Bvcfx

University of Nebraska - Lincoln

DigitalCommons@University of Nebraska - Lincoln
Nebraska Beef Cattle Reports Animal Science Department

1-1-2008

The Effect of Delaying Initial Feedlot Implant on Performance and Carcass Characteristics of Calffed Steers
William A. Griffin
University of Nebraska - Lincoln

Don C. Adams
University of Nebraska - Lincoln, dadams1@unl.edu

Richard N.Funston
University of Nebraska - Lincoln, rfunston2@unl.edu

Griffin, William A.; Adams, Don C.; and Funston, Richard N., "The Effect of Delaying Initial Feedlot Implant on Performance and Carcass Characteristics of Calf-fed Steers" (2008). Nebraska Beef Cattle Reports. Paper 33. http://digitalcommons.unl.edu/animalscinbcr/33

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The Effect of Delaying Initial Feedlot Implant on Performance and Carcass Characteristics of Calf-fed Steers
William A. Griffin Don C. Adams Rick N. Funston1 ProcedureExperiment 1 One hundred steer calves (474 + 44 lb) were received each year for two consecutive years from the Gudmundsen Sandhills Laboratory in the fall. Upon arrival, cattle were dewormed and vaccinated using standard feedlot procedures. Steers were not given an implant at branding. Therefore, the initial feedlot implant would have been the first implant in the life of the calf. Upon arrival,calves were weighed and allotted to one of two treatments: delay initial feedlot implant until 0 days on feed or receive initial feedlot implant at the beginning of the finishing period. Weights were taken on day 0, 0 (delay implant), 115 (reimplant), and 212. Calves in both treatments were reimplanted on the same day. Experiment 2 One hundred twenty-seven and eighty-four steer calves (525 + 52 lb)were received in year one and year two, respectively. Calves were received from the Gudmundsen Sandhills Laboratory in the fall. Upon arrival, cattle were dewormed and vaccinated using standard feedlot procedures. Steers received for this experiment were given a Synovex C implant at branding. Upon arrival calves were weighed and allotted to one of two treatments: delay initial feedlot implantuntil 0 days on feed or receive initial feedlot implant at the beginning of the finishing period. Weights were taken on day 0, 0 (delay implant), 104 (reimplant), and 218. Calves in both treatments were reimplanted on the same day. In both experiments, weights were the average of two consecutive day weights taken in the morning prior to feeding. Final BW was calculated by adjusting hot carcassweight to a common 6% dressing percentage. Cattle were slaughtered at a commercial packing plant and hot carcass weight was collected on day of slaughter. Following a 24-hour chill USDA Marbling Score, KPH fat, fat thickness, and ribeye area data were collected. Yield grade was calculated for analysis. Additionally, cattle in both experiments were given Synovex S® as their initial feedlot implant andreimplanted with Synovex Choice®. All calves were fed a diet containing 48% dry-rolled corn, 40% wet corn gluten feed, 7% alfalfa hay, and 5% supplement. Statistical analysis was performed using the Mixed procedure of SAS, with pen as the experimental unit, and treatment, year, and year by treatment interaction in the model statement. Results Experiment 1 The simple effects of treatment by yearfrom Experiment 1 are presented in Table 1. For feedlot performance there was no treatment by year interaction (P > 0.20). When looking at implant treatment, initial BW (P = 0.60), BW at reimplant (P = 0.16), and final BW (P = 0.52) were not different. However, BW on day 0 was 24 lb greater for steers in the normal implant treatment (P < 0.01). Daily gain from day 0 to 115 (P = 0.5), day 0 to...