Judul: Case study: Taurus Dairy Farm, Tenjoayu, Cicurug, Sukabumi
Abstrak: There are a lot of factors that influence the variance of dairy milk production. In peral, it can be divided into two major factors, genetics and environment factors. A high value of genetics variance means that the environment has small effect in dairy milk production. In the real world. the true variance is impossible to know, so statistical methods are needed with the purpose of estimating them. Statistical analysis that is frequently used for analyzing tho woci.tion between the response and explanatory variable Is linear model. However, this analysis is restricted by the assumption that it can only involve variables that are considered fixed. Another approach is needed If the variables concerned arc random variables. Linear mixed model is a suitable method. because it provides analysis for both fixed and random variables. The result showed that the stage of lactation is the only flxed effect to be significant. Unstructured Covariance, based on the Ale value, is the best covariance struciure to model the random effects. N. final point, Varlour type is the most superi()r sire with the highest genetic contribution to its daughter" milk production, and by the maximum genetic progress,·compared to additional types.
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Judul: Milk Production Model Development
Abstrak: Dalam upaya meningkatkan tingkat produksi susu dalam negeri, Indonesia mendatangkan sapi perah dari Eropa. Perbedaan iklim antara daerah asal dan Indonesia diperkirakan berpengaruh besar pada produksi susu. Penelitian ini bertujuan menghitung besar pengaruh keragaman iklim dan faktor lainnya terhadap produksi susu sapi perah dan menyusun model prediksi produksi susu. Penelitian dilakukan di Kabupaten Semarang di tiga lokasi yaitu Kecamatan Getasan (1081m mdpl), Kecamatan Tengaran (702 mdpl), dan Kecamatan Ungaran Barat (418 mdpl). Data produksi susu, pemberian pakan dan minum harian sapi perah dikumpulkan melalui pengukuran langsung pada 265 ekor sapi dari Maret hingga Mei 2023. Umur sapi diperoleh dari wawancara, data suhu dan kelembaban melalui pengukuran langsung dengan thermo-hygrometer. Metode penelitian menggunakan analisis regresi. Hasil penelitian menunjukkan bahwa peningkatan produksi susu sejalan dengan meningkatnya umur. Faktor umur dapat menjelaskan keragaman produksi susu sampai 80%. Lebih lanjut keragaman produksi susu berbagai tingkat umur dipengaruhi secara nyata oleh kondisi iklim yaitu tingkat kepanasan atau kelengasan udara (Temperature Humidity Index-THI) serta jumlah konsentrat dan jumlah minum yang diberikan. Faktor ini dapat menjelaskan keragaman produksi susu pada tingkat umur sampai 20%. Hasil ini menunjukkan bahwa hampir semua keragaman produksi susu dapat dijelaskan oleh umur dan pemberian pakan/minum serta THI. Secara umum kondisi lingkungan yang nyaman bagi ternak ialah wilayah yang memiliki THI kurang dari 72. Pada THI yang tinggi sapi akan mengalami stress dan produksi susu menurun., In an effort to increase the level of domestic milk production, Indonesia imports dairy cows from Europe. The difference in climate between the area of origin and Indonesia is expected to have major effect on milk production. This study aims to calculate the effect of climate variability and other factors on milk production of dairy cows and to develop a milk production prediction model. The research was conducted in Semarang Regency in three locations, namely Getasan Subdistrict (1081 mdpl), Tengaran Subdistrict (702 mdpl), and West Ungaran Subdistrict (418 mdpl). Data on milk production, daily feeding and drinking of dairy cows were collected through direct measurement on 265 cows from March to May 2023. Cow age was obtained from interviews, temperature and humidity data through direct measurement with a thermo-hygrometer. The research method used regression analysis.The results showed that milk production increased in line with increasing age. The age factor can explain the variability of milk production up to 80%. Furthermore, the varaibility of milk production at various ages was significantly influenced by climatic conditions, namely the level of heat or air humidity (Temperature Humidity Index- THI) as well as the amount of concentrate and the amount of drinking water given. This factor can explain up to 20% of the variation milk production at age level. These results indicate that almost all of the variability in milk yield can be explained by age and feeding/drinking and THI. In general, comfortable environmental conditions for livestock are areas with THI of less than 72. At high THI, cows will experience stress so that milk production will decrease.
Keyword: milk production, multiple linear regression analysis, sapi perah, Dairy Cows, THI

Judul: Membran Komposit Kitosan-Nanopartikel Magnetik Fe3O4-Hidroksiapatit untuk Rekayasa Jaringan Tulang.
Abstrak: Composite membrane implants from biodegradable and biocompatible polymers such as chitosan, added with Fe3O4 magnetic nanoparticleshydroxyapatite (MHAP) is an alternative that is appropriate for bone tissue engineering. The MHAP was first synthesized using coprecipitation method with 3 different composition, with the ratio of Fe3O4 : hydroxyapatite is 3:7, 4:6, and 5:5 by mass. The composite membrane chitosan-MHAP (MK K-MHAP) was then synthesized by mixing a chitosan solution and the best MHAP composition (10, 20, 30, and 40% w/w of the mass of chitosan). Characterization using X-ray diffraction confirmed the formation of Fe3O4 and hydroxyapatite phase on the MHAP. The magnetic saturation value and size of Fe3O4 magnetic nanoparticles increase with the increasing Fe3O4 composition in MHAP and MK K-MHAP which characterized based on its magnetic hysteresis and particle size distribution curve, respectively. The morphology of the best composition of MHAP composite was analysed using transmission electron microscope. Molecular interactions in MK K-MHAP was characterized based on infrared spectra. Immersion test of MK K-MHAP showed optimum state at 30% mass MHAP composition in chitosan matrix with calcium concentration released about 1000 ppm within 144 hours.
Keyword: biomedical, chitosan, composite membrane, hydroxyapatite, magnetite