Determination of digestibility, degradability and energy of diets containing different levels of wheat bran in early lactating Holstein cows

In the first experiment, 12 Holstein cows in second lactation with an average of 65 days in milk on a balanced change-over design with four dietary levels of 0, 10, 20 and 30 percent wheat bran (on the basis of dry matter) have been studied. Four periods of 28 days and three replications in each period to measure nutrient digestibility, total digestible nutrients (TDN) and predicted net energy for lactation (NEL) from TDN and dissociation energy data for different activities considered. Digestibility of dry matter, organic matter, neutral detergent fiber and crude protein of the diets containing both barley and wheat bran were higher compared to the other diets (p<0.05). Increased levels of wheat bran in the diets decreased digestibility of all nutrients. Similarly calculated TDN and NEL were also significantly decreased (P<0.05). In the second experiment, three male cattle Talysh in a completely randomized design with four levels of dietary treatments containing 0, 10, 20 and 30% wheat bran (DM basis), three repeated measurements at 9 different time for determining degradability of DM, OM, CP, NDF was used. This experiment showed that increasing levels of wheat bran non-significantly increase nutrient degradability of the experimental diets (P>0.05).