A) Keep feed costs down by feeding less of expensive protein sources.
B) Enhance production by feeding more fermentable carbohydrate.
A trial with 70 cows was conducted at the University of Wisconsin with several objectives in mind; one of them was to improve the N efficiency by feeding an AA balanced ration. All cows were fed a diet containing 60% forage on a dry matter basis (58% corn silage - 42% alfalfa silage); the diet of one group of 15 cows was supplemented with ground shelled corn, high moisture shell corn, soybean meal, dried molasses, Energy Booster, a pre-mix with minerals and vitamins and 40 grams of dry MetaSmart®. Another group of 15 cows was fed a higher protein ration where corn distillers and Soyplus was also included in the formulation. The diet with MetaSmart was formulated according to NRC guidelines to provide:
A) A lower supply of MP (2450 grams vs. 2590 grams), reducing the CP concentration (15.7% vs. 16.8%) of the ration.
B) A higher NFC concentration (47.0% vs. 43.6%).
The cows fed MetaSmart produced 2 lbs extra milk with .08% extra fat and .14% extra protein, an increase of 3.5 extra lbs in Energy Corrected Milk (ECM). In addition, the cows fed MetaSmart had lower MUN, PUN and higher N efficiency.
a,b: Values with different superscript in the column are different (P < 0.05)
The results from this research show that by AA balancing rations using MetaSmart, MP supply can be reduced, improving N efficiency and still enhance ECM production.
1Effect of feeding different sources of rumen-protected methionine on milk production and N-utilization in lactating dairy cows Chen et al., 2011 - J. Dairy Sci. 94:1978–1988