Gene expression profile of IGF1 and MSTN mRNA and their correlation with carcass traits in different breeds of geese at 70 d of age

1. The expression of insulin-like growth factor-1 (IGF1) and myostatin (MSTN) mRNA in breast and leg muscle was quantified in 70-d-old Taihu and Wanxi geese by using a Multiplex Competitive Fluorescent–PCR method and the correlations between mRNA levels and carcass traits were analysed.

2. IGF1 mRNA expression in breast muscle in Taihu geese was significantly higher than that in Wanxi geese and the MSTN mRNA level in leg muscle in Taihu geese was significantly higher than that in Wanxi geese.

3. There was no significant difference in breast muscle MSTN or leg muscle IGF1 mRNA expression between the two breeds.

4. Within the same breed, the IGF1 mRNA expression in leg muscle of male geese was significantly higher than that in female geese, and MSTN mRNA expression in leg muscle was significantly higher than that in breast muscle.

5. There was no difference in the IGF1 mRNA expression between tissues.

6. There was a positive correlation between IGF1 mRNA and MSTN mRNA and a negative correlation between IGF1 mRNA expression of breast muscle and leg muscle ratio.

7. In Wanxi geese, MSTN mRNA expression in leg muscle was negatively associated with body weight and leg muscle weight.     

Production traits of artificially and naturally hatched geese in intensive and free-range systems – II: slaughter,carcass and meat quality traits

1. This study investigates the slaughter, carcass and meat quality traits of artificially and naturally hatched geese in intensive and free-range production systems.

2. The study was conducted with 114 naturally hatched and 102 artificially hatched geese. From each replicate of the intensive and free-range systems, one female and one male goose were slaughtered at the ages of 14, 16 and 18 weeks (a total of 32 geese per slaughter week).

3. Artificially hatched geese had higher slaughter weights (5280 vs. 4404 g), carcass weights (3520 vs. 2863), dressing percentages (66.6–65.2% vs. 65.0–63.6%) and carcass part, feather and edible inner organ weights. The ratio of both edible inner organs and abdominal fat was higher in naturally hatched geese. Breast meat L*, a* and pH values and thigh meat dry matter values were higher in artificially hatched geese, whereas thigh meat b* and pH values were higher in naturally hatched geese.

4. Intensively reared geese had higher slaughter weights (4900 vs. 4783 g), carcass weights (3253 vs. 3130 g) and abdominal fat weights (280 vs. 250 g), as well as higher dressing percentages (66.3–64.9% vs. 65.3–63.9%). Breast meat b* and thigh meat L* values were higher in the intensive system, while breast and thigh pH values, dripping loss and cooking loss were higher in the free-range system. Water-holding capacity was higher in the intensive system.

5. In conclusion, artificially hatched, intensively reared geese had the highest slaughter weights; however, both artificially and naturally hatched geese raised in a free-range system reached acceptable slaughter weights and can thus be recommended for use with this type of production system.     

Production traits of artificially and naturally hatched geese in intensive and free-range systems: I. Growth traits

1. This study investigated the effect of incubation type and production system on geese growth traits.

2. A total of 216 geese were either naturally (114) or artificially (102) hatched and reared in intensive or free-range production systems (4 replicates each) until 18 weeks of age.

3. Weights of naturally hatched goslings (NHG) were significantly higher than artificially hatched goslings (AHG) at 2 weeks (644 vs. 536 g); however, weights of AHG were significantly higher than NHG at both 6 weeks (3245 vs. 3010 g) and 18 weeks (5212 vs. 4353 g).

4. AHG had better feed conversion ratios (FCRs) than NHG (6.21 vs. 6.46 at 18 weeks). Feed consumption of naturally hatched geese was found higher in first 4 weeks when compared to artificially hatched geese and artificially hatched geese consumed more feed than naturally hatched geese after 8 weeks.

5. Production system had insignificant effects on feed consumption, FCRs, viability and mutilation rates.

6. Slipped wings were more frequent in NHG than AHG (8.32% vs. 1.68% at 6 weeks; 23.84% vs. 5.12% between 7 and 18 weeks) and in free-range production when compared to intensive production (17.88% vs. 11.08% over the course of the production period).

7. The study results indicate that both artificially and NHG can be reared in free-range production systems without any loss in performance and in deference to animal welfare.     

An analysis of sexual size dimorphism in goose

1. Sexual size dimorphism (SSD) is a common phenomenon in animals. Rensch’s rule states that larger species generally exhibit a higher male to female body size ratio than smaller ones.

2. Domesticated animals offer excellent opportunities for testing predictions of the functional explanations of Rensch’s rule and this was tested in a meta-analysis of SSD in 38 breeds of domestic geese compared among themselves and with their wild relatives (subfamily Anserinae, 35 species).

3. Domestic geese and wild Anser species taken together supported Rench’s rule but the wild species did not.

4. The non-targeted sex selection hypothesis seems to provide the best intuitive explanation for the lack of SSD in geese.     

Correlations between body measurements and tissue composition of oat-fattened White Kołuda geese at 17 weeks of age

1.?The aim of the present study was to evaluate the yield and tissue composition of carcases from White Ko?uda® ganders (males) and geese (females), and to determine the relationships between body measurements and carcase tissue composition.

2.?The experiment was carried out on 200 geese (100 males and 100 females) reared to 14 weeks of age and then fed with oats for the next 3 weeks. Live body weight and body dimensions, slaughter yield, weight and percentage of muscles and skin with fat in carcase were measured and correlation coefficients were calculated between body measurements and slaughter values and carcase tissue composition.

3.?White Ko?uda® geese reared to 17 weeks of age were characterised by high body weight (6705 g) and good muscle yield (29·9%). Males had greater body weight, musculature and fatness than females. Sternum length and breast circumference, width and depth were good indicators of carcase muscle weight in 17-week-old geese.

4.?Negative coefficients of correlation between sternum length and weight of skin with subcutaneous fat indicate that increased selection pressure in pedigree flocks of geese on sternum length should be paralleled by reduced carcase fatness in these birds.     

Effects of phytoestrogens on testosterone secretion by Leydig cells from Biłgoraj ganders (Anser anser)

1. The aim of this study was to examine ganders at different stages of the reproductive season and the effect of: (1) diets with high phytoestrogen content and (2) in vitro phytoestrogen treatment on testosterone secretion by isolated Leydig cells.

2. Thirty-six male Bi?goraj geese were fed control diets with low phytoestrogen content (containing grass meal) and diets with high phytoestrogens (containing alfalfa meal and soy).

3. Testes were obtained from both groups of ganders at three different times of the breeding season: peak of reproductive activity (March), second half of reproductive activity (May) and beginning of photorefractoriness (July).

4. Isolated Leydig cells were incubated with LH as well as genistein, daidzein, equol and coumestrol and the concentration of testosterone in the medium was determined by radioimmunoassay.

5. The mean weight of testes from ganders in May and July decreased relative to their weights in March, but no significant differences among experimental groups were noted.

6. No differences were observed in basal and LH-stimulated testosterone secretion by Leydig cells of ganders fed the control diets and the diets with higher phytoestrogen content. In July, LH did not stimulate testosterone secretion in either group. In vitro treatment with genistein, daidzein and equol (5 and 50?µM) inhibited basal and LH-stimulated testosterone production by Leydig cells from both groups. Coumestrol (5 and 50?µM) inhibited basal testosterone secretion only in March in the control group.

7. Dietary exposure to phytoestrogens had a slight effect on in vitro testicular secretion in ganders. In vitro treatment with phytoestrogen inhibited testosterone production by Leydig cells. Genistein showed the strongest effect and coumestrol had the weakest influence on testicular secretion.     

The effect of glycerol on mRNA expression of growth hormone,insulin-like growth factor,and mitochondrial breast muscle genes of Japanese quail

1. A study was carried out to evaluate the expression of growth hormone (GH), insulin-like growth factor I (IGF-I), mitochondrial adenine nucleotide translocase (ANT), cytochrome oxidase III (COX III) and avian uncoupling protein (avUCP) genes in 14-d-old Japanese quail that were fed different levels of glycerol (0%, 4%, and 12% dietary glycerol) which replaced maize as an energy source.

2. Total RNA was extracted from the breast muscle, and cDNA was amplified using real-time PCR with primers specific to the examined genes.

3. Quail fed the diet with 12% glycerol supplementation presented higher growth hormone (GH) mRNA expression than did those fed 0% glycerol. Supplementation with 12% glycerol negatively influenced IGF-I mRNA expression and reduced ANT mRNA expression in comparison with the treatment with no glycerol. COX III mRNA expression in the pectoralis superficialis muscle was decreased by 26% in quail fed 12% glycerol compared with those fed 0 and 4% glycerol.

4. There was no difference in UCP mRNA expression between quail fed 0 and 4% glycerol; however, UCP expression was reduced (73%) in birds fed the 12% glycerol diet compared with the level in those fed the 4% glycerol diet.

5. The inclusion of 4% glycerol in the diet produced results similar to those of the diet with no glycerol. Based on quail performance and the expression of the GH, IGF-I, ANT, COX III and UCP genes, 4% glycerol can be used in quail feeding without any harmful effects.     

Changes in plasma gonadotrophins, testosterone, prolactin, thyroxine and triiodothyronine concentrations in male Japanese quail (Coturnix coturnix japonica) of a heavy body weight line during photo-induced testicular growth and regression

1. Simultaneous changes of cloacal gland area (CGA) and plasma luteinising hormone (LH), follicle stimulating hormone (FSH), testosterone (T), prolactin (PRL), thyroxine (T₄) and triiodothyronine (T₃) during photo-induced testicular growth and regression were measured in commercially bred Japanese quail from a heavy body weight line.

2. Somatically mature male Japanese quail were transferred from short days (light:dark 8L:16D) at 10°C, to long days (16L:8D) at 20°C; and sexually mature male Japanese quail were transferred from long to short days. All variables were measured at transfer and every 5?d thereafter for 35?d.

3. Transfer from short to long days caused significant increases in LH, FSH, T and testis weight (TW) after 5?d, and in CGA after 10?d. T₃ decreased after 5?d, whereas T₄ increased significantly after 25 long days and PRL did not undergo any consistent change. The testicular growth rate was k?=?0·1146.

4. Transferring quail from long to short days caused significant decreases in LH and FSH after 5?d, and decreases in T, TW and CGA after 10?d. T₄ decreased after 5?d whilst T₃ increased significantly by day 15. PRL decreased significantly after 10?d then rose before declining again. The testicular regression rate was k?=?0·0582.

5. The rates of photo-induced testicular development and regression in a strain of large Japanese quail did not differ from rates reported for other strains of quail. CGA was a better indicator of TW than plasma T concentrations during growth and regression. The role of PRL in photo-induced reproductive cycles in male Japanese quail remains to be determined.

6. The photoperiod-induced changes in gonad size and hormone concentrations, together provide valuable information that can be used in future studies of the endocrinology and neuroendocrinology of photoperiodism in birds.     

The effect of heat stress on GHR,IGF-I,ANT, UCP and COXIII mRNA expression in the liver and muscle of high and low feed efficiency female quail

1. A study was conducted to test the hypothesis that feed efficiency (FE) correlated with the expression of genes from the somatotropic axis and mitochondrial genes involved in energy production, and that the environment to which the birds are exposed influenced the expression of such genes.

2. Quails were divided into High-FE and low-FE groups and maintained in a comfortable or heat stress (HS) (38°C for 24 h) environment to evaluate changes in insulin-like growth factor I (IGF-I), growth hormone receptor (GHR), adenine nucleotide translocator (ANT), uncoupling protein (UCP) and cytochrome oxidase subunit III (COX III) messenger ribonucleic acid (mRNA) expression in liver and muscle tissues.

3. High-FE quails (0.28 g/g) presented a higher final body weight, greater weight gain and a better feed conversion ratio than low-FE birds (0.18 g/g). High-FE birds showed greater IGF-I mRNA expression in the liver and muscle and greater GHR mRNA expression in the muscle.

4. Environmental effects only affected GHR expression in the liver, with quails under comfortable conditions exhibiting greater GHR expression than quails subjected to HS.

5. There was a significant interaction between FE and environmental temperature on ANT mRNA expression in the liver. The greatest ANT mRNA expression was observed for high FE-birds that remained under comfortable conditions.

6. In the liver, UCP mRNA expression did not differ among the quails and was not affected by environment or efficiency. However, comparisons of the low- and high-FE birds revealed higher levels of UCP mRNA in the muscle of low-FE birds.

7. COX III mRNA expression in the liver was dependent on environmental temperature and FE. Higher COX III mRNA expression was observed in animals that remained under comfortable conditions, and high-FE birds exhibited higher expression levels compared to low-FE birds.

8. These results suggest a correlation between IGF-I, GHR, ANT, UCP and COX III gene expression and FE and that environmental temperature could affect the expression of some of these genes.     

Inhibitory effects of epidermal growth factor on progesterone production of ovarian granulosa cells in Tsaiya duck (Anas platyrhynchos var. domestica)

1.?The purpose of this study was to investigate the effects of epidermal growth factor (EGF) on progesterone (P₄) secretion from ovarian granulosa cells in Tsaiya ducks (Anas platyrhynchos var. domestica).

2.?We obtained the largest (F1) follicle from Tsaiya duck, the granulosa layer was separated and the cells were isolated according to their proximity to the germinal disc.

3.?The granulosa cells were cultured in vitro, the culture media and the cells were used to determine P₄ and steroidogenic enzyme concentrations, respectively.

4.?P₄ concentrations were decreased in cultured granulosa cells taken proximal to the germinal disc (GD) compared to those distal to the germinal disc (NGD).

5.?EGF inhibited both basal and ovine luteinising hormone (oLH)-induced P₄ concentrations. It also inhibited the P₄ secretion via protein kinase A (PKA) pathway when cultured with GD and NGD granulose cells (mixed together) in vitro.

6.?Western blot results showed decreased concentrations of cytochrome P450 side-chain cleavage (P450scc) enzyme, 3β-hydroxysteroid dehydrogenase (3β-HSD) enzyme and steroid acute regulatory (StAR) protein expression, when the cells were co-treated with EGF and oLH.

7.?The inhibitory effect of oLH-induced P₄ production was attenuated by EGF by the addition of MAP-erk kinase (MEK) inhibitor (PD98059) suggests EGF may inhibit P₄ production by affecting via the mitogen-activated protein kinase (MAPK) pathway.     

Effects of arsenic supplementation in feed on laying performance,arsenic retention of eggs and organs,biochemical indices and endocrine hormones

1. The primary objective of this experiment was to estimate the toxic effects of arsenic (As) supplementation in feed on laying performance, As retention by eggs and organs, serum biochemical indices and endocrine hormones in laying hens.

2. A total of 320 “Jinghong Number 1” hens, 56-week-old, were randomly allocated into four treatments of four replicates with 20 layers in each. Graded arsenical was added to the basal diet in the experimental diets at As levels of 0, 17, 34 and 51 mg/kg, respectively. The trial lasted for 9 weeks including 1 week for acclimatisation.

3. Supplementation of dietary As for eight weeks had no effect on laying performance. As retention in albumen, yolk, egg, liver and kidney increased as As levels increased The level of serum phosphorus (P) was minimised at the 17 mg As/kg group. The activity of serum glutamic oxaloacetic transaminase (GOT) increased linearly. No differences were observed for levels of serum calcium (Ca), alkaline phosphatase (AKP) and serum glutamic pyruvic transaminase (GPT). Concentrations of estradiol (E₂) and progesterone (PG) declined at 34 and 51 mg/kg As levels compared with the control group. As supplementation exerted no influence on levels of serum follicle stimulating hormone (FSH), luteinising hormone (LH), triiodothyronine (T₃), thyroxine (T₄) and the ratio between T₃ and T₄.

4. In conclusion, dietary As supplementation accelerated retention in tissues and eggs, and affected the laying rate by diminishing hormone levels of E2 and PG at 51 mg/kg.     

Measurement of the respiratory metabolism of the fowl

1. The occurrence of low respiratory quotients (RQ) in fowls and the reliability of oxygen consumption, carbon dioxide output and heat production data in indirect calorimetry were studied.

2. The RQ, data from the gravimetric and the combined gravimetric‐volumetric systems were essentially the same, while differences in O₂ and CO₂ between the systems were primarily due to variations in environmental temperature.

3. Fasting RQ, was never less than 0.70 in these systems.

4. In the volumetric system the O₂, CO₂ and RQ, data from the diaferometer were significantly different from the infra‐red and paramagnetic analyses.

5. The CO₂ values from the diaferometer were correct, but the O₂ values were too low. In the specific analysers the reverse was seen, the paramagnetically‐determined O₂ values being correct and the CO₂ values from infra‐red analysis being too low.

6. Thus the fasting RQ values from the diaferometer were too high (0.762) and from the specific analysers too low (0.683).     

Molecular cloning,alternative splicing and mRNA expression analysis of MAGI1 and its correlation with laying performance in geese

1. In a previous study, a laying-related single nucleotide polymorphism (SNP) Record-106975 (A–G) was found in the intron of Membrane-associated Guanylate Kinase with Inverted Domain Structure-1 (MAGI1) gene by restriction site-associated DNA sequencing. This study was performed to further identify the function of MAGI1 on laying performance in Yangzhou geese.

2. The complete MAGI1 cDNA sequence was cloned from the ovary of the Yangzhou goose. A total of 4 alternative splice variants were identified, and the characterisation of their nucleic acid and amino acid (AA) sequences were analysed. The AA sequence of goose MAGI1 was highly conserved with other avian species.

3. MAGI1 was ubiquitously expressed in 11 tested tissues, with greater amounts of mRNA in the granulosa cell layer and ovary. GG (n = 14) and GA (n = 6) genotypes of SNP Record-106975 showed significantly lower MAGI1 mRNA levels than those of the AA genotype.

4. Over-expression and knockdown experiments revealed that MAGI1 mRNA expression was associated with caspase-3 mRNA levels in granulosa cells, and may play a role in regulating apoptosis of granulosa cells.     

The utilisation of goose egg nutrients by the developing embryo

1. Eggs and hatched embryos from geese were analysed for their proximate and amino acid composition. In comparison with eggs and embryos of the domestic fowl the following were found.

2. The yolk: albumen ratio of the goose egg was higher.

3. The fat concentration in the egg yolk and the protein concentration in the egg albumen were lower.

4. Deposition of dry matter in the embryo and energy expenditure during incubation were similar. In both species, the nitrogen in the embryo exceeded the nitrogen in the egg contents. This is probably due to the utilisation of egg‐shell membrane proteins.

5. Lysine concentration in the goose egg proteins was lower, which was reflected in the hatched gosling proteins.

6. There were high correlations in amino acid concentrations between chicken and goose eggs and between the efficiencies of amino acid utilisation by their embryos, implying that similar metabolic processes are involved in these two species.     

Lipopolysaccharide reduces food passage rate from the crop by a prostaglandin-independent mechanism in chickens

1. We examined the effect of lipopolysaccharide (LPS), a component of Gram-negative bacteria, on food passage in the digestive tract of chickens (Gallus gallus) in order to clarify whether bacterial infection affects food passage in birds.

2. Food passage in the crop was significantly reduced by intraperitoneal (IP) injection of LPS while it did not affect the number of defecations, suggesting that LPS may affect food passage only in the upper digestive tract.

3. Similar to LPS, prostaglandin E2 (PGE2), one of the mediators of LPS, also reduced crop-emptying rate in chickens while it had no effect on the number of defecations.

4. Pretreatment with indomethacin, which is an inhibitor of cyclooxygenase (COX), a prostaglandin synthase, had no effect on LPS-induced inhibition of crop emptying.

5. IP injection of LPS did not affect the mRNA expression of COX2 in the upper digestive tract of chickens.

6. It is therefore likely that LPS and PGE2 reduced food passage rate in the crop by a prostaglandin-independent pathway in chickens.     

Paired box 7 (Pax7) gene: molecular characterisation,polymorphism and its association with growth performance in goose (Anser cygnoides)

1. Paired box (Pax7) gene is a member of the paired box family and plays a critical role in animal growth and muscle development. However, the molecular characterisation of the goose Pax7 gene is unknown.

2. The open-reading frame of goose Pax7 is composed of 1509 bp, which encodes a protein of 503 amino acids and shares high homology with Pax7 of other birds.

3. Ten single-nucleotide polymorphisms were identified in the genomic DNA sequence, 8 located in the intron region and two located in the exon region.

4. Association analysis showed the C122T locus was significantly associated with the body weight of Zhedong-White geese in week 4, 6, 8, 10 and 12.

5. It was concluded that the goose Pax7 gene may be an important candidate gene for goose growth traits and marker-assisted selection.     

Precocious puberty in tamoxifen‐treated cockerels: Hypothalamic gonadotrophin‐releasing hormone‐I and plasma luteinising hormone,prolactin, growth hormone and testosterone

1. The administration of the anti‐oestrogen, tamoxifen (TAM) to juvenile chicks results in precocious puberty. In the present study the effects of TAM administration (1 mg/kg body weight on alternate days from 12 d of age) on testicular function, hypothalamic chicken gonadotropin‐re‐leasing hormone (cGn‐RH‐I), plasma luteinising hormone (LH), growth hormone (GH), prolactin (PRL) and testosterone were studied in juvenile White Leghorn cockerels.

2. The increase in hypothalamic GnRH‐I content which occurs during sexual development was advanced in TAM‐treated birds, in association with precocious testicular development, an early rise of plasma testosterone content and enhanced comb growth.

3. Plasma LH concentrations behaved similarly and were higher in the TAM‐treated than in control birds, during most of the experimental period. Plasma PRL concentration, which is high at hatching, decreased more quickly in TAM‐treated than in control birds; plasma GH values were not consistently affected by TAM treatment.

4. Both the growth and the involution of the bursa of Fabricius in the TAM‐treated cockerels preceded that in the control chicks.

5. It is concluded that TAM treatment induces precocious puberty in the cockerel by blocking the negative feedback action of aromatised testicular androgens on the hypothalamus.     

Development and validation of a homologous radioimmunoassay using a biologically active recombinant turkey prolactin

1. A new homologous radioimmunoassay has been developed for the measurement of turkey prolactin.

2. A 25000 kDa purified recombinant derived turkey prolactin (rtPRL), the biological activity of which was tested using a crop sac assay, was used as immunogen for the production of rabbit antiserum. In this biological test, the rtPRL was as active as the ovinePRL.

3. The radioligand (rtPRL) was labelled with ¹²⁵I and the assay allowed the detection of standard doses of rtPRL ranging from 400 pg/tube to 50 ng/tube.

4. No cross reaction with chicken luteinising hormone and recombinant chicken growth hormone was detected.

5. The within and between assay coefficients of variability were 5.0 ± 2.7% and 16.3%, respectively. The overall mean recovery ratio was 1.01.

6. The dose‐response curves obtained with serial dilution of plasma and pituitary from turkey hens at different physiological stages and from male turkeys were parallel to those obtained with standard rtPRL.

7. The measured concentration of prolactin was 5 times higher in plasma from incubating than laying turkey hens, and the pituitaries from incubating hens contained 2 and 4 times more prolactin than those of laying and out of lay hens or males, respectively.

8. To further assess the validity of the assay, we measured changes in plasma concentration of prolactin in turkeys following stimulation with chicken vasointestinal peptide (cVIP). A single injection of 1 or 10 μg/kg body weight of cVIP to laying hens produced a large and rapid increase in plasma prolactin.

9. This new radioimmunoassay appears to be highly specific and sensitive for the measurement of turkey prolactin.     

Selection for food conversion in broilers: Direct and correlated responses to selection for body‐weight gain,food consumption and food conversion ratio

1. Direct and correlated responses were determined after five generations in four lines of chickens selected either for increased body‐weight gain (line W), for increased food consumption (line F), for decreased food conversion ratio (line E), or at random (line C).

2. Realised heritability estimates calculated after five generations of selection were : 0–37 + 0.04 for weight gain (WG); 0.44 + 0.05 for food consumption (FC); 0.21 + 0.04 for food conversion ratio (FCR).

3. Realised genetic correlation estimates were: WG and FC, +0.71 ±006; WG and FCR, ‐0.40±0.09; FC and FCR, +0.27 + 0.09.

4. Zero‐generation heritability and genetic correlation estimates were greater than the realised estimates, and sex linkage appeared to be important in the expression of all three traits.

5. The genetic correlation between FC and FCR was asymmetrical with considerable positive response in FCR in line F (r_g = +0.79) but negligible response in FC in line E (r_g = —0.01).

6. There was an apparent plateau in response in FCR in line E from the third to the fifth selected generations.     

Prevalence of and risk factors for Campylobacter colonisation in broiler flocks at the end of the rearing period in France

1. A study was conducted to estimate the prevalence and quantification by species of Campylobacter infection in broiler flocks at the end of the rearing period and to identify associated risk factors.

2. A questionnaire about the rearing period was completed and caecal samples were collected from 121 broiler flocks in Brittany, France, during 2008.

3. Campylobacter was isolated in 87 out of 121 flocks – a prevalence of 71.9% (95% CI, 63.7–80.1%), including 40.5% of Campylobacter jejuni and 29.8% of Campylobacter coli.

4. The average concentration, in positive flocks, was 7.96 log₁₀ cfu/g and ranged from 3.15 to 10.32 log₁₀ cfu/g.

5. The average concentration by species was: 7.57 log₁₀ cfu/g for C. jejuni and 8.44 log₁₀ cfu/g for C. coli.

6. There was a seasonal effect, with increased risk of Campylobacter colonisation in June, July and August (odds ratio (OR) = 9.59, 95% CI 1.15–79.75).

7. The other factors, associated with lower risk of Campylobacter colonisation, were the acidification of drinking water (OR = 0.33, 95% CI 0.13–0.86), antibiotic treatment at the beginning of the rearing period (OR = 0.20, 95% CI 0.07–0.55) and rodent control around the house (OR = 0.18, 95% CI 0.03–0.95).

8. The results show that hygiene practices and biosecurity measures could lead to a reduction in Campylobacter colonisation.