Effect Of Different Starch Gelatinization Degree On Quality Of Pellet Feed And Growth Performance Of Weaned Piglets

In recent years,with the continuous development of intensive aquaculture and animal nutrition research,the early weaning feed nutrition and processing of piglets has received extensive attention.Weaning of piglets is one of the most important aspects of aquaculture production.Early weaning is beneficial to increase the productivity of sows,reduce the chances of piglets,and increase the survival rate and slaughter rate of piglets.However,due to the physiological characteristics of piglets such as incomplete development of digestive system,insufficient secretion of digestive enzymes and gastric acid,it is required that piglet feed should have low anti-nutritional factors,good palatability and high starch gelatinization on the premise of reasonable dietary formulation.Improving the gelatinization degree of feed is the key to meet the above requirements.At present,there is no definite conclusion about the gelatinization degree in the production of piglet feed.On the basis of satisfying the growth performance of piglets,determining the appropriate gelatinization degree,avoiding excessive processing and reducing processing costs are the focus of attention of enterprises at present.Two processing techniques were used to study the effects of gelatinization on the processing quality and growth performance of piglet feed.The main results are as follows:(1)Effects of expanded corn proportions on pellet feed quality and growth performance of weaned piglets.This study was conducted to evaluate the effects of different expanded corn additive proportions(0%,25%,50%,75%,100%)on the pellet feed processing quality and its effects on growth performance,nutrient apparent digestibility,blood biochemical indexes of weaned piglets.The results showed as follows:(1)In the feed processing quality: with increasing proportions of extruded corn,the particle hardness of pellet feed,PDI,starch gelatinization degree increased and brittleness decreased.Hardness increased from 22.26 N to 52.34 N,PDI increased from 93.84% to 97.21%,starch gelatinization increased from 37.72% to 85.96%..(2)The growth performance of weaned piglets: in early period,FCR was significantly higher than other groups(P <0.05);in later and full period,there was no significant difference between the groups at growth performance of weaned piglets.(3)In the nutrient apparent digestibility of weaned piglets: there was significant difference between the groups at dry matter apparent utilization and crude protein apparent utilization,the dry matter and protein apparent utilization in the expanded corn groups were significantly higher than the control group(P<0.05).(4)In the blood biochemical indexes of weaned piglets: the expanded corn treatment was higher than 0% group.Considering the influence of the proportions of expanded corn on the particle hardness,the growth performance of weaned piglets and the processing cost,it is suggested that the proportions of expanded corn in the diet of weaned piglets was 25% of the total amount of corn under the conditions of secondary.(2)Effect of different starch gelatinization degree of extrusion bulk raw materials on pellet feed quality and growth performance of piglets1)Effect of Extrusion Technology on starch gelatinization degree of Big Material.This study was conducted to the influence of extrusion process parameters,such as temperature,feed rate and number of template openings,on the expansion quality of bulk raw materials in diet and finds out the correlation between starch gelatinization degree and RVA was analyzed.The results showed as follows: With the gradual increase of feeding speed and number of template openings,the degree of gelatinization of feed gradually decreases,and the puffing effect of feed decreases.With the gradual increase of quenching and tempering temperature within the range of test temperature,the degree of feed gelatinization Although the change was not significant(P>0.05),but 90 °C was slightly higher than 80 oC,and the puffing effect of feed did not change significantly.2)Effect of different starch gelatinization degree of bulk raw materials on quality of Low Temperature Granulated Pellet Feed.This study was conducted to the effect of different starch gelatinization degree of bulk raw materials on the processing quality of pellet feed quality in weaned piglets under different low-temperature granulation parameters.The results showed as follows: the gelatinization degree of 87%,80% and 73% was no significant difference in the percentage of shaped pellets,PDI and hardness between groups(P > 0.05).The gelatinization degree was too high(92% of starch gelatinization degree),percentage of shaped pellets,PDI and hardness decreased.;The lengthdiameter ratio of ring die 5:1 group PDI,percentage of shaped pellets,hardness is significantly higher than 3:1 group(P<0.05),crispness is lower than 3:1 group;percentage of shaped pellets the conditioning time 40 s group were significantly higher than 80s(P<0.05),the effect of PDI,hardness,crispness was not significant(P >0.05).3)Effect of different starch gelatinization degree on growth performance of piglets.This study was conducted to the effects of four starch gelatinization degree(93%、89%、83%、75%)on the apparent digestibility,and growth performance and blood biochemical parameters of weaned piglets.The results showed as follows:(1)The growth performance of weaned piglets: there was no significant difference between the groups at the growth performance of weaned piglets.the group with 75% gelatinization degree of large materials had the best growth performance.(3)In the nutrient apparent digestibility of weaned piglets: Piglet dry matter apparent utilization and crude protein apparent utilizatio 83% group significantly higher than the 93%group(P<0.05).(4)In the blood biochemical indexes of weaned piglets: There were no significant differences in blood biochemical parameters between the groups(P>0.05),The total protein increased with the decrease of starch gelatinization degree.Considering the influence of starch gelatinization degree of the growth performance of the weaned piglets and the processing cost,it is recommended that the effect is best when the gelatinization degree is 75%.According to the results of the experiment under the two conditions,the gelatinization degree of starch in feed of weaned piglets is not the higher the better.The effect of more than 50% gelatinization degree on the growth performance of piglets was not significant,and the production cost would also be increased.