Judul: Productivity Of Friesian Holstein Dairy Cattle Based on Population, Lactation Percentage and Microclimate in BPTSP HPT Cikole
Abstrak: Berbagai faktor dapat mempengaruhi produksi susu, diantaranya adalah faktor populasi ternak pada satu peternakan, persentase laktasi, dan lingkungan. Evaluasi produktivitas sapi perah berdasarkan populasi, persentase laktasi, dan mikroklimat di Balai Pengembangan Ternak Sapi Perah dan Hijauan Pakan Ternak (BPTSP HPT) Cikole pada tahun 2017-2019 belum dilakukan, sehingga dilakukan penelitian untuk melihat hubungan populasi, persentase laktasi, dan mikroklimat yang berkaitan dengan suhu, kelembaban, curah hujan, dan Temperature Humidity Index (THI) terhadap produksi susu. Penelitian ini juga mengamati hubungan mikroklimat terhadap populasi dan persentase laktasi. Penelitian ini dilaksanakan pada bulan November-Desember 2020, bertempat BPTSP HPT Cikole, Lembang, Kabupaten Bandung Barat, Jawa Barat. Data penelitian ini terdiri atas data populasi ternak sapi perah 111 ekor, catatan produksi susu yaitu produksi susu sapi perah FH yang dipelihara dari tahun 2017 sampai 2019. Data mikroklimat berupa suhu, kelembaban udara dan curah hujan pada tahun yang sama diperoleh dari Balai Penelitian Tanaman dan Sayuran (Balitsa) Cikole. Data diolah menggunakan Microsoft Excel 2016 dan data dianalisis secara deskriptif, regresi dan korelasi yang diuji menggunakan software Microsoft Excel 2016 dan SAS 9.2. Produktivitas peternakan di BPTSP HPT Cikole berdasarkan jumlah populasi, persentase laktasi dan produksi susu mengalami perubahan yang berfluktuasi pada periode 2017 sampai dengan 2019. Berdasarkan analisis regresi dan korelasi terdapat pengaruh yang nyata antara populasi dan persentase laktasi terhadap produksi susu dengan nilai R2 80,72% dan 84% hal ini dikarenakan meningkatnya populasi berarti terjadi kelahiran pedet sehingga ternak laktasi akan bertambah. Terdapat pula pengaruh yang nyata antara curah hujan dan kelembaban terhadap populasi dengan nilai R2 40,28% dan 33,36%, serta suhu dan curah hujan terhadap persentase laktasi dengan nilai R2 46,74% dan 78,08%. Hasil regresi dan korelasi pengaruh mikroklimat secara umum terhadap produksi susu tidak berpengaruh nyata sehingga dapat disimpulkan BPTSP HPT Cikole berhasil menanggulangi efek perubahan mikroklimat., Various factors affected milk production, such as livestock population on one farm, proportion of lactation, and environment. Evaluation of dairy cattle productivity based on population, proportion of lactation, and microclimate at the Balai Pengembangan Ternak Sapi Perah Hijauan Pakan Ternak (BPTSP HPT) in 2017-2019 has yet been carried out, therefore a study was conducted to observe the relationship between population, the proportion of lactation and microclimate related to temperature, humidity, precipitation and Temperature Humidity Index (THI) on milk production. This study also considered the relationship of the microclimate to the population and proportion of lactation. This research was conducted in November-December 2020 at BPTSP HPT Cikole, Lembang, West Bandung Regency, West Java. This study's data consisted of 111 dairy population data, records of milk production, namely the production of FH dairy cattle, in which were collected from 2017 to 2019. Microclimate data in temperature, air humidity, precipitation and Temperature Humidity Index (THI) in the same year were obtained from the Balai Penelitian Tanaman dan Sayuran (Balitsa) Cikole. The data were processed using Microsoft Excel 2016, and the data were analyzed descriptively, regression and testing using Microsoft Excel 2016 and SAS 9.2 software. Livestock productivity in BPTSP HPT Cikole based on population size, the proportion of lactation and milk production has fluctuated from 2017 to 2019. Based on regression analysis and
Keyword: Friesian Holstein (FH), lactation percentage, microclimate, milk production, population

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: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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