Evaluation of F1 cows sired by Brahman, Boran, and Tuli bulls for reproductive, maternal, and cow longevity traits

This study evaluated reproductive, maternal performance, and longevity traits of 143 F-1 cows sired by Brahman (Br), Boran (Bo), or Tuli (T) bulls from Angus or Hereford cows from 1994 to 2011. Cow traits were measured at 7 yr of age in 1999 and 2000 for 1992- and 1993-born cows, respectively. From 2004 to 2010, excluding 2008, incisor condition (solid, broken, smooth) scores were assigned to cows remaining in production; scores were evaluated with two models. Broken and solid mouths were each assigned a score of "1" and smooth assigned "0"; Br-sired (0.76) and Bo-sired cows (0.71) had higher scores (P < 0.05) than T-sired cows (0.54). When solid mouths were scored 1 and smooth and broken scored 0, Br-sired cows (0.34) were higher than T-sired (0.01) (P < 0.05), and Bo-sired (0.23) cows were not different from either (P > 0.05). Age level of the cow within birth year was important for all modeled calf traits (P < 0.05). Birth weights were not different among cow inheritance (P > 0.05). Cow type influenced (P < 0.05) 205-d adjusted weaning weight of calves; Br-sired dams (228.1 +/- 2.37 kg) produced the greatest weaning weight, followed by Bo-sired (213.7 +/- 3.10 kg), and T-sired (201.6 +/- 2.69 kg) dams (P < 0.05). Adjusted means for calving rate for Bo-sired (0.92 +/- 0.02) cows were higher (P < 0.05) than Br-sired (0.86 +/- 0.02) and T-sired (0.86 +/- 0.02) cows. Adjusted mean weaning rate was greater (P < 0.05) for Bo-sired cows (0.86 +/- 0.02) than for cows sired by Br (0.77 +/- 0.02) bulls, but weaning rate for T-sired cows (0.80 +/- 0.02) were similar (P > 0.05). Cow weight was greater (P < 0.05) for Br-sired cows (590.5 +/- 8.35 kg) than for Bo-sired (505.8 +/- 10.46 kg) or T-sired cows (508.5 +/- 9.37 kg). BCS at weaning for 7-yr-old cows was similar (P = 0.08) for Br-sired and Bo-sired cows and lower for T-sired cows (P = 0.0005, condition scores 6.0, 6.3, and 5.8, respectively). Boran-sired cows were older when they were removed from the herd, on average (12.7 +/- 0.74 y, P = 0.03) than T-sired (10.6 +/- 0.61 y); Br-sired cow persistence was intermediate and not different (11.05 +/- 0.60 y, P > 0.06) from the others. Boran-sired cows had higher calving and weaning rates and better mouth scores than the other groups; consequently, they had greater longevity as well. Boran-sired and T-sired cows were moderate in size and weighed less than Br-sired cows throughout the study. Tuli-sired cows weaned the lightest calves and had the most tooth deterioration as they aged.