Judul: Methane and Carbon Dioxide Production in Dairy Cattle Feces Given Chopped and Ensiled Elephant Grass
Abstrak: Metana dan karbon dioksida dihasilkan melalui sistem pencernaan dengan jalur enterik dan feses. Pakan hijauan menjadi faktor penting yang memengaruhi produksi kedua gas ini. Perlakuan pada hijauan diduga dapat memberikan pengaruh pada produksi metana dan karbon dioksida. Ensilasi dan pencacahan merupakan perlakuan yang telah dikenal dan banyak digunakan untuk mengolah hijauan. Penelitian ini bertujuan untuk menganalisis produksi metana dan karbon dioksida yang dihasilkan oleh feses sapi perah dengan pakan rumput gajah dicacah dan diensilasi. Penelitian berlangsung dari Agustus 2020 hingga Februari 2021. Rancangan penelitian ini adalah rancangan bujur sangkar latin 4×4. Empat ekor sapi perah peranakan Friesian Holstein betina dalam masa kering digunakan dalam penelitian ini. Hijauan yang digunakan dalam penelitian adalah rumput gajah berumur 55 hari yang dikenakan empat perlakuan, yaitu FW (rumput gajah segar utuh), FC (rumput gajah segar dicacah), SW (silase rumput gajah utuh), dan SC (silase rumput gajah dicacah). Analisis proksimat dilakukan pada setiap bahan pakan. Penelitian dilakukan dalam empat periode dengan durasi waktu 21 hari tiap periode. Setiap sapi diberikan ransum lengkap (konsentrat ditambah hijauan yang telah diberi perlakuan) selama 21 hari, di mana 14 hari pertama digunakan untuk adaptasi dan 7 hari terakhir untuk koleksi feses. Feses yang telah dikumpulkan kemudian ditimbang. Feses diambil sebagian untuk dianalisis proksimat dan dimasukkan ke dalam sungkup tertutup untuk proses inkubasi gas. Kelompok dalam inkubasi gas yaitu kelompok tanpa pemberian EM4 dan kelompok dengan pemberian EM4 1%. Feses diinkubasi selama 8 minggu. Sampel gas diambil dari setiap sungkup tiap minggu untuk kemudian dianalisis menggunakan kromatografi gas. Perlakuan pencacahan dan ensilasi rumput gajah dapat meningkatkan konsumsi bahan kering dan koefisien cerna pakan (p<0,05). Efektivitas perlakuan dalam meningkatkan konsumsi bahan kering dan koefisien cerna pakan dapat dikategorikan menjadi SC > SW > FC > FW. Pencacahan dan ensilasi tidak berpengaruh nyata dalam produksi metana dan karbon dioksida dari feses sapi perah pada kedua grup. Pemberian EM4 1% pada inkubasi feses memberikan hasil berbeda nyata dalam produksi metana dan karbon dioksida dari feses sapi perah (p<0,05). Produksi metana dan karbon dioksida dipengaruhi beberapa faktor, seperti volatile solid feses dan durasi inkubasi. Pemberian perlakuan rumput gajah (ensilasi dan pencacahan) tidak berpengaruh terhadap produksi metana dan karbon dioksida yang dihasilkan dari feses sapi perah yang diinkubasi dalam sungkup tertutup. Penambahan EM4 1% pada feses sapi perah dapat meningkatkan produksi metana dan karbon dioksida., Methane and carbon dioxide are produced by digestive system through enteric and fecal pathway. Feed become a key factor which influence the production of methane and carbon dioxide. Application of forage treatments are expected to modulate in methane and carbon dioxide production. Ensiling and chopping are famous forage treatments that have been widely known and used. This research aims to measure methane and carbon dioxide production in dairy cattle feces given different forage treatments (ensiling and chopping). The research had been conducted from August 2020 to February 2021. The design of this research is 4×4 Latin square design. Four Frisian Holstein cows were used as the experimental animals. All cows were in dry period. Forage used in this research is 55 days old elephant grass and subjected to the following treatments: FW
Keyword: feses sapi perah, gas rumah kaca, karbon dioksida, metana, sapi perah

Judul: Evaluasi Gas Rumah Kaca (CH4, CO2 dan N2O) dari Feses Sapi FH Laktasi yang Diberi Pakan Rumput Gajah dan Jerami Padi
Abstrak: Livestock sector is one of potential sector to produces greenhouses gases from feces. FH (Frisien Holstein) is one of the dairy cows mostly raised in Indonesia. Feces production of FH approximately 18.45-36.9 kg per day. Dairy cows feces produces the main greenhouse gases such as CH4, CO2 and N2O. Dairy cows feces either solid or liquid has the potential to emit CH4, CO2 and N2O. The aim of this experiment was evaluate the production of greenhouse gases from lactating dairy cow feces that fed with elephant grass (EG) and rice straw (RS). This experiment was conducted from September to December 2014 in KUNAK, Animal Waste Processing and PAU Laboratory of Bogor Agriculture University, and Greenhouse Gases Laboratory of BALINGTAN. BALINGTAN method in measuring greenhouse gases was used in this research. Feces were collected as much as 1 kg in 24 hours and incubated for 8 weeks to measure greenhouse gases. CRD (complete random design) repeated measurements was used with 3 treatments : RS (100% rice straw), EG (100% elephant grass) and RSEG (50% rice straw+50% elephant grass). Measured variables were greenhouse gases (CH4, CO2, N2O), proximate feed analysis, feces proximate analysis, total of feces organic matter, C organic feces, N feces, ammonia (NH3) concentration, feces weight in 24 hours, dairy cows body weights, and feed consumption. The result showed that CH4 gas production from lactating dairy cow feces had no significant effect in each treatment (P>0.05). There was no differences on the CO2 production (P>0.05) between RS, EG, and RSEG but N2O production was higher in RS (P<0.05) than EG and RSEG. Different feeding significantly affected CH4 gas production in the first week (P<0.05), while for the second week until the last week of the study was not significant effect (P>0.05). The first week of CH4 measurement, generated the highest production on dairy cows in RS treatment and followed by RSEG, while EG treatment produces CH4 lower than RS and RSEG. Furthermore, CO2 production in the first week to the third week showed an increase volume in all treatments. In the third week until the sixth week showed a decline in CO2 gas production and increased back on the last week of incubation. Peak production of CO2 gas in all treatments occurred in the third week, it demonstrated the high content of digestible organic matter such as energy and protein and the declined of CO2 production caused by decreasing of digestible substrate. Production of greenhouse gases associated with the substrate that used by the bacteria which is the fiber has longer degradation process so CO2 gas produced slower. Furthermore, the highest production of N2O gas was produced from RS treatment (P<0.05). Fluctuation of N2O gas production was influenced by the concentration of NH3, N content of feces and the role of microbes during the feces incubation process. Generally, the production of CH4 and CO2 produced from dairy cows lactating feces was higher than N2O. The greenhouse gases produced from feces was associated with organic matter content, easily digestible substrate, and length of fermentation. Lactating dairy cow feces with elephant grass and rice
Keyword: elephant grass, greenhouse gases, lactating dairy cows feces, rice straw

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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