Live black soldier fly (Hermetia illucens) larvae in feed for laying hens: effects on hen gut microbiota and behavior

This study examined the effects of including live black soldier fly (BSF, Hermetia illucens) larvae in the diet of laying hens on gut microbiota, and the association between microbiota and fearfulness. A total of 40 Bovans White laying hens were individually housed and fed 1 of 4 dietary treatments that provided 0, 10, 20%, or ad libitum daily dietary portions of live BSF larvae for 12 wk. Cecum microbiota was collected at the end of the experiment and sequenced. Behavioral fear responses to novel objects and open field tests on the same hens were compared against results from gut microbiota analyses. The results showed that the bacteria genera Enterococcus, Parabacteroides, and Ruminococcus torques group were positively associated with increased dietary portion of live larvae, while Lactobacillus, Faecalibacterium, Bifidobacterium, Subdoligranulum, and Butyricicoccus were negatively associated with larvae in the diet. Inclusion of larvae did not affect fear behavior, but the relative abundance of Lachnospiraceae CHKCI001 and Erysipelatoclostridium was associated with fear-related behaviors. Further studies are needed to determine whether the change in gut microbiota affects fearfulness in the long-term.

Effects of algal supplementation in feed to broiler breeders on transfer of nutrients and antibodies to chicks and quality of hatchlings

Breeder nutrition is an important factor for chick quality since the chick embryo relies on nutrients available in the egg for growth and development. In addition, the egg is providing the chick with important antibodies that are vital during the first weeks of life. Brown algae contains several bioactive compounds, and dietary supplementation with algal extracts have shown improved gut health and immune responses in both pigs and poultry. The aim of this study was to investigate if feeding the brown algae Saccharina latissima, intact or as an extract, to broiler breeders can affect breeder hens' antibody responses to vaccination, egg quality and transfer of antibodies and nutrients to the egg and thereby improve the quality of newly hatched chicks. Forty-five hens and nine roosters of the parent lines of the fast-growing broiler Ross 308 were included in the experiment where hens were 31 weeks at the start. The hens were housed individually and fed one of three dietary treatments for seven weeks; (a) control, (b) addition of 0.6% algal meal or (c) addition of 0.08% algal extract. The hens were given a booster vaccination against infectious bronchitis virus (IBV) 21 days after the start of experiment. During experimental days 32-42, hens were naturally mated every 5th day and hatching eggs were collected. A total of 255 chicks were hatched, and chick quality was assessed. Moreover, on chick day three, blood was collected from 48 focal chickens and total immunoglobulin Y levels and specific titres to IBV in serum were determined. The results showed that feeding the brown algae Saccharina latissima, intact or as an extract to broiler breeders did not affect egg production, egg quality, antibody responses to vaccination or transfer of antibodies from hen to chick. However, feeding intact algae significantly increased the levels of iodine and decreased the level of selenium in the eggs and resulted in a lower proportion of chicks with maximum quality score. Interestingly, algal feeding, both intact and as an extract, increased the abdominal fat pad in broiler breeders by about 17% without affecting BW. In conclusion, supplementation of broiler breeder diets with algal extract from Saccharina latissima, but not intact algal meal is a promising dietary strategy to increase the abdominal fat pad without causing any adverse effects on nutrient level in eggs or chick quality.

Intestinal colonization with Campylobacter jejuni affects broiler gut microbiota composition but is not inhibited by daily intake of Lactiplantibacillus plantarum

Introduction

Lactobacilli may prevent broilers from colonization with Campylobacter spp. and other gram-negative zoonotic bacteria through lactic acid production and modulation of the intestinal microbiota. This study evaluated the effects of daily intake of Lactiplantibacillus plantarum 256 (LP256) on Campylobacter jejuni (C. jejuni) loads in ceca and feces of C. jejuni challenged broilers, together with the changes in the gut microbiota.

Methods

Two experiments were conducted using the broilers Ross 308 (R-308; Experiment 1) for 42 days and Rowan Ranger broilers (RR; Experiment 2) for 63 days. The LP256 strain was administered either via silage inoculated with LP256 or direct supplementation in the drinking water. Concurrently, haylage as a forage similar to silage but without any inoculum was tested. C. jejuni loads in fecal matter and cecal content were determined by plate counts and qPCR, respectively. The cecal microbiota, in response to treatments and the challenge, were assessed by 16S rRNA sequencing.

Results and Discussion

Culturing results displayed a significant reduction in C. jejuni colonization (2.01 log) in the silage treatment in comparison to the control at 1 dpi (day post-infection) in Experiment 1. However, no treatment effect on C. jejuni was observed at the end of the experiment. In Experiment 2, no treatment effects on C. jejuni colonization were found to be statistically significant. Colonization load comparison at the peak of infection (3 dpi) to that at the end of the trial (32 dpi) revealed a significant reduction in C. jejuni in all groups, regardless of treatment. Colonization dynamics of C. jejuni in the cecal samples analyzed by qPCR showed no difference between any of the treatments in Experiment 1 or 2. In both experiments, no treatment effects on the cecal microbiota were observed. However, proportional changes in the bacterial composition were observed after the C. jejuni challenge, suggesting that colonization affected the gut microbiota. Overall, the daily intake of LP256 was not effective in reducing C. jejuni colonization in either broiler type at the end of the rearing period and did not cause any significant changes in the birds' cecal microbiota composition.

From sewage sludge ash to a recycled feed phosphate - digestibility of precipitated calcium phosphate in broiler chickens and growing pigs

Today, EU is largely (∼92%) dependent on the import of phosphates as most mines are located outside Europe. Because of the limited availability, phosphorus (P) is included on the list of Critical Raw Materials. Precipitated calcium phosphate (PCP) recovered from sewage sludge ash is a novel and sustainable option to replace mined P as raw material in feed phosphates, e.g. monocalcium phosphate (MCP) or dicalcium phosphate, but the digestibility has not yet been tested in vivo. The aim was therefore to determine PCP and MCP apparent ileal digestibility (AID) of P in broiler chickens and apparent (ATTD) and true (TTTD) total tract digestibility of P in growing pigs. A chicken study comprised 240 Ross 308 chickens that were housed in groups of eight from day 21 to day 28. Five diets were used, a basal diet and two test diets, which contributed either 0.075% (low) or 0.150% (high) additional P for each of the test sources (MCP and PCP). The basal and test diets were composed to achieve increasing levels of P and AID was calculated with regression analysis. In the pig study, eight individually housed pigs were used in a change-over study with two experimental periods. The pigs were fed a basal P-free diet in a preperiod to be able to estimate endogenous P losses and then two different diets in two periods using a change-over design, where MCP and PCP were the only P source, providing in total 0.33 (basal diet), 4.42 (MCP) and 3.53 (PCP) g kg^-1P, respectively. The AID of P in PCP and MCP for chickens was 58.4 and 75.1% (P = 0.166). The ATTD and TTTD of P in PCP for pigs were 58.4 and 67.2%, respectively, which was lower (P < 0.001) than the corresponding values for MCP (82.1 and 89.1%), respectively. The digestibility of calcium (Ca) did not differ in the chicken diets with high inclusion levels of PCP and MCP (54.7 and 55.3%, respectively, P = 0.535), but was lower for PCP than MCP in the pig study (57.8 and 70.8% respectively, P = 0.001). In conclusion, the digestibility of P in PCP for chickens did not differ from conventional MCP, whereas for pigs, it was lower, but could be a viable alternative to other common sources of P.

Effects of access to feed, water, and a competitive exclusion product in the hatcher on some immune traits and gut development in broiler chickens

This study evaluated the effect of access to feed, water, and the competitive exclusion (CE) product Broilact®, administered in the hatcher, on broiler performance, caecal microbiota development, organ development, intestinal morphology, serum levels of IgY and vaccine-induced antibody responses.In total, 250 chicks were hatched in a HatchCare^TM hatcher and divided into four groups, given access to feed, water and the CE product sprayed on the chicks (CEs); access to feed, water, and the CE product in water (CEw); access to feed and water (Cpos); or no access to feed and water (Cneg) in the hatcher. At the research facility, 10 chicks per hatching treatment were euthanized for organ measurements. The remaining 200 chicks were randomly distributed to 20 pens. On d 11, all birds were vaccinated against avian pneumovirus (APV). Three focal birds per pen were blood-sampled weekly for quantification of IgY and serum antibodies to APV. On d 11 and 32, two birds per replicate pen were euthanised for organ measurements and sample collection. Feed intake and body weight were recorded weekly.Delayed access to feed and water reduced weight gain and feed intake early in life. At the end of the study, no differences in body weight remained.There were some early effects on organs, with depressed intestinal development and higher relative gizzard weight for the Cneg group at placement. No treatment effects on the immune traits measured were detected. The relative abundance of seven bacterial genera differed between treatment groups at d 11 of age. The results suggested that chickens are capable of compensating for 40 h feed and water deprival post-hatch. Provision of Broilact® did not have any persistent performance-enhancing properties, although different outcomes under rearing conditions closer to commercial production cannot be ruled out.

Feeding live Black Soldier Fly larvae (Hermetia illucens) to laying hens: effects on feed consumption, hen health, hen behavior, and egg quality

The use of insects in animal feed has the potential to reduce the demand for soybean production and reduce the deforestation and loss of natural resources. In particular, the black soldier fly (BSF, Hermetia illucens) larvae have received attention due to their ability to convert organic waste into high-value biomass. Several studies have investigated the effects of providing BSF larvae to both broilers and laying hens. However, knowledge gaps regarding hens’ voluntary intake of live larvae and the effects of larvae consumption on egg production still remain. Therefore, the aim of the present study was to determine the effects of the consumption of 4 different amounts of live BSF larvae on laying hen feed consumption, hen health and fearfulness, and egg production and quality. To this end, 40 Bovans White laying hens were housed individually and provided with 0, 10, 20% or ad libitum daily portions of live larvae from 18 to 30 wk of age. The larvae consumption and concentrate consumption, hen weight, egg production, and egg quality were monitored. Overall, differences were found between the hens given ad libitum access to larvae compared to the other treatments. Ad libitum hens, consumed 163 ± 41 g larvae/hen/day, consumed less concentrate (P = 0.03) and gained more weight (P = 0.0002) than all other treatments. They also had an overall higher consumption of protein, fat and energy (P < 0.03). There was no effect of larvae consumption on egg production, egg weight, shell thickness, shell breaking strength, or Haugh unit (P > 0.05). There was also no effect on hen behavior toward a novel object or in an open field test. This study is the first to provide different amounts of live BSF larvae, including an ad libitum portion to laying hens. The 20% diet could promote sustainability in the egg industry and be economically advantageous if BSF larvae can be bought in bulk for less than 40% of the cost of the concentrate.

Effect of hatching time on time to first feed intake, organ development, enzymatic activity and growth in broiler chicks hatched on-farm

The conventional commercial hatcheries used today do not allow the newly hatched chicks to consume feed or water. Combined with natural variation in hatching time, this can lead to early hatched chicks being feed-deprived for up to 72 h before being unloaded at the rearing site. This study investigated the effects of hatching time on time to first feed intake and development of organs, digestive enzymes and productivity in terms of growth and feed conversion ratio in chicks hatched on-farm. Chicks were divided into three hatching groups (early, mid-term and late), and assessed over a full production cycle of 34 days. The results revealed that chicks remain inactive for a considerable amount of time before engaging in eating-related activities. Eating activity of 5% (i.e. when 5% of birds in each hatching group were eating or standing close to the feeder) was recorded at an average biological age (BA) of 25.4 h and a proportion of 50% birds with full crop was reached at an average BA of 30.6 h. Considering that the hatching window was 35 h in this study, the average chick probably did not benefit from access to feed and water immediately post-hatch in this case. At hatch, mid-term hatchlings had a heavier small intestine (30.1 g/kg bw) than both early (26.4 g/kg bw) and late (26.0 g/kg bw) hatchlings. Relative length of the small intestine was shorter in late hatchlings (735 cm/kg bw) than in mid-term (849 cm/kg bw) and early (831 cm/kg bw) hatchlings. However, the relative weight of the bursa fabricii was greater in mid-term (1.30 g/kg bw) than in early hatchlings (1.01 g/kg bw). At hatch, late hatchlings were heavier than early and mid-term hatchlings (P < 0.05), but by 3 days of age early hatchlings were heavier than mid-term and late hatchlings (P < 0.01). The only effect persisting throughout the study was a difference in the relative weight of the small intestine, where late hatchlings had heavier intestines than early hatchlings (P < 0.05). Thus, while there were differences between hatching groups, this study showed that the hatchlings seemed capable of compensating for these as they grew.

Silage and haylage as forage in slow and fast-growing broilers - effects on performance in Campylobacter jejuni infected birds

1. This study investigated the effects of daily intake of silage or haylage on broiler production performance and organ development. Furthermore, effects of daily intake of Lactobacillus plantarum either via silage or by supplemented drinking water, on Campylobacter jejuni loads in faeces were studied. 2. To test this, a 42-d experiment using Ross 308 and a 63-d experiment with Rowan Rangers hybrids, were performed. Silage inoculated with L. plantarum strain 256 and haylage were fed in total mixed rations with mixtures of 85% of pellets and 15% of respective forage (DM-based weight). Feed intake (FI), forage intake, body weight (BW) and feed conversion ration (FCR) were monitored weekly. Mortality was recorded daily, and organ weights were registered at slaughter. Quantification of C. jejuni was performed by colony counts from faecal samples after culture on agar plates. 3. There was a negative effect of haylage on BW and FI in the fast-growing Ross 308 hybrid. Silage had a negative effect on BW only on week four and six. Water inoculated with L. plantarum 256 increased BW in the starter period. Interestingly, no significant adverse effect of forage inclusion was observed in the Rowan Ranger birds. 4. Relative weight of the emptied gizzard was higher in both Ross 308 and Rowan Ranger birds fed haylage and silage than in the control group. In Ross 308 birds, both forages significantly reased the relative weight of gizzard with digestive content when compared to birds fed solely pellets. 5. In both studies, higher consumption of silage than haylage was observed. 6. In conclusion, daily intake of L. plantarum 256 either via silage or supplemented in drinking water, was not effective in reducing the shedding of C. jejuni in either Ross 308 or Rowan Ranger hybrids at the end of the rearing period.

Evaluation of broiler chickens' digestibility of Neurospora intermedia biomass

A total of 70 broiler chickens were used to evaluate the apparent ileal digestibility coefficient (AIDC) of protein and amino acids, and apparent digestibility coefficient (ADC) of energy in the protein rich Fungal Biomass of Neurospora intermedia (FBN) obtained from bioethanol production. The chickens were housed in 10 pens with seven chickens per pen and fed one of two experimental diets between day 28 and 35 of age. The experimental diets were wheat-soybean meal-based control diet and a diet composed of 70% control diet and 30% of FBN. There were no difference (P > 0.05) between the control and FBN diet on chick feed intake and body weight at day 35. However, the AIDCs of crude protein and amino acids were significantly (P < 0.01) higher in control diet than in the FBN diet except for proline and phenylalanine. The AIDC of CP (0.74), cysteine (0.68), methionine (0.70), AME (15.6), and threonine (0.69) in FBN were comparable to the corresponding values in other protein-rich feedstuffs such as soybean meal and fish meal. The results from this study show that FBN may be an alternative protein source for poultry.

Body growth, intestinal morphology and microflora of quail on diets supplemented with micronised wheat fibre

1. Particle size reductions of fibre-rich materials alter structure, functional and digestive properties. To determine the effects of using fibre as an additive in Japanese quail rations on performance and gut physiology, a trial using micronised wheat fibre (MWF) at levels of 0.0, 5, 10 and 15 g/kg in feed was conducted. 2. Growth rate and feed efficiency were significantly improved when diets contained MWF while feed intake was not affected by levels of the fibre. As MWF content increased, the relative weight of gizzard and gastrointestinal tract (GIT) significantly increased whereas liver relative weight significantly decreased. 3. MWF inclusion significantly increased relative length of gut segments, villi height, villus thickness, the villi height to crypt depth proportion in jejunum and ileum and the number of goblet cells in different parts of intestine. 4. Tibia weight, length and ash content were increased linearly with rising MWF inclusion. Litter moisture was affected by MWF inclusions in a quadratic manner. The colony forming unit (CFU/g) of Streptococci spp. in ileal digesta was decreased with increasing MWF inclusion levels in the diet. 5. In conclusion, MWF can be used as a feed additive in quail diets and its inclusion in feed resulted in better performance, beneficial changes in intestinal microbial counts and improvements in small intestine morphology.

Chicory (Cichorium intybus L.) and cereals differently affect gut development in broiler chickens and young pigs

Dietary fiber, resistant to host-mediated digestion in the small intestine due to lack of endogenous enzymes, impacts many facets of animal health and is associated with gut development especially in young monogastrics. Furthermore, it can be used as in-feed antibiotic alternative. Chicory (Cichorium intybus L.) forage with high content of pectin (uronic acids as building blocks) is a novel class of dietary fiber that is chemically different from cereal grains (with high content of arabinoxylans). In the present study, we investigated effects of dietary inclusion of chicory forage on digestibility, gut morphology and microbiota in broilers and young pigs. In the chicken experiment, 160 1-d old broiler chicks were fed 3 nutritionally balanced diets for 30 d including a cereal-based diet and 2 diets with part of the cereals substituted with 60 and 120 g/kg chicory forage (CF60 and CF120), whereas in the pig experiment, 18 seven-wk old Yorkshire pigs were fed 3 diets for 18 d including a cereal-based diet and 2 diets with 80 and 160 g/kg chicory forage inclusion (CF80 and CF160). Our results showed that young pigs were capable to utilize chicory forage well with higher total tract apparent digestibility (TTAD) of all fiber fractions, particularly uronic acid, compared with the control (P < 0.01). In contrast, a decreased TTAD of all fiber fractions was observed in chickens fed on diet CF120 (P < 0.05). Moreover, diet induced changes in gut morphology were observed in the large intestine of chickens. The alteration of cecal mucosal thickness was further positively correlated with TTAD of non-starch polysaccharides (NSP) and its constituent sugars (P < 0.05). In addition, in pigs, terminal restriction fragment length polymorphism (T-RFLP) analysis of intestinal microbiota revealed substantial dietary effects (cereal control diet vs. chicory forage inclusion) on the relative abundance of 2 dominant bacterial phylotypes (Prevotella sp. vs. Roseburia sp.) respectively (P < 0.05). In conclusion, our data showed that chicory forage (Cichorium intybus L.), a novel dietary fiber source in animal nutrition, have potential beneficial properties as fiber ingredient in diets for both pigs and chickens.

Digestibility of fibre sources and molecular weight distribution of fibre fractions in ileal digesta of growing pigs

Seven post-valve T-caecum cannulated growing pigs were used in a change-over experiment with four diets and four 14-day periods to evaluate the total tract apparent digestibility (TTAD) and the ileal apparent digestibility (IAD) of diets with inclusion of chicory forage (CFO), sugar beet pulp (SBP), wheat bran (WB) and grass meal (GM), as well as the TTAD of the mentioned fibre sources. Moreover, this experiment evaluated the molecular weight distribution of soluble non-starch polysaccharide (NSP) fractions in diet and ileal digesta from pigs fed the CFO and SBP diets. The experimental diets were balanced to have similar NSP content and compromised of one part of the basal diet and one part of the four fibre sources (CFO, SBP, WB and GM). In addition, all pigs were fed the basal diet during a 14-day period before and after the experimental periods. Diet affected the TTAD of all dietary components except glucose. The TTAD of organic matter (OM) was higher for Diet SBP than for Diets WB and CFO, showing both were higher than Diet GM. The TTAD of NSP was higher for Diet SBP than Diets WB and GM. The IAD of OM was higher in Diet SBP than in the other diets. The IAD of NSP was lower in Diet WB than in the other diets. The TTAD of OM and energy of CFO was 0.43 ± 0.04 (standard error), which is similar to that reported for commonly used forage crops. The molecular weight distribution in ileal digesta showed different distributions between Diets CFO and SBP as well as between digesta from pigs fed these diets.

Molecular weight distribution of soluble fiber fractions and short chain fatty acids in ileal digesta of growing pigs

The effect of dietary fiber source on molecular weight (MW) distribution of soluble fiber fractions and short chain fatty acids (SCFA) in ileal digesta of 7 post valve T-cecum (PVTC) cannulated growing pigs was studied. Pigs were fed semisynthetic diets with sugar beet (Beta vulgaris) pulp (SBP) or chicory (Cichorium intybus) forage (CFO) as fiber sources of which the soluble nonstarch polysaccharide (NSP) fraction originated mainly from pectin. Three MW intervals were selected-large MW (MWL): 10,000,000 to 1,000,000 g/mol, medium MW (MWM): 1,000,000 to 200,000 g/mol, and small MW (MWS): 200,000 to 10,000 g/mol-and the relative distribution (% of total) of molecules in each interval was calculated. The MWM fraction was higher (P < 0.05) in ileal digesta of pigs fed diet SBP and the MWS fraction was higher (P < 0.05) in ileal digesta of pigs fed diet CFO. The mole/100 mole of propionic acid (HPr) was higher (P < 0.010) in pigs fed diet SBP whereas pigs fed diet CFO had higher (P < 0.010) mole/100 mole of acetic acid (HAc). The proportion of the MWL and MWM fractions in ileal digesta were negatively correlated to HAc (r = -0.52, P = 0.05, and r = -0.62, P = 0.02, respectively). The proportion of MWM in ileal digesta was positively correlated to HPr (r = 0.83; P = 0.001) whereas MWS and HPr were negatively correlated (r = -0.76; P = 0.002). In conclusion, the bacterial degradation of the soluble NSP fraction is selective and MW distribution may explain differences in SCFA production.

Impact of chicory inclusion in a cereal-based diet on digestibility, organ size and faecal microbiota in growing pigs

A total of 30 7-week-old pigs were used to evaluate the effects of chicory inclusion on digestibility, digestive organ size and faecal microbiota. Five diets were formulated: a cereal-based control diet and four diets with inclusion of 80 and 160 g/kg chicory forage (CF80 and CF160), 80 g/kg chicory root (CR80) and a mix of 80 g/kg forage and 80 g/kg chicory root (CFR). Generally, the pigs showed a high growth rate and feed intake, and no differences between the different diets were observed. The coefficients of total tract apparent digestibility (CTTAD) of energy, organic matter and CP did not differ between the control and CF80, whereas they were impaired in diet CF160. The CTTAD of non-starch polysaccharides and especially the uronic acids were higher (P < 0.05) with chicory inclusion, with highest (P < 0.05) values for diet CF160. Coliform counts were lower and lactobacilli : coliform ratio was higher (P < 0.05) in diet CFR than in the control. Global microbial composition was investigated by terminal restriction fragment length polymorphism combined with cloning and sequencing. Analysis of gut microbiota pattern revealed two major clusters where diet CF160 differed from the control and CR80 diet. Chicory forage diets were correlated with an increased relative abundance of one species related to Prevotella and decreased abundance of two other species related to Prevotella. For diet CFR, the relative abundance of Lactobacillus johnsonii was higher than in the other diets. This study shows that both chicory forage and root can be used as fibre sources in pig nutrition and that they modulate the composition of the gut microbiota differently.

Inclusion of chicory (Cichorium intybus L.) in pigs' diets affects the intestinal microenvironment and the gut microbiota

The content and composition of prebiotic plant fiber in the diet is important in promoting gut-related health. This study investigated the effects of the dietary inclusion of chicory forage and roots on the intestinal microenvironment of pigs. Thirty-seven-week-old pigs were fed 1 of 5 diets for 18 days, including a cereal-based control diet and 4 diets with the inclusion of 80 and 160 g kg(-1) of body weight chicory forage (CF80 and CF160), 80 g kg(-1) chicory root (CR80), and a mix of 80 g kg(-1) forage and 80 g kg(-1) chicory root (CFR). The animals maintained good performance and health irrespective of diet. Bacterial community structure and diversity in ileal and colonic samples was assessed using terminal restriction fragment length polymorphism (T-RFLP), combined with cloning and sequencing. Samples clustered perfectly according to gut segment with a higher bacterial diversity in colon than ileum. Distal ileum was dominated by lactic acid bacteria (LAB), and the relative amount of this group was increased by the CF160 and CFR diets. The colonic bacterial community was dominated by butyrate-producing bacteria and Prevotella. The increased relative abundance of butyrate-producing bacteria in the colon was positively correlated with the molar proportion of acetic acid and furthermore linked to the chicory forage diets (CF80 and CF160). Diets including chicory roots (CR80 and CFR) were correlated with a higher colonic abundance of Megasphaera elsdenii. The fermentation products and pH in digesta responded to diet type and were correlated with shifts in the microbiota, showing that chicory influences the intestinal microenvironment of pigs.

Growth performance, digestibility, and gut development of broiler chickens on diets with inclusion of chicory (Cichorium intybus L.)

A total of 256 broiler chickens (1 d old) were used in a 32-d growth trial to study the effects of chicory (Cichorium intybus L.) forage and root inclusion on growth performance, digestibility, and gut development. The chicory forage originated from 2 harvests (June and September) and was included at 60 and 120 g/kg. The chicory root was included alone at 60 g/kg or together with chicory forage, from both harvests, in equal amounts (60 g/kg). The cereal-based control diet and 7 experimental diets were fed to each of 4 pens of chickens (8 chickens/pen). A higher BW gain and lower feed conversion ratio were found at 13 d of age in chickens fed the 60 g/kg chicory forage diet (P ≤ 0.05), whereas performance did not differ between the control and 60 g/kg chicory root diets. In contrast, a lower performance and digestibility of DM, organic matter, and AME as well as a thinner cecal mucosa layer were found for the 120 g/kg chicory forage diet (P ≤ 0.05). No diet effects on organ parameters or on pH of cecum digesta were detected. The soluble nonstarch polysaccharides fractions of chicory forage did not have any major negative effects on performance and gut development, and chicory forage from the September harvest was seen to have a higher nutritional value than that from the June harvest. Thus, results from the current study suggest that chicory forage is a potentially useful fiber-rich feed ingredient with high palatability for broiler chickens.