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Biomedical subjects

J D Roussel

Publications and source records attributed to J D Roussel.

At least 37 records · Page 2Linked to original sources
PubMed1986

Cortisol response in heifers to artificial insemination, natural mating, and no mating at estrus.

Eight mixed-breed dairy heifers were used in a random block design to study the stress-producing effect of various types of mating on heifers. Treatments consisted of artificial insemination, natural mating, or not mating at estrus. Stress was evaluated by measuring blood plasma cortisol. Blood samples were collected by indwelling jugular catheters at 60 and 30 min before treatment; immediately before treatment (0 min); and 5, 15, 30, 60, 120 and 180 min after treatment. Means for cortisol were not significant for treatment or treatment across time. Mean cortisol response to the artificial insemination, natural mating and no mating treatments were 5.36, 8.05 and 5.56 ng/ml, respectively. These results suggest that the use of artificial insemination does not impose and added stress at estrus.

Journal Article↗
PubMed1983

Changes in circulating plasma levels of cortisol in lactating and non-lactating dairy cattle during the estrous cycle.

Plasma cortisol levels were determined by radioimmunoassay for five lactating cows and five open heifers from blood samples collected daily during the course of a complete estrous cycle. Each animal was fitted with an indwelling jugular catheter to minimize stress from bleeding. Mean plasma cortisol levels were 5.67 ng/ml for the lactating cows and 5.87 ng/ml for the open heifers. Mean values for individuals ranged from 3.79 ng/ml to 6.94 ng/ml in the lactating group, and 3.37 ng/ml to 11.69 ng/ml in the open group. These differences, both between and within groups, were not significant. Mean cortisol values during the estrous cycle ranged from 2.26+/-0.93 ng/ml on day one to 9.49+/-2.11 ng/ml on day six for the lactating group, and 2.74+/-0.52 ng/ml on day six to 14.66+/-10.78 ng/ml on day twelve for the open group. Group by day interactions were not significant. Attempts to correlate plasma cortisol with lactation or day of estrus were not significant.

Journal Article↗
PubMed1983

Changes of aldosterone in blood serum of dairy cattle during estrous cycle.

Blood samples were taken daily from five lactating cows and five open heifers beginning with the 1st day postestrus and continuing until the animal was observed in standing estrus. Means of aldosterone in blood serum were 102.6 +/- 5.1 pg/ml for lactating cows and 94.1 +/- 5.1 pg/ml for open heifers. Age and lactation did not appear to be major factors affecting circulating aldosterone in the bovine species. Effect of day of the estrous cycle on aldosterone was quadratic. Concentrations of aldosterone for lactating cows started at 92.3 pg/ml on day 1 of the estrous cycle, peaked at 125.5 pg/ml on day 8, then declined steadily to a low of 43.2 pg/ml on day 20. There was no significant interaction of group by day. During the estrous cycle aldosterone appeared to be related to development of corpus luteum and progesterone. Sodium in blood serum was higher during estrus for lactating cows than open heifers for linear, quadratic, and cubic effects. Although not correlated with aldosterone, sodium exhibited similar cyclic patterns throughout the estrous cycle. Responses between sodium and aldosterone appeared delayed during estrus.

Age Factors↗
PubMed1982

Pregnancy rates relating to plasma progesterone levels in recipient heifers at day of transfer.

A group of Holstein heifers (n=223), weighing approximately 454 kg, were used to determine pregnancy rates in relation to plasma progesterone concentrations in recipients on the day of embryo transfer. All recipients were in estrus within +/- 12 hours of the donor cows. These data showed a cubic trend by regression analysis. Chi-square test revealed that there was a significant (P<0.0001) relationship between plasma progesterone concentrations and resulting pregnancies. Pregnancy rates were low when plasma progesterone concentrations were below 2.00 ng/ml. Actual number of pregnancies relating to specific plasma progesterone groups were 12 61 (20%) for <2.00 ng/ml, 94 127 (74%) for concentrations between 2.00 and 5.00 ng/ml, and 21 35 (60%) for >5.00 ng/ml. Corpora lutea were classified as good, poor, or cystic by both manual and visual observation. These observations revealed that manual palpation of the corpus luteum was not a valid criterion of the corpus luteum function as measured by plasma progesterone concentrations. Further observation revealed no significant relationship between plasma progesterone and whether the corpus luteum was on the left or right ovary. Hence, pregnancy rate was not significantly associated with the left or right ovary. Pregnancies were determined by rectal palpation at 60 days.

Journal Article↗
PubMed1982

Metabolic profile testing for Jersey cows in Louisiana: reference values.

One hundred twenty-seven Jersey cows (1 to 6 years of age) within a 160.93-km radius of Baton Rouge, La, were selected at random over a 3-year period to determine serum values for total creatine kinase, aspartate transaminase, calcium, phosphorus, alkaline phosphatase, cholesterol, total protein, globulin, urea nitrogen, and glucose. Breed and age were partitioned as possible sources of variation. Seasonal temperature and management influences were taken into account by restricting the sampling area. Seasonal temperature and management influences along with reproductive status and stage of lactation, were randomized by sampling over the 3-year period. All serum values, except aspartate transaminase, urea nitrogen, and glucose were influenced by age. Serum cholesterol, total protein, and glucose were influenced by age. serum cholesterol, total protein, and globulin tended to increase with age, whereas creatine kinase, calcium, phosphorus, and alkaline phosphatase generally decreased with age.

Age Factors↗
PubMed1981

Effects of age, temperature-season, and breed on blood characteristics of dairy cattle.

Two hundred twenty four dairy cattle (6 mo to second calving) representing four breeds (169 Holstein, 24 Guernsey, 19 Jersey, 12 Brown Swiss) were used to determine effects of age, temperature-season, and breed on blood characteristics. A total of 1183 blood samples were collected by jugular venipuncture in the middle of each temperature-season. Covariate age affected blood profile except for hemoglobin, oxyhemoglobin, glutamic-oxalacetic transaminase, and albumin. Temperature-season increased or decreased all measures except enzyme creatine phosphokinase, total creatine phosphokinase, calcium and phosphorus. Years differed for all measures except hemoglobin and oxyhemoglobin. Except for enzyme creatine phosphokinase, total creatine phosphokinase, and phosphorus, breeds differed in other measures. There were interactions between temperature-season and year, temperature-season and breed, and year and breed. Differences among temperature-seasons were not consistent from year to year. Breed differences were not consistent from temperature-season to temperature-season for calcium or protein-bound iodine. Breed differences were not consistent from year to year for glutamic-oxaloacetic transaminase, total protein, albumin, or calcium.

Aging↗
PubMed1977

Effect of exogenous corticotropin and climatic conditions on bovine adrenal cortical function.

Interactions between three climatic conditions and exogenous adrenocorticotropin (200 IU) or saline on glucocorticoids of plasma were tested in six pregnant Holstein heifers. Animals were under cold (5 C, 30% relative humidity), thermoneutral (18 C, 50% relative humidity), and hot (35 C, and 80% relative humidity) conditions. Effects of treatment, interactions of environment with treatment, and environment with treatment with interval on glucocorticoids of plasma were measured through timed intervals of blood collection at pre- and postintravenous injection of a treatment solution. Adrenocorticotropin elevated corticoid concentrations in plasma, but interactions of environment with treatment and environment by treatment by sampling interval were nil for responses of corticoids in plasma.

Acclimatization↗
PubMed1977

Response of the nine-banded armadillo (Dasypus novemcinctus) to gonadotropins and steroids.

Adult male and female, nine-banded armadillos (Dasypus novemcinctus) were treated with exogenous gonadotropins and steroids to induce mating in captivity. Gonadotropin treatment induced follicular development and ovulation in the female but failed to enhance semen quality in the male. The number of ovarian follicles increased as the dosage of pregnant mare serum gonadotropin increased; ovulation rate appeared to be inversely related to dose. Mating behavior was not detected in any of the trials, but a pattern of cyclic cytological changes in urogenital smears, which could be used to detect the follicular phase of the estrous cycle, was observed. The modal duration of the estrous cycle was found to be 4 days.

Animals↗
PubMed1976

Effect of temperature-season on bovine adrenal cortical function, blood cell profile, and milk production.

Data collected monthly for one calendar year from Holstein cows lactating under Louisiana ambient climatic conditions comprised a total of 264 cow-months. The year was divided into seasons of cool, intermediate, and hot temperatures. The hot season elicited depressions in circulating corticoids and percent hematocrit. Leukocytosis was a response to increasing ambient temperature primarily accounted for by an increase in circulating neutrophils. Progression from intermediate to hot season gave evidence of eosinophila, and in addition, a relative eosinopenia may have been induced by increased adrenal cortex activity. Milk production was depressed during the hot temperature-season and showed no significant relationship with corticoids of plasma. Rectal temperatures and respiration rates were indicative of heat stress in the hot temperature-season and gave significant negative correlations with circulating corticoid concentration.

Adrenal Cortex↗