​Effect of Hydrilla verticillata in Feed on Production Performance and Carcass Characteristics of Thai Native Chickens

Background: Producing Thai native chickens through feed commercial is costly. To reduce the cost, native chicken could be fed with local plants or agricultural waste. Hyrrilla verticillate, a dominate macrophyte in Songkhla Lagoon, contain high crude protein and nitrogen free extract. Therefore, this research studied the use of Hydrilla verticillate in Thai native chicken diet on production performance, carcass characteristics and production cost. Methods: The experiment was executed in a completely randomized design (CRD) with 180 one-day-old commercial Thai native chicks. Four dietary treatments supplemented with 0%, 5%, 10% and 15% Hydrilla verticillata were formulated for three different phases of the experimental chickens: starter (1-4 weeks), grower (5-8 weeks) and finisher (9-12 weeks). Two chickens from each replicate were chosen for the carcass characteristics study. Result: During the starter phase, there was no notable effect shown among the chickens fed with the diet containing Hydrilla verticillata in terms of feed intake (FI) and body weight gain (BWG) (P greater than 0.05). The control chickens had best feed conversion ratio (FCR) (P less than 0.05), while the grower and the finisher periods, provided with different levels of Hydrilla verticillata, revealed no apparent differences (P greater than 0.05) concerning FI, BWG and FCR. Considering carcass characteristics, there were significant differences in live weight (LW) (P less than 0.05). But, no significant differences between treatments for hot carcass percentage, pectoralis majors, pectoralis minorstrip, thighs, wings, drumsticks and total edible carcass (P greater than 0.05). There were also statistical divergences regarding gizzard weight (GW) (P less than 0.05).

Jagd auf den Adlermörder — Entdeckung eines neuen Cyanotoxins

Hunting down the eagle killer: Vacuolar myelinopathy is a neurological disease affecting wildlife — including the iconic bald eagle — in the United States. Its cause has been elusive for decades, but its occurrence has been linked to the cyanobacterium Aetokthonos hydrillicola colonizing the invasive aquatic plant Hydrilla verticillata. In a recent study, we found that A. hydrillicola produces a novel highly toxic biindole alkaloid (aetokthonotoxin), and proved that it is causing the disease.

Comparison of generic and proprietary aquatic herbicides for control of invasive vegetation; part 3 : submersed plants

Herbicide selection is key to efficiently managing nuisance vegetation in our nation’s waterways. After selecting the active ingredient, there still remains multiple proprietary and generic products to choose from. Recent small-scale research has been conducted to compare the efficacy of these herbicides against floating and emergent species. Therefore, a series of mesocosm and growth chamber trials were conducted to evaluate subsurface applications of the following herbicides against submersed plants: diquat versus coontail (Ceratophyllum demersum L.), hydrilla (Hydrilla verticillata L.f. Royle), southern naiad (Najas guadalupensis (Sprengel) Magnus), and Eurasian watermilfoil (Myriophyllum spicatum L.); flumioxazin versus coontail, hydrilla, and Eurasian watermilfoil; and triclopyr against Eurasian watermilfoil. All active ingredients were applied at concentrations commonly used to manage these species in public waters. Visually, all herbicides within a particular active ingredient performed similarly with regard to the onset and severity of injury symptoms throughout the trials. All trials, except diquat versus Eurasian watermilfoil, resulted in no differences in efficacy among the 14 proprietary and generic herbicides tested, and all herbicides provided 43%–100% control, regardless of active ingredient and trial. Under mesocosm and growth chamber conditions, the majority of the generic and proprietary herbicides evaluated against submersed plants provided similar control.

Effects of Water Depth on the Growth of the Submerged Macrophytes Vallisneria natans and Hydrilla verticillata: Implications for Water Level Management

Water level is one of the most important factors affecting the growth of submerged macrophytes in aquatic ecosystems. The rosette plant Vallisneria natans and the erect plant Hydrilla verticillata are two common submerged macrophytes in lakes of the middle and lower reaches of the Yangtze River, China. How water level fluctuations affect their growth and competition is still unknown. In this study, three water depths (50 cm, 150 cm, and 250 cm) were established to explore the responses in growth and competitive patterns of the two plant species to water depth under mixed planting conditions. The results show that, compared with shallow water conditions (50 cm), the growth of both submerged macrophytes was severely suppressed in deep water depth (250 cm), while only V. natans was inhibited under intermediate water depth (150 cm). Moreover, the ratio of biomass of V. natans to H. verticillata gradually increased with increasing water depth, indicating that deep water enhanced the competitive advantage of V. natans over H.verticillata. Morphological adaptation of the two submerged macrophytes to water depth was different. With increasing water depth, H. verticillata increased its height, at the cost of reduced plant numbers to adapt to poor light conditions. A similar strategy was also observed in V. natans, when water depth increased from 50 cm to 150 cm. However, both the plant height and number were reduced at deep water depth (250 cm). Our study suggests that water level reduction in lake restoration efforts could increase the total biomass of submerged macrophytes, but the domination of key plants, such as V. natans, may decrease.

Pembesaran Ikan Nila (Oreochromis niloticus) pada Budidaya Sistem Resirkulasi Menggunakan Filtrasi Tanaman Hydrilla verticillata dan Ceratophyllum demersum

Penelitian ini mengkombinasikan tanaman Hydrilla verticillata dengan Ceratophyllum demersum sebagai filter pada budidaya ikan Nila sistem resirkulasi. Tujuan penelitian yaitu untuk mengetahui tingkat pertumbuhan ikan Nila pada budidaya sistem resirkulasi. Filtrasi yang digunakan pada budidaya sistem resirkulasi yaitu tanaman H. verticillata dan C. demersum. Metode penelitian menggunakan rancangan acak lengkap (RAL). Adapun parameter yang diamati berupa kelangsungan hidup ikan, pertumbuhan mutlak, laju pertumbuhan spesifik (SGR), Feed Conversion Ratio (FCR) dan kualitas air. Kelangsungan hidup ikan selamat pemeliharaan yaitu 100%. Pertumbuhan bobot mutlak individu berkisar 8.76 sampai 16.6 gr/minggu. Laju pertumbuhan spesifik ikan Nila berkisar 2.74 sampai 4.49%. Nilai FCR sangat bagus yaitu 1.2 dan rata-rata nilai suhu, pH dan DO masih pada kisaran yang layak untuk pertumbuhan ikan Nila. Selama pemeliharaan hanya dilakukan satu kali pergantian air. Budidaya sistem resirkulasi tersebut sangat efektif dan efesien untuk diterapkan, terutama pada wilayah dengan ketersediaan air yang terbatas.

EFEKTIFITAS TANAMAN HYDRILLA VERTICILLATA, RUMPUT GAJAH, ECENG GONDOK DALAM PEMBUATAN BIOGAS DENGAN BAHAN DASAR KOTORAN SAPI

Biogas merupakan gas mudah terbakar yang dihasilkan dari proses fermentasi bahan-bahan organik oleh bakteri anaerob. Senyawa tersebut didalam digester akan dikonversi menjadi senyawa metan yang dapat dibakar sebagai sumber energi. Bahan tersebut adalah kotoran sapi, tanaman hydrilla verticillata, tanaman eceng gondok, dan tanaman rumput gajah. Pada penelitian kali ini mencoba untuk memanfaatkan bahan-bahan kombinasi antara Kotoran sapi dengan variasi ketiga tanaman dengan perbandingan 2 : 1 dan kombinasi variasi tanaman dengan perbandingan 1 : 1. Untuk membandingkan 3 tanaman tersebut manakah yang optimal menghasilkan biogas. Parameter yang dianalisa terdiri dari kadar air, C/N rasio, suhu, tekanan, lama nyala api dan kadar gas metan. Hasil penelitian menunjukkan bahwa biogas terbaik diperoleh pada waktu fermentasi selama 30 hari pada variasi campuran bahan kotoran sapi dengan hydrilla verticillata pada perbandingan 2 : 1 dengan kadar air sebesar 41,3%, rasio C/N sebesar 21,5%, 50,4% kadar gas metan. Dan ditandai dengan kenaikan suhu mencapai 35oC juga dengan nyala api paling lama yaitu selama 72 detik dengan menggunakan kompor portable

Endoglucanase Activity of Novel Aspergillus sydowii Isolate WIU-01 and Application for Hydrophyte Degradation

<p>Many eutrophic lakes contain rapidly growing hydrophytes. Overgrown biomass is usually me-chanically harvested and thrown away, leading to resource waste and secondary environmental pollution. Microbial degradation is an economically and environmentally friendly approach for managing hydrophytic waste, fuelling the search for efficient biomass degraders. Here, we present isolation and characterization of Aspergillus sydowii WIU-01, a novel cellulolytic fungus. Strain WIU-01 was isolated from air. The degradation rate (29.75 vs. 21.95%) and endoglucanase activi-ty (0.31 vs. 0.16 U mL–1) of the fungus were higher in Canna indica (emergent plant) medium than in Hydrilla verticillata (submerged plant) medium, accordingly. Further, fungal endoglucanase ac-tivity was significantly positively correlated with the degradation rate, neutral detergent fiber con-tent, and acid detergent fiber content of hydrophyte powder. Fungal biomass was significantly negatively correlated with reducing sugar and cellulose content of hydrophyte medium, but was significantly positively correlated with hemicellulose, acid detergent lignin, and ash content of the medium. Collectively, these observations indicate that A. sydowii decomposes emergent and sub-merged plant mass without acid–base sample pretreatment, albeit its endoglucanase activity is rela-tively low. This highlights the role of cellulolytic microorganisms in the natural environment and the notion that the environment can be a source of cellulolytic microorganisms for potential envi-ronmentally friendly applications.</p>