Research review: What's new in poultry housing and equipment?

With animal welfare and the environmental aspects of food animal farming gaining more attention from the public and high feed prices focusing efforts on getting the best performance from poultry, researchers have been active in studying the impacts of new developments in housing and equipment on the health, welfare and productivity of our birds. Senior editor, Jackie Linden, has selected some highlights of recently published work that have practical application today.

Housing systems and their impact on the reproductive health of hens

Physiological impacts on the reproductive capacity of hens housed in battery cages, cage-free and freerange systems were similar, according to a study at North Carolina State University.

Contrary to the popular belief that free-range or cage-free environments provide healthier production alternatives than conventional battery cages, the researchers comment that overall, there was no suggestion there is a significant positive physiological impact on the reproductive capacity of hens housed in these alternative production environments. Researchers did find that free-range birds had less healthy oviducts than those kept in the other systems, with a higher prevalence of tumours.

Correct positioning of nests and drinkers in aviaries

Researchers at the Centre for Proper Housing for Poultry and Rabbits in Switzerland have examined the influence of nest location and the placement of nipple drinkers on nest use by laying hens in an aviary.

In a commercial aviary, nests were placed along the walls in 10 pens, and nipple drinkers were installed in front of the nests in five of these pens, while the other 10 pens were equipped with nests placed on a tier within the aviary (integrated nests), with nipple drinkers also positioned in front of half of them.

Nest location affected the birds’ stationary and locomotive behaviour in front of the nests; hens in front of the integrated nests and the nests with drinkers displayed more stationary behaviours than those in front of wall-placed nests or nests without drinkers.

There was no difference in the number of nest eggs but the integration of the nests inside the aviary led to a more even distribution of hens while nest searching. Placement of nipple drinkers in front of nests had no effect on the number of eggs laid in those nests.

Access platforms affect nest use by hens in aviaries

The same researchers in Switzerland compared nest use by hens when access to the nest was via perches or grids, explaining that access can affect nest acceptance by the birds and thereby prevent mislaid eggs.

They found that grid platforms rather than perches provide for improved nesting behaviour. Access via the perches resulted in more balancing, body contact and agonistic interactions as well as more mislaid eggs than when nest access was across the grid.

Pros and cons of providing perches during rearing and laying for caged layers

A major skeletal problem of conventionally caged hens is increased susceptibility to osteoporosis mainly due to lack of exercise, according to a group of researchers from Purdue University, Agricultural Research Service and Illinois State University. They explain that osteoporosis is a condition characterised by a progressive decrease in mineralised structural bone.

While attention has been paid to enriching laying cages, little research has been conducted on providing caged pullets with furnishings, in particular perches. So in their most recent study, they assessed whether metal perches during all or part of the life cycle of White Leghorns affected hen musculoskeletal health, especially at the end of lay (71 weeks of age).

They found that more muscle was present in the hens given access to perches as pullets, while bone mineralisation was higher in those birds with perch access as adults. However, the adult perch had the disadvantage of a higher incidence of keel bone deviations and keel fractures at end of lay.

Interestingly, in 2012, the same group published a paper on the effects of perch access on pullets during the rearing phase (5). Then, they concluded that perch access has beneficial effects on pullet health by stimulating leg muscle deposition and increasing the mineral content of certain bones without causing a concomitant decrease in bone mineral density.

The researchers published a paper earlier this year on the effects of perches in layer cages, concluding that enriching conventional cages with perches during the entire life cycle resulted in similar hen performance to the controls without perch access (6). Fewer broken back claws but poorer feed efficiency occurred because of prior experience with perches as pullets. Perch presence during egg laying improved back feather scores with more trimmed nails but caused more dirty eggs, broken back claws and poorer breast and tail feather scores.

Although perches allow chickens to express their natural perching instinct, it was not without causing welfare problems, they added.

Quantifying the effects of broiler housing advances

Modern broiler housing with better environmental-control capability is important for optimising weight gain, feed conversion and livability of broilers, according to recent research at the University of Arkansas.

In their study, the scientists present data on performance collected between 2004 and 2008 from a commercial four-house farm at the University’s Applied Broiler Research Farm. Pre-retrofit years were 2004 to 2005 and post-retrofit years were 2006 to 2008. They quantified performance improvements due to housing and equipment changes, including replacing curtain-sided with totally enclosed housing systems by measuring the difference between this farm and the industry live performance for corresponding years.

Broiler house age linked to food safety risk

Confirming the benefits of modern house design but from a different perspective, recent Danish research has revealed a link between the age of a broiler house and the occurrence of the foodborne pathogen, Campylobacter, in broiler flocks.

A study led by the Technical University of Denmark aimed to identify risk factors for the occurrence of Campylobacter by analysing data on the Campylobacter status for nearly 6,000 broiler flocks and 43 explanatory variables.

Among the factors found to be positively associated with the occurrence of Campylobacter in the broiler flocks was the age of the broiler house; the older houses carried a higher risk of a Campylobacter-positive flock. The researchers proposed that the association may be linked to the chimneys on older houses, which may be related to the increased presence of flies.

Cool perches for broilers

Novel research from Shandong Agricultural University in China shows that cool perches have positive effects on the performance and welfare of broilers. A study there investigated the interaction of stocking density and cool perch availability on broiler chickens raised at high ambient temperature (30.8°C or above).

High stocking density decreased the performance and welfare of the birds, while the availability of cool perching increased bodyweight gain and feed conversion efficiency, regardless of stocking density. The birds’ use of cool perches increased with age and decreased at higher stocking density.

The researchers observed that access to the cool perches changed behaviour patterns and reduced footpad or hock burns as well as damage to abdominal plumage.

Litter management to reduce ammonia levels

Controlling ammonia near watering lines to a level similar to other locations in the broiler house – such as near feeding lines and the house wall – could reduce ammonia generated by between 38 to 77 per cent. That is the conclusion of a study by the USDA Agricultural Research Service and Mississippi State University. They found that ammonia levels were correlated with the moisture levels in the litter.

Ammonia volatilised from broiler litter diminishes indoor air quality, which can potentially decrease bird productivity, the researchers said. Furthermore, ammonia emissions from broiler houses pose environmental concerns for ecosystem biodiversity, aquatic nutrient enrichment and particulate formation in the atmosphere.

After measuring ammonia level at various points in broiler houses during the growing cycle, they said that their findings support efforts for ammonia control, especially in the mid-period of grow-out, including zoned litter treatments near the drinker lines and particular attention to waterer management.

Choice of litter for hot and humid climates

Litter production, its physico-chemical properties and the nutrient composition of a range of locally available litter materials were compared with wood shavings as the control in an experiment at Eduardo Mondlane University in Mozambique.

The trial was carried out over 35 days in an open-sided and naturally-ventilated broiler house under conditions of high ambient temperatures and relative humidity.

Compared with wood shavings, more litter was produced using sand and corn cob and less with coconut husk, grass and newspaper. Rice hulls and corn cob litters were less compacted than the shavings. The water-holding capacity of sand and coconut husk was lower than shavings and that of grass was higher.

Floor types for ducks

Researchers based in Michigan and Iowa found very few differences between litter (in the form of pine shavings) and slatted flooring systems for Pekin ducks, in terms of performance or welfare and no differences in any of the environmental parameters measured within the barns. Daily weight gain was higher with the slatted floors. They examined birds from nine houses of each type on commercial farms in northern Indiana and southern Wisconsin.

The group concluded that there were no clear advantages for one particular flooring system over the other from the point of view of duck well-being and production.

Article courtesy of ThePoultrySite.com