Organic medium-growing chickens fed live black soldier fly larvae: A welfare improvement study.

The overall beneficial effect of live black soldier fly larvae (BSFL) on the welfare of broiler chickens, turkeys, and laying hens has already been discussed in the literature. However, scant information is available regarding the benefits of feeding live BSFL to medium-growing chicken hybrids reared under organic/free-range conditions, and whose welfare is frequently cited as being inadequate. The aim of this research was to advance our knowledge of this topic. To this end, 240 label naked neck birds (Hubbard JA57 hybrid) were assigned, at 21 days of age, to four experimental groups (6 replicates/treatment, 10 chickens/replicate), created according to sex (M/F) and the provision of a 10% live BSFL dietary supplementation (control males, control females, larvae males, and larvae females), and raised until 82 days of age. We performed behavioural observations, a tonic immobility test, and an avoidance distance (AD) test. We assessed feather damage and cleanliness, hock burn, footpad dermatitis, and skin lesion scores, and determined the concentration of excreta corticosterone metabolites (ECM) and the heterophile to lymphocyte heterophile/lymphocyte (H/L) ratio. The behavioural observations demonstrated increased physical and foraging activity (p < 0.05) in the live BSFL administered groups compared with C ones, providing valuable data on the explorative and recreational behaviour of this chicken genotype. The results also evidenced the usefulness of live BSFL as a fear reducer in females, as those receiving the BSFL supplement moved closer to the operator during the AD test (p < 0.01). No physical injuries or damage were observed on the birds, regardless of whether they received the BSFL supplementation or not. The ECM were unaffected by BSFL supplementation, while the H/L ratio was higher in the larvae groups than in the control ones (p = 0.050). In conclusion, live BSFL provision could constitute a powerful tool for improving life quality in medium-growing chickens. Further research is required to clarify the stress modulation role of live BSFL on poultry production.

Does the provision of live black soldier fly and yellow mealworm larvae improve Muscovy duck welfare?

BACKGROUND: The provision of environmental enrichments to Muscovy ducks could reduce the expression of the aggressive behaviors. The aim of the present study was to evaluate the effects of black soldier fly (BSF) and yellow mealworm (YM) live larva provision on Muscovy duck performance, excreta corticosterone metabolites (ECM), behavior, and blood parameters. METHODS: A total of 126 3-day-old female Muscovy ducklings were allotted to 18 pens (6 replicates/treatment, 7 birds/pen) and assigned to 3 experimental treatments: a control group fed commercial feed, and two experimental treatments fed commercial feed plus the 5% (based on the expected daily feed intake, as fed basis) of BSF and YM live larvae (BSF and YM groups, respectively). A two-phase feeding program was applied: starter (from 3 to 31 days of age) and grower-finisher (from 32 to 55 days of age). The live weight, average daily gain, average daily feed intake, and feed conversion ratio were calculated. Larva consumption times were collected, and video recordings were performed during 3 periods (P) each day: the hour before (P1), during (P2), and after (P3) the larva administration. ECM were evaluated at 3, 31, and 55-day-old. Finally, the total red and white blood cell counts, serum proteins, lipids, and liver and renal function serum enzymes were evaluated on 12 birds/treatment. RESULTS: The experimental treatment did not affect the growth performance of the birds (P > 0.05). Larva consumption times were always similar between the two insect species, except at 14-18 days of age, were BSF larvae were consumed faster than YM larvae (P < 0.001). The birds showed less walking activity during P2, and preening behavior increased in YM birds during P3. The C birds increased the attack behavior over the weeks (P < 0.05). During weeks 1-3 the YM group reduced the attack frequency (P1 > P3; P < 0.05). Finally, the provision of live BSF and YM larvae significantly reduced the ECM at 55 days of age and the heterophil to lymphocyte ratio (P < 0.05). CONCLUSIONS: Live BSF and YM larva supplementation in Muscovy duck improves duck welfare, without impairing birds' growth performance.

Full-fat insect meals in ruminant nutrition: in vitro rumen fermentation characteristics and lipid biohydrogenation.

BACKGROUND: The most used protein sources in ruminant nutrition are considered as having negative impacts in terms of environmental sustainability and competition with human nutrition. Therefore, the investigation of alternative and sustainable feedstuffs is becoming a priority in ruminant production systems. RESULTS: This trial was designed to evaluate eight full-fat insect meals (Acheta domesticus - ACD; Alphitobius diaperinus - ALD; Blatta lateralis - BL; Gryllus bimaculatus - GB; Grylloides sygillatus - GS; Hermetia illucens - HI; Musca domestica - MD; and Tenebrio molitor - TM) as potential protein and lipid sources in ruminant nutrition. Fermentation parameters and fatty acids (FA) of rumen digesta after 24-h in vitro ruminal incubation of the tested insect meals were measured and compared with those of three plant-based meals (soybean meal, rapeseed meal and sunflower meal) and fishmeal (FM). Similarly to FM, the insect meals led to a significantly lower total gas production (on average, 1.75 vs. 4.64 mmol/g dry matter-DM), methane production (on average, 0.33 vs. 0.91 mmol/g DM), volatile FA production (on average, 4.12 vs. 7.53 mmol/g DM), and in vitro organic matter disappearance (on average, 0.32 vs. 0.59 g/g) than those observed for the plant meals. The insect meals also led to lower ammonia of rumen fluid, when expressed as a proportion of total N (on average, 0.74 vs. 0.52 for the plant and insect meals, respectively), which could be an advantage provided that intestinal digestibility is high. Differences in ruminal fermentation parameters between the insect meals could be partially explained by their chitin, crude protein and ether extract contents, as well as by their FA profile. In particular, high content of polyunsaturated FA, or C12:0 (in HI), seems to partially inhibit the ruminal fermentations. CONCLUSIONS: The tested full-fat insect meals appear to be potentially an interesting protein and lipid source for ruminants, alternative to the less sustainable and commonly used ones of plant origin. The FA profile of the rumen digesta of ACD, ALD, GB, GS and TM, being rich in n-6 polyunsaturated FA, could be interesting to improve the quality of ruminant-derived food products.

Are Local Dairy Products Better? Using Principal Component Analysis to Investigate Consumers' Perception towards Quality, Sustainability, and Market Availability.

Consumers are increasingly aware of the benefits of local foods in terms of quality, sustainability, animal welfare, and safety. This research addresses two main questions: (i) is the perception towards sustainability aspects of local dairy products related to individuals' preferences for milk and cheese quality aspects? (ii) are these perceptions related to people's socio-demographic characteristics? For this purpose, a choice experiment was conducted online in Apulia (South-East Italy) involving a sample of 543 respondents. A Principal Component Analysis (PCA) was applied to analyze the consumer opinion related to dairy products' quality attributes, sustainability, and availability on the market. From the PCA, four main components (accounting the 64.5% of the total explained variance) were defined, highlighting non-overlapping choice styles of consumers, distinguished by attitudes primarily based on quality attributes of dairy products rather than sustainability characteristics or perceived higher quality of local products. Furthermore, the Availability request component described the consumer need for higher availability and/or visibility of local dairy products on the market. The effect of gender, age, and educational status of individuals emerged as significantly important for the resulting component definitions. The obtained results clearly suggest the need to increase the efficiency of communication strategies concerning local dairy products, as well as local dairy products' availability and visibility on the markets.

Inclusion of Cocoa Bean Shell in the Diet of Dairy Goats: Effects on Milk Production Performance and Milk Fatty Acid Profile.

The use of agro-industrial by-products in animal nutrition is a promising strategy to reduce the food-feed competition, the diet cost at farm level and the environmental impact of animal-derived food production. In this study, the suitability of cocoa bean shell (CBS), a by-product of the cocoa industry, as a feed ingredient in the diet of dairy goats was evaluated, with a focus on the related implications on feed intake, milk yield, milk main constituents, and fatty acid (FA) profile of milk fat. Twenty-two Camosciata delle Alpi goats were divided into two balanced groups. All the goats were fed mixed hay ad libitum. The control group (CTRL; n = 11) also received 1.20 kg/head × day of a commercial concentrate, while in the experimental group (CBS; n = 11) 200 g of the CTRL concentrate were replaced by the same amount of pelleted CBS. The total dry matter intake of the goats was reduced by the dietary inclusion of CBS (P ≤ 0.01). The milk yield, as well as the milk fat, protein, and casein contents and yields were unaffected by the treatment. Milk from the CBS-fed goats showed decreased urea content when compared to the CTRL group (P ≤ 0.001). Milk from the CBS group of goats also showed increased concentrations of total branched-chain FA (both iso and anteiso forms; P ≤ 0.001) and total monounsaturated FA (P ≤ 0.05), as well as a decreased ∑ n6/∑ n3 FA ratio (P ≤ 0.05). De novo saturated FA, total polyunsaturated FA, total conjugated linoleic acids, and the majority of ruminal biohydrogenation intermediates remained unaffected by the dietary treatment. These results suggest that CBS can be strategically used as an alternative non-conventional raw material in diets intended for lactating goats, with no detrimental effects on their milk production performance. The use of CBS in goat nutrition may be hindered by the presence of theobromine, a toxic alkaloid. Special attention is needed by nutritionists to avoid exceeding the theobromine limits imposed by the current legislation. Detheobromination treatments are also suggested in literature to prevent toxic phenomena.

Carcass Yields and Meat Composition of Male and Female Italian Slow-Growing Chicken Breeds: Bianca di Saluzzo and Bionda Piemontese.

The slaughter performance and meat quality of two native Italian chicken breeds, Bionda Piemontese (BP, n = 64) and Bianca di Saluzzo (BS, n = 64), were investigated. Two-way ANOVA, considering breed, sex, and their interaction, was used to compare the properties of birds slaughtered at 5, 6, 7, and 8 months of age. Subsequently, data were analyzed using one-way ANOVA and the Duncan test to evaluate the differences between slaughter ages. The BP breed produced a better carcass yield than BS at 5, 7, and 8 months of age (p < 0.05). Breast moisture and crude protein contents were influenced by gender, and were higher in males than in females (p < 0.05). By contrast, the crude fat content was higher in females than in males (p < 0.05). The saturated fatty acid content of breast meat increased as the birds aged in both breeds (p < 0.05). The polyunsaturated fatty acid content of both breast and thigh meat was higher in males than in females (p < 0.001 and p < 0.05, respectively). In general, slaughtering at 7 months was associated with the best slaughter and meat quality characteristics in both breeds. Moreover, from a nutritional point of view, the characteristics of the meat from male birds were preferable to those of meat from females.

Black soldier fly larvae used for environmental enrichment purposes: Can they affect the growth, slaughter performance, and blood chemistry of medium-growing chickens?

Introduction: This research has been aimed at evaluating the effects of live black soldier fly larvae (BSFL) (Hermetia illucens) on the growth, slaughtering performance, and blood parameters of medium-growing chickens. Methods: A total of 240, 28-day-old, Label Rouge Naked Neck chickens were allotted to four experimental groups, according to the gender (males-females) and to the absence (control group, C) or presence (larvae group, L) of a dietary supplementation with 10% live BSFL, on the basis of the expected average daily feed intake (ADFI) (6 replicates/diet, 10 chickens/replicate). The birds were weighed weekly, and the feed consumption was recorded to calculate the average live weight, feed conversion ratio (FCR), average daily gain (ADG), and the ADFI. At 82 days of age, 2 birds/replicate (12 birds/diet) were selected and slaughtered. The blood samples were collected, and the carcass traits (carcass, breast, thigh, and organ weights and yields) were assessed. Results and discussions: Overall, the administered live BSFL did not impair the growth and slaughtering performance, or the blood traits, while the C females showed a better FCR than the treated ones (P < 0.05). The live BSFL consumption time was longer for the females than for the males (P < 0.001). The weight of the immune organs (spleen and bursa of Fabricius) increased as the live BSFL supplementation increased (P < 0.05). Furthermore, the provision of live BSFL reduced the gamma glutamyl transferase (GGT, U/l) activity content in the blood (P < 0.05). Finally, both the leukocytes (%) and the monocytes (%) were more abundant in the C groups than in the larvae ones (P < 0.05 and P < 0.01, respectively). In short, the supplementation of live BSFL can be used successfully as an environmental enrichment, without affecting the growth performance of male birds. Furthermore, the immune organ activity could be enhanced by the provision of live BSFL.

Feasibility and Reliability of the AWIN Welfare Assessment Protocol for Dairy Goats in Semi-extensive Farming Conditions.

The aim of this study was to test the feasibility and reliability of the Animal Welfare Indicators (AWIN) protocol for welfare assessment of dairy goats when applied to semi-extensive farming conditions. We recruited 13 farms located in the NW Italian Alps where three assessors individually and independently applied a modified version of the AWIN welfare assessment protocol for goats integrated with some indicators derived from the AWIN welfare assessment protocol for sheep. The applied protocol consisted of nine individual-level (body condition score, hair coat condition, abscesses, overgrown claws, udder asymmetry, fecal soiling, nasal discharge, ocular discharge, and improper disbudding) and seven group-level (severe lameness, Qualitative Behavior Assessment-QBA, thermal stress, oblivion, Familiar Human Approach Test-FHAT, synchrony at grazing, synchrony at resting) animal-based indicators. On most farms, the level of welfare was good. Many of the considered welfare problems (overgrown claws, fecal soiling, discharges, and thermal stress) were never recorded. However, oblivion, severe lameness, hair coat condition and abscesses were detected on some farms, with percentages ranging from 5 to 35%. The mean percentage of animals with normal body condition was 67.9 ± 5.7. The level of synchronization during resting was on average low (14.3 ± 7.2%). The application of the whole protocol required more than 4 h/farm and 3 min/goat. The inter-observer reliability varied from excellent (udder asymmetry, overgrown claws, discharges, synchrony at resting, use of shelter) to acceptable (abscesses, fecal soiling, and oblivion), but insufficient for hair coat condition, improper disbudding, synchrony at grazing, QBA. Differences in background of the assessors and feasibility constraints (i.e., use of binoculars in unfenced pastures, individual-level assessment conducted during the morning milking in narrow and dark pens, difficulties when using the scan and instantaneous sampling method due to the high number of animals that moved at the same time) can affect the reliability of data collection. Extensive training seems necessary for properly scoring animals when applying the QBA, whereas the FHAT to evaluate the Human-Animal Relationship of goats at pasture seems promising but needs to be validated. Indicators that evaluate the synchrony of activities require to be validated to identify the best moment to perform the observations during the day.

Evaluation of Inter-Observer Reliability of Animal Welfare Indicators: Which Is the Best Index to Use?

This study focuses on the problem of assessing inter-observer reliability (IOR) in the case of dichotomous categorical animal-based welfare indicators and the presence of two observers. Based on observations obtained from Animal Welfare Indicators (AWIN) project surveys conducted on nine dairy goat farms, and using udder asymmetry as an indicator, we compared the performance of the most popular agreement indexes available in the literature: Scott's π, Cohen's k, kPABAK, Holsti's H, Krippendorff's α, Hubert's Γ, Janson and Vegelius' J, Bangdiwala's B, Andrés and Marzo's ∆, and Gwet's γ(AC1). Confidence intervals were calculated using closed formulas of variance estimates for π, k, kPABAK, H, α, Γ, J, ∆, and γ(AC1), while the bootstrap and exact bootstrap methods were used for all the indexes. All the indexes and closed formulas of variance estimates were calculated using Microsoft Excel. The bootstrap method was performed with R software, while the exact bootstrap method was performed with SAS software. k, π, and α exhibited a paradoxical behavior, showing unacceptably low values even in the presence of very high concordance rates. B and γ(AC1) showed values very close to the concordance rate, independently of its value. Both bootstrap and exact bootstrap methods turned out to be simpler compared to the implementation of closed variance formulas and provided effective confidence intervals for all the considered indexes. The best approach for measuring IOR in these cases is the use of B or γ(AC1), with bootstrap or exact bootstrap methods for confidence interval calculation.

Dietary inclusion of a partially defatted black soldier fly (Hermetia illucens) larva meal in low fishmeal-based diets for rainbow trout (Oncorhynchus mykiss).

BACKGROUND: Recent investigations highlighted that Hermetia illucens (BSF) larva meal can be a valuable alternative protein source for aquafeed production. In this study, in substitution of fishmeal, we used increasing inclusion levels of a partially defatted BSF larva meal in low fishmeal-based diets for rainbow trout (Oncorhynchus mykiss Walbaum) and we evaluated the related implications in terms of growth performance, physical characteristics, proximate and fatty acid (FA) compositions of the fillets, gut and liver histology, and diet digestibility. In a 131-day trial, 576 fish (100.1 ± 9.29 g) were randomly allotted to 24 tanks (24 fish/tank, 4 replicates/treatment). Six experimental diets were produced to have partial replacement of fishmeal (0, 10%, 20%, 30%, 40% and 50%) by increasing levels of BSF meal (0% [BSF0], 3% [BSF3], 6% [BSF6], 9% [BSF9], 12% [BSF12] and 15% [BSF15] on as fed basis, respectively). RESULTS: No differences were observed among the treatments for all the considered growth performance parameters. The viscero and hepato-somatic indexes showed significant differences among the treatments, with the highest values observed in the BSF15 group. No differences were recorded in terms of fillet's physical characteristics, dry matter (DM), crude protein (CP) and ether extract (EE) contents. Total saturated and monounsaturated FA increased, while polyunsaturated FA (particularly n-3 FA) decreased while increasing the HI meal inclusion in the diet. Histopathology of liver and gut was not affected, whereas, in posterior gut, villi were higher in BSF6 and BSF9 compared to BSF3 fish. The apparent digestibility of DM, CP, EE and gross energy did not vary among the treatments. CONCLUSIONS: These results suggest that a partially defatted BSF meal could be included up to 15% in low fishmeal-based diets for rainbow trout with no adverse effects on growth performance, fillet's physical characteristics, gut and liver health, and diet digestibility. On the contrary, the fillet FA composition worsened while increasing the level of BSF meal in the diet.

Comparison of In Vivo and In Vitro Digestibility in Donkeys.

We compared in vivo and in vitro dry matter (DM) and neutral detergent fiber (NDF) digestibility in donkeys using feces as microbial inoculum. Four donkeys were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. The animals were fed two types of hay, with or without flaked barley. For the in vivo procedure, total feces were collected for 6 days from each donkey; digestibility was calculated as the difference between ingested and excreted DM and NDF. For the in vitro procedure, donkey feces were buffered and used as microbial inoculum in an Ankom DaisyII Incubator; digestibility was estimated after 60 h of incubation. In vivo results showed that the addition of barley to hays did not change the digestibility values. In vivo estimates were higher than in vitro ones. The equations used to predict in vivo estimates from in vitro data were not reliable (R2 = 0.47 and 0.21; P = 0.003 and 0.078 for NDF and DM digestibility, respectively). Further studies need to evaluate different sample size and digestion times.

Evaluating the Suitability of Hazelnut Skin as a Feed Ingredient in the Diet of Dairy Cows.

Hazelnut skin (HS) was evaluated as a source of nutrients for dairy cows. In total, 26 Aosta Red Pied cows were divided into two balanced groups. All cows were fed hay ad libitum. The control group was also given 6 kg of concentrate, while the hazelnut skin group (HAZ) was given 1 kg of the same concentrate that was substituted by 1 kg of HS. The dry matter intake of the cows was reduced by the dietary inclusion of HS (p ≤ 0.001). The milk yield and main constituents were unaffected by treatment. Milk from HAZ cows showed decreased concentrations of de novo saturated fatty acids (FAs), odd- and branched-chain FA, α-linolenic acid, and long-chain n-3 FAs, as well as increased concentrations of stearic acid, oleic acid, linoleic acid, total monounsaturated FAs, trans biohydrogenation intermediates, and α-tocopherol. Replacing the concentrate with HS increased the human-inedible feed quota in the diet and improved the sustainability of milk production in terms of the food-feed competition. Our results suggest that it is possible to add economic value to organic waste from the hazelnut industry using HS as a feed ingredient for dairy cows, enhancing the feed efficiency and milk antioxidant activity and having expected impacts on the nutraceutical quality of milk fat.

Partially Defatted Tenebrio molitor Larva Meal in Diets for Grow-Out Rainbow Trout, Oncorhynchus mykiss (Walbaum): Effects on Growth Performance, Diet Digestibility and Metabolic Responses.

Insect meals are good candidates to replace fishmeal as new protein sources in aquafeeds. This study evaluated the effects of fishmeal replacement with different dietary inclusion levels of a partially defatted Tenebrio molitor (L.) larva meal (TM) on rainbow trout (Oncorhynchus mykiss Walbaum) growth, diet digestibility, and hepatic intermediary metabolism. A 154-day growth trial was performed with 252 rainbow trout (78.3 ± 6.24 g) randomly divided into twelve tanks and fed four experimental diets containing increasing levels of TM: 0% (TM0), 25% (TM25), 50% (TM50), and 100% (TM100) of fishmeal substitution, corresponding to TM dietary inclusion levels of 0%, 5%, 10%, and 20%, respectively. A digestibility trial was performed feeding 180 rainbow trout (94.6 ± 7.31 g) with the experimental diets used in the growth trial. The growth parameters were not affected by TM dietary inclusion. Regarding the evaluated apparent digestibility coefficients (ADC), only the ADC of crude protein was affected, showing the following trend: TM0 = TM25 > TM50 > TM100. The activities of key hepatic amino acid catabolic and lipogenic enzymes were not affected by the dietary composition. The results suggest that a partially defatted TM could totally replace fishmeal in commercial rainbow trout diets without negative effects on fish performance.

In Vitro Digestibility Measurement of Feedstuffs in Donkeys Using the DaisyII Incubator.

Successful studies on in vitro digestibility measurement of feedstuffs with fecal inoculum have been reported for horses, whereas data on donkeys are currently lacking. In this study, we evaluated the use of the DaisyII Incubator for in vitro digestibility measurement of feedstuffs using donkey feces as source of microbial inoculum. The method was tested using seven feedstuffs commonly used in donkey diets (alfalfa, bromegrass, ryegrass, and timothy hays; wheat bran and wheat straw; barley grains). Feces were obtained from four female donkeys, and incubations were carried out at 1-week intervals for four consecutive weeks. Two bags of each feedstuff were incubated in digestion vessels containing a buffer/feces solution (90:10). In vitro apparent dry matter digestibility (DMD), true dry matter digestibility (IVTD), and neutral detergent fiber digestibility (NDFD) were evaluated at four incubation times: 30, 48, 60, and 72 hours. All digestibility parameters significantly increased from 30 to 72 hours of incubation. At 72 hours of incubation, the within-laboratory repeatability and reproducibility of the method were 2.7% and 5.0% for DMD and 1.6% and 3.9% for IVTD, respectively. The method was less repeatable and reproducible for NDFD (4.5% and 10.4%, respectively).

Partially defatted black soldier fly larva meal inclusion in piglet diets: effects on the growth performance, nutrient digestibility, blood profile, gut morphology and histological features.

BACKGROUND: The aim of this trial was to investigate the effects of different inclusion levels of a partially defatted black soldier fly (BSF, Hermetia illucens L.) larva meal on the growth performance, nutrient digestibility, blood profile, gut morphology and histological features of piglets. A total of 48 newly weaned piglets were individually weighed (initial body weight (IBW): 6.1 ± 0.16 kg) and randomly allocated to 3 dietary treatments (4 boxes as replicates/treatment and 4 animals/box). BSF larva meal was included at increasing levels (0% [BSF0], 5% [BSF5] and 10% [BSF10]) in isonitrogenous and isoenergetic diets formulated for two feeding phases: I (from d 1 to d 23) and II (from d 24 to d 61). The weight gain (WG), average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) were calculated for each feeding phase and for the whole trial. The haematochemical parameters and nutrient digestibility of the piglets were also evaluated. A total of 3 piglets per box were slaughtered on d 61 and the slaughtered piglets were submitted to morphometric investigations and histopathological examinations. RESULTS: No overall significant differences were observed for growth performance (P > 0.05), except for the ADFI of phase II, which showed a linear response to increasing BSF meal levels (P < 0.05, maximum for the BSF10 group). Dietary BSF meal inclusion did not significantly influence the blood profile, except as far as monocytes and neutrophils are concerned, and these showed a linear and quadratic response, respectively, to increasing BSF meal levels (P < 0.05, maximum for the BSF10 and BSF5 groups, respectively). On the other hand, the nutrient digestibility, gut morphology and histological features were not affected by dietary BSF meal inclusion (P > 0.05). CONCLUSIONS: The obtained results show that a partially defatted BSF larva meal can be used as a feed ingredient in diets for weaned piglets without negatively affecting their growth performance, nutrient digestibility, blood profile, gut morphology or histological features.

Effect of rearing substrate on growth performance, waste reduction efficiency and chemical composition of black soldier fly (Hermetia illucens) larvae.

BACKGROUND: Wastes can be used as rearing substrate by black soldier fly (BSF) larvae, the latter being exploitable as a protein source in animal feed. This research aimed to assess the influence of four rearing substrates (Trial 1 (organic wastes): a mixture of vegetable and fruit (VEGFRU) vs. a mixture of fruits only (FRU); Trial 2 (agro-industrial by-products): brewery (BRE) vs. winery (WIN) by-products) on BSF larvae development, waste reduction efficiency and nutritional composition. RESULTS: If respectively compared to FRU and WIN, VEGFRU and BRE larvae needed less time to reach the prepupal stage (22.0, 22.2, 20.2 and 8.0 days of trial, respectively) and had higher protein content (229.7, 257.3, 312.9 and 395.7 g kg-1 dry matter). The waste reduction index ranged from 2.4 (WIN) to 5.3 g d-1 (BRE). BRE larvae showed the lowest saturated and the highest polyunsaturated fatty acid proportions (612.4 and 260.1 g kg-1 total fatty acids, respectively). CONCLUSION: Vegetable and fruit wastes and winery by-products can be used as rearing substrates for BSF larval mass production. Brewery by-products led to very promising larval performance and nutritional composition. However, given BRE limited availability, low BRE dietary inclusion levels could be used with the purpose of increasing larval performance. © 2018 Society of Chemical Industry.

Nutritional value of a partially defatted and a highly defatted black soldier fly larvae (Hermetia illucens L.) meal for broiler chickens: apparent nutrient digestibility, apparent metabolizable energy and apparent ileal amino acid digestibility.

BACKGROUND: The study aimed to determine the apparent total tract digestibility coefficients (ATTDC) of nutrients, the apparent metabolizable energy (AME and AMEn) and the amino acid (AA) apparent ileal digestibility coefficients (AIDC) of a partially defatted (BSFp) and a highly defatted (BSFh) black soldier fly larvae meal. The experimental diets were: a basal diet and two diets prepared by substituting 250 g/kg (w/w) of the basal diet with BSFp or BSFh, respectively. RESULTS: Significant differences were found between BSFp and BSFh meals for ATTDC of the nutrients: BSFp resulted more digestible than BSFh, except for ATTDC of CP which did not differed between meals, while a statistical trend was observed for ATTDC of DM and EE. The AME and AMEn values were significantly (P < 0.05) different between the two BSF meals, with higher levels for BSFp (16.25 and 14.87 MJ/kg DM, respectively). The AIDC of the AA in BSFp ranged from 0.44 to 0.92, while in BSFh they ranged from 0.45 to 0.99. No significant differences were observed for the AA digestibility (0.77 and 0.80 for BSFp and BSFh, respectively), except for glutamic acid, proline and serine that were more digestible in the BSFh meal (P < 0.05). CONCLUSIONS: Defatted BSF meals can be considered as an excellent source of AME and digestible AA for broilers with a better efficient nutrient digestion. These considerations suggested the effective utilization of defatted BSF larvae meal in poultry feed formulation.

Relationships between botanical and chemical composition of forages: a multivariate approach to grasslands in the Western Italian Alps.

BACKGROUND: Plant composition of species-rich mountain grasslands can affect the sensorial and chemical attributes of dairy and meat products, with implications for human health. A multivariate approach was used to analyse the complex relationships between vegetation characteristics (botanical composition and plant community variables) and chemical composition (proximate constituents and fatty acid profile) in mesophilic and dry vegetation ecological groups, comprising six different semi-natural grassland types in the Western Italian Alps. RESULTS: Mesophilic and dry grasslands were comparable in terms of phenology, biodiversity indices and proportion of botanical families. The content of total fatty acids and that of the most abundant fatty acids (alpha-linolenic, linoleic and palmitic acids) were mainly associated to nutrient-rich plant species, belonging to the mesophilic grassland ecological group. Mesophilic grasslands showed also higher values of crude protein, lower values of fibre content and they were related to higher pastoral values of vegetation compared to dry grasslands. The proximate composition and fatty acid profile appeared mainly single species dependent rather than botanical family dependent. CONCLUSION: These findings highlight that forage from mesophilic grasslands can provide higher nutritive value for ruminants and may be associated to ruminant-derived food products with a healthier fatty acid profile. © 2016 Society of Chemical Industry.