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• A targeted selective treatment (TST) scheme was evaluated in hair sheep under hot-humid tropical conditions.

Concern has been expressed on animal welfare in the use of electro-ejaculation (EE) as a semen collection technique. Furthermore, even though breed differences in stress response have been demonstrated in goats, a lack of background information characterizes the Criollo genotype. Therefore, in the present experiment, changes in concentrations of serum cortisol in serial blood samples were used to quantify stress response to EE in Criollo goats. Twenty intact Criollo bucks aged 1.5–3 years and weighing between 33 and 40 kg were randomly assigned to one of two treatments: bucks that were electro-ejaculated (T1) compared to males that a rectal probe was inserted without EE (T0). Blood samples were collected by venipuncture at 0 (immediately before inserting the rectal probe), 20, 40, 60 and 90 min after the onset of the experiment. To compare blood cortisol concentrations between treatments and the sequential data recorded on the same set of animals, a repeated measures analysis of variance model was used. The increases in concentrations of serum cortisol were significantly higher ( P 350% increase in serum cortisol concentration 20 min after EE indicates an acute stress response despite the peak values being only slightly above the basal serum cortisol levels found in other goat breeds.

A survey was conducted between June and September 2000 in order to detect antibodies against caprine arthritis-encephalitis virus (CAEV) in 83 goat herds in the state of Yucatan, Mexico. A total of 1078 goats older than 4 months of age (mostly of Criollo breed) were sampled in the survey. An agarose gel immunodiffusion (AGID) test showed that three herds (3.6%) were seropositive to CAEV. In those herds a total of four animals sampled were seropositive (0.4%). All of the seropositive goats were imported to the Yucatan either from the neighboring Mexican state of Campeche or the United States of America (USA). These results highlight the need for implementation of control policies in Yucatan and careful monitoring of this goat population in order to ensure a continued low seroprevalence of CAEV. Policies of “rural development” and “genetic improvement” through animal imports, either governmental or private, must take into account the possibility of causing an increase in seroprevalence of CAEV in Yucatan.