1,501 research outputs found

    Valuasi Ekonomi Hutan Mangrove di Wilayah Pesisir Desa Boroko Kabupaten Bolaang Mongondow Utara Provinsi Sulawesi Utara

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    Ekosistem hutan mangrove merupakan salah satu sumberdaya alam wilayah pesisir yang mempunyai fungsi dan manfaat sangat besar, antara lain secara fisik, biologis, dan ekonomi, dengan fungsi utama sebagai penyeimbang ekosistem dan penyedia berbagai kebutuhan hidup bagi manusia dan mahluk hidup lainnya. Kabupaten Bolaang Mongondow Utara merupakan salah satu wilayah pesisir yang memiliki ekosistem mangrove di mana ekosistem hutan mangrove yang ada memiliki luas 1.670,81 Ha luas keseluruhan, di mana Desa Boroko merupakan salah satu desa potensi hutan mangrove dengan jumlah luas persebaran sebesar 101 Ha, yang mengalami degradasi antara lain di beberapa titik telah dialih fungsikan untuk kegiatan perkebunan cengkeh, penebangan yang dijadikan kayu bakar, pembukaan jalan, tambak, dan permukiman dengan luas indikatif kerusakan sebesar 4 Ha. Penelitian ini bertujuan untuk mengetahui nilai ekonomi total hutan mangrove setelah dipetakan tingkat kerusakan dan memperhitungkan nilai pemulihannya. Dengan metode analisis yang digunakan antara lain analisis tingkat kerusakan menggunakan metode NDVI (Normalized Difference Vegetation Index), dan analisis nilai ekonomi total kawasan menggunakan metode analisis kuantitatif dengan pendekatan valuasi ekonomi. Hasil penelitian menunujukan nilai manfaat total hutan mangrove di Desa Boroko sebesar Rp.261.210.638.132.-/Tahun

    Effect of dietary supplementation with insect fats on growth performance, digestive efficiency and health of rabbits

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    Background: The present work aimed at evaluating the effect of the dietary replacement of soybean oil (S) by two types of insect fats extracted from black soldier fly larvae (H, Hermetia illucens L.) and yellow mealworm larvae (T, Tenebrio molitor L.) on growth performance, nutrient digestibility, blood parameters, intestinal morphology and health of growing rabbits. Methods: At weaning, 200 crossbred rabbits (36 days old) were allotted to five dietary treatments (40 rabbits/group): a control diet (C) containing 1.5% of soybean oil and four experimental diets where soybean oil was partially (50%) or totally (100%) substituted by H (H50 and H100) or T (T50 and T100) fats. Total tract digestibility was evaluated on 12 rabbits per treatment. The growth trial lasted 41 d and, at slaughtering (78 days old), blood samples were collected from 15 rabbits per treatment, morphometric analyses were performed on duodenum, jejunum and ileum mucosa, and samples of liver, spleen and kidney were submitted to histological evaluation. Results: No difference was observed between the control and the experimental groups fed insect fats in terms of performance, morbidity, mortality and blood variables. The addition of H and T fats did not influence apparent digestibility coefficients of dry matter, protein, ether extract, fibre fractions and gross energy. Gut morphometric indices and organ histopathology were not affected by dietary inclusion of H and T fats. Conclusions: H and T fats are suitable sources of lipid in rabbit diets to replace soybean oil without any detrimental effect on growth performance, apparent digestibility, gut mucosa traits and health

    Evaluation of carcass and meat traits of Muscovy duck fed with black soldier fly partially defatted meal

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    The aim of this study was to evaluate the carcass characteristics and breast meat quality in Muscovy duck (Cairina moschata domestica) fed different inclusion levels of a partially defatted black soldier fly larva (BSF) meal. A total of 256 Muscovy ducklings (average live weight, LW: 71.32\ub12.70 g) were reared from day 3 to day 48 and randomly allotted in 32 pens (8 replicates/treatment). Four different diets were formulated with increasing substitution level of corn gluten meal with BSF larva meal (0, 3, 6 and 9%; BSF0, BSF3, BSF6 and BSF9, respectively) and divided in 3 feeding phases: starter (1-14 days), grower (14-35 days) and finisher (35-48 days). At day 48, 2 animals/replicate were slaughtered and dissected to determine their carcass yields. The weights of spleen, bursa of Fabricius, liver, heart and abdominal fat were recorded. Breast and thigh muscles were then excised from 16 ducks/treatment and weighted. Ultimate pH (pHu) and L*, a*, b* colour values were then measured on breast muscle. The collected data were tested by means of oneway ANOVA evaluating the effect of dietary BSF inclusion level by polynomial contrasts. Significance was declared at P<0.05. The inclusion of BSF did not affect final LW (2,515.68\ub192.42 g on average). Hot and cold carcass weights showed a quadratic response (P<0.05) to increasing BSF larva meal, with a minimum corresponding to BSF6; however, refrigeration losses were not affected by treatments. Weight of spleen, bursa of Fabricius, liver and heart did not differ among treatments. The weight of abdominal fat showed a quadratic response to increasing BSF meal with a minimum corresponding to BSF6 group (P<0.05). Breast and thigh yields, pHu and L*, a*, b* colour values did not differ among groups. With the exception of BSF6, the inclusion of BSF meal did not affect meat traits and carcass characteristics, confirming the potential use of BSF meal in Muscovy duck diets

    Chitinase and insect meal in aquaculture nutrition: a comprehensive overview of the latest achievements.

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    The aquaculture industry is looking for sustainable alternatives to conventional fish meals in fish feed, and insect-based meals are proving to be a promising solution. These meals are nutritionally optimal as they have a high protein content and an ideal amino acid profile. However, the presence of chitin, a component of the insect exoskeleton in these meals presents both an opportunity and a challenge. Chitosan, a derivative of chitin, is known to improve the physiological functions of fish, including growth, immunity, and disease resistance. While chitin and its derivative chitosan offer several physiological benefits, their presence can affect the digestibility of feed in some fish species, making the inclusion of insect-based meals in aquafeeds complex. While studies suggest positive effects, some problems, such as reduced growth rates in certain species, emphasize the need for further research on chitin digestion in fish. Chitinase, an enzyme that breaks down chitin, is being investigated as a potential solution to improve the nutritional value of insect meals in aquafeed. This review provides a comprehensive analysis of the applications, benefits, and challenges of using chitinase in aquaculture, highlighting the enzyme’s role in improving feed digestibility, disease control, and environmental sustainability. Extensive research is required to fully understand the potential of chitinase enzymes in aquaculture and to optimize their applications in this dynamic field. Overall, this review provides insight into the evolving landscape of insect-based meals and the applications of chitinase enzymes within sustainable aquaculture practices

    Magnetic ground state of the Ising-like antiferromagnet DyScO3_3

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    We report the low temperature magnetic properties of the DyScO3_3 perovskite, which were characterized by means of single crystal and powder neutron scattering, and by magnetization measurements. Below TN=3.15T_{\mathrm{N}}=3.15 K, Dy3+^{3+} moments form an antiferromagnetic structure with an easy axis of magnetization lying in the abab-plane. The magnetic moments are inclined at an angle of ±28\sim\pm{28}^{\circ} to the bb-axis. We show that the ground state Kramers doublet of Dy3+^{3+} is made up of primarily ±15/2|\pm 15/2\rangle eigenvectors and well separated by crystal field from the first excited state at E1=24.9E_1=24.9 meV. This leads to an extreme Ising single-ion anisotropy, M/M0.05M_{\perp}/M_{\|}\sim{0.05}. The transverse magnetic fluctuations, which are proportional to M2/M2M^{2}_{\perp}/M^{2}_{\|}, are suppressed and only moment fluctuations along the local Ising direction are allowed. We also found that the Dy-Dy dipolar interactions along the crystallographic cc-axis are 2-4 times larger than in-plane interactions.Comment: 9 pages and 6 figures; to be published in Phys. Rev.

    Use of rice protein concentrate in rainbow trout feeding: preliminary results

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    During the past decades, the fishery industry has excessively used the world fish captures to produce fishmeal and fish oil in order to prepare feed for aquaculture diets. This has led to a drastic reduction of several fish populations (Hardy, 1999; FAO, 1999). At present 70% of the oil and 34% of fishmeal obtained from captures are used for aquaculture industry and, if the aquaculture production will continue to increase as predicted, in a short time it will absorb the entire world oil and fish meal production. Moreover, since fish meal still constitutes an important part of the feed formula for cultivated fish and since a further increase of fish meal availability will not be possible (Hardy, 2001), its price is expected to continue to increase (Tacon, 1998)

    Effects of Tenebrio molitor larvae meal inclusion in rainbow trout feed: myogenesis-related gene expression and histomorphological features

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    The effects of Tenebrio molitor larvae meal (TM) dietary inclusion in rainbow trout diet were evaluated on muscular growth using gene expression and histomorphological features of liver, spleen, kidney, anterior and posterior gut through histopathological analyses. Two hundred fifty-two grow-out rainbow trout were fed four experimental diets containing increasing levels of TM: 0% (TM0), 5% (TM25), 10% (TM50), and 20% (TM100) corresponding to different levels of fish meal replacement (0, 25, 50, and 100%, respectively). Muscular growth was evaluated analysing the expression of various genes involved in different steps of myogenesis. Among the analysed genes, only MyoD expression resulted significantly higher in fish fed TM100 compared to fish fed TM0. The gut histomorphology was not affected by TM dietary inclusion and villus height differs from anterior and posterior segments regardless of the fed diet. Histopathological alterations were observed in all the sampled organs for all the dietary treatments; however, dietary TM inclusion did not influence either development or severity of the observed histopathological changes. The results obtained confirmed the safe utilisation of TM as an alternative protein source in rainbow trout diets and highlighted the necessity to deepen the studies of TM effect on the myogenesis process, especially at a molecular level.Highlights Rainbow trout can effectively be fed with a TM protein source. Total FM substitution by TM (TM100) decreased MyoD gene expression. Increasing TM dietary inclusion did not influence gut histomorphology
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