Early weaning in Northern Great Plains beef cattle production systems: III. Steer weaning, finishing and carcass characteristics

Abstract

a b s t r a c tStudies were conducted to evaluate the effect of early weaning steer calves on BW gain, feedlot performance, and carcass characteristics in two herds located in the Northern Great Plains, USA. Steer calves from predominantly Angus  Hereford dams were stratified within dam age and calving date (Fort Keogh Livestock and Range Research Laboratory (LARRL), Miles City, MT, USA; n¼354) and randomly assigned to one of three weaning treatments. In addition, steer calves from Angus and Angus  Simmental dams (n¼ 200; Judith Gap (JG), MT, USA) were stratified within breed group by age, calving date, and AI sire. Steer calves either remained with their dams until normal weaning (NW) at approximately 213-d of age or were early weaned at approximately 80-d of age onto one of two early weaning (EW) diets. Steer calves assigned to EW treatments received one of the following diets: (1) 17.5% CP (69% RDP and 7.53 MJ/kg NEm); or (2) 17.5% CP (57% RDP and 7.69 MJ/kg NEm). At time of normal weaning all LARRL steers were gathered and brought into pens at LARRL and held for 22 (2005) or 28-d (2006) before being sold to a commercial feedlot. Sire-identified steers from JG were sent to the University of Illinois for a finishing trial following a 28-d holding period. Steers that were EW were heavier (Po0.01) at time of normal weaning and entered the finishing phase in greater BW (Po0.01) than NW steers in both LARRL and JG studies. Age at harvest was similar for all LARRL steers (P¼ 0.79) regardless of weaning treatment whereas sire-identified JG steers that received EW treatment were harvested at a younger age (Po0.01) than NW steers. Sire-identified steers from JG that received EW treatments received better USDA quality grades (P¼0.05; upper 2/3 choice or better) than NW treated steers (Po0.01; lower 1/3 choice). Results from the present studies strongly support the concept that early-weaned steers reach maturity sooner during the finishing phase. However, if early-weaned steers are not identified prior to entrance into the feed yard and harvested at the same time as normal weaned calves of similar genetics and age, then earlyweaned steers may be subject to undesirable USDA yield grades (4 or greater).Published by Elsevier B.V.

Economics of early weaning in northern great plains beef cattle production system

“…At time of normal weaning, price ($US/45 kg) of steers were greater (P = 0.003; Table 1) for NW steer compared to EW steers. Thus, price differences were due to greater weaning BW for EW steers as found by [13]. However, precipitation was near normal average with good quality and quantity of forage as shown by [11]; which did not result in large differences in weaning BW.…”

“…A complete description of the materials and methods used were reported by [11][12][13]. Crossbred cows (predominantly Angus × Hereford) were stratified within cow age by calf sex and age, and then randomly assigned within strata to one of two weaning treatments at the start of breeding.…”

“…The economic analyses of weaning performance of the two calf weaning strategies were conducted using the data and results from [11][12][13]. In addition, the economic analysis evaluated performance based on market prices and weaning weights.…”

“…Weaning net income per calf was calculated using the feed and performance data measured by [11][12][13]. At time of normal weaning, price ($US/45 kg) of steers were greater (P = 0.003; Table 1) for NW steer compared to EW steers.…”

“…An evaluation of potential revenue from three 100-cow herds was conducted with a 2-yr partial budget (Table 3) of 3 weaning scenarios using the data and results from [11][12][13]. The 3 weaning scenarios were NW, EW, and the economic analysis of selling calves at EW (SEW) instead of developing them in a dry lot.…”