Attempts have been made to increase nutrient availability for milk production by increasing feed intake, optimizing ruminal fermentation, and supplementing nutrients to the diet that will escape ruminal degradation. Energy and N are the nutritional factors that most often limit microbial growth and milk production. Ruminal fermentation and flow of microbial and dietary protein to the small intestine are affected by feed intake and by the amount and source of energy and protein in the diet. Feeding protein and carbohydrate that are not degraded in the rumen increases the quantity of dietary protein that passes to the small intestine but may decrease the quantity of microbial protein that is synthesized in the rumen. This often results in only small differences in the total NAN that passes to the small intestine. Because microbial protein supplies a large quantity of total AA that passes to the small intestine, differences in passage of individual AA often are only slight. Additional research with cows consuming large amounts of feed are needed to identify combinations of feed ingredients that synchronize availabilities of energy and N for optimizing ruminal digestion, microbial protein synthesis, nutrient flow to the small intestine, and milk production and composition.

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Understanding human mobility is crucial for a broad range of applications from disease prediction to communication networks. Most efforts on studying human mobility have so far used private and low resolution data, such as call data records. Here, we propose Twitter as a proxy for human mobility, as it relies on publicly available data and provides high resolution positioning when users opt to geotag their tweets with their current location. We analyse a Twitter dataset with more than six million geotagged tweets posted in Australia, and we demonstrate that Twitter can be a reliable source for studying human mobility patterns. Our analysis shows that geotagged tweets can capture rich features of human mobility, such as the diversity of movement orbits among individuals and of movements within and between cities. We also find that short- and long-distance movers both spend most of their time in large metropolitan areas, in contrast with intermediate-distance movers’ movements, reflecting the impact of different modes of travel. Our study provides solid evidence that Twitter can indeed be a useful proxy for tracking and predicting human movement.

ObjectiveResearch studies show that social media may be valuable tools in the disease surveillance toolkit used for improving public health professionals’ ability to detect disease outbreaks faster than traditional methods and to enhance outbreak response. A social media work group, consisting of surveillance practitioners, academic researchers, and other subject matter experts convened by the International Society for Disease Surveillance, conducted a systematic primary literature review using the PRISMA framework to identify research, published through February 2013, answering either of the following questions:Can social media be integrated into disease surveillance practice and outbreak management to support and improve public health?Can social media be used to effectively target populations, specifically vulnerable populations, to test an intervention and interact with a community to improve health outcomes?Examples of social media included are Facebook, MySpace, microblogs (e.g., Twitter), blogs, and discussion forums. For Question 1, 33 manuscripts were identified, starting in 2009 with topics on Influenza-like Illnesses (n = 15), Infectious Diseases (n = 6), Non-infectious Diseases (n = 4), Medication and Vaccines (n = 3), and Other (n = 5). For Question 2, 32 manuscripts were identified, the first in 2000 with topics on Health Risk Behaviors (n = 10), Infectious Diseases (n = 3), Non-infectious Diseases (n = 9), and Other (n = 10).ConclusionsThe literature on the use of social media to support public health practice has identified many gaps and biases in current knowledge. Despite the potential for success identified in exploratory studies, there are limited studies on interventions and little use of social media in practice. However, information gleaned from the articles demonstrates the effectiveness of social media in supporting and improving public health and in identifying target populations for intervention. A primary recommendation resulting from the review is to identify opportunities that enable public health professionals to integrate social media analytics into disease surveillance and outbreak management practice.

Five Holstein cows were used in a 5 x 5 Latin square design and fed diets containing five different ratios of starch from ground shelled corn and steam-rolled barley. The DMI decreased and both the proportions of OM and starch digested in the rumen increased as barley starch increased in the diet. Corn and barley starches fed in a ratio of 75:25 maximized the proportions of ADF and NDF digested in the rumen. Replacement of 25% of the corn starch with barley starch resulted in the largest increase in the molar percentage of propionate and the largest decrease in the molar percentage of acetate in ruminal fluid. Passage of NAN to the duodenum was not affected by treatment; however, the percentage of nonammonia nonmicrobial N in NAN decreased as barley starch increased. Passage of AA to the duodenum was largest when corn and barley starches were fed in ratios of 100: 0 and 0:100 because of the influence of DMI and microbial protein synthesis. Production of Milk, CP, and SNF was similar when cows were fed diets containing corn and barley starches in ratios of 100:0, 75:25, and 50:50 but was decreased when the ratios were 25:75 and 0:100. Increased production responses of cows when diets contained larger amounts of starch from ground shelled corn were probably due to increased DMI.