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.

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.

Evaluation of early feed access and algal extract on growth performance, organ development, gut microbiota and vaccine-induced antibody responses in broiler chickens.

Hatching concepts such as on-farm hatching provide an opportunity to supply newly hatched chickens with optimal nutrition that support growth and development of a healthy gut. Brown algae contain bioactive compounds, especially laminarin and fucoidan that may improve intestinal health and immune responses. This study aimed to examine the effects of early access to feed and water posthatch and feed supplementation with algal extract rich in laminarin from Laminaria digitata, on growth performance, organ and microbiota development and antibody production. A total of 432 Ross 308 chicks were allotted to 36 rearing pens in a 2 × 3 factorial design with two hatching treatments and three dietary treatments. During chick placement, half of the pens were directly provided access to feed and water (Early) while half of the pens were deprived of feed and water for 38 h (Late). The chicks were fed three different starter diets until day 6; a wheat-soybean meal-based control diet, a diet with low inclusion of algal extract (0.057%) and a diet with high inclusion of algal extract (0.114%). Feed intake and BW were registered on pen basis at placement, days 1, 6, 12, 19, 26, 33 and 40. To induce antibody responses, all chicks were vaccinated against avian pneumovirus on day 10. Three chicks per pen were selected as focal animals and used for blood sampling on days 10 and 39. On days 6, 19, and 40, two birds per pen were killed and used for organ measurement and caecal digesta sampling for gut microbiota analysis using the Illumina Miseq PE 250 sequencing platform. Results showed that algal extract did not influence gut microbiota, gut development or vaccine-induced antibody responses. However, during the first 38 h, early-fed chicks consumed on average 19.6 g of feed and gained 27% in BW, while late-fed chicks lost 9.1% in BW which lowered BW and feed intake throughout the study (P < 0.05). Late chicks also had longer relative intestine, higher relative (g/kg BW) weight of gizzard and proventriculus but lower relative bursa weight on day 6 (P < 0.05). No effects of hatching treatment on microbiota or antibody response were detected. The microbiota was affected by age, where alpha diversity increased with age. In conclusion, this study showed that early access to feed but not algal extract improved the growth performance throughout the 40-day growing period, and stimulated early bursa development.

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.

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.

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.

Indigenous knowledge on the nutritional quality of urban and peri-urban livestock feed resources in Kampala, Uganda.

This study identified the indigenous criteria used by livestock farmers in urban and peri-urban areas of Kampala to assess the nutritional quality of available feed resources. Focus group discussions and questionnaire interviews (with a total of 120 livestock farming households) were conducted. The findings showed that banana peels, leftover food and own-mixed feeds were the most commonly used feed resources for cattle, pigs and chickens, respectively. Farmers use several indigenous criteria to judge the nutritional quality of the available feed resources. These included perceived effects on disease resistance, feed intake, growth/body condition, hair coat appearance, faecal output, faecal texture and level of production, among others. According to farmers, animals offered with a feed resource of good nutritional quality are more resistant to diseases, ingest much of the feed, gain weight with well-filled bodies, have smooth hair coats, produce large quantities of faeces that are not too firm or watery and exhibit good performance (lactating cows produce more milk, sows produce piglets of good body size, hens lay more eggs of normal size, etc.). Although this indigenous knowledge exists, farmers put more importance on availability and cost as opposed to nutritional quality when choosing feed resources. This explains why banana peels were among the feed resources perceived to be of low nutritional quality but, at the same time, were found to be the most commonly used. Hence, there is a need to sensitise farmers on the importance of nutritional quality in ensuring better and efficient utilisation of the available feed resources.

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.

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.