4,650 research outputs found
Forage Quality as Related to Mineral Concentrations in Tropical Regions
Often tropical forages contain deficient or toxic concentrations of minerals for grazing livestock (McDowell, 2003). Tropical forages generally contain less of the more essential minerals than species grown in temperate regions (McDowell & Valle, 2000). Mineral elements in forages are dependent upon the interaction of a number of factors, including soil, plant species, stage of maturity, yield, pasture management and climate. The objective of this study was to determine the adequacy of minerals for ruminants in forages collected from seven tropical countries
Lincoln\u27s Legacy of Leadership
Through this in-depth look at Abraham Lincoln, both before and during his presidency, we can learn through his leadership in times of confusion, war, and dissent. The set of chapters included in this volume are based on papers that constituted part of the 2008-2009 Jepson Leadership Forum at the Jepson School of Leadership Studies at the University of Richmond. The chapters consider Lincoln’s intellectual, moral, political, and military leadership. The authors include the world’s foremost Lincoln scholars, including Pulitzer Prize winner Daniel Walker Howe, and Lincoln Prize winners Richard Carwardine and Douglas Wilson.https://scholarship.richmond.edu/bookshelf/1007/thumbnail.jp
Infrared Emission from the Radio Supernebula in NGC 5253: A Proto-Globular Cluster?
Hidden from optical view in the starburst region of the dwarf galaxy NGC 5253
lies an intense radio source with an unusual spectrum which could be
interpreted variously as nebular gas ionized by a young stellar cluster or
nonthermal emission from a radio supernova or an AGN. We have obtained 11.7 and
18.7 micron images of this region at the Keck Telescope and find that it is an
extremely strong mid-infrared emitter. The infrared to radio flux ratio rules
out a supernova and is consistent with an HII region excited by a dense cluster
of young stars. This "super nebula" provides at least 15% of the total
bolometric luminosity of the galaxy. Its excitation requires 10^5-10^6 stars,
giving it the total mass and size (1-2 pc diameter) of a globular cluster.
However, its high obscuration, small size, and high gas density all argue that
it is very young, no more than a few hundred thousand years old. This may be
the youngest globular cluster yet observed.Comment: 6 pages, 2 color figures, Submitted to the ApJL, Revised 4/6/01 based
on referee's comment
Soil Aggregate Dynamics, Particulate Organic Matter and Phosphate under Dryland and Irrigated Pasture
Soil aggregate formation and turnover affects the rate of occlusion or release of soil organic matter and therefore the availability for mineralisation or stabilisation of soil carbon (C) and phosphorus (P). Furthermore, differences in soil type, management and the quantity and quality of organic inputs can affect aggregate turnover rates (Six et al., 2000). Under pastoral farming the ratio of coarse particulate organic matter (inter-POM) inside macroaggregates but outside microaggregates to fine POM (intra-POM) within microaggregates may provide an indication of physical processes influencing mineralisation and stabilisation of soil C and organic P (Po). Our aim was to determine the coarse and fine POM and associated C and P contents in water stable macro and microaggregates under long term irrigated and dryland pasture grazed by sheep
GENETIC ASPECTS OF BEEF PRODUCTION AMONG HOLSTEIN-FRIESIANS PEDIGREE SELECTED FOR MILK PRODUCTION
To explore the potential of cattle to produce both milk and beef, the genetic aspects of beef production among Holstein-Friesian bulls pedigree selected for milk were studied. The data included growth records of 504 bulls (DPT) by 120 sires (SPT) pedigree selected for progeny testing by American Breeders Service, 1964 to 1971. DPT bulls with proofs had an average predicted difference for milk (PMD) of +180 kilograms. The daughter average was 7,273 kg per lactation under varying herd conditions. Sires accounted for 10% of the variation in average daily gain (ADG), 10% in daily gain per 100 kg body weight (DG/100) and 16% in body weight, indicating substantial genetic variability in beef traits. Sire variance components for beef traits varied with age. There were wide ranges in estimated breeding value (EBV) and estimated transmitting ability (ETA) for beef traits among DPT and SPT bulls, respectively. Ranking EBV among DPT bulls and ETA among SPT bulls for beef traits and selecting the top 10% and 20%, respectively, showed high selection differentials, empirically reflecting the potential for genetic improvement from selection
Complexity-based learning and teaching: a case study in higher education
This paper presents a learning and teaching strategy based on complexity science and explores its impacts on a higher education game design course. The strategy aimed at generating conditions fostering individual and collective learning in educational complex adaptive systems, and led the design of the course through an iterative and adaptive process informed by evidence emerging from course dynamics. The data collected indicate that collaboration was initially challenging for students, but collective learning emerged as the course developed, positively affecting individual and team performance. Even though challenged, students felt highly motivated and enjoyed working on course activities. Their perception of progress and expertise were always high, and the academic performance was on average very good. The strategy fostered collaboration and allowed students and tutors to deal with complex situations requiring adaptation
Potential of Deshi Cattle of India for Dairy Production
There were 1,405 lactation records of 336 cows at the Central Livestock Research- cum-Breeding Station, Haringhata, India from 1958 to 1968 used to estimate the potential dairy merit of Deshi cattle. This breed is native to northeast India and one of the smallest breeds in India (mature females 200 kg and males 250 kg). Averages and standard deviations for milk yield (exclusive of that suckled), age of first calving, calving interval, lactation length, days open, and days dry were 412 ± 178 kg, 44.5 ± 6.8 months, 419 ± 90 days, 264 ± 81 days, 135 ± 86 days, and 139 ± 80 days. Mortality, culling, and retention rates for females from birth to first calving were 24, 27, and 49%. Lactation number, season of calving, and death of calf early in lactation had significant effects on milk yield. Repeatabilities of milk yield, lactation length, calving interval, dry period, and days open were .42, .19, .21, .03, and .23 with corresponding heritabilities .64, .19, .09, .19, and .27. Heritability for age of first calving was .84. Confounding by some environmental effects probably biased heritability estimates upward. Potential genetic improvement of milk yield by mass selection was estimated at .8% per year. Contemporary Jersey X Deshi crosses exceeded Deshi for milk yield, age of first calving, lactation length, calving interval, and days open by +923 kg, -15 months, +41, -84, and -96 days. At least one generation of crossing with European breeds is recommended over mass selection of Deshi
Organizational Efficacy of Small and Medium-Sized Suppliers: The Role of Information Quality and Continuous Quality Improvement
The role of information quality and continuous quality improvement was analyzed in regards to the organizational efficacy of small and medium-sized suppliers. It was anticipated that both variables would have positive relationships with organizational efficacy. Results supported these hypotheses and demonstrate the importance of firms controlling the flow of quality information and emphasizing continuous quality improvement in order to strengthen organizational efficacy. Given the significant impact of efficacy on individual and group performance and the relationships confirmed as part of the current study, future research is called for such that we might better understand the qualities that characterize the successful supply chain relationships for SMEs
Reproductive efficiency and viability in two \u3ci\u3eBos indicus \u3c/i\u3eand two \u3ci\u3eBos taurus \u3c/i\u3e breeds in the tropics of India and Colombia
Records from two herds in India and two in Columbia representing respectively two breeds of Bos indicus (Hariana and Deshi) and two Bos taurus breeds—Blanco Orejinegro (BON) and Costeño Con Cuernos (CCC) were evaluated for breeding efficiency and viability. Average age at first calving was 52.1, 46.3, 39.5 and 40.7 months for Hariana, Deshi, CCC and BON. Season of birth did not influence age at calving. Ranking for calving interval was similar, average 479, 418, 396 and 382 days with season effects significant (P\u3c.05) for only Deshi. BON and CCC had fewer days open but much shorter lactation periods, average 73 and 157, thus days carried calf in lactation were similar for all breeds. Percent of time dry per calving interval was high for all breeds, 44.2, 36.7, 64.1 and 81.0 for Hariana, Deshi, BON and CCC. Average annual mortality of females by 12 months of age was 23.6% for Hariana, 17.0% Deshi and 27.0% BON. In the same herds 46.4%, 51.1% and 49.0% of females born alive lived to first calving and annual losses among cows were 18.0%, 17.0%, and 21.0%; therefore, affording little opportunity for selection among females. Temperament, as determined by response to the milking process with and without the calf present, showed all the breeds were similar in this respect. Environmental effects were most important for all traits but genetic differences were indicated for age at first calving and milk yield. On a theoretical basis little gain could be expected in net dairy merit from crosses between the Columbian and Indian breeds
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