Visual Tags Research Articles

Traceability in cattle and small ruminants in Canada.

Traceback systems for cattle and small ruminants are of international concern after the outbreaks of bovine spongiform encephalopathy in the European Union and foot and mouth disease in the United Kingdom and South America. Implementation of a national or international identification system depends on meeting a balance between cost, reliability/durability, ease of use, data transfer speed, protection from fraud, avoidance of entry into the food chain and animal welfare issues. As of 1 January 2001, Canada has instituted a national identification programme for cattle, which will have annual operating and administrative costs of Can$0.20 per head, excluding ear tags. The system will provide herd of origin traceback and individual animal identification by ear tags for all beef cattle. A number of identification technologies are available that would have advantages over visual tags, but these are currently too costly without government support (electronic identification, deoxyribonucleic acid [DNA] fingerprinting), too slow (DNA fingerprinting) or have not been tested sufficiently (retinal imaging) to warrant mandatory inclusion in a national traceback/identification system.

An Evaluation of Soft Visual Implant Tag Retention Compared with Anchor Tag Retention in Channel Catfish

Abstract Channel catfish Ictalurus punctatus (280–379 mm, total length) were tagged with soft visual implant alphanumeric tags and Floy t-bar anchor tags to evaluate long-term tag retention (270 d). Visual implant tags were not considered to be a viable method of tagging channel catfish; tag loss was 100% at 172 d after tagging. Retention of anchor tags was 100% at 97 d; however, tag retention had decreased to 71% at 270 d after tagging.

A Visual Tagging Process for Mix and Sort Combinatorial Chemistry.

Colored glass beads and caps provide a simple color-coding strategy adapted to porous plastic containers and allow visual identification of the individual constituents of combinatorial libraries.

Comparison of electronic and visual identification systems in pigs

Internal and external electronic identification devices (EID) were compared with visual ear tags in a series of trials in pigs. In sows (244 animals), external EID tags and visual tags performed comparatively well with loss rates of 1.6% and 3.7%, respectively, over—on average—338 days (SD=168 days). External EID failure rate was 0.4%. In two other trials, 180 piglets were tagged at weaning with external EID, visual tags and implantable EID (type A: 23 mm; type B: 11.5 mm). A location at the right ear base was used for implantation. Only minor migration of <1 cm occurred. A total of 3.3% of pigs showed signs of infection at the implantation site (all with type A). The loss rate of type A and type B transponders within 4 weeks after implantation was 18.1% and 0%, respectively. Loss rates before slaughter for the different identification systems were: EID ear tags 0%, visual ear tags 1.7%, implant A 19.4%, implant B 0%. At slaughter, 23.4% of the EID ear tags were either lost or damaged. Remaining technical problems related to practical use of EID systems will have to be removed before their value can be fully realised within the pig industry.

Cues Used by European Starlings for Detecting Methiocarb-Treated Grapes

Experiments were conducted to determine the types of cues European starlings (Sturnus vul- garis) used to detect methiocarb-treated grapes and to determine whether the use of visual tags would enhance repellency to this chemical. One untreated and one treated grape bunch were offered to individ- ually caged birds during a series of 2-hour feeding trials, with the position of the treated bunch either variable or stationary during successive trials. Starlings relied on locational cues for identifying methiocarb- treated bunches and showed avoidance of untreated grapes later placed on the same side of the cage. Visual tags (3.8-cm2 pieces of yellow cloth tape with a brown X on each side) did not hasten the recognition of locations where methiocarb-treated bunches were placed, nor did they enhance the subsequent repellency. Methiocarb failed to inhibit overall consumption of grapes. Abstract: Experiments were conducted to determine the types of cues European starlings (Sturnus vul- garis) used to detect methiocarb-treated grapes and to determine whether the use of visual tags would enhance repellency to this chemical. One untreated and one treated grape bunch were offered to individ- ually caged birds during a series of 2-hour feeding trials, with the position of the treated bunch either variable or stationary during successive trials. Starlings relied on locational cues for identifying methiocarb- treated bunches and showed avoidance of untreated grapes later placed on the same side of the cage. Visual tags (3.8-cm2 pieces of yellow cloth tape with a brown X on each side) did not hasten the recognition of locations where methiocarb-treated bunches were placed, nor did they enhance the subsequent repellency. Methiocarb failed to inhibit overall consumption of grapes.

Cues used by house finches for detecting methiocarb-treated grapes

Laboratory tests were conducted to determine how house finches ( Carpodacus mexicanus) detect and avoid bunches of grapes treated with the repellent methiocarb and to determine whether the presence of a visual tag paired with methiocarb-treated bunches facilitates this detection and avoidance. Individually caged birds were offered one untreated and one treated grape bunch during a series of 2 h preference feeding trials, and each bird's total consumption and its preference for the treated bunch were measured. When the positions of the treated and untreated bunches were alternated during successive feeding trials, house finches took just as much from the methiocarb-treated bunch as from the untreated bunch, but their total consumption declined. When the positions of the treated and untreated bunches were kept constant, total consumption initially declined but increased again to pretreatment levels as the birds learned to feed from the non-treated bunch. Consumption from the grape bunch on the side of the cage where the birds had previously encountered the repellent remained low even after methiocarb treatments ended. The visual tag had little effect on either total consumption or grape bunch preference. The implications of these findings for controlling bird damage to ripening grapes are discussed.