Judul: Daya Tahan Pembekuan Semen Empat Genetik Ayam Lokal pada Program Kriopreservasi Plasma Nutfah Indonesia
Abstrak: Chicken is a very common animal in Indonesia, and has been shown high potential as meat and eggs producer. Semen cryopreservation as one way to preserve endangered local chicken breed. The purpose of this study was to compare the genetic quality by analyze of sperm quality of various local chicken breed, determine the best cyoprotectant concentration (dimethyl sulfoxide/ DMSO), glycerol, and dimethyl acetamide/ DMA) in ringer lactate egg yolk extender in different breed and to compare freezing capability among breed using the best concentration of cryoprotectant in each breed. The research was conducted into 5 step; 1) comparison of fresh semen quality among local chicken breed 2) determination the best DMSO concentration in Ringer's lactate diluent egg yolk (RLEY) of kampung chicken breed 3) determination of the best glycerol concentration in RLEY of sentul chicken breed 4) determination of the DMA concentration in RLEY of kampung broiler cross breed 5) to compare freezing capability among local chicken breed using the best cryoprotectan concentration of each breed. Step 1 to step 4 were design using completely randomized and step 5 using factorial design. The results showed that fresh semen of pelung chicken demonstrated higher quality compare to other. The use of 7% DMSO was the best concentration of frozen semen compared to 5% and 9% of kampung chicken breed. Glycerol 5% using was the best concentration in frozen semen compared with 7% and 9% of sentul chicken breed. For kampung broiler cross breed, 9% DMA more suitable compare to 5% and 7%. When compare between 5% glicerol, 7% DMSO, and 9% DMA for kampung chicken, sentul chicken, pelung chicken, and kampung broiler cross breed, 5% glicerol demonstrated the best cryoprotectan for all breed chicken. Recovery rate (RR) of sentul was higher than kampung chicken, sentul chicken, pelung chicken, and kampung broiler cross breed. Breed and type cryoprotectan influenced the decrease of spermatozoa motility during freezing process.
Keyword: chicken semen, DMA, DMSO, glycerol

Judul: Suplementasi Sodium Dodecyl Sulphate dan Vitamin E terhadap Kualitas Semen Cair Ayam Lokal yang Dipreservasi pada Suhu 5 oC
Abstrak: The objective of this experiment was to determine the effect of sodium dodecyl sulphate (SDS) and vitamin E supplementation to the lactate ringer-egg yolk (LREY) diluents on the pelung chicken semen preservation and to compare the semen quality of various local chicken breeds by in-vivo and in-vitro. This study was divided into several step; 1) SDS supplementation in the LREY diluent, 2) Vitamin E supplementation in the LREY diluent with best level of SDS, 3) The appeal test of local chickens semen quality with the best diluent in phase 2, 4) The appeal test of local chickens semen fertility and fertile period through artificial insemination in laying hens ISA Brown with the best diluent in phase 2. Step 1 to step 3 were design using a completely randomized repeated measurement with 4 replications, while step 4 was design using a completely randomized with 3 replications. Results of step 1 showed the sperm motility and viability in LREY added with 0.025% SDS (72.08±1.44% and 1.30±80.82%) was significantly higher (P<0.05) than 0% and 0.05% SDS at 24 hours of storage. No differences in sperm motility and viability between 0% and 0.05% SDS. The decrease of sperm motility and viability demonstrated that 0.025% SDS supplementation (4.17±2.89% and 4.65±1.63%) was significantly lower (P<0.05) than 0% and 0.05% SDS at 24 hours of storage. Results of step 2 showed sperm motility and viability in LREY with 0.025% SDS which supplemented with 2% of vitamin E (77.92±0.74% and 87.37±0.75%) was significantly higher (P<0.05) compared to 0%; 0.5%; 1% and 3% vitamin E at 12 hours of storage. The decrease of sperm motility and viability demonstrated 2% vitamin E supplementation (2.92±0.74% and 0.65±5.52%) was significantly lower than 0%; 0.5%; 1% and 3% vitamin E at 12 hours of storage. Results of step 3 showed chicken breeds affected on sperm motility and viability (P<0.05). During the storage period, the highest sperm motility and viability were demonstrated by pelung chicken. Sperm motility and viability of pelung chicken (72.50±1.12% and 81.94±1.12%) were higher than sentul chicken (68.33±1.05% and 80.95±1.06%), merawang chicken (65.83±1.54% and 76.83±1.26%) and kampung chicken (64.17±1.54% and 77.96±1.38%) at 24 hours storage. Results of step 4 showed chicken breeds affect on fertility (P<0.05), but did not affect the fertile period. Fertility of pelung chicken (62.10±2.76%) was higher than kampung chicken (49.47±3.68%) and merawang chicken (48.15±1.85%), but no difference between sentul chicken fertility (57.94 ± 4.83%) with others. The longest fertile period was demonstrated by pelung chicken (11.33±0.33 days), followed by sentul chicken (11.00±0.58 days), kampung chicken (10.33±0.88 days) and merawang chicken (10.00±0.58 days). In conclusion, SDS 0.025% and 2% vitamin E supplementation in LREY could maintain the sperm motility and viability during 72 hours of storage at 5 °C. Sperm motility and viability of pelung chicken were higher than sentul chicken, kampung chicken and merawang chicken during 72 hours of storage at 5 °C. The highest fertility was demonstrated by pelung chicken and the lowest by merawang chicken. Fertile period of four chicken breeds ranged from 10 to 11 days.
Keyword: sperm, SDS, vitamin E, fertility, fertile period

Judul: Bifurkasi Hopf pada Model Siklus Bisnis Kaldor Kalecki tanpa dan dengan Waktu Tunda
Abstrak: Business cycle model is one of dynamical system models in economic. One of the business cycles model is Kaldor-Kalecki model. Kaldor-Kalecki business cycle model that is written in delayed defferential equations, is a business cycle model that involves gross product and capital stock of a company. In this paper Kaldor-Kalecki business cycle model is analyzed using both nondelay and delay in time of capital stock. By Taylor expansion for the time delayed model, an analysis of stability around the fixed points has been done. Furthermore, by using Hopf bifurcation theorem, it can be shown that there exists periodic orbits and limit cycle. In the nondelayed model, changing the parameter of goods market could lead to the occurrence of Hopf bifurcation and the existence of limit cycle. Similarly, for the delayed model, it has been shown that changing the time delay parameter may result in the occurrence of Hopf bifurcation and limit cycle.
Keyword: