320 Effect of Breed of Sire and Calving Season on Feedlot Performance and Carcass Characteristics. (21st September 2022)

• Record Type: Journal Article
• Authors: Moore, Mikayla F; Briggs, Emma A; Wilson, Blake K; Reuter, Ryan R; Beck, Paul A; Foote, Andrew P; Lalman, David
• Is Part Of: Journal of animal science. Volume 100(2022)Supplement 3
• Page Start: 153
• Page End: 154
• Publication Date: 2022-09-21
• Subjects: beef cattle -- calving season system -- feedlot nutrition; Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.1093/jas/skac247.285
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: Four years of feedlot performance and carcass characteristics were pooled on spring-(SPRING) and fall-(FALL) born steers (n=460) into a mixed model to evaluate the effects of calving season, sire breed (Angus [AN], Charolais [CHAR] or Hereford [HER]) and their interaction on feedlot performance and carcass traits. Initial and final BW, DOF, ADG, DMI, and G:F were evaluated as performance measures and HCW, YG, FT, REA, and MS were collected at harvest. There was no season by breed interaction for entry or final BW (P >0.05). SPRING steers (400.2 kg, 686.4 kg) weighed more than FALL (350.9 kg, 668.3 kg) upon entering and leaving the feedyard (P< 0.001). CHAR weighed 14.3 kg less than AN upon feedlot entry (P=0.01) although final BW did not differ by breed (P >0.05). SPRING steers (21.8 kg/d) consumed more feed than FALL steers (18.8 kg/d; P=0.002), but there was no difference in gain:feed due to calving season nor sire breed (P≥0.575). A calving season by sire breed interaction was present for ADG and DOF (P≤0.014). FALL AN (1.70 kg/d) and FALL HER (1.80 kg/d) gained more than FALL CHAR (1.55 kg/d;P< 0.001) and FALL AN were fed over a shorter period than FALL CHAR and FALL HER (P≤0.006). However, average daily gain of SPRING calves did not differ by breed (P >0.05). There was a tendency for FALL (400.9 kg) steers to have lighter carcasses than SPRING steers (407.9 kg; P=0.068). HER carcasses were 18.0 kg heavier than AN carcasses (P< 0.001), but did not differ from CHAR (P=0.13). CHAR had larger REA (93.5 cm 2 ) than both AN (87.7 cm 2 ) and HER steers (88.5 cm 2 ;P≤0.001). Fall-born steers had less YG than spring-born steers (P< 0.042). Feedlot performance was generally less for fall-born steers finished during the winter months. Under these conditions, numerous performance and carcass traits were influenced by the interaction of breed and season.