Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 28, 1998
Publication Date: N/A
Technical Abstract: Rumen fermentable starch from processed or high moisture grains has been shown to improve milk yield by lactating cows. Four Holstein cows (BW, 569 kg, SE 7; 160 DIM) were allotted to four dietary treatments in a 4 x 4 Latin square design. Diets were alfalfa-based TMRs with 37 to 43% corn (DM basis), formulated to be isocaloric using NEL values for dry corn and high moisture corn determined previously with the Beltsville calorimeters. Corn was included at different ratios of dry ground corn (DC) to high moisture ground corn (HMC): 100% DC, 60:40 DC:HMC, 40:60 DC:HMC, or 100% HMC (R1, R2, R3, R4, respectively, and order to be used). Diets averaged 44% DM, 14% CP, and 36% NDF. Cows were fed ad libitum twice daily. Periods were 21 d with 14 d for adaptation and 5d total excreta collection. There was a significant effect (cubic, P<.05) on intake of DM (23.0, 20.0, 22.6, 21.6 kg/d) as HMC increased in the diet. Dry matter digestibility did not differ (66.1, 65.3, 66.9, 67.3%), but there was a linear (P<.01) increase in starch digestibility (87.9, 89.5, 90.1, 95.2%). Effect of diet on milk yield (actual) was similar to that for DMI (cubic, P<.1) (28.7, 26.9, 28.3, 27.4 kg/d). There was a significant effect (cubic, P<.1) on milk protein yield (.95, .90, .96, .91 kg/d) as HMC increased in the diet, as well as yield of all other milk components. The inclusion of corn, as a mixture of 40:60 DC:HMC, in alfalfa-based diets optimized starch digestibility, intake, milk yield, and milk protein yield.