Excretion of [3H]prednisolone in clinically normal and experimentally infected bovine udders

The excretion rate of [3H]prednisolone from clinically normal and experimentally infected udders of 10 lactating cows was studied. Each quarter of 6 cows was injected with a single dose of [3H]prednisolone mixed with non-radioactive prednisolone equivalent to 10 mg in 10 ml of peanut oil base. Each of the remaining 4 cows was given 40 mg of nonradioactive prednisolone and [3H]prednisolone in 60% ethanol IV. Control and postadministration samples of blood, milk, and urine were examined for radioactivity. The effects of [3H]prednisolone were evaluated in the same cows, first in clinically normal udders, then 2 weeks later in udders experimentally infected with Streptococcus agalactiae. Absorption and elimination of prednisolone were the same before and after induced infection. Within 3 hours after intramammary injection, 95% of the labeled prednisolone was absorbed systemically, less than 5% of this dose was recovered in milk, and 29% was excreted in urine. After IV injection of [3H]prednisolone, less than 0.2% of the total radioactivity was recovered in milk and less than 46% was excreted in urine. Clinical mastitis induced by S agalactiae was moderate. Circulating blood leukocytes and somatic cells in the milk of normal cows remained essentially unchanged. The leukocyte response to induced infection was rapid in blood and milk. Large numbers of leukocytes were noticed in the milk and a severe leukopenia occurred. Prednisolone treatment did not alter the number of somatic cells in milk or reduce the inflammatory response of experimentally infected cows.     

Growth patterns of Angus, Hereford and shorthorn cattle. I. Comparison of inbred and noninbred lines, changes in patterns over time and effects of level of inbreeding and reproductive performance

Mature weight (A) and rate of maturing (K) were estimated for 283 Angus, 140 Hereford and 280 Shorthorn cows utilizing the asymptotic regression equation Yt=A(1-Be-Kt). The Yt was weight of the individual at age t; and B was an estimate related to early life weight changes and provided for a Y-intercept (A-B). Each breed consisted of four inbred and two noninbred lines. Regression of estimated growth curve parameters on levels of inbreeding of the individuals and of their dams and effects of early reproductive performance (EREPRO) were studied as sources of variation in addition to line differences and trends in line values over years. Considered jointly with inbreeding of the dam and with EREPRO, inbreeding of the individual was negatively related (P less than .01) to estimates of A in the three breeds and unrelated (P greater than .10) to estimates of K. Each 1% increase in inbreeding of the individual was associated with about 2 kg decrease in estimated mature weight. An increase in inbreeding of the dam of an individual was negatively related to estimates of K in Angus (P less than .01) and Shorthorns (P less than .05). Inbreeding of dams was positively related to estimates of A in the three breeds, but only in Shorthorns could the relationship be declared significant. Estimates of A were about 46 kg heavier and estimates of K about .010 less for each year an individual failed to produce a calf during her first three opportunities. In general, A values declined in all three breeds during the study. Significant changes were observed in all Hereford analyses and after inbreeding was included in the Angus analysis, while inclusion of inbreeding in the Shorthorn analysis caused the change to become unimportant. The K values increased in all three breeds during the study; however, the change could be declared significant only in Herefords.     

Endocrine regulation of fetal and postnatal meat animal growth

Evidence is discussed which indicates that nutrient partitioning between muscle and adipose tissue can be altered by growth hormone administration in meat animals. In the limited number of studies conducted with meat animals, growth rate, feed efficiency and carcass composition were improved by growth hormone administration. When insulin was administered to normally growing swine no improvement in growth performance was observed. The mechanisms by which growth hormone affects growth performance are not clear but considerable data from rodent studies exist to indicate that many of the growth promoting effects of this hormone are due to somatomedins. However, few data are available for meat animals to indicate whether the growth promoting effects of growth hormone are mediated by somatomedins. Knowledge about the mechanisms that regulate growth hormone synthesis, secretion and biological action is accumulating. It is apparent that growth hormone administration induces an insulin-resistant state in rodents and meat animals. It is not clear whether chronic growth hormone administration in meat animals induces a growth hormone resistant state. Based on the available information, manipulation of systemic hormone concentrations and(or) tissue sensitivity to hormones involved in growth and differentiation may result in means to manipulate fetal and postnatal growth and development.     

Haemodynamics, blood gas and metabolic changes after anaesthesia with chloral hydrate and magnesium sulphate in camels (Camelus dromedarius)

The effects of chloral hydrate and magnesium sulphate (1:1, 10 per cent solution) were evaluated in six healthy adult camels. A dose of 1 ml kg-1 was used. These agents produced satisfactory anaesthesia with good muscle relaxation. The changes in the electroencephalogram showed that the anaesthetic effect lasted for 45 to 60 minutes. Tachycardia and hypotension were moderate and within safe limits. Electrocardiogram studies showed ST segment elevation and primary T wave changes. The acid-base status, blood gas tensions, haemoglobin concentration, blood glucose level and the plasma concentration of total protein, sodium, potassium and chloride were not altered.     

Application of a linear programming model to the control of African trypanosomiasis

A linear programming (LP) model was designed to evaluate trypanosomiasis control activities in south-western Ethiopia. The objectives included maximizing net benefits, utilization of unskilled labor, and resettlement of reclaimed land, and decreasing the prevalence of trypanosomiasis from 20% to less than 5% at the end of 5 years, subject to epidemiological, ecological and economic constraints. The model was a multiperiod specification with 127 equations and 81 activities for the project period of 5 years. The optimal solution required reclamation of 5221 km² of tsetse infested land and used treatment of cattle at maximal levels. At the end of the project period, the prevalance decreased to 2% with net benefits of E$1.281 million. LP provided a potentially optimal means of resource allocation in the short run and a means of identifying those restrictive resources which could be vital to long range planning.     

Pitfalls in immunofluorescence testing in dermatology. III. Pemphigus-like antibodies in the horse and direct immunofluorescence testing in equine dermatophilosis

Indirect immunofluorescence testing for pemphigus-like antibodies was performed on 79 horses: 28 horses with various nonpemphigus dermatologic diseases, 21 horses with various nondermatologic diseases, and 30 normal horses. Pemphigus-like antibodies were detected in 6 horses: 3 normal horses with titers of 1:40, 2 horses with dermatophilosis at titers of 1:10 and 1:80, and 1 horse with lymphosarcoma at a titer of 1:320. It was concluded that equine pemphigus-like antibodies are a potential source of misinterpretation and misdiagnosis in indirect immunofluorescence testing. Direct immunofluorescence testing for whole immunoglobulin, IgG, IgM, and IgA was performed on skin lesions from 2 horses with dermatophilosis. Diffuse intercellular deposition of whole immunoglobulin and IgG was found in both horses. It was concluded that equine dermatophilosis is a potential source of misinterpretation and misdiagnosis in direct immunofluorescence testing.