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Full-Text Articles in Dairy Science
Effects Of Feeding Rumen-Degradable Valine On Milk Production In Late-Lactating Dairy Cows, Kayla Hultquist, David Casper
Effects Of Feeding Rumen-Degradable Valine On Milk Production In Late-Lactating Dairy Cows, Kayla Hultquist, David Casper
David Casper
The study objective was to determine if feeding the rumen-degradable AA Val can increase milk production comparable to recombinant bovine somatotropin (bST). Eight multiparous late-lactating (255 ± 26.4 d in milk) Holstein dairy cows were blocked by milk yield (34.1 ± 8.25 kg/d) and randomly assigned to 1 of 4 treatments in a replicated 4 × 4 Latin square design with 21-d periods (7 d for dietary adaptation and 14 d for data collection). Treatments were control (CON), a single injection of recombinant bST (rbST), and Val fed at 40 (V40) and 80 g/d (V80). Cows were fed a total …
Development Of Mathematical Models To Predict Volume And Nutrient Composition Of Fresh Manure From Lactating Holstein Cows, J.A.D. Ranga Niroshan Appuhamy, L.E. Moraes, L.E. Moraes, C. Wagner-Riddle, David Casper, J. France, E. Kebreab
Development Of Mathematical Models To Predict Volume And Nutrient Composition Of Fresh Manure From Lactating Holstein Cows, J.A.D. Ranga Niroshan Appuhamy, L.E. Moraes, L.E. Moraes, C. Wagner-Riddle, David Casper, J. France, E. Kebreab
David Casper
Organic compounds in dairy manure undergo a series of reactions producing pollutants such as ammonia and methane. Because various organic compounds have different reaction rates, the emissions could be accurately determined if amounts and concentrations of individual nutrients in manure are known. A set of empirical models were developed for predicting faecal and urinary water, carbon (C), nitrogen (N), acid detergent fibre and neutral detergent fibre output (kg/day) from lactating Holstein cows. Dietary nutrient contents, milk yield and composition, bodyweight, age and days in milk were used with or without dry matter intake (DMI) as potential predictor variables. Multi-collinearity, goodness …