This study aimed to evaluate the effects of supplementing broiler diets with a dietary protease on growth performance, digestive function, intestinal morphology, and meat quality as compared with feeding diets with or without an antibiotic growth promoter (AGP). A total of 240 1-day-old male chicks (Cobb 500, 48.3 ± 3.3 g) were distributed to 3 treatments with 8 replicates (10 birds per replicate). Three treatments were: 1) corn-soybean meal basal diets (CTRL); 2) basal diets with 0.003% avilamycin (AB); 3) basal diets with 0.0125% protease (PRT). The diets were provided as mash form, and birds were fed ad libitum during the whole experimental period. On d 45, birds were euthanized, and tissue and digesta samples were collected. On d 46, the remaining birds were processed in a commercial slaughterhouse, and breast muscle samples were collected. Despite a trend for a decreased feed conversion ratio (FCR) in the AB group during the whole phase (P = 0.071), no significant differences in growth performance parameters and relative weights of organs were observed (P > 0.05) among the groups. The AB and PRT groups showed significantly greater apparent ileal digestibility of amino acids compared with the CTRL group (P < 0.05). The PRT group significantly improved the morphology of duodenum and jejunum (P < 0.05). No differences were detected for meat quality, white striping and woody breast among the groups (P > 0.05). For the gene expressions, the AB group showed a greater level of B0-system neutral amino acid co-transporter 1 (B0AT1) and excitatory amino acid transporter 1 (EAAC1) mRNA abundance compared with PRT group while a significantly lesser level of cationic amino acid transporter 1 (CAT1) mRNA abundance was observed in the AB group compared with CTRL group (P < 0.05). The PRT group had a lesser level of peptide transporter 1 (PepT1) mRNA abundance in the jejunum than the CTRL group (P < 0.05). The highest mRNA abundances of zonula occludens-1 (ZO1) and cadherin 1 (CDH1) were observed in the CTRL group (P < 0.05). In conclusion, supplementation of avilamycin tended to reduce FCR and significantly improved amino acids utilization and supplementation of dietary protease significantly enhanced intestinal morphology and amino acids utilization in broilers. In that respect, exogenous protease use appears to be an interesting tool to be considered in AGP reduction strategies.

A total of 320 1-day-old Cobb 500 chicks with an initial weight of 48.3 ± 3.3 g per pen were assigned to 4 dietary treatments with 8 replicates provided in 3 phases for 46 days. The treatments were fed as mash diets and included :1) negative control (NC) corn-soybean basal diet, 2) positive control (PC) basal diet with 30 ppm avilamycin, 3) basal diet supplemented with 1000 ppm RDE (RDE1), and 4) basal diet with 3000 ppm RDE (RDE2). Results showed reduced jejunal crypt depth in RDE1 and increased villus: crypt ratio in groups (either RDE1 or RDE2) (P < 0.05). Cationic amino acid transporter mRNA abundancce was decreased (P < 0.05) in RDE1, RDE2, and PC treatments, but peptide and neutral amino acid transporter mRNA abundance were higher (P < 0.05) in RDE2 compared to NC. Apparent ileal digestibility of crude fat was increased in RDE2 and PC compared to NC, whereas amino acid digestibility was greater in RDE1, RDE2, and PC (P < 0.05). In conclusion, red osier dogwood had no effect on growth performance, improved the intestinal health and function of broiler chickens, and had no detrimental effects on meat quality.

Essential oils are potential antimicrobial alternatives and their applications in animal feeds are limited due to their fast absorption in upper gastrointestinal tract. This study investigated the effects of encapsulated cinnamaldehyde (CIN) at 50 mg/kg or 100 mg/kg on the growth performance, organ weights, meat quality, intestinal morphology, jejunal gene expression, nutrient digestibility, and ileal and cecal microbiota. A total of 320 male day-old broiler Cobb-500 chicks were randomly allocated to 4 treatments with 8 pens per treatment (10 birds per pen): 1) basal diet (negative control, NC); 2) basal diet supplemented with 30 mg/kg avilamycin premix (positive control, PC); 3) basal diet with 50 mg/kg encapsulated CIN (EOL); 4) basal diet with 100 mg/kg encapsulated CIN (EOH). Despite birds fed EOH tended to increase (P = 0.05) meat pH at 24 h, all pH values were normal. Similar to PC group, meat from birds fed EOL and EOH showed a reduced (P &lt; 0.05) Warner-Bratzler force shear (WBFS) compared to the NC group. The highest villus to crypt ratios (VH/CD; P &lt; 0.05) were observed in broiler fed either EOL or EOH, with an average being 14.67% and 15.13% in the duodenum and 15.13% and 13.58% in the jejunum, respectively. For jejunal gene expressions, only six out of the 11 studied genes showed statistically differences among the dietary treatments. Gene expressions of cationic amino acid transporter 1 (CAT-1) and neutral amino acid transporter 1 (B 0AT-1) were upregulated in EOH-fed birds compared to PC and NC-fed birds (P &lt; 0.05), respectively; while expression of proliferating cell nuclear antigen (PCNA) were downregulated in EOL-fed birds when compared to NC birds (P &lt; 0.05). Nonetheless, the expressions of cadherin 1 (CDH-1), zonula occludens 1 (ZO-1), and maltase-glucoamylase (MG) were all upregulated (P &lt; 0.05) in EOH-fed birds compared to PC-fed birds. The apparent ileal digestibility (AID) of dry matter, crude protein, crude fat and of all 18 tested amino acids increased in EOL-fed birds (P &lt; 0.01). Additionally, relative abundances (%) of ileal Proteobacteria decreased, while ileal and cecal Lactobacillus increased in EOH-fed birds (P &lt; 0.05). In conclusion, dietary encapsulated CIN improved meat quality and gut health by reducing meat WBFS, increasing VH/CD in intestines, jejunal gene expressions, AID of nutrients and beneficially ileal and cecal microbiota composition.

Background: Essential oils are potential antimicrobial alternatives and their applications in animal feeds are limited due to their fast absorption in upper gastrointestinal tract. This study investigated the effects of encapsulated cinnamaldehyde (CIN) at 50 ppm or 100 ppm on the growth performance, organ weights, meat quality, intestinal morphology, jejunal gene expression, nutrient digestibility, and ileal and cecal microbiota. A total of 320 male day-old broiler Cobb-500 chicks were randomly allocated to 4 treatments with 8 pens per treatment (10 birds per pen): 1) basal diet (negative control, NC); 2) basal diet supplemented with 30 ppm avilamycin premix (positive control, PC); 3) basal diet with 50 ppm encapsulated CIN (EOL); 4) basal diet with 100 ppm encapsulated CIN (EOH). Results: Despite birds fed EOH tended to increase (P = 0.05) meat pH at 24 h, all pH values were normal. Similar to PC group, meat from birds fed EOL and EOH showed a reduced (P < 0.05) Warner-Bratzler force shear (WBFS) compared to the NC group. The highest villus to crypt ratios (VH/CD; P < 0.05) were observed in broiler fed either EOL or EOH, with an average being 14.67% and 15.13% in the duodenum and 15.13% and 13.58% in the jejunum, respectively. For jejunal gene expressions, only six out of the 11 studied genes showed statistically differences among the dietary treatments. Gene expressions of cationic amino acid transporter 1 (CAT-1) and neutral amino acid transporter 1 (B0AT-1) were upregulated in EOH-fed birds compared to PC and NC-fed birds (P < 0.05), respectively; while expression of proliferating cell nuclear antigen (PCNA) were downregulated in EOL-fed birds when compared to NC birds (P < 0.05). Nonetheless, the expressions of cadherin 1 (CDH-1), zonula occludens 1 (ZO-1), and maltase-glucoamylase (MG) were all upregulated (P < 0.05) in EOH-fed birds compared to PC-fed birds. The apparent ileal digestibility (AID) of dry matter, crude protein, crude fat and of all 18 tested amino acids increased in EOL-fed birds (P < 0.01). Additionally, relative abundances (%) of ilealProteobacteriadecreased,while ileal and cecal Lactobacillusincreasedin EOH-fed birds(P< 0.05).Conclusions: Dietary encapsulated CINimproved meat quality and gut health by reducingmeat WBFS,increasing VH/CD in intestines, jejunal gene expressions, AID of nutrients and beneficiallyileal and cecal microbiota composition.

This study investigated the effects of encapsulated citral (CIT) and cinnamaldehyde (CIN) on growth performance, intestinal morphology and meat quality in broilers. A total of 320 0-day-age male broilers (Cobb 500) were allocated 32 pens with 8 pens per treatment. The treatments included: 1) Corn-wheat-SBM basal diet (negative control); 2) basal diet with 30 ppm avilamycin premix (positive control); 3) basal diet with 50 ppm encapsulated CIT and CIN (CCL); 4) basal diet with 100 ppm encapsulated CIT and CIN (CCH). There were no significant differences between treatments in growth performance (P &gt; 0.05) at each feeding stage. Additionally, birds had similar relative organ weights of heart, liver, spleen and bursa (P &gt; 0.05). The higher ratios of villus height to crypt depth (VCR; P ≤ 0.05) were detected in broilers fed either CCL or CCH, with an average being 14.67 and 15.13 in the duodenum, and 15.13 and 13.58 in the jejunum, respectively. Regarding meat quality, a higher pH value (pH = 6.21) in the breast was observed in 24-h post mortem chickens fed CCL (P ≤ 0.05). No significant differences of pH were detected in the breast in 96-h post mortem birds. The breast color (redness, yellowness, and lightness) in either 24-h or 96-h post mortem chickens was not significantly different among treatments (P &gt; 0.05). No change in purge loss (%) was observed in the breast after 48 h. The severity of white striping (WS) or woody meat (WB) was higher in the positive control (WS = 0.58; WB = 0.15) than in other treatments (P ≤ 0.05). In conclusion, dietary treatment with encapsulated CIT and CIN improved gut morphology and meat quality of broilers by increasing VCR in the small intestine and reducing the severity of WS/WB in the breast, respectively, without affecting growth performance.