ANIMAL-BASED INDICATORS FOR ON-FARM WELFARE ASSESSMENT IN POULTRY

Improvements in poultry welfare are essential to ensure the quality of bird’s lives, but also may have fruitful outcomes to industry for minimizing the economic losses impacts under better bird performance, and carcass quality with reductions of mortality and condemnations. In fact, adopting a valid, reliable, and feasible welfare assessment protocol on-farm is fairly valuable method not only addressed to poultry welfare, but also, to industries interests, and consumer demands. Several array internal and external identified factors can largely influence the welfare and health evaluation of turkey flocks. The present study focuses mainly on the development of a welfare assessment protocol on-farm based on animal-based indicators. These parameters were carefully reviewed and critically tested. In Chapter 1 and 2, the aim was to do a literature review on animal-based indicators for turkeys (Meleagris gallopavo), gathering information about promising indicators that could be included into an on-farm welfare assessment protocol. Social, environmental variables and pathological findings were pointed out as factors affecting behavior and welfare of turkeys that may be relevant economically to the commercial production systems. In Chapter 3, the walks through following line transect methodology used in wildlife studies was adapted to explore their feasibility as a welfare assessment tool. The aim of this study was to compare broiler welfare assessed by individual sampling and transect walks. Six managed flocks were evaluated. Measures on 150 birds were carried out for the individual sampling. Observers walked slowly on random order paths and recorded the incidence of immobility, lameness, dirtiness, sick, agony and dead birds. It was possible to detected small variations across farms (P < 0.003) in the prevalence of most welfare indicators and consistency in inter-observer reliability (P ≥ 0.05). Surprisingly, both methods differed greatly in the frequency of the studied parameters. Possibly, the transect walks might have overlooked walking impairs due to a large number of birds. Another hypothesis may be related to biased individual sampling procedures. In Chapter 4, the study investigated the feasibility of the transect walks method as a novel approach to on-farm welfare assessment of male and female commercial turkey flocks in Italy. This is the first report of welfare assessment using the transect walks method in Europe at turkey farms. A total of 25 commercial [B.U.T.] - Big 6) turkey flocks (15 male and 10 female) with similar management standard procedures were evaluated. Incidence of birds falling into any of the welfare categories was recorded. The studied indicators were: immobility, lameness, wounds, featherless, small size and serious health issues in the flocks, for instance, sick, terminally ill and dead. In addition, behavioral variables as aggression towards mate, interaction with humans and mating were also considered. Sensitivity of the method was noted by effect of sex (P < 0.001) for immobility, lameness, wounds and dirtiness indicators. In addition, inter-observer reliability (P ≥ 0.05) was also consistent for almost the studied variables. Male birds showed high incidence of immobility (0.14% ± 0.02% vs. 0.02% ± 0), lameness (9.06% ± 0.41% vs. 4.34% ± 0.20%), wounds (3.54% ± 0.19% vs. 1.38% ± 0.09%) and dirtiness (0.20% ± 0.02% vs. 0.07% ± 0.01%) than female flocks, respectively. Transect walks approach is an essential component, indeed, to improve the welfare assessment on-farm level. It showed to be a valuable alternative method at commercial strains of meat turkeys. Thus, this innovative method fulfills some industries and producers requirements, such as, no bird disturbing or animal catching with decreased of time-consuming and personnel involved, and no extra costs required, at its application at commercial practices. Some further research should be done to fill the complex gaps and improve the welfare protocol introduced herein.