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PubMed1988

Pattern of vascular canals in the bone extremities of the pelvic appendicular skeleton in broiler type fowl.

Broiler fowls were reared from hatching till 20 weeks old. Birds were killed throughout the growth period and the bone extremities of the pelvic appendicular skeleton prepared for study. The patterns of vascular canals in these broiler fowls were very similar to earlier reports in laying strain fowls. There was a great range of and variation in the vascular morphology of broiler fowl. The physeal vasculature of the rapidly growing broilers was frequently disrupted, and such areas were often associated with dyschondroplastic lesions. The rapidly growing bone extremities in broiler fowls were susceptible to occlusion of epiphyseal vascular canals. lesions were frequently seen at similar sites in different specimens. Links are suggested between the growth rate, weight and behavioural characteristics of broiler fowls and the development of lesions.

Animals↗

PubMed1984

[Poultry meat production with varying densities in raising the broilers].

Tests were carried out at two densities of raising the broilers on productional premises--16.6 and 23.6 per 1 m2 of flooring. Both the prophylactic programme and the conditions of tending and feeding were one and the same on the premises used. Each one of these was supplied with a cell in which birds were kept at the same density value as that on the other premise. Thus, four groups were formed in all: I--broilers kept at the rate of 16.6 per sq. m, II--broilers raised on the premise at 23.6/m2, III--broilers kept in a cell at 16.6 on the same premise where the other birds were kept at 23.6, and IV--broilers kept at 23.6 per sq. m. on the premise where the rate concerning the other birds was 16.6. The basic integral indices of the production effectiveness as well as the bioconversion of the dietary amino acids were followed up. It was found that during the transitional period the lower productional results with the broilers raised at higher densities were due to the action of biotic factors, and, more specifically, to the changes in the homotypical reactions that were the result of the higher density of raising. In the summer season the pesimal effect produced was a complex one, including not only the biotic factors but also the unfavourable action of the temperature and humidity regime.

Amino Acids↗

PubMed1981

[Microbiological studies of slaughterhouse broilers].

Studied were a total of 187 broilers after the completion of their slaughter processing, with special reference to the correlation between the weight and the quality of the slaughtered birds and their bacterial contamination. It was found that with the increase in the weight of the slaughtered and processed broilers the total bacterial count with them progressively dropped. The quality of the slaughtered broilers was found to correlate with their bacterial contamination. Least contaminated were broilers of first quality, and the broilers of second quality and those that were not standard were 2.2 and 19.6 times more strongly contaminated, respectively. The microbiologic study of slaughtered broilers varying in weight and quality revealed that the count of coliforms was highest followed by that of the proteolytic organisms and staphylococci.

Abattoirs↗

PubMedDate not supplied

Effect of formaldehyde exposure in the hatcher and of ventilation in confinement facilities on broiler performance.

Broiler embryos and chicks were exposed to formaldehyde vapors (up to 130 ppm) during the final 3 days of incubation. Bacterial load was significantly lower in a formaldehyde-fumigated hatcher than in an unfumigated hatcher. Hatchability was not affected. To determine if exposure to formaldehyde vapors in the hatcher would affect broilers' ability to tolerate variations in air quality, chicks were placed in either adequately or poorly ventilated confinement facilities for 45 days. Total and respirable dust particles (< or = 5 microns in diameter) increased to a greater extent between 5 and 6 weeks of broiler age in the poorly ventilated facility than in the facility with adequate ventilation. Mortality at 6 weeks of age was significantly higher in broilers exposed to formaldehyde in the hatcher and housed with poor ventilation than in broilers exposed to formaldehyde and raised with adequate ventilation. Six-week body weight, feed conversion, and septicemia/toxemia condemnations were adversely affected by poor ventilation. This study found that the quality of air in the confinement facility had a greater influence on broiler productivity than did exposure to formaldehyde vapors in the hatcher.

Aerosols↗

PubMed1997

Influence of dietary L-carnitine on performance and carcass quality of broiler chickens.

Effects of dietary L-carnitine supplementation on the performance, carcass yield and components, abdominal fat and composition of meat of broiler chickens were investigated. Ross broiler chicks, 18-day-old were used in this experiment. Four experimental diets were formulated, by adding three levels of supplemental L-carnitine (50, 100 or 150 mg/kg) to a basal diet and used from 18 to 46 days of age. Apart from the level of supplementation, L-carnitine (CN) addition resulted in significant increases (P < 0.05) in body weight gains (BWG) of broilers (means were 397 vs. 365 and 410 vs. 377 g, for the first and second weeks of the experimental period, respectively). Abdominal fat (AF) contents of 46-day-old broilers were significantly decreased, both as absolute weights (P < 0.05) and as percentages of body weight (P < 0.01), by added CN (means of AF were 36.8 vs. 44.8 g, equivalent to 1.87 vs. 2.32%). Level of added CN had no effect on BWG or AF of broilers. It was concluded that the effectiveness of supplemental L-carnitine for improving BWG and/or decreasing AF of broilers may depend on the age at which L-carnitine is added. Under the conditions of this study, a supplementation of 50 mg L-carnitine per kg diet proved to be effective.

Adipose Tissue↗

PubMed2002

Spatial and temporal variation of the intestinal bacterial community in commercially raised broiler chickens during growth.

The objective of this study was to determine whether host, compartment, or environmental specific factors play an important role in the establishment of the intestinal microflora in broiler chickens during growth. This objective was addressed using a 16S rDNA approach. PCR-amplicons from the V6 to V8 regions of the 16S rDNA of intestinal samples were separated by denaturing gradient gel electrophoresis (DGGE). The number of bands in all intestinal compartments increased when broilers grew older, indicating that the dominant bacterial community becomes more complex when chickens age. Each chicken had a unique banding pattern for all locations in the intestinal tract, irrespective of the age of chickens. This suggests that host-related factors affect the establishment of the dominant bacterial community. Banding patterns of intestinal compartments within one chicken were different from each other for broilers older than 4 days, except for both ceca which were highly similar. In 4-day-old broilers, banding patterns from crop, duodenum, and ileum were very similar. We conclude that (unknown) host specific factors play an important role in the development of the intestinal bacterial community in each broiler chicken. Furthermore, compartment-specific factors play an important role in the bacterial development of each intestinal compartment within one chicken.

Animals↗

PubMed2006

Acute heat stress induces oxidative stress in broiler chickens.

The stress responses and possible oxidative damage in plasma, liver and heart were investigated in broiler chickens acutely exposed to high temperature. Eighty 5-week old broiler chickens were exposed to 32 degrees C for 6h. The extent of lipid peroxidation, activities of superoxide dismutase and total antioxidant power in plasma, liver and heart tissues were investigated. Meanwhile, the blood metabolites such as glucose, urate, triiodothyronine, thyroxine, corticosterone, ceruloplasmin and creatine kinase were measured before and after 3 and 6h of heat exposure. The results showed that oxidative stress could be induced in 5-week old broiler chickens by acute heat exposure (32 degrees C, 6h). The results suggest that the elevated body temperature can induce the metabolic changes that are involved in the induction of oxidative stress. The liver is more susceptible to oxidative stress than heart during acute heat exposure in broiler chickens. The oxidative stress should be considered as part of the stress response of broiler chickens to heat exposure.

Animals↗

PubMed2005

Role of cochlear integrity in cochlear nucleus glucose metabolism and neuron number after cochlea removal in aging broiler chickens.

In the chicken auditory system, cochlear nucleus (nucleus magnocellularis, NM) neurons receive their only excitatory input from the ipsilateral cochlea. Cochlea removal (CR) results in an immediate decrease in NM neuron electrical activity, followed by death of approximately 30% of NM neurons. Previous work showed a decrease in NM activity and subsequent loss of NM neurons in all chicks. Egg layer adults showed NM neuron loss after CR, while neuron number remained stable in broiler adults. This suggested that effects of CR on NM were age- and breed-dependent. We now know that most aging egg layer chickens maintain largely normal cochleae throughout adulthood. Some exhibit cochlear damage with age. The converse is true of broiler chickens. Most aging broiler chickens display cochlear degeneration, with some maintaining normal cochlear anatomy throughout adulthood. The presence of extensive cochlear damage may alter the effect of CR on NM, leading to the described differences. Here, we examine the effect of unilateral CR on NM glucose metabolism and neuron number in 2, 30, 39, and 52 week-old broiler chickens found to have normal cochleae. Chickens with damaged cochleae were excluded. Using 2-deoxyglucose uptake to evaluate bilateral NM glucose metabolism, we found significantly decreased uptake ipsilateral to CR at each age examined. Bilateral cell counts revealed significant neuron loss ipsilateral to CR at each age examined. This suggests that NM glucose metabolism decreases and subsequent neuron death occurs in aging broiler chickens when a normal cochlea is removed. The status of the cochlea must play a role in the effect of deafferentation on NM glucose metabolism and neuron survival. The effect of CR appears to be dependent upon neither age nor breed, but upon cochlear integrity instead.

Aging↗

PubMed2005

A quantitative risk assessment of the public health impact of the Finnish Salmonella control program for broilers.

In order to study the public health effects of the Finnish Salmonella control program (FSCP), a quantitative risk assessment model of Salmonella from slaughtered broiler flocks to consumers was developed. Based on the model, approximately 0.21% of domestically produced broiler meat mass was contaminated with Salmonella (95% probability interval 0.05-0.48%). This model was combined to the model on primary production of broilers. By this way, the effect of eliminating breeder flocks from production which have tested positive for Salmonella and heat-treating the meat of detected positive broiler flocks on public health could be simulated. Based on the whole model, if detected positive breeder flocks were not removed this would result in 1.0-2.5 more reported human cases compared to the expected number of cases under current FSCP (95% predictive interval). Without heat treatment of meat the increase would be 2.9-5.4-fold and without both interventions 3.8-9.0-fold. In scenarios with one grandparent or five parent flocks infected, the combined effect of these two interventions was 9.3-25.8-fold and 4.9-11.7-fold compared to the baseline level under each scenario, respectively. The scenario analyses suggest that with a higher infection level, inclusion of both interventions will be more effective than either of the interventions alone. Replacement of half of the current retail broiler meat by meat with 20-40% contamination could result in 33-93 times more human cases compared to the expected value under current situations. On the basis of the model, the interventions applied in FSCP clearly protect the public health.

Animals↗

PubMed2004

Assessment of age-related glucose oxidation rates of broiler chickens by using stable isotopes.

During their relatively short commercial lifespan of six weeks, broiler chickens undergo very pronounced age- or body weight-related changes in metabolic rate and body composition. The present study was aimed to assess the age-related changes in glucose oxidation rate of broiler chickens by using 13C-labeled glucose. The methodology for this breath test needed to be established first. Broiler chickens aged from two to six weeks were placed in open-circuit respiration cells and received a single intubation of U-13C6-glucose, followed by breath sampling for 4 hours and mass spectrometric analysis of 13C: 12C ratio in the exhaled air. Simultaneously, CO2 concentration in the respiration cell air was continuously monitored in order to calculate the cumulative percentage dose recovery (CPDR). With respect to the methodology, an oral dose of 2 mg U-13C6-glucose per kg body weight while maintaining a CO2 in the concentration of 0.4 to 0.5% was considered to be optimal. The three-parameter Gompertz curve fitted the CPDR values very well. Pronounced age-related changes in exogenous glucose oxidation rates in rapidly growing meat-type chickens were assessed. Young broiler chickens spend only a relatively low percentage of ingested glucose for immediate oxidation. In contrast, broiler chickens approaching the age of maximal absolute growth rate oxidize a greater proportion of the recently ingested glucose relative to the non-oxidative disposal pathways. This shift in the exogenous partitioning is discussed in relation to age-dependent changes in glucose turnover, lipid oxidation and deposition and metabolic heat production.

Aging↗

PubMed2004

Risk factors for the presence of Campylobacter spp. in Dutch broiler flocks.

The campylobacter status of 495 broiler flocks sampled in The Netherlands between April 1997 and December 2000 was related to farm- and flock-specific information obtained from questionnaires to identify potential risk factors for campylobacter presence. Approximately 30% of the flocks tested positive for Campylobacter spp. in at least one pooled faecal sample. Multivariable logistic regression showed significant risk increments for: ages 29-35 days (OR = 2.34) and 36-42 days (OR = 3.96) compared to 22-28 days; > or =5 broiler houses on the premises (OR = 3.02); the presence of other farm animals on the farm (OR = 1.88); the presence of animals on farms within 1 km (OR = 9.56); and summer (OR = 3.48) and fall (OR = 2.59) compared to winter. Furthermore, hatcheries differed (ORs from 5.42 to 20.2), although this variable showed strong collinearity with the variables explaining feed mill and integrated poultry operations. We also identified interaction in which an increased risk from children entering the broiler house (OR = 28.0) was diminished by the use of broiler-specific workclothes. Population attributable fractions (PAFs) suggested that animals on farms within 1 km (PAF = 0.76) and hatchery (PAF = 0.67) had the highest impacts on campylobacter presence in Dutch broiler flocks. These factors, however, lack an easy interpretation of the mechanism behind the suggested effect.

Age Factors↗

PubMed2005

Effect of dietary calcium propionate on performance, hepatic enzyme activities and aflatoxin residues in broilers fed a diet containing low levels of aflatoxin B1.

This study was undertaken to the study toxic effects of aflatoxins and reducing toxic effects of calcium propionate on performance, hepatic enzyme activities and aflatoxin residues in broilers. Two hundred and seventy 1-day-old hybrid Arbor Acor broiler chickens were fed conventional feed for 3 days. Broilers were then randomly divided into nine groups of 30 birds each. The nine dietary treatments consisted of (1) conventional feed as a negative control diet, (2) 0.25% calcium propionate, (3) 0.5% calcium propionate, (4) 50 ppb aflatoxin B1, (5) 50 ppb aflatoxin B1 plus 0.25% calcium propionate, (6) 50 ppb aflatoxin B1 plus 0.5% calcium propionate, (7) 100 ppb aflatoxin B1, (8) 100 ppb aflatoxin B1 plus 0.25% calcium propionate, (9) 100 ppb aflatoxin B1 plus 0.5% calcium propionate. Test diets were offered for 6 weeks continuously and the birds were sacrificed. Decreased body weight gain, feed consumption and feed conversion ratio were observed in aflatoxin treated groups whereas aflatoxin B1-calcium propionate supplemented diet groups increased, in comparison to the control group. Significant difference was observed after 4 weeks of feeding. Serum samples were tested for gamma glutamyl transferase (gamma-GGT), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Gamma-GGT, AST and ALT were significantly increased in aflatoxin treated groups, in comparison among the dietary treated groups. Muscle and liver tissues were analyzed for aflatoxin residues. The residual levels of aflatoxin B1 and aflatoxin M1 were significantly higher in liver than in muscle. The levels in the liver and the muscle were highest in the aflatoxin B1-supplemented groups and lower in the aflatoxin B1-calcium propionate supplemented groups. Results of this study indicate that addition of calcium propionate to diets containing aflatoxin B1 appears to be effective in reducing toxicity. Aflatoxin contamination in broiler feed may cause economic losses by lowering body weight gain. Therefore, lower levels of aflatoxin B1 in the chicken feeds should be required if all acceptable risk is to be avoided. Additionally, the risk of aflatoxins in broiler as a food appears to remain very low, although the levels of aflatoxins in human foods should be kept as low as possible to reduce the incidence of hepatic cancer.

Aflatoxin B1↗

PubMed2003

Lesions of the pericardium and their significance in the aetiology of heart failure in broiler chickens.

The present study focuses on lesions of the pericardium commonly observed in fast growing broilers. These lesions are examined in the context of electrophysiological and functional changes associated with cardiac performance and patho-physiology in broilers succumbing to acute or chronic heart failure. Typical lesions involving the pericardium in fast growing broiler chickens included: (1) excessive pericardial effusion, (2) locally extensive or focal adhesions between parietal and visceral components of the pericardium, (3) fibrous deposits on visceral pericardium, and (4) thickened pericardium. Echocardiographic evidence indicated that severe pericardial effusion and/or adhesions may have a restrictive effect on heart pump function, where both diastolic and systolic function of the heart may be affected. Electrocardiographic data showed a strong trend indicating that pericardial adhesions may be associated with ventricular arrhythmia and increased risk of sudden death in fast growing broilers. Relatively high levels of matrix metalloproteinase MMP-2 activity have been found in pericardial effusions from affected chickens, suggesting a possible involvement of this enzyme in the aetiology of pericardial lesions. The present results indicate that pericardial lesions may be associated with biochemical, morphological, electrophysiological, and functional changes occurring in the hearts of broilers succumbing to acute or chronic heart failure and ascites.

Animals↗

PubMed1998

CD4, CD8 and TCR defined T-cell subsets in thymus and spleen of 2- and 7-week old commercial broiler chickens.

To better understand immune development and function in meat-type chickens (broilers), the proportions of T-cells expressing CD4, CD8, and T-cell receptors (TCR) in the thymus and spleen were determined by three-color fluorescence and flow cytometry in 2- and 7-week old broilers raised in commercial growing conditions. Broiler thymocytes consisted of single-(CD4+CD8- and CD4-CD8+) and double-(CD4+CD8+) positive subpopulations. Within these CD4+ and/or CD8+ thymocyte populations, all types of TCR (y delta, V beta 1 alpha beta, and V beta 2 alpha beta) could be identified. In the thymus, percentages of CD4+CD8- cells increased, CD4-CD8+ cells remained unchanged, and CD4+CD8+ cells decreased between 2 and 7 weeks of age. In the spleen, in addition to single-positive lymphocytes, double-positive populations were identified, expressing either y delta or alpha beta TCR. The percentage of CD4+CD8- splenocytes decreased, and the percentages of both CD4-CD8+ and CD4+CD8+ splenocytes increased between 2 and 7 weeks of age. Age-associated shifts in TCR usage (the proportion of cells expressing a certain type of TCR) were observed in the single-positive, but not in the double-positive, T-cell populations of both thymus and spleen. This multiparameter cell population analysis in broilers demonstrates thymic and splenic T-cell subsets similar to those previously described in layers. Differences in the proportions among T-cell subsets between 2- and 7-week old broilers likely reflect a more competent immune system in the older birds.

Aging↗

PubMed2002

Factors associated with mortality in Norwegian broiler flocks.

Our aim in this longitudinal study (covering years from 1996 to 1999) was to use data regularly recorded in a production database, to identify farm- and flock-level factors associated with cumulative mortality in broiler flocks during: (a) the 1st week after housing and (b) the rest of the growout (2nd to 5th week). A total of 1664 broiler flocks kept in 132 broiler farms were included. The average weekly cumulative mortality was 1.54% (95% CI: 1.46, 1.62%) during the 1st week and 0.48% (95% CI: 0.47, 0.49%) during the rest of the growout. The final least-squares regression model of cumulative mortality during the 1st week identified the following significant factors: study year, flock size, stocking density, use of paper underlay for feeding during the 1st week, and the interaction terms between type of ventilation, drinking system and floor insulation. The final model for the 2nd to 5th week demonstrated that the factors age of the broiler house, heating system and control system for the air intake were associated with cumulative mortality, but the effects of the two latter variables were significantly modified by age of the broiler house. A significant difference in mortality between flocks delivered from various hatcheries was found in both analyses. Our results suggest that changes in several housing factors and management routines might reduce the mortality losses, but the relationship depends on the stage of production.

Animal Husbandry↗

PubMed2001

Pre-harvest surveillance of Campylobacter and Salmonella in Danish broiler flocks: a 2-year study.

In national surveillance programmes of broiler flocks carried out in Denmark during 1998 and 1999, 89,110 samples for Campylobacter representing 8911 broiler flocks were taken at 10 different abattoirs, and 44,550 samples for Salmonella were taken from the same flocks in the broiler houses at the farms. Of the swabs, 42.5% were Campylobacter positive. Most positive samples were found during July, August and September, while the lowest number of positive samples were found during January, February, March and April. Of the flocks, 5.5% were Salmonella positive, but no seasonal variation was observed. For each flock, the presence of Campylobacter and Salmonella was recorded in order to estimate the possible correlation between colonisation with the two pathogens. In conclusion, no significant effects on intensive cleaning and disinfection procedures on Campylobacter occurrence could be demonstrated, and no significant correlation between occurrence of Campylobacter and Salmonella infections in Danish broilers could be demonstrated which is in contrast to previous observations on concurrent colonisation of broilers with these two zoonotic pathogens.

Abattoirs↗

PubMed1993

Epidemiological investigation of risk factors for campylobacter colonization in Norwegian broiler flocks.

An epidemiological investigation was conducted to identify risk factors related to hygiene and husbandry practices which determine the introduction of Campylobacter spp. into broiler chicken flocks. All 176 broiler farms in an area in southeastern Norway participated in the study. Each farm was represented by one flock selected at random during a one-year period. The flocks were examined for campylobacter colonization at slaughter, and the flock managers were subsequently interviewed about hygiene and husbandry practices. Campylobacter spp. were recovered from 32 (18%) of the flocks. The proportion of colonized flocks varied geographically and seasonally with a peak in the autumn. The following variables were found to be independently associated with an increased risk of campylobacter colonization using logistic regression analysis: (i) feeding the broilers undisinfected water (odds ratio (OR) = 3.42, P = 0.045), (ii) tending other poultry prior to entering the broiler house (OR = 6.43, P = 0.007), (iii) tending pigs before entering the house (OR = 4.86, P = 0.037), (iv) geographic region (Hedmark versus Ostfold county) (OR = 2.91, P = 0.023, (v) season (autumn versus other seasons) (OR = 3.43; P = 0.008). Presence of rats on the farm was associated with an increased risk, but this factor did not reach statistical significance (OR = 3.96, P = 0.083). Preventive measures should include disinfection of drinking water and strict hygienic routines when the farm workers enter the rearing room. The results indicate that disinfection of drinking water is the preventive measure most likely to have the greatest impact on the prevalence of campylobacter among broiler chicken flocks in the study area (population attributable fraction = 0.53).

Animal Husbandry↗

PubMed2004

The effect of raw full-fat soybean and its lectin on the nutrition and pigmentation of broilers.

This study was aimed at determining the effect of raw full-fat soybean in the digestion/absorption of broilers and to evaluate the role of soybean agglutinin (SBA) in the pathogenesis of the runting and stunting syndrome of broilers. Six broiler groups were fed with six experimental diets for 42 days in which the defatted soybean meal of the basal diet was substituted with increasing raw full-fat soybean percentages ranging from 0 to 100%. The results suggested that SBA included in the raw full-fat soybean can play a role in the pathogenesis of the runting and stunting syndrome in broilers since binding and incorporation of SBA to enterocytes were associated with hyperplasia and dysplasia of the intestinal epithelium, as suggested by the progressive increases (P < 0.001) of mitosis/crypt in the duodenum and in the midintestine, as well as by intestinal villi atrophy (P < 0.001) in the duodenum and the midintestine. Indigestion and malabsorption of proteins induced progressive low weight gain (P < 0.001) up to 50% with 100% of raw full-fat soybean in the diet at 42 days. Xanthophylls in serum and skin yellowness were enhanced linearly in the broilers fed 42 days with increasing percentages of raw full-fat soybean in the diet. Increased xanthophylls absorption and decreased protein absorption can be caused by pathological changes in the epithelial intestine triggered by SBA binding and internalization.

Animals↗