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This study aimed to perform a meta-analysis to combine genetic parameters for economically important traits of Iranian indigenous chickens. A data set of information related to different growth, reproduction, and egg quality traits including 336 heritability estimates and 433 genetic correlations from 45 articles published between 2007 and 2019 were used. Meta-analysis was performed based on a random-effects model to calculate the effect size for genetic parameters. Also, statistic and Q test were used to measure the degree of heterogeneity among studies. The mean heritability for growth traits ranged from 0.222 (body weight at hatch) to 0.34 (body weight at 12 weeks of age). The lowest and highest estimates of the heritability for reproductive traits were 0.181 (number of eggs produced) and 0.449 (age at sexual maturity), respectively. The mean heritability estimate for egg internal quality traits varied from 0.211 (yolk weight) to 0.355 (albumin weight) and for external quality traits of eggs in the range from 0.261 (shell strength) up to 0.332 (Shell weight). Also, the mean genetic correlation estimates between growth traits, and between reproductive traits ranged from 0.297 to 0.878 and -0.678 to 0.788, respectively. Also, the genetic correlation between internal and external quality traits of eggs ranged from -0.069 to -0.979 and -0.012 to -0.856, respectively. The estimates reported in the present study are appropriate to be used in breeding programs when reliable genetic parameter estimates are not accessible for economically important traits in native fowls.

This study aimed to perform a meta-analysis to combine genetic parameters for economically important traits of Iranian indigenous chickens. A data set of information related to different growth, reproduction, and egg quality traits including 336 heritability estimates and 433 genetic correlations from 45 articles published between 2007 and 2019 were used. Meta-analysis was performed based on a random-effects model to calculate the effect size for genetic parameters. Also, I² statistic and Q test were used to measure the degree of heterogeneity among studies. The mean heritability for growth traits ranged from 0.222 (body weight at hatch) to 0.34 (body weight at 12 weeks of age). The lowest and highest estimates of the heritability for reproductive traits were 0.181 (number of eggs produced) and 0.449 (age at sexual maturity), respectively. The mean heritability estimate for egg internal quality traits varied from 0.211 (yolk weight) to 0.355 (albumin weight) and for external quality traits of eggs in the range from 0.261 (shell strength) up to 0.332 (Shell weight). Also, the mean genetic correlation estimates between growth traits, and between reproductive traits ranged from 0.297 to 0.878 and -0.678 to 0.788, respectively. Also, the genetic correlation between internal and external quality traits of eggs ranged from -0.069 to -0.979 and -0.012 to -0.856, respectively. The estimates reported in the present study are appropriate to be used in breeding programs when reliable genetic parameter estimates are not accessible for economically important traits in native fowls. [ABSTRACT FROM AUTHOR]

ABSTRACT The objective of this study was to compare the antimicrobial activity of macrophages and serum in laying hen (MM, CC, and CCc) and broiler chicken lineages (TT and LL). Macrophages were evaluated for phagocytic and antimicrobial activity. Microbicidal serum activity was evaluated by the resistance test for serum and the agar test. The results showed that phagocytic activity was higher in males of the MM strain, with 13% of macrophages presenting phagocytosis, while the other lineages studied, and even female MM, presented a rate of 6% of phagocytic cells. However, antimicrobial activity in macrophages from males of CCc lineage and females of TT lineage were higher, eliminating more than 30% of the Salmonella enterica inoculum, while in the other strains, the results were similar, with inoculum reduction below 30%. In the serum resistance assay, female laying lines presented higher antibacterial activity than female broiler lines. In the trials to evaluate the microbicide activity of the serum, females of both broiler and laying lineages presented higher performance when compared with males of the same lineage. Females of laying hen lines (MM and CC) present a greater antibacterium activity than males. These results can contribute to a better understanding of the immune response in broiler chicken and laying hen lineages, to aid development of lineages of birds more resistant to pathogens.

Objectives: To characterize and compare resistance trends in clinical Escherichia coli isolates from humans, food-producing animals (poultry, cattle and swine) and pets (dogs and cats).Methods: Antibiogram results collected between January 2014 and December 2017 by MedQual [the French surveillance network for antimicrobial resistance (AMR) in bacteria isolated from the community] and RESAPATH (the French surveillance network for AMR in bacteria from diseased animals) were analysed, focusing on resistance to antibiotics of common interest to human and veterinary medicine. Resistance dynamics were investigated using generalized additive models.Results: In total, 743 637 antibiograms from humans, 48 170 from food-producing animals and 7750 from pets were analysed. For each antibiotic investigated, the resistance proportions of isolates collected from humans were of the same order of magnitude as those from food-producing animals or pets. However, resistance trends in humans differed from those observed in pets and food-producing animals over the period studied. For example, resistance to third-generation cephalosporins and fluoroquinolones was almost always below 10% for both humans and animals. However, in contrast to the notable decreases in resistance observed in both food-producing animals and pets, resistance in humans decreased only slightly.Conclusions: Despite several potential biases in the data, the resistance trends remain meaningful. The strength of the parallel is based on similar data collection in humans and animals and on a similar statistical methodology. Resistance dynamics seemed specific to each species, reflecting different antibiotic-use practices. These results advocate applying the efforts already being made to reduce antibiotic use to all sectors and all species, both in human and veterinary medicine. [ABSTRACT FROM AUTHOR]

Background: Antimicrobial usage (AMU) in livestock plays a key role in the emergence and spread of antimicrobial resistance. Analysis of AMU data in livestock is therefore relevant for both animal and public health.Objectives: To assess AMU in 470 broiler and 252 turkey farms of one of Italy's largest poultry companies, accounting for around 30% of national poultry production, to identify trends and risk factors for AMU.Methods: Antimicrobial treatments administered to 5827 broiler and 1264 turkey grow-out cycles in 2015-17 were expressed as DDDs for animals per population correction unit (DDDvet/PCU). A retrospective analysis was conducted to examine the effect of geographical area, season and prescribing veterinarian on AMU. Management and structural interventions implemented by the company were also assessed.Results: AMU showed a 71% reduction in broilers (from 14 to 4 DDDvet/PCU) and a 56% reduction in turkeys (from 41 to 18 DDDvet/PCU) during the study period. Quinolones, macrolides and polymyxins decreased from 33% to 6% of total AMU in broilers, and from 56% to 32% in turkeys. Broiler cycles during spring and winter showed significantly higher AMU, as well as those in densely populated poultry areas. Different antimicrobial prescribing behaviour was identified among veterinarians.Conclusions: This study evidenced a decreasing trend in AMU and identified several correlates of AMU in broilers and turkeys. These factors will inform the design of interventions to further reduce AMU and therefore counteract antimicrobial resistance in these poultry sectors. [ABSTRACT FROM AUTHOR]

Objectives: Characterization of non-Escherichia coli NDM-carrying Enterobacteriaceae in the poultry production environment.Methods: A total of 36 NDM-positive Enterobacteriaceae (22 Klebsiella pneumoniae, 13 Enterobacter cloacae and 1 Salmonella enterica) were isolated from a chicken farm and WGS was conducted using Illumina Hiseq2500. The genomic characterization of the isolates acquired through WGS analysis included the genomic context-flanking blaNDM genes, MLST, the antibiotic resistance genes (ARGs) and replicon types of plasmids. WGS information for another 73 K. pneumoniae isolates from different sources was retrieved from GenBank and then combined with isolates in this study for comparative genomic and phylogenetic analysis.Results: Three types of genetic environment carrying blaNDM were identified in 36 non-E. coli Enterobacteriaceae isolates. Sequence comparison analysis indicated these genetic environments were completely identical to our previous findings. WGS further revealed three major types of plasmids (IncFIB, IncX3 and IncFII) from these isolates and the phylogenetic analysis suggested several K. pneumoniae isolates with ST11, ST37 and ST147 from the commercial chicken farm that were closely related to isolates of human origin.Conclusions: The blaNDM-harbouring genetic contexts were identified not only in E. coli, but also in K. pneumoniae, E. cloacae and S. enterica, which may indicate that blaNDM has been widely disseminated to non-E. coli Enterobacteriaceae species in animal farms. The close relationship of K. pneumoniae isolates from different origins suggests they could serve as a key vehicle for the transfer of ARGs between humans and food animal production environments. [ABSTRACT FROM AUTHOR]

Aves, chickens, epiphysial cartilage, osteogenesis, united states department of agriculture, science of nutrition, physiology, fowls, domestic, poultry meat, professors. [Extracted from the article]

The cloacal bursa is an organ in fowls, which triggers lymphocyte maturation and transference to other tissues. Since there is scanty information on its morphology in wild species in spite of its importance in the fowls´ immunological system, current analysis describes the arterial vascularization of the cloacal bursa in the greater rhea. Twenty juvenile rheas (male and female), which died of natural causes, were obtained from the Center for the Multiplication of Wild Animals (CEMAS/UFERSA). The animals were dissected and their thoracic aorta cannulated and red-stained Latex Neoprene 650 was introduced. The cloacal bursa was irrigated from the terminal branches of the abdominal aorta similar to the caudal mesenteric artery and to the right and left internal iliac arteries. The right and left internal pudenda arteries originated from the right and left internal iliac arteries which, in their turn, gave rise to cloacal-bursa arteries and to the right and left cloacal arteries in all studied animals. The caudal mesenteric artery contributed to the arterial blood of the cloacal bursa in almost all studied animals through the anastomosis of right or left internal pudenda artery, with direct branches to the cloacal bursa. The cloacal bursa of the greater rhea is irrigated by cloacal-bursa arteries and cloacal right and left and also by the mesenteric caudal artery, with small variations with regard to the number and layout of the anastomoses and branches from the arteries. The latter are specific characteristics and differentiate them from standards perceived in other fowls.

Eight wild fowls kept in captivity at a Brazilian Zoo were examined from july 1994 to October 2000. One hundred twenty-three Ixodidae specimens were collected and sent to the Ixodides Laboratory at the Instituto Oswaldo Cruz, Rio de Janeiro, Brazil. They were examined by stereomicroscopy and were identified as Amblyomma longirostre (53), A. pacae (50), A. cajennense (14), and A. parvum (6).

Molecular genetic selection on individual genes is a promising method to genetically improve economically important traits in chickens. The polymorphism in the intron I of chicken growth hormone (cGH) gene was investigated in the Iraq native fowls by using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. The genomic DNA was extracted .l from 95 samples (47 from the Black feather native fowls and 48 from the Nicked neck native fowls) by using modified salting out technique. The DNA fragment of the growth hormone gene with 770 bp was amplified by PCR using specific primers. Then the PCR products were digested with MspI restriction enzyme and analyzed on 1.5% agarose gel. The allelic frequency of intron 1 locus for A and B alleles in Iraq native fowls (Black feather) were 0.47 and 0.53 and those in Nicked nick native fowls were 0.46 and 0.54, respectively. The results of current study indicated that the intron 1 of cGH is polymorphic in Iraq native fowls and could be exploited as a candidate gene for marker-assisted I selection for growth-related traits. [ABSTRACT FROM AUTHOR]

Two experiments to determine nutritional requirements of crude protein (CP) for leghorn laying hens and brown laying hens during the first productions phase (19 to 29 weeks old) were carried out, in order to assess and establish the crude protein effect on laying hens under premontane humid forest conditions. Three hundred Hy-Line W-36® hens were used in the first experiment and 200 Hy-Line Brown® hens were used in the second one, distributed in an experimental complete randomized design (CRD), with five treatments, five repetitions and 12 "Hy line W36" fowl and 8 "Hy line Brown" fowl per experimental unit. The fowl were fed with a basic corn diet and soybean meal, with 2800 kcal ME/kg and five CP levels (14, 15, 16, 17 and 18%). Statistic differences (P>0.05) were not found in the egg production variables, feed conversion, food intake, eggs per housed fowl and feces dampness both in leghorn brown laying hens. Meanwhile, the production peak age decreased with the increase in the protein level in leghorn laying hens, while the weight profit increased with the growing levels of CP. It's possible to feed leghorn and brown laying hens in premontane humid forest conditions with 14 to 17% CP levels, in order to obtain good eggs production, provided that fowls are given the daily quantity of essential and limiting aminoacid and a gain of suitable body weight is maintained. [ABSTRACT FROM AUTHOR]

Abstract: Our objective was to identify temperature-related risk factors associated with the colonization of broiler-chicken flocks with Campylobacter spp. in Iceland, with an underlying assumption that at minimum ambient temperatures, flies (Musca domestica) play a role in the epidemiology and seasonality of Campylobacter. At slaughter, pooled caecal samples were obtained from 792 flocks that hatched between March 15 and September 15 each year from 2001 to 2004, and cultured for Campylobacter. Daily temperature data (average, maximum and minimum temperatures) were obtained from the Icelandic Meteorological Office. We determined the closest weather station to each farm using ArcGIS 9. We then used logistic-regression models (with a random-effects term for farm) to examine associations between flock positivity and temperature-related predictors. The overall prevalence of Campylobacter was 27.4%, and the month with the highest prevalence (54.4%) was August. The final model included cumulative degree-days (CDD) above an average temperature of 4.4°C and the presence of 1 or more days below a maximum temperature of 8.9°C (threshold below which fly activity was expected to be substantially reduced and egg laying was not expected to occur) during the period 2–4 weeks (i.e. days 8–28) before slaughter. Below 79 CDD, the risk of flock Campylobacter colonization was generally low. Between 79 and 139 CDD, the risk increased gradually, but was lower for flocks raised during periods with 1 or more days <8.9°C than flocks raised without days <8.9°C. The risk increased sharply under conditions of high CDD (>139) and when the maximum temperature remained >8.9°C during the period 2–4 weeks before slaughter. [Copyright &y& Elsevier]

An experiment was carried out to study the effect of changes in either the quality or the quantity of dietary protein intake on the free essential amino acid profiles in plasma, muscle or liver of growing chickens. Following a randomized paired-feeding design based on metabolic body weight (kg M0·75), White Rock male broilers were allocated to one of three isoenergetic (14·5 kJ metabolizable energy per g dry matter (DM)) semisynthetic diets containing different levels of protein (60, 120, 180 or 240 g/kg DM). All diets were based on soya-bean meal, as the sole source of protein, either unsupplemented (diets S) or supplemented with 20 g/kg L-lysine (diets SL) or 2 g/kg DL-methionine (diets SM). Samples of blood, biceps muscle and liver were taken and amino acid analysis was determined by high performance liquid chromatography. Plasma was only adequate to detect the effect of the supplementation with methionine to balance the dietary amino acid (AA) profile. Plasma concentrations of free methionine significantly increased as a result of the supplementation with methionine (P < 0·001) and remained unaffected by the amount of protein ingested. When lysine was added to diets S to induce an AA imbalance, a significant increase in muscle concentrations of free valine, isoleucine and phenylalanine (P <0·05) and a significant decrease in liver concentrations of free arginine and phenylalanine were observed (P<0·05). The supplementation with DL-methionine gave rise to a significant fall in the concentrations of free histidine, glycine and threonine (P < 0·05) and increased those of isoleucine and methionine in the skeletal muscle (P < 0·05), while in liver it significantly lowered the concentrations of free arginine, valine, leucine, phenylalanine and methionine (P < 0·001 to P < 0·05) and raised that of free glycine (P < 0·001). The ratios lysine: phenylalanine, lysine: valine and methionine: glycine in muscle together with that of methionine: glycine in liver seem to be appropriate indexes of the adequacy of the dietary AA profile to requirements. [ABSTRACT FROM PUBLISHER]

An experiment was carried out to study the effect of changes in either the quality or the quantity of dietary protein intake on the excretion of nitrogen (N) compounds in the chicken. Thirty-two White Rock male broilers (1 day old) were raised in batteries and fed a commercial starter diet for 9 days. Then they were randomly divided into eight groups each of four birds, of similar body weight (mean live weight: 178 (s.e. 1·9) g), and individually housed in metabolism cages. Following a paired-feeding design based on metabolic body weight (kg M0·75), each group of birds was given, for an experimental period of20 days, each of four levels of protein (60, 120, 180 or 240 g/kg: 5 days each) in two groups of isoenergetic (14·5 kj metabolizable energy per g dry matter) and semisynthetic diets based on soya-bean meal, known to be first limiting in methionine, either unsupplemented (diets S) or supplemented with 2 g/kg DL-methionine (diets SM). Excreta were collected every 3 days for 48 h, frozen and stored at −20°C. The excreta samples were subjected to chemical analysis for uric acid by a rapid high-performance liquid chromatographic method, for urea and ammonia by a colorimetric method, and for total N by the Kjeldahl procedure. In general, the excretion of major N compounds was markedly affected by either the quality or the content of dietary protein. Overall, the excretion of total N, uric acid-N, ammonia-N and urea-N significantly (P < 0·05) decreased with improvement in dietary protein quality and significantly (P < 0·05) increased with increase in protein intake. Regression equations were obtained relating the excretion of uric acid, urea, ammonia and total N on protein supply. For the partition ofN compounds output, the ratios of uric acid-N and ammonia-N to total N significantly (P < 0·05) decreased on improving dietary protein quality and increased or remained unchanged, respectively, with the increase in dietary protein content. The use of the ratio of ammonia-N to total N is recommended as a rapid, easy and accurate indicator of dietary protein adequacy, as an alternative to measures based on total N balance, without the need for separation of urine and faeces. [ABSTRACT FROM PUBLISHER]

Background Antimicrobial resistance (AMR) in foodborne pathogens of animal origin, including nontyphoidal Salmonella (NTS), is a public health concern. Pennsylvania conducts integrated surveillance for AMR in NTS from human and animal sources in collaboration with the FDA and CDC National Antimicrobial Resistant Monitoring System (NARMS). Methods We reviewed pulsed-field gel electrophoresis (PFGE), antimicrobial susceptibility (SST) and whole-genome sequencing (WGS) data for isolates from animal and food sources, including 96 NTS from 2,520 meat samples (poultry, ground beef and pork chops) purchased during 2015–2017 from randomly selected retail outlets in Pennsylvania. SST to 15 antimicrobial agents was done on 109 NTS clinical isolates that had similar PFGE patterns to meat isolates. SST and WGS were used to characterize all isolates from meat and two clinical isolates from 2017. Results 28 (29.2%) and 17 (17.7%) NTS isolated from meat sources were resistant to ≥3 and ≥5 antibiotics classes, respectively. Resistance to ceftriaxone rose from 12% (3/25) in 2015 to 27% (10/37) in 2016 and resistance to amoxicillin/clavulanate also increased. Plasmid-mediated bla CMY-2 β-lactam resistance genes that hydrolyze extended-spectrum cephalosporins (ESC) increased from 12% in 2015 (3/25) to 18.9% (7/37) in 2016. Four blaCTX-M-65 genes that confer resistance to extended-spectrum β-lactamases (ESBLs) were identified in 2016 (n = 3) and 2017. Of the 109 clinical isolates, 25.7% demonstrated resistance to ≥3 and 11% to ≥5 antibiotics classes, respectively. No clinical isolates were resistant to ceftriaxone in 2015, 12.5% (6/48) and 24.3% (9/37) were resistant in 2016 and 2017, respectively. Resistance to amoxicillin/clavulanate was demonstrated in 8.3% (4/48) of isolates in 2016 (figure). Two clinical isolates carried blaCTX-M-65 ESB Ls genes and were resistant to eight antimicrobial agents (ACSSuTCxNalCot. Phenotype). Conclusion NTS (≥25%) from animal and human sources were multidrug-resistant and harbored CMY-2 and CTX-M-65 genes. Dissemination of genes that confer resistance to ESBLs and ESCs in NTS undermines recommended treatment for severe infections and underscores the need for One-Health surveillance and antimicrobial stewardship efforts. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]