Back to Search
Start Over
Effects of Outdoor Access and Indoor Stocking Density on Behaviour and Stress in Broilers in the Subhumid Tropics
- Source :
- Animals, Volume 9, Issue 12, Animals : an Open Access Journal from MDPI, Animals, Vol 9, Iss 12, p 1016 (2019)
- Publication Year :
- 2019
- Publisher :
- Multidisciplinary Digital Publishing Institute, 2019.
-
Abstract
- Studies investigating the welfare of commercial-line broiler chickens raised in houses with outdoor access in the tropics are scarce, and none have investigated whether responses vary according to indoor conditions. Hence, we assessed the effects of providing outdoor access at two indoor stocking densities on broiler chickens&rsquo<br />growth, behaviour, stress responses and immunity in a tropical region of Mexico. One hundred and sixty chickens were assigned to one of four treatments in a factorial design: with or without outdoor access and low or high stocking density indoors. Ad libitum sampling was used to build a purpose-designed ethogram. Scan sampling was used to record the number of birds engaged in each activity of this ethogram, both indoors and outdoors. Heterophil/lymphocyte (H/L) ratio and serum corticosterone levels were tested in weeks four and six of age. When the birds were 42 days old, they were slaughtered, and the bursa and spleen harvested and weighed. In an interaction between stocking density and outdoor access, birds at the high stocking density with no outdoor pens spent the least time walking and preening and more time lying (p &lt<br />0.05). Birds given outdoor access foraged more, but only at indoor low stocking densities (p &lt<br />0.05). Outdoor access reduced heterophil/lymphocyte ratio, indicating reduced stressor response. Birds with low stocking density indoors and outdoor access appeared more responsive to stressors, with elevated corticosterone and reduced spleen and bursa weights (p &lt<br />0.05). There were welfare benefits of outdoor access, principally in terms of increased activity, which were reflected in slower growth in the birds with outdoor access.
- Subjects :
- Serum corticosterone
040301 veterinary sciences
tropical regions
Biology
Article
0403 veterinary science
stress
Ethogram
Animal science
Stocking
heterophil-lymphocyte ratio
lcsh:Zoology
lcsh:QL1-991
lcsh:Veterinary medicine
General Veterinary
broilers
corticosterone
0402 animal and dairy science
Broiler
Tropics
stocking density
04 agricultural and veterinary sciences
040201 dairy & animal science
behaviour
welfare
lcsh:SF600-1100
Animal Science and Zoology
Scan sampling
outdoor access
Subjects
Details
- Language :
- English
- ISSN :
- 20762615
- Database :
- OpenAIRE
- Journal :
- Animals
- Accession number :
- edsair.doi.dedup.....b97caeb40e24764c4cfadca3b9687169
- Full Text :
- https://doi.org/10.3390/ani9121016