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Biomedical subjects

W J Goodger

Publications and source records attributed to W J Goodger.

32 records · Page 2Linked to original sources
PubMed1987

The economic benefit of treating subclinical Streptococcus agalactiae mastitis in lactating cows.

The economic benefits of treating lactating cows for Streptococcus agalactiae mastitis were studied at a large (689 milking cows) central California dairy. Postcure milk production of case cows (infected, treated, and cured) was compared with production of paired control cows (uninfected) and was matched for yield, days in milk, days in gestation, and parity. A simulation was used to plot expected lactation curves for mastitic cows (infected, not treated) with characteristics similar to those of each control cow, and these curves were compared with actual case-cow lactation curves. The difference in actual and expected production was used to calculate net economic benefits of treatment. Comparison of expected with actual production indicated a net benefit from treatment of $396/cow for cows treated in early lactation and $237 for cows treated in midlactation, but a net loss of $55 for cows treated in late lactation. Lactation number did not have a significant impact on economic benefits of treatment. In contrast to other studies indicating no economic benefit from treating mastitis during lactation, this study's positive results may have been attributable to the high cure rate (98%) and the subclinical form of mastitis being treated. Streptococcus agalactiae mastitis treatment during early and midlactation would appear to be an economically justifiable option for dairy managers.

Animals↗
PubMed1987

Benefits and costs of a control program for an epizootic of Staphylococcus aureus mastitis.

In response to an epizootic of Staphylococcus aureus mastitis, the owner of a 2,000-cow dairy instituted a treatment, prevention, and control program (hereafter, "intervention program") consisting of teat dipping, bacteriologic culturing of milk from all fresh cows and from cows with clinical signs of infection, and culling cows found to be infected. The program was highly beneficial, yielding $2.40 in direct benefits for every $1 invested.

Animals↗
PubMed1987

An epidemiologic study of mortality in veal calves subsequent to an episode of zinc toxicosis on a California veal calf operation using zinc sulfate-supplemented milk replacer.

Ninety-five 3- to 6-month old male Holstein veal calves were evaluated after an episode of zinc toxicosis, to describe clinical signs and to identify management and/or host-related factors that may have contributed to death. Clinical signs appeared 23 days after feeding of milk replacer commenced. Of 85 calves examined, 64 had pneumonia (75.5%), 62 had ocular signs (72.9%), 46 had diarrhea (54.1%), 34 were anorectic (40.0%), 15 were bloated (17.6%), 8 had cardiac arrhythmias (9.4%), 3 had convulsions (3.5%), and 3 were polydipsic/polyphagic (3.5%). Clinical signs began to appear when calves each were being fed approximately 1.5 to 2.0 g of zinc/day and exposed to a cumulative zinc intake of 42 to 70 g, from a milk replacer containing 706 micrograms of elemental zinc/g of milk replacer. Of 95 calves studied, 1 died before zinc was supplemented, 16 died during the episode, 12 were euthanatized, 1 was lost to follow-up evaluation, 1 was culled, and 64 were slaughtered. Deaths attributable to zinc toxicosis were observed between 25 and 53 days after the milk replacer was supplemented with zinc. Calves died while being exposed cumulatively to 30 to 66 g of zinc. The factors of previous pneumonia severity, age, cumulative daily exposure to zinc, and calf location within a bay were examined for possible associations with mortality, using stepwise logistic regression. Though younger calves tended to have a higher mortality than older calves, neither age category nor severity of pneumonia, before zinc supplementation, accounted for a significant mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1987

Economic losses from an episode of zinc toxicosis on a California veal calf operation using a zinc sulfate-supplemented milk replacer.

An episode of zinc toxicosis in 95 veal calves caused $29,602 in losses to the producer ($315/affected calf), most of them direct, out-of-pocket losses. Increased calf mortality and increased veterinary service costs accounted for a majority (70%) of the losses. Reduction of losses may have been accomplished by removing the source and increasing the roughage content in the diet, or by shipping the animals for immediate slaughter. Given the magnitude of the financial loss, especially those associated with calf mortality, it was concluded that producers should refrain from using large amounts of mineral supplements unless a deficiency has been diagnosed.

Animal Feed↗
PubMed1986

Epidemiologic and economic analyses of an unusually long epizootic of trichomoniasis in a large California dairy herd.

An epizootic of trichomoniasis in a large California dairy herd caused an estimated economic loss of $66,538 ($665/infected cow). Greatest losses were caused by infertility (about 50% of losses caused by excess days open). The disease continued in the herd, despite culling older bulls and replacing them with young uninfected bulls and despite institution of an artificial insemination (AI) breeding program for 2 high-production strings. The AI breeder's practice of checking for estrus by vaginal examination was implicated in the spread of the disease. Of 5 cows that became infected before or at conception, 1 had the infection throughout the gestation period and into the next lactation. The prevalence of trichomoniasis in the herd (estimated on the basis of culture results) was 10.67%. The culture method had a calculated sensitivity of only 58.7%. Of 940 cows in the herd, 132 aborted during the epizootic (8 aborted twice); 45 abortions would have been expected in a dairy herd of this size in the absence of trichomoniasis. In high-density mass-bred herds, conditions and/or management practices may be conducive for trichomoniasis transmission, and generally recommended control programs should be adjusted on such dairies. In particular, dairy operators should not assume that culling older bulls and replacing them with young uninfected bulls and that institution of an AI program will be effective in limiting the spread of the disease. Moreover, a diagnostic test with improved sensitivity would greatly assist in the identification of infected cows.

Abortion, Veterinary↗
PubMed1985

Economic impact of an epizootic of bovine vesicular stomatitis in California.

A recent outbreak of vesicular stomatitis in California's San Joaquin Valley caused economic loss at 2 dairies of $225,000 during a 2-month period. These losses amounted to $202/cow for dairy 1 and $97/cow for dairy 2. The most notable economic losses were associated with high cull rates. The rapid spread of the disease (attack rates were 72% in 66 days for dairy 1 and 38% in 41 days for dairy 2) suggests that high-density herds particularly may be vulnerable to the disease. Factors that may have accounted for this rapid spread included common water troughs, open corrals, and inability of the dairy operator to isolate cows due to lack of space.

Animals↗
PubMed1982

Why the dairy industry does not make greater use of veterinarians.

Interviews with 32 large-scale dairy operators in Tulare County, Calif, indicated that as large-scale dairies have replaced smaller dairies, the operator's reliance on the veterinarian as a primary source of advice about a wide range of dairy health management issues has declined. Large dairies require an integrated approach to herd management, ie, herd health, herd management, and production. Dairy operators do not look to veterinarians to provide this integrated approach, instead relying on feed representatives, nutritionists, accountants, and staff of dairy cooperatives. Operators perceive veterinarians as primary providers of clinical services only. As veterinarians have little conflict of interest or vested interest in giving advice about nutrition, proper facility design, and other general management issues, this perception of the veterinarian as a clinician only deprives the dairy operator of an objective appraisal of herd health, management, and production. Changing this perception will require a restructuring of many veterinary medical school curricula, with an emphasis on courses in epidemiology, preventive medicine, herd management, nutrition, and similar courses.

Animal Husbandry↗
PubMed1979

Estimation of economic loss associated with anaplasmosis in California beef cattle.

On the basis of questionnaire surveys and personal interviews with veterinarians, ranchers, and livestock farm advisors, the seriousness of anaplasmosis in California was determined. In 1976, the economic loss due to anaplasmosis in the study sample of beef cattle was $2,203,150. When inferences were made from the sample population to include the whole population of beef cattle, this loss was estimated to be $5,244,319. These values were in contrast to a farm advisors' estimate of $11 million loss due to anaplasmosis, which was included in a total estimated loss of $300 million due to all livestock diseases of economic importance in California. It appeared that anaplasmosis, although having a substantial economic impact in California, is not as economically devastating as it was once thought to be. It was concluded that private programs currently in use (vaccination and treatment) are sufficient to control anaplasmosis.

Anaplasmosis↗