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 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.

The objective of this research was to determine whether diet composition, or adding probiotic or symbiotic feed additives to broiler diets can modify the N composition of the excreta and the dynamics of ammonia volatilization from the manure. A total of 574 one-day-old Ross 308 broiler chickens were fed four different diets. The treatments included a corn and soybean meal-based control diets (C), wheat-based and wheat bran containing diets (W), a multi-strain probiotic treatment (Broilact^®; Br), and a symbiotic additive containing Bacillus subtilis, inulin, and Saccharomices cerevisiae (Sy). Feeding the wheat-based diet significantly improved the weight gain and FCR of chickens. Treatment W also significantly increased the dry matter content of the excreta compared with the probiotic and symbiotic treatments. Both Br and Sy tended to decrease the amount of excreted uric acid, which is the main substrate of ammonia. Treatment Sy reduced the urinary N ratio of the excreta in comparison with treatment W. The symbiotic additive resulted in significantly higher ammonia emission in the first two hours. On the other hand, the dynamics of the emission was slow at the beginning and increased steeply after 15 h when the wheat-based diets were fed. Based on our results, the wheat-based diets, containing soluble arabinoxylans, and the symbiotic treatments of broiler diets have an impact on the urinary and faecal nitrogen composition of the excreta, and also on the dynamics of ammonia release from the manure.

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 use of locally available protein sources in poultry nutrition is challenging for feed manufacturers and farmers. Sunflower meal (SFM) is available in high quantities in several European countries and could be used as a poultry feedstuff at higher inclusion rates. However, its maximum inclusion rate in the diets of different poultry species and age categories is unknown. Pullets and laying hens can probably tolerate higher amounts of SFM, but only limited information is available on these poultry groups. Therefore, a digestibility trial was carried out with 8-week-old layer type pullets and 50-week-old laying hens. Beside a basal diet, SFM was fed at 10, 20 and 30% inclusion rates. Feeding SFM significantly improved the digestibility of essential amino acids (AA) of threonine, valine, lysine, tyrosine, glycine, aspartic acid, and arginine in the pullet diets. No such improvement was found in laying hens. Only the absorption of the two branch-chain AAs, leucin (pullets) and isoleucine (hens), declined due to SFM. The AA digestibility of the SFM itself was also calculated by linear regression. The coefficients were, in all cases, higher in hens than in pullets. Comparing the measured digestibility coefficients of SFM with table values, it can be concluded that high variance exists because of the differences in the methodology and the test animals in the digestibility trials. From the present trial, it can be concluded that SFM can entirely replace extracted soybean meal in pullet and layer diets, without negative effects on the protein digestion of birds.