Dairy Science Department
BS in Dairy Science
Feeding individualized rations for lactating dairy cattle in the commercial herd based on dietary needs is a popular issue. This has been a debating topic since evolution of the Total Mixed Ration (TMR). Since dairymen were able to mix grain in a feed wagon and mix a specific dietary ration to meet the demand for an organized group, there has been an issue in which protocol cow pen grouping should take. Dairymen have always feed cattle based on if lactating or late in their gestation, nonlactating. With the evolution of the TMR dairymen are then allowed to go into more depth and detail in individualizing certain rations to meet specific dietary needs for lactating cows. Each cow has a required diet based on many different factors throughout her lactation. The debate is how these cattle should be grouped and fed to meet the requirements as a whole. A few of the groups under debate are fresh cows (first 60 days of lactation), High producing (usually early in lactation), First lactation and submissive cows, late lactation and older cows. Other systems of grouping are based on the cows reproduction, if the cow is open or pregnant. Dairymen have grouped cows based on their Body Condition as well. There are many advantages and disadvantages in grouping cows and separating TMRs, but the justification of this project is to provide substantial information leading to the greater advantage of feeding individualized rations for lactating dairy cattle. Grouping is a special problem because the manager neither controls nor is able to determine feed consumption by individual cows. To achieve maximum income above feed cost the rations should be consumed in large quantities, contain a high concentration of utilizable nutrients, contain sufficient fiber to avoid depressed milk fat percentage, and contain feed ingredients formulated on least cost. The advantages and limitations of feeding a single mix or feeding multiple mixes of feeds are discussed. Specifications for rations and sample ingredient mixes for various stages of lactation and yields of daily milk are presented. Much of my data collected will be from past study researches as well as interviews with current nutrients and dairymen currently practicing group feeding.