Estradiol-17ß Is Influenced by Age, Housing System, and Laying Performance in Genetically Divergent Laying Hens (Gallus gallus f.d.)

The estrogen estradiol-17ß is known as one of the major gonadal steroid hormones with different functions in reproduction. In this study we analyzed estradiol-17ß concentration in laying hens of four pure bred chicken laying lines at four different time intervals of the laying period (17th-19th week of age, 33rd-35th week of age, 49th-51st week of age, and 72nd week of age). The high performing white egg (WLA) and brown egg (BLA) layer lines as well as the low performing white (R11) and brown (L68) layer lines were kept in both single cages and a floor housing system. We investigated whether there were differences in estradiol -17ß concentrations between lines at different ages that could be related to selection for high egg production or phylogenetic origin of the animals, and whether there was an influence of housing conditions on estradiol-17ß. Estradiol-17ß concentrations differed between high and low performing layer lines at all time intervals studied. High performing hens showed higher estradiol-17ß concentrations compared to low performing hens. In all lines, highest estradiol-17ß concentration was measured at their 49th to their 51st week of age, whereas the peak of laying intensity was observed at their 33rd to their 35th week of age. Additionally, hens with fewer opportunities for activity housed in cages showed higher estradiol-17ß concentrations than hens kept in a floor housing system with more movement possibilities. We could show that laying performance is strongly linked with estradiol -17ß concentration. This concentration changes during laying period and is also influenced by the housing system.

[Meat quality in broilers reared in different housing systems]

Meat quality was assessed in Cobb-500 cage vs. floor-housed broilers slaughtered at 38 vs 49 days of age. Broilers (105 birds per housing system) were reared since 1 day of age in conditions of vivarium of Center for Selection and Genetics «Zagorskoye EPH». Fat content in breast meat was significantly higher (p<0.05) at both slaughter ages in cage-housed broilers (2.0 and 2.7% at slaughter age 38 and 49 days, respectively) compared to floor-housed (1.6 and 2.2%). Protein content in breast meat was higher in floor-caged broilers. Total collagen content in thigh meat of floor housed broilers (789.88 mg/100 g) was 1.5 fold higher compared to cage-housed (515.80 mg/100 g, p<0.05). Fatty acid profiles of meat were mostly affected by the type of meat (red vs white) and to a lesser extent by housing system and slaughter age. Water-holding capacity in red meat significantly differed between slaughter ages and between housing systems at slaughter age 38 days (р<0.05): at slaughter age 38 days water-holding capacity in red meat was 67.3 in cage-housed broilers vs. 70.1% in floor-housed; at slaughter age 49 days 74.9 vs. 76.0%, respectively. The five-point scores of sensory taste evaluation for the meat of floor-housed broilers (4.55 and 4.91 for breast meat at slaughter ages 38 and 49 days; 4.40 and 4.90 for thigh meat) were better compared to cage-housed (4.47 and 4.83 for breast meat at slaughter ages 38 and 49 days; 4.37 and 4.70 for thigh meat). The conclusion was made that meat quality estimated by a set of the relevant parameters was marginally better in floor housed broilers in compare to cage-housed.

Opinion of Belgian Egg Farmers on Hen Welfare and Its Relationship with Housing Type

Simple Summary

Until 2012, laying hens in the EU were often housed in conventional cages that offered limited space and few opportunities to perform highly motivated behaviors. Conventional cages are now banned in the EU in order to improve animal welfare. In this study, egg farmers were surveyed (winter 2013–2014) to assess whether they perceived any changes in animal welfare since changing housing systems, what role hen welfare played in choosing a new housing system, and which aspects of hen welfare they find most important. The data show that the answers differ depending on which housing system the farmers currently use and whether they had used conventional cages in the past.

Abstract

As of 2012, the EU has banned the use of conventional cages (CC) for laying hens, causing a shift in housing systems. This study’s aim was to gain insight into farmers’ opinions on hen health and welfare in their current housing systems. A survey was sent to 218 Belgian egg farmers, of which 127 (58.3%) responded, with 84 still active as egg farmer. Hen welfare tended to be less important in choosing the housing system for farmers with cage than with non-cage systems. Respondents currently using cage systems were more satisfied with hen health than respondents with non-cage systems. Reported mortality increased with farm size and was higher in furnished cages than in floor housing. Feather pecking, cannibalism, smothering and mortality were perceived to be higher in current housing systems than in CC, but only by respondents who shifted to non-cage systems from previously having had CC. Health- and production-related parameters were scored to be more important for hen welfare as compared to behavior-related parameters. Those without CC in the past rated factors relating to natural behavior to be more important for welfare than those with CC. This difference in opinion based on farmer backgrounds should be taken into account in future research.

Survey of egg farmers regarding the ban on conventional cages in the EU and their opinion of alternative layer housing systems in Flanders, Belgium

On 1 January 2012, conventional cages for laying hens were banned in the European Union (EU); all egg farmers must now use alternative hen housing systems. In total, 218 Flemish egg farmers were surveyed in 2013 to 2014 regarding which housing systems they currently use, their degree of satisfaction with the system, and how they experienced the transition from conventional cages to an alternative system. The response rate was 58.3% (127 respondents). Of these, 43 (33.9%) were no longer active as an egg farmer, mainly due to the ban on conventional cages. The respondents who were active as egg farmers both before and after the transition (84, 66.1%) mainly judged the ban as negative for their own finances and for the competitive position of the Belgian egg industry, but were neutral or positive regarding the general consequences for their own business. Most respondents' hens were housed in either aviary systems (47.7%) or in alternative cage systems (38.2%). When choosing a new system, the fit into the farm and consumer demand were the most important factors. Consumer demand was the main reason for choosing a system with free-range access. In general, egg farmers were satisfied with the system they chose, although this differs between systems. When asked to compare the alternative systems to conventional cages, alternatives were judged to be better for hen welfare and consumer demand, but similar or worse for all other aspects, especially labor. Egg farmers previously using conventional cages judged alternative systems more negatively than those who had no prior experience with conventional cages. Farmers who had experience with free-range systems judged these more positively than those without this experience, e.g., for egg consumer demand, profitability, and hen welfare. These results can possibly be extrapolated to other EU countries in which conventional cages were the most common housing system until 2012, and lessons can be drawn from the farmers' experiences when implementing other animal welfare legislation that may require similar far-reaching adaptations for primary production.