Nutritional value of seaweed ( Ulva rigida) for poultry

Abstract

A study was conducted to establish the nutritive value (true metabolizable energy (TMEn), apparent metabolizable energy (AMEn) and chick performance) of seaweed ( Ulva rigida) in poultry diets. The proximate composition (kg −1 DM) of seaweed was: 33 g nitrogen, 17 g ether extract, 47 g crude fibre, 312 g NDF, 153 g ADF, 13 g pentosans and 228 g ash. The TMEn value of U. rigida, determined after tube-feeding, was 5.7 MJ kg −1 and 4.3 MJ kg −1 DM for chicks and cockerels ( P < 0.05), respectively; the AMEn value, determined by regression using titanium dioxide as an indigestible dietary marker in a chick growth trial fed on diets containing (kg −1) 0, 100, 200 and 300 g seaweed, was 2.9 MJ kg −1 DM. As the content of seaweed was increased, feed intake and growth rate decreased ( P < 0.05). The results of this study showed that crude U. rigida is not a suitable ingredient for poultry diets, at least at inclusion rates of 100 g kg −1 or higher; however, seaweed did not have an antinutritive effect, because the addition of seaweed did not modify the TMEn of the rest of the diet (standard diet or glucose).