The effect of a progesterone/estradiol ear implant on the performance of young beef steers.
A progesterone/estradiol ear implant was tested over a 84 d feedlot period on 96 young Bonsmara steers which were randomly allocated to implant and control groups. Animals were adapted over 5 d to a complete feed formulated to South African feedlot standards. Health aberrations were observed and feed intake, mass gain and slaughter data were recorded. The implant group elicited a 23.2 kg gain per animal (P less than 0.01). Mean treatment feed intakes varied marginally but the implant group showed a 14.91% feed to gain improvement over controls. Warm carcass dressing percentage showed an overall improvement of 4.96% for both groups. Bloat incidence was calculated at 0.98% over 8,064 cattle feedlot days. Mortality was 2.08% and 12 animals were considered to be chronic bloaters. This may have been due to the high proportion of fine particles in the diet. A composite feed sample revealed that 62.48% consisted of particle lengths of 0.5-4mm. The effect of this on ruminal health is briefly discussed. It is concluded that the progesterone/estradiol implant provided greater mass gain and improved feed to gain ratios for treated steers over a control group.
Boyazoglu
P A
PA
Faculty of Veterinary Science, Medical University of Southern Africa, Medunsa.
Palmer
C
C
Campbell
M C
MC
Mankgeli
M R
MR
D000821:Animal Feed; D000818:Animals; D001835:Body Weight / Q000187:drug effects* / Q000502:physiology; D002417:Cattle / Q000502:physiology*; D004343:Drug Implants; D004423:Ear; D004958:Estradiol / Q000008:administration & dosage*; D011374:Progesterone / Q000008:administration & dosage*
D004343:Drug Implants; D011374:Progesterone; D004958:Estradiol