All beef cattle eat grass for at least the first half of their lives.
For gestation length the estimate was 0♴8. The beginning stage of life for both grass-finished and grain-finished cattle is the same for the first 8-10 months of the animal’s life. NOTE: Official ID is required for: dairy cattle of all ages, beef cattle 18 months of age and older. The heritability estimates ranged from 0♰1 to 0♰5 for calving difficulty and survival traits, from 0♱3 to 0♳3 for live weights and from 0♰6 to 0♱2 for pre-weaning live-weight gains. Click here for a list of other state animal health offices. There was no evidence of any major interaction between sire breed and location. Limousin-Holstein-Friesian crossbred cattle reached their peak carcass value at 800 days, although the difference between 365 and 800 days was just 80, making 12 months the most profitable age. As a group, the imported sire breeds had calves with 13-month weights 11♵ kg heavier than Hereford × Angus or 250kg heavier than straightbred Angus calves proportionally these advantages in weight were 005 and 011, respectively. Historically, heifers were first bred at 2 yr of age, but as beef. As a proportion of the mean for the Hereford × Angus crosses, there was a range due to sire breed of 0×17 for weaning weight and 013 for 13-month weight. The age to breed these heifers is an important decision for beef cattle producers. Sire breeds were ranked in approximately the same order for the weights of calves at weaning (5 months of age) and at 13 months of age.
The birth weights of calves by imported sire breds were greater than those of calves sired by local breeds by 4♷ kg. Birth weights by sire breed had a range of 7♲ kg, proportionally 0♲3 of the mean for the Hereford × Angus cross. The proportion of calves (from cows aged 3 years and over) experiencing birth difficulty averaged 8♶% and ranged from 17♷% for the Charolais, 15♱% for the Chianina and 13♷% for the Maine Anjou, to 2♳% for the Hereford and 0♹% for the Jersey. Overall, 92% of calves survived at birth and through to weaning, with a range from 86% for the Charolais sire breed to 96% for the Friesian and Jersey breeds. There were seven recently imported sire breeds, Blonde d'Aquitaine, Charolais, Chianina, Limousin, Maine Anjou, Simmental (including strains from four countries) and South Devon, and four local breeds, Angus, Friesian, Hereford and Jersey. The experiment was carried out over 5 years, generating a total of 4519 calves by 161 different sires. Eleven sire breeds were evaluated in New Zealand from the performance of their calves at two sites using Aberdeen-Angus cows, and at a third site using Angus and Hereford cows.