Biomedical subjects

R H Foote

Publications and source records attributed to R H Foote.

At least 145 records · Page 8Linked to original sources

PubMed1986

Dose-response shift in the ability of gilts to remain pregnant following exogenous estradiol-17 beta exposure.

Sixty mated gilts were assigned to a 2 X 6 factorial arrangement (n = 5) of day of injection (d 9 and 10 vs 12 and 13; d 0 = first day of estrus) and dose of estradiol-17 beta (0, .125, .5, 2, 8 and 32 mg X gilt-1 X d-1). Gilts were subsequently slaughtered on d 30; pregnancy was verified and percent embryonic survival calculated. A 64-fold shift in the dose-response curve for percent embryonic survival illustrated that the adverse effects of exogenous estradiol-17 beta were less when administered on d 12 and 13 as compared with d 9 and 10 (day X dose, P less than .01). This experiment demonstrated that the uterine-embryonic environment of d 12 and 13 pregnant gilts was more tolerant of exogenous estrogen alterations than that of d 9 and 10 pregnant gilts.

Animals↗

PubMed1986

Postthaw survival and fertility of frozen bull spermatozoa treated with antibiotics and detergent.

Five factorial experiments were conducted, each with 10 bulls, three extenders, and six antibiotic treatments to determine safe levels of new antibiotics to add to bull spermatozoa. Dicloxacillin, cephapirin, ceforanide, gentamicin, and minocin were added at five concentrations to whole milk, egg yolk-Tris, and egg yolk-Tris detergent (sodium triethanolamine lauryl sulfate) extenders with penicillin and streptomycin as a control. Semen was extended to 20 X 10(6) sperm/ml, packaged in .5-ml straws, frozen and stored in liquid nitrogen, and thawed at 35 degrees C for 30 s. Two people assessed postthaw percentage of motile spermatozoa from two straws per treatment. Bulls and extenders always affected sperm motility significantly. Percentage of intact acrosomes of spermatozoa was assessed in selected treatments but did not differ in any experiment. Sodium triethanolamine lauryl sulfate tended to improve cryopreservation of spermatozoa. Percentage of motile spermatozoa in milk declined when concentrations of dicloxacillin exceeded 200 micrograms/ml or when gentamicin, as Gentocin, exceeded 500 micrograms/ml. Minocin was toxic at all levels tested in egg yolk and was nontoxic to sperm in milk extender at concentrations less than or equal to 100 micrograms/ml. Cephapirin and ceforanide were innocuous at all concentrations tested (200 to 2000 micrograms/ml). Fertility with cephapirin (500 micrograms/ml) added to an extender containing control antibiotics resulted in a 56-d nonreturn rate of 75.5 versus 72.1% for the control.

Animals↗

PubMed1985

Normal development of fetuses resulting from Holstein semen processed for sex separation.

Semen from two high fertility Holstein bulls with extensive histories in artificial insemination was specially processed for the purpose of sexing and then frozen. The semen was used to inseminate 200 open crossbred beef heifers carefully selected for reproductive soundness from a much larger group. Animals were inseminated alternately with the semen from one of the two bulls and subsequently slaughtered. There were 96 fetuses, ranging in age from 63 to 88 days, which were carefully examined for general appearance, fetal crown-rump length and body weight. There was no effect of sire on fetal size, but the difference between fetal sexes was significant, with the male fetus being appreciably heavier. The regression of fetal length on fetal age was linear and the regression of fetal weight on fetal age was curvilinear. Fetal age accounted for 92% to 96% of the variation in fetal weight and also in crown-rump length.

Journal Article↗

PubMed1985

Fertility differences among male rabbits determined by heterospermic insemination of fluorochrome-labeled spermatozoa.

Spermatozoa from different bucks were stained with different fluorochromes, mixed, and inseminated heterospermically. By altering the interval between insemination and luteinizing hormone injection, spermatozoa were allowed to reside in the female tract approximately 5, 10, or 15 h prior to ovulation. The number of functional spermatozoa, from each male of a pair used, that was transported to the site of fertilization was estimated by counting total number of differently stained spermatozoa that surrounded or fertilized each oocyte. Spermatozoa from split ejaculates within a male competed against each other equally, indicating that the staining procedure did not affect fertilization or functional spermatozoal transport rates. Three pairs of males with high initial semen quality (greater than 80% motility) differed in fertility primarily due to functional spermatozoal transport. Spermatozoal survival in the female tract and capacitation time played a role in differences in male fertility when heterospermic insemination occurred at variable times relative to ovulation. Differences in fertilization not accounted for by spermatozoal transport ratio raised the possibility that rate of egg penetration due to acrosomal enzyme differences may be important in determining male fertility. Therefore, total acrosin, hyaluronidase, and arylsulfatase activity in spermatozoa from specific bucks used in fertilization experiments were determined. Although there were trends favoring high fertility when enzyme content was higher, the difference was significant only for arylsulfatase in one buck.

Animals↗

PubMed1985

Age-associated changes in nuclear binding of rat uterine estradiol receptor complexes.

Nuclear binding of cytoplasmic estrogen receptors was measured in an in vitro cell-free system, using various mixtures of cytosols and nuclei from uteri of mature (6-9 month old) and senescent (24-25 month old) Wistar rats. Both nuclei and cytoplasmic receptors from senescent uteri were 25-35% less efficient in supporting nuclear binding than those obtained from mature tissues as evidenced by the concentrations of occupiable nuclear acceptor sites. No age differences in association or dissociation constants were observed for the nuclear binding reaction. However, the apparent inability of some aged receptors to bind to the full complement of mature nuclear acceptor sites may indicate a qualitative deficiency in the cytosols of senescent uteri.

Aging↗

PubMed1985

Reproductive performance of Holstein cows administered GnRH analog HOE 766 (Buserelin) 26 to 34 days postpartum.

During the fourth week postpartum, 443 healthy Holstein cows milked thrice daily were randomly divided among four groups to receive 0, 2, 8 and 32 micrograms of the GnRH analog HOE 766. Intervals from calving to first estrus and to first breeding, from breeding to conception and conception rates at first breeding were calculated to measure treatment response, and progesterone was measured in the fat-free portion of milk samples collected twice weekly during the first 4 wk following treatment. Uterine involution at the time of treatment was estimated by palpation per rectum. Twenty percent of the cows examined were classified as having delayed uterine involution (abnormal). By analyzing milk progesterone patterns it was determined that 38% of the animals were in the luteal phase of an estrous cycle when treated. Cows without luteal tissue (less than 1 ng of progesterone/ml milk) given 8 or 32 micrograms of HOE 766 increased in progesterone to greater than or equal to 1 ng/ml within 7 d in 77 and 72% of the cows compared with 40 and 57% for cows receiving 0 and 2 micrograms (P less than .05). This increase in progesterone was followed by a normal estrous cycle within 4 wk in a higher proportion of cows treated with the two higher doses of GnRH analog (87 and 86%) compared with 67 and 70% of those receiving 0 or 2 micrograms of the analog (P less than .005). There were no treatment differences (P greater than .05) for other traits analyzed, but cows with a normal progesterone cycle were observed in estrus and were bred sooner (P less than .01) than those with irregular progesterone patterns. It was concluded that the GnRH analog hastened the onset of normal ovarian cycles in cows milked thrice daily.

Animals↗

PubMed1985

Uterine contractions and fertility following clitoral massage of dairy cattle in estrus.

Lactating and nonlactating Holstein cows received 30 s of gentle clitoral massage to determine its effect on uterine contractility and oxytocin concentrations in blood. Clitoral stimulation caused an immediate single uterine contraction, and this could be repeated at 2.5-min intervals. Oxytocin concentrations did not change during intensive blood sampling following clitoral massage. Thus, the uterine response is interpreted as neurally mediated. Eighteen full-time inseminators were allotted to two groups, balanced so that each day half were inseminating control and half treated animals (5 s of clitoral massage following insemination). The 56-day nonreturns for 2090 controls were 74.3% versus 74.0% for 2049 animals receiving clitoral massage. Heifers were more fertile than cows (81.9% versus 70.6% nonreturns), but there was no indication that clitoral massage altered the nonreturn rate in either age group. Also, the time of day animals were inseminated did not affect nonreturn rate.

Animals↗

PubMed1985

Effect of season and high environmental temperature on fertility of Holstein cattle.

The breeding records and meteorological data for cows with first services between July 1, 1979, and June 30, 1980, in a large Florida herd were analyzed to determine the relationship between temperature and breeding efficiency. Seasonal high environmental temperatures were associated with low breeding efficiency. Increased maximum temperature from 29.7 degrees C during April to 33.9 degrees C during July was associated with a decrease in conception rate on first service from 25 to 7%. Also, the average number of inseminations per conception, based on pregnancy diagnosis 6 to 8 wk after breeding, was higher from May to August (4.5 to 5.3) than from September to April (2.3 to 3.5). Days open were longer for the cows first inseminated during May, June, and July (173, 171, and 167 days, respectively) than during other months (99 to 149 days). Temperature decreases of any magnitude for 1 to 3 days before or after the day of breeding, when maximum temperatures on the day of breeding were greater than or equal to 27 degrees C, were associated with higher pregnancy rates. Also, similar temperature decreases around the time of breeding, below the previously mentioned high maximum temperatures for 20 days before the day of breeding, were accompanied by higher conception rates. Fertility was consistently lower under all temperature changes when maximum temperatures on the day of breeding were greater than or equal to 33 degrees C.

Animals↗

PubMed1985

Motility and fertility of frozen bull spermatozoa in tris-yolk and milk extenders containing amikacin sulfate.

Amikacin sulfate, an aminoglycoside antibiotic, effective against some streptomycin-resistant organisms, was tested in bull semen extended with whole milk and egg yolk-Tris extenders in a 6 X 5 X 2 factorial arrangement. Semen from six bulls was frozen in extenders containing 500, 1000, and 2500 microgram/ml of amikacin, a control containing 500 IU/ml of penicillin plus 1000 micrograms/ml of streptomycin plus 500 IU/ml of polymyxin, and control plus amikacin (1000 micrograms/ml). Semen was frozen in .5 ml polyvinyl chloride straws in liquid nitrogen vapor and stored in liquid nitrogen for 2 wk. Straws were thawed in a water bath at 35 degrees C for 30 s. Postthaw motility of spermatozoa in each treatment was assessed using two straws by two observers independently. At amikacin concentrations of 500, 1000, or 2500 micrograms/ml, the percentage of motile spermatozoa averaged 47, 45, and 36% in whole milk and 52, 46, and 46% in egg yolk-Tris. Control and control plus amikacin (1000 micrograms/ml) were 49 and 47% in whole milk and 48 and 52% in egg yolk-Tris. Only amikacin in milk at 2500 micrograms/ml, depressed sperm motility. A fertility trial was conducted to compare the control mixture of antibiotics in whole milk with whole milk also containing 500 micrograms/ml of amikacin. The nonreturn rate to 1182 first service inseminations with semen treated with amikacin (500 micrograms/ml) plus control antibiotics was 70.4% compared with 70.5% for 1494 first service inseminations with control semen. Amikacin can safely be added to whole milk and egg yolk-tris extenders to control streptomycin-resistant organisms.

Amikacin↗

PubMed1985

Counting mammalian spermatozoa in biological fluids containing particulate matter.

Accurate counting of spermatozoa in biological fluids by particle counters requires elimination of competing background. This was accomplished by dissolving cell organelles and other lipid and proteinaceous material with sodium dodecyl sulfate to leave the sperm nucleus. Progress of selective dissolution of interfering background versus sperm nuclei was monitored by phase contrast microscopy. Rabbit semen was diluted in 2.5% sodium dodecyl sulfate (wt/vol) and then 1:1 (vol/vol) with .5 M sodium hydroxide. Suspensions were incubated, diluted 1:200 in .1 M sodium citrate-.1% Triton-X, and counted after 5, 10, and 20 min with a Coulter Counter. All treatment times resulted in similar mean counts, ranging from 367 to 369 X 10(6) sperm/ml. These means were slightly higher than the 350 X 10(6) sperm/ml for hemocytometer counts, but the correlation with hemocytometer counts was r greater than or equal to .98. Bull semen was diluted in either 1) citrate-Triton-X, 2) .25 M Tris-20% egg yolk, or 3) heated whole milk and further treated with 10% sodium dodecyl sulfate and .5 M sodium hydroxide. After 15 min, treated samples were diluted 1:200 in citrate-Triton-X and counted. Following treatment, estimated sperm concentration in the three diluents was not different from that of untreated sperm in citrate-Triton-X. The procedure was successfully applied to bull sperm diluted in milk and packaged in .5-ml French straws used routinely for artificial insemination.

Animals↗

PubMed1985

Prostaglandin F2 alpha-induced estrus in open cows and presumed abortion in pregnant cows with unobserved estrus in a herd monitored by milk progesterone assay.

Data were obtained in a large Florida herd of about 1800 Holstein cows. All cows were inseminated by the herdsman who did the pregnancy checks and who also administered drugs. The herdsman injected 103 cows with prostaglandin F2 alpha during the time this herd was under continuous observation by the authors who were conducting an unrelated research project. These cows consisted of 86 open (never bred) cows which had no estrus observed during the first 70 days postpartum, or no second estrus observed within 30 days after a previous estrus, and 17 cows previously inseminated. Two-thirds (57) of the 86 open cows were in estrus within 4 days. The 17 previously inseminated cows appeared to be pregnant, based upon progesterone profiles, when these were inadvertently given prostaglandin F2 alpha by the herdsman. Progesterone declined in all cows and they were in estrus in 7 +/- 4 days (mean +/- standard error). This result of presumed abortion reflects the luteolytic effectiveness of the drug and the importance of instructing any laymen users to follow necessary precautions to avoid undesirable effects.

Abortion, Veterinary↗

PubMed1985

The use of milk progesterone and electronic vaginal probes as aids in large dairy herd reproductive management.

In a large herd 427 cows were examined for reproductive condition 26 to 34 days after calving. Progesterone profiles were obtained from a total of over 5000 milk samples which were taken twice weekly for 4 weeks, starting at the time of examination, and again 21, 23, and 25 days later. Researchers lived on the farm during the experiment to sample cows and record all data. Electronic probe measurements of cervical-vaginal mucus also were obtained. All cows were inseminated artificially with frozen semen from one organization. Eleven percent of the cows were not inseminated in the estrual phase as determined by substantial concentrations of progesterone in milk (MP), and 2% were pregnant and aborted following insemination. The MP 23 to 25 days after insemination essentially was 100% accurate in predicting nonpregnancy and was preferable to day 21. When used in conjunction with MP on the day of insemination pregnancy prediction 23 to 25 days after insemination was 84% accurate. Non-return rate 60 days after insemination was 7% higher than palpated pregnancy rate. The use of electronic probes under large herd conditions was labor intensive and did not give repeatably distinctive values at estrus.

Abortion, Veterinary↗

PubMed1984

Toxicologic studies with male sheep grazing on municipal sludge-amended soil.

Growing sheep were grazed for 152 d on grass-legume forage growing on soil that had been amended with municipal sewage sludge from Syracuse, N.Y., at 224 metric tons per hectare. Cadmium was higher, but not significantly (p greater than 0.05), in tissues of sheep fed the sludge-grown forage as compared to controls. No significant differences between the sludge or control treatments were found in weight of the complete or cauda epididymis or in percent progressive motility of cauda epididymal sperm. The sludge-treatment group had significantly larger testes (p less than 0.025) when expressed as a percentage of body weight, and higher blood uric acid values (p less than 0.05). There were no observable changes in tissue ultrastructure of liver, kidney, muscle, or testes as examined by electron microscopy in either of the treatment groups. There were no significant differences for rate of animal weight gain, carcass weight, dressing percentage, or quality or yield grade of the carcases between the treatment groups.

Animals↗

PubMed1984

Effects of in vivo estradiol administration on availability of rat uterine nuclear acceptor in measured in vitro.

Estradiol injected in vivo successfully completes for binding to uterine nuclear acceptor sites measured by the assay of Kon and Spelsberg (1). Such competition is time-and dose-dependent, with maximal inhibition (75%) 1 h after injection and at a dose of 10 micrograms of 17 beta-estradiol per 300 g of BW. Thus, this assay appears to accurately measure those uterine nuclear acceptor sites mediating estrogen action in vivo.

Animals↗

PubMed1983

On the negative feedback regulation of gonadotropins in castrate and intact cattle with comparison of two FSH radioimmunoassays.

Two homologous radioimmunoassays for bovine follicle stimulating hormone (bFSH) were utilized in comparing the differential regulation of FSH and luteinizing hormone (LH) in response to ovariectomy or administration of gonadal steroids in cattle. There appeared to be significant LH cross-reactivity in one of the bFSH systems (bFSH-HS-2-17), but not in the other (bFSH-BP3). Concentrations of FSH in plasma measured by these two systems suggested both qualitative and quantitative differences. Following ovariectomy in heifers, LH concentrations in plasma were increased by 7.5 h, while FSH (measured in the bFSH-BP3 system) was not significantly elevated until 18 h. Administration of 200 micrograms of estradiol-17 beta to ovariectomized heifers inhibited levels of FSH in plasma but large doses of testosterone (100 mg), androstenedione (400 mg) and dihydrotestosterone (800 mg) had no effect. Similarly, LH was not affected by the androgens, while estradiol induced LH surges, leading to increased mean LH concentrations. In contrast to the results in heifers, LH concentrations in plasma from steers were inhibited by administration of androgens as well as by estradiol. In steers, FSH (bFSH-BP3) was marginally inhibited by estradiol and not at all by the androgens. Differences in the secretory patterns of FSH and LH also occurred in intact heifers during the estrous cycle. The 72-h period preceding estrus (follicular phase) was characterized by rapidly declining serum progesterone concentrations, followed by concurrent increases in both LH and estradiol. The circulating levels of bFSH (BP3) tended to decline during this interval. Overall, during the estrous cycle, progesterone levels were positively correlated with bFSH-BP3 (r = .37) and negatively correlated with LH (r = -.39). The gonadotropins were not significantly related (r = -.15). These relationships are consistent with the concept that LH controls the final stages of follicular development in cattle and that FSH may exert only a permissive effect.

Androstenedione↗

PubMed1982

Migration of fresh and cryopreserved human spermatozoa in polyacrylamide gel.

The ability of freshly collected and frozen human spermatozoa to migrate in round capillary tubes containing specially formulated polyacrylamide gel was investigated, using 33 ejaculates from 27 donors. Each semen sample was divided; one portion was left undiluted, and the other portion was diluted to 50 x 10(6) sperm/ml. Glycerol was used as the cryoprotectant. The percentage of motile sperm cells was determined before and after freezing. Fresh semen contained a higher percentage of motile cells, which migrated farther than those of cryopreserved-thawed semen. Various correlations between the percentage of motile sperm and migration distance ranged from 0.57 to 0.62. There was a low positive correlation of migration distance with sperm cell concentration per milliliter, r = 0.25 to 0.34; and thus adjusting semen samples to a standard sperm concentration improved the accuracy of the test only slightly. The regression coefficient of migration distance on the percentage of motile sperm in fresh semen was 0.65, indicating that for each 10% increase in sperm motility, migration distance is predicted to increase 6.5 mm. Five batches of polyacrylamide gel gave uniform results, and the application of this stable gel to fertility investigations is discussed.

Acrylic Resins↗

PubMed1982

Separation of bovine spermatozoa by density on water insoluble Newtonian gels and their use for insemination.

Bovine spermatozoa were separated into different density subpopulations utilizing water insoluble hydrocarbon and silicone gels of defined specific gravity. Sperm density profiles were generated for 13 bulls. The separations were found to be repeatable and characteristic of the bull examined. Considerable density variation among animals was demonstrated. Analysis of the separated spermatozoa, before and after freezing, demonstrated that good motility and acrosomal integrity of spermatozoa were maintained. When the least dense fraction of spermatozoa was used for insemination, conception rates were similar to those obtained routinely by artificial insemination with unfractionated spermatozoa. Therefore, this system may be useful in separating spermatozoa of various densities and for removing extraneous matter from semen. However, the sex ratio, among 51 60-day-old fetuses recovered from heifers inseminated with the lowest density fraction of spermatozoa, was 26 males:25 females.

Acrosome↗

PubMed1982

Effects of amikacin sulfate on the motility of stallion and bull spermatozoa at different temperatures and intervals of storage.

Because microfloral content of stallion semen tends to be high, and strains may be resistant to commonly used antibiotics, amikacin was tested with stallion semen and compared with bull semen. Nine ejaculates to stallion semen were incubated at 37 C in egg yolk-tris extender for 0, 2, 4, 6, 8 and 10 h in the presence of amikacin concentrations of 0, 50, 100, 250, 500, 1,000 and 10,000 microgram/ml, with penicillin and penicillin-streptomycin as controls. Averaged over all incubations, spermatozoal motility was 44, 48, 49, 46, 45, 45 and 19%, for increasing concentrations of amikacin, compared with 52 and 47% for penicillin and penicillin-streptomycin controls. The 10,000 microgram/ml concentration of amikacin was the only treatment that suppressed sperm motility (P less than .01). Amikacin (0, 50, 100, 250, 500, 1,000 2,500, 5,000 and 10,000 microgram/ml) and 1,000 IU of penicillin G plus 1,000 microgram of streptomycin/ml or 10,000 IU of penicillin G/ml were added to nine ejaculates of bull semen stored at 4 C in egg yolk-tris extender, and evaluated after 0, 1, 3, 5 and 7 d. The percentage of motile spermatozoa, with increasing levels of amikacin, was 66, 67, 66, 64, 67, 68, 74, 68 and 53%, respectively. Amikacin, at 2,500 microgram/ml, resulted in the highest (P less than .01) motility compared to the other levels of antibiotics after 7 d storage. Both 10,000 microgram of amikacin and 10,000 IU of penicillin G/ml depressed (P less than .01) the mean percentage of motile bull spermatozoa. These studies demonstrate that high concentrations of amikacin can be added to stallion and bull semen without depressing motility of spermatozoa.

Amikacin↗