Effect of Different Levels of Speed Feed Sorghum Silage on Productive Performance, Milk Composition and Milk Fatty Acids in Lactating Cows

Corn silage is becoming one of the main popular feeds for dairy farms, but due to high water demand, sustainability of corn silage production is coming to be constraint. Sorghum has been considering alternative silage crop with significant forage production and lower water requirement. Therefore, this experiment was plant to replace corn silage by sorghum silage in the diet of dairy cows.

Sorghum (Speed feed Var.) and corn were planted (two hectares for each) and the forge obtained was ensiled separately. Four diets (treatments) contained 24 percent silage (DM basis) formulated in which corn silage replaced with 0.00, 33, 66 and 100% with sorghum silage. 32 lactating cows (average 44 days in milk) were divided into two blocks with average daily milk of 34.11 and 28.20 kg and then the cows of each block allocated to four experimental diets. Nutritive values of the diets adjusted to the requirements of cows in each block.

Average daily dry matter intake was not statistically affected by the experimental diets but the cows in high milk yield blocks consumed higher dry matter (p<0.05). The fresh milk and 3.5FCM yield did not affected by the treatments but the average milk yield was different between the blocks throughout the experiment. Feed efficiency based on the kg of milk yield per kg dry matter intake was not affected by the treatments and between the blocks as well. Milk compositions including fat, protein, lactose, solid non fat, total solid and milk urea nitrogen were not affected by the treatments but total saturated fatty acids were decreased by inclusion of sorghum silage in the diets (p<0.05).

In general, results showed that the corn silage could be replaced by sorghum silage (speed feed var.) in the diets of lactating cows (with daily milk yield about 30kg). However, due to the lower starch and lower energy content in sorghum silage than the corn silage, the diets should be supplemented with starch sources to compensate the energy balance, when use sorghum silage.