Pine needle abortion in cattle: pathological observations

Grazing of ponderosa pine needles by pregnant cows may cause abortion. The abortions are frequently accompanied by retained placenta. Death is not uncommon in cows that abort. Ten cows were placed on a ponderosa pine needle experiment. Six of these cows were fed pine needles and four served as controls. All six cows receiving pine needles aborted, and three of them died shortly after the abortion. Death was due to a severe septicemia. Although the cows were necropsied shortly after death, all tissues were necrotic. Other lesions are described. Three of the six calves died shortly after the abortion. The other three were small and weak but survived due to intensive care.     

Pine needle abortion in cattle: a review and report of 1973-1984 research

Research has verified field observations that cows grazing ponderosa pine needles may abort. The incidence and nature of the abortions produced experimentally simulate very closely those reported by livestock producers and veterinarians. The incidence of experimentally-produced abortions varied markedly from year to year even though the needles were collected in the same general area each year. This suggests that the abortifacient compound(s) in the needles vary from year to year, probably due to environmental and site conditions. The impact of stress (cold and nutrition) as a factor in the abortions was examined. It was concluded that the only effects would be on the willingness of cows to eat the needles. The pine needle abortion problem, what is known of the etiology, and mechanisms of the abortion are reviewed. The usefulness of bioassay systems to study pine needle abortions is discussed.     

Prolactin, estradiol, and progesterone changes in paretic and nonparetic cows during the periparturient period

We studied the relationship of serum prolactin, estradiol-17 beta, and progesterone concentrations to plasma calcium, phosphorus, and free hydroxyproline concentrations, as well as to dry matter intake, in 14 aged dairy cows (mean of 4.5 parities), 7 of which became paretic, from 28 days before to 4 days after calving. Plasma calcium and phosphorus concentrations and dry matter intake decreased more at parturition in paretic cows than in nonparetic cows. Prolactin concentrations were not different between paretic and nonparetic cows, but were variable. Concentrations of estradiol were higher in paretic cows from 15 to 5 days before parturition, whereas hydroxyproline concentration was lower in paretic cows on days 10 through 3 before parturition. Progesterone concentration was lower in paretic cows and decreased earlier at parturition, compared with that in nonparetic cows. The findings suggested that high estradiol concentrations in late pregnancy inhibit bone resorption and predispose aged cows to parturient paresis. The earlier decrease in progesterone concentration at parturition and lower concentrations throughout late pregnancy might have contributed to the greater inappetence in paretic cows at parturition. The importance of prolactin in the pathogenesis of parturient paresis is not clear.     

An abortion storm in cattle associated with neosporosis in Taiwan

An abortion storm associated with acute neosporosis involving 18 cattle was observed in a dairy farm in Taiwan. Aborted fetus age ranged from 3 to 8 months. Of the 38 cattle in that farm examined during the abortion storm, 52.6% (20/38), 13.2% (5/38) and 10.5% (4/38) contained both IgG and IgM, only IgG and only IgM antibodies to Neospora caninum, respectively. No antibody to N. caninum was detected prior to the abortion storm. Follow-up study conducted a year later showed that 23 out of 28 cattle had sero-converted. Since some cattle were positive to either only IgG or IgM, we suggest that both IgG and IgM should be tested for diagnosing neosporosis. Neosporosis surveillance of naive cattle herd is recommended.     

Preovulatory serum estradiol concentration is positively associated with oocyte ATP and follicular fluid metabolite abundance in lactating beef cattle

Cattle induced to ovulate a small, physiologically immature preovulatory follicle had reduced oocyte developmental competence that resulted in decreased embryo cleavage and day 7 embryo quality compared with animals induced to ovulate a more advanced follicle. RNA-sequencing was performed on oocytes and their corresponding cumulus cells approximately 23 h after gonadotropin-releasing hormone (GnRH) administration to induce the preovulatory gonadotropin surge suggested reduced capacity for glucose metabolism and oxidative phosphorylation in the cumulus cells and oocytes from follicles ≤11.7 mm, respectively. We hypothesized that induced ovulation of a small, physiologically immature preovulatory follicle results in a suboptimal follicular microenvironment and reduced oocyte metabolic capacity. We performed a study with the objective to determine the impact of preovulatory follicle diameter and serum estradiol concentration at GnRH administration on oocyte metabolic competence and follicular fluid metabolome profiles. We synchronized the development of a preovulatory follicle and collected the follicle contents via transvaginal aspiration approximately 19 h after GnRH administration in lactating beef cows (n = 319). We determined ATP levels and mitochondrial DNA (mtDNA) copy number in 110 oocytes and performed ultra-high-performance liquid chromatography–high resolution mass spectrometry metabolomic studies on 45 follicular fluid samples. Intraoocyte ATP and the amount of ATP produced per mtDNA copy number were associated with serum estradiol concentration at GnRH and time from GnRH administration to follicle aspiration (P < 0.05). mtDNA copy number was not related to follicle diameter at GnRH, serum estradiol concentration at GnRH, or any potential covariates (P > 0.10). We detected 90 metabolites in the aspirated follicular fluid. We identified 22 metabolites associated with serum estradiol concentration at GnRH and 63 metabolites associated with follicular fluid progesterone concentration at the time of follicle aspiration (FDR < 0.10). Pathway enrichment analysis of significant metabolites suggested altered proteinogenesis, citric acid cycle, and pyrimidine metabolism in follicles of reduced estrogenic capacity pre-gonadotropin surge or reduced progesterone production by the time of follicle aspiration.     

乏情母犬用溴隐亭处理后的发情表现与血清中孕酮和雌二醇水平变化

选择 3只年龄为 3岁处于乏情期的苏北红犬和 6只 1～ 2岁未发情的罗威纳犬 ,用溴隐亭处理后有 4只母犬发情 ,1只母犬受孕而后流产。分析犬血清中雌二醇和孕酮水平 ,发情受孕犬雌二醇和孕酮分泌呈现规律性变化趋势 ;发情未受孕犬在雌二醇分泌峰出现后孕酮分泌不稳定 ;而未发情犬雌二醇和孕酮没有变化。结果表明 ,溴隐亭能够有效地缩短母犬的乏情期 ,溴隐亭处理后不同生理状态母犬反应差异较大 ,发过情的母犬作用明显 ,对从未发过情的母犬效果较差     

Effects of endotoxin infusion on circulating levels of eicosanoids, progesterone, cortisol, glucose and lactic acid, and abortion in pregnant cows

The effects of Escherichia coli endotoxin infusions (1.0 or 2.5 micrograms kg-1 over 6 h) on pregnancy were investigated in cows in the first, second and third trimester of gestation. Endotoxin increased the plasma levels of prostaglandins (PGs), thromboxane B2 and cortisol, and decreased progesterone. The severity of the clinical signs and the magnitude of the increases in plasma PGs, thromboxane B2 and cortisol tended to depend on the dose of endotoxin, but were independent of the gestation period. There was hyperglycemia followed by hypoglycemia and lactic acidemia. Hyperglycemia and lactic acidemia were significant only at the high dose of endotoxin. Endotoxin infusion at both doses caused a preferential mobilization of oleic acid from adipose tissue, and also had some effects on the mobilization of palmitic and stearic acids during the post-infusion period. The cows in the first trimester of gestation were more sensitive to the abortifacient effect of endotoxin than cows in the second and third trimester of gestation. The results of this study indicate that the mechanism of endotoxin-induced abortion in cows initially involves a prolonged release of PGF2 alpha and its subsequent stimulant effect on uterine smooth muscle contraction and luteolytic effect leading to a gradual decline in the plasma levels of progesterone. It was concluded that pregnancy terminates in the absence of an adequate level of progesterone, especially during the first trimester of gestation, when progesterone of extraluteal origin is not yet available, coupled with the PGF2 alpha-induced propulsive contraction of the uterus. In addition, the metabolic and circulatory failures in severe cases of endotoxemia, especially at the high dose of endotoxin, resulting either directly or indirectly via the release of various autacoids, catecholamines and cortisol, may also contribute to the termination of pregnancy at any stage of gestation.     

Estrus, ovulation, and serum progesterone, estradiol, and LH concentrations in mares after an increased photoperiod during winter

On December 11, 1974, 15 seasonally anestrous mares were assigned at random to 1 of 3 experimental groups: outdoor-control, indoor-control, or indoor light-treated (a 16-hour photo-period). This experiment was terminated on April 21, 1975. The five mares in the indoor light-treated group ovulated 59.0+/-6.9 days later, which was 74 days earlier (P less than 0.01) than 2 of the 5 outdoor-controls (the other 3 ovulated after April 21 during a subsequent experiment) and 50 days earlier (P less than 0.05) than the indoor-controls. Durations of the 1st estrus for the 3 groups of mares were 13.3+/-3.6, 8.4+/-2.0, and 6.0+/-1.0 days for the indoor light-treated, indoor-control, and outdoor-control groups, respectively. The indoor light-treated mares averaged 4.2 estrous cycles before April 21, the indoor-control mares averaged 1.4 estrous cycles, and 2 of 5 outdoor-control mares ovulated 1 time during the experiment. The peripheral blood luteinizing hormone (LH), estradiol, and progesterone concentrations were minimal during winter anestrous. The hormone changes normally associated with estrous cycle activity in mares--maximal estradiol and luteinizing hormone concentrations near ovulation and maximal progesterone concentration during diestrus--were observed in all mares beginning at the 1st estrus. Hair loss was observed earlier in the light-treated mares, than in either of the other groups. In conclusion, a 16-hour photo-period initiated in early December for anestrous brood mares caused endocrinologically normal estrous cycles to begin within 2 months. This may allow breeding and foaling considerably earlier than normally expected.     

Technical note: Exit velocity as a measure of cattle temperament is repeatable and associated with serum concentration of cortisol in Brahman bulls

The objectives of this study were 1) to compare temperament assessments, using multiple techniques and over repeated observations, to gauge temperament over the long-term and 2) to evaluate the relationship of the temperament appraisals with serum concentrations of cortisol (CS). Measures of temperament were gathered over 3 repeated observations (60-d interval) of yearling, fall-born Brahman bulls (initial BW = 320 +/- 4 kg; n = 66). Temperament assessments included exit velocity (EV), which was the rate at which the bulls exited the squeeze chute and traversed a fixed distance (1.83 m); pen scores (PEN; 1 = quiet to 5 = excited), ascertained from animal behavior while penned in small groups (n = 5); and chute scores (CHUTE; 1 = quiet to 5 = excited), determined from behavioral responses to restraint on the weigh scale. Temperament measures obtained during the initial data collection (d 0) were all positively correlated (r > or = 0.35, P < 0.005) with one another. Additionally, PEN (r = 0.29, P < 0.05) and EV (r = 0.26, P < 0.05) were positively correlated with CS, whereas CHUTE was not (r = 0.09, P = 0.46). All serial EV measures were positively correlated (r > 0.31, P < 0.02). All PEN were positively correlated (r > 0.31, P < 0.01), whereas serial measures of CHUTE were not (P > 0.3). Exit velocity was positively correlated with CS within d 0 (r = 0.26, P = 0.04) and 120 (r = 0.44, P < 0.01). The EV data obtained at d 0 were transformed into a discrete variable, EV ranking (EV RANK; 1 to 3 scale), in which 1 equated to <1 SD below the mean and 3 equated to >1 SD above the mean. Mean EV (P < 0.01) decreased from d 0 (2.82 +/- 0.07 m/sec) to 120 (2.11 +/- 0.10 m/sec). Time also influenced (P < 0.01) CS; mean CS decreased between d 0 (14.6 +/- 0.7 ng/mL) and 120 (11.1 +/- 0.8 ng/mL). Measures of EV can be a valuable tool for the assessment of cattle temperament and a possible predictor of temperament and stress responsiveness to future animal handling events.     

Effects of hyperlipemia on radioimmunoassays for progesterone, testosterone, thyroxine, and cortisol in serum and plasma samples from dogs

Hyperlipemic serum and plasma samples often are received by clinical laboratories for endocrinologic analysis by radioimmunoassay. We designed a study to determine what effect, if any, hyperlipemia has on estimation of lipid-soluble hormone concentrations determined by solid-phase radioimmunoassays. Progesterone, testosterone, thyroxine, and cortisol concentrations were determined in canine plasma and serum with various degrees of lipemia. Samples of serum, heparinized plasma, and EDTA-treated plasma were obtained from blood collected from 4 female and 4 male Beagles by use of evacuated tubes. To induce hyperlipemia in vitro, IV fat emulsion was diluted in deionized water to produce 0 (water only), 33, 67, or 100% mixtures. Twenty microliters of each mixture then was added to the subsamples of serum and plasma from each dog. Hormone concentrations were determined, using validated radioimmunoassays. Triglyceride concentrations were determined by enzymatic assay. Addition of IV fat emulsion in vitro was an accurate and reproducible means of altering triglyceride concentrations in the samples. Triglyceride concentrations as high as 700 mg/dl had no effect on radioimmunoassays for progesterone, testosterone, and thyroxine in serum, heparinized plasma, or EDTA-treated plasma. Addition of 100% (but not 33 or 67%) fat emulsion reduced the mean cortisol concentration in heparinized plasma by 12% (P less than 0.05). This severe hyperlipemia did not affect quantification of cortisol in serum or EDTA-treated plasma.     

Conceptus elongation in ruminants: roles of progesterone,prostaglandin, interferon tau and cortisol

The majority of pregnancy loss in ruminants occurs during the first three weeks after conception, particularly during the period of conceptus elongation that occurs prior to pregnancy recognition and implantation. This review integrates established and new information on the biological role of ovarian progesterone(P4), prostaglandins(PGs),interferon tau(IFNT) and cortisol in endometrial function and conceptus elongation. Progesterone is secreted by the ovarian corpus luteum(CL) and is the unequivocal hormone of pregnancy. Prostaglandins(PGs) and cortisol are produced by both the epithelial cells of the endometrium and the trophectoderm of the elongating conceptus. In contrast, IFNT is produced solely by the conceptus trophectoderm and is the maternal recognition of pregnancy signal that inhibits production of luteolytic pulses of PGF2αby the endometrium to maintain the CL and thus production of P4. Available results in sheep support the idea that the individual, interactive, and coordinated actions of P4, PGs, IFNT and cortisol regulate conceptus elongation and implantation by controlling expression of genes in the endometrium and/or trophectoderm. An increased knowledge of conceptus-endometrial interactions during early pregnancy in ruminants is necessary to understand and elucidate the causes of infertility and recurrent early pregnancy loss and provide new strategies to improve fertility and thus reproductive efficiency.