0.5 ml serum
Seven animals per feeding group should be tested when investigating herd problems. Typically this would be seven "fresh" or seven "close-up" cows. Samples should be taken just before fresh feed is offered (especially for cattle on component-fed rations. For cattle receiving TMR diets, timing is less important). Please include animal ID, age, species and lactation stage for each animal. Ship overnight and avoid weekend arrival. Excitement has an important influence on serum NEFA concentrations. Animals should be kept as calm as possible during blood collection. Avoid situations in which animals are shipped or herded through unfamiliar surroundings prior to sampling as these activities will result in elevated serum NEFA concentrations.