Visual Access to an Outdoor Range During Rearing Boosts Ranging Behaviour of Meat Chickens

Frequent visits to an outdoor range has been associated with good meat chicken welfare but not all chickens will access the outdoor range when provided with the opportunity (Taylor et al., 2018). On average, it takes an average of three to four days for most meat chickens in commercial conditions to access the range after the pop-holes first open (Taylor et al., 2017a). Yet chickens that access the range soon after the pop-holes first open, range more frequently throughout their lives compared to chickens that take a longer time to first access the range (Taylor et al., 2017b). Therefore, reducing the latency to first access an outdoor range may be key to optimising ranging behaviour and subsequently improving bird welfare. A critical step in reducing the latency to range may be ‘preparing’ the birds to range. The indoor housing environment prior to range access is typically simple and predictable until pop-hole doors open, usually at 21 days of age. Providing more environmental complexity and novelty during rearing may allow meat chickens to better adapt to the abrupt change in environment when range access is available, reducing the time taken for chickens to access the range and improving life time ranging behaviour. We provided complexity and novelty during rearing with the aim to optimise meat chicken ranging behaviour, specifically to reduce latency to range and increase the number of birds that ranged, the time spent on the range and the distance ranged.

Day old, mixed sex Cobb500 (n = 450) were housed in groups of 25 across 18 pens and were randomly allocated to one of three treatments. Controlled rearing (CON) was reflective of industry standard conditions and included wood shaving litter, feed and water. Visual access rearing treatment (VA) was the same as the control with addition of visual access to the range via transparent pop-hole covers. The complex rearing treatment (COMP) was the same as control with the addition of visual barriers, artificial haybales and fans with streamers. Range access was provided daily from 21 days of age and individual range use was tracked via RFID until 42 days of age. The proportion of birds that accessed the range was analysed with a GLMM with a binomial distribution. Latency to access the range was analysed with a Cox Regression and time spent on the range and number of days the range was accessed was analysed with a GLMM with a Gaussian distribution. Sex was included in all models.

VA birds accessed the range earlier (3.1 ± 0.5 days) than CON (6.3 ± 0.7 days) and COMP (9.1 ± 0.8 days) birds (F_(2,187)12.2, P < 0.001). A greater proportion of VA birds accessed the range (94.8%) compared to COMP birds (78.9%; F_(2,270)11.5, p = 0.003) but CON (89.5%) did not differ to any group. Few birds ventured further than 5 m from the shed (5.9% of all birds), but more CON (8.1%) and VA (9.3%) birds accessed the range area further from the shed (> 5m) compared to the COMP group (0.0%; χ²_(2,273)8.5, p = 0.015). There was a trend for VA birds to spend more time on the range (F_(2,16)3.4, p = 0.058). Birds from the VA group accessed the range on more days (13.7 ± 0.7 days) than CON (9.9 ± 0.7 days, p = 0.016) and COMP birds (7.6 ± 0.7 days, p = 0.002).

These results demonstrate that providing meat chickens with visual access to the outdoor range during rearing resulted in earlier range use and more days on the range than birds reared in typical industry conditions or when provided with environmental complexity. Therefore, visual access to an outdoor range is an effective method to improve ranging behaviour of meat chickens.