In vivo performances, ileal digestibility, and physicochemical characterization of raw and boiled eggs as affected by Tenebrio molitor larvae meal at low inclusion rate in laying quail (Coturnix japonica) diet

A total of 120, twelve wk old female Japanese quails were divided into 4 groups (6 replicates of 5 birds each). The control group (CON) fed a corn-soybean diet; in the other 3 groups, Tenebrio molitor larvae meal (TML) replaced 5, 10, and 20% of the soybean protein (T5, T10, and T20). The laying performance and egg quality were studied for 54 d. The data were processed by a one-way ANOVA; the orthogonal contrast analysis was performed to test the linear, quadratic and cubic effects among the means. The laying rate and egg mass linearly decreased (P < 0.01) as the TML inclusion level in the diet increased. The egg weight and feed conversion ratio linearly increased from the control to T20 diet (P < 0.01) while the digestibility of dry matter, organic matter, and crude protein linearly decreased (P < 0.05). The albumen and yolk weight showed a linear increase (P < 0.01) due to dietary TML inclusion, while the eggshell weight showed the opposite (P < 0.05). The estimated activity of Δ9-desaturase (C16:0), Δ5+Δ6-desaturase on both polyunsaturated fatty acid n-6 and n-3 linearly increased (P < 0.05) as affected by dietary TML. The boiled yolk lightness (L*) showed higher values in T5 and T10 groups (quadratic contrast, P < 0.01). The yolk redness index (a*) showed lower values in T5 and T20 than control and T10 groups (cubic contrast, P < 0.01). The albumen L*, a*, and b* indexes showed a significant effect of the quadratic contrast (P < 0.05). In addition, the albumen b* index showed a significant effect of the cubic contrast (P < 0.01). The total lipids showed the highest values (cubic contrast, P < 0.05) in the T10 and T20 groups. The total monounsaturated fatty acids linearly increased (P < 0.05) according to the increase of dietary TML. The best inclusion level of defatted TML meal for laying quails seems to be 1.4% of diet, corresponding to the T5 diet.

Influence of COVID-19 on the poultry production and environment

Although chickens are not susceptible to SARS-CoV-2, several coronavirus disease outbreaks have been described concerning poultry processing facilities in different countries. The COVID-19 pandemic and the developed strain caused 2nd, 3rd, and recent Indian strain waves of epidemics that have led to unexpected consequences, such as forced reductions in demands for some industries, transportation systems, employment, and businesses due to public confinement. Besides, poultry processing plants' conditions exacerbate the risks due to the proximity on the line, cold, and humidity. Most workers do not have access to paid sick time or adequate health care, and because of the low wages, they have limited reserves to enable them to leave steady employment. In addition, workers in meat and poultry slaughterhouses may be infected through respiratory droplets in the air and/or from touching dirty surfaces or objects such as workstations, break room tables, or tools. Egg prices have increased dramatically during the lockdown as consumers have started to change their behaviors and habits. The COVID pandemic might also substantially impact the international poultry trade over the next several months. This review will focus on the effect of COVID-19 on poultry production, environmental sustainability, and earth systems from different process points of view.

Chemistry of Tropical Eucheumatoids: Potential for Food and Feed Applications

The use of seaweeds as additives in animal nutrition may be a valid option to traditional feed as they represent a rich source of minerals, carbohydrates and antioxidants. The aim of this study was to analyze the chemical composition and in vitro antioxidant capacity of two tropical eucheumatoids, Kappaphycus alvarezii and Kappaphycus striatus, in Malaysian wild offshore waters. The chemical analysis was performed via inductively coupled plasma-optical emission spectroscopy for evaluating the concentration of toxic (Cd, Pb, Hg, As) and essential elements (Mn, Fe, Cu, Ni, Zn, Se); NMR spectroscopy was used for carrageenans investigation. Furthermore, the soluble and fat-soluble antioxidant capacities were determined by FRAP, DPPH and ABTS assays. The chemical analysis revealed a higher content of trace elements in K. alvarezii as compared to K. striatus, and both exhibited a high mineral content. No significant differences in metal concentrations were found between the two species. Both samples showed a mixture of prevailing κ- and t-carrageenans. Finally, the levels of soluble and fat-soluble antioxidants in K. alvarezii were significantly higher than in K. striatus. Our findings suggest that K. alvarezii could be used as a potential feed additive because of its favorable chemical and nutritional features.

Blood profile and productive performance after partial substitution of maize grain with ancient wheat lines by-products in organic laying hens' diet

The aim of this research was to evaluate the effects of the partial substitution of maize grain with local ancient wheats by-products in an organic laying hens farm on animal performance and blood profile, as well as on eggs quality. A total of 80 Hy-Line W-36 Single Comb White Leghorn, 18 weeks old hens were homogenously divided into two groups. The two groups (40 laying hens each, 8 replicates, 5 hens/replicate) were fed two isoprotein and isoenergetic diets: the Control group (C) was fed a standard, organic maize-soybean meal diet whereas in the Ancient Grains group (AG) part of the maize grain was replaced by a mix of ancient grains middling, consisting in 50:50 of Triticum aestivum var. spelta (spelt) and Triticum durum dicoccum L. (emmer wheat). The birds fed the maize based-diet (C) showed a higher (P < 0.01) egg weight and feed intake than the Ancient Grains (AG) group. By contrary, the feed conversion ratio was more favourable (P < 0.05) in hens fed the Ancient Grains diet. The eggs produced by the hens fed the Control diet showed higher length and width than the other group (P < 0.01). The shell thickness and strength were also higher in the Control group (P < 0.01 and P < 0.05, respectively). The experimental dietary treatment positively affected some blood parameters. The Control group showed higher levels of cholesterol and triglycerides (P < 0.05) as well as of alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) (P < 0.01). In addition, butyrate, which may have great implications for the regulation of the immune response, resulted significantly higher in the caecal content of hens from the Ancient Grains group. Overall, the Ancient Grains diet seemed to be able to guarantee the production performances with positive effects on the animal health.

Multiple Amino Acid Supplementations to Low-Protein Diets: Effect on Performance, Carcass Yield, Meat Quality and Nitrogen Excretion of Finishing Broilers under Hot Climate Conditions

The objective of this study was to evaluate the effect of low-protein diets with amino acid supplementation on growth performance, carcass yield, meat quality and nitrogen excretion of broilers raised under hot climate conditions during the finisher period. In trial 1, broilers from 28 to 49 days of age were fed 18% crude protein (CP) as a positive control or 15% CP supplemented with (1) DL-methionine (Met) + L-lysine (Lys), (2) Met + Lys + L-Arginine (Arg), or (3) Met + Lys + L-Valine (Val). In trial 2, broilers from 30 to 45 days of age, were fed an 18% CP diet as a positive control or 15% CP supplemented with Met, Lys, Arg, Val, L-Isoleucine (Ile) or combination with glycine (Gly) and/or urea as nitrogen sources: (1) Met + Lys, (2) Met + Lys + Arg, (3) Met + Lys + Val, (4) Met + Lys + Ile, (5) Met + Lys + Arg +Val + Ile + Gly, and (6) Met+ Lys + Arg + Val + Ile + Gly + urea. Protein use was improved by feeding low-protein amino acid-supplemented diets as compared to the high-protein diet. Feeding 15% crude protein diet supplemented with only methionine and lysine had no negative effects on carcass yield, CP, total lipids and moisture% of breast meat while decreasing nitrogen excretion by 21%.

Microbial and Fungal Phytases Can Affect Growth Performance, Nutrient Digestibility and Blood Profile of Broilers Fed Different Levels of Non-Phytic Phosphorous

Simple Summary

To reduce the environmental pollution is a must to preserve the health of the world. The environmental impact of poultry farming is receiving an increasing attention due to several emissions among these is phosphorus. This element is in general present in the commercial diets of broilers or laying hens in an amount exceeding the real needing of the animals, and, therefore, a great amount of phosphorus ends in the excreta. Thus, optimizing the amount of phosphorous in the diets of poultry could partially alleviate the environmental impact of these farms.

Abstract

A total of 420 day old chicks were divided into seven groups (5 replicates of 12 chicks/group) fed isoproteic and isoenergetic diets. The control group was fed diets containing 0.50%, 0.45% and 0.40% of non-phytic phosphorous (nPP) in starter (1–35), grower (37–56) and finisher (57–64 d) periods, respectively. The three intermediate nPP (IntnPP) groups were fed diets with 0.40%, 0.35% and 0.30% nPP according to the growth period and were submitted to three dietary treatments: unsupplemented; supplemented with 500 FTU/kg diet of an Aspergillus niger phytase (IntnPP_fp) and supplemented with 500 FTU/kg diet of an Escherichia coli phytase (IntnPP_bp). The three low nPP groups fed diets contained 0.30%, 0.25% and 0.20% nPP and were submitted to the same dietary treatments than IntnPP to obtain LnPP, LnPP_fp and LnPP_bp groups. IntnPP and LnPP groups had lower body weight gain and feed, crude protein (CP) and metabolizable energy (ME) intake (p < 0.05) than the control. Feed conversion ratio of IntnPP was more favorable (p < 0.01) than the LnPP group. CP and ME conversion ratios worsened (p < 0.01) in IntnPP and LnPP groups in comparison to the control. The nPP conversion ratio improved (p < 0.01) from the control to the LnPP group. Fungal phytase reduced (p < 0.05) feed, CP, ME and nPP intake than the bacterial one. IntnPP and LnPP diets had a lower digestibility of CP (p < 0.01) and CF (p = 0.01) than the control. IntnPP and LnPP groups showed a higher (p < 0.05) economic efficiency than the control. Blood total protein was the lowest (p < 0.05) in the LnPP group, the control group showed the lowest (p < 0.05) level of albumin and IntnPP group had the lowest (p < 0.01) globulin level. The use of bacterial phytase increased (p < 0.01) total protein and globulin and decreased (p < 0.05) the plasma cholesterol in comparison to fungal phytase. Decreasing nPP levels in colored slow-growing broilers diet negatively affects growth performance and the use of phytase can partly alleviate these negative effects, but the efficiency of different enzyme sources (bacterial or fungal) was tied to the dietary nPP levels.

The Inclusion of a Supercritical Fluid Extract, Obtained From Honey Bee Pollen, in the Diet of Gilthead Sea Bream (Sparus aurata), Improves Fish Immune Response by Enhancing Anti-oxidant, and Anti-bacterial Activities

In the present study, the immune-stimulatory effect of two levels of honey bee pollen (5 and 10%, P5 and P10 treatment, respectively) and its supercritical fluid extract (0. 5 and 1%, E0.5 and E1, respectively) included in the diet, was tested in gilthead seabream (Sparus aurata). The in vivo trial was preceded by the evaluation of antioxidant properties of three different bee pollen extracts obtained by water, ethanol 80%, and Supercritic Fluids Extraction (SFE). The preliminary evaluation attested that the SFE showed the lowest extraction yield (10.47%) compared to ethanol 80% (48.61%) and water (45.99%). SFE extract showed good antioxidant properties with high polyphenol content (13.06 mg GAE/g), radical scavenging activity (3.12 mg/ml), reducing power (38.68 mg/mL EC50). On the contrary, the water extract showed the significantly lowest polyphenol content (2 mg GAE/g; P < 0.05). The results of in vivo trial demonstrate that the diets supplemented with SFE bee pollen extract had a stimulatory effect on fish serum immunity, respect to the inclusion of raw pollen, this latter revealing some inhibitory effects in the immune response, such a decrease of serum peroxidase and lysozyme activities, particularly in P10 group significantly different (P < 0.05) from the control group. On the contrary, serum peroxidase, protease, antiprotease, were significantly increased in fish fed the diets supplemented with supercritical fluid extract, respect to the fish fed on control and on diets supplemented with 5 and 10% of raw pollen. For what concerns the bactericidal activity against Vibrio harveyii, all the treatments containing bee pollen regardless of the type showed their serum bactericidal activity significantly increased with respect to the control groups (p < 0.05). Given its high antioxidant properties, the absence of toxic solvents and the positive action carried out on improving the humoral response in gilthead seam bream, honey bee pollen SFE extract can be taken into account in the formulation of fish feeds.

Honey Bee Pollen in Meagre (Argyrosomus regius) Juvenile Diets: Effects on Growth, Diet Digestibility, Intestinal Traits, and Biochemical Markers Related to Health and Stress

This research aimed to evaluate the effects of the inclusion of honey bee pollen (HBP) in meagre (Argyrosoumus regius) juveniles' diets on growth performance, diet digestibility, intestinal morphology, and immunohistochemistry. Furthermore, stress-related molecular markers and biochemical blood profile of fish were evaluated, together with mineral trace and toxic element concentration in pollen and diets. Specimens of meagre (360) of 3.34 ± 0.14 g initial body weight, were randomly allocated to twelve 500 L circular tanks (30 fish per tank). Four diets were formulated: a control diet and three experimental diets with 1%, 2.5%, and 4% of HBP inclusion. All the growth parameters and crude protein and ether extract digestibility coefficients were negatively linearly affected by increased HBP inclusion (p < 0.0001). Histology of medium intestine showed slight signs of alterations in group HPB1 and HPB2.5 compared to control. Fish from HBP4 group showed severe alterations at the intestinal mucosa level. Immunohistochemical detection of TNF-α in the medium intestine showed the presence of TNF-α+ cells in the lamina propria, which resulted in accordance with the increased level of the TNF-α protein detected by immunoblotting in the liver. This stress situation was confirmed by the increased hepatic level of HSP70 (p < 0.05) in fish fed the HBP4 diet and by the linear decrease of total serum protein levels in HBP-containing diets (p < 0.0001). These negative effects can be related to the ultrastructure of the bee pollen grain walls, which make the bioactive substances unavailable and can irritate the intestine of a carnivorous fish such as meagre.

Quality of Eggs and Albumen Technological Properties as Affected by Hermetia Illucens Larvae Meal in Hens' Diet and Hen Age

Simple Summary

Concurrently with the actual challenges in the poultry industry, we aimed to assess the changes induced by the inclusion of an alternative protein source (partially defatted Hermetia illucens larva meal, HI) at two different levels as well as hen age on the overall egg quality and deepened their effect of albumen technological properties. This study could provide useful information for the egg supply chain in order to optimize egg utilization, as a whole or as egg products, thus preventing food losses or undesirable wastes. Specifically, based on the obtained results, the eggs laid by hens fed the highest inclusion of HI would be directed towards egg product industry due to their reduced eggshell percentage and thickness which could increase their fragility. Contrariwise, due to the impaired albumen technological properties, as foaming, found in the egg laid by 27–35 wk-old hens, they could be preferentially sold as a whole.

Abstract

The impact on the egg quality and the albumen technological properties were here evaluated as affected by diet and hen age (A) of 162 Hy-line Brown hens. Three isoproteic and isoenergetic diets were formulated respecting the requirements for Hy-line hens: the control diet (C) based on conventional protein sources, and other two where vegetable proteins were substituted at 25% (HI25) and 50% (HI50) by partially defatted Hermetia illucens larva meal (HI). Ten eggs collected from each group at the hen ages of 20, 27, and 35 weeks were evaluated. The eggshell percentage and thickness were significantly reduced in the HI50 eggs (11.93% and 476 µm, respectively) compared to the C (12.34%, 542 µm) and HI25 (12.54%, 516 µm). The aging lowered (p = 0.05) the protein and increased (p < 0.001) water contents of the eggs. Although the foam capacity of the HI50 albumen was halved than the C group (p < 0.05), it was unaffected by the aging. Additionally, this did not impair the volume and the textural properties of a batter (angel cake) in which it was included. On the opposite, the textural characteristics of the cake made by the oldest hens (i.e., 35 wk-old) were compromised. In conclusion, the diet and hen age differently affected egg quality and its technological properties, which could be positive to obtain eggs to destine directly to the market or to the egg industry.

Mirrors Can Affect Growth Rate, Blood Profile, Carcass and Meat Traits and Caecal Microbial Activity of Rabbits Reared in a "Small Group" Free-Range System

Simple Summary

The rabbit farming sector is going through a difficult period. The reduction in the consumption of rabbit meat and the increased attention paid by consumers to the welfare of farmed animals require the adoption of farming methods that are as “natural” as possible and at the same time may ensure the maintenance of good growth performance. In this sense, free-range breeding on the ground and in colonies allows the rabbits to express more natural behaviour, but it also presents some negative aspects such as decreased growth performance, higher energy expenditure of subjects due to a higher locomotion activity, and the need for a larger rearing space. Mirrors can represent a valid solution by improving the rabbits welfare and at the same time ensuring good growth performance and carcass quality traits.

Abstract

The aim of this work was to propose a model of free-range raising for rabbit able to maximize the animal welfare and at the same time the productive performances through the use of mirrors. A total of 81 rabbits were allocated into free-range areas and divided into three groups (nine replicates per group): in the first group (face to face, F2F), the rabbits of each replicate could see each other. In the second group (blind) each replicate was isolated from the others; in the third group (mirrors), the replicates were divided as for the Blind group but two mirrors were placed in a corner of the perimeter. The blind group rabbits showed the lowest final weight (p < 0.05), while rabbits from the mirrors groups showed the best FCR and net dressing out values. The blind group showed the highest production of total short chain fatty acids, acetate (p < 0.05) and propionate (p < 0.01). The F2F rabbits showed higher levels of creatine phosphokinase and lactate dehydrogenase and lower values of blood glucose than those of the other groups, due to the higher locomotion activity. The use of mirrors can improve rabbit’s growth performance and carcass traits by lowering the rabbit’s locomotion activity in comparison to the other tested systems.

Evaluation of the carryover effect of antibiotic, bee pollen and propolis on growth performance, carcass traits and splenic and hepatic histology of growing rabbits

Sixty-four nulliparous female rabbits were distributed among eight groups (eight animals/group). Group one was the unsupplemented control group; the other seven groups were supplemented with zinc bacitracin (ZnB) at 100 mg, or bee pollen (BP) and/or propolis (Pro) at 150 and 300 mg in a capsulated form, three times a week, day after day, continuously all over the experimental period. The experiment was run for eight parties; at each parity, 28 kids of each doe group (a total of 224 rabbits) were divided into two subgroups weaned, respectively, at 24 and 30 days of age. Thus, for each parity, there were 16 groups (eight does treatments × two weaning age, 14 rabbits per group). The growing rabbits fed the standard diets without supplements. The growth performance, the carcass traits, the liver and the spleen histology of rabbits were checked up to 90 days of age to find possible carryover effects of the supplements. The supplements had no significant effect on most of the growth performance at 90 days of age, but BP150 and BP+Pro300 increased the growth rate in comparison with ZnB group. The liver weight in the control, BP300 and Pro300 groups was higher than the ZnB one. The spleen weight was higher in the groups ZnB, BP150, Pro300 and BP+Pro300, followed by the control, BP300 and BP+Pro150 and thus Pro150. The heart % in the BP150 and Pro300 groups was higher than ZnB and BP+Pro150 groups. A lymphoid hyperplasia of splenic white pulp was observed in the BP+Pro groups, while propolis alone showed a mild activation of lymphobiosis. The Pro and BP groups showed the same picture of the control group exhibiting a hydropic degeneration of mostly hepatic cells, while the ZnB group exhibited adverse effect on the bile ducts featuring portal periductal inflammatory cells infiltration with epithelial hyperplasia reflecting chronic cholangitis.

Bee pollen and propolis as dietary supplements for rabbit: Effect on reproductive performance of does and on immunological response of does and their offspring

To evaluate the effect of bee pollen (BP) and/or propolis (Pro) supplementation on rabbit does, 64 nulliparous NZW rabbits does were distributed among eight groups (eight animals/group). One unsupplemented group was the control; the other seven groups were supplemented, respectively, with zinc bacitracin (ZnB) at 100 mg, BP at 150 and 300 mg, Pro at 150 and 300 mg, BP+Pro at 150 and 300 mg of each three times/week, day after day continuously along eight parities. The BP300, Pro300 and BP+Pro150 groups had higher body weight of litter at birth and number of kids born alive. The BP supplementation at 150 mg increased plasma total protein and albumin than the control group. The BP or Pro at 150 mg decreased plasma T₃ than the other groups except for BP+Pro150. The ZnB group had significantly greater T₃ /T₄ ratio compared to BP, Pro and BP+Pro at 150 mg. The BP+Pro150 group had less ALT than the control; BP300 and Pro 300 mg resulted in lower plasma AST than the groups Pro150 with or without BP and the control group. The plasma alkaline phosphatase of BP at 150 or 300 mg and BP+Pro150 was significantly greater than that of the Pro150 group. The BP+Pro300 group had higher WBCs than the other groups. In contrast, the lymphocytes were greater in the Pro and BP+Pro300 groups than in BP, Pro and BP+Pro at 150 mg. The groups supplemented with BP and BP+Pro at 150 and 300 mg had significantly greater SRBCs of doe rabbits and their offspring compared to the control and the ZnB group. The BP at 300 mg increased the serum albumin and α₁ -globulin than the control group. The Pro300 group had greater serum α₂ -globulin and β-globulin than the control group. The total globulin was significantly greater for the 300 mg propolis-supplemented groups than the control.

Laying performance, blood profiles, nutrient digestibility and inner organs traits of hens fed an insect meal from Hermetia illucens larvae

Given probable the increment in the nutritional needs of both humans and animals, animal production will have increased dramatically by 2050. Insect meals could be an alternative protein source for livestock, and they would also be able to reduce the environmental problems related to intensive animal production system. The aim of this study was to evaluate productive performance, blood analysis, nutrient digestibility, and changes in the internal organs of laying hens fed Hermetia illucens larvae meal (HI) at two different levels in substitution (25 or 50%) of soybean meal (SBM). A total of 162 Hy-line Brown hens (sixteen weeks old) were equally divided into three experimental groups and fed isoprotein and isoenergetic diets. Egg weight, feed intake, and feed conversion rate were not affected by the soybean meal substitution at both inclusion levels of insect meal. Egg mass was positively affected by the insect meal diets, as was the lay percentage, although only at the lowest inclusion level. Dry matter, organic matter, and crude protein digestibility coefficients were lower for the HI50 diet, probably due to the negative effect of chitin. A reduction in serum cholesterol and triglycerides was observed in both insect-meal fed groups, while serum globulin level increased only at the highest level of insect meal inclusion, and, consequently, the albumin to globulin ratio decreased. Overall, a protein replacement of 25% with an insect meal from Hermetia illucens larvae in the diet of laying hens seems to be more suitable and closer to the optimal level.

Productive performance and blood profiles of laying hens fed Hermetia illucens larvae meal as total replacement of soybean meal from 24 to 45 weeks of age

The aim of the research was to study the effects of an insect meal from Hermetia illucens larvae (HILM) as complete replacement of soybean meal (SBM) on productive performance and blood profiles of laying hens, from 24 to 45 wk of age. A total of 108 24-week-old Lohmann Brown Classic laying hens was equally divided into 2 groups (54 hens/group, 9 replicates of 6 hens/group). From 24 to 45 wk of age, the groups were fed 2 different isoproteic and isoenergetic diets: the control group (SBM) was fed a corn-soybean meal based diet, while in the HILM group the soybean meal was completely replaced by Hermetia illucens larvae meal. Feed intake, number of eggs produced, and egg weight were recorded weekly along the trial. At 45 wk of age, blood samples were collected from 2 hens per replicate. The use of HIML led to a more favorable (P < 0.01) feed conversion ratio in hens but lay percentage, feed intake, average egg weight, and egg mass were higher (P < 0.01) in hens fed the SBM diet. Hens fed insect meal produced a higher percentage of eggs from small (S), medium (M), and extra-large (XL) classes (P < 0.01) than SBM, while the SBM group had a higher percentage of eggs from the large (L) class (P < 0.01). The levels of globulin and albumin to globulin ratio were, respectively, higher and lower (P < 0.05) in HILM than the SBM group. Cholesterol and triglycerides were higher (P < 0.05 and P < 0.01, respectively) in hens from SBM than in the HILM group. Blood levels of Ca were higher (P < 0.01) in hens fed insect meal, while creatinine was higher (P < 0.01) in blood of hens fed SBM. Hermetia illucens larvae meal can be a suitable alternative protein source for laying hens even if the complete replacement of soybean meal needs further investigation to avoid the negative effects on feed intake.

Barbary partridge meat quality as affected by Hermetia illucens and Tenebrio molitor larva meals in feeds

A partial substitution (25 or 50%) of dietary protein with Tenebrio molitor (TM) and Hermetia illucens (HI) meals as protein sources in the diet of Barbary partridge (Alectoris barbara) has been tested in terms of raw and cooked meat quality. Twelve partridges per feeding group (control - SBM, HI25, HI50, TM25 and TM50) were slaughtered. The peeled carcasses of the HI25, HI50, TM25 and TM50 groups were heavier than those of the SBM group, both raw and cooked. The pH, color and shear force of the raw meat were not affected to any greater extent by the diet, whereas the presence of insect meal seemed to increase the yellowness index of the cooked meat. The proximate composition was unaffected by both the species and the level of insect meal, although the fatty acid profile was changed considerably. The HI and TM groups had significantly higher C18:1n-9 and lower C16:0 contents than SBM. Furthermore, Hermetia illucens, added as 50% of the dietary protein, induced a significant increase in C12:0 and C16:1n-7. As a result, the highest AI and TI were obtained for the HI50 diet (0.38 and 0.75, respectively), whereas the TM groups both had intermediate AI values (around 0.35) and the lowest TI (0.67). Finally, the cholesterol content of the birds was not affected by insect inclusion in the feeds.

Evaluation of an insect meal of the Black Soldier Fly (Hermetia illucens) as soybean substitute: Intestinal morphometry, enzymatic and microbial activity in laying hens

This research investigated the ileum morphometry and enzymatic activity, the caecal volatile fatty acid production and the apparent nutrient digestibility in laying hens fed a Hermetia illucens larvae meal (HILM) as a complete replacement of diet soybean meal (SBM). The hens fed HILM exhibited a lower live weight (P<0.05) and a higher incidence of the full digestive tract (P<0.05) than the SBM group. In the duodenum, the maltase exhibited a higher (P<0.05) activity in the HILM group while the intestinal alkaline phosphatase (IAP) had a higher (P<0.05) activity in the SBM group. In the ileum, the maltase and saccarase had a higher activity in the HILM hens (P≤0.01) while the IAP and ɤ glutamil transferase had a higher activity in the SBM group (P<0.05 and P<0.01, respectively). The HILM group showed a higher (P<0.05) villi height in the duodenum, while the opposite happened in the jejunum and the ileum. Only in the ileum the crypt depth resulted higher (P<0.05) in the HIML group than in the SBM. The higher production of acetate (P<0.05) and butyrate (P<0.01) affected the total production of volatile fatty acids of the HILM group. The coefficient of apparent digestibility of dry and organic matter as well as of crude protein was higher (P<0.05) in SBM group. The total replacement of SBM with HILM in laying hens diet from 24 to 45weeks of age resulted in a higher caecal production of butyric acid while the enzymatic activities of brush border membrane were partially reduced.

Growth performance, blood profiles and carcass traits of Barbary partridge (Alectoris barbara) fed two different insect larvae meals (Tenebrio molitor and Hermetia illucens)

To investigate the effect of two insect meals (from Hermetia illucens, HI and Tenebrio molitor, TM larvae) on productive performance and blood profiles of Barbary partridge, ninety, seven days old partridges were divided into 5 groups (6 replicates, 3 partridges/replicate). Up to 64d, the groups fed 5 isoproteic and isoenergetic diets: the control fed a corn-soybean meal diet (SBM group); in TM25 and TM50 groups the 25 and 50% of SBM proteins were substituted by the protein from TM, respectively; in HI25 and HI50 groups the 25 and 50% of SBM were substituted by the protein from HI, respectively. The birds fed TM25 and both the HI levels reached a higher (P<0.01) live weight at 64d than the control. Considering the entire experimental period the TM groups had a more favorable FCR than SBM. The carcass weights of all the insect groups were higher (P<0.01) than the control. The weight of the full digestive tract in SBM group was the highest (P<0.01). The caecal weight, the intestinal and caecal length were the highest (P<0.01) in the SBM group. The SBM group the highest value of albumin/globulin (P<0.01) and creatinine (P<0.05). TM seems to be more effective than HI in improving FCR. The reduced albumin/globulin ratio in the insect meal fed groups could be ascribed to the chitin content and this result was not affected by the amount of chitin intake, suggesting that also the lowest values are able to express their potential effects in partridges.

Insect-based diet, a promising nutritional source, modulates gut microbiota composition and SCFAs production in laying hens

Insects could be potential nutritional sources both for humans and animals. Among these, Hermetia illucens, with good amount of chitin and proteins, represents a suitable diet replacement for laying hens. Little is known about insect diet effects on the microbial ecology of the gastrointestinal tract and bacterial metabolites production. In this study we investigated the effect of H. illucens larvae meal administration on cecal microbiota and short chain fatty acids (SCFAs) production in laying hens. 16S rDNA sequencing showed strong differences between cecal microbiota of soybean (SD) and insect diet (ID) groups both in type and relative abundance (unweighted and weighted beta diversity) of microbial species. In particular, Bacteroides plebeius, Elusimicrobium minutum, Alkaliphilus transvaalensis, Christensenella minuta, Vallitalea guaymasensis and Flavonifractor plautii represented the principal contributors of changes in gut microbiota composition of ID group (FDR p-values < 0.05). Of these, F. plautii, C. minuta and A. transvaalensis have the potential to degrade the chitin’s insect meal and correlated with the observed high levels of gut SCFAs produced in ID group. These microorganisms may thus connect the chitin degradation with high SCFAs production. Our results suggest H. illucens as a potential prebiotic by well feeding gut microbiota.

Semen quality, antioxidant status and reproductive performance of rabbits bucks fed milk thistle seeds and rosemary leaves

The study aimed to investigate the effects of milk thistle seeds (MTS) and rosemary leaves (RL) both at 5 and 10g/kg diet on reproductive performance, semen quality and blood metabolites of rabbit bucks. A total of 35 rabbit bucks were randomly distributed into five experimental groups (7 bucks/group). All the groups were fed the same basal diet. The 1st group (control) did not have MTS and RL in its basal diet. The 2nd and 3rd groups were supplemented with MTS at 5 and 10g/kg, respectively. The 4th and 5th groups were fed the basal diet supplemented with RL at 5 and 10g/kg, respectively. The sperm concentration (SC), total sperm output (TSO), live sperm (LS), total live sperm (TLS) and total motile sperm (TMS) were significantly greater in the bucks fed MTS at 10 and RL at 5g/kg diet than the control group. Bucks fed MTS at 10g/kg diet had higher fertility than the control. Also, RL 5g/kg group showed higher testosterone and fertility than the control, but the MTS 10g/kg group showed the highest value for both parameters. In conclusion, MTS and RL at 10 and 5g/kg, respectively, significantly improved the semen quality and the fertility and MTS also increased the economic efficiency of rabbit bucks.