Poultry Diets Research Articles

Iron nanocysteinates in diets with activated feed for meat-based chickens

The results of evaluating the effect of different sizes of iron cysteine nanoparticles as an alternative to using inorganic iron in poultry diets to ensure mineral balance are presented. It has been established that replacing the inorganic salt FeSO4·7H2O with iron nanocysteinate of 20 and 100 nm in size in the diets of meat-egg chickens has a positive effect. The live weight of young animals in the group using iron nanocysteinate with a particle size of 20 nm exceeded the control by 33.3% and 100 nm by 31.6%. Using iron nanocysteinate with a particle size of 300 nm decreased the indicator by 17.5%. The combined use of activated grain and chelates increases poultry productivity. Thus, the average daily increases were higher by 8.6 – 10.7 – 19.5% for the compared experimental groups. Over the 40 days of raising chickens on activated feed, the average live weight in the control was 552.0 g. The addition of iron nano chelates increased indicators in the 6th and 7th groups by 148 and 156 g, respectively, or by 21.2 and 22.0%. At the same time, in group 8, chickens were stunted in growth compared to the control and groups 6–7, where the particle sizes of iron nanocysteinate were 20 and 100 nm. Iron chelates' role in forming average daily growth on non-activated and activated backgrounds is identical and varies between 3.2–3.4 g in groups 2 and 3; 6 and 7. When comparing similar pairs of groups raised on non-activated and activated feeds with the same addition of iron nanocysteinate, the indicators were higher in young poultry growing on activated feed: groups 2 and 6 - by 8.6%; 3 and 7 – by 10.7%; 4 and 8 – by 19.5%.

Dietary Inclusion Level Effects of Yoghurt Acid Whey Powder on Performance, Digestibility of Nutrients and Meat Quality of Broilers.

In recent years, the increasing demand for Greek strained yoghurt produced massive amounts of acid whey, which constitutes a major environmental pollutant. Whether yoghurt acid whey can be included in poultry diets is not known. The purpose of this study was to evaluate the effects of four dietary levels of yoghurt acid whey powder (YAWP) on the growth performance, nutrient digestibility, meat quality traits and oxidative stability. A total of 300 male 1-day-old Ross 308 broilers were assigned into four groups with five replicates of 15 broilers each: control-fed basal diet with no YAWP addition (WO) or basal diet supplemented with YAWP at 25 g/kg of diet (WA), 50 g/kg of diet (WB), or 100 g/kg of diet (WC). At the starter period, body weight and body weight gain were reduced after WB and WC treatments compared to the WO treatment. Breast meat oxidative stability was improved during refrigerated storage for 1 and 3 d in all YAWP treatments compared to control, while the WA treatment showed an improved oxidative stability after 6 and 9 d. The results suggest that YAWP inclusion at 25 g/kg of diet did not impair performance and extended the meat shelf life by reducing lipid oxidation rates.

Application of multi-omic features clustering and pathway enrichment to clarify the impact of vitamin B2 supplementation on broiler caeca microbiome.

The results of omic methodologies are often reported as separate datasets. In this study we applied for the first time multi-omic features clustering and pathway enrichment to clarify the biological impact of vitamin B2 supplementation on broiler caeca microbiome. The caeca contents of broilers fed +50 and +100 mg/kg vitamin B2 were analyzed by shotgun metagenomic and metabolomic. Latent variables extracted from NMR spectra, as well as taxonomic and functional features profiled from metagenomes, were integrated to characterize the effect of vitamin B2 in modulating caeca microbiome. A pathway-based network was obtained by mapping the observed input genes and compounds, highlighting connected strands of metabolic ways through pathway-enrichment analysis. At day 14, the taxonomic, functional and metabolomic features in the caeca of tested broilers showed some degree of separation between control and treated groups, becoming fully clear at 28 days and persisting up to 42 days. In the caeca of birds belonging to the control group Alistipes spp. was the signature species, while the signature species in the caeca of broilers fed +50 and +100 mg/kg vitamin B2 were Bacteroides fragilis and Lactobacillus crispatus, Lactobacillus reuteri, Ruminococcus torques, Subdoligranum spp., respectively. The pathway enrichment analysis highlighted that the specific biochemical pathways enhanced by the supplementations of vitamin B2 were N-Formyl-L-aspartate amidohydrolase, producing Aspartate and Formate; L-Alanine:2-oxoglutarate amino transferase, supporting the conversion of L-Alanine and 2-Oxoglutarate in Pyruvate and L-Glutamate; 1D-myo-inositol 1/4 phosphate phosphohydrolase, converting Inositol 1/4-phosphate and water in myo-Inositol and Orthophosphate. The results of this study demonstrated that the caeca of birds fed +50 and + 100 mg/kg were those characterized by taxonomic groups more beneficial to the host and with a higher concentration of myo-inositol, formic acid, amino acids and pyruvate involved in glycolysis and amino acid biosynthesis. In this study we demonstrated how to perform multi-omic features integration to describe the biochemical mechanisms enhanced by the supplementation of different concentrations of vitamin B2 in the poultry diet. The relationship between vitamin B2 supplementation and myo-inositol production was highlighted in our study for the first time.

Influence of two levels of phytic acid and particle size of oyster shell on the performance, calcium digestibility, gastrointestinal pH, and bone traits in broilers

ABSTRACT 1. Phytic acid (PA) is an antinutritional factor in poultry diets. The effect of high dietary PA in chicken diets might be exacerbated when the particle size of oyster shell (OS) is too fine. Thus, this study investigated the hypothesis that high PA with fine OS particle size would impair growth in broilers. 2. Two hundred and eighty Cobb 500 broilers were assigned to four diets in a 2 × 2 factorial arrangement in a CRD. The factors were PA (low or high) and OS particle size (fine or coarse) in starter, grower and finisher diets. Data collected were performance, Ca digestibility, gastrointestinal pH and bone traits. 3. On d 21, high PA increased intake (P < 0.05), gain (P = 0.099) and body weight (BW; P = 0.093) compared to low PA. On d 42, high PA increased BW (P = 0.086) and gain (P = 0.089) compared to low PA. High PA increased intake (P = 0.063), BW (P = 0.054) and gain (P = 0.056) compared to low PA on d 56. High PA improved liveability on d 56 (P < 0.05) compared to low PA. In birds fed coarse OS, crop and ileal pH were reduced (P < 0.05) by high PA on d 28. The OS × PA interaction was observed for ileal pH (P < 0.05) on d 56, where in birds fed coarse OS, low PA increased ileal pH. Fine OS increased crop (P = 0.056) and proventriculus pH (P < 0.05) on d 56. There were no treatment effects on calcium digestibility. In birds fed fine OS, high PA decreased the BS (P < 0.05). 4. Overall, the study showed that a combination of high PA and coarse OS particle size improves the production performance of broilers, while low PA and coarse OS improve their bone health.

Antioxidant Properties and Toxic Risks of Using Metal Nanoparticles on Health and Productivity in Poultry

Metal nanoparticles (NPs) are introduced into various fields of science, particularly poultry farming. Supplementation of metal salts in nanoform can increase the profitability of poultry farming by enhancing meat and egg production. Although their toxic parameters pose limitations on their use, many studies have evaluated the effects of using metal NPs in modern poultry farming on health, productivity, metabolism, and especially antioxidant properties. In addition, the peculiarities of their toxicokinetic and recommended doses that meet safety criteria in practical activities are highlighted. Zinc oxide NPs are one of the most studied compounds in the poultry industry. Their pronounced antioxidant properties, positive effect on productivity and homeostasis of poultry, egg quality, and immune status have been experimentally confirmed. Copper oxide NPs have similar properties but are limited in usage due to their toxicokinetics. Silver and gold NPs emerge as potential alternatives to antibiotics and could solve the resistance problem of microorganisms to antibiotics. Other important NPs used in poultry are Iron and Calcium. In their nanoform, these NPs exhibit high bioavailability, which allows for efficient absorption and utilization by poultry. The methods used to synthesize these nanoparticles make it economically viable to incorporate them into poultry diets, reducing overall expenses compared to similar macroergic compounds. Manganese and chromium NPs positively affect sperm survival in turkeys during refrigerated storage and contribute to increasing the resistance of the broiler chickens' body to heat stress and normalizing the metabolism of sex hormones. In conclusion, the application of metal nanoparticles to poultry is a promising research direction, aiming at the development of feed additives, antibiotics, and growth stimulants due to their antioxidant, bactericidal, and immunomodulatory effects.

Effect of Nano-selenium on exosomes secretion associated with sperm maturation within the epididymis

Selenium is commonly used as a supplement in the poultry diet and plays an important role in male fertility. However, the effect of selenium nanoparticles (Se-NPs) on exosome secretion associated with spermatozoa in the epididymis is largely unknown. H&E staining, Immunohistochemistry, Immunofluorescence and Western blot were performed to study the effect of Se-NPs on exosomes secretion associated with sperm maturation in epididymis. The results indicated that the Se-NPs showed a significant contribution to sperm concentration by light microscopy. It was observed that there was an increase in the spermatozoa concentration in the epididymis of the treated group as compared to the control group. Furthermore, exosome secretion, the expression of tumor susceptibility gene-101 (TSG-101) and cluster of differentiation (CD-63) proteins was identified by immunochemistry, immunofluorescence assay, and western blotting. After nano-selenium treatment, the exosome markers TSG-101 and CD-63 were strong positive immunoreactivity and immunosignaling in the lumen followed by epithelial lining of the epididymis. However weak positive immunoreactivity and immunosignaling were seen of TSG-101 and CD63 in the control group. In addition, highly significant protein expression of TSG-101 and CD63 in the treated group as compared to the control group was confirmed by western blotting. In conclusion, the above findings provide rich evidence about the Se-NPs play a dynamic role in exosome secretion that might be essential for sperm motility and maturation within epididymis.

Evaluation of probiotic growth stimulation using prebiotic ingredients to optimize compounds for in ovo delivery.

The use of probiotics, prebiotics and synbiotics in poultry diets beneficially stimulates the gut microbiome thus promoting the health and welfare of the animals. In this study, we analyzed 7 poultry probiotics (Lactobacillus plantarum - B1 and B4, Lactobacillus rhamnosus - B3, Bifidobacterium lactis - B2, Carnobacterium divergens - B5, Propionibacterium thoenii - B6, Clostridium butyricum - B7) and 12 prebiotics, differing in chemical composition and source of origin (fungi, algae, animal, etc.). The main goal of our research was to select the most promising candidates to develop synbiotic combinations. We determined the growth kinetics of all probiotics in the presence of prebiotics in a series of in vitro studies to select optimal combinations. Five out of seven investigated probiotics were significantly stimulated by astragalus polysaccharide, and this prebiotic was characterized in our work as the most effective. Moreover, in the case of three probiotics, B2, B3 and B4, significant growth stimulation has been found when beta-glucan, vegetable protein hydrolysate and liquid seaweed extract were supplied. Strain B1 (L. plantarum) was stimulated by 6 out of 12 prebiotics. The growth of B4 (L. plantarum) and B2 (B. lactis) was enhanced by prebiotics after 2 h of incubation. A high growth rate of 3.13% was observed in the case of L. plantarum (B4) and a 3.37% higher rate for B. lactis (B3), compared to the growth of probiotics in the control medium with glucose but no prebiotics. The best candidates for synbiotic combinations based on this in vitro work are the strains belonging to L. plantarum (B4), L. rhamnosus (B3) and B. lactis (B2), consistent with prebiotics such as astragalus polysaccharides and vegetable protein hydrolysate. These combinations will be subject to future in vivo poultry trials involving the in ovo microbiome modulation.

Defatted Black Soldier Fly Larvae Meal as an Alternative to Soybean Meal for Broiler Chickens

The production of soybean meal (SBM) has a substantial impact on the environment and reducing its inclusion in poultry diets by using alternative protein sources, such as insect meal, is an important challenge for nutritionists. This study aimed to compare the productive performance of broiler chickens fed one of two isonitrogenic (195 g/kg CP) and isocaloric (12.91 MJ/kg) diets. The first diet contained SBM as the main protein source, whereas SBM was completely replaced by defatted meal from Black Soldier Fly larvae (Hermetia illucens L.; BSFL) in the second diet. Compared to the BSFL diet, the final body weight (BW) and weight gain (WG) of birds fed the SBM diet was ~17% greater and feed was utilised 19% more efficiently (p &lt; 0.05). The differences in WG and FCR were supported by improved energy metabolism metrics, fat digestibility and digestibility of acid detergent fibres (ADFD) (p &lt; 0.05). The present study shows that a complete replacement of dietary SBM with BSFL meal must be achieved with care, ensuring that all other factors (e.g., insect processing technology, feed additive supplementation, non-protein nitrogen accounting, mineral balance, fatty acid profile, amino acid supplementation) have been considered.

Protein Replacers in Poultry Diets

The experiment was conducted in a private poultry farm from 20/9/2021 to 24/10/2021. Four hundred eighty chickens of the Ross 308 strain were used; the chicks were randomly divided into 5 experimental groups. Several plant protein sources in Iraq were used as the major protein source instead of soya bean meal to cover the diet requirement for protein and calories. The following characteristics were studied: average live body weight gain, feed and CP utilization efficacy, and chemical and calculated physiological fuel value for boneless meat at 6 weeks of age. Keywords: Protein, poultry diets, poultry industry

Effects of Dietary Supplementation of a Resin-Purified Aqueous-Isopropanol Olive Leaf Extract on Meat and Liver Antioxidant Parameters in Broilers.

Olive leaves are byproducts οf the agro-industrial sector and are rich in bioactive compounds with antioxidant properties. They could be supplemented in poultry diets powdered or less frequently as extracts to improve performance, health and product quality. The objective of this study was to investigate the possible beneficial effects of an aqueous isopropanol olive leaf extract-purified through filtration (250-25 µm) and a resin (XAD-4)-when supplemented in broiler chickens' diets, on meat quality parameters, focusing mainly on antioxidant parameters as there is limited published information. For this purpose, four-hundred-and-eighty-day-old broilers were randomly assigned to four dietary treatments: T1 (control: basal diet); T2 (1% olive leaf extract); T3 (2.5% olive leaf extract); T4 (positive control: 0.1% encapsulated oregano oil commercially used as feed additive). At the end of the experimental period (day 42), the birds were slaughtered, and samples from breast, thigh meat and liver were collected for antioxidant parameters evaluation. On day 1, after slaughter, in thigh meat, Malondialdehyde (MDA) was lower in T2 compared to T3, and total phenolic content (TPC) was higher in T2 compared to T3 and T4. Total antioxidant capacity (TAC) was increased in T2 and T4 breast meat compared to the control. In liver, T4 treatment resulted in higher TPC. The lack of dose-dependent effect for olive leaf extract may be attributed to the pro-oxidant effects of some bioactive compounds found in olive leaves, such as oleuropein, when supplemented at higher levels. In summary, it can be inferred that the inclusion of 1% olive leaf extract in the feed of broilers has the potential to mitigate oxidation in broiler meat and maybe enhance its quality.

PRODUCTION OF PHYTASE BY ASPERGILLUS TERREUS AND EVALUATING ITS STABILITY

Secretory capacity of fungi, Aspergillus terreus (A. terreus), for phytase production is up to the mark. Soil samples containing A. terreus (n=20) were randomly collected in sterile plastic zipper bags, and recognized microscopically and morphologically to screen for phytase production. In the present study, A. terreus phytase production was quantified by providing different physical conditions i.e. temperature and pH to get their optimum level. Thermal stability was obtained by measuring stability at temperature range of 35°C, 55°C, 75°C, and 95°C, whereas, pH stability was estimated at intervals of 2h, 4h, 6h, and 8h. Chemical stability of phytase was judged by analyzing the effects of common earth crust metal ions such as Na+1, K+1, Ba+2, Ca+2, Cu+2, Mg+2, Mn+2, and Fe+3. Phytase production was assessed on phytase screening medium to observe the zone of hydrolysis. The highest phytase production was given by sample 16 (PAST-16) which was; 271.49 ± 8.14 units/mL (FTU/mL) and the lowest was given by sample 3 (PAST-3); 92.15 ± 5.53 FTU/mL. Temperature induced reduction in phytase enzyme and the highest reduction was noted at 95°C for 1 hour and the lowest reduction was recorded at 35°C for 15 min. Moreover, acidic pH (pH=2) induced more reduction for 1 hour exposure than high pH (pH=6) for 15 min. All metal ions, at their high concentration, adversely affected the phytase activity of A. terrus and Cu+2 showed the maximum reduction in phytase. Thus, the present study explored the physico-chemical stability of fungal phytase that can be used in poultry diet as a cheapest source of digestibility improving agent

Lipid sources and emulsifiers in Japanese quail diets as modulators of performance, egg quality and yolk fatty acid profile

Abstract Using emulsifiers in poultry diets may increase digestibility of alternative lipid sources and enrich poultry egg yolks altering their fatty acid composition. This study aimed to evaluate performance, nutrient digestibility, egg quality, egg quality according to their storage period, and the fatty acid profile of Japanese quail egg yolk (Coturnix coturnix japônica). The design was completely randomized, in which 270 female quails were allocated in a 3x2 factorial diet arrangement: three lipid sources (soybean oil, poultry fat, and beef tallow), supplemented or not with an emulsifier, following two nutritional strategies – a diet formulated to meet the nutritional requirements proposed by INRA and a diet formulated with a reduction of 96 Kcal/kg of feed and added emulsifier. The effects of interactions between the lipid sources and the emulsifier were studied, their isolated effects when interactions were absent and the effect of storage time, and their interactions with the factors evaluated for egg quality variables. Feed intake was greater when beef tallow was added to the diets, while feed conversion was worse for birds fed diets with soybean oil and the emulsifier. Quails fed the diet with the emulsifier and soybean oil produced better quality eggs represented by the higher Haugh unit. Diets with beef tallow and poultry fat provided a higher percentage of palmitic and unsaturated fatty acids in the quail egg yolk. Alternative lipid sources such as beef tallow and poultry fat can be used as a substitute for soybean oil with added emulsifiers in diets for egg-laying quails without impairing performance and egg quality. The use of emulsifiers with alternative lipid sources to soybean oil can be considered a nutritional strategy in laying quail diets, but the reduction of energy in the diet must be adequate for the species.

Traditional and Non-Traditional Feeds in Poultry Feeding: A review

Quite a few nations have a thriving poultry feed sector. This essay focuses on Feed, which is regarded as the most expensive component of poultry production. Feed processing also raises the price of feed, in addition to the cost of ingredients. The population of the world is projected to rise to 9.1 billion people by the year 2050. Meat and egg consumption from chicken is rising worldwide, primarily in developing nations. As a result, there would be a rise in the demand for poultry feeds worldwide. Due to their significance in improving the general health of birds, additives in poultry feeding are nowadays a need in any product of factories making feedings. Nowadays, especially in emerging nations, the supply of feeds for chicken nutrition is becoming increasingly competitive. The use of alternative feedstuffs to replace soybean and yellow corn in poultry diets and the alternative feedstuffs that can be used in poultry feeds are both being pursued. Additionally, the availability of nutritional content and methods for enhancing the nutritive quality of such nontraditional feedstuffs.

Influence of multienzyme drugs in the diets of broiler chickens on their hematological parameters

In order to intensify modern poultry farming, close attention is paid to breeds, crosses with high growth potential. The poultry diet should be balanced in terms of metabolic energy and protein due to the inclusion of several ingredients and additives. Specialists of the agro-industrial complex have accumulated a large amount of research on the eff ective use of biologically active drugs in poultry farming. The use of enzyme drugs contributes to an increase in the level of energy nutrition, as well as accelerated growth and development of farm animals and poultry. The purpose of our work was to improve of production traits and hematological parameters in broiler chickens when using diff erent multi enzyme drugs in their diets. A scientifi c and economic experiment was carried out on broiler chickens of the cross Ross 308 under the conditions of a poultry farm of the IP Fitisov G. N., village Ozerny in the Caucasian district of the Krasnodar Territory. The broilers of the 1st control group received wheat and corn compound feed. The following multi enzyme drugs were additionally included in the diet of chickens of the experimental groups: the 2nd experimental group – Natugrain TS 100 g/t of compound feed, the 3rd experimental group – Rovabio Excel AP 50 g/t of compound feed, the 4th experimental group – Ronozim Multigrain 125 g/t of compound feed, the 5th experimental group – Akstra HV 100 g/t of compound feed, 6th experimental group – Akstra HAR 100 g/t of compound feed, 7th experimental group – Hostazim Combi 100 g/t of compound feed, 8th experimental group – Vilzim 20 g/t of compound feed and 9th experimental group – Enzyme Complex 750 g/t compound feed. The conditions of housing and feeding for broiler chickens of the experimental groups were the same and corresponded to the zoo and hygienic requirements for housing and feeding poultry. The use of multi enzyme drugs in compound feed for broiler chickens allowed us to increase live weight by 4,76–13,87 %, reduce expenditures of feed per unit of live weight gain by 4,73–12,43 %. The inclusion of multi enzyme drugs in the formula of compound feed allowed us to improve blood parameters. For example, there was an increase in the number of red blood cells, total protein, calcium, phosphorus and a decrease in the number of white blood cells. Thus, the introduction of multi enzyme drugs into compound feed for broiler chickens had a positive effect on the productive indicators of poultry and also on morphological and biochemical parameters of blood.

Insects as an alternative protein source for poultry nutrition: a review.

This review summarizes the most relevant scientific literature related to the use of insects as alternative protein sources in poultry diets. The black soldier fly, the housefly, the beetle, mealworms, silkworms, earthworms, crickets, and grasshoppers are in the spotlight because they have been identified as an important future source of sustainable animal proteins for poultry feeding. Insect meals meet poultry requirements in terms of nutritional value, essential amino acid composition, nutrient digestibility, and feed acceptance. Furthermore, they are enriched with antimicrobial peptides and bioactive molecules that can improve global health. Results from poultry studies suggest equivalent or enhanced growth performances and quality of end-products as compared to fish meal and soybean meal. To outline this body of knowledge, this article states established threads of research about the nutrient profiles and the digestibility of insect meals, their subsequent effects on the growth and laying performances of poultry as well as the quality of meat, carcass, and eggs. To fully exploit insect-derived products, the effects of insect bioactive molecules (antimicrobial peptides, fatty acids, and polysaccharides) were addressed. Furthermore, as edible insects are likely to take a meaningful position in the feed and food chain, the safety of their derived products needs to be ensured. Some insights into the current knowledge on the prevalence of pathogens and contaminants in edible insects were highlighted. Finally, the effect of insect farming and processing treatment on the nutritive value of insect larvae was discussed. Our overview reveals that using insects can potentially solve problems related to reliance on other food sources, without altering the growth performances and the quality of meat and eggs.

Growth performance and physiological responses of broilers fed Stylosanthes hamata leaf meal in a hot tropical environment.

Forage plants are considered an essential source of vitamins, protein and energy and could decrease the intake of the conventional diets by up to 10% if young quality forage plants are offered and about 7% of a broiler's daily protein needs and 3% of their daily calorie needs can be met by pasture. However, there is a paucity of data on the quantification of the herbage intake in broiler chickens. This trial was designed to determine the performance and physiological response of broilers fed diets containing Stylosanthes hamata leaf meal (SHLM) at 0%, 1%, 5%, 10%, 15% and 20% inclusion (weight for weight) in a basal diet of poultry. Two hundred and forty-day-old Arbor Acres broiler chicks were used for this trial. They were allocated at random to each of the 6 dietary treatment groups with 4 replicates of 10 chickens each. The study lasted for 35 days, during which data were collected weekly. Results indicated no difference (p>0.05) in body weight gain, feed consumption and feed conversion ratio of broiler chickens across all ages. Although the plasma triiodothyronine (T3 ) concentration of the birds was influenced at the sixth week of age, there was no consistency in the trend. At the eighth week of age, chickens on 15% SHLM had significantly (p<0.05) higher cortisol (3.22ng/mL) concentrations compared to 10% (3.13ng/mL) and 20% (3.16ng/mL) SHLM treatment groups. Treatment groups, regardless of the age of the chickens, had similar (p>0.05) mean plasma creatinine values. The study concluded that SHLM could be incorporated into broiler feed up to 20% without a deleterious impact on physiology and performance indices.

Uncovering the effects of copper feed supplementation on the selection of copper-tolerant and antibiotic-resistant Enterococcus in poultry production for sustainable environmental practices

The use of antibiotics in animal production is linked to the emergence and spread of antibiotic-resistant bacteria, a threat to animal, environmental and human health. Copper (Cu) is an essential element in poultry diets and an alternative to antibiotics, supplementing inorganic or organic trace mineral feeds (ITMF/OTMF). However, its contribution to select multidrug-resistant (MDR) and Cu tolerant Enterococcus, a bacteria with a human-animal-environment-food interface, remains uncertain. We evaluated whether feeding chickens with Cu-ITMF or Cu-OTMF contributes to the selection of Cu tolerant and MDR Enterococcus from rearing to slaughter. Animal faeces [2–3-days-old (n = 18); pre-slaughter (n = 16)] and their meat (n = 18), drinking-water (n = 14) and feed (n = 18) from seven intensive farms with ITMF and OTMF flocks (10.000–64.000 animals each; 2019–2020; Portugal) were sampled. Enterococcus were studied by cultural, molecular and whole-genome sequencing methods and Cu concentrations by ICP-MS. Enterococcus (n = 477; 60 % MDR) were identified in 80 % of the samples, with >50 % carrying isolates resistant to tetracycline, quinupristin-dalfopristin, erythromycin, streptomycin, ampicillin or ciprofloxacin. Enterococcus with Cu tolerance genes, especially tcrB ± cueO, were mainly found in faeces (85 %; E. faecium/E. lactis) of ITMF/OTMF flocks. Similar occurrence and load of tcrB ± cueO Enterococcus in the faeces was detected throughout the chickens' lifespan in the ITMF/OTMF flocks, decreasing in meat. Most of the polyclonal MDR Enterococcus population carrying tcrB ± cueO or only cueO (67 %) showed a wild-type phenotype (MICCuSO4 ≤ 12 mM) linked to absence of tcrYAZB or truncated variants, also detected in 85 % of Enterococcus public genomes from poultry. Finally, < 65 μg/g Cu was found in all faecal and meat samples. In conclusion, Cu present in ITMF/OTMF is not selecting Cu tolerant and MDR Enterococcus during chickens' lifespan. However, more studies are needed to assess the minimum concentration of Cu required for MDR bacterial selection and horizontal transfer of antibiotic resistance genes, which would support sustainable practices mitigating antibiotic resistance spread in animal production and the environment beyond.

Dietary supplementation of microalgae mitigates the negative effects of heat stress in broilers

Heat stress in poultry is a serious concern, affecting their health and productivity. To effectively address the issue of heat stress, it is essential to include antioxidant-rich compounds in the poultry diet to ensure the proper functioning of the redox system. Microalgae (Spirulina platensis) are rich in antioxidants and have several health benefits in humans and animals. However, its role in health and production and the underlying mechanism in heat-stressed broilers are poorly understood. This study aimed to determine the effect of microalgae supplementation on the health and production of heat-stressed broilers. Cobb500 day-old chicks (N=144) were raised in litter floor pens (6 pens/treatment and 8 birds/pen). The treatment groups were: 1) no heat stress (NHS), 2) heat stress (HS), and 3) heat stress+3% microalgae (HS+MAG). The broilers in the HS+MAG group were fed a diet supplemented with 3% microalgae, whereas NHS and HS groups were fed a standard broiler diet. Broilers in the NHS were raised under standard temperature (20°C-24°C), while HS and HS+MAG broilers were subjected to cyclic heat stress from d 22 to 35 (32°C-33°C for 8 h). Heat stress significantly decreased the final body weight, whereas the supplementation of microalgae increased the final body weight of broilers (P < 0.05). The expressions of ileal antioxidant (GPX3), immune-related (IL4), and tight-junction (CLDN2) genes were increased in microalgae-supplemented broilers compared to heat-stressed broilers (P < 0.05). The ileal villus height to crypt depth ratio was improved in microalgae-supplemented broilers (P < 0.05). In addition, microbial alpha, and beta diversities were higher in the HS+MAG group compared to the HS group (P < 0.05). There was an increase in volatile fatty acid-producing bacteria at the genus level, such as Ruminococcus, Ocillospira, Lactobacillus, Oscillobacter, Flavonifractor, and Colidextribacter in the group that received microalgae supplementation. In conclusion, dietary supplementation of microalgae improved the growth performances of heat-stressed broilers by improving their physiogenomics. Thus, the dietary inclusion of microalgae can potentially mitigate heat stress in broilers.

Review on application of probiotics in poultry farm

Poultry farming, raising of birds domestically or commercially, primarily for meat and eggs but also for feathers. In poultry industry, probiotics applications have widely been shown to improve the barrier function of intestine and reduce pathogenic problems in gastrointestinal tract thus leading to the enhancement of immune response and replacement of sub-therapeutic antibiotics. Probiotics, the novel feed or food supplements are naturally occurring beneficial live microbes including bacteria, fungi and yeasts. Probiotics are proven to improve the health and wellbeing of birds. As a group of growth promoters, the addition of probiotics to the diet of poultry has been found to improve growth performance, feed conversion efficiency, immune responses and help in combating enteric pathogens. The addition of probiotics to poultry diet also improves egg production in layers. Three basic mechanisms of probiotics include competitive exclusion of pathogenic microbes, production of antibacterial substances and immune modulation of host. Generally, live a pathogenic microbial strain, singly or as multistrain probiotics, belonging to genus Lactobacillus, Streptococcus, Bacillus, Enterococcus, Pediococcus, Aspergillus and Saccharomyces are used in poultry. The injudicious and prolific use of sub-therapeutic levels of antibiotics in animal feed to suppress or eliminate harmful organisms, and to improve growth and feed efficiency, have paved way for their presence as residues in animal by-products and have also given rise to drug resistant microorganisms. Because of public health concerns, nowadays, the use of probiotics as substitute for antibiotics in poultry production has become an area of great interest. The present article reviews the beneficial effects and potential applications of probiotics or direct fed microbial (DFM) on health and production performances in poultry.

Growth performance, intestinal morphometry, and blood serum parameters of broiler chickens fed diets containing increasing levels of wheat bran with or without exogenous multi-enzyme supplementation during the grower and finisher phases

In developing countries, wheat bran (WB) is extensively used in poultry diets. However, it contains non-starch polysaccharides. The use of exogenous enzymes increases the digestibility of this feed ingredient. The objective of the study was to investigate the effects of multi-enzyme (XGP) on the growth performance, intestinal morphometry, and blood-serum parameters of broilers fed diets containing increasing levels of WB. A total of 720 Cobb 500 seven-day-old straight-run chicks (average BW = 156 ± 0.95 g) were randomly assigned to one of eight dietary treatments with six replicates each. A 2 × 4 factorial design, with two levels of XGP (0 or 360 g/ton) and four levels of WB (0, 4, 8, or 12%) was used. BW, ADG, ADFI, and FCR were determined at 14, 28, and 42 days. Birds were euthanized on day 42 for hematological and morphological measurements. There was a WB × XGP interaction for BW (P = 0.032) and ADG (P = 0.040) but not for ADFI or FCR at 42 d of age driven mainly by the inclusion level of WB. In addition, the main effects of WB or XGP inclusion did not influence ADFI of broilers. However, the overall FCR improved with XGP inclusion while increasing WB level linearly (P = 0.003) increased it. XGP × WB (P = 0.036) was observed for villi height (VH), villi height to crypt depth ratio (VH: CD), and high-density lipoprotein cholesterol (HDCL) but not for other blood parameters. These interactions were attributed to both the level of WB and XGP addition to the diets. Besides, the addition of XGP decreased blood serum cholesterol, red blood cells, white blood cells, hemoglobin, and hematocrit. Thus, the WB level did not have any adverse effect on feed intake but linearly increased the overall BW, ADG, and FCR of broilers. However, enzyme addition improved overall FCR and increased broiler VH, VH: CD, and HDCL while decreasing blood serum cholesterol. In conclusion, supplementing wheat bran diets with multi-enzyme improved FCR, increased blood serum HDCL, and decreased cholesterol.