Effects of density and perch availability on the immune status of broilers
| Autor: | Inma Estevez, Estelle Russek-Cohen, Rosemary Pettit-Riley, R. A. Heckert |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Male
animal structures Lymphocyte Spatial Behavior Weight Gain Population density Leukocyte Count Immune system Animal science Bursa of Fabricius medicine Animals Animal Husbandry Population Density Perch Immune status biology General Medicine Organ Size biology.organism_classification Housing Animal medicine.anatomical_structure Antibody response Crowding Immunology Antibody Formation Animal Science and Zoology Female Flock medicine.symptom Weight gain Chickens Stress Psychological |
| Zdroj: | Poultry science. 81(4) |
| ISSN: | 0032-5791 |
| Popis: | This study attempted to evaluate the effect of various housing densities and perch availability on the immune status of commercial broilers. Birds were raised from hatch to 42 d of age with 10, 15, and 20 birds/m2 in pens, with and without the availability of horizontal perches. The immune parameters that were assessed were lymphoid organ weights, antibody response to SRBC in the last 10 d of growth, heterophil:lymphocyte ratios at 32 and 42 d of age, and lymphocyte blastogenesis of peripheral blood lymphocytes collected at 32 and 42 d of age. As density increased, bursa weight and bursa/body weight ratios decreased significantly (P < 0.05). Addition of perches to the pens also significantly decreased the bursa weights and bursa/body weight index (P < 0.01). No other significant effects were observed for the flock performance, morphometric data, or immunological tests between treatments. We concluded that under the conditions of this study, which tried to simulate commercial conditions, the bursal weight was the best indicator of stress that was related to housing density. Addition of perches appeared to increase this level of stress because the birds used the perches infrequently, and therefore there might have been a further reduction in the availability of floor space to the birds. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|