Ivo Zoccarato

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.

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.

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.

Active components of common traditional Chinese medicine decoctions have antioxidant functions.

Many traditional Chinese medicine (TCM) decoctions are proven to have multiple functions in animal production. These decoctions are seldom recognized by the international scientific community because the mechanisms of action are not clearly elucidated. According to TCM theory, Cortex Phellodendri (COP), Rhizoma Atractylodes (RA), Agastache Rugosa (AR), and Gypsum Fibrosum (GF) can be used to formulate a medicinal compound that prevents or cures animal disease caused by heat stress. The aim of this research was to study the regulatory functions of the active components of TCM and to elucidate the effects of different TCM decoctions on antioxidant activity and lipid peroxide content, using in vitro and in vivo models of heat stress. For in vitro experiments, intestinal crypt-like epithelial cell line-6 (IEC-6) cells were employed to evaluate the effects of the active components of COP, RA, AR, and GF. For in vivo experiments, forty-eight 2-mo-old Chinese experimental mini-pigs (7.20 ± 0.02 kg) were randomly assigned to 4 groups: a normal-temperature group (NTG); a high-temperature group (HTG); HTG treated with COP, RA, AR, and GF (1:1:1:1, TCM1); and HTG treated with COP, RA, AR, and GF (1:1:1:0.5, TCM2). Results showed that the active components of the COP, RA, AR, and GF increased (P < 0.05) the proliferation and viability of heat-stressed IEC-6 cells and that the most effective treatment doses of COP alkaloid, RA Aetherolea, Herba Agastachis Aetherolea, and GF water extract were 200, 100, 100, and 200 µg/mL, respectively. All 4 active components increased (P < 0.05) superoxide dismutase, glutathione peroxidase activities, and glutathione content, and decreased (P < 0.05) malondialdehyde content with respect to the heat-stressed group to concentrations similar to those seen in NTG. In vivo experiments demonstrated that TCM1 and TCM2 improved (P < 0.05) the poor growth performance seen in HTG pigs. The superoxide dismutase, glutathione peroxidase activities, and malondialdehyde content in porcine jejunum treated with TCM1 and TCM2 were not different (P > 0.05) from those seen in the NTG and were better (P < 0.05) than results seen in the HTG. Overall, it appeared that TCM2 was more effective than TCM1 in ameliorating the effects of heat stress in pigs. In conclusion, this study revealed that the active components of common TCM decoctions have antioxidant functions.

Dietary Supplementation of Oregano and Sage Dried Leaves on Performances and Meat Quality of Rabbits

The aim of this research was to evaluate the dietary supplementation 1% (w/w) of oregano and sage dried leaves on performances and meat quality of broiler rabbits. A feeding trial, which lasted 48 d, was carried out on 105 male Bianca Italiana rabbits randomly divided in seven groups and fed ad libitum. At the end of the trial ten animals per group were slaughtered and samples of dorsal muscle were taken in order to perform laboratory analysis. Mortality rate did not statistically differ between groups. Growth performances of animals fed diets supplemented with aromatic plants were higher (P<0.05) than those of animals of control group, whereas carcass parameters were not affected by treatments excepting for the slaughter weight that showed the same trend as growth performances. Meat quality traits, oxidative lipid stability and fatty acid profile were not influenced by aromatic plant supplementation. In conclusion, oregano and sage in form of dried leaves can be used in rabbit without adverse effects on performance, carcass characteristics and meat quality traits.

Dried artichoke bracts in rabbits nutrition: effects on the carcass characteristics, meat quality and fatty-acid composition.

In this study, the effects of the inclusion of artichoke bracts (AB) in rabbit diets on the carcass characteristics and rabbit meat quality were studied. A total of 120 rabbits aged 38 days were used and divided into three groups that were fed with different isonitrogenous and isocaloric diets supplemented with AB at 0%, 5% and 10%. The animals were single housed in wire cages at a temperature of 22±2°C and had free access to clean drinking water. At 96 days of age, 12 rabbits/group were slaughtered in an experimental slaughterhouse without fasting. The carcass was weighed and the weights of the skin and full gastrointestinal tract were recorded. Carcasses were chilled at +4°C for 24 h in a refrigerated room. The chilled carcass weight (CCW), dressing out percentage (CCW as percentage of slaughter weight), and the ratio of the head and liver were determined as a percentage of CCW. The reference carcass weight was also calculated. Carcasses were halved and the two longissimus dorsi (LD) muscles were excised. The left LD muscle was divided into two parts. The fore part was used to measure pH, colour and cooking losses. The hind part of the left LD was vacuum-packed, frozen at -20°C and then freeze-dried. Proximate composition, fatty-acid profile and thiobarbituric acid-reactive substances values were determined on freeze-dried samples. Results showed that carcass characteristics, LD muscle traits and its oxidative status were not affected by the AB supplementation, except for the meat ether extract content that increased from 0.68% to 0.94% on fresh matter basis with the increase of the AB supplementation (P<0.01). The α-linolenic acid proportion decreased with the increase of the AB supplementation from 3.58% to 2.59% in the LD muscle and from 4.74% to 3.62% in the perirenal fat, whereas the n-6/n-3 ratio increased significantly with increasing AB inclusion from 7.15 to 10.20 in the LD muscle and from 6.68 to 9.35 in the perirenal fat (P<0.01). Furthermore, no significant difference was found in preference among meat samples from each group. The enrichment of the rabbits diet with AB allows the production of rabbit meat with a good degree of unsaturation and low saturation, even if the n-6/n-3 ratio was slightly worse.

Morphometry, slaughtering performances, chemical and fatty acid composition of the protected designation of origin “Golden hump tench of Poirino highland” product

One hundred and thirty-two tench were photographed and a total of 13 landmarks were identified. Fish were grouped in four size classes on length basis and different shape descriptors were computed. Landmark configurations were superimposed. Size was computed as centroid size. The roundness coefficient, the log(partial area)/log(total area) ratio and the condition coefficient were calculated. Slaughtering performances and fillet composition analyses were performed. Shape variability was found primarily on cephalic area while head and tail regions were more homogeneous. A high correlation between centroid size and total length was found as well as a higher increase of the partial area than the total area justifying the hump shape of this tench. The scatter of relative warp 1 scores and centroid size for the four size classes has showed, with the increase of the length, a larger number of specimens that were characterised by a deep profile. Geometric morphometric approach produced a valuable tool in defining morphospaces for tench. Condition coefficient ranged from 1.24 to 1.29, without any significant difference among the size classes. Slaughtering performance resulted in agreement with those reported by other authors while VSI was lower. In fillets, the fatty acid profile was composed of about 30% of saturated fatty acids, 50% of monounsaturated fatty acids and 20% of polyunsaturated fatty acids with about 8% of docosahexaenoic acid. Atherogenic and thrombogenic indices were 0.58 and 0.42, respectively. Both n6/n3 and polyunsaturated/saturated fatty acids ratios were in accordance with value recommended for a healthy nutrition giving positive evaluation of the nutritional qualities of tench.

A description of ammonium content of output waters from trout farms in relation to stocking density and flow rates

Abstract Daily levels of ammonium content in the outflow water of an intensive trout farm and of a mountain pond stocked with rainbow trout were monitored. Output water was sampled for 30 days and analysed every 30 min by an automatic ion selective electrode system (Applikon ADI 2013); input water was also monitored. The ammonium output level was influenced more by atmospheric events than nitrogen excretion by fish. Observed data confirmed an overall ammonium excretion model previously estimated in both laboratory and field conditions. The high water flow, that characterises the intensive trout farm where the observations were made induced a high dilution of metabolites. Consequently, if the peaks of ammonium output did not reach values of 0.35–0.40 mg l −1 the environmental impact was limited and not easily detected. Our results allow us to affirm that the optimal level of water flow rate for effective zeolite-operated filtration is around 10.3 l t −1 s −1 .

Effect of diet chestnut tannin supplementation on meat quality, fatty acid profile and lipid stability in broiler rabbits

Abstract This study investigated the effect of chestnut tannins on meat quality in broiler rabbits. 72 commercial hybrid rabbits (mean body weight 740 g, 32 days old) were fed for 49 days with three diets containing 0%, 0.5% and 1.0% of a commercial chestnut wood extract (ENC®, Silvachimica srl), respectively. Eight rabbits per group were slaughtered at 12 weeks of age and at 24h post-mortem pH and colour were measured on the carcass. Moreover, both sides of m. longissimus thoracis (LT) were dissected. Left side was used for cooking losses whereas the other side was used for the determination of fatty acid profile and lipid oxidation. Data were statistically analyzed by one-way ANOVA. No differences were found in pH, colour and cooking losses, as well as the fatty acid profile of LT muscle and its relative health indexes. Concerning the antioxidant effect, the ENC shows a positive and significant effect at the inclusion level of 0.5%. In conclusion, the ENC has not undesirable side effects on the meat quality of rabbits, although further studies will be necessary to find the optimal diet inclusion level of ENC to elicit a stronger antioxidant effect in the rabbit meat.