Cunningham, Samantha Fern (2005-08). Evaluation of F1 cows sired by Brahman, Boran, and Tuli for reproductive and maternal performance and cow longevity. Master's Thesis.
Thesis
Birth (BW) (n = 1,107) and weaning weight (WW) (n = 1,024), pregnancy rate (PR) (n = 1,255), calf crop born (CCB) (n = 1,232), calf crop weaned (CCW) (n = 1,225), and cow??s weight at palpation (CW) (n = 1,403) were evaluated from 1994 to 2004 in 143 F1 females who were sired by Brahman (B), Boran (Bo), and Tuli (T) bulls and who were out of Angus and Hereford cows. In 2004, mouth scores (MS) (n = 71) were assigned to the remaining females. PR, CCB, CCW, CW, and BCS were evaluated using a model that consisted of sire of dam breed, dam of dam breed, and calf??s birth year/age of dam as fixed effects. Sire of dam within sire breed of dam and dam within sire of dam within sire breed of dam were used as random effects. BW and WW were analyzed using the same model including calf??s gender. Two-way interactions were tested for significance. Year/age was significant for all traits (P < 0.05). Adjusted means for BW for calves out of cows by B, Bo, and T sires were 35.66, 35.38, and 35.59 kg respectively, and were not different (P > 0.05). Adjusted means for WW for calves out of cows by B, Bo, and T sires were 233.4, 220.1, and 208.2 kg respectively, and were significantly different. For both BW and WW, male calves were heavier (P < 0.05) than females. Adjusted means for PR for females sired by B, Bo, and T bulls were 0.914, 0.945, and 0.920, and were not different (P > 0.05). Adjusted means for CCB for females sired by B, Bo, and T bulls were 0.890, 0.943, and 0.910 respectfully, and Bo was higher (P < 0.05) than B. CCW showed the same ranking as CCB with adjusted means of 0.834, 0.887, and 0.857 for cows by B, Bo, and T bulls, with Bo being higher (P < 0.05) than B. CW adjusted means, in the fall of 2002, were 594.29, 519.38, and 517.3 kg. B-sired females were heavier (P < 0.05) than Bo- or T- sired cows. More Bo- (P = 0.013) and B-sired (P = 0.003) cows had solid mouths in 2004 than T-sired cows.
Birth (BW) (n = 1,107) and weaning weight (WW) (n = 1,024), pregnancy rate (PR) (n = 1,255), calf crop born (CCB) (n = 1,232), calf crop weaned (CCW) (n = 1,225), and cow??s weight at palpation (CW) (n = 1,403) were evaluated from 1994 to 2004 in 143 F1 females who were sired by Brahman (B), Boran (Bo), and Tuli (T) bulls and who were out of Angus and Hereford cows. In 2004, mouth scores (MS) (n = 71) were assigned to the remaining females. PR, CCB, CCW, CW, and BCS were evaluated using a model that consisted of sire of dam breed, dam of dam breed, and calf??s birth year/age of dam as fixed effects. Sire of dam within sire breed of dam and dam within sire of dam within sire breed of dam were used as random effects. BW and WW were analyzed using the same model including calf??s gender. Two-way interactions were tested for significance. Year/age was significant for all traits (P < 0.05). Adjusted means for BW for calves out of cows by B, Bo, and T sires were 35.66, 35.38, and 35.59 kg respectively, and were not different (P > 0.05). Adjusted means for WW for calves out of cows by B, Bo, and T sires were 233.4, 220.1, and 208.2 kg respectively, and were significantly different. For both BW and WW, male calves were heavier (P < 0.05) than females. Adjusted means for PR for females sired by B, Bo, and T bulls were 0.914, 0.945, and 0.920, and were not different (P > 0.05). Adjusted means for CCB for females sired by B, Bo, and T bulls were 0.890, 0.943, and 0.910 respectfully, and Bo was higher (P < 0.05) than B. CCW showed the same ranking as CCB with adjusted means of 0.834, 0.887, and 0.857 for cows by B, Bo, and T bulls, with Bo being higher (P < 0.05) than B. CW adjusted means, in the fall of 2002, were 594.29, 519.38, and 517.3 kg. B-sired females were heavier (P < 0.05) than Bo- or T- sired cows. More Bo- (P = 0.013) and B-sired (P = 0.003) cows had solid mouths in 2004 than T-sired cows.
