Search PubMed⌕ Search

Biomedical subjects

G H Schmidt

Publications and source records attributed to G H Schmidt.

At least 55 records · Page 3Linked to original sources
PubMed1982

Effectiveness of educational efforts in implementing mastitis control procedures in commercial dairy herds.

One hundred-fifty diarymen in north-eastern Ohio, whose herds had a history of persistently high Wisconsin Mastitis Test scores, were invited to participate in this project, with 43 agreeing to do so. These dairymen were divided into two experimental groups and one control group to determine the effectiveness of two intensities of educational effort on adoption of mastitis control procedures and to demonstrate the effectiveness of mastitis control recommendations. A teat dipping and dry cow therapy program was adopted by more herds in the group with intense educational effort than in the intermediate or control group. Percents of herds in each group utilizing this program in 1977 (start of project), 1978, and 1979 were 8, 75, and 92 for the intense group; 30, 50, and 50 for the intermediate group; and 10, 27, and 27 for the control group. Prevalence of infection declined more rapidly in the intense group with 42, 28, and 24% of cows infected; 39, 25, and 30% in the intermedia, and 56, 35, and 42% in the control group in 1977, 1978, and 1979. Those herds adopting a teat dipping and dry cow therapy program had infection prevalence of 41, 25, and 20% of cows; bulk tank Wisconsin Mastitis Test scores of 15.5, 14.7, and 11.4; and milk production per cow per day of 18.4, 18.4, and 17.5 kg in 1977, 1978, and 1979.

Animals↗
PubMed1980

Mammary implant shell failure.

The author critically examined removed implants, and found that the sac of both inflatable and gel mammary implants may perforate due to wear or erosion.

Breast↗
PubMed1978

Change in udder health and overmilking.

Removing milker units as soon as milk flow stopped was compared to milking for a fixed time of 12 min in an 8-wk trial with 60 cows. Teats were dipped in broth culture of approximately 10(9) colony forming units per ml of Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus uberis for 4 wk. More new infections of quarters occurred in the 12-min group. In trials 2 and 3, 20 additional cows were milked with automatic milking machine detachers and 20 cows were milked with a flow control unit for 12 min each trial. New infection rates were highest in the two groups milked for 12 min. Age for lactation and cows were associated with most of the variation in the new infection rate. Cows with pointed teat ends had the highest rate of new infection. Effects of fixed-time milking on increased mammary infection and clinical mastitis were small.

Animals↗
PubMed1975

Epinephrine inhibiting milk ejection in lactating cows.

Blood oxytocin was determined on 10 Holstein cows during normal milking and during milking when epinephrine was injected intravenously before or after udder stimulation. The average peak oxytocin concentration during normal milking was 399.7 muU/ml plasma and was reached at 1 min after teat cup application. Oxytocin concentration in blood plasma declined rapidly after peak concentration and dropped to 30.5 muU/ml plasma within 4 min after the start of milking. By 5 min after removal of the teat cups, it had declined to less than 4 muU/ml plasma. The administration of epinephrine, either before or after udder washing, inhibited milk ejection as indicated by milk production and oxytocin concentrations. Peak oxytocin concentrations were 1.05 muU/ml plasma 1 min after teat cup application when epinephrine was injected before udder washing and 8.6 muU/ml plasma at teat cup application when epinephrine was injected after udder washing. These results and the use of a beta receptor blocker to inhibit the effect of epinephrine at the myoepithelial cell level indicated that epinephrine inhibited release of oxytocin from the neurohypophysis.

Animals↗
PubMed1975

Release of oxytocin in the cow during milking.

Jugular vein oxytocin concentrations were determined at 15-s intervals on 10 Holstein cows during milking. Oxytocin ranged from .5 muU/ml plasma prior to udder washing to 652.7 muU/ml plasma at 1 min after application of teat cups. The results indicate a gradually increasing release of oxyctocin after stimulation and a maximal oxytocin release 1.5 min after start of udder washing and 1 min after teat cup application.

Animals↗