Journal Article

The ability of White Leghorn hens with trimmed comb and wattles to thermoregulate

D. S. AL-Ramamneh, M. M. Makagon and P. Y. Hester

in Poultry Science

Volume 95, issue 8, pages 1726-1735
Published in print August 2016 | ISSN: 0032-5791
Published online April 2016 | e-ISSN: 1525-3171 | DOI: https://dx.doi.org/10.3382/ps/pew110
The ability of White Leghorn hens with trimmed comb and wattles to thermoregulate

More Like This

Show all results sharing these subjects:

  • Zoology and Animal Sciences
  • Animal Pathology and Diseases
  • Animal Physiology
  • Ornithology
  • Veterinary Medicine

GO

Show Summary Details

Preview

It is estimated that each year over 19 million pullets in the United States have their combs partially trimmed at a young age to improve egg production and feed efficiency. A possible disadvantage of trimming is that the comb and wattles may be essential for thermoregulation during hot weather allowing for conductive cooling of the blood through vasodilation of superficial vessels in these integumentary tissues. The objective of this study was to investigate the effects of partial comb and wattle removal, performed at 21 d of age, on the ability of White Leghorns to thermoregulate before, during, and after an imposed heating episode that averaged 34.6°C for 50.5 h. An increase in mortality at 20 h and body temperature at 48 h post initiation of the heating episode demonstrated that hens with trimmed comb and wattles were not able to cope with heat stress as effectively as controls. The increase in wattle temperature in controls as compared to trimmed hens during the heating episode and following heat stress provides supportive evidence that blood pools to the peripheral surface for conductive heat loss. During high temperatures typical of summer, trimmed hens attempted to compensate for their lack of ability to transfer heat from their comb and wattles to the environment through increased proportion of panting and wing spreading. Under less extreme conditions with lowered ambient temperatures, the trimming of the comb and wattles did not impair the ability of hens to thermoregulate, as body temperatures and behavior were similar to controls with no mortality. Egg weight was the only production parameter adversely affected by the trimming of the comb and wattles as compared to controls. The implication is that hens need their combs and wattles to thermoregulate effectively during periods of high environmental temperature. Pullets should not be subjected to a comb and wattle trim if they are housed in laying facilities that are not appropriately cooled during the summer.

Keywords: comb trim; dubbing; wattle trim; hen; heat stress

Journal Article.  7055 words.  Illustrated.

Subjects: Zoology and Animal Sciences ; Animal Pathology and Diseases ; Animal Physiology ; Ornithology ; Veterinary Medicine

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content. subscribe or login to access all content.