Juan A. Javierre. DVM-PDO-MBA

Trypsin and chymotrypsin inhibitors will also inhibit the activity of trypsin-like proteases, such as serine proteases, see Morita (1996) Journal of Biochemistry, 119(4), 711–718. In that respect, you will probably fare better with aspartic proteaes, which are resistant to trypsin (Kunitz) and trypsin and chymotrypsin (Bowman-Birk) inhibitors.

Thre is an interesting review on the topic of antoibiotic replacement, albeit in swine: Tacker P. A. (2013). Alternatives to antibiotics as growth promoters for use in swine production: a review. Journal of Animal Science and Biotechnology, 4:35 (open access). I cite his conclusion verbatim: "Clearly, a long and growing list of compounds exist which have been tested for their ability to replace a ...

You may wish checking a very recent paper published in Poultry Science, Poult. Sci., (2014) 93:132-137 on the effect of essential oils and plant extracts on broiler production. Regards