Stable fly, Stomoxys calcitrans, mouthpart removal influences stress and anticipatory responses in mice.

Biting fly attack induces a variety of stress and anxiety related changes in the physiology and behaviour of the target animals. Significant reductions in pain, or more appropriately, nociceptive sensitivity (latency of a foot-lifting response to an aversive thermal stimulus), are evident in laboratory mice after a 1 h exposure to stable flies, Stomoxys calcitrans. The role of the various components of biting fly attack in the development of this stress-induced reduction in pain sensitivity (analgesia) is, however, unclear.

Scrotal/testicular thermoregulation and the effects of increased testicular temperature in the bull.

Scrotal/testicular thermoregulation is a complex process controlled by numerous local mechanisms that attempt to maintain the testes at conditions ideal for spermatogenesis. This article provides a background of the anatomy and physiology of the bovine scrotum and its contents with emphasis on thermoregulation. Experiments are cited that demonstrate scrotal/testicular thermoregulation mechanisms and the effect that changes in ambient temperature have on internal testicular temperature and subsequent seminal quality.

An endoglucanase from the anaerobic fungus Orpinomyces joyonii: characterization of the gene and its product.

An endoglucanase gene (celA) was isolated from a genomic library of the ruminal fungus Orpinomyces joyonii. DNA sequence analysis of celA revealed an intronless gene encoding a typical signal sequence, an N-terminal catalytic domain, two repeated regions linked by a short Ser/Thr-rich linker and a domain of unknown function. The deduced amino acid sequence of the catalytic domain showed homology with the family 5 cellulases.

The rumen: a unique source of enzymes for enhancing livestock production.

Increasing competition in the livestock industry has forced producers to cut costs by adopting new technologies aimed at increasing production efficiency. One particularly promising technology is feeding enzymes as supplements for animal diets. Supplementation of diets for non-ruminants (e.

Systemic clearance and demethylation of caffeine in sheep and cattle.

Pharmacokinetics of caffeine have been studied in sheep and cattle treated with caffeine (5 mg/kg) by intravenous injection. Terminal-phase elimination half-lives were 8.9 hr in sheep and 8.

Insulating the scrotal neck affects semen quality and scrotal/testicular temperatures in the bull.

Nine Simmental X Angus bulls (2-yr of age) were used in 2 experiments. In Experiment 1, the scrotal neck was insulated (from Day 1 to Day 8) in 5 bulls, and semen was collected from all 9 bulls by electroejaculation approximately every 3 d until Day 35. Bulls with insulated scrotal necks had lower percentages of normal spermatozoa (P < 0.