Effects of tylosin administration on C-reactive protein concentration and carriage of Salmonella enterica in pigs.

Objective: To evaluate the effects of tylosin on C-reactive protein concentration, carriage of Salmonella enterica, and antimicrobial resistance genes in commercial pigs.

Animals: 120 pigs on 2 commercial farms.

Procedures: A cohort of sixty 10-week-old pigs in 4 pens/farm (15 pigs/pen) was randomly selected.

Effect of delayed exposure of cattle to Mycobacterium avium subsp paratuberculosis on the development of subclinical and clinical Johne's disease.

Objective: To evaluate the effect of delayed exposure of dairy cattle to Mycobacterium avium subsp paratuberculosis (MAP) on the incidence of those cows testing positive for MAP and developing clinical Johne's disease (CJD).

Animals: 79 cows not exposed to MAP as calves (unexposed cohort) and 260 cows exposed to MAP as calves (exposed cohort).

Procedures: Cows in the unexposed cohort were born into 5 MAP-uninfected herds and introduced at various ages into 5 MAP-infected herds where the exposed cohort cows were born and raised.

Is an individual calving pen better than a group calving pen for preventing transmission of Mycobacterium avium subsp paratuberculosis in calves? Results from a field trial.

The objective of this study was to quantify the efficacy of using individual calving pens (ICP) from which manure was removed between successive calving compared with group calving pens (GCP) for limiting transmission of Mycobacterium avium subsp paratuberculosis (MAP) in Holstein calves. Every other pregnant cow in three Minnesota MAP endemic herds was assigned to calve in either the ICP or the GCP within 48-72 h prior to expected calving. Heifer calves born in the ICP were assigned to the intervention group (n=238) while heifer calves born in the GCP were considered controls (n=211).