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1.
Pine needle abortion in cattle: pathological observations   总被引：1，自引：0，他引：1  
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.  相似文献   

2.
Nineteen spring-calving cows were used in an experiment to study the effect of feeding pine needles on incidence of premature parturitions (abortions) and the associated changes in serum cortisol, estradiol-17 beta and progesterone. The study was conducted over 2 years (1983, seven cows fed pine needles and three controls; 1984, six cows fed pine needles and three controls). Experimental feeding started at an average of 250 d of gestation and continued until parturition. Daily blood samples were taken from the start of feeding through 2 to 4 d after parturition. Feeding pine needles shortened gestation by 16 d and induced a premature normal rise in cortisol and estradiol-17 beta associated with parturition. Cortisol concentrations were also high at the beginning of the bleeding period and remained higher in pine needle-fed cows. An abrupt rise in progesterone concentration occurred after the start of pine needle feeding which then decreased sharply for 7 to 8 d before parturition and did not decrease to control concentrations until after parturition. We conclude that feeding pine needles to pregnant cows in late gestation causes abortions and that these abortions are directly caused by or are associated with changes in steroid metabolism.  相似文献   

3.
We studied the frequency and timing of abortion and the serum levels of 17β-estradiol and progesterone in Korean native cows fed pine needles during pregnancy. Fifteen pregnant cows were randomly assigned to groups of 5. The control group was fed a concentrate and rice straw, and the other 2 groups were fed, in addition, either 1.3 or 2.7 kg (dry weight) of Korean pine needles daily, starting at an average of 91 d of gestation and continuing until 245 d of gestation. The health status of the dams and the viability of the fetuses were ascertained by rectal palpation and ultrasound scanning during pregnancy. Simultaneously, blood samples were collected for analysis of serum 17β-estradiol and progesterone. Two abortions in mid-pregnancy (at 126 and 150 d of gestation) occurred in the group ingesting the higher daily amount of pine needles. Premature parturition occurred at 259 d of gestation in this group and at 241 and 252 d of gestation in the group ingesting the lower daily amount of pine needles. The serum 17β-estradiol concentration was significantly higher (P < 0.05) at 4 mo of gestation and the serum progesterone level significantly lower (P < 0.05) at 8 mo of gestation in the group ingesting more pine needles daily than in either of the other 2 groups. These results suggest that the ingestion of pine needles may play a role in abortion in Korean native cows by increasing the serum 17β-estradiol concentration and decreasing the serum progesterone concentration.  相似文献   

4.
We determined whether cows in low (LBC) or high body condition (HBC) would consume different amounts of green pine needles (Pinus ponderosa). Cows (mature; open Hereford and Hereford x Angus) were fed a maintenance basal diet (alfalfa pellets) for Exp. 1 and 2; during Exp. 3 and 4, cows were fed high-protein and high-energy diets, respectively. Experiment 5 was a grazing study on rangeland during winter in South Dakota; diets were determined by using bite counts. Mean BCS (1 = emaciated, 9 = obese) was 7.5 for HBC cows and <4.0 for LBC cows during the experiments. During Exp. 1, LBC cows consumed more (P = 0.001) pine needles than did HBC cows (5.5 +/- 0.25 vs. 1.0 +/- 0.14 g/kg of BW daily, respectively). During Exp. 2, there was a day x treatment interaction (P = 0.001) as LBC cows consumed variable, but greater, amounts of pine needles than did HBC cows (3.7 +/- 0.19 vs. 1.3 +/- 0.12 g/kg of BW daily, respectively). When fed a high-protein/low-energy diet, LBC cows ate more (P = 0.04) pine needles than did HBC cows. When fed a low-protein/high-energy diet, there was a day x treatment interaction (P = 0.001) because LBC cows consumed more pine needles than did HBC cows for the first 3 d of the study, and then consumption by LBC animals decreased during the last 4 d. These experiments suggest that the protein:energy ratio may be an important factor in the ability of cows to tolerate terpenes, and that cows were not able to sustain an increased quantity of needle consumption on a low-protein diet. During the 25-d grazing study, there was a day x treatment interaction (P = 0.001) as LBC animals selected more pine needles (up to 25% of daily bites) on some days compared with HBC cows. Weather influenced pine needle consumption because pine needle bites by LBC cows were related (r(2) = 0.60; P = 0.001) to days of greater snow depth and lower minimum daily temperatures. Both LBC and HBC cows increased selection of pine needles from trees during cold, snowy weather, but the magnitude of the increase was greater for LBC cows. The LBC cows consumed more pine needles than did HBC cows in all experiments, except when cows were fed a low-protein diet. This study indicates that both body condition and protein intake are important factors in pine needle consumption.  相似文献   

5.
Consumption of Ponderosa pine needles by late-pregnant beef cows results in the premature delivery of a viable calf. We have demonstrated the presence of a factor(s) in plasma from cows fed pine needles that specifically increased uterine arterial tone (i.e., decreased arterial diameter) in vitro. This study was designed to investigate changes in uterine blood flow and steroid secretion/uptake by the gravid uterus of cows fed pine needles to induce premature parturition. Sixteen beef cows were laparotomized on d 240 of gestation, and an electromagnetic blood-flow probe was placed around the uterine artery supplying the gravid horn. Cows were randomly assigned on d 250 of gestation to a control (n = 8; 8.2 kg/d of alfalfa hay) or pine needle (n = 8; 2.7 kg/d of pine needles + 5.5 kg/d of alfalfa hay) diet. Uterine blood flow was monitored, and systemic blood (uterine arterial and[or] jugular venous) and uterine venous blood samples were collected daily between 0630 and 0800, just before feeding. Five of eight cows fed pine needles calved prematurely (average day of gestation = 260.2 +/- .6) compared with cows fed the control diet, which calved on 287.6 +/- 3.4 d of gestation. Uterine blood flow in the control cows remained constant from d 250 through the day of parturition. In contrast, uterine blood flow of cows fed pine needles that calved early decreased progressively (P less than .01), declining to 25.2% of its original value by the day of parturition.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

6.
Anecdotal reports suggest that abortion occurs in New Zealand cattle after ingestion of macrocarpa (Cupressus macrocarpa). The clinical signs observed are similar to those seen in abortions caused by ponderosa pine (Pinus ponderosa Laws). Isocupressic acid has been identified as an abortifacient component of the needles of ponderosa pine. Macrocarpa collected from the Palmerston North area contained 0.89% and 1.24% isocupressic acid, compared to 1.70% isocupressic acid in Ponderosa pine needles from Oregon in the United States as analysed by the USDA-ARS Poisonous Plant Research Laboratory. These findings support observations that macrocarpa causes abortion in late gestation cattle in New Zealand and suggest the causal agent is probably isocupressic acid.  相似文献   

7.
Anecdotal reports suggest that abortion occurs in New Zealand cattle after ingestion of macrocarpa (Cupressus macrocarpa). The clinical signs observed are similar to those seen in abortions caused by ponderosa pine (Pinus ponderosa Laws). Isocupressic acid has been identified as an abortifacient component of the needles of ponderosa pine. Macrocarpa collected from the Palmerston North area contained 0.89% and 1.24% isocupressic acid, compared to 1.70% isocupressic acid in Ponderosa pine needles from Oregon in the United States as analysed by the USDA-ARS Poisonous Plant Research Laboratory. These findings support observations that macrocarpa causes abortion in late gestation cattle in New Zealand and suggest the causal agent is probably isocupressic acid.  相似文献   

8.
Consumption of Ponderosa pine needles by cows during late pregnancy results in the premature delivery of viable calves. Previous observations made at necropsy suggested that vascular insufficiency in the caruncular bed was associated with this induced parturition. The present studies used the perfused caruncular arterial bed of an isolated bovine placentome to determine whether blood plasma collected from cows fed pine needles contained a vasoactive factor(s). Changes in caruncular arterial tone (i.e., long-term changes in vessel diameter) and phasic contractility (i.e., transient reductions in vessel diameter) were evaluated. Tone was quantified as the pressure exerted against a constant intraluminal flow and as the force of contraction during K(+)-stimulated depolarization of membranes. Phenylephrine, an alpha 1-adrenergic agonist, was used to stimulate a phasic contractile response. Jugular blood was collected from beef cows fed pine needles (n = 4) or a control diet (n = 4), during the last 3 d of gestation, and plasma was used for two studies. In Study 1, placentomes were perfused with decreasing dilutions (1:150 to 1:40) of plasma pooled over the last 3 d of pregnancy from cows fed pine needle or control diets. Caruncular arterial perfusion pressures and responses to K+ progressively increased (P less than .05) with decreasing dilutions of plasma from cows fed pine needles, and responses to phenylephrine remained constant. Caruncular arterial perfusion pressures and responses to K+ and phenylephrine remained constant during perfusion of plasma from cows fed the control diet. In Study 2, the changes in vasoactivity of plasma (1:60 dilution) from cows fed pine needles was evaluated during the last 3 d of pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

9.
Four experiments were conducted to determine the effect of feeding dried pine needles (Pinus ponderosa; PN) on the abortion rate of ruminants. In Exp. 1, cattle were fed 5.4 kg of PN daily for 21 d starting at 116, 167, 215, or 254 d of pregnancy. The PN did not cause abortions when started at 116 d; thereafter, the percentage of cows that aborted increased linearly, and the interval to abortion decreased linearly (both P < .01); all cows fed PN beginning at 254 d aborted. In Exp. 2, cattle were fed .7, 1.4, or 2.7 kg of PN for 21 d or 2.7 kg for 1 or 3 d. Sheep and goats were fed .8 and .5 kg of PN, respectively, starting at 121 d of pregnancy. The PN induced some abortions in cattle when fed for 1 (11%) or 3 (30%) d, but the abortion rate was greater (P < .01) when the PN were fed for longer periods of time (80, 90, and 100% aborted in 19, 17, and 10 d for .7-, 1.4-, and 2.7-kg doses, respectively). No goats or sheep aborted in response to PN feeding. Pregnancy rates during the next breeding season for cows that aborted in response to the PN were slightly higher than rates for control cows (94 vs 87%). In Exp. 3, buffalo (Bison bison) and cattle were fed 2.25 kg of PN from the same collection. Abortions were induced in all buffalo and cattle that were fed PN.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

10.
Prenatal mortality is an important cause of production losses in the livestock industry. This study estimates the prevalences of abortion and stillbirth in a beef cattle system and determines the significance of some risk factors, in the tropics of Mexico. Data were obtained from a Zebu cattle herd and their crosses with Bos taurus breeds, in Yucatan, Mexico. The logit of the probability of an abortion or stillbirth was modeled using binary logistic regression. The risk factors tested were: year of abortion (or calving), season of abortion (or calving), parity number and dam breed group. The effect of twins on stillbirth was tested using Fisher exact test. Of the 4175 calvings studied 49 were abortions (1.17%). Significant factors in the logistic regression analysis for abortions were season of abortion and parity number. The risk of abortion was lower in the dry seasons compared to the rainy and windy seasons (P = 0.009). The risk of abortion was higher in second parity cows followed by the third and first parity cows, as compared to older cows (P = 0.015). Of the 4126 births, 87 were stillbirths (2.11%). Significant factors in the logistic regression analysis for stillbirth were year of calving (P = 0.0001) and parity number (P < 0.001). The risk of stillbirth in first parity cows was 2.6 times that of old cows. Of the total births, 15 were twins (0.36%) of which 7 were born dead calves. Herd owners must focus on the significant risk factors under their control to reduce the prevalence of prenatal mortality.  相似文献   

11.
Herd health records from 1983 to 1985 were analysed for a sample of 19 dairy farms on the Atherton Tableland in tropical north Queensland. Abortion and first service conception rates were calculated for each farm for each year. The association between abortion rate and stage of gestation at pregnancy diagnosis was investigated as well as the association between abortion rate and lactation status. There was a significant linear increase in abortion rate over the 3-year period, during which the mean rate was 7.3 +/- 2.1% (range 4.5% to 10.9%). There was also a significant variation in first conception rates during the same period, when the mean first service conception rate was 51.8% +/- 6.6% (range 42.4% to 65.8%). A significantly higher abortion rate was recorded in first lactation cows. Of 178 abortions in all lactation groups (1984), 20.3% were repeat abortions by the same cows. Of 163 abortions, a majority (80.4%) occurred during months 3 to 7 of gestation. No significant association was found between the timing of pregnancy diagnosis and occurrence of abortion.  相似文献   

12.
Needles of the Ponderosa pine (Pinus ponderosa) induce premature parturition in cattle when ingested during late pregnancy, especially during the third trimester. The closer to term, the more likely that pine needles will induce parturition. Experiments were designed to describe the clinical signs and behavior associated with ingestion of pine needles. Pine needles adversely affected only pregnant cows and did not seem to affect nonpregnant, cycling cows, sheep, goats, or rabbits. Premature parturition was more likely if cows ingested the needles after the 8th mo of pregnancy, if they ingested pine needles over a period of 3 d or more, and if cows ate a relatively large amount of pine needles (about 2.2 to 2.7 kg/d). A synthetic progesterone, melangesterol acetate, and a prostaglandin inhibitor (ketoprofen) seemed to be of some prophylactic benefit; however, further research is required to assess the practicality of the approach and the magnitude of the benefit. Ponderosa pine bark and new-growth branch tips, which seem to be more potent inducers of premature parturition, may be useful in the extraction and identification of the parturifacient component(s).  相似文献   

13.
Epidemiology of bovine abortions in Israeli dairy herds   总被引：1，自引：0，他引：1  
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14.
Twin pregnancies are classified into bilateral (one fetus in each uterine horn: 44%) and unilateral (both fetuses in the same uterine horn, right or left: 56%). The incidence of abortion during mid- to late gestation is approximately 1% in cows carrying bilateral twins and more than 40% in cows carrying unilateral twins. In this period, abortion seems most commonly associated with infectious agents. However, although this imbalanced abortion rate may imply that unilateral twin pregnancy is a non-infectious abortion factor, few available data can describe the cause of abortions in twin pregnancies. The current findings suggest that unilateral twin pregnancy is a non-infectious factor required for the etiological diagnosis of abortion in dairy herds.  相似文献   

15.
The seroprevalence of Neospora caninum infection was estimated from a sample of 889 cattle from 43 dairy herds in three counties in the Asturias region of Spain. The true prevalence of infection was estimated to be 30.6 per cent (95 per cent confidence interval (CI) 27.6 to 33.6). Seropositivity was associated with abortion during the previous year (odds ratio (OR)=3.31, P<0.001) and was slightly higher among purchased cattle (37.6 per cent), than among cattle raised on the farm (29.1 per cent) (P=0.078). Seropositive cows were more likely than seronegative cows to have had a seropositive dam (OR=2.3, P=0.011), suggesting that congenital transmission contributed to about 56 per cent of the infections. Herds with a true seroprevalence above 10 per cent had more dogs on the farm, than herds with a lower prevalence (P=0.032). The ORS relating abortion to seropositivity in individual herds ranged from 0.7 to 19, indicating that some herds experienced few abortions caused by N. caninum, while others experienced more abortions due to the organism. Overall, 38.7 per cent of the abortions were estimated to have been attributable to N. caninum.  相似文献   

16.
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17.
Three components of Ponderosa pine trees were administered via gavage to pregnant cows to determine their ability to induce premature parturition. When tips of branches, bark or needles were administered (2.7 kg/day) starting at 250 d of pregnancy, early parturition was induced in an average of 3.4, 5.0 and 9.1 d, respectively, compared to 31.8 d for water gavaged controls (P less than 0.01). Less pine material was required to induce parturition with tips and bark (9.4 and 11.2 kg/cow, respectively) than with needles (25.0 kg/cow P less than 0.05). Cows fed pine material retained fetal membranes longer after parturition; 13.0 d for needles, 10.5 d for bark and greater than 3.0 d for tips versus less than 0.5 d for controls (P less than 0.01). However, 2 of the cows fed tips died within 48 hours after parturition with fetal membranes intact and the other 2 cows fed tips became depressed, pyrexic and emaciated. They survived after extended veterinary care with antibiotic and fluid therapy. Administration of pine materials modified serum progesterone concentration profiles; there was significant elevation in progesterone 1-3 days after pine material was administered. Subsequently, pine material induced a premature decline in progesterone levels prior to parturition, which occurred more rapidly in cows fed bark and tips suggesting a dose response relationship. Pine material also modified serum cortisol concentration profiles; the main difference was a prolonged elevation in cows receiving tips. Branch tips and bark from Ponderosa pine are more potent in inducing parturition than needles.  相似文献   

18.
The serological status of Neospora was monitored in animals older than 6 months in a dairy herd with a 3-year history of prevalent N. caninum and N. caninum-associated abortions. The numbers of animals in the herd tested each year of the study period were 259, 222 and 231, respectively. A separate analysis was performed on the 122 animals persisting in the herd for the 3 years. The overall seroprevalence of N. caninum in the herd decreased from 31.7% in the first year to 24.8% in the second year and to 19.9% in the third year of the study, while the overall abortion rate decreased from 20.6% in the first year to 5.5% in the second year, and 9.9% in the third. These decreases occurred in response to control measures adopted from the second year onwards, such as culling Neospora-seropositive aborted animals and inseminating Neospora-seropositive dams with beef bull semen. Of the total number of abortions recorded in seropositive animals, 51% were repeat abortions that occurred in 36.8% of the animals with a previous history of abortion. The initial seroprevalence of Neospora in the 122 animals followed for the 3 years was 18%, increasing to 21.3% in the second and third years. Seroconversion only occurred in four animals during the second and third years of the study and abortion occurred only in seropositive individuals. Of the total number of abortions recorded in the 122 animals, 61.5% were repeat abortions that occurred in 26.7% of the animals with a previous history of abortion. These results indicate that Neospora seropositivity can be very stable through time and N. caninum infected cows can show a high rate of repeat abortions. The present data reinforce the idea that annual serological screening for Neospora can be an effective and rapid method of detecting N. caninum infection, such that control measures can be established at the farm level.  相似文献   

19.
Previous studies have shown that the use of beef bull semen significantly reduces the rate of abortions due to Neospora caninum in artificially inseminated (AI) seropositive dairy cows. In addition, certain beef breeds could be more resistant to N. caninum infection and abortion than others. The aim of the present study was to determine whether different crossbreed pregnancies, those derived from Limousin, Charolais, Piedmontese or Belgian Blue semen, carry different risks of abortion in Neospora-infected dairy cows. The effects of possible interactions between maternal levels of N. caninum antibodies and the different breed crosses were also evaluated. The study was performed on five commercial Holstein–Friesian dairy herds in Northeast Spain with previously confirmed diagnoses of N. caninum infection in aborted foetuses. The study population was comprised of 1115 pregnancies: 633 pregnancies recorded after AI using Holstein–Friesian semen from 18 bulls and 482 after AI using beef semen from 27 bulls (304 inseminations using semen from Limousin bulls, 191 from Belgian Blue bulls, 89 from Piedmontese bulls and 49 from Charolais bulls). Abortion rates were 32.2% (155/482) and 15.2% (96/633) for seropositive cows inseminated with Holstein–Friesian and beef breed semen, respectively. Logistic regression analysis revealed the herd and the interaction between maternal N. caninum antibody titre and the different crossbreeds as significant factors affecting the abortion rate. Lowest abortion rates, similar to that shown by seronegative animals in the analysed herds (3.2%, 239/7432), were observed in dams AI using Limousin semen that had low (<30 relative index (RI) units) N. caninum antibody titres (2.1% abortion, 3/145) and these cows were used as reference. Compared to the cows used as reference, cows with low N. caninum antibody titres (<30 RI units) showed a similar risk of abortion when inseminated with Piedmontese or Charolais bull semen, but higher risk of abortion when inseminated with Holstein (17.9 times) or Belgian Blue (7.2 times) bull semen. All cows with high N. caninum antibody titres (≥30 RI units) had a higher risk of abortion, ranging from 8.9 times (cows inseminated with Limousine semen) to 37.8 times (cows inseminated with Piedmontese semen), compared to the cows used as reference. In conclusion, different crossbreed pregnancies carried different abortion risks in Neospora-infected dairy cows. The use of beef bull semen dramatically reduced the risk of abortion in dairy cows, especially if Limousin breed semen was used. Moreover, this reduction was found to be dependent on the N. caninum antibody titre such that the lowest incidence of abortions was recorded in Limousin semen inseminated cows with low antibody titres. Insemination of Neospora-seropositive cows with beef bull semen could both reduce the risk of abortion and avoid breeding replacements for infected cattle.  相似文献   

20.
Neospora caninum is considered one of the major causes of abortion in cattle in most parts of the world. In this study, the role of N. caninum was investigated in groups of aborted cattle and dairy herds from the west of France. Good correlation was found between parasite DNA detection in fetuses and serologic statuses of dams. In groups with documented abortion status and no antibodies to other pathogens, 17-45% of aborted animals were seropositive for N. caninum, and significant relationship between prevalence of Neospora antibodies and frequency of abortions was found. Neospora-associated abortions were observed all the year round, with a peak in summer. Higher ratios of seropositive abortions were found before the 6th month of gestation. In 12 herds studied in the field, serologic prevalence ranged 6-47%. No difference in age was found between seropositive and seronegative cows. Results indicate that N. caninum is an important and stable cause of abortion in cattle in France.  相似文献   

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