Effects of feeding rice and the degree of starch gelatinisation of rice on nutrient digestibility and ileal morphology of young pigs
B Vicente, DG Valencia, MP Serrano, R Lazaro and GG Mateos.2009, British Journal of Nutrition, 101:1278–1281.
11-Jan-2011 (15 years 4 months 28 days ago)Heat processing of cereals increases starch gelatinisation, improving nutrient availability and pig performance. However, an excess of heat might increase the proportion of resistant starch, reducing nutrient digestibility and piglet growth. Therefore it was evaluated the influence of the main cereal of the diet and the degree of heat processing of rice on apparent ileal and total tract digestibility of nutrients and ileum morphology of pigs at 37 d of age.
A total of 28 piglets (7 per dietary treatment) were individually allocated. There was a control diet based on dried whey, fishmeal, soybean meal and 500 g/kg cooked and flaked maize and three extra diets in which the maize was substituted (w/w) by rice that is either raw, cooked or cooked and flaked. Control pigs were fed a complex diet with a degree of starch gelatinisation (SG) of 840 g/kg. Experimental groups received the same complex diet in which maize was substituted (w/w) by rice with three different degrees of SG; 110, 520 and 760 g/kg that corresponded to raw rice and cooked rice processed under two different set of conditions.
The digestibility of dietary components, except for nitrogen, was greater for the cooked rice – than for the raw rice – and the maize diet (P<0.001). Pigs fed cooked rice had higher villous height to crypt depth ratio (P<0.001) and greater percentage of zigzag-oriented villi and lesser percentage of tongue-oriented villi (P<0.01) than pigs fed other diets. Compared with feeding maize, feeding rice improved dietary component digestibility and ileal morphology in piglets. Mild cooking of rice (SG = 520 g/kg) enhanced diet digestibility and ileum morphology. However, processing the rice to increase SG to 760 g/kg did not increase nutrient digestibility further and in fact impaired ileal morphology.
A total of 28 piglets (7 per dietary treatment) were individually allocated. There was a control diet based on dried whey, fishmeal, soybean meal and 500 g/kg cooked and flaked maize and three extra diets in which the maize was substituted (w/w) by rice that is either raw, cooked or cooked and flaked. Control pigs were fed a complex diet with a degree of starch gelatinisation (SG) of 840 g/kg. Experimental groups received the same complex diet in which maize was substituted (w/w) by rice with three different degrees of SG; 110, 520 and 760 g/kg that corresponded to raw rice and cooked rice processed under two different set of conditions.
The digestibility of dietary components, except for nitrogen, was greater for the cooked rice – than for the raw rice – and the maize diet (P<0.001). Pigs fed cooked rice had higher villous height to crypt depth ratio (P<0.001) and greater percentage of zigzag-oriented villi and lesser percentage of tongue-oriented villi (P<0.01) than pigs fed other diets. Compared with feeding maize, feeding rice improved dietary component digestibility and ileal morphology in piglets. Mild cooking of rice (SG = 520 g/kg) enhanced diet digestibility and ileum morphology. However, processing the rice to increase SG to 760 g/kg did not increase nutrient digestibility further and in fact impaired ileal morphology.