Relationships between range access as monitored by radio frequency identification technology, fearfulness, and plumage damage in free-range laying hens

Abstract

Severe feather-pecking (SFP), a particularly injurious behaviour in laying hens (Gallus gallus domesticus), is thought to be negatively correlated with range use in free-range systems. In turn, range use is thought to be inversely associated with fearfulness, where fearful birds may be less likely to venture outside. However, very few experiments have investigated the proposed association between range use and fearfulness. This experiment investigated associations between range use (time spent outside), fearfulness, plumage damage, and BW. Two pens of 50 ISA Brown laying hens ( n = 100) were fitted with radio frequency identification (RFID) transponders (contained within silicone leg rings) at 26 weeks of age. Data were then collected over 13 days. A total of 95% of birds accessed the outdoor run more than once per day. Birds spent an average duration of 6.1 h outside each day over 11 visits per bird per day (51.5 min per visit). The top 15 and bottom 15 range users (n = 30), as determined by the total time spent on the range over 13 days, were selected for study. These birds were tonic immobility (TI) tested at the end of the trial and were feather-scored and weighed after TI testing. Birds with longer TI durations spent less time outside ( P = 0.01). Plumage damage was not associated with range use ( P = 0.68). The small group sizes used in this experiment may have been conducive to the high numbers of birds utilising the outdoor range area. The RFID technology collected a large amount of data on range access in the tagged birds, and provides a potential means for quantitatively assessing range access in laying hens. The present findings indicate a negative association between fearfulness and range use. However, the proposed negative association between plumage damage and range use was not supported. The relationships between range use, fearfulness, and SFP warrant further research.Keywords: radio frequency identification, range use, free-range, plumage damage, fearfulness Implications Free-range egg production has been increasing in recent years in a number of countries. However, little is known about ranging behaviour in laying hens. Severe feather-pecking (SFP), which may be associated with reduced range use, poses a significant risk to hen welfare and productivity in non-cage housing systems. This experiment successfully collected data on the range use of individual birds, via radio frequency identification technology, and fearfulness was negatively associated with range use. An improved understanding of range use and other behavioural correlates may allow enhanced management and housing, and enable the eventual control of SFP, a highly deleterious behaviour in the egg industry. IntroductionSevere feather-pecking (SFP) is a highly prevalent and extremely injurious behaviour in laying hens. It causes serious negative impacts in the egg industry, in terms of both animal welfare and production efficiency. SFP is multifactorial, with contributing factors including environmental, social, genetic, and nutritiona...

Individual Ranging Behaviour Patterns in Commercial Free-Range Layers as Observed through RFID Tracking

“…The present results are similar to previous research using individual tracking of hens in both experimental and commercial conditions. While monitoring pop hole use in experimental flocks, 80% of the hens were found to access the pop holes on at least 50% of the days [11], whereas when tracking individual hens in experimental flocks similar to our study, up to 85% of hens were found to access the range on most days [12], and between 66.5% and 80.5% of hens accessed it daily [14]. In commercial Swiss flocks, 79%–99% of the tracked hens were found to access the veranda at least once, and 47%–90% of tracked hens accessed the range beyond the veranda at least once [15].…”

“…It is unlikely that the RFID tracking system altered the hens’ ranging behaviour during the study, as others have examined the effect of the system on ranging behaviour and found no significant changes with or without the system [12,17]. We cannot rule out that installing temporary fences to form an ‘experimental pen’ and thereby reducing the size of the flock changed the ranging behaviour of the hens.…”

“…The question of how many and how much hens access the range is central to free-range housing systems and has been investigated in a number of recent studies in both experimental and commercial flocks [2,3,4,5,6,7,8,9,10,11,12,13,14,15]. Assessing the use of the range in hens has traditionally been done through point sampling observation methods of the entire flock at one point in time or an average over time.…”

“…Radio Frequency Identification Technology (RFID) is currently the most popular method of tracking individual hens and has been implemented in both experimental and commercial flocks [2,3]. In experimental flocks, approximately 80% of the flock has been found to access the pop hole [11], and 50% to 90% of the flock will access the range [12,13,14]. Moreover, in these studies, distinct groups of hens (low and high users of the range) have been identified, indicating that there is marked variation between individual hens in terms of range use.…”

“…These initial studies using RFID tracking of free-range laying hens indicate that while most hens use the outdoor area, there is considerable variation between individuals within a flock in terms of range use. Individual tracking of hens can also allow for examining patterns of range use, such as time of first access to the range [15] and variation due to time of day and weather [16] on frequency and duration of range access [12,15,17]. Fowl, both domestic and wild, are more active in the morning and evening periods of the day.…”