| In this experiment,the effects of maize crushing size on the quality of pelleted feed and the performance,slaughter performance and digestive tract index were studied by processing corn pellet feed with different crushed size.The corn was crushed by a hammer mill(sieve opening: 1.5,3.0,4.5 mm)to obtain three kinds of corn particles with logarithmic geometric mean particle diameters of 232 ?m,319 ?m and 380 ?m.The same formulation and Process parameters processed into different sizes of corn broiler diet.A total of 216 chickens were randomly divided into 3 groups and fed with the above three kinds of broiler chickens,6 replicates in each group and 12 chickens each for 65 days.The pulverized yield,energy consumption,and the geometric mean particle size of the corn particles after pulverization were analyzed,and the PDI and hardness of the pellets were analyzed.The test results are as follows:1)The logarithmic geometric mean particle size of 1.5,3.0 and 4.5 mm groups increased with the increase of pore size,and the difference was significant(P <0.05).The average particle size difference(P <0.05),and the standard deviation of average particle size in 1.5 mm treatment group was the smallest,which indicated that the uniform mixing performance was the best.2)The distribution of maize crushing grain size in 1.5 mm sieve was not obeying the normal distribution at the significance level a = 0.05;at the significance level a = 0.05,the distribution of the grain size of corn under 3.0 mm was obey the normal distribution At the significance level a = 0.05,the distribution of the grain size of corn under 4.5 mm sieve follows the normal distribution.3)The pulverized energy consumption decreases with the increase of the pore size of the crushed sieve;the pulverized yield increases slightly with the increase of the pore size of the sieve,and the pulverized yield of the 1.5 mm group is the lowest;the temperature rise does not show regular changes with the increase of the pore size of the sieve;(P <0.05).The loss of 1.5 mm group was significantly higher than that of 4.5 mm group(P <0.05).4)1~21-d-old broiler of the coefficient of variation increases with increasing grain size of corn,but had no significant effect on it(P> 0.05),22~65-d-old broiler semi-finished product the coefficient of variation of the 1.5mm group was the best.The coefficient of variation of 3.0mm group was poor.The increase of grain size of corn had no significant effect on the mixing uniformity(P> 0.05).5)The PDI of the pre-pelleted feed decreases with the increase of the pore size of the sieve.The particle durability of the 1.5 mm group was significantly different from that of the 3.0 mm and 4.5 mm groups(P <0.05).The PDI of the later pellets increased first and then increased with the increase of the pore size of the sieve.1.5 mm group and 3.0mm group significant difference(P <0.05),and the pellet durability in the 3.0 mm group was the lowest.The results showed that the hardness of the pellets increased with the increase of the pore size of the pellets,but the difference was not significant.The hardness of the pellets increased first and then decreased with the increase of the pore size,and 1.5mm had the maximum grain hardness,there was no correlation between particle durability and hardness.6)The grain size of different maize had no significant effect on ADG of 1 ~ 35-d old,36 ~ 65-d-old and full-time broiler(P> 0.05),the ADG in the 319 ?m group was larger than that in the 232 ?m and 380 ?m groups(P> 0.05).There was no significant difference in the grain size of maize between 1 ~ 35-d-old and full-time broiler(P> 0.05).The ADFI of 36 ~ 65-d-old and full-time broilers showed a decreasing trend with the increase of maize crushing grain size.The ADFI of the 380 ?m group was significantly lower than that of the 232 ?m group and the 319 ?m group(P <0.05)at 36 ~ 65-d-old.The grain size of different maize had no significant difference in F / G between 36 ~ 65-d-old(P > 0.05).The F / G of the 319 ?m group was significantly lower than that of the 232 ?m and 380 ?m groups at 1 ~ 35-d old(P <0.05),and There was no significant difference between 380 ?m group and 232 ?m group(P> 0.05).7)There were no significant differences in the slaughter rate,semi-net load rate and full net load of broilers in 232 ?m group,319 ?m group and 380 ?m group(P> 0.05).8)The body weight index,duodenal body mass index,ileum body mass index,ileum body mass index,cecal body mass index,duodenal length index,jejunum length index,ileal length index,cecum Length index had no significant effect(P> 0.05).The body mass index of muscle and stomach increased significantly with the increase of grain size(P <0.05).The intestine body mass index and the small body mass index of the 32-day-old broiler group were significantly less than 319 ?m and 380 ?m(P <0.05),but there was no significant difference between the 380 ?m group and the 319 ?m group(P> 0.05).The length of small intestine in 319 ?m group was significantly higher than that in 380 ?m group and 232 ?m group(P <0.05).There were no significant differences in body mass index,muscle mass index,duodenum index,jejunum body mass index,cecal body mass index,duodenal length index,jejunum length index and cecal length index of different maize crushed grains(P> 0.05).In summary,the results of this test are:1.The logarithmic geometric mean particle size of corn particles increased significantly with the increase of pore size;The smaller the pore size of the sieve,the better the uniformity of the corn particles after crushing.With the increase of the aperture aperture,the energy consumption of the mill is decreasing,and the output is increasing.The size of the corn particles was not affected by the mixed evenness,PDI and hardness of the broiler pellet feed,and there is no correlation between the durability and the hardness of the particles.2.The size of crushed corn had no significant effect on the growth performance of broilers,but the broilers fed with diet using corn at size of 319 ?m showed the best.The size of crushed corn had no significant effect on slaughter performance.The proventriculus relative empty weights of broilers had increased with the increase of grain size,the small intestine relative empty weights and ileum relative empty weights of 65-d-old broilers had significantly increased with the increase of grain size. |
PDF Full Text Request