Dietary fish oil supplements depress milk fat yield and alter milk fatty acid composition in lactating cows fed grass silage-based diets

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Fatty Acid Nutrition and Milk Fat Depression

This information was presented the 2015 Herd Health and Nutrition Conference, organized by the PRO-DAIRY Program in the College of Agriculture and Life Sciences at Cornell University. Softcover copies of the entire conference proceedings may be purchased at http:// ansci.cornell.edu/dm/ or by calling (607) 255-4478.Milk fat concentration is variable and very responsive to many factors including genetics, season of the year, and physiological state, but is especially responsive to diet. Synthesis of milk fat is an energy demanding process, but also represents a significant portion of the economic and nutritional value of dairy products. First described over one and a half centuries ago, diet-induced milk fat depression (MFD) is characterized by a decrease in milk fat yield of up to 50% with no change in milk yield or yield of other milk components. MFD is classically observed in ruminants fed highly fermentable diets or diets high in plant oils. Varying levels of MFD are commonly experienced today in both intensively and extensively managed dairy herds, and this represents a level of milk fat production below the genetic potential of the cow. MFD is also a useful variable for evaluating herd management; in many cases onset of diet-induced MFD is an indication of modified ruminal fermentation and in more pronounced cases this can be associated with ruminal acidosis and reduced efficiency. Therefore, maintaining optimal milk fat synthesis has value beyond the milk fat sold. Although we know extensively the cause of MFD we continue to experience MFD because of the high-energy requirements of cows and the desire to maintain optimal milk production. Numerous dietary factors commonly interact to cause MFD making prediction difficult. Recently we have investigated the time course of induction and recovery of MFD that provides insight into identifying causative factors and setting expectations for correction of MFD

New Insights in Milk Fat Research and Reviewing Our Progress

Presented during 2020 Virtual Cornell Nutrition ConferenceSteady progress has been made in understanding the regulation of milk fat synthesis since the discovery of bioactive CLA isomers 20 years ago. Recent understanding of the nutritional and non-nutritional factors that have practical implications in milk fat production will be discussed.Department of Animal Scienc

Impact of Daily and Seasonal Rhythms in Maximizing Milk Production

Presented at 2020 Virtual Cornell Nutrition ConferenceThere are seasonal patterns to milk and milk composition and daily patterns of intake and milk synthesis. These rhythms are important for accurately assessing herd production and provide the opportunity to increase milk and milk component yield through simple management interventions.Department of Animal Scienc