Search

Studies on the prevalence of feather pecking in different commercial laying hen 23 systems and its welfare and economic impacts are reviewed in the following paper. 24 Current methods for controlling feather pecking include beak-trimming and alterations to light regimes, but these methods have significant disadvantages from the perspective of bird welfare. A substantial body of research has now identified risk factors for feather pecking during both the rearing and laying periods. It is argued that these findings can be translated into optimised management practices that can prevent and control feather pecking whilst simultaneously conferring welfare benefits. The genetic basis of feather pecking is considered, and studies that suggest group selection techniques could produce birds with a reduced tendency to feather peck in commercial flocks are highlighted. Keywords: laying hen; feather pecking; beak-trimming; light; risk factor; genetic selection

Data from ten sources comprising 3,851 flocks were modelled to identify variation in levels of mortality in laying hens. The predicted increase with age was curvilinear with significant variation between the seven breed categories. Mortality was higher in loose housing systems than in cages and variable within system, confirming previous reports. Cumulative mortality (CM) was higher in flocks with intact beaks (χ2 = 6.03; df 1; p = 0.014) than in those with trimmed beaks. Most data were available for free-range systems (2,823 flocks), where producer recorded CM at 60-80 weeks of age averaged 10% but with a range from 0% to 69.3%. Life cycle assessment showed that the main effect of increased levels of hen mortality is to increase the relative contribution of breeding overheads, so increasing environmental burdens per unit of production. Reducing CM to levels currently achieved by the 1st quartile could reduce flock greenhouse gas emissions by as much as 25%. Concurrently this would enhance hen welfare and better meet the expectation of egg consumers. More research to understand the genetic x environment interaction and detailed records of the causes of mortality is required so that improved genotypes can be developed for different systems and different breeds can be better managed within systems.

Injurious pecking remains one of the biggest problems challenging free range egg producers, with both economic implications for the farmer and welfare implications for the birds. The most widespread form of injurious pecking is feather pecking, the most damaging form of which is severe feather pecking (SFP) which has, as yet unclear, links with gentle feather pecking (GFP). The current prospective epidemiological study investigates the development of GFP and SFP on 61 free range and organic UK farms (111 flocks). Flocks were visited at 25 (20–30) and 40 (35–45) weeks, when rates of GFP and SFP respectively and levels of feather damage were recorded. Environmental and management data were collected for each flock. Factors affecting the development of these behaviours were modelled using the multilevel modelling program, MLwiN (Rasbash et al., 2004). GFP was observed in 89.2% and 73% of flocks at 25 and 40 weeks, respectively, at a mean rate of 0.65bouts/bird/h. GFP rates decreased with increased percentage range use (coeff.: −0.001±0.0006, p =0.025) and temperature inside the laying house (coeff.: −0.005±0.001, p =0.001). GFP was higher in flocks with soil or grass litter ( χ 2 =13.16, df=4, p =0.012), flocks which had no perch access (0.010±0.001 vs. 0.007±0.002bouts/bird/min, p =0.047) and flocks which were beak trimmed compared to those non-beak trimmed or retrospectively beak trimmed (0.013±0.002 vs. 0.003±0.001 and 0.002±0.001, p =0.007). SFP was observed in 68.5% and 85.6% of flocks at the 1st and 2nd visits, respectively, at a mean rate of 1.22bouts/bird/h. SFP rates decreased with range use (coeff.: −0.001±0.0003, p =0.003). Mean rates were highest in non-beak trimmed compared to beak trimmed flocks (0.032±0.003 vs. 0.017±0.003bouts/bird/min, p =0.028), flocks observed to be feather pecking when they arrived on farm compared to those that were not (0.062±0.018 vs. 0.019±0.002bouts/bird/min, p =0.001), and flocks fed pelleted compared to those fed mashed food (0.042±0.002 vs. 0.016±0.002bouts/bird/min, p =0.005). Plumage damage was lower in beak trimmed compared to non-beak trimmed flocks (plumage score 1.00±0.0001 vs. 1.15±0.068, p =0.040), and flocks which were fed mashed feed, and showed a quadratic relationship with severe feather pecking ( p =0.003) which was positive over the observed ranges of the behaviours. In commercial situations, feeding mashed feed and increasing range use may reduce severe feather pecking and therefore feather damage.

SUMMARYA survey ofCoxiella burnetiiinfection (Q fever) in sheep flocks and goat herds in Great Britain was undertaken. A total of 5791 sheep (384 flocks) and 522 goats (145 herds) were examined forC. burnetiiantibodies using an ELISA. Overall, 53 sheep (37 flocks), and four goats (four herds), tested positive. Estimates of individual animal, between-flock/-herd and within-flock/-herd crude prevalences were 0·9%, 10·2% and 9·0%, respectively, for sheep, and 0·8%, 3% and 26·3%, respectively, for goats. With sheep, the likelihood of an animal testing positive increased with total flock size (P= 0·002) and number of breeding ewes in the flock (P= 0·021). It also increased with number of goats within a 10 km radius (P= 0·038). There was no evidence for spatial clustering of positive herds above that expected by chance alone. No analysis of risk factors was attempted for goats because of the paucity of positives.

A serological survey of Toxoplasma gondii infection in adult breeding sheep in Great Britain was conducted using surplus sera taken during a seroprevalence study of Brucella melitensis in 2009. Of the 3539 sera collected from 227 flocks, 2619 (74 per cent) were found to be positive for T gondii specific antibody when tested using latex agglutination. Multilevel logistic modelling suggested that the likelihood of infection increased with age and this effect appeared to be amplified in animals vaccinated against T gondii. The model also indicated that the odds of sheep being seropositive were increased on premises where cattle were also kept. These results suggest a high level of Toxoplasma infection in breeding sheep in Great Britain and provide further evidence to suggest that postnatal infection is more common than congenital infection in sheep.

This study investigated the protective effects of an on-farm management package designed to reduce injurious pecking (IP) in loose-housed laying hens. A systematic review of scientific literature generated 46 potentially protective management strategies. Bespoke management packages were designed for treatment flocks (TF) using these management strategies. IP in 53 TFs was compared with IP in 47 control flocks (CF) where the management package was not employed. Scoring of plumage damage (PD) and observations of gentle and severe feather pecking (GFP; SFP), and vent and cannibalistic pecking (VP) were completed, and management strategy use was recorded, at 20, 30 and 40 weeks of age. Differences between treatment and CF were examined using multilevel modelling. Compared with CF, TF employed more management strategies (P