Valéria Farkas

The aim of this study was to gain a better understanding of the effects of oats, with and without hulls, on the histomorphometry parameters of the jejunum and ileum, the viscosity of the jejunal content and the ileal microbiota composition of broilers. A floor pen trial was carried out with 576 one-day-old Ross 308 broilers. Aside from a maize–soybean-based control diet (C), the two other treatments contained whole oats (WO) or dehulled oats (DO) in the starter (10%), grower (10%) and finisher (20%) phases. On day 39, eight chickens per treatment were slaughtered, and gut samples were collected for histology, jejunal chymus viscosity and ileal chymus microbiota analysis. Feeding the WO and DO diets increased the thickness of lamina propria in the jejunum, without affecting villus height and crypt depth. WO increased, while DO decreased, villus height in the ileum, and both forms of oats decreased crypt depth. The oat treatments failed to result in significant changes in the jejunal viscosity, although DO tended to increase this parameter. As a result of WO and DO treatments, the Lactococcus genus showed a decreasing tendency in the ileum. In conclusion, feeding WO and DO to broiler chickens results only in slight changes in the small intestine.

A feeding trial was carried out using 576 Ross 308 male chickens to test the effects of an amorphous lignocellulose (LC) product (Arbocel). Three dietary treatments (control, 0.5% LC (LC 0.5), and 0.8% LC (LC 0.8) were used, and the diets were fed in eight replicate pens of 24 chickens. The LC treatments did not modify the weight gain of the chickens, but they tended to decrease the feed intake and FCR in the grower phase. The high swelling characteristics of LC resulted in lower dry matter (DM) contents in the crop (p < 0.002) and gizzard (p < 0.047) on day 14 and day 24, respectively. The lower pH in the gizzard and duodenum of LC diets suggests longer retention time and more HCl secretion in the proventriculus and gizzard. Except for α-amylase on day 24, the treatments did not modify the digestive enzyme content of the jejunum. The microbiota diversity and microbiota composition of ileal contents were affected only by the age of birds. The results suggest that the LC product can exert its potential positive effects mainly in the upper part of the digestive tract due to its special physical characteristics. LC can slow down the passage rate in the gizzard and modify the digestion and the dynamics of water absorption from the jejunum and ileum.

This trial was carried out to find out the effects of the parent flock and hatching time of broiler chickens on the production traits and bacteriota development of animals. Two sets of 730 hatching eggs were collected from two different parent flocks with ages of 25 and 50 weeks. In the hatchery, both groups were divided into two subgroups: those hatched during the first 10 and the subsequent 10 h of the hatching window. A feeding trial was carried out afterwards, using the four treatments in six replicate floor pens and feeding commercial starter, grower, and finisher diets that contained all the nutrients according to the breeder’s recommendations. The day-old chickens of the older parent flock and those hatched later were heavier, and this advantage remained until the end of the production period. The different ages and origins of the parent flocks failed to modify the microbiological parameters of the chicken’s ceca; however, the hatching time significantly influenced the different bacteriota diversity indices: the late-hatched chickens showed higher Bacteroidetes and lower Firmicutes and Actinobacteria abundances at day 11. These treatments resulted in differences in the main families, Ruminococcaceae, Lactobacillaceae, and Bacteroidaceae. These differences could not be found at day 39.

This study shows the effects of feeding low protein (LP) diets with different energy-to-protein ratios were evaluated on the production parameters, carcass composition, meat quality, nitrogen retention, and excreta composition of broilers. A total of 576-day-old Ross 308 broilers were fed a control diet (C) and three LP diets containing 1.5% less crude protein than diet C for 41 days. The LP1 treatment was isocaloric with diet C, while the dietary apparent metabolizable energy corrected by nitrogen (AME_n) levels in the case of the LP2 and LP3 treatments were reduced by 1.5% and 3%, respectively. The LP diets were supplemented with six crystalline essential amino acids (AA) to meet the standardized ileal digestible AA requirements of broilers. The LP1 treatment did not affect the performance parameters of broilers and increased the breast meat yield, the nitrogen retention and decreased drip loss of breast meat and the total-N and uric acid-N nitrogen excretion of birds in comparison with the C group. Although the energy-reduced LP2 and LP3 diets resulted in lower final body weight, they did not affect the carcass composition, breast meat quality, nitrogen retention, and excreta composition of birds compared with the control treatment.

The medicinal plant milk thistle (Silybum marianum) has been widely used due to its hepatoprotective properties. The main objective of our study was to investigate the health protective effects of dietary milk thistle seed (MS), oil (MO), and seed cake (MSC) in ducks fed diets naturally contaminated with deoxynivalenol (DON; 3.43–3.72 mg/kg feed) and zearalenone (ZEN; 0.46–0.50 mg/kg feed). Female White Hungarian ducks were randomly allocated to four dietary treatments consisting of the control diet (C), the control diet supplemented with 0.5% MS, 0.5% MSC, or 0.1% MO. The feeding of experimental diets did not result in mortality cases, clinical signs of mycotoxicosis, or in differences of clinical chemistry values of blood serum. The positive effect of MO on vacuolar hepatocyte degeneration exceeded that of the MSC on d14 and both MS and MSC on d42. Each treatment was equally effective in the decrease of the severity of solitary cell death and infiltration of lympho- and histiocytes in the liver on d28 as well as in the prevention of lymphocyte depletion in the spleen and bursa of Fabricius on d14. In conclusion, the applied treatments have been proven effective in the prevention of histopathological changes caused by DON and ZEN.

Barley and oats can be alternatives of corn and wheat in poultry nutrition and used at higher inclusion rates. Both cereals contain hulls, a structural fiber source, that can be beneficial for the gizzard function of birds. They also contain high amounts of β-glucans, of which about 60–70% is water soluble. Soluble β-glucans increase gut viscosity, impair digestion, and modify gut microbiota. The aim of this trial was to evaluate the effects of feeding oats and barley at high inclusion rates and with exogenous glucanase on some relevant gut parameters and the microbiota composition of jejunum content (JC), jejunum mucosa (JM), and cecal content (CC). A total of 360 male, Ross 308 broiler chickens were allocated randomly into three treatment groups of 5 replicate pens with 24 chickens. Beside a corn and soybean meal-based control diet (C), a barley (B)- and oat (O)-based treatment was used. In all feeding phases, barley was fed at 40, while oats at 20% inclusion rate. At day 40, 10 birds per treatment were slaughtered and gut viscosity, the cecal short chain fatty acid (SCFA) concentration, and the microbiota composition of the different gut parts determined. In spite of the glucanase enzyme addition, the barley-based diet significantly increased the viscosity of the ileal content and this was also the diversity of the bacteriota in the small intestine. On the other hand, this treatment decreased the microbial diversity in the ceca and resulted in lower SCFA contents. Barley increased the abundance of the phyla Bacteroidetes and decreased that of Firmicutes and some of them genera in the JC and CC. Oats had only a slight effect on the measured parameters. The results highlight the importance of also taking into account the soluble fiber fractions of the feedstuffs in diet formulation and to adapt the exogenous enzyme supplementation of to the actual soluble fiber contents.

The study reported here aimed to determine whether correlations can be found between the intestinal segment-related microbiota composition and the different growing intensities of broiler chickens. The bacterial community structures of three intestinal segments (jejunum chymus—JC, jejunum mucosa—JM, caecum chymus—CC) from broiler chickens with low body weight (LBW) and high body weight (HBW) were investigated. Similar to the previous results in most cases, significant differences were found in the bacteriota diversity and composition between the different sampling places. However, fewer body weight (BW)-related differences were detected. In the JM of the HBW birds, the Bacteroidetes/Firmicutes ratio (B/F) was also higher. At the genus level significant differences were observed between the BW groups in the relative abundance of Enterococcus, mainly in the JC; Bacteroides and Ruminococcaceae UCG-010, mainly in the JM; and Ruminococcaceae UCG-013, Negativibacillus, and Alistipes in the CC. These genera and others (e.g., Parabacteroides and Fournierella in the JM; Butyricoccus, Ruminiclostridium-9, and Bilophila in the CC) showed a close correlation with BW. The co-occurrence interaction results in the JC revealed a correlation between the genera of Actinobacteria (mainly with Corynebacterium) and Firmicutes Bacilli classes with different patterns in the two BW groups. In the JM of LBW birds, two co-occurring communities were found that were not identifiable in HBW chickens and their members belonged to the families of Ruminococcaceae and Lachnospiraceae. In the frame of the co-occurrence evaluation between the jejunal content and mucosa, the two genera (Trichococcus and Oligella) in the JC were found to have a significant positive correlation with other genera of the JM only in LBW chickens.

Ammonia emission is a concern for the poultry industry from both environmental and animal welfare points of view. The objective of this research was to determine whether probiotics or wheat bran supplementation of broiler diets can modify the N composition of the excreta and the dynamics of ammonia volatilisation emission from the manure. A total of 120-day-old Ross 308 broiler chickens were fed six different diets. The treatments included a corn and soybean meal-based control diet (C) and diets containing wheat bran (WB). Both diets were fed alone and with supplementation of a lactic acid (Lactobacillus farciminis, LAB) and a butyric acid (Clostridium butyricum, BAB) producing bacterial strain. Treatment BAB had a significant effect on the dry matter content of the excreta and both probiotics decreased the amount of excreted uric acid. Treatment WB resulted in a significantly lower NH⁺₄-N concentration of excreta and a tendency toward reduced uric acid content. Treatment LAB reduced the urinary N ratio of excreta. Among dietary treatments, WB resulted in the highest urease producing cell numbers in the excreta, but this difference was not significant. Based on our results, similar to pigs, the soluble fibre fraction of poultry diets can also modify the urinary to faecal N ratio of the excreta.

In this research, the effects of early post-hatch inoculation of a competitive exclusion product (Br) and the continuous feeding of a synbiotic supplement (Sy) containing probiotic bacteria, yeast, and inulin on the production traits and composition of ileal chymus (IC), ileal mucosa (IM), and caecal chymus (CC) microbiota of broiler chickens were evaluated. The dietary treatments had no significant effects on the pattern of intestinal microbiota or production traits. The digestive tract bacteriota composition was affected mostly by the sampling place and age of birds. The dominant family of IC was Lactobacillaceae, without change with the age. The abundance of the two other major families, Enterococcaceae and Lachnospiraceae decreased with the age of birds. In the IM, Clostridiaceae was the main family in the first three weeks. Its ratio decreased later and Lactobacillaceae became the dominant family. In the CC, Ruminococcaceae and Lachnospiraceae were the main families with decreasing tendency in the age. In IC, Br treatment decreased the abundance of genus Lactobacillus, and both Br and Sy increased the ratio of Enterococcus at day 7. In all gut segments, a negative correlation was found between the IBD antibody titer levels and the ratio of genus Leuconostoc in the first three weeks, and a positive correlation was found in the case of Bifidobacterium, Rombutsia, and Turicibacter between day 21 and 40.