Effects Of Sieve Aperture And Post-conditioning Moisture On Production Power Consumption And Application In Extruded Soybean

This research aimed to study the effcets of sieve aperture and post-conditioning moisture on power consumption in extruded soybean processing, as well as its application effects. Firstly, we disclosed the impact exerted by sieve aperture and post-conditioning moisture on power consumption, output and product indexes of full-fat soybean, followed by detecting nutrient digestibility of extruded soybean via digestion experiment in vitro. Taking them into account, we evaluated and selected the optimum gradient of particle size or post-conditioning moisture. Moreover, effects of sieve aperture on growth performance, nutrient digestibility were further analyzed systematically. The main results were as followings:1. The experiment was conducted to study the effects of sieve aperture and post-conditioning moisture on production processing parameters and product indexes related for full-fat soybean. Sieve apertures including2.5mm,2.0mm,1.5mm, which crossed with post-conditioning moisture of14.5%,17.5%,20.5%to process. In addition to recording energy consumption and output, we analyzed nutritive indicators of extruded soybean, to identify the optimum gradient of sieve aperture or post-conditioning moisture. The result of this experiment indicated: sieve aperture has significant difference on particle size, power consumption and output (P<0.01). reduction of sieve aperture can increase power consumption and decrease output in milling and extrusion processing. Increased post-conditioning moisture resulted in increased energy consumption and reduced production for extrusion. It was likely that sieve aperture has no significantly difference on available lysine (Alys)(P>0.05), however, there were significant difference on trypsin inhibitor activity (TIA) and protein solubility (PS)(P<0.01). As sieve aperture increased, TIA and PS decreased. Post-conditioning moisture significantly affected the Alys of extruded soybean (P﹤0.01). Increasing post-conditioning moisture led to improving Alys, coupled with reducing TIA and PS. Interaction of sieve aperture and post-conditioning moisture has a remarkable effect on TIA and PS (P﹤0.01), without significantly difference on Alys (P>0.05). Conclusion: assuming that energy consumption can be relatively low and product indexes seemed satisfactory, gradient of sieve aperture with17.5%post-conditioning moisture was an acceptable alternative. 2. An experiment was conducted to study the effects of sieve aperture and post-conditioning moisture on digestibility (in vitro) of nutrients of extruded soybean. Nine groups of extruded soybean were hydrolysed in vitro by pepsase and trypsin, followed by determing dry matter (DM) and crude protein (CP) degistibility. Consequencely, we were enable to select optimum gradient of sieve aperture or post-conditioning moisture. The result of this experiment indicated:reduced sieve aperture and increased post-conditioning moisture significantly improved DM and CP digestibility (P﹤0.01). Conclusion: taking digestibility of DM, CP and production processing and product indexes of full fat soybean into consideration, the optimum gradient was sieve aperture2.5mm,2.0mm,1.5mm with post-conditioning moisture17.5%.3. A digestive and metabolic experiment was conducted to study the effects of sieve aperture of extruded soybean-based diet on digestion and metabolism of nutrients in growing pigs. According to single factor design, twenty Duroc×Landrace×Yorkshire castrated barrows with an average initial weight of (31.07±0.61) kg were randomly allocated into four treatments with five replicates, and each replicate contained one pig. Collection full excrements analysis method has been carried out and the experiment lasted for12d. The content of dry matter, energy and crude protein of feed and fecal, energy and nitrogen of urine were determined and analysed. The result of this experiment indicated: there were no significant (P>0.05) differences in digestibility of dry matter, net protein utilization (NPU) and digestibility of N among four treatments, but sieve aperture has significant difference on biological value (BV)(P﹤0.05); there were no significant (P﹥0.05) differences in energy intake, UE, ME among four treatments, but there were significant (P<0.05) differences on fecal energy (FE), digestible energy (DE),digestibility of DE among four treatments. Conclusion: the reduction of sieve aperture was no difference on digestibility of dry matter, and no greatly difference on parts of N and energy balance. It was better effect to digest and absorb of nutrients for2.0mm extruded soybean with three kinds of sieve aperture.4. A feeding experiment was conducted to study the effects of sieve aperture of extruded soybean-based diet on growth performance in piglets. Two hundred and twenty-four Duroc×Landrace×Yorkshire piglets were randomly allocated into four treatments with eight replicates, and each replicate contained seven piglets based on body weight and body condition. Feed diets were based on soybean meal and extruded soybean which was used the sieve aperture1.5mm,2.0mm,2.5mm to compare the effect of sieve aperture of extruded soybean-based diet on growth performance in piglets. The experiment lasted for19d. The result of this experiment indicated: there were no significant (P>0.05) differences in average daily gain (ADG) and final body weight among four treatments. No other significant effects were found in average daily feed intake (ADFI), feed conversion ratio (FCR) and diarrhea rate (P>0.05). Conclusion: In the actual production condition, there were no different effects of sieve aperture of1.5mm,2.0mm,2.5mm extruded soybean replaced soybean meal of growth performance in piglets, and taking processing cost into consideration, it was better to choose sieve aperture2.5mm to process.Conclusions can be drawn from results above: sieve aperture and post-conditioning moisture has impact on production processing and product indexes for full fat soybean to some degree. Sieve aperture2.0mm for extruded soybean was good for digestion and absorption relatively, but sieve aperture has no effect on production performance of piglets within a certain range (1.5～2.5mm). Taking cost into consideration within the range, it was better to choose sieve aperture2.5mm, post-conditioning moisture17.5%to the production and processing for extruded soybean.