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News Article

Clay supplementation in dairy cattle improves feedstuff degradability 

Grass hay, wet brewer's grains, soyabean meal degradability tested with and without addition of clay 

Clay is often used as a feed supplement to reduce symptoms of aflatoxin and subacute ruminal acidosis (SARA) in lactating cows. A new study published in Animal Feed Science and Technology demonstrates the ability of clay to also improve feed degradability.

According to Phil Cardoso, study co-author and associate professor in the Department of Animal Sciences at the University of Illinois, farmers had concerns about the addition of clay having an effect on the feedstuffs used in cattle diets. The study findings confirm that the clay does alter the manner in which the feedstuffs are degraded.

Cardoso and his team tested the degradability of six feedstuffs - dried alfalfa hay, grass hay, wet brewer's grains, ground corn, corn silage, and soybean meal – without and with added clay, 1%, or 2% of dietary dry matter.

Feedstuffs were placed into mesh bags and inserted directly into the rumen through a cannula or fistula. Bags were then drawn out at various time intervals (two hours to four days) and analyzed.

According to Cardoso, differences were observed in feedstuff degradation over time. When clay was added to grass hay at 2% of dietary dry matter, digestibility and usage of fat in that material was maximized. There was no decrease in degradability of the other feedstuffs either, with Cardoso recommending clay be added at 1 to 2% of dietary dry matter to maximize its benefits.

Previous research by Cardoso has shown that various types of clay are effective in removing aflatoxins by binding to them and eventually excreted from the cow's body. A 2018 study by Cardoso's team showed that aluminosilicate clay also improved immune function and reduced liver inflammation during an aflatoxin challenge in cows.

Improvements of in situ degradability of grass hay, wet brewer's grains, and soybean meal with addition of clay in the diet of Holstein cows. Animal Feed Science and Technology (2020) 259:114331, DOI: 10.1016/j.anifeedsci.2019.114331

Article details

  • Date
  • 28 November 2019
  • Source
  • University of Illinois ACES
  • Subject(s)
  • Animal nutrition