Thursday, March 14, 2019

Do antibiotic residues in milk effect dairy calves?

The three characteristic studied in this work were:
  1. growth
  2. ruminal fermentation
  3. microbial community
Calves were studied up to 35 days of age. Half of them receive antibiotic- free milk [FREE] while the other half received milk with antibiotics added to simulate residues [ANT].

No differences in:
(1) starter intake,
(2) body weight,
(3) withers height,
(4) body length,
(5)  heart girth, and
(6) average daily gain. 

In the rumen the ANT calves had a higher acetic acid concentration (probably tied to antibiotics changing the microbial profile). Certain papillae were longer in the ANT group compared to the FREE calves. 

There were very few effects on the overall microbial communities in the rumen.

So, until we get more information I am not going to worry too much about low levels of antibiotic residues in waste milk fed to calves.

Reference: Li, J.H. and Others, "Effect of antibiotic residues in milk on growth, ruminal fermentation, and microbial community of preweaning dairy calves." Journal of Dairy Science, 102:2298-2307

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