Effects of biogenic amines on growth and the incidence of proventricular lesions in broiler chickens

Biogenic amines have been implicated in a malabsorption syndrome characteri zed by decreases in feed efficiency and enlargement of the proventriculus. Two studies were conducted to determine the effects of two common biogenic amines, histamine (HIS) and cadaverine (CAD), on broiler growth and the inc idence of pathologies associated with proventriculitis. In the first experi ment, broiler chicks were fed diets containing 0, 0.01, 0.05, 0.1, and 0.2% HIS, and in the second experiment chicks were fed diets containing 0, 0.1, and 0.2% HIS, 0.1% CAD, or a combination of 0.1% HIS and 0.1% CAD. Histami ne at 0.1 and 0.2% or the combination of HIS and CAD (0.1% each) reduced bo dy weight and feed conversion at 21 d of age. Histamine (0.2%) or the combi nation of 0.1% HIS and 0.1% CAD increased the circumference of the gastric isthmus 14 and 16%, respectively, and the relative weight of the proventric ulus by 21 and 36%, respectively. Histamine and CAD increased the total num ber, incidence, and severity of gizzard erosion and proventricular ulcers ( plaques), and decreased the prominence of gastric papillae by 9 to 108%, de pending on the lesion and level of biogenic amine. Dietary HIS (0.2%) incre ased putrescine by 91%, and spermidine by 41% in proventriculus, and dietar y CAD increased tissue CAD to detectable levels. Analysis of 49 commerciall y available, animal by-product feedstuffs suggests that if biogenic amines were the singular cause of proventriculitis, the current industry levels of dietary animal protein (5 to 10%) would not compromise growth performance.