Nitrate and Vitamin A Interrelationship in Sheep

Several researchers have demonstrated that dietary nitrate reduced liver stores of vitamin A in ruminants. However, it has not been shown whether the effect is due to a more rapid depletion of existing vitamin A stores or to a lowered depatic deposition of the vitamin. Two experiments were conducted to determine the effect of nitrate on plasma vitamin A, hepatic vitamin A and performance of lambs during a growing period (experiment 1) and vitamin A depletion and repletion periods (experiment 2)

Urea-Nitrate Interrelations in Sheep Under Feedlot Conditions

Three experiments were conducted to determine if measurable urea-nitrate interrelationships exist in sheep under feedlot conditions, and the extent of nitrogen utilization from urea and nitrate by sheep fed rations containing suboptimum quantities of protein. Dietary conditions imposed provided for the simultaneous adaptation of lambs to urea and sodium nitrate (experiment 1); an exposure to sodium nitrate without prior adaptation after lambs has been brought to a full feed on a ration containing urea (experiment 2); and the use of soybean meal, urea and sodium nitrate independently as protein supplements to rations providing suboptimum levels of crude protein (experiment 3)

Analisis Antrian Pada Loket Pembayaran Di Kcs Mart Kefamenanu

Penelitian ini bertujuan untuk mengetahui tingkat rata-rata kedatangan pelanggan dan tingkat rata-rata pelayanan di KCS Mart Kefamenanu, serta untuk menentukan model antrian yang optimal pada loket pembayaran di KCS Mart Kefamenanu. Model antrian yang digunakan dalam penelitian ini adalah model antrian jalur tunggal. Pengambilan data selama 7 hari kerja, pada tanggal 30 November - 06 Desember 2022, pukul 15.00 - 20.00 WITA. Data yang diambil adalah waktu antar kedatangan pelanggan dan lamanya pelayanan terhadap setiap pelanggan pada Loket Pembayaran di KCS Mart Kefamenanu. Berdasarkan pengumpulan data di lapangan maka diperoleh jumlah kedatangan pelanggan selama 7 hari pengamatan yaitu, loket pembayaran 1 sebanyak 590 pelanggan dengan rata-rata λ=17, dan loket pembayaran 2 sebanyak 242 pelanggan dengan rata-rata λ=28. Rata-rata waktu pelayanan terhadap pelanggan yang dilayani atau μ untuk kasir 1 sebesar 27 dan μ untuk kasir 2 sebesar 49

Giardia duodenalis in feedlot cattle from the central and western United States

<p>Abstract</p> <p>Background</p> <p><it>Giardia duodenalis </it>is a ubiquitous protozoan parasite that has emerged as a significant opportunistic human pathogen. <it>G. duodenalis </it>may have a deleterious effect on animal growth and performance, therefore its potential as a production limiting organism should not be discounted. We therefore undertook this study to determine management and environmental factors in feedlots that influence the prevalence and environmental load of <it>G. duodenalis </it>cysts in fecal material deposited by feedlot cattle in the central and western United States.</p> <p>Results</p> <p>Twenty two feedlots from 7 states were included in the study, and up to 240 fecal samples were collected from pen floors of up to 6 pens per feedlot. <it>Giardia duodenalis </it>cysts were identified and counted using direct immunofluorescent microscopy. The estimated overall point prevalence of <it>G. duodenalis </it>was 19.1%, representing feedlots from a wide range of climates and management systems. Pen-level prevalence varied from 0 to 63.3%, with pen-level shedding estimates ranging from 0 to 261,000 cysts/g feces. Higher environmental temperatures, increased animal density, and increased time in the feedlot were associated with a lower prevalence of <it>G. duodenalis</it>. Removing manure before placing a new group of cattle in a pen was associated with a decreased prevalence of <it>G. duodenalis </it>in fecal pats. Using coccidiostats as a feed additive was associated with a higher prevalence of <it>Giardia</it>.</p> <p>Conclusion</p> <p>Management practices could be employed that would limit the probability that feedlot cattle shed <it>G. duodenalis </it>in their feces and therefore potentially limit contamination of their environment.</p

Translating aboveground cosmic-ray neutron intensity to high-frequency soil moisture profiles at sub-kilometer scale

Above-ground cosmic-ray neutron measurements provide an opportunity to infer soil moisture at the subkilometer scale. Initial efforts to assimilate those measurements have shown promise. This study expands such analysis by investigating (1) how the information from aboveground cosmic-ray neutrons can constrain the soil moisture at distinct depths simulated by a land surface model, and (2) how changes in data availability (in terms of retrieval frequency) impact the dynamics of simulated soil moisture profiles. We employ ensemble data assimilation techniques in a “nearly-identical twin” experiment applied at semi-arid shrubland, rainfed agricultural field, and mixed forest biomes in the USA. The performance of the Noah land surface model is compared with and without assimilation of observations at hourly intervals, as well as every 2 days. Synthetic observations of aboveground cosmic-ray neutrons better constrain the soil moisture simulated by Noah in root-zone soil layers (0–100 cm), despite the limited measurement depth of the sensor (estimated to be 12–20 cm). The ability of Noah to reproduce a “true” soil moisture profile is remarkably good, regardless of the frequency of observations at the semi-arid site. However, soil moisture profiles are better constrained when assimilating synthetic cosmic-ray neutron observations hourly rather than every 2 days at the cropland and mixed forest sites. This indicates potential benefits for hydrometeorological modeling when soil moisture measurements are available at a relatively high frequency. Moreover, differences in summertime meteorological forcing between the semi-arid site and the other two sites may indicate a possible controlling factor to soil moisture dynamics in addition to differences in soil and vegetation properties

Translating aboveground cosmic-ray neutron intensity to high-frequency soil moisture profiles at sub-kilometer scale

Above-ground cosmic-ray neutron measurements provide an opportunity to infer soil moisture at the subkilometer scale. Initial efforts to assimilate those measurements have shown promise. This study expands such analysis by investigating (1) how the information from aboveground cosmic-ray neutrons can constrain the soil moisture at distinct depths simulated by a land surface model, and (2) how changes in data availability (in terms of retrieval frequency) impact the dynamics of simulated soil moisture profiles. We employ ensemble data assimilation techniques in a “nearly-identical twin” experiment applied at semi-arid shrubland, rainfed agricultural field, and mixed forest biomes in the USA. The performance of the Noah land surface model is compared with and without assimilation of observations at hourly intervals, as well as every 2 days. Synthetic observations of aboveground cosmic-ray neutrons better constrain the soil moisture simulated by Noah in root-zone soil layers (0–100 cm), despite the limited measurement depth of the sensor (estimated to be 12–20 cm). The ability of Noah to reproduce a “true” soil moisture profile is remarkably good, regardless of the frequency of observations at the semi-arid site. However, soil moisture profiles are better constrained when assimilating synthetic cosmic-ray neutron observations hourly rather than every 2 days at the cropland and mixed forest sites. This indicates potential benefits for hydrometeorological modeling when soil moisture measurements are available at a relatively high frequency. Moreover, differences in summertime meteorological forcing between the semi-arid site and the other two sites may indicate a possible controlling factor to soil moisture dynamics in addition to differences in soil and vegetation properties

Urea and Nitrate Interrelationships in Sheep Under Feedlot Conditions

Several sources of nonorotein nitrogen, including urea and nitrate, are known to be utilized by rumen microbes for protein synthesis after conversion to a common intermediate, ammonia. This has led to the speculation that the presence of urea may result in a decrease in the utilization of nitrate or its reduction products, thereby increasing the apparent toxicity of nitrate. The experiments reported herein were ccnducted to determine if measurable urea-nitrate interrelationahios exist in sheep under feedlot conditions, and the extent of nitrogen utilization from urea and nitrate by sheep fed rations containing otherwise suboptimum quantities of crude protein