Effects Of Wheat Particle Size On The Growth Performance And Gastrointestinal Tract Traits Of Broilers Based On Different Feed Form

The current study with a 2×5 factorial arrangement of treatments was applied with 10 treatments of 7 replicates each to investigate the effects of feed form(mash and pellet)and wheat particle size(2,4,6,8,10 mm)on the growth performance and gastrointestinal tract traits of broiler aged from 1 to 42d.(1)The broilers fed the pellet diets had higher AFI(P<0.05)and BWG(P<0.01)over the course of the experiment,lower F/G(P<0.01)in the starter phase and no difference in the F/G during the grower phase between the feed forms.The apparent digestibility of 18?20d crud protein and 39?41d ethyl ether extract in mash diet is lower(P<0.01,P<0.05)than pellet diet.An interaction between the feed form and particle size was observed on the GLU at 42d(P<0.05),the GLU increase in mash diet but decrease in pellet diet as the WPS increase.With the mash diets broilers showed the best growth performance when the wheat particle size was 2mm.With the pellet diets,the broilers showed the best growth performance when the WPS was 4mm.A quadratic(P<0.01)response was observed in the BWG of the starter phase for pellet diet as the WPS increased.A linear increase and quadratic(P<0.01)effect were observed in the F/G through the course of the experiment as the particle size increased in both feed forms.A linear increase and quadratic(P<0.01)effect were observed in the apparent digestibility of 39?41 dethyl ether extract?dry matter and the apparent metabolizable energy.A linear increase and quadratic effect were observed on the GLU at 42d in pellet diet(P<0.05)(2)The relative weight of the gizzard and pancreas,the relative lengths and weight of the digestive tract on both 21 d and 42d of mash diet is higher than the broilers fed on pellet diet(P<0.01).An interaction between the feed form and particle size was observed on the relative weight of the gizzard on 21d(P=0.05)and the liver at 42d(P=0.03).An interaction between the feed form and particle size was observed on relative weight of the cecum on 21d.The relative weight of the cecum on 21d increase in mash diet but decrease in pellet diet when wheat particle size increase.In the mash diet,a linear increase and quadratic effect were observed in the relative weights of the gizzard,relative length of the duodenum and relative weight of cecum(P<0.01,P<0.05,P=0.05)on 21d and liver(P<0.05)on 42d as the particle size increased.In the pellet diet a linear decrease was observed in the relative weights of the gizzard on 21d and liver on 42d as the particle size increased.(3)The mash diets resulted in a higher V/C as well as higher villus height at 21 d than pellet diet(P<0.01).With the mash diet,A linear increase was observed on the villus height?mucosa muscular layer thickness and V/C,the relative expression of ZO-l,claudinl and occludin at 21d,villus height,mucosa muscular layer thickness at 42d as the particle size increased,but linear decrease in ZO-1,claudinl and occludin at 42d(P=0.05,P<0.01,P=0.07)as the WPS increase.With the pellet diets,a linear increase was observed in the villus height,crypt depth,and V/C at 42 d(P<0.01,P=0.02,P<0.01)as the WPS increase.A quadratic effect(P<0.01)was observed in the villus height,crypt depth,mucosal thickness and V/C at 21 d and 42 d in both feed form as the WPS increased.A quadratic(P<0.01)effect was observed in the relative expression of claudin1 at 21d and ZO-1,claudinl as well as occludin at 42d as the WPS increase.The particle size and feed form showed interaction in the villus height(P<0.01),crypt depth(P<0.01),mucosa muscular layer thickness(P=0.02)and V/C(P<0.01)at 21 d,as well as in the crypt depth and V/C at 42 d(P<0.01).With the pellet diet,a linear increase(P<0.01)and quadratic effect(P<0.05)were observed on the relative expression of ZO-1,claudinl and occludin at 21d as the WPS increase.(4)The AOD of the jejunum goblet cell at both 21d and 42d were higher than the pellet diets(P<0.01).The relative expression of IL-1? and IFN ? at 21d is higher(P=0.02,P<0.01)than the pellet diet,but the IL-17 at 42d lower(P<0.05)than pellet diet.With the mash diet,there was linear increase(P<0.01)in the OD of the jejunum goblet cell at 21d as the WPS increase.A quadratic effect was observed in the relative expression of IL-6 and IFN Y(P=0.06,P=0.02)as the WPS increase;A linear decrease and quadratic effect(P<0.05)were observed on the IL-1?,IFN? and IL-4 at 42d as the WPS increase.A quadratic(P<0.01)effect was observed in the jejunum goblet cell at 21d and 42d in mash diet and at 42d in pellet diet(P<0.01).With the pellet diet,there was linear increase and quadratic effect in the IFNa and IL-4 as the WPS increase(P<0.05).(5)The number of lactobacillus and clostridium perfringens at 21d as well as the salmonella at 42d in mash diet was higher than that in the pellet diet.The butyric acid of the cecal digesta in mash diet was lower(P=0.08)than the pellet diet.A linear increase and quadratic effect(P<0.05)were observed on the number of lactobacillus in both feed form as WPS increase.A linear decrease and quadratic effect(P<0.05)were observed on the number of the clostridium perfringens,salmonella and escherichiacoliat both 21d and 42d in both feed form as WPS increase.With the mash diet,there was linear increase in the amount of acetic acid and butyric acid at 21d and propanoic acid at 42d as the WPS increase(P<0.05).The results showed that the growth performance of mash diet is worse than pellet diet;The digestive organ,the relative expression of tight junction,the inflammatory factor and the total amount of microflora was higher than the pellet diet.With the mash diet,there was linear decrease in the nutrition utilization and linear increase in the jejunum villus height,mucosa muscular layer thickness,V/C,the OD of jejunum goblet cell,the relative expression of the tight junction of jejunum and the number of lactobacillus in cecal as the WPS increase.However the number of clostridium perfringens?salmonella and coli in cecal decreased as the WPS increase.With the pellet diet there was linear increase in the F/G,GLU,jejunum villus height,mucosa muscular layer thickness,V/C and the relative expression of the tight junction and IFN ??IL-4 as the WPS increase.There was linear increase in the number of lactobacillus in cecal in both feed form as the WPS increase.A linear decrease and quadratic effect was observed in the number of clostridium perfringens,salmonella and escherichia coli in cecal as the WPS increase.