Evaluation of a microbial muramidase supplementation on growth performance, apparent ileal digestibility, and intestinal histology of broiler chickens

The current study evaluated the effects of different inclusion levels of microbial muramidase (Muramidase 007, DSM Nutritional Products) on gastrointestinal functionality by determination of apparent ileal digestibility (AID) of nutrients, investigation of intestinal histomorphology, and quantification of resulting growth performance. Four maize-wheat-soybean experimental diets were produced without (C) and with different dosages of muramidase: low (L, 25,000 LSU(F)/kg), medium (M, 35,000 LSU(F)/kg), and high (H, 45,000 LSU(F)/kg); diets were fed to broilers for 35 d. At the end of the experiment, AID of ether extract (EE), crude protein (CP), Ca, and P were determined and samples of the mid-jejunum and -ileum were collected for histomorphological observations. Data were subjected to ANOVA analysis using the GLM procedure. Orthogonal polynomial contrasts were used to assess linear and quadratic effects of different levels of the muramidase. At the end of the trial, Muramidase 007 supplementation linearly increased body weight gain and decreased feed conversion ratio (FCR) (P ≤ 0.05). Adding the muramidase to broiler diets also linearly increased the European poultry efficiency factor (P ≤ 0.05). Inclusion of the muramidase in broiler diets linearly increased AID of CP, EE, and P (P ≤ 0.05), and the H group had a higher AID of EE and CP compared to C group (P ≤ 0.05). Microbial muramidase supplementation linearly increased ileal villus length to crypt depth ratio and decreased the number of ileal CD45 cells (P ≤ 0.05). Broilers fed M and H diets had fewer number of CD45 cells in the ileum compared to those in C group (P ≤ 0.05). In conclusion, the results of the present study demonstrated that inclusion of the microbial muramidase in broiler diets could increase AID of key nutrients and improve growth performance in broilers. Adding microbial muramidase to broiler diets can therefore be considered as an interesting prospect to improve gastrointestinal functionality. Biological mechanisms causing these improvements need to be studied further

Effects of grinding method, particle size, and physical form of the diet on gastrointestinal morphology and jejunal glucose transport in laying hens

Several studies illustrated that the structure of feed, i.e., the particle size, particle-size distribution, and the physical form of the diet, affects the avian gastrointestinal function and health leading to changes in productive performance. However, investigations concerning the effects of feeding differently processed diets on laying hens are limited and primarily concentrated on bird performance. The current study examines the effect of feed processing on the gastrointestinal morphology and on the jejunal glucose transport of laying hens. In 8 replicates, a total of 384 hens (Lohmann Brown) aged 20 wk were randomly allocated to 8 different groups and fed over a period of 21 d in a 3-factorial design. Diets differed in 1) grinding method, either hammer or roller mill; 2) physical form, either mash or expandate; and 3) particle size, either coarsely or finely ground. During the experimental trial, the laying performance of each feeding group was recorded daily and the feed intake and BW determined weekly. After slaughtering, the weights of the pancreas, proventriculus, gizzard, and small intestine were measured. Villus lengths and crypt depths of the duodenum, jejunum, and ileum were determined. The jejunal electrogenic glucose transport was studied in Ussing chambers. Hens that received mash instead of expandate had higher proventriculus (P = 0.011), gizzard (

The effects of different thermal treatments and organic acid levels on nutrient digestibility in broilers

Poultry feed is a potential vector for pathogens. Heat processing and organic acid treatments may decontaminate feed and can affect bird performance as well as feed digestibility. The present study was performed to investigate the effect of different thermal treatments including pelleting (P), longterm conditioning at 85°C for 3 min (L), or expanding at 110°C (E110) and 130°C for 3 to 5 s (E130) without or with 0.75 and 1.5% organic acid supplementation (63.75% formic acid, 25.00% propionic acid, and 11.25% water) on performance, nutrient digestibility, and organ weights of broilers. In total, 960 one-day-old broiler chicks were randomly assigned to 8 replicates using a 3 x 4 factorial arrangement. Performance variables were determined, and the relative organ weights and ileal and total amino acid (AA) digestibilities were measured at d 35. The organic acid inclusion linearly improved feed efficiency in the first week ('P' ≤ 0.05). The acid inclusion levels and thermal treatments had no significant effect on the performance variables at later intervals of the growing period of the birds. The L group showed the lowest ileal AA and CP digestibility. The inclusion of organic acids had a quadratic effect on total and ileal digestibility of isoleucine (P ≤ 0.05), whereas it had no significant effect on the ileal digestibility of other AA and nutrients. The relative weights of the jejunum and small intestine were significantly higher in the E130 group compared with P and L (P ≤ 0.05). In conclusion, our study demonstrated that long-term heat conditioning can decrease ileal nutrient digestibility, whereas pelleting and expansion, independently of organic acid addition, seemed to have no negative impact on broiler performance and nutrient digestibilities. Moreover, adding a blend of organic acids to broiler diets had neither positive nor negative effects on nutrient digestibility and final broiler performance. This indicates the feasibility of short-term thermal treatment and acid supplementation for hygienization of broiler feed without negatively influencing performance

The effect of feed particle size, milling method, and thermal treatment, on interior and exterior egg quality in laying hens

Quality egg production is the ultimate goal of layer farming. The grinding of grains to a more uniform particle size may improve the performance of mature birds (Amerah et al., 2007). Two methods, including hammer mill and roller mill, are commonly used to reduce particle size of grains (Amerah et al., 2007). Thermal treatment of feed is commonly used for feed sanitation, which may improve bird's performance (Kilburn and Edwards, 2001). The effect of the mentioned treatments on performance of poultry has widely been studied, however the knowledge regarding their impact on egg quality is limited. Therefore, the present study was designed to investigate the effects of feed grinding technique (roller (R) vs. hammer mill (H)), form of compaction (mash (M) or expandate (E)), and grinding intensity (coarse (C) vs. fine (F) particle size) on interior and exterior egg quality in layers

Implication of milling methods, thermal treatment, and particle size of feed in layers on mineral digestibility and retention of minerals in egg contents

Feed production with different milling methods, thermal treatment, and particle size may influence mineral digestibility and retention in eggs. The present study investigated the impact of roller (R) and hammer (H) mills, mash (M) and expandate (E) with fine (F) and coarse (C) particle sizes, on apparent ileal absorption (AIA) and apparent total digestibility (ATD) and retention of calcium, phosphorus, magnesium, zinc, manganese, copper and iron in yolk, albumen, and shell. A total of 384 hens (Lohmann Brown), 19 weeks old, were assigned using a randomized design with a 2 x 2 x 2 factorial arrangement. Eight experimental diets were offered ad libitum during the whole experimental period and one week before for diet adaption. The AIA of magnesium, zinc, copper, and iron was higher in treatment R in comparison with treatment H (

The effect of milling method, thermal treatment, and particle size of feed on exterior and interior egg quality in laying hens

Milling method, thermal treatment, and particle size are important variables determining feed production costs, feed intake and digestibility and potentially egg quality in laying hens. Besides the raw material, the energy needed during production has a major impact on the total feed costs and energy saving milling methods such as the roller mill are becoming more used in the feed industry. Diminution of feed is the largest energy cost in layer feed production (DEATON et al., 1989) and the second largest after pelleting in broiler feed production (REECE et al., 1985). Hammer mills and roller mills are commonly used to reduce particle size of grains (AMERAH et al., 2007; KOCH, 2002). The hammer mill is easier to handle and to maintain, but requires more energy than the roller mill (AMERAH et al., 2007). The hammer mill produces more spherical and uniform shaped particles (REECE et al., 1985), whereas the roller mill generates a more uniform particle size (AMERAH et al., 2007) with irregular cubic or rectangular shape (KOCH, 2002). In addition, hammer mills produce a greater amount of fine particles (REECE et al., 1985). Due to the fact that chickens have a preference for larger feed particles (SCHIFFMAN, 1968), the particle size distribution may affect egg quality, as nutrients may not be equally ingested or effectively utilized (TANG et al., 2006). In contrast, the comparison between corn based diets milled with hammer or roller mills showed no effects on bird performance and egg shell breaking strength (DEATON et al., 1989). Interestingly, layers fed with a barley based diet ground by roller mill had higher egg weight compared to the same diet produced by a hammer mill (HAMILTON, 1994). Layers fed a barley based diet ground by roller mill reduced feed intake and egg production as compared to maize and wheat diets, while no differences were observed when a hammer mill was used. Egg quality was not affected by milling methods (PEREZ-BONILLA et al., 2014)

The effects of different thermal treatments and organic acid levels in feed on microbial composition and activity in gastrointestinal tract of broilers

Thermal treatments of feed and organic acids are known to affect the gastrointestinal microbiota in chickens. The present study evaluated the effect of different thermal processes including pelleting (P), long-term conditioning at 85°C for 3 min (L), expanding at 110°C (E110), and 130°C for 3 to 5 s (E130) as well as organic acid (63.75% formic acid, 25.00% propionic acid, and 11.25% water) inclusion levels (0, 0.75, and 1.5%) on gastrointestinal microbiota in broilers. In total, 960 one-day-old chicks were randomly assigned to 8 replicates using a 3 x 4 factorial arrangement. At d 35, bacterial cell numbers in the crop, ileum, and cecum, and bacterial metabolites in the crop, gizzard, ileum, and cecum were determined. The inclusion of 1.5% organic acids increased cell numbers of all clostridial clusters in the crop. The organic acid supplementation increased the propionic acid concentration in the crop and gizzard and there was a decrease in lactic acid concentration. In the ileum, the 0% organic acid group had the highest numbers of 'Lactobacillus' spp. and enterobacteria. Inclusion of 1.5% organic acids increased ileal acetate concentration. Increasing the feed processing temperature led to an increase of lactobacilli in the crop and ileum, whereas clostridia and enterobacteria seemed unaffected. Similarly, lactate concentrations increased in the ileum, but short-chain fatty acids remained identical. In the crop, an increase for acetate was found for the E130 group compared with all other thermal treatments. In conclusion, our study demonstrated that thermal treatments and organic acid supplementation to broiler diets more markedly influenced the bacterial status of the crop compared with the downstream segments and their effects decreased along the length of gastrointestinal tract. Whereas organic acids markedly modified bacterial composition and activity in the crop, expansion increased lactobacilli and lactate in the crop and ileum