Effects of a tylosin tartrate pellet added to cattle growth implants on the incidence of implant site abscesses

Professional Animal Scientist, Sep 2002 by Zollers, W G Jr, Cook, D L, Janes, T H, Barton, W E

The steer groups and the heifer groups, described subsequently, completed separate consecutive trials using the same methods and facilities. Using the challenge model described previously, 126 English cross beef steers, approximately 1 yr of age and weighing 193 to 330 kg, were restrained in a typical hydraulic squeeze chute and induced to form an implant site abscess. These steers received 1) 120 mg trenbolone acetate and 24 mg estradiol (S-TBA/E2; Component(R) TE-S; Ivy Animal Health, Inc.) with (n = 22) or without (n = 24) a 29-mg tylosin tartrate pellet, 2) 140 mg trenbolone acetate (S-TBA; Component(R) T-S; Ivy Animal Health, Inc.) with (n = 24) or without (n = 16) a 29-mg tylosin tartrate pellet, or 3) 200 mg progesterone and 20 mg estradiol benzoate (S-P4/EB; Component E-S; Ivy Animal Health, Inc.) with (n = 24) or without (n = 16) a 29-mg tylosin tartrate pellet.

Eighty English cross beef heifers, approximately 1 yr of age and weighing 273 to 311 kg, were restrained in a typical hydraulic squeeze chute and induced to form an implant site abscess; the heifers received 1) 200 mg testosterone proprionate and 20 mg estradiol benzoate (H-T4/EB; Component(R) E-H; Ivy Animal Health, Inc.) with (n = 20) or without (n = 20) a 29-mg tylosin tartrate pellet or 2) 140 mg trenbolone acetate and 14 mg estradiol (H-TBA/E2; Ivy Animal Health, Inc.) with (n = 20) or without (n = 20) a 29-mg tylosin tartrate pellet.

One person implanted all animals in each trial. A separate Component(R) OneGun implanting device was designated for each treatment group. Study personnel were blinded as to the treatment code until the conclusion of each trial. Animals in each trial were housed together in one outdoor pipe and cable feedlot style pen. No shelter was provided from the elements. Implant sites were observed on d 6, 10, 16, 21, 28, and 35 following implantation (induction). Implant sites were scored as follows: 0 = no abscess present, 1 = abscess present, 2 = ruptured abscess (exudate present), and 3 = ruptured abscess (healed or scarred; implant missing).

The null hypothesis was that the addition of a tylosin tartrate pellet to the growth implant does not reduce the formation of implant site abscesses in steers and heifers. Fisher's Exact Test (SAS/STAT(R); SAS Institute Inc.; Cary, NC) was used to compare responses within each treatment group. The response of animals treated with an implant alone was compared with that of animals treated with an implant plus a tylosin tartrate pellet for each respective implant type (S-TBA/E2, S-TBA, SP4/EB, H-T4/EB, and H-TBA/E2). These were one-sided tests with a 0.05 alpha (1).

Results and Discussion

The abscess induction model was an effective test system to determine the ability of the tylosin tartrate pellet to prevent formation of an implant site abscess. When combining all implant site observations (n = 1,236), the induction model caused an abscess rate of 94.1% in animals that did not receive a tylosin tartrate pellet (542 abscesses observed in 576 observations). In animals receiving the tylosin tartrate pellet with the implant, the abscess rate was 4.2% (28 abscesses observed in 660 observations). Because the abscess induction model was developed using bacteria from spontaneously occurring implant site abscesses in feedlot cattle, it is likely that the Tylan(R) pellet efficacy will be repeatable under normal product use circumstances.