Post-Weaning Performance of Steers from Varying Calving and Weaning Strategies in Montana

Abstract

The impact of varied calving and weaning times on post-weaning production of steer calves was evaluated in a 3yr study. Steers (approximately 12 steers per calving-weaning treatment per year) born in late winter or early spring were weaned at 190 or 240 d of age, and steers born in late spring were weaned at 140 or 190 d of age after grazing with their dams on native range. Steers were pen-fed a growing diet until approximately 375 kg BW. They were then moved to an individual feeding facility and fed a higher-energy diet. Steers were allotted to harvest dates based upon visual estimates of degree of fat cover. Mixed model procedures were used to evaluate fixed effects of treatment and random effects of year and year × treat-which required greater number of days from weaning to harvest and produced carcasses with less marbling and lesser quality grades.

Effects of Calving Season on Stocker and Feedlot Performance

“…This experiment was conducted over a 3-yr period at the USDA-ARS Grazinglands Research Laboratory near El Reno, OK (35°32′ N 98°2′ W) and was a part of a larger study Month in which steers were shipped from Montana to Oklahoma. (Grings et al, 2005(Grings et al, , 2006. All procedures used in this portion of the experiment followed the recommendations of the Consortium (1988) and were approved by the USDA-ARS Grazinglands Research Laboratory Animal Care and Use Committee.…”

“…Each group had calves from each of the 6 calving season and weaning combinations. One group of calves stayed in Montana for growth, finishing, and harvesting; the effect of calving season and weaning age on performance was reported by Grings et al (2006). The remaining calves were housed in 1 of 3 outdoor pens (1,338 m 2 ) with one pen per calving season.…”

Evaluation of Beef Cattle Operations Utilizing Different Seasons of Calving, Weaning Strategies, Postweaning Management, and Retained Ownership

“…The original research was designed to allow cows to graze standing forage as much as possible within the constraints of weather and reproductive status. All inputs of supplemental feed were measured (Grings et al, 2005(Grings et al, , 2006. Feedstuffs were valued according to regional prices.…”

“…Feedstuffs were valued according to regional prices. Table 1 presents means for purchased feed costs for replacement heifers (Grings et al, 2006) averaged over the 3 yr of the study for each combination of calving season, weaning age, and heifer development. Nutritional management of mature cows varied only according to calving season (Grings et al, 2005).…”

“…The USDA-ARS conducted a large multi-regional experiment to evaluate the timing of calving in combination with several postweaning management or marketing scenarios (Grings et al, 2005(Grings et al, , 2006(Grings et al, , 2007Phillips et al, 2006). The objective of this study was to evaluate the economic performance of production or marketing systems studied in this project.…”