Records on 983 cows born during a period of 10 yr (1966 to 1975) were used to estimate longevity and lifetime productivity of cows raised under range conditions. The cows were from a purebred Hereford and two multibreed synthetic groups, one composed of beef breeds (Beef Synthetic #1) and the other composed of two-thirds dairy breeds and one-third beef breeds (Dairy Synthetic). The cows were ra...

Charolais-sired calves from three groups of beef cows, similar in growth potential and mature size but different in genetic potential for milk production (5.6, 7.7, 9.0 kg/d; low, medium, and high, respectively), were allotted to two beef production systems each year for 3 yr. At weaning, calves in an intensive (Int) system went directly into the feedlot for finishing (236 d); calves in an exte...

Weaning is considered one of the most stressful periods in the beef production system for beef calves. During this process calves are subjected to a variety of stressors including removal from their mothers, new diets, processing (vaccination, dehorning, castration etc.), and possibly even new pen or pasture environments. These stressors, singly or in combination, can result in behavior or phys...

Selenium (Se) is an essential micronutrient in cattle, and Se-deficiency can affect morbidity and mortality. Calves may have greater Se requirements during periods of stress, such as during the transitional period between weaning and movement to a feedlot. Previously, we showed that feeding Se-fertilized forage increases whole-blood (WB) Se concentrations in mature beef cows. Our current object...

To prevent encephalomyelitis caused by Akabane virus, as observed in 2006, vaccination of calves is one of the most effective prophylactic measures. For vaccination of calves, the duration of the maternal antibodies need to be considered because these antibodies are an obstacle to the effectiveness of the vaccine. In order to estimate the age of antibody decay in calves and to find factors infl...

Plasma samples from suckling beef calves, transport-stressed weaned calves, 500 kg feedlot cattle, and lactating dairy cows were analyzed for vitamin C, folic acid, pantothenic acid, and vitamin B12' Plasma from stressed calves also was analyzed for vitamin B6' Differences in plasma levels were detected between groups. Plasma vitamin C was highest in suckling calves, but similar for stressed ca...

OBJECTIVE To compare calf weaning weight and associated economic variables for beef cows with serum antibodies against Mycobacterium avium subsp paratuberculosis (MAP) or from which MAP was isolated from feces with those for cows that were seronegative for antibodies against or culture negative for MAP. DESIGN Retrospective study. ANIMALS 4,842 beef cows from 3 herds enrolled in the USDA Na...

Soybean hulls (SBH) and soybean meal (SBM) were evaluated as potential supplements for preconditioning beef calves in Florida. Weaned calves were fed 4.76 lb/hd/d as fed of SBH or 1.40 lb/hd/d as fed of SBM for a 42-d preconditioning period. Calves fed SBH yielded higher preconditioning weight gains than calves supplemented with SBM (34.8 lb/ hd vs 22.3 lb/hd). An economic evaluation of precond...

To test adrenal responsiveness of beef cattle to stress, plasma norepinephrine, epinephrine, and cortisol responses of Angus x Hereford cattle to weaning were measured in blood samples taken from 1) eight cows and their 4- to 6-mo-old calves before and after separation and, the following day, before and after being reunited and 2) an equal number of control animals. After separation and before ...

OBJECTIVE The main objective of this study was to determine the effect of different diets for early-weaned (EW) calves on rumen development, and how this affects fat deposition in the longissimus dorsi of adult Korean Hanwoo beef cattle. METHODS Three EW groups were established (each n = 12) in which two- week-old Hanwoo calves were fed for ten weeks with milk replacer+concentrate (T1), milk ...