Judul: Penggunaan Feed Additive Tepung Daun Sirih (Piper betle L.) pada Ternak Ruminansia sebagai Salah Satu Upaya Mitigasi Metan
Abstrak: This research was conducted using In vitro technique for 48 hours of incubation time. The aim was to evaluate supplementation of Betel leaf meal to decrease methane production. Methane produced in the rumen was estimated by using data of volatile fatty acids (VFA) partial concentration, particularly three main acids, i.e. acetic acid, propionic acid and butyric acid. The experiment used block randomized design with three replicates and four treatments. The treatments were 0%, 1%, 2%, and 3% of betel leaf meal in feed. The results showed that suplementation of Betel leaf meal decreased methane and total gas production. Betel leaf meal also tended to decrease protozoa population (P<0.1), and increased propionic acid (C3) proportion and butiric acid (C4) proportion (P<0.05). The best dose of Betel leaf meal to reduce methane and to maintain optimum rumen condition was 2%.
Keyword: VFA, methane (CH4), gas production, betel leaf meal

Judul: Penambahan tepung daun sirih (Piper betle L.) dalam ransum untuk mengobati dan mencegah penyakit mastitis subklinis pada sapi perah
Abstrak: Mastitis is one of the most costly problems in dairy industry, particularly subclinical mastitis which is hard to be identified visually. The use of antibiotic to prevent and cure it had contribution on emergence of antibiotic resistant bacteria and their transmission from livestock to human. An alternative antibacterial compound is needed to replace antibiotic use as feed additive such as betel leaf (Piper betle L.), but it must be investigated its effect on rumen fermentation condition before it is fed to mastitis cow. The purpose of this research was to elaborate the addition of betel leaf in dairy cow ration as an effort to prevail over subclinical mastitis and increase milk production. The research was consisted of two stages; 1) In vitro study of betel leaf meal (BLM) addition effect on antimastitis trough rumen fermentation test and viability of rumen microorganisms, 2) In vivo study of betel leaf meal addition into ration on lactating cow infected by subclinical mastitis. In vitro study consisted of three experiments i.e a) antibacterial activity test of BLM on Staphylococcus sp. growth, b) effect of BLM on rumen fermentation; and c) effect of BLM on viability of rumen microorganism. Five BLM level of 0, 2, 4, 6, and 8% in concentrate feed were used as treatment treatment and 4 rumen liquors were taken as replicates. Elephant grass was used as fiber source. Parameters observed were a) inhibition zone; b) number of rumen protozoa and bacteria; c) VFA production, NH3 concentration, dry matter (DM) and Organic Matter (OM) digestibility. In vivo study was conducted using 12 heads of lactating cows with lactation period 2 until 5. They were identified before using IPB-1 reagent. They were grouped into five treatments and treated for 21 days. The treatments were 0, 2% given daily, 4 % given daily, 2% given skip a day, and 4 % given skip a day. The result showed that the highest the level of BLM addition, the highest the inhibition of BLM on Staphylococcus sp. growth before fermentation. Meanwhile addition of BLM did not differ among treatments after fermentation. The increment of BLM level significantly decreased rumen protozoa (P<0.05), but did not affect number of bacteria. VFA production significantly increase (P<0.01), but did not affect NH3 concentration, DM, and OM digestibility. The increment of VFA was due to the increment of bacteria population thus fermentation process optimally occurred when given 2% of BLM. The results of in vitro study indicated that 2% and 4% can be further used for in vivo experiment. The result of in vivo study showed that 2% addition of BLM given daily significantly increased average milk production of fat-uncorrected (FUCM 4%) and 2% addition of BLM given skip a day significantly increased average milk production of fat-corrected (FCM 4%). Furthermore, addition of 2% BLM given daily significantly affect (P<0.05) milk composition, somatic cell count, but did not affect IgG. Addition of BLM more than 4% and given daily tended to lower milk quality. It is concluded that the best level of betel leaf in in vitro study is 2% of BLM in
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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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