dairy cow data from different continents; (2) to determine the suitability of key variables for predicting fecal, urinary, and total manure N excretion; and (3) to develop robust and reliable N excretion prediction models based on individual data from lactating dairy cows consuming various diets. A raw data set was created based on 5,483 individual cow observations, with 5,420 fecal N excretion and 3,621 urine N excretion measurements collected from 162 in vivo experiments conducted by 22 research institutes mostly located in Europe (n = 14) and North America (n = 5). A sequential approach was taken in developing models with increasing complexity by incrementally adding variables that had a significant individual effect on fecal, urinary, or total 2manure N excretion. Nitrogen excretion was predicted by fitting linear mixed models including experiment as a random effect. Simple models requiring dry matter intake (DMI) or N intake performed better for predicting fecal N excretion than simple models using diet nutrient composition or milk performance parameters. Simple models based on N intake performed better for urinary and total manure N excretion than those based on DMI, but simple models using milk urea N (MUN) and N intake performed even better for urinary N excretion. The full model predicting fecal N excretion had similar performance to simple models based on DMI but included several independent variables (DMI, diet crude protein content, diet neutral detergent fiber content, milk protein), depending on the location, and had root mean square prediction errors as a fraction of the observed mean values of 19.1% for intercontinental, 19.8% for European, and 17.7% for North American data sets. Complex total manure N excretion models based on N intake and MUN led to prediction errors of about 13.0% to 14.0%, which were comparable to models based on N intake alone. Intercepts and slopes of variables in optimal prediction equations developed on intercontinental, European, and North American bases differed from each other, and therefore region-specific models are preferred to predict N excretion. In conclusion, region-specific models that include information on DMI or N intake and MUN are required for good prediction of fecal, urinary, and total manure N excretion. In absence of intake data, region-specific complex equations using easily and routinely measured variables to predict fecal, urinary, or total manure N excretion may be used, but these equations have lower performance than equations based on intake.

Can the larvae of the black soldier fly replace soybean in the diet of broilers?

Beeinflusst der Ersatz von Sojakomponenten durch Larvenmehl und -fett der Hermetia illucens die Leistung von Bio-Broilern?

Insects in general and especially the larvae of the black soldier fly (BSF) are globally discussed as a possible replacement for soybean in animal nutrition. However, information about their feeding value is scarce. Therefore an experiment was carried out with organic broilers where soybean cake and oil (S) was replaced by defatted meal and fat of BSF larvae grown on two different substrates (A/B). 80 Hubbard S757 broilers were kept in pairs and fattened from day 15 to 63/64 of life with one of the five following diets: a positive control (S/S, protein meal/oil, 21% CP) complying with recommendations for this broiler type, a negative control (SS-, 18% CP), a diet with BSF meal A and fat A (AA, 17% CP), a diet with BSF meal A and BSF fat B (AB, 17% CP) or a diet with BSF meal B (BB, 17% CP, no extra fat). Diets SS-, AA, AB and BB theoretically induced a protein deficiency to determine whether the protein value of the insect material is comparable to that of soybean. One animal per pair was analysed for carcass and meat quality. The average daily gains (g) were 27.1, 20.4, 27.5, 26.4 and 19.9 for SS, SS-, AA, AB and BB (SSand BB, P

Journal of Insects as Food and Feed, 6 (S1), ISSN:2352-4588

Soybean meal and oil are major protein and fat sources in diets for poultry. However, their use in animal feeding is controversially discussed due to potentially negative environmental and social impacts. In response, an intensive search is ongoing looking for dietary protein sources which are more sustainable and are also not competing with human food production. Among the alternative feeds discussed, there is a great interest in integrating insects into livestock nutrition as a replacement for soybean. Still the research on feeding value of insect protein meal and fat of larvae grown on different substrates is scarcer. Among the insects, the greatest potential is seen in the larvae of the Black Soldier Fly (BSF). So far, studies concentrated only on the defatted larval meal whereas the large amount of the larvae fat is only used for industrial purpose. Therefore, the aim of the present study was to investigate the possibility to replace soybean cake and oil in the organic feed of laying hens by meal and oil from larvae reared on different substrates. For this purpose 50 Lohmann Brown Classic hens, being 29 weeks old, were allocated to five dietary treatments in a randomized design. The diets differed in the ingredients used as main protein and fat sources. The control diet contained soybean cake and soybean oil while the four experimental diets were based on different defatted BSF larvae meal and fat sources. Both BFS batches were reared on preconsumer food waste, but the larval materials still largely differed because of differently intensive fat removal and refining techniques applied. The laying hens were housed individually in enriched 80 x 80 x 80 cm cages under controlled temperature, light and humidity conditions. Feed intake, laying performances and egg weight were determined daily and the hens were weighed once per week within a period of 26 days. Feed intake, body weight and laying performance did not differ significantly between the five treatments. There were diet effects on egg weight, egg mass and feed conversion efficiency (P < 0.05). Egg weight and egg mass were most favorable with the diet containing the protein meal of the larvae intensively defatted and soybean oil not being replaced by larval fat. The feed intake of all groups was within the range recommended and as expected for hens of this age and breed. The results indicate that the insect meals and fats were well palatable and consequently the insect-based materials showed a high potential for their implementation in laying hen production. In order to underline the results of this experiment, various parameters as the egg quality or feed digestibility are currently under investigation.

The demand for animal products and, therefore, protein and energy to feed livestock is expected to increase in the next 30 years. Currently one of the main protein sources is soybean, especially processed to soybean meal (cake in case of organic agriculture) and soybean oil. Their use in animal nutrition is controversially discussed due to potentially negative environmental and social impacts. For this reason, an intensive search for dietary protein sources is ongoing which are more sustainably produced and do not compete with human food production. Among the alternative feeds discussed, there is a great interest in the integration of insects into animal feeding as a replacement for soybean, but research on the feeding value of insect protein meal and fat of larvae grown on different substrates is scarce. Among the insect species, the greatest potential is seen in the Black Soldier Fly larvae (BSF). So far, studies have focused only on the defatted larval meal whereas the large amount of fat in the larvae is only used for industrial purpose. Therefore, the aim of the doctoral project is to investigate the possibilities and limitations of including both types of insect materials into organic diets for laying hens and broilers. For this purpose, two work packages will be carried out at the ETH research station AgroVet-Strickhof, Lindau, Switzerland, both tested in an organic broiler type and in layers. In the first work package, soybean protein and oil in the diet will be replaced by insect protein and fat that was produced on two different legally permitted substrates. In the second work package, the transfer of contaminants (heavy metals, mycotoxins) from substrates, e.g. household waste, to larval protein meal and fat and further to meat and eggs will be analysed. In both work packages, traits of performance, protein and energy utilization, as well as carcass, meat and egg quality are measured. For this purpose the animals are kept in special cages, that make the sampling per animal (laying hens) or per two animals (broilers) possible. This allows to provide information about the value of larval protein and fat compared to soybean protein and oil, as well as the degree of transfer of contaminants through the production chain.

In this study the utility of insects as ingredients of organic diets for laying hens as a potential novel and more sustainable protein and energy source was investigated. The used insect material (protein meal and larval fat) was obtained from Black Soldier Fly (BSF) larvae reared on two permitted substrates (primarily grain-based agrifood sidestreams and preconsumer foodwaste, respectively) and then integrated in the diets of laying hens to completely replace soybean cake and oil. Over the feeding period of seven weeks various performance characteristics, protein and energy utilization, as well as egg quality were analyzed. The results show that replacement of soy meal and oil by insect materials did not negatively affect performance of the hens or the quality of the eggs. It remains to be investigated if and to which degree unfavorable saturated fatty acids, characteristic for BSF, are incorporated in the egg