Effects of variety, soil type and nitrogen fertilizer supply on the nutritive value of barley for growing pigs

Abstract

The effects of variety, soil type and nitrogen (N) fertilizer supply on the nutritive value of barley were studied with chemical analysis, in vitro digestibility and a growth experiment on 240 growing/finishing pigs (live-weight 25-95 kg). Twelve barley batches were formed from three varieties (two-rowed Kustaa and six-rowed Arra and Pokko) grown on mould or clay soil and fertilized with either a low or normal level of N (43 or 71 kg N/ha to mould soil and 76.5 or 110 kg N/ha to clay soil). In the growth experiment all the diets contained similar amounts of barley and soya bean meal (845/120 g/kg). Variety Arra contained 21 g/kg more CP than did Pokko or Kustaa. The N fertilizer supply slightly increased the CP content of the barley samples (133 vs. 141 g/kg) but decreased the amount of lysine in the protein (31 vs. 29 g/ 160g N). Regression equation showed that CP and β-glucan were positively and neutral detergen fibre content negatively related to the in vitro digestibility of N in barley samples. The content of CP and the in vitro digestibilities of dry matter and N were highest in var. Arra. The daily gain and feed conversion ratio (FCR) of the pigs on Arra-based diets was better than that of those on Kustaa or Pokko (P