Effects of a mixed additive based on Saccharomyces cerevisiae and Lactobacillus rhamnosus on broilers exposed to aflatoxin B1 by contaminated feed.

The objective of the present study was to explore the influence of dietary supplementation with a mixed additive (MA) containing a probiotic and anti-mycotoxin (Saccharomyces cerevisiae RC016 and Lactobacillus rhamnosus RC007) and its interaction on the performance and health (biochemistry and liver/intestine histopathology) of broilers fed diets contaminated with aflatoxin B1 (AFB1) at 506000±22.1ng/kg. The MA contained S. cerevisiae RC016 (1×107cells/g) and L. rhamnosus RC007 (1×108cells/g) in relation 1:1. A total of sixty-one-day-old Cobb broilers were randomly allocated into four treatment groups with three replicates of 5 birds each for a five-week-old feeding experiment. The experimental diet for each treatment (T) was formulated as follows: T1, a commercial diet (CD); T2, CD+AFB1; T3, CD+0.1% MA; T4, CD+AFB1+0.1% MA. The MA improved (p<0.01) production parameters (weight gain, conversion rate, and carcass yield) and reduced (p<0.01) the toxic effect of AFB1 on the relative weight of the livers. In addition, the macro and microscopic alterations of livers and the possible intestinal injury related to histological damage in the presence of mycotoxin were reduced. The use of probiotic MA based on S. cerevisiae RC016 and L. rhamnosus RC007 in animal feed provides greater protection against mycotoxin contamination and is safe for use as a supplement in animal feed, providing beneficial effects that improve animal health and productivity. This is of great importance at the economic level for the avian production system.

Effects of dietary supplementation of cobiotic based on Agave fructans on growth performance, blood parameters, oxidative damage and immune status of broiler.

This study evaluated the effect of cobiotic (CO) composed of organic fructans powder of Agave tequilana and turmeric powder of Curcuma longa L. as an alternative of antibiotic growth promoters (AGPs) on growth performance, blood parameters, intestinal pH, oxidative stress, and cytokines serum levels of broiler chickens. A total of 135 one-day-old Ross 308 broilers distributed to five experimental groups, which included starter or finisher standard diets without AGPs (CON), CON + 0.25 COLI-ZIN g/kg feed (AGP), CON + 0.1 g Agave fructans/kg feed (AF), CON + 0.5 g turmeric powder/kg feed (TP) and CON + 0.1 g AF + 0.5 g TP /kg feed (CO), for 49 days. AF followed by TP, decreased feed intake, obtaining the best FCR. AGP increased the heterophil-lymphocyte ratio compared to other groups. CO significantly decreased the pH of the cecal content. AF increased IL-10 levels, while TP decreased it. AF decreased the IL-1ß levels. The present study showed that including a cobiotic based on AF and TP or components separately in a broilers diet improved growth performance, modified intestinal and cecum pH, and stimulated the immune system, which suggests CO as a safe alternative to AGP.

Alternative to antimicrobial growth promoters in the diets of broilers challenged with subclinical necrotic enteritis.

Necrotic enteritis (NE) is a disease of worldwide distribution, which affects young broilers and causes economic losses on a scale of 6 billion dollars per year. For decades, NE was controlled in poultry flocks by dietary administration of low doses of antimicrobial growth promoters (AGPs). However, an increase in NE incidence was noted after the AGP ban. This study aimed to compare the effect of an antibiotic (Enramycin) diet to a combination of sodium butyrate, hydrolyzed yeast, and zinc proteinate (ViligenTM) on broiler diets regarding performance, blood parameters, intestinal permeability, morphology and lesions, and carcass yield of broilers challenged with Eimeria spp. and Clostridium perfringens to simulate subclinical necrotic enteritis. A total of 1,150 one-day-old male broiler chickens with an initial average weight of 43.9 ± 0.65 g were allocated to 50 experimental pens. Animals were divided into 5 groups: Negative control (NC) without additives; Positive control (PC) with 0.12 g/ton of Enramycin (8%); V500, V1000, and V1500 with the addition of 500, 1.000, and 1.500 g/ton of Viligen, respectively. All animals were challenged by Eimeria spp. at 7 d of age and by C. perfringens at 17, 18, and 19 d for induction of subclinical NE. The broilers fed with all concentrations of Viligen showed similar performance, blood parameters, intestinal permeability, and carcass yield compared to PC broilers. However, NC broilers showed higher FCR compared to PC broilers from 1 to 33 d (1.42 vs. 1.39) (P = 0.048) and from 1 to 42 d (1.51 vs. 1.49) (P < 0.001). V1500 broilers had fewer intestinal lesions at 28 d when compared to the PC treatment (P < 0.05) and showed that higher Viligen inclusion resulted in lower intestinal damage. At 21 d, the V500 group showed higher intestinal morphology characteristics (VH:VD 4.9 vs. 3.5) compared to the PC treatment (P < 0.001). Thus, in this study, the dietary addition of Viligen to broilers challenged by an experimental model of subclinical NE resulted in lower intestinal damage and similar performance to that obtained by the addition of Enramycin.

La importancia de la microbiota intestinal en la fisiología y rendimiento de pollos de engorda y gallinas de postura / The importance of intestinal microbiota on the physiology and performance of broiler chickens and laying hens

Resumen: El estudio de la microbiota ha adquirido un nuevo enfoque de interés, ya que interviene en diversos procesos fisiológicos involucrados en el desarrollo y rendimiento de los animales domésticos. Participa en el eje-microbiota-intestino-cerebro, con procesos que rigen el sistema nervioso hacia el intestino y viceversa. El objetivo de este trabajo fue identificar la importancia de la microbiota gastrointestinal de pollos de engorda y gallinas de postura y su relación con procesos fisiológicos que afecten el desarrollo, rendimiento, comportamiento y salud. En el tracto gastrointestinal de estas aves se han identificado alrededor de 17 filos de bacterias, con microorganismos predominantes según el sitio anatómico dentro del tracto y por ende con diferente función, por ejemplo, buche: Lactobacillus, Enterobacteriaceae; proventrículo: Clostridiaceae, Enterococcus; intestino: Escherichia, Streptococcus. Distintos factores intervienen en la colonización y desarrollo de la microbiota, desde el programa de alimentación y manejo, tipo de cama y densidad animal, entre otros. Existen microorganismos potencialmente patógenos que impactan negativamente en la microbiota y puedan llegar al consumidor, como Campylobacter jejuni, Salmonella enteritidis y Escherichia coli, de ahí su importancia al momento de trazar las directrices en las producciones pecuarias.

Abstract: There is an increasing interest in microbiota studies due to their relevance in physiological processes such as animal development and productivity. In addition, it its involved in the microbiota-intestinebrain axis that regulates the nervous system to the intestine and vice versa. This paper is aimed at identifying the importance of the broilers and laying hens' gastrointestinal microbiota and its relationship with diverse physiological processes that intervene in the development, productivity, behavior, and health. There are 17 filos of bacteria within the poultry gastrointestinal tract, which are site dependent and have specific functions (Example; crop: Lactobacillus, Enterobacteriaceae; proventriculus: Clostridiaceae, Enterococcus; intestine: Escherichia, Streptococcus). In addition, different factors affect the development of microbiota such as the feeding program, handling, kind of substrate, stocking density, among others. There are several potentially pathogenic microorganisms that impact microbiota negatively and may reach the final consumer such as Campylobacter jejuni, Salmonella enteritidis and Escherichia coli. Therefore, it is important to continue supporting poultry microbiota research and areas of opportunity to improve poultry production.

Phenotypic and molecular characterisation of Salmonella spp. isolates in healthy poultry.

1. Epidemiological surveillance of Salmonella spp. serves as a primary tool for maintaining the health of poultry flocks. Characterising circulating serotypes is crucial for implementing control and prevention measures. This study conducted phenotypic and molecular characterisation of S. enterica Pullorum, S. enterica Heidelberg, and S. enterica Corvalis isolated from broiler chickens during slaughtering.2. All strains were susceptible to gentamicin, neomycin and norfloxacin. However, resistance rates exceeded 50% for ciprofloxacin and tiamulin, irrespective of the serotype. Approximately 64% of strains were classified as multidrug-resistant, with S. enterica Heidelberg strains exhibiting significantly higher overall resistance. The isolates demonstrated the ability to adhere and produce biofilm at a minimum of three temperatures, with S. enterica Pullorum capable of biofilm production at all temperatures encountered during poultry rearing.3. Each strain possessed between two and seven different virulence-associated genes. Genetic similarity, as indicated by pulsed field gel electrophoresis, exceeded 90% for all three serotypes and strains were classified in the R5 ribotype by PCR, regardless of serotype. Sequencing revealed high similarity among all strains, with homology ranging from 99.61 to 100% and all were classified to a single cluster.4. The results suggested a clonal relationship among the strains, indicating the possible circulation of a unique clonal group of S. enterica Pullorum in the southern region of Brazil.

Taste Preferences in Broilers: Effect of Age, Delivery Matrix, and Number of Chickens per Pen on Selection and Consumption Behaviour.

Due to substantial differences between studies, the understanding of avian taste perception remains incomplete. Also, studies on chicken taste preferences have mainly focused on measuring consumption differences, neglecting consumption behaviour patterns. This study investigated how age, the compound delivery matrix, and the number of birds per pen affect broiler chicken preferences and consumption behaviour, and established their preference values for four taste compounds. Ninety-six one-day-old male broiler chickens (Ross 308) were divided into two age groups (initial: days 7-23; final: days 26-42), with two compound delivery matrices (water or ground wheat) and two numbers of birds (one or two chickens per pen), following a 2 × 2 × 2 factorial design. Four taste compounds (sucrose, monosodium glutamate (MSG), L-lysine, and calcium carbonate) were tested at different concentrations. Preferences were assessed at 2, 4, and 8 h post-test, along with recording various behavioural parameters. Initial-stage birds showed higher (p < 0.001) preference values, time of approach (TA), number of bouts (NB), duration of bouts (DB), and number of pecks (NP) than final-stage birds. Birds exposed to a water matrix also exhibited higher (p < 0.001) preference and NB, while those exposed to a ground wheat matrix showed a higher (p < 0.001) NP. Pens with a pair of birds had a higher (p < 0.003) 2 h preference, TA, NB, DB, and NP, than pens with a single chicken. Chickens showed significant preference values for 100 mM sucrose at 2 h (p = 0.025), 150 mM MSG at 4 h (p = 0.026) and 8 h (p = 0.013), and 300 mM MSG at 2 h (p = 0.013). We concluded that all the variables evaluated influence broilers' taste preferences and consumption behaviour during selection tests. Future studies should prioritize including chickens in the initial stage of the production cycle, testing them in pairs or groups, and delivering compounds via a liquid matrix.

Apparent metabolizable energy and ileal amino acid digestibility of commercial soybean meals of different origins in broilers.

We studied the chemical composition and the in vivo AMEn content and apparent (AID) and standardized (SID) ileal digestibility of CP and amino acids (AA) of 27 samples of soybean meals (SBM) from Argentina (ARG), Brazil (BRA), and USA, collected in Spain. On 88% DM basis, the BRA meals had more CP (46.9 vs. 46.0 and 45.9%; P < 0.05) and less sucrose (5.21 vs. 6.28 and 6.47%; P < 0.001) and stachyose (4.20 vs. 4.66 and 4.78%; P < 0.05) than the USA and ARG meals. Urease activity, protein dispersibility index, KOH protein solubility, and trypsin inhibitor activity values, were higher for the USA meals than for the South American meals (P < 0.05). In the in vivo trial, broilers received a common crumble diet from 0 to 16 d of age and then, their respective experimental diets (53% of a N-free diet and 47% of each of the 27 SBM tested) in mash form, for 5 d. The AMEn (2,334 vs. 2,282 and 2,277 kcal/kg; P = 0.062) and the AID (87.3 vs. 86.7 and 86.4%; P = 0.054) and SID (91.9 vs. 91.2 and 90.8%; P < 0.05) of the protein, were greater for the USA meals than for the ARG and BRA meals. In fact, the SID of Lys (93.5 vs. 93.0 and 92.1%; P < 0.001) and of the sum of Lys, Met, Thr, Trp, and Cys (91.4 vs. 91.0 and 90.2%; P < 0.05) were greater for the USA meals than for the ARG and BRA meals. In summary, the chemical composition, protein quality indicators, AMEn content, and ileal digestibility of the CP and the AA of the SBM, varied with the country of origin of the soybeans. In order to increase the accuracy of the feed formulation process, the composition and nutrient content of commercial batches of SBM, by country of origin should be controlled and periodically updated.

The impact of different levels of functional oil supplementation in combination with salinomycin on growth performance and intestinal microbiota of broilers undergoing Eimeria challenge: An analysis of dynamics.

The effect of salinomycin sodium alone and in combination with functional oils on performance and microbiota of broiler infected Eimeria were evaluated. 512 broilers were randomly assigned to 4 treatments (8 replicates, 16 birds/pen): a Control group (any additives); Ionophore group: salinomycin supplementation at 66 ppm (SS66); Ionophore +0.075% Functional oil (FO) group (SS66 + FO supplementation at 750 ppm); and Ionophore +0.10% FO group (SS66 + FO supplementation at 1000 ppm). At 14 days of age, birds were gavaged with 1 mL of a saline solution containing sporulated oocysts of E. tenella, E. acervulina and E. maxima. Performance indices were measured weekly. At 28 days, intestinal content was collected for microbiota analysis. Broilers of Control group presented the worst performance indices. Broilers of Ionophore + FO (0.075% and 0.10%) groups exhibited a higher BW at 28 days of age. The supplementation of Ionophore +0.075% FO resulted in a higher relative proportion of Firmicutes and a lower proportion of Actinobacteria in the ileum-jejunum. Lactobacillaceae was the dominant family in the jejunal, and ileal microbiotas of broilers fed diets supplemented with Ionophore, Ionophore +0.075% FO and Ionophore +0.10% FO. The supplementation of ionophore yielded higher numbers of Lactobacillaceae, Enterobactereaceae and Cloritridiaceae in the cecal. Ionophore associated with FO controlled the Lactobacillaceae, Enterobactereaceae and Cloritridiaceae families present in the cecum. Therefore, the combination of salinomycin with functional oil showed synergistic effect on performance and modulation of intestinal microbiota of broilers challenged with Eimeria.

Effects of in ovo vaccination time on broiler performance parameters under field conditions.

Hatchery performance is often evaluated based on descriptors such as hatchability, 7-d mortality, and cost. In addition to these descriptors, it is useful to include in this analysis aspects of chick quality through post-hatch performance. Realizing the bird's complete genetic potential necessitates meeting various criteria, with effective support for the chick's immune system being among the pivotal factors. To be effective, in ovo vaccination systems must deliver the vaccines to specific sites in the egg, a circumstance that directly depends on when the injection is made. We examined production data to evaluate the impact of in ovo vaccination time on performance parameters of male Ross308AP chicks. A comprehensive survey was conducted examining records from 3,722 broiler flocks produced and raised by the same company under standard nutrition and management conditions. The selected data specifically pertained to flocks that underwent slaughter between 41 and 45 d. In our analysis, 4 different linear models were built, one for each response variable: mean weight (MW), body weight gain (BWG), corrected feeding conversion rate (cFCR), and total mortality (TM). The linear models used in the analyses included as main predictor the timing of in ovo vaccination (440, 444, 448, 452, 456, 458, and 460 h of incubation), and as additional predictors: age of the breeding flock (26-35, 36-55 and 56-66 wks old), slaughter age, identity of the hatchery, and the season at which the data was collected. Our results showed that the timing of in ovo vaccination significantly affected BWG and cFCR, with procedures performed at 460 h of incubation showing the best outcomes. Breeding flock age affected all response variables, with older breeding flocks delivering increased MW, BWG and TM, and middle-aged flocks increased cFCR. Increasing slaughter age reduced BWG while MW, cFCR and TM were all increased. These data emphasize the benefits of performing in ovo vaccination as close as possible to 460 h of incubation to extract the best BWG and cFCR from Ross308AP male broiler.

Multiprotease improves amino acid release in vitro, energy, and nutrient utilization in broilers fed diets varying in crude protein levels.

Low crude protein (CP) diets can reduce nitrogen (N) excretion and costs by increasing N utilization efficiency. Exogenous proteases may further improve protein digestibility in low CP diets. This study first evaluated in vitro the efficacy of a multiprotease on amino acid (AA) release from feedstuffs and broiler feed. Later, a broiler study evaluated the effect of feeding corn-soybean meal diets containing 3 CP levels (17, 19, and 21% CP) with supplementation on top of 0 or 2,400 U/kg multiprotease on chicken growth performance, total tract CP, and ileal AA digestibilities, and energy utilization. Ross 708 male chickens were placed in 42 cages and assigned to 6 treatments resulting from a 3 × 2 factorial arrangement. Three isocaloric basal diets were formulated to reduce CP, but all diets maintained digestible Lys:CP in 5.47% and the same ideal protein profile. Data were analyzed in a completely randomized design. On average, the multiprotease increased (P < 0.05) in vitro free AA release by 27.81% in most feedstuffs evaluated compared to the control. For broiler feed, 1,200 U/g multiprotease addition improved (P < 0.001) in vitro free AA release by 18.90%. This multiprotease showed interaction effects (P < 0.05) on chicken FCR, energy, and CP digestibility. As expected, BW at 24 d, BW gain, and FCR (8-24 d) worsened (P < 0.001) as dietary CP reduced from 21 to 17%, and multiprotease addition did not improve (P > 0.05) these parameters. BW gain decreased by 12.9% when N intake was reduced from 49.32 to 38.49 g/bird. Multiprotease supplementation improved (P < 0.01) AMEn by 71 kcal/kg, CP digestibility from 59.45 to 63.51%, ileal AA digestibility, and DM digestibility from 67.08 to 73.49%, but only in the 21% CP diet. No differences in ileal AA digestibility due to CP level (P > 0.05) were detected, except for Cys digestibility (P < 0.01). In conclusion, low CP diets reduced growth performance and improved N utilization but negatively affected energy utilization efficiency. Exogenous multiprotease supplementation improved AME, AMEn, protein, ileal AA, and DM digestibility in the 21% CP diet without significantly affecting growth performance.

Effects of dietary digestible amino acids and a novel exogenous sfericase protease on growth performance of broilers.

Two experiments (Exp.) were conducted to evaluate the effects of a novel exogenous sfericase protease on growth performance and ileal digestibility of broiler chickens until day 35 of age. In Exp. 1, 1350 one-day-old male chicks (Cobb 500) were allocated in 54 floor pens and fed one of the three dietary treatments, with 18 replicates of 25 birds each in a completely randomized design. Diets consisted of positive control [PC; commercially relevant ME and balanced amino acids (AA)]; negative control (NC; with reduction of 6% dig. Lys and proportional reductions for adjacent AA compared to the PC), and NC supplemented with sfericase protease [30,000 New Feed Protease units (NFP)/kg]. On day 35, ileal digesta was collected to determine apparent ileal digestibility of dry matter and nitrogen (N). In Exp. 2, 1620 one-day-old male chicks (Cobb 500) were allocated in 54 floor pens having three treatments and 18 replicates of 30 birds each in a completely randomized design from day 1-35. Broilers were fed a control basal diet (Control); Control supplemented with sfericase at 30,000 NFP/kg and at 60,000 NFP/kg. In Exp. 1, from day 1-35, body weight gain (BW gain) and feed conversion ratio (FCR) of broilers improved 3.4 and 2.5% when diets were supplemented with sfericase, respectively, whereas the digestibility of N increased by 2.7% compared to the NC. In Exp. 2, diets with usual protein and AA levels and supplemented with 30,000 NFP/kg had 2.3 and 1.75% improved BW gain and FCR from day 1-35, respectively. When diets were supplemented with 60,000 NFP/kg, BW gain and FCR were enhanced by 3.9 and 3.2%, respectively compared to the Control. In conclusion, these results demonstrate that the novel sfericase protease could be successfully used in corn-soy diets with protein and AA reductions or in feed formulations with usual digestible AA levels to enhance growth performance of broilers.

Shifts in microbiota and gene expression of nutrient transporters, mucin and interleukins in the gut of fast-growing and slow-growing chickens infected by Salmonella Enteritidis.

Slow-growing breeds are more resistant to Salmonella infection compared to fast-growing broilers. However, it is unclear whether that is associated with innate resistance or rather rely on differences in Salmonella-induced gut responses. We investigated the microbial composition and gene expression of nutrient transporters, mucin, and interleukin in the gut of a fast-growing (Cobb500) and a slow-growing naked neck (NN) chicken breeds challenged with Salmonella Enteritidis. Hatchlings were inoculated at two days of age using sterile broth (sham) or Salmonella Enteritidis (SE) and distributed according to a completely randomized design into four treatments: Cobb-sham; Cobb-SE; NN-sham; and NN-SE. Cecal SE counting and microbial composition by 16 S rRNA sequencing were determined at 24-, 96-, and 168-hours post-inoculation (hpi). Gene expression of amino acid (Asct1) and peptide transporters (PepT1), glucose transporters (Sglt1, Glut2 and Glut5) and mucin (Muc2) in the jejunum and expression of interleukins (IL1 beta, IL8, IL17 and IL22) in the cecum was assessed by qPCR at 24 and 168 hpi. NN birds were colonized by SE just as Cobb birds but showed innate upregulation of Muc2, IL8 and IL17 in comparison to Cobb. While nutrient transporter mRNA expression was impaired in SE-challenged Cobb birds, the opposite was observed in NN. There were no differences in microbial diversity at different sampling times for Cobb-SE, whereas the other groups had higher diversity and lower dominance at 24 hpi compared with 96 hpi and 168 hpi. NN birds apparently develop earlier gut microbial stability, have higher basal level of mucin gene expression as well as differential nutrient transporter and interleukin gene expression in the presence of SE which might mitigate the effects of SE infection compared to Cobb birds.

Phenotypic divergence between broiler and layer chicken lines is regulated at the molecular level during development.

BACKGROUND: Understanding the molecular underpinnings of phenotypic variations is critical for enhancing poultry breeding programs. The Brazilian broiler (TT) and laying hen (CC) lines exhibit striking differences in body weight, growth potential, and muscle mass. Our work aimed to compare the global transcriptome of wing and pectoral tissues during the early development (days 2.5 to 3.5) of these chicken lines, unveiling disparities in gene expression and regulation. RESULTS: Different and bona-fide transcriptomic profiles were identified for the compared lines. A similar number of up- and downregulated differentially expressed genes (DEGs) were identified, considering the broiler line as a reference. Upregulated DEGs displayed an enrichment of protease-encoding genes, whereas downregulated DEGs exhibited a prevalence of receptors and ligands. Gene Ontology analysis revealed that upregulated DEGs were mainly associated with hormone response, mitotic cell cycle, and different metabolic and biosynthetic processes. In contrast, downregulated DEGs were primarily linked to communication, signal transduction, cell differentiation, and nervous system development. Regulatory networks were constructed for the mitotic cell cycle and cell differentiation biological processes, as their contrasting roles may impact the development of distinct postnatal traits. Within the mitotic cell cycle network, key upregulated DEGs included CCND1 and HSP90, with central regulators being NF-κB subunits (RELA and REL) and NFATC2. The cell differentiation network comprises numerous DEGs encoding transcription factors (e.g., HOX genes), receptors, ligands, and histones, while the main regulatory hubs are CREB, AR and epigenetic modifiers. Clustering analyses highlighted PIK3CD as a central player within the differentiation network. CONCLUSIONS: Our study revealed distinct developmental transcriptomes between Brazilian broiler and layer lines. The gene expression profile of broiler embryos seems to favour increased cell proliferation and delayed differentiation, which may contribute to the subsequent enlargement of pectoral tissues during foetal and postnatal development. Our findings pave the way for future functional studies and improvement of targeted traits of economic interest in poultry.

Eggshell translucency: its relationship with specific gravity and eggshell color and its influence on broiler egg weight loss, hatchability, and embryonic mortalities.

Eggshell quality is among the most important factors affecting hatchability in broiler breeders, and therefore several methods for its assessment are available in the poultry industry. Among them, eggshell translucency has received special attention in recent years due to its connection with ultrastructural disorganization of the shell layers. However, there is very limited data on the impact of translucency on hatching eggs and on the possible links between this trait and specific gravity (SG) or shell color. Thus, our study investigated associations and interactions between eggshell translucency, SG, and color on incubation parameters of eggs from the same breeding flock (Ross 308AP, 51 wk of age). To this end, light and dark eggs within 5 different SG categories (≥1.065, 1.070, 1.075, 1.080, and ≤1.085) were selected from 15,976 eggs, graded into 3 translucency scores, and later incubated to evaluate egg weight loss, hatchability and embryonic mortalities. In general, translucency scores were evenly distributed within SG categories (χ2 [8, N = 1,138] = 13.67, P = 0.090) and color (χ2 [2, N = 1,138] = 4.93, P = 0.084). No interactions between eggshell translucency and SG or between translucency and color were found for the analyzed variables. An interaction was observed between SG and eggshell color for the variable egg weight loss, where the light-shelled eggs, in most SG categories lost more weight throughout incubation than dark eggs. Eggshell translucency affected egg weight loss, hatchability, and embryonic mortality on 11 to 18 d of incubation, with highly translucent eggs showing the worst results. At the same time, eggs with SG lower than 1.070 displayed the greatest weight loss, lowest hatchability, and highest contamination. We found no influence of eggshell color on weight loss or hatchability, but light-shelled eggs exhibited higher late embryonic mortality. Together, these data suggest that despite its effects on certain hatching parameters, shell translucency bears no relationship to SG or color.

Effects of cold stress on physiologic metabolism in the initial phase and performance of broiler rearing.

This study aimed to investigate the effects of 8 h of cold stress (18 °C) every day in broiler chicks during the first 7 days of rearing on crop filling analysis, yolk sac consumption, digestive and immune organs weights, and physiological metabolism at seven days and performance between 1 and 35 days. Cobb500 male broiler chickens (n = 274) were randomly assigned to two treatments. The treatments consisted of varying environmental temperatures during the first week post-housing. Chicks were reared at a thermoneutral temperature (32 °C) or under cold stress (18 °C) for 8 h/day during the first week, and both groups were subsequently reared at a thermoneutral temperature for 8-35 days. The thermoneutral group reached 90% full crop after 48 h of housing (P < 0.05), while the cold-stressed group had more empty crops at 2 h and 48 h after housing (P < 0.05). The chick cloacal temperature was not affected by the treatments (P > 0.05). Additionally, the treatment did not affect serum amylase and corticosterone levels, feed intake, body weight gain, or feed conversion ratio (P > 0.05, while the cold-stressed group had elevated heterophil/lymphocyte count at day 7 (P < 0.05). The thermoneutral group showed higher viability (%) at 7 and 35 days and a higher production factor at 35 days (P < 0.05). Broiler chickens under cyclic cold stress experienced decreased yolk sac absorption during the first week and increased feed intake and feed conversion ratio after 35 days of rearing. Viability was also lower in the cold-stressed group. An appropriate strategy to minimize these adverse effects is to rear the chicks in a thermoneutral environment during the first week.

Using in feed xylanase or stimbiotic to reduce the variability in corn nutritive value for broiler chickens.

This study investigated the effects of xylanase and stimbiotic (fiber fermentation enhancer) on the response of broiler chickens fed different corn varieties and determine correlations between variables of interest. Four corn genetic varieties were selected based on their range in nutrient composition. Diets containing 600 g/kg of each corn were supplemented with 0 or 100 g/ton of xylanase or stimbiotic. A total of 1,152 one-day-old male broiler chicks (Ross 308) were divided into 12 treatments, each with 8 pens and 12 birds per pen, for a 21-day study. On d 21, performance parameters were measured, and the ileal energy and organic matter (OM) digestibility and cecal xylanase activity determined. Stimbiotic supplementation improved mFCR compared with all other treatments. There was a treatment by corn variety interaction for body weight (BW), BW gain and coefficient of variation (CV) of BW (P ≤ 0.05). Birds fed corn Variety 1 (highest neutral dietary fiber, protein and soluble arabinoxylan content) supplemented with stimbiotic had the highest BW, while Variety 2 control diet had the lowest. The BW CV in corn Variety 2 was the highest, which improved with stimbiotic supplementation. The BW CV in corn Variety 1 responded better to stimbiotic than xylanase. There were no treatment differences on BW CV in corn Varieties 3 and 4. The lowest OM digestibility was observed in birds fed corn Variety 1 with xylanase, and the highest value was associated with corn Variety 3 with xylanase (highest total arabinoxylan). Xylanase and stimbiotic supplementation increased the endogenous xylanase activity regardless of the corn variety (P ≤ 0.05). Positive correlations between corn fiber contents and phytic acid and the arabinose:xylose ratio were seen, while nonstarch polysaccharide content was negatively correlated with apparent metabolizable energy. In conclusion, corn variety influenced nutrient digestibility and broiler chicken growth. The response to supplementation with xylanase or stimbiotic varied based on the nutritional profile of corn with regards to improvements in digestibility and performance in broiler chickens.

Effect of 25-hydroxycholecalciferol supplementation with different dietary available phosphorus levels for broilers.

1. Based on the hypothesis that 25-hydroxycholecalciferol (25-OH-D3) inclusion would optimise dietary mineral digestibility and ameliorate growth performance and bone mineralisation in available phosphorus (AvP) deficient-fed broilers, a trial was conducted to evaluate its effect on diets with different levels of AvP.2. Broilers aged 1-21 d were randomly assigned one of the eight treatments, consisting of four dietary levels of AvP (0.45%, 0.42%, 0.39%, and 0.36%) and with or without supplementation with 25-OH-D3 at 69 µg/kg of feed. All diets contained 100 µg/kg of vitamin D3 (cholecalciferol).3. The addition of 25-OH-D3 resulted in higher feed intake and body weight gain, and lower FCR (P < 0.05) compared to non-supplemented diets, whereas AvP levels had a quadratic effect only on feed intake. There were no interactions between treatment factors.4. Increasing AvP levels linearly reduced the ileal digestibility of Ca and P (P < 0.01) and supplementing 25-OH-D3 increased both Ca and P ileal digestibility (P < 0.05), without any interactions observed for ileal digestibility.5. There was an interaction, whereby 25-OH-D3 inclusion increased serum metabolites in broilers fed 0.36% to 0.42% AvP compared to the non-supplemented diets (P < 0.001), whereas, at 0.45% AvP, diets with or without 25-OH-D3 had similar results.6. The P content in bone linearly increased in line with AvP levels (P < 0.05) and supplementation of 25-OH-D3 increased ash bone content (P < 0.001).7. Broilers can benefit from 25-OH-D3 supplementation combined with cholecalciferol with regard to Ca and P utilisation and vitamin D status, allowing for a reduction of dietary AvP levels down to 0.36% without impairing growth performance or bone status.

Effects of 25-hydroxycholecalciferol on performance, gut health, and bone quality of broilers fed with reduced calcium and phosphorus diet during Eimeria challenge.

This study evaluated the effects of 25-hydroxycholecalciferol (25-OHD) on performance, gut health, and bone quality of broilers fed with reduced calcium (Ca) and phosphorus (P) diet during Eimeria spp. challenge. A total of 576 fourteen-day-old Cobb 500 male chicks were randomly distributed in a 2 × 2 × 2 factorial arrangement, with 6 replicates of 12 birds each. The main factors were 25-OHD level (0 or 3,000 IU/kg of feed), mineral level (0.84% of Ca/0.42% of P, the levels recommended for the grower phase (NOR) or 0.64% of Ca/0.22% of P (RED), and mid-high mixed Eimeria challenge or nonchallenge. 25-OHD improved phosphorus retention (P = 0.019), bone ash weight (P = 0.04), cortical bone trabecular connectivity (P = 0.043) during coccidiosis. For birds fed with reduced mineral levels, 25-OHD supplementation increased bone ash weight (P = 0.04). However, 25-OHD did not improve bone ash weight when birds were challenged and fed with reduced mineral levels. The dietary 3,000 IU of 25-OHD supplementation did not improve performance or gut morphology but support bone health during coccidiosis. Future investigations are needed for better understand 25-OHD role on bone microarchitecture and oxidative metabolism during coccidiosis.

In vivo analysis the effect of antibiotic growth promoters (AGPs), Oxytetracycline di-hydrate and Tylosin phosphate on the intestinal microflora in broiler chicken / Análise in vivo do efeito de antibióticos promotores de crescimento (AGPs), di-hidrato de oxitetraciclina e fosfato de tilosina na microflora intestinal em frangos de corte

The study was aimed to analyse the effects of antibiotic growth promoters (AGPs), Oxytetracycline di-hydrate and Tylosin phosphate on the intestinal microflora in broiler chicken. The AGPs were provided in different concentrations solely or in combinations for 42 days of rearing. Faecal samples were collected from the intestine (duodenum, jejunum and caeca) of broiler chicken on 14th, 28th and 42nd days of trial. Samples were cultured on different selective medium and bacterial identification was performed by different biochemical and molecular diagnostic tools. Results showed a significant effect of AGPs on the growth of pathogenic microorganisms such as Escherichia coli and Clostridium perfringens in the intestine. Interestingly, an impaired growth was observed for both bacterium showing a significant effect (P<0.05) of AGPs on E. coli and C. perfringens on day 14th, 28th, and 42nd. This effect was observed solely and in combination while using AGPs. Data further showed that the effect was more prominent in combination and with an increase concentration of AGPs. Remarkably, no impairment was seen on the growth of L. reuteri at different sites of intestine and duration (14th, 28th, and 42nd days). The results showed that the use of AGPs in diet has no harmful effect on beneficial bacteria, however, an impaired growth was seen on the harmful bacteria. It is suggested that a combination of AGPs (OXY-1.0+TP-0.5) is economical and have no harmful effect on the broiler chicken. The use of AGPs in a recommended dose and for a specific period of time are safe to use in poultry both as growth promoter and for the prevention of diseases.

O estudo teve como objetivo analisar os efeitos dos antibióticos promotores de crescimento (AGPs), di-hidrato de oxitetraciclina e fosfato de tilosina na microflora intestinal de frangos de corte. Os AGPs foram fornecidos em diferentes concentrações isoladamente ou em combinações por 42 dias de criação. Amostras fecais foram coletadas do intestino (duodeno, jejuno e ceco) de frangos de corte no 14º, 28º e 42º dias de ensaio. As amostras foram cultivadas em diferentes meios seletivos e a identificação bacteriana foi realizada por diferentes ferramentas de diagnóstico bioquímico e molecular. Os resultados mostraram um efeito significativo dos AGPs no crescimento de microrganismos patogênicos como Escherichia coli e Clostridium perfringens no intestino. Curiosamente, um crescimento prejudicado foi observado para ambas as bactérias, mostrando um efeito significativo (P <0,05) de AGPs em E. coli e C. perfringens nos dias 14, 28 e 42. Este efeito foi observado apenas e em combinação com o uso de AGPs. Os dados mostraram ainda que o efeito foi mais proeminente em combinação e com um aumento da concentração de AGPs. Nenhum comprometimento foi observado no crescimento de L. reuteri em diferentes locais do intestino e duração (14º, 28º e 42º dias). Os resultados mostraram que o uso de AGPs na dieta não tem efeito nocivo nas bactérias benéficas, no entanto, foi observado um crescimento prejudicado nas bactérias nocivas. Sugere-se que uma combinação de AGPs (OXY-1.0+TP-0.5) seja econômica e não tenha efeito prejudicial sobre o frango de corte. O uso de AGPs em uma dose recomendada e por um período de tempo específico é seguro para uso em aves tanto como promotor de crescimento quanto para prevenção de doenças.

Stevia as a natural additive on gut health and cecal microbiota in broilers.

Stevia mash (SM), leaves of Stevia rebaudiana Bertoni plant, is an additive used in poultry that enhances growth and health. Objective: to determine the effect of 1 % SM on productive parameters, gut health, and the cecal microbiome in broilers between the first 15 and 21 days old. One hundred sixty male, 1-day-old broilers (48.5 ± 2.5 g) were divided into Control (C) without SM and Treated (T) with 1 % SM on diet, during 15/21 days. Each subgroup had eight broilers/five repetitions/treatment. At day 15 or 21, all broilers were dissected, Fabricius Bursa and Gut removed and processed for histomorphometry, followed by Villi Height/Crypt Deep (VH/CD) ratio. Conversion Index (CI) was determined. The V3-V4 region of 16S rRNA gene was amplified from DNA obtained from pooled cecal contents and sequenced on Illumina Miseq PE 2 × 250 platform. Sequence processing and taxonomic assignments were performed using the SHAMAN pipeline. Both T groups have better VH/CD Ratios than C groups (p ≤ 0.05). In guts, increased plasmatic and goblet cells number and thicker mucus layer were found in T15 and T21. All groups received SM showed early immunological maturity in Fabricius Bursa. IC was similar between all treatments. Faecalibacterium, Ruminococcus torques group, and Bacteroides were the major genera modulated by SM addition. At 15 and 21 days old, SM exerts a impact on diversity and evenness of the cecal microbiome.  Conclusion: SM (1 %) produced early immunologic maturity on Fabricius Bursa, increased intestinal functionality, and modified the microbiota, increasing beneficial microbial genera and microbial diversity.