The invention discloses a 
feed additive with a release effect and capable of treating sow metritis. The 
feed additive is prepared from the following components: soybean pulp, corn, grape 
skin pomace, 
astilbe chinensis, herba leonuri, radix angelicae sinensis, cortex ilicis rotundae, ossa draconis, fructus 
ligustri lucidi, rhizoma atractylodis macrocephalae, 
herb of adnate elder, herba salviae chinensis, herba taraxaci, rhizoma zingiberis recens, fructus crataegi, 
pericarpium citri reticulatae, fructus jujubae, silkworm chrysalis, 
sodium alginate, 
chitosan, 
starch, 
magnesium stearate and 
sucrose ester. The preparation method comprises the following steps: material preparation, extraction of effective components of 
traditional Chinese medicine bulk drug, pelleting, tabletting and pelleting. The 
feed additive disclosed by the invention is capable of resisting 
bacteria, diminishing 
inflammation, activating 
blood circulation, removing 
blood stasis, draining 
toxin, expelling pus, invigorating 
spleen-
stomach and replenishing qi, and is capable of effectively treating the sow metritis; durable and slow in-vivo 
drug release can be realized, the 
blood concentration is stable, and the fluctuation is small, so that the 
dosing frequency is reduced, the concentration of effective 
drug components in blood is controlled so as to maintain the pharmacological function, the peak times of 
drug release are reduced, and certain protection is carried out on visceral organs of sows and piglets.