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PubMed2004

Performance characteristics and economic comparison of broiler chickens fed wheat- and triticale-based diets.

The effects of triticale and wheat on broiler (mixed sexes) performance and cost of production were compared. In experiment 1, wheat- and triticale-based diets were fed to 3 strains of broilers (Ross x Ross, Hubbard x Hubbard, and Ross x Hubbard). Each of the diets was provided to 5 cages/strain (n = 10 chicks/cage; 1,273 cm2/bird). Weekly BW, gain, feed consumption, and feed conversion ratio (FCR; g of feed/g of gain) were determined. At 42 d, 4 chicks/pen were shipped to a commercial processing plant. The plucked, eviscerated carcasses were evaluated for carcass traits. Overall, the triticale-fed birds had lower final BW and average daily gain and higher FCR. Eviscerated carcass, thigh, and drum weights were lower, but pectoralis minor as a percentage of carcass weight was greater in triticale-fed birds. In experiment 2, a wheat diet and a diet in which triticale was substituted (by weight) for wheat were provided in a 3-phase feeding program. Each diet was provided to 2 identically-equipped commercial barns housing 17,034 broilers each. Individual BW of a sample of birds were recorded in each barn at 0, 19, 34, and 42 d, corresponding to the beginning and end of each dietary phase. Feed consumption and FCR were calculated for each barn. An analysis of each of the diets was calculated using a broiler chicken production cost model. Final BW, feed consumption, carcass weight at processing, flock uniformity, percentage of Grade A carcasses, and percentage of condemned carcasses were not affected by cereal source. Overall FCR (2.165, 2.036; P = 0.0052), feed cost (dollars 0.617, dollars 0.577/kg live weight; P = 0.0260), and total cost of production (dollars 1.019, dollars 0.972/kg live weight; P = 0.0183) were greater for the triticale than wheat diets, respectively. Triticale would be an economically feasible replacement for wheat in broiler diets when its price is less than or equal to 95% of the cost of wheat, less dollars 18 (Canadian). Increased knowledge of the available nutrient profile of triticale, as well as least-cost feed formulation would likely increase the value of triticale relative to wheat for broilers.

Animal Nutritional Physiological Phenomena↗

PubMed2004

Preovulatory surge patterns of luteinizing hormone, progesterone, and estradiol-17beta in broiler breeder hens fed ad libitum or restricted fed.

Spontaneous ovulations are induced by preovulatory surges of luteinizing hormone (LH) and progesterone (P4) during ovulatory cycles in birds, but estradiol-17beta (E2) levels are relatively constant. Egg production is enhanced in restricted fed (RF) in comparison with ad libitum fed (FF) broiler breeder hens, but changes in concentrations and peripheral patterns of LH, P4, and E2 during ovulatory cycles in broiler breeder hens are poorly documented. The hypothesis of this study was that high resolution patterns of peripheral LH, P4, and E2 during preovulatory surges would not be different between FF and RF broiler breeder hens. Seven FF and 6 RF broiler breeder hens were photostimulated with 16 L:8 D at 22 wk of age. At 28 wk of age, the hens were cannulated for serial blood sampling and switched to a 24L:0D photoperiod to allow preovulatory surges of LH and P4 to run freely. Three days after cannulation, hens were serially bled every 12 min for 36 h. The FF hens were heavier than the RF hens (5.60 +/- 0.35 vs. 3.60 +/- 0.28 kg, respectively; P < 0.01). During the 10 d before cannulation, total egg production of the FF and RF hens (8.3 +/- 1.4 and 6.8 +/- 1.3 eggs, respectively; P = 0.08) and normal egg production (5.6 +/- 1.8 and 6.5 +/- 1.8 eggs, respectively; P = 0.37) were not different. The FF hens, however, had more abnormal eggs than the RF hens (2.7 +/- 1.7 and 0.3 +/- 0.8 eggs, respectively; P < 0.01). None of the hormonal measurements was different between the FF and RF hens (P > 0.05). The concentrations of hormones for the FF and RF hens, respectively, were as follows: baseline LH (2.79 +/- 0.45 vs. 2.94 +/- 0.60 ng/mL) and P4 (1.68 +/- 0.56 vs. 1.41 +/- 0.43 ng/mL), overall mean LH (3.18 +/- 0.45 vs. 3.10 +/- 0.46 ng/mL) and P4 (2.32 +/- 0.55 vs. 2.09 +/- 0.91 ng/ mL), preovulatory surge amplitude of LH (5.43 +/- 1.27 vs. 3.88 +/- 1.24 ng/mL) and P4 (6.08 +/- 2.09 vs. 6.71 +/- 3.91 ng/ mL), preovulatory surge duration of LH (7.52 +/- 1.80 vs. 5.74 +/- 3.18 h) and P4 (7.52 +/- 1.42 vs. 8.20 +/- 1.24 h), and overall mean E2 (0.25 +/- 0.05 vs. 0.23 +/- 0.05 ng/mL). In conclusion, there were no differences in total egg production or normal egg production between FF and RF broiler breeder hens, but the FF hens laid more abnormal eggs. Also, there were no differences in the concentrations or peripheral patterns of LH, P4, and E2 during preovulatory surges between the FF and RF broiler breeder hens.

Animals↗

PubMed2004

On-farm euthanasia of broiler chickens: effects of different gas mixtures on behavior and brain activity.

The purpose of this study was to investigate the suitability of gas mixtures for euthanasia of groups of broilers in their housing by increasing the percentage of CO2. The suitability was assessed by the level of discomfort before loss of consciousness, and the killing rate. The gas mixtures injected into the housing were 1) 100% CO2, 2) 50% N2 + 50% CO2, and 3) 30% O2 + 40% CO2 + 30% N2, followed by 100% CO2. At 2 and 6 wk of age, groups of 20 broiler chickens per trial were exposed to increasing CO2 percentages due to the injection of these gas mixtures. Behavior and killing rate were examined. At the same time, 2 broilers per trial equipped with brain electrodes were observed for behavior and brain activity. Ten percent of the 2-wk-old broilers survived the increasing CO2 percentage due to the injection of 30% O2 + 40% CO2 + 30% N2 mixture, therefore this mixture was excluded for further testing at 6 wk of age. At 6 wk of age, 30% of the broilers survived in the 50% N2 + 50% CO2 group. The highest level of CO2 in the breathing air (42%) was reached by the injection of the 100% CO2 mixture, vs. 25% for the other 2 mixtures. In all 3 gas mixtures, head shaking, gasping, and convulsions were observed before loss of posture. Loss of posture and suppression of electrical activity of the brain (n = 7) occurred almost simultaneously. The results of this experiment indicate that euthanasia of groups of 2- and 6-wk-old broilers by gradually increasing the percentage of CO2 in the breathing air up to 40% is possible.

Animals↗

PubMed2005

Feeding high levels of lupine seeds to broiler chickens: plasma micronutrient status in the context of digesta viscosity and morphometric and ultrastructural changes in the gastrointestinal tract.

This work examines the effects of lupine-based diets on the status of the host's riboflavin and zinc. Test diets contained 35% soybean meal (control) or raw (40%) or dehulled (35%) lupine seed meal and were isocaloric (13.4 MJ of AME/kg) and isonitrogenous (23% crude protein). Each diet was offered ad libitum to a group of 16 male commercial broiler chicks for 21 d, starting at 1 d of age. Broilers fed lupine diets had lower feed intakes and growth rates. All sections of the intestinal tract were significantly enlarged (P < 0.01) in all groups fed lupine-based diets in comparison with broilers fed the soybean meal diet, but there were no differences in the morphologies of the mucosa, submucosa, muscularis, or serosa. Increased size of the duodenum, jejunum, and ileum was predominantly attributed to the increase in length rather than intestinal tissue mass. Hence, the enlargement of the intestinal tract was consistent with physiological hyperplasia and not pathological remodeling and hypertrophy. Overall, broilers fed lupine-based diets had more viscous digesta than those fed the soybean meal diet, but the differences were statistically not significant. Blood plasma Zn concentration did not differ between broilers fed lupine-based diets and those fed soybean-meal-based diets, and all broilers fed lupine-based diets had significantly higher (P < 0.001) riboflavin concentrations. In this context, it is apparent that the bioavailability of these micronutrients from lupine diets is not compromised. Intestinal tissue hyperplasia may be interpreted as physiological adaptation to increase absorptive capacity and thus maximize absorption of essential nutrients in the face of antinutritional factors in the diet.

Animal Feed↗

PubMed2005

Effect of sand and wood-shavings bedding on the behavior of broiler chickens.

The purpose of this study was to determine the effect of 2 different bedding types, sand and wood shavings, on the behavior of broiler chickens. In experiment 1, 6 pens were divided down the center and bedded half with sand and half with wood shavings. Male broilers (10/pen) were observed by scan sampling at 5- or 12-min intervals throughout the 6-wk growth period during the morning (between 0800 to 0900 h), afternoon (1200 to 1500 h), and night (2300 to 0600 h). There was a significant behavior x substrate x week interaction during the day (P < 0.0001) and at night (P < 0.0002). Drinking, dustbathing, preening, and sitting increased in frequency on the sand side but decreased on the wood shavings side during the day, as did resting at night. In general, broilers performed a greater proportion of their total behavioral time budget on the sand (P < 0.0001) as they aged. Broilers used the divider between the 2 bedding types to perch; perching behavior peaked during wk 4. In experiment 2, male broilers were housed in 8 pens (50 birds/pen) bedded only in sand or wood shavings. Bedding type had no effect on behavioral time budgets (P = 0.8946), although there were age-related changes in behavior on both bedding types. These results indicate that when given a choice, broilers increasingly performed many of their behaviors on sand, but if only one bedding type was provided they performed those behaviors with similar frequency on sand or wood shavings.

Aging↗

PubMed2006

Comparison of amino acid digestibility in broiler chickens, turkeys, and Pekin ducks.

The objective of this study was to compare prececal amino acid (AA) digestibilities in broilers, turkeys, and Pekin ducks that were 3 wk old. Five diets were used: a basal diet and diets that contained either soybean meal (SBM) or rapeseed meal (RSM) at the expense of starch each at either 150 or 300 g/kg. The differences in dietary CP and AA concentrations resulted only from the inclusion of SBM or RSM. Titanium dioxide was used as an indigestible marker. Each diet was allocated to 6 pens of 12 birds from each species and provided ad libitum for 1 wk starting at 14 d of age. Digesta were sampled on a pen basis from the distal two-thirds of the section between Meckel's diverticulum and 2 cm anterior to the ileocecocolonic junction. Ingested and digested amounts of AA were determined for each pen. Digestibilities for the 2 meals were then determined by a multiple linear regression analysis, which makes a correction for basal endogenous AA losses unnecessary. Digestibilities for essential AA from the meals varied between 92% (Met, RSM, broilers) and 62% (Val, RSM, ducks). Digestibilities were not significantly different between SBM and RSM for broilers and turkeys, but the average digestibility across all AA was slightly higher for SBM and lower for RSM in turkeys than in broilers. Digestibilities were lower in ducks than in the 2 other species, and significant differences between SBM and RSM were detected for some AA in ducks. Amino acid digestibility ranking was very similar between broilers and turkeys but different for the 2 meals. It was concluded that differences among species cannot be explained by differences in basal endogenous AA losses among species. Amino acid digestibilities determined with broilers should not be used in formulating feed for ducks.

Amino Acids↗

PubMed2006

Pulmonary hypertension triggered by lipopolysaccharide in ascites-susceptible and -resistant broilers is not amplified by aminoguanidine, a specific inhibitor of inducible nitric oxide synthase.

Nitric oxide (NO) is a potent pulmonary vasodilator that modulates the pulmonary vasoconstriction and pulmonary hypertension (PH) triggered by bacterial lipopolysaccharide (LPS) in broilers. The amplitude and duration of the LPS-induced PH are markedly enhanced following pretreatment with N(omega)-nitro-L-arginine methyl ester (L-NAME), which inhibits NO synthesis by both the constitutive (endothelial) and inducible (inflammatory) forms of nitric oxide synthase (eNOS and iNOS, respectively). In the present study L-NAME and the selective iNOS inhibitor aminoguanidine (AG) were administered to differentiate between iNOS and eNOS as the primary source of NO that attenuates the pulmonary vascular response to LPS. Clinically healthy male progeny from ascites-susceptible and ascites-resistant lines were anesthetized, and their pulmonary artery was cannulated. The initial pulmonary arterial pressure (PAP) was recorded, then the broilers either remained untreated (control group) or were injected i.v. with AG. Ten minutes later all birds received an i.v. injection of LPS, followed 40 min later by an i.v. injection of L-NAME. When compared with untreated controls, AG neither increased the baseline PAP nor did it increase or prolong the PH response to LPS. The ascites-susceptible broilers maintained a higher PAP than the ascites-resistant broilers throughout the experiment, and the ascites-resistant broilers exhibited greater relative increases in PAP in response to LPS than did the ascites-susceptible broilers. Within 40 min after the LPS injection, PAP subsided to a level that did not differ from the respective preinjection value for each line. Injecting L-NAME reversed the decline in PAP, and within 5 min PAP returned to hypertensive levels approaching the maximum peak PH response to LPS. The absence of any impact of AG coupled with the profound response to L-NAME indicates that NO synthesized by eNOS rather than iNOS likely modulated the acute (within 1 h) PH elicited by LPS. Evidently eNOS is activated by the increased shear stress exerted on the endothelium during the PH response to LPS, whereas LPS-mediated up-regulation of iNOS expression may take longer than 1 h before biologically effective quantities of NO are produced.

Animals↗

PubMed2007

Recovery of Campylobacter from commercial broiler hatchery trayliners.

Previous research has identified Campylobacter as one of the leading causes of foodborne illness. Poultry and poultry products have been identified as a major source of Campylobacter in human infections. Although many risk factors that contribute to Campylobacter levels have been identified, precise identification of the most effective sites for intervention has not been established. Epidemiological studies have identified that Campylobacter in the broiler breeder's reproductive tract, fertile eggs, and 2- to 3-wk-old broilers has the potential to contaminate day-of-hatch chicks. Numerous studies have shown that day-of-hatch broilers are Campylobacter-negative using conventional culture methods. The purpose of the present study was to demonstrate the prevalence of Campylobacter found in day-of-hatch broilers using a peptone water preenrichment followed by conventional Campylobacter culture methods. Using conventional tray liner (hatcheries) culture methods, the isolation distribution of Campylobacter from 8 commercial broiler hatcheries (n = 2,000) was evaluated. A total of 15 tray liners were positive from 3 different hatcheries. Of the 2,000 chick paper pad tray liners sampled, 0.75% were positive for Campylobacter. These data support previous findings indicating the potential for Campylobacter to be spread by vertical transmission. This is the first time that Campylobacter has been recovered from tray liners collected at commercial broiler hatcheries.

Animals↗

PubMed2006

Effects of feeding deoxynivalenol contaminated wheat on growth performance, organ weights and histological parameters of the intestine of broiler chickens.

A feeding trial was conducted to evaluate the effects of moderate dietary concentrations of deoxynivalenol (DON) during a 21-day feeding experiment on the performance of broilers. Fifteen 1-day-old broiler chicks were randomly divided into two groups. The control group was fed non-contaminated diet. Another group of broilers was fed a diet naturally contaminated with 5 mg DON/kg diet. Deoxynivalenol had no effect (p > 0.05) on feed consumption, feed conversion, body-weight gain, live body weight or mortality. The absolute and relative weight of the organs (gizzard, pancreas, heart, spleen, colon and caecum) were not altered by the dietary inclusion of DON contaminated grain. However, both the absolute and relative weight of small intestine was decreased (p < 0.01) in DON fed broilers compared to the controls. No gross lesions were detected in any of the organs of birds fed contaminated wheat during the feeding trial. The microscopic examination revealed that, the height and the width of villi in duodenum decreased (p < 0.05) in birds fed DON contaminated wheat compared to controls. On the other hand the height and the width of jejunum villi were not affected (p > 0.05). This study indicates that feeding DON for 21 days to broiler chickens at a concentration of up to 5 mg/kg of diet influenced the weight of the small intestine as well as intestinal histology, especially the duodenum, as evidenced by shorter and thinner villi. In conclusion, diets with DON contamination below levels that induce negative impact on health and performance could affect small intestinal morphology in broilers.

Animal Feed↗

PubMed2001

Evidence that certain clones of Campylobacter jejuni persist during successive broiler flock rotations.

Through the national surveillance program for Campylobacter spp., nine broiler chicken farms that were infected with Campylobacter jejuni in at least five rotations in 1998 were identified. One additional farm, located at the island of Bornholm where divided slaughter is used extensively, was also selected. Twelve broiler houses located on 10 farms were included in the study. The C. jejuni isolates collected from the selected houses during the surveillance were typed using fla typing and macrorestriction profiling (MRP), and a subset of the isolates, representing each of the identified clones, was serotyped according to the Penner scheme. Pulsed-field gel electrophoresis typing using SmaI and KpnI revealed that the majority of houses (11 of 12) carried identical isolates in two or more broiler flocks. Such persistent clones were found in 63% of all flocks (47 of 75). The majority of persistent clones (7 of 13) had fla type 1/1, but MRPs distinguished between isolates from different houses, and fla type 1/1 clones belonged to different serotypes. Seven houses carried persistent clones that covered an interval of at least four broiler flock rotations, or at least one half year. The dominant fla type (1/1) was represented by 44% of isolates, or by at least one isolate from 31 of 62 broiler flocks. This significantly exceeded the prevalence of fla type 1/1 C. jejuni isolates that we have estimated from other studies and suggests that isolates carrying this fla type are overrepresented in flocks with recurrent Campylobacter problems. The MRPs of clones belonging to fla type 1/1 serotype O:2 isolated from persistently infected flocks shared a high percentage of bands compared to the remaining isolates, indicating that some clones that have the ability to cause persistent infections in broiler farms are highly related to each other.

Animal Husbandry↗

PubMed2005

Quantifying transmission of Campylobacter spp. among broilers.

Campylobacter species are frequently identified as a cause of human gastroenteritis, often from eating or mishandling contaminated poultry products. Quantitative knowledge of transmission of Campylobacter in broiler flocks is necessary, as this may help to determine the moment of introduction of Campylobacter in broiler flocks more precisely. The aim of this study was to determine the transmission rate parameter in broiler flocks. Four experiments were performed, each with four Campylobacter-inoculated chicks housed with 396 contact chicks per group. Colonization was monitored by regularly testing fecal samples for Campylobacter. A mathematical model was used to quantify the transmission rate, which was determined to be 1.04 new cases per colonized chick per day. This would imply that, for example, in a flock of 20,000 broilers, the prevalence of Campylobacter would increase from 5% to 95% within 6 days after Campylobacter introduction. The model and the estimated transmission rate parameter can be used to develop a suitable sampling scheme to determine transmission in commercial broiler flocks, to estimate whether control measures can reduce the transmission rate, or to estimate when Campylobacter was introduced into a colonized broiler flock on the basis of the time course of transmission in the flock.

Animals↗

PubMed2005

Genomic diversity of Campylobacter coli and Campylobacter jejuni isolates recovered from free-range broiler farms and comparison with isolates of various origins.

In many industrialized countries, the incidence of campylobacteriosis exceeds that of salmonellosis. Campylobacter bacteria are transmitted to humans mainly in food, especially poultry meat products. Total prevention of Campylobacter colonization in broiler flocks is the best way to reduce (or eliminate) the contamination of poultry products. The aim of this study was to establish the sources and routes of contamination of broilers at the farm level. Molecular typing methods (DNA macrorestriction pulsed-field gel electrophoresis and analysis of gene polymorphism by PCR-restriction fragment length polymorphism) were used to characterize isolates collected from seven broiler farms. The relative genomic diversity of Campylobacter coli and Campylobacter jejuni was determined. Analysis of the similarity among 116 defined genotypes was used to determine clusters within the two species. Furthermore, evidence of recombination suggested that there were genomic rearrangements within the Campylobacter populations. Recovery of related clusters from different broiler farms showed that some Campylobacter strains might be specifically adapted to poultry. Analysis of the Campylobacter cluster distribution on three broiler farms showed that soil in the area around the poultry house was a potential source of Campylobacter contamination. The broilers were infected by Campylobacter spp. between days 15 and 36 during rearing, and the type of contamination changed during the rearing period. A study of the effect of sanitary barriers showed that the chickens stayed Campylobacter spp. free until they had access to the open area. They were then rapidly colonized by the Campylobacter strains isolated from the soil.

Animal Husbandry↗

PubMed1992

Subclinical infectious bursal disease in an integrated broiler production operation.

A field study was designed to determine the prevalence of subclinical infectious bursal disease (IBD) in broiler chickens from a commercial poultry company. Bursae of Fabricius (BF) from two vaccinated and three nonvaccinated broiler flocks were evaluated histologically, and antibody profiles of these broiler and matched parent breeder flocks were established. Lesions of IBD, including lymphoid necrosis, stromal edema, and infiltrates of heterophils and macrophages, were first detected in BF at 24 days of age in both vaccinated and nonvaccinated chickens. At 41 days, all BF had lesions characteristic of IBD, including severe lymphoid depletion, proliferation of epithelial cells, and mild fibroplasia. Although mean maternal antibody levels (measured by enzyme-linked immunosorbent assay) in broilers were apparently protective through day 12, IBD antibodies decreased to nonprotective levels (below 1,000) by day 16 or 20. Titers began to increase by day 28 or 32 because of field exposure. Sentinel birds, placed with broiler flocks, also developed IBD antibody titers. Broiler breeders had low and nonuniform antibody titers. Prevalence of field IBD exposure was high, and existing vaccination programs were not effective.

Animals↗

PubMed1990

Photoperiodic requirements for LH release in juvenile broiler and egg-laying strains of domestic chickens fed ad libitum or restricted diets.

Photoperiodic response curves for LH release were obtained for juvenile female domestic chickens at 8 weeks of age by measuring changes in plasma LH concentrations after increasing the daily photoperiod from 8 to 10.5, 12.75, 15.25, 17.75 or 20 h. The birds were bred either for meat production (broiler) or commercial egg-laying and were fed ad libitum or a restricted diet, similar to that used under commercial conditions. Ovarian and oviduct growth was stimulated by 2 weeks after transfer to 20 h light/day in the dwarf broiler strain, irrespective of the dietary treatment, but not in birds of the egg-laying strain. Baseline concentrations of plasma LH were higher in the egg-laying than in the dwarf broiler strain birds. A significant effect of dietary treatment was observed on the changes in concentration of plasma LH in the nonphotostimulated dwarf broiler, but not in the egg-laying bird. There was no significant interaction between dietary treatment and photoinduced LH release in birds of either strain. The shortest photoperiod needed to stimulate LH release (critical daylength) was less than 10.5 h in the dwarf broilers and between 10.5 and 12.75 h in the egg-laying birds. The shortest photoperiod needed to stimulate the maximum release of LH (saturation daylength) was between 10.5 and 12.75 h in the dwarf broiler strain. The saturation daylength in birds of the egg-laying strain was longer, being between 12.75 and 15.25 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Differential sensitivity of ovarian follicles to gonadotrophin stimulation in broiler and layer lines of domestic fowl.

Differences in the reproductive potential of female broiler parent and layer fowl are related to differences in the recruitment of follicles to the preovulatory hierarchy. Broiler and laying hens were fed ad libitum or a restricted diet during rearing and ad libitum after sexual maturity. The sensitivity of thecal tissue, from ovarian follicles of different sizes, from layer and broiler fowl to stimulation by pregnant mares' serum gonadotrophin (PMSG) was determined to test the hypothesis that differences in egg production are associated with changes in the sensitivity of ovarian follicles to stimulation by gonadotrophin. The activity of ornithine decarboxylase 0.5-4 h after injection of 200 iu PMSG kg-1 body mass was assessed in thecal tissue from small white follicles 2-3 and 5-6 mm in diameter and in the smallest preovulatory yellow follicle. Basal activity was similar in layers and broiler breeders. PMSG-stimulated ornithine decarboxylase activity in follicles of 5-6 mm diameter was greater in broiler breeders than in layers. There was no difference between the lines in PMSG-stimulated ornithine decarboxylase activity in follicles of 2-3 mm diameter or in small yellow follicles. It was concluded that the low egg production and high prevalence of eggs with defective shells in broiler parents compared with layers may be related to the increased sensitivity of follicles to endogenous gonadotrophins at the critical stage of recruitment to the preovulatory hierarchy.

Animal Nutritional Physiological Phenomena↗

PubMed2005

Characterization of Enterococcus hirae outbreaks in broiler flocks demonstrating increased mortality because of septicemia and endocarditis and/or altered production parameters.

In Denmark, increased problems associated with streptococci and enterococci have been observed in broilers and broiler parent flocks, resulting in increased mortalities, uneven flocks, and subsequent downgrading and increased condemnations. Postmortem lesions associated with recent outbreaks due to Enterococcus hirae have been accompanied or dominated by septicemia and endocarditis. As a result of infection at an early age and relatively low mortality rates, outbreaks are not always clearly defined and may go unnoticed or may be attributed to poor chick quality. For the same reasons, the pathogenesis and epidemiology of observed outbreaks has only remained speculative. Four separate outbreaks associated with E. hirae infections in broiler flocks occurring between 1998 and 2002 have been investigated. Two of the outbreaks indicated evidence of two separate clones, with 89% and 79% of isolates involved in the individual outbreaks belonging to a single pulsed-field gel electrophoresis (PFGE) profile, respectively. Another outbreak (outbreak 4) demonstrated clear clonality, with all isolates demonstrating affinity to one of two PFGE profiles that differed by only two bands. However, all three outbreaks demonstrated a different clone. The remaining outbreak was nondonal, with isolates distributed between six separate PFGE profiles. One of the outbreaks (outbreak 4) was descended from a parent broiler flock previously associated with an outbreak of Streptococcus gallinaceus; the flock also exhibited septicemia and endocarditis. Initial indications suggested the possibility of vertical transmission of S. gallinaceus to the current broiler flock, causing infection. By extended phenotypic characterization and subsequent genetic characterization, including 16S rRNA sequencing, all strains from the four outbreaks were confirmed as E. hirae. This investigation highlights the problems associated with characterizing enterococci infections in broiler flocks.

Animal Husbandry↗

PubMed2006

A comparison survey of organic and conventional broiler chickens for infectious agents affecting health and food safety.

The purpose of the present cross-sectional study was to evaluate the health status of organic broiler chickens and the contamination rate with Salmonella and Campylobacter in organic broiler production in Belgium. The broilers were screened for antibodies against routinely monitored poultry diseases at 1 day old and at slaughter. Fecal examination for the presence of worm eggs was done at slaughter. Bacteriological examination for the detection of Salmonella and Campylobacter was performed at day 1, week 2, week 4, week 7, week 10, and slaughter. Conventional broilers of the same poultry integration and reared in the same geographic area were also screened and served as reference. Serologic data indicated lower antibody titers against infectious bronchitis and Newcastle disease in organic flocks. No significant differences could be found in prevalence of Salmonella between organic and conventional broilers at slaughter. In contrast, Campylobacter infections at slaughter were significantly higher in organic flocks. Organic flocks most probably become infected with Campylobacter between week 7 and week 10. Worm eggs were found in neither the organic flocks nor the conventional flocks. In conclusion, there are indications that the respiratory health status is better in organic broilers but that organic flocks are more often infected with Campylobacter than are conventional flocks.

Aging↗

PubMedDate not supplied

Rapid methods to determine potentially mineralizable nitrogen in broiler litter.

Although broiler (chicken, Gallus gallus domesticus) litter has long been used as a fertilizer, estimating the rate required to supply a desired amount of plant-available N is still hampered by the lack of rapid methods to estimate potentially mineralizable nitrogen (PMN). Previous research has suggested that near infrared reflectance spectroscopy (NIRS) and certain poultry litter characteristics, such as water-soluble organic nitrogen (WSON), may be useful for estimating PMN. The objectives of this study were to evaluate NIRS and WSON as tools to estimate PMN in broiler litter. Sixty sieved (2 mm) and freeze-dried broiler litter samples were mixed with Cowarts sandy loam soil (fine-loamy, kaolinitic, thermic Typic Kanhapludult) and incubated at 25 degrees C for 112 d. Cumulative net N mineralized with time was fitted to a single-pool exponential model to determine PMN for each broiler litter sample. The PMN values obtained were regressed against NIRS (780 to 2500 nm) and WSON measurements. We found strong relationships between measured- and NIRS-predicted PMN (R2 = 0.82), and between measured PMN and WSON (R2 = 0.87). These results demonstrate the feasibility of using either of these two methods to estimate PMN in broiler litter. Future work should further test both methods for their ability to estimate mineralizable N in whole, moist broiler litter under field conditions.

Agriculture↗