Laura Gasco

Effects of a Natural Extract of Chestnut Wood on Digestibility, Performance Traits, and Nitrogen Balance of Broiler Chicks

Currently, feed ingredients containing tannin are attracting more interest as substitutes for antibiotic growth promoters in animal and poultry feeding. This study investigated the influence of a natural extract of chestnut wood (Silvafeed ENC) on broiler digestibility (experiment 1) and on the growth performance, carcass quality, and nitrogen balance of broilers (experiment 2). Results showed that the inclusion of ENC did not influence the apparent digestibility of organic matter, CP, and ether extract. Chick growth performance showed a quadratic or cubic response with increasing levels of ENC. When chicks were fed ENC from 14 to 56 d of age, the ENC had a positive effect on average daily gain in the first 2 wk of addition, whereas this effect was not evident in the last 2 wk compared with the control group. Similar trends were also shown for daily feed intake. Overall, the chicks fed 0.20% ENC had significantly better growth performance than the control group. Carcass analysis showed no gross lesions in organs and no significant differences in thigh and breast composition among groups. Noteworthy is the fact that the ENC-treated groups had less total litter nitrogen; in particular, chicks fed 0.15 and 0.20% ENC showed a significant difference in total litter nitrogen compared with the control group. No significant difference in nitrogen balance was observed. Addition of 0.20% ENC seemed to have a positive influence on chick feeding.

Yellow mealworm larvae (Tenebrio molitor, L.) as a possible alternative to soybean meal in broiler diets

Abstract The aim of the study was to evaluate the feasibility of replacing soybean meal (SBM) with Tenebrio molitor larvae (TML) meal in broiler diets. A total of 80 30-d-old male Shaver brown broilers were divided into two groups fed on two isoproteic and isoenergetic diets differing for protein source (SBM vs. TML). Up to 62 d of age, body weight and feed intake were recorded weekly and body weight gain, feed conversion ratio (FCR), protein efficiency ratio (PER) and European efficiency factor (EEF) were calculated. At 62 d, blood samples were collected from 16 birds/group for evaluation of blood profiles. Feed intake was not different between groups considering the entire period of the trial. The FCR was more favourable in the TML than SBM group from 46 d of age and in the entire period of the trial (4.13 vs. 3.62). The PER was higher in the SBM than in the TML group (1.92 vs. 1.37) while the EEF was higher in broilers fed on the TML diet (132.6 vs. 156.2). Albumin-to-globulin ratio was higher in broilers fed on SBM than in the other group (0.44 vs. 0.30). aspartate aminotransferase and alanine aminotransferase were higher in TML than SBM (195.1 vs. 178.6 U/l and 82.07 vs. 46.71 U/l, respectively). Uric acid was higher in broilers fed on SBM than TML (5.40 vs. 4.16 mg/dl). TML did not affect feed intake and growth rate of broilers from 30 to 62 d of age when compared to an isoproteic and isoenergetic SBM diet, but FCR of the TML group was more favourable than that of the SBM group. The lowest albumin-to-globulin ratio in broilers fed on TML suggests a higher immune response, probably due to the prebiotic effects of chitin.

The use of ozone in trout hatchery to reduce saprolegniasis incidence.

At present, the prophylactic measures in trout hatchery are based on the use of formaldehyde. The purpose of this work is to set up an alternative system of prevention of saprolegniasis, using ozone. The experiment was carried out in two successive cycles. The first experiment lasted 46 days and five different treatments were applied on every second day on the same number of lots of 250 eggs each, of which three were treated with ozone (O3) in concentrations of 0.01, 0.03 and 0.2 ppm (10 min), one reference treatment with formaldehyde (1–2 ml/l, 15 min) and one as control, without any disinfectants. The second experiment, which lasted 60 days, consisted also of five levels of treatment on the same number of lots of 100 eggs each, to which 0.01 ppm O3 (10 min) was applied on every second day, while 0.01, 0.1 and 0.3 ppm O3 (10 min) were applied daily. The formaldehyde treatment was performed in the same way as the experiment 1 (exp. 1). From the results, it has emerged that the treatment with ozone is effective and the hatching eggs range from 42.6% to 49.1% dose of ozone from 0.01 to 0.2 ppm. As observed in experiment 2 (exp. 2), the dose of 0.3 ppm applied every second day seems to be over the threshold of toxicity.

Effects of chestnut tannins on carcass characteristics, meat quality, lipid oxidation and fatty acid composition of rabbits.

Seventy two male Bianca Italiana rabbits were used to study the effects of the inclusion (0%, 0.5%, and 1.0%) of a natural extract of chestnut wood (Silvafeed ENC) in the diet on productive traits, carcass characteristics, meat quality, lipid oxidation and fatty acid composition of rabbit meat. Results showed ENC had no significant effect on live weight, productive traits, hot carcass weight, dressing percentage, skin weight, pH, cooking losses, shear force and colour. The iron content was higher in Longissimus thoracis et lumborum (LTL) muscle of rabbit fed the ENC 1.0% diet than the control group. TBARS average values in the group ENC 0.5% were significantly lower (P<0.05) than in the control and ENC 1.0% groups. Myristic acid (C14:0; P<0.01), palmitoleic acid (C16:1 cis-9; P<0.05) and pentadecanoic acid (C15:0; P<0.01) contents were lower in LTL muscle of rabbits fed the ENC 1.0% diet, whereas the palmitic acid (C16:0) content was higher (P<0.05) in the rabbits of this group. Moreover, the rabbits fed with the ENC 0.5% diet had lower (P<0.01) levels of trans-vaccenic acid (C18:1 trans-11) compared to rabbits fed with the control diet. No significant differences were observed in saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) fatty acids, as well as in PUFA/SFA and n-6/n-3 ratios among the groups.

Use of Tenebrio molitor larvae meal as protein source in broiler diet: Effect on growth performance, nutrient digestibility, and carcass and meat traits

The aim of this research was to study the effect of insect meal from larvae ( larvae meal [TML]) as complete replacement of soybean meal (SBM) on growth performance, nutrient digestibility, and carcass and meat traits of broilers. A total of eighty 30-d-old male Shaver brown broilers were homogenously divided into 2 groups (each consisting of 8 replicates of 5 birds). Up to 62 d of age, the groups were fed 2 isoproteic and isoenergetic diets differing for the ingredient used as the main protein source: the control group was fed a corn-SBM-based diet, whereas in the TML group, the SBM was completely replaced by TML. Broiler growth performance was measured during the trial. At 62 d of age, 2 broilers per replicate (16 per group) were slaughtered and apparent ileal digestibility coefficients and carcass and meat traits were determined. The use of TML as the main protein source in the broiler diet had no significant effect on most growth performance and carcass traits and chemical and physical properties of meat, the latter being important for marketing purposes. The feed conversion ratio in the entire experimental period (from 30 to 62 d) was improved in the TML group compared with the SBM group ( < 0.05). The apparent ileal digestibility coefficients of DM, OM, and CP in broilers fed the SBM diet were greater ( < 0.01) than the other group. The full digestive system in broilers fed SBM had a lower ( < 0.05) absolute and relative weight than that of broilers fed TML. Also, the weight and the percentage of the spleen in the SBM group were lower ( < 0.05) than those in the TML group. The length of the entire intestine in the group fed TML was greater ( < 0.05) than the other group and the same happened when intestinal length was expressed as percentage of broiler BW ( < 0.05). Among the different intestinal tracts, the ileum and ceca of broilers fed TML had a greater ( < 0.05) length than that of broilers fed SBM. Also, ceca weight (as an absolute value or percentage on live weight) in broilers fed TML was greater ( < 0.05) than that of broilers fed SBM. Breast pH and cooking losses in broilers fed TML were greater ( < 0.05) than those of broilers fed SBM. Chemical characteristic of meat obtained from right breast of slaughtered broilers were unaffected by dietary treatments. larvae meal can be a suitable alternative protein source for growing broilers and also when used as principal protein contributor to the diet.

Tenebrio Molitor Meal in Rainbow Trout (Oncorhynchus Mykiss) Diets: Effects on Animal Performance, Nutrient Digestibility and Chemical Composition of Fillets

This study evaluated the effects of diets containing Tenebrio molitor (TM) larvae meal on growth performances, somatic indexes, nutrient digestibility, dorsal muscle proximate and fatty acid (FA) compositions of rainbow trout. Three hundred sixty fish were randomly divided into three groups with four replicates each. The groups were fed diets differing in TM inclusion: 0% (TM0), 25% (TM25) and 50% (TM50) as fed weight basis. Weight gain was not affected by treatment. Feeding rate was significantly higher in TM0 than TM50. Feed conversion ratio was significantly higher in TM0 than TM25 and TM50, while an opposite trend was observed for protein efficiency ratio and specific growth rate. The survival rate was significantly lower in TM0 than TM25 and TM50. The apparent digestibility of protein was significantly lower in the TM50 group than the other groups, while the apparent digestibility of dry matter, organic matter and lipids was unaffected by treatment. If compared to control, the protein and lipid contents of fillets were respectively increased and decreased following TM inclusion in the diet. The Σn3/Σn6 FA ratio of fish dorsal muscle was linearly (TM0>TM25>TM50) reduced by TM inclusion in the diet. Results suggested that TM could be used during the growing phase in trout farming; however, additional studies on specific feeding strategies and diet formulations are needed to limit its negative effects on the lipid fraction of fillets.

Partial or total replacement of soybean oil by black soldier fly larvae (Hermetia illucens L.) fat in broiler diets: effect on growth performances, feed-choice, blood traits, carcass characteristics and meat quality

Abstract The present research studied for the first time the potential application of the fat derived from the black soldier fly larvae fat (BSLF) in substitution to the soybean oil in the diet for broiler chickens: growth performances, feed-choice, blood traits, carcass characteristics and meat quality were considered in this study. A total of 150 male broiler chicks (Ross 308) at one-day of age were randomly allotted to 3 dietary treatments (5 replicates and 10 birds/pen): a basal control diet (C group), and the same diet in which the soybean oil was replaced by 50% (CH group) or 100% (H group) BSLF. Growth performances, feed-choice test, blood traits and slaughtering performances were not influenced by diets. Independently of BSLF inclusion, broiler chickens breast meat had also similar crude protein and ether extract contents and displayed similar thawing loss. Furthermore, pH, L*, a*, b* colour values, and drip loss were unaffected by dietary treatments both at 0 and 9 days of refrigerated storage. As expected, the fatty acid profile of broiler chickens breast was greatly affected by BSLF inclusion level. With increasing BSLF inclusion rate, the proportion of SFA increased (32.2, 37.8, 43.5% for C, CH and H breast meat, respectively, p < .001) to the detriment of the PUFA fraction (22.7, 23.0, 22.9% for C, CH and H breast meat, respectively, p < .001). On the contrary, MUFA fraction was unaffected. BSLF inclusion guaranteed satisfactory productive performances, carcass traits and overall meat quality, thus suggesting that BSLF could be a promising new feed ingredient for chickens.

Growth performance of common catfish (Ameiurus melas Raf.) fingerlings fed mealworm (Tenebrio molitor) diet

A pre-fattening trial was performed to evaluate the effect of replacement of fishmeal (FM) with insect meal (IM; Tenebrio molitor) on growth performance and survival rate of common catfish (Ameiurus melas). Fingerlings of A. melas (mean body weight 0.248±0.07 g) were randomly distributed over 4 indoor tanks of 2 m3 at a density of 2,000 fish/tank, and kept at a temperature of 23-25 °C in two separated recirculating aquaculture systems. Fish were divided into two groups (two tanks per group): FM and IM. Fish of the FM group were fed with a control diet (51.6% protein and 18.1% lipid), whereas those of the IM group received a diet (50.8% protein and 22.1% lipid) in which 50% of FM was substituted with IM. Chemical parameters (moisture, crude protein, total lipids, ether extract, and ash) and fatty acid profile of the two feeds is reported. The feeding trial lasted 90 days and fish were weighed at the beginning of the trial and then on monthly basis. Growth performance was good in both groups. However, fish ...

Antioxidant responses and renal crystal formation in rainbow trout treated with melamine administered individually or in combination with cyanuric acid.

In 2007 and 2008, renal stone formation and kidney damage in human infants were linked to consumption of melamine (MEL)-contaminated infant formula, as well as renal failure and death in pets due to pet food containing both MEL and cyanuric acid (CYA). The aim of this study was to examine the effects of MEL and CYA administered individually or in combination on concentrations of certain metabolites and enzyme activities that serve as markers for oxidative stress in kidney and liver of rainbow trout. In addition, the levels of muscle MEL and renal crystal formation were determined. Trout were fed MEL and/or CYA for 8 wk at 250, 500, or 1000 mg of each compound/kg in feed. Fish muscle residues of MEL exhibited a dose-response relationship. Coexposure of trout to MEL and CYA at the highest dose led to lower MEL residue concentrations in muscle compared to exposure to MEL alone. Renal MEL–CYA complexes were found in kidneys of fish treated with combined MEL and CYA. A dose response was evident with respect to both (1) number of trout displaying renal crystals and (2) number of crystals per fish. Changes in concentration of antioxidant parameters, such as glutathione, superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase, were recorded in both tissues of MEL- and CYA-dosed trout. Lipid peroxidation was more pronounced in kidney than liver. Therefore, feed contaminated with both MEL and CYA could be problematic for fish, as MEL administered to trout, individually or in combination with CYA, may facilitate the onset of oxidative damage in trout.

Antioxidant response versus selenium accumulation in the liver and kidney of the Siberian sturgeon (Acipenser baeri).

The aim of this study was to examine the effects of selenium on concentrations of metabolites and enzyme activities acting as antioxidant markers in liver and kidney of Siberian sturgeon Acipenser baeri. Sturgeons were fed selenium cysteine for 30 and 60 d at 1.25, 5, 20mg Sekg(-1). Selenium level in the control feed was 0.32 mg kg(-1). Se concentration was measured in liver, kidney and muscle of every specimen. Sturgeon accumulated Se in tissues with a clear dose-response relationship and the highest Se concentration was recorded in liver. This outcome is lined up with the findings obtained on the antioxidant markers evaluated in both tissues, and in which a dose-response for several biomarkers was recorded in liver. The superoxide dismutase activity in Se-treated fish was generally induced, while catalase activity was lower in liver or unaltered in kidney. The concentrations of glutathione S-transferase, glutathione reductase and total glutathione responded differently for both tissues and were induced in a different way at both endpoints. No changes of glyoxalase I activity were noted for both Se-treated tissues, while for glyoxalase II enzyme in liver a dose-related pattern was found showing a reversible effect (decreased and increased counteractive response) only in the 5 mg kg(-1) group. Moreover, the highest Se concentrations did not cause marked changes in malondialdehyde levels of liver and kidney. The enhancement of glutathione peroxidase activity in Se-treated sturgeon might have prevented the lipid peroxidation in both tissues, providing to the Siberian sturgeon a great defense ability versus the prooxidant effect of selenium.