Judul: Termoregulatory response and shade occupation behaviour of dairy heifers PFH offered diet content
Abstrak: A research was conducted to study, the effect of energy diets and environmental conditions on termoregulatory and behaviour responses of dairy heifers. A 4 x 4 latin square design was used for data analysis using 4 dairy heifers and 4 treatments of feed energy for 21 days periods. The treatments were A (TDN : 55%), B (TDN : 60%), C (TDN : 65%), and D (TDN : 70%). All diets content 12 – 15 % of CP. Observed variables were environment factors (air temperature, relative humidty, THI, wind speed, and solar radiation) and termoregulatory responses (Tr, mTs, Tb, HR and RR), TDN intake, animal growth and their behaviour especially shade occupation. Data were analized by variance and/or regression analysis followed by the LSD for any significant difference among treatments. The results showed that TDN intake for A, B, C, D were 4.2, 4.3, 4.4 and 4.3 kg/d, respectively. There was no differences in body gain among treatments (P>0.05). The treatments significantly influenced the thermoregulatory responses (P<0.01). The D treatment resulted in more heat stress than that of the other treatments. Shade occupation showed significantly correlated to environtmental factors or TDN intake (P<0.01). It was concluded that the animals under 60-65% of TDN intake showed optimum growth rate without experiencing of severe heat stress; The combination of environmental conditions and higher feed energy intake increased heat load on dairy heifers.
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Judul: Effect of feeding time on physiological response of Fries Holland heifer fed with three levels of TDN of concentrate containing coconut oil
Abstrak: One of the greatest challenges to production facing dairy farmers in Indonesia is heat stress. Climatic conditions in Indonesia are such that the warm (or hot) is all year, there is intense solar radiant for an extended period of time, and there is generally the presence of high relative humidity. Thus heat stress is chronic in nature, there is often little relief from the heat during the evening hours, and intense bursts of combined high ambient temperature and humidity further depress performance. Some researchs have been done in Indonesia showed that physical modification of the environment (shading, cooling) and improved nutritional management practices are management strategies to minimize the effects of heat stress. However, the management strategies to minimizing of the heat stress have not been fully examined. The objective of the present study is to evaluate physiological responses of dairy heifer to feeding time when fed concentrate differences in TDN content. Six dairy heifers were randomly allocated to 1 of 6 treatments: two feeding times (5 am/6 pm or 8 am/4 pm) of concentrate with 70% or 75% of concentrate unsupplemented or supplemented with 3.5% coconut oil, in each of 6 periods of 14 d each in a 6 x6 Latin square design. The environmental conditions (air temperature, relative humidity, temperature humidity index, radiation, and wind velocity) and animals responses (heart rate, respiration rate, body temperature, rectal temperature, and skin temperature, feed consumption rate, chewing rate, and average daily gain) were then measured. The environmental condition were measured daily at 1 h intervals from 5 am to 8 pm. The animals responses were measured at the 4th, 8th, 12nd, 14th Keyword: physiological responses, coconut oil, feeding time, TDN day of each periode at 1 h intervals from 5 am to 8 pm. Tukey’s test, contras orthogonal analysis, and correlation analysis were used for statistical analysis among treatments. The results show that physiological responses were significantly lower on cattle which fed at 5 am & 6 pm than 8 am & 4 pm also for cattle which fed concentrates contained 3.5% coconut oil than not containing that with the same TDN (75%). Chewing velocity was higher on cattle fed concentrate containing 3.5% coconut oil than without coconut oil. Average daily gain were higher on cattle fed at 5 am & 6 pm than 8 am & 4 pm or fed with concentrate containing 3.5% coconut oil than without coconut oil. The conclusion is heat stress of dairy heifer could be reduced with managing feeding time and feeding with easily digestible nutrient.
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Judul: Konstruksi aritmetika kurva eliptik F(2m) supersingular dan non-supersingular untuk skema kunci publik ElGamal
Abstrak: Algoritme ElGamal adalah salah satu algoritme kunci publik dengan aritmetik modular p yang mempunyai struktur grip siklik Z(p). Tingkat keanaman algoritme ini terletak pada pemecahan masalah logaritme diskret dari Z(p). Akan tetapi, tingkat keamanan tadi tahun ke tahun semakin menurun yang disebabkan kemampuan pemecahan algoritme diskret semakin meningkat. Untuk memenuhi tingkat keamanan yang memadai dibutuhkan p yang cukup besar yang menyebabkan proses enkripsi dan dekripsi menjadi lambat.
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