Performance of Slow-Growing Male Muscovy Ducks Exposed to Different Dietary Levels of Quebracho Tannin

SIMPLE SUMMARY: Different inclusion levels of Quebracho tannin (QT) in the diet of growing male Muscovy ducks of a slow-growing type were explored under free-range conditions. As a result of the dietary treatments tested in this trial, the growth performance or the total blood proteins were not affected. By contrast, dietary QT did not lead birds to produce less moist excreta, as observed in other bird species, as a desirable aspect for intensively raised poultry. A marked improvement in carcass yield was observed as a desirable economic trait in the extensive slow-type duck farming system. ABSTRACT: The study of the nutritional effects of tannins is complex due to the large chemical diversity; consequently, in poultry nutrition the biological responses may vary greatly. The aim of the present study was to evaluate the effect of different levels of dietary Quebracho tannins (QT) on growth and production performance in slow-growing type Muscovy ducks. For this purpose, a 42-d trial was carried out on 126 male ducks (42-d old at start), fed on three levels of dietary QT inclusion in the diet (0% as control diet, vs. 1.5% vs. 2.5% on an as fed basis). Birds were reared under free-range conditions. A linear increase in feed intake as a function of QT inclusion in the diet was observed (p < 0.05). No difference as to final body weight, overall average daily weight gain (ADG) and total feed conversion ratio (FCR) in relation to dietary treatments was observed. Carcass yields were positively improved in QT birds (p < 0.05). No adverse responses were recorded in total blood protein and liver weight. Dietary QT might be safely used up by to 2.5% in 42- to 84-d aged male Muscovy ducks.