4.3 Transport

System
Type of doors
Number of birds/crate
Climate control on the truck
Vibrations
Duration of the journey
Facilities (access to water/feed)
Climate during transport
Further reading
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System

Kristensen et al. (2001) evaluated a modular system for depopulating battery cages and found a significant reduction in the time each bird was handled from 64.5 s to 4.5 s. Compared with manual handling there was no difference in the proportion of damaged birds in the small trial, but the catchers preferred the modular system.

Van Niekerk et al. (2014) found that the use of carts to bring crates into the henhouse reduced the percentage of damaged birds in the slaughter plant.

Type of doors

Crates or modules with large doors will reduce the risk of broken wing. Sliding doors may reduce the incidence of trapped birds.

Number of birds/crate

The number of birds per crate influences the microclimate around the birds. Higher stocking densities may be used in winter, but precautions should be taken for those birds during the time in lairage as temperatures may get too high. Based on recent research (Richards et al., 2012) there is a strong argument for using different stocking rates in different areas of the load (in particular for reduced numbers in drawers at the top-front of the load) if this could be achieved in practice.

Delezie et al (2007) found that stocking density during transit had a greater influence on levels of stress in broilers than feed withdrawal or transportation. The stocking densities recommended by European legislation (EC, 2005) may be used as a guide that needs adjusting according to weather, bird condition and journey duration.

Guideline of space allowances for poultry in transit (EU, 2005)

Weight of poultry (kg)	Space allowance (cm²/kg)
Chicks (day old)	21-25 cm²/chick
<1.6	180 – 200
1.6 – 3.0	160
3.0 – 5.0	115
> 5.0	105

Climate control on the truck

All studies addressing climate during transport found a large variation depending on the position on the truck (Webster et al., 1992; Kettlewell et al., 1993; Weeks et al., 1997; Richards et al., 2012), with naturally ventilated trucks showing the largest variation. Therefore temperature control on trucks is essential to maintain temperatures at an acceptable level. To realise this for all birds, temperature recording should be done on all trucks on various locations on the truck in close vicinity to the birds. Temperatures should be both recorded and linked to an in-cab monitoring and alarm system. As a guide, that should be modified according to individual loads and vehicle designs, Weeks et al (1997) indicated poorly-feathered end-of-lay birds at 22-28^oC were likely to be thermally comfortable at the usual high stocking densities. EFSA (2011) recommended that specific thermal limits should be defined. In winter it is especially important to minimise wind chill by the use of curtains and parking in the lea of buildings or trees and to avoid birds becoming wet.

By means of trailer roof vents and side curtains on-board temperature can be varied and maintained within acceptable limits (Burlinguette et al., 2012). during milder ambient conditions (9.8°C) on-board temperature ranged between 10.3 and 16.7°C if both vents and curtains were open. As external temperatures dropped, the side curtains and some of the roof vents were closed. This resulted in increasingly variable and more extreme thermal conditions, with heat and moisture accumulated along the mid-line of the load near the front of the lead trailer and near the back of the rear trailer. At an ambient temperature of -22.1°C, temperatures within the trailer varied widely between -20.7 to 21.7°C with an estimated 58.6% of the load volume being exposed to temperatures below 0°C. In addition, the trailer humidity ratio rose and conditions approached saturation (relative humidity>80%) in 55.2% of the load volume. Rectal temperatures showed that during winter weather in Canada, when the trailer is closed up and tarped, both hypothermia and hyperthermia occurred within the same trailer (Knezacek et al., 2010).

Vibrations

Chickens find vibration below 5 Hz particularly aversive, Randall et al. (1997) concluded that the resonant frequencies of 1-5 Hz found on transporters are undesirable. Thus vibration should be reduced, for example by using air suspension. Appropriate methodology to compare aversiveness of concurrent stressors during transport is being developed, initially using thermal and vibrational stressors (e.g. MacCalium et al., 2003).

Duration of the journey

Typical times in transit are unreported in most countries, but vary considerably. A small study of 24 commercial end-of-lay hen journeys in the UK found mean marketing time to range from 5.4 – 17.6 h (Richards et al., 2012). In the USA and Canada a review of DOAs (birds dead on arrival) by Newberry et al., (1999) found a substantial increase in hen mortality with marketing time for example from 0.7% (under 12 h) to 9.9% (over 24 h). A study in The Netherlands on 24 commercial layer flocks revealed a journey time of on average 2 hours and a total transport duration (thus including time in lairage) of on average 10 hours (Van Niekerk et al., 2014). These flocks were all slaughtered in the same plant in the Northern part of The Netherlands. Flocks located in the southern part are mostly slaughtered in Belgium and journey times will be limited. Some of the Dutch flocks are slaughtered in Eastern Europe (e.g. Poland), resulting in long journeys and even longer transport durations.

Facilities (access to water/feed)

In general no food or water is supplied to end-of-lay hens during the journey. However, for long journeys water supply is obligatory on the trucks and for even longer distances also food should be supplied.

For transport of pullets and breeding stock water supply systems have been developed for application on trucks. Mostly these comprise a water tank connected with tubes to fixed water systems in container units. For providing water to birds in crates different systems are used. These consist of loose tube systems that are attached to the crates. Side branches with nipple drinkers are stuck into the crates. The system is placed after the crates are loaded on the truck and is connected to a water tank on the truck.

Figure: Drinking water into crates on a truck

A Dutch slaughter plant has water supply for end-of-lay hens in the lairage. This is realized by sliding tubes with nipple drinkers between the crates.

Figure: Drinking water into crates at lairage

Solid food is never supplied to birds on transit. Apart from the issue of soiling with manure, experts indicate that birds on transport easily vomit and can choke in the food. Instead liquid nutrients are added to the drinking water.

Climate during transport

EFSA (2011) advices specific temperature limits during transport. They regard 24 – 25°C in the containers as a maximum for broilers, at a relative humidity of 70%. EFSA also advices to use mechanical ventilation for transports over 4 hours. Weeks et al. (1997) indicate that air velocity during transport should be 0.3 – 1.0 m/s at environmental temperatures of 10 – 15°C for broilers and 22–28°C for poorly feathered laying hens. Stocking density in the crates plays an important role and should be adjusted according to body weight of the birds and climatological circumstances (Mitchell and Kettlewell, 1998).