Dairy Science Department
BS in Dairy Science
The objective of this study was to determine if supplementing Brown Midrib Corn Silage into a high cow feed ration could improve digestibility in the rumen, add savings into the feed ration, and improve milk production. Beginning in June of 2012 two hundred high producing Holstein cows were selected from Johnny Mendonca & Sons Dairy in Tulare, Ca to estimate the difference between feeding Conventional Corn Silage compared to Brown Midrib Corn Silage. This test trial was conducted over the span of 4 months and was hypothesized by the author. To achieve this, the author conducted three analyses to determine if there was a significant difference between the two corn silages. First, in vitro digestibility tests were taken to examine the difference in digestibility between the two corn silages. After 30 hours of in vitro testing, digestibility was markedly higher in the Brown Midrib Corn Silage (69%) when compared with the conventional corn silage (52%). This concluded a difference of 17% digestibility between the two corn silages. Next, two separate rations were developed and fed to two separate testing groups, which both contained one hundred high producing milking cows. The first group was fed a ration that implemented conventional corn silage while the second ration and testing group implemented brown midrib corn silage. A ration containing the brown midrib corn silage was conceived to utilize the brown midrib corn silage based on its digestibility features by the dairy’s nutritionist. The distinct digestibility features of the Brown Midrib Corn Silage led to a reduced amount of needed grain corn. The second testing group and feed ration required three pounds less grain corn, creating a savings in cost. Over a course of a year this resulted in a potential savings of $ 16,917.75. To determine the difference in milk production between the two testing pens, milk composition tests were obtained during a course of three months. At peak milk production the Conventional Corn Silage group produced 82 lbs. per cow per day whereas the Brown Midrib Corn Silage group produced 87 lbs per cow per day.