Judul: Case Study of Nematode Parasite Infection in Dairy Cattle at PT Nusantara  Agri Sejati, Sukaraja District, Sukabumi Regency, Case Study of Nematode Parasite Infection in Dairy Cattle at PT Nusantara Agri Sejati Sukaraja District Sukabumi Regency
Abstrak: Produksi susu di Indonesia masih tergolong rendah. Indonesia hanya mampu memasok 21% kebutuhan susu, sebanyak 79% dipenuhi dari impor. Salah satu perusahaan susu sapi di Indonesia adalah PT Nusantara Agri Sejati. Permasalahan penurunan produksi susu sering diakibatkan oleh gangguan infeksi endoparasit salah satunya cacing nematoda. Manajemen kesehatan yang penting dilakukan yakni pemeriksaan infeksi cacing pada ternak. Data ini sangat penting sebagai acuan untuk melakukan pengobatan atau pengendalian parasit. Penelitian ini bertujuan mengidentifikasi jenis, menghitung prevalensi dan derajat infeksi parasit nematoda, serta mengidentifikasi faktor risiko intrinsik dan ekstrinsik yang berpengaruh terhadap kejadian infeksi nematoda di PT Nusantara Agri Sejati. Data diperoleh dari 34 sampel feses sapi yang diidentifikasi menggunakan metode flotasi dan Mc Master. Hasil pemeriksaan menunjukkan adanya infeksi Nematoda, jenis telur yang teridentifikasi adalah strongylid dan trichurid. Angka prevalensi infeksi mencapai 53% dengan nilai TTGT 108,87. Faktor yang berpengaruh terhadap kejadian infeksi Nematoda di PT NAS adalah faktor risiko ekstrinsik yakni sistem pemeliharaan, pengelolaan limbah feses, sumber dan penyimpanan pakan, program pemberian obat cacing yang tidak berkala, dan kondisi lingkungan., Milk production in Indonesia is still relatively low. Indonesia is only able to supply 21% of its milk needs, 79% of which is met by imports. One of the dairy companies in Indonesia is PT Nusantara Agri Sejati. The problem of decreased milk production is often caused by interference with endoparasite infections, one of which is nematode worms. Health management that is important to do is examination of helminthic infections in livestock. This data is very important as a reference for treating or controlling parasites. This study aims to identify the species, calculate the prevalence and degree of nematode parasite infection, and identify the intrinsic and extrinsic risk factors that influence the incidence of nematode infection at PT Nusantara Agri Sejati. Data were obtained from 34 cow faeces samples identified using the flotation and Mc Master methods. The examination results showed a nematode infection, the egg types identified were strongylid and trichurid. The infection prevalence rate reached 53% with the TTGT value of 108.87. Factors that influence the incidence of nematode infection at PT NAS were extrinsic risk factors, namely rearing systems, faecal waste management, feed sources and storage, occasional deworming programs, and environmental conditions.
Keyword: faktor risiko, manajemen pemeliharaan, nematoda, sapi perah

Judul: Case Study of Trematode Infection in Friesian Holstein Dairy Cattle at PT Nusantara Agri Sejati
Abstrak: Trematodosis merupakan salah satu masalah kesehatan pada sapi Friesian Holstein (FH) di Indonesia. Trematodosis bisa dikendalikan dengan memutus mata rantai infeksi. Penelitian ini bertujuan mengidentifikasi kejadian dan faktor risiko trematodosis sapi FH di PT Nusantara Agri Sejati (NAS). Data diperoleh dari koleksi sampel feses, lingkungan, inspeksi, dan wawancara dengan dokter hewan di PT NAS. Koleksi feses dilakukan secara perektal dari 34 ekor sapi bunting dan muda (dara) serta pengambilan sampel rumput dan tanah di empat titik sekitar lahan PT NAS. Sampel feses diperiksa dengan teknik filtrasi bertingkat. Hasil penelitian disajikan secara deskriptif menggunakan data kuantitatif dan kualitatif. Hasil pemeriksaan laboratorium menunjukkan sampel feses sapi mengandung telur cacing Trematoda. Prevalensi Trematodosis pada sapi di PT NAS tergolong rendah. Berdasarkan hasil wawancara narasumber, keberadaan inang antara seperti siput air pembawa larva beberapa saat ditemukan. Hal ini menjadi faktor risiko yang penting dalam kejadian infeksi Trematoda di dalam manajemen pemeliharaan dan sanitasi di PT NAS., Trematodiasis is a health problem in Holstein- Friesian (FH) cattle in Indonesia. Trematodiasis can be controlled by breaking the chain of infection. This study identified incidence and risk factors for trematodiasis of FH cattle in PT Nusantara Agri Sejati. Data were obtained from the collection of fecal samples, environment, inspections, and interviews with PT NAS veterinarian. Feces collection was carried out rectally from 34 pregnant and young cows (heifers) and grass and soil samples were taken at four points around PT NAS's land. Feces samples were examined with stratified filtration technique. The research results were presented descriptively using quantitative and qualitative data. The results of laboratory tests showed that only one cow feces samples contained Trematode eggs. Based on the results of interviews, the presence of intermediate hosts such as water snails was found for a while. This is an important risk factor for Trematode infection in maintenance and sanitation management at PT NAS.
Keyword: Holstein-Friesian, PT NAS, stratified filtration, trematode

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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