|Dozier Iii, William|
Submitted to: Southern Poultry Science Society Meeting Abstracts
Publication Type: Proceedings
Publication Acceptance Date: 10/30/2005
Publication Date: 1/15/2005
Citation: Dozier III, W.A., Lott, B., Branton, S.L. 2005. Effects of two diverse air velocities at high temperatures with a high dew point on broiler performance. Southern Poultry Science Society Meeting. Abstract 208. p. 49.
Technical Abstract: Tunnel ventilation is a common practice in broiler production to remove excess heat. Previous research from this laboratory has shown that applying air velocity of 180 m/min improved growth responses of broilers from 42 to 49 d of age. Information is sparse on the ventilation needs of broilers reared under cyclic high temperatures. This study examined the responses of broilers to increasing air velocity from 120 to 180 m/min exposed to cyclic temperatures of 25-35-25o C and a dewpoint of 23oC from 21 to 49 d of age. Three trials were conducted. In each trial, seven-hundred and forty-two male broilers were randomly assigned to either six floor pens (53 birds/pen; 0.07 m2/bird) or two air velocity tunnels at 21 d of age. Each tunnel contained four pens (53 birds/pen; 0.07 m2/bird). Three treatments were employed: 1) control (still air), 2) air velocity of 120 m/min, and 3) air velocity of 180 m/min. Each of three trials over time represented a block. The experimental unit was the average value of the four pens in a wind tunnel and six floor pens, respectively, since air velocity treatments were fixed effects. Subjecting broilers to an air velocity of 180 m/min increased (P'0.05) BW and BW gain compared with broilers exposed to an air velocity of 120 m/min from 29 to 35, 36 to 42, 43 to 49, and 21 to 49 d of age. Broilers reared with an air velocity of 180 m/min consumed more (P'0.02) feed from 36 to 42 and 21 to 49 d of age, had improved (P' 0.01) feed conversion from 21 to 49 d of age, and reduced (P'0.03) the incidence of mortality from 36 to 42 d of age compared with birds subjected to air velocity of 120 m/min. Subjecting birds to air velocity increased (P'0.02) BW, BW gain, and feed consumption during each weekly interval from 21 to 49 d of age over the control group. These data indicate that applying air velocity of 180 m/min is advantageous with high cyclic temperatures for broilers having an approximate BW of 2.0 to 3.0 kg.