Influence of incrementally substituting dietary soya bean meal for rapeseed meal on nutrient digestibility, nitrogen excretion, growth performance and ammonia emissions from growing-finishing pigs.

摘要

A completely randomized design experiment was performed to examine the effects of replacing different levels of soybean meal (SBM) with rapeseed meal (RSM) on the growth performance, carcass characteristics, apparent nutrient digestibility, N balance and manure ammonia emissions of growing-finishing swine. Swine (n = 336; mean live wt. 42.1 kg) were assigned to 1 of 4 dietary treatments containing (per kg): 210 g SBM; 140 g SBM and 70 g RSM; 70 g SBM and 140 g RSM; and 210 g RSM. All diets were formulated on an ileal digestible amino acid, net energy and available phosphorus basis. There were no significant treatment effects upon average daily gain, feed intake, feed conversion ratio and carcass characteristics. There was a linear decrease in gross energy digestibility (P < 0.01) as RSM increased at the expense of SBM in the diet. In addition, linear decreases in urinary N excretion (P < 0.01), N digestibility (P < 0.05), total N excretion (P < 0.05) and N retention (P < 0.05) were observed with increasing levels of RSM. Dietary treatment had no effect upon manure ammonia emissions. Results indicate that RSM may be used as a direct replacement for SBM with no associated depression in performance, when formulated on an ileal digestible amino acid and net energy basis. Consumption of diets containing incremental levels of RSM linearly decreased urinary N and total N excretion, reflecting the associated decrease in crude protein concn.