Influence of dietary rapeseed meal levels on growth performance, organ health and standardized ileal amino acid digestibility in meat ducks from 15 to 35 days of age
Moreover, nutrient value of RSM depends on the kind of seed, cultural environment, extraction and processing techniques (Korelesky, 1993), as well as the content of antinutritional factors (ANFs), such as glucosinolates and sinapine, which are the major limiting factors that cause change in the thyroid and liver tissues, and high dietary inclusion for long periods may affect growth performance and induce thyroid hypertrophy and hepatic lesions (Kermanshahi and Abbasi Pour, 2006; Luo et al., 2012; Mikulski et al., 2012). Other drawbacks of RSM are the high content of fibre and other dietary components that prevent amino acids (AA) from absorbing and digesting (Eklund et al., 2015). Apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of crude protein (CP) and AA in RSM for poultry and pig have been determined over the last few years (Rezvani et al., 2012; Kim et al., 2015). However, the experimental periods in these studies were short, where the treatment diets were fed for only 5 to 7 days without consideration of long‐term ANF deposition, which may have an effect on health of birds and may impair nutrient digestibility or availability. To our best knowledge, no reports are available on the effect of dietary RSM level on AID and SID of CP and AA in meat ducks. Therefore, the objectives of the current study were to determine the effects of dietary RSM levels on growth performance, organ health, AID and SID of AA and to establish the maximum limits of dietary RSM concentration based on growth performance in 15‐ to 35‐days meat ducks.