Abstract

In order to determine if including flaxseed in creep feed would affect nursing calf performance, subsequent feedlot performance, and ensuing carcass composition, ninety-six cow-calf (steer) pairs (663 ± 9 kg initial cow BW; 168 ± 1 kg initial calf BW) from the Central Grasslands Research Extension Center, Streeter, ND (located in south-central North Dakota) were stratified by cow age and steer weight, and allotted to one of 12 native pastures (8 pairs per pasture). Pastures were assigned randomly to one of four treatments (DM basis): 1) no creep feed (CON); 2) 0% flaxseed creep feed which was 55% wheat middlings, 39.5% soy hulls, 4.2% molasses, and 1.3% limestone (CRP); 3) low flaxseed creep feed which was 12.5% flaxseed, 26.0% wheat middlings, 56.0% soy hulls, 4.2% molasses, and 1.3% limestone (LOW); or 4) high flaxseed creep feed which was 25.0% flaxseed, 69.5% soy hulls, 4.2% molasses, and 1.3% dicalcium phosphate (HIGH). All creep fed calves were offered CRP ad libitum for the initial 21 d to acclimate calves to feeders and diets. Treatment diets were offered ad libitum for 37 d prior to weaning. Calves were then co-mingled and fed a corn and corn-silage-based backgrounding diet for 98 d after which they were fed a corn-based finishing diet for 143 d. Once cattle were appraised to have an average of 1 cm of external fat, cattle were transported to an abattoir, harvested, chilled for 24 h, and carcass data were collected. Loin samples (longissimus lumborum; approx. 1000 g) were removed from the left side of each carcass, transported to the South Dakota State University meat laboratory, vacuum packaged and aged at 4° C for 14 d after which 2.54-cm-thick steaks were cooked and Warner-Bratzler shear force was measured. There was no difference in creep feed intake between control and flaxseed creep feeds (P = 0.26) or due to flaxseed level (P = 0.14). Creep-fed calves had greater pre-weaning ADG (P = 0.05) than CON calves. Backgrounding ADG was not affected (P = 0.34) by creep feed; however, creep-fed calves tended (P = 0.11) to have greater finishing ADG. Flaxseed addition had no effect on backgrounding ADG (P = 0.36) or finishing ADG (P = 0.71) compared to CRP-fed calves. Creep-fed calves had greater HCW (P = 0.05) and lower marbling scores (P = 0.08) than CON. Calves fed flaxseed had lower marbling scores (P = 0.06) than those fed CRP; however, calves fed HIGH had greater marbling scores (P = 0.08) than those fed LOW. Including flaxseed in nursing steer creep feed for the last 37 d prior to weaning did not affect nursing calf or post-weaning performance, but may decrease marbling scores.