Submitted to: American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/2008
Publication Date: 8/16/2009
Citation: Gunter, S.A., Jaeger, J.R., Beck, P.A. 2009. The effect of high-starch diets fed to beef cows during late gestation on the feedlot performance and carcass characteristics of offspring. Journal Animal Science. 87(E-Suppl. 3):29. (Abstract)
Technical Abstract: The fetus requires glucose as an energy source; hence, it was hypothesized that diets rich in glycogenic substrates during late gestation would yield offspring that have a greater potential to produce a high quality carcass. In November of 2005 and 2006, 54 and 59, respectively, non-lactating cows of mostly Angus breeding were stratified by body condition score, parity, body weight (BW), and distributed randomly into four 0.81-ha drylots (Hope, AR); the cows were bred to calve in February. Cows in 2 pens were program fed a high-concentrate diet (67.8% hominy, 12.1% chopped corn stalks, 1.5% cottonseed meal, 2.3% minerals, and 15.9% water as fed; 79% DM, 13% CP, 2.1 megacalories of net energy of maintenance (NEm)/kg [DM basis]) the last 84 d of gestation meeting requirements for NEm. Cows in the other drylots were fed bermudagrass hay (9% CP, 1.1 megacalories of NEm/kg [DM basis]) plus a hominy-based supplement. In both years after wintering, pairs grazed a bermudagrass pasture and calves were weaned in September, calves grazed on winter-annual pasture until mid-March, then were shipped to a feedlot (Hays, KS) and finished on a high-concentrate diet (195 or 200 d, respectively). Beginning (254 vs. 245 kg), mid (132 d on feed; 442 vs. 436 kg), and ending (517 vs. 513 kg) BW did not differ (P equal or greater than 0.25) between calves from hay and program fed cows, respectively. Feedlot average daily gain (kg), daily dry matter intake (kg), and BW gain:feed did not differ (P equal or greater than 0.51) between calves from hay (1.36, 10.7, 0.125) and program (1.33, 11.0, 0.123) fed cows. Hot carcass weight (318 vs. 321 kg), yield grade (2.3 vs. 2.4), USDA marbling score (407 vs. 394), LM area (79.4 vs. 80.0 cm2), and fat cover over the 12th rib (1.14 vs. 1.14 cm) did not differ (P equal or greater than 0.52) for calves from hay and program fed cows, respectively. These results indicate that supplying additional glycogenic substrates to cows the last 84 d of gestation did not seem to augment carcass quality of offspring after finishing compared to cows fed hay plus a supplement.