One hundred forty spring-born Angus x Gelbvieh and purebred Angus steers were selected for study as early weaned (EW; average age at weaning = 90 +/- 30 d) or traditionally weaned (TW; average age at weaning = 174 +/- 37 d) steers that were non-implanted or implanted (Synovex-S, Fort Dodge Animal Health, Overland Park, KS). Initially, steers were sorted by age, sire, and farm, and then allotted randomly in a 2 x 2 factorial arrangement of treatments of EW implanted (EWI), EW nonimplanted (EWN), TW implanted (TWI), or TW nonimplanted (TWN). Ultrasound measurements (US) of LM area (LMA), 12th rib fat thickness (US-BF), and marbling (US-M) were collected every 28 d during the time that steers were on feed. At 202 d of age, EW calves had larger US-LMA, US-BF, and BW than TW calves (37.9 vs. 32.3 cm2, 0.38 vs. 0.26 cm, and 271.6 vs. 218.9 kg, respectively; P < 0.001). At slaughter, EW calves had heavier HCW (290.4 vs. 279.7 kg, respectively; P < 0.05) and greater USDA marbling scores (51.25 vs. 46.26, respectively; P < 0.05) than TW calves; more EW steers graded USDA Choice or greater (P = 0.05). However, no differences were detected in BW (P = 0.15), LMA (P = 0.39), BF (P = 0.45), or liver abscess scores (P = 0.41). Twenty-four implanted steers were selected from the original group of 140 and sorted into two slaughter groups of 12. Twelve implanted steers from each weaning group, matched in slaughter BW but differing in age, were subsampled at slaughter to assess the effect of weaning age and chronological age on muscle tenderness. Younger animals had lower Warner-Bratzler shear force values (P < 0.001) than older calves after 14 d of postmortem aging; however, no differences were found in tenderness after 21 d of aging. Furthermore, there was greater variance (P < 0.001) in Warner-Bratzler shear force values among younger, EW steers vs. older, TW steers. These data provide evidence that early weaning of beef calves may be used as a tool to more effectively manage the cow-calf production system without compromising the quality of the offspring.

For the assumptions in the model, endemic N caninum infection decreases return to fixed assets for cow-calf herds. Of the potential control strategies evaluated, testing the entire herd for N caninum infection and excluding the daughters of seropositive dams as potential replacements provided the best economic return.)

We analyze the problem of asymmetric information between buyers and sellers in cattle auctions, using the problem of revaccinations as the point of departure. We present a simple model to show that if buyers do not know and cannot verify whether sellers have vaccinated their animals, then they may consider revaccination. Revaccination is only a part of the broader problem of information asymmetry that includes other quality issues and costs that can be saved, thereby affecting the welfare of both buyers and sellers. We consider structural characteristics of ranching, traditions, and consumers' preferences as well as proposals regarding third-party certification to argue that the problem of asymmetric information in cattle auctions is a persistent one. We also argue for a comprehensive empirical study of the incidence and impacts of buyer revaccination. Copyright 2007 International Association of Agricultural Economists.

Pigs infected with the zoonotic parasite Trichinella spiralis were detected on a farm in Maryland during an animal welfare investigation. Sera and/or tissues were collected from 49 pigs and three pig carcasses (7 weeks of age to adult, mixed sex). The tissues were tested for the presence of T. spiralis muscle larvae (ML) by tissue digestion, and the sera were tested for the presence of anti-Trichinella antibodies by ELISA. Seventeen of 50 (34%) pigs were infected with T. spiralis based on tissue digestion. Of these 17 pigs, sera were collected from 16; nine were serologically positive, three sera had OD values that were very close to the positive cut-off (0.30), but were still negative, and four were negative (suggesting that they had become infected within a few weeks of testing). All pigs that tested negative by tissue digestion for ML were also ELISA negative. The farm was subsequently depopulated of pigs. Six months later, testing of trapped scavenging mammals in the farm environment demonstrated that 41% were infected with T. spiralis. After 12 months, 10% of trapped animals were T. spiralis positive, and after 18 months, T. spiralis could not be detected in the scavenging mammal population surrounding the farm. Results of the study suggest that T. spiralis, typically transmitted in the peridomestic rat-pig-human cycle in the US, was not maintained in scavenging mammals in the absence of infected pigs.

The paper analyzes the problem of asymmetric information between buyers and sellers in cattle auctions. An illustration is made regarding the vaccinations that the animals receive. Buyers do not know and cannot verify if sellers have vaccinated their animals forcing them to consider revaccination. Revaccination is only a part of the broader problem of information asymmetry that includes other quality issues and costs that can be saved, thereby increasing the welfare of both buyers and sellers. Structural characteristics of ranching, traditions and consumers' preferences are taken into account and a wider approach is attempted to explain the persistence of the problem in light of potential institutional solutions. We argue for a comprehensive empirical study of the incidence and impacts of buyer revaccination.