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L J Burton

Publications and source records attributed to L J Burton.

10 recordsLinked to original sources
PubMed2000

Progesterone and follicular changes in postpartum noncyclic dairy cows after treatment with progesterone and estradiol or with progesterone, GnRH, PGF2alpha, and estradiol.

A previous study showed that noncyclic dairy cows treated with 10 microg of GnRH and a progesterone-releasing CIDR insert on Day 0, 25 mg of PGF2alpha and CIDR removal on Day 7, followed by 1 mg estradiol benzoate on Day 9 for those cows that still had not shown estrus (CGPE program) had higher conception rate (47% vs. 29%) than cows treated only with CIDR and estradiol benzoate as above (CE program). This study was to investigate the mechanisms by which the CGPE program improved conception rate compared with the CE program. Sixteen noncyclic Holstein-Friesian cows were randomly assigned to 2 groups balanced for the size and growth pattern of the dominant follicles, which were determined by ultrasonography over a 3-d period. One group received the above CGPE treatment, and the other group received the CE treatment. Follicular and luteal development were monitored by daily ultrasonography. Blood samples were collected daily from Day -2 to Day 11, and thereafter milk samples were collected thrice weekly for a further 24 d. Blood and milk samples were analyzed for progesterone. The GnRH treatment induced ovulation in 7 of 8 cows, resulting in elevated (P<0.05) progesterone concentrations between Days 4 and 7 for cows in the CGPE group. All induced CL underwent luteolysis by 24 h after PGF2alpha treatment. Within 5 d of CIDR removal, 7 of 8 cows in both the CE and CGPE groups ovulated. The interval from emergence of the ovulatory follicle to ovulation was similar (P=0.32) but less (P<0.05) variable for the CGPE group (9.0+/-0.3 d) compared with the CE group (10.3+/-1.2 d). Progesterone concentration in milk samples was similar between the two groups up to 10 d after ovulation. In summary, the GnRH treatment induced ovulation or turnover of dominant follicles, induced a synchronized initiation of a new follicular wave, and increased the progesterone concentration from 4 d after treatment. These could be the reasons for the increased conception rate of cows treated with the CGPE program.

Animals↗
PubMed2000

Treatment of noncyclic lactating dairy cows with progesterone and estradiol or with progesterone, GnRH, prostaglandin F2 alpha, and estradiol.

The efficacy of two programs for treating noncyclic cows was compared. In trial 1, 478 cows in five herds were randomly divided into two groups. Cows in one group (C group) were treated with an intravaginal progesterone device for 8 d followed in 48 h by 1 mg of estradiol benzoate to cows that had not been detected in estrus since device removal. Those in the other group (CGP group) were treated with progesterone and estradiol as for the C group plus 10 micrograms of a GnRH agonist (buserelin) at device insertion and 25 mg of PGF2 alpha 7 d after device insertion. In trial 2 with 729 cows in nine herds, the treatments were similar to those in trial 1 except that the duration of progesterone treatment was 7 d. No significant difference was found between trials and results from both trials were combined. Compared with C group cows, CGP group cows had a greater estrous response rate (93.2 vs. 89.1%), a greater conception rate to first artificial insemination (AI, 47.1 vs. 29.4%), marginally lower conception rate to second AI (52.9 vs. 59.7%), lower nonpregnancy rate (8.3 vs. 11.1%), and shorter intervals from the start of breeding to conception by AI (9.8 vs. 15.3 d) or by AI or natural mating (21.6 vs. 26.3 d). The treatment protocol used for the CGP group achieved better reproductive performance than that used for the C group.

Animals↗
PubMed2000

Estrus synchronization of lactating dairy cows with GnRH, progesterone, and prostaglandin F2 alpha.

The reproductive performance of synchronized cows was compared with that of nonsynchronized cows. In trial 1, cyclic cows in five seasonal herds were randomly divided into two groups. Cows in one group (n = 515) were treated with a GnRH agonist and an intravaginal progesterone device, followed in 7 d by a PGF2 alpha injection, and the device was removed 1 d after PGF2 alpha. Cows in the other group (n = 512) did not receive any treatment and acted as control. In trial 2, the treatments were similar to those used in trial 1 except that the progesterone device was removed at the time of PGF2 alpha injection (synchronized: n = 516; control: n = 512). The estrus synchronization rate was 92.8% in trial 1 and 92.2% in trial 2. Conception rate to first artificial insemination (AI) was lower for synchronized cows than for control cows in trial 1 (56.5 vs. 62.7%), but similar in trial 2 (64.6 vs. 63.3%). Across both trials, the pregnancy rate during the AI breeding period was greater for the synchronized cows (85.6%) than for the control cows (81.2%). The synchronization treatment reduced the interval from start of the breeding season to conception for cows conceiving by AI (8.9 vs. 14.8 d) or by AI or natural mating (14.1 vs. 21.6 d). The synchronization protocol used in trial 2 achieved better conception rate than that used in trial 1, but the precision of estrus was less in trial 2 than in trial 1.

Administration, Intravaginal↗
PubMed1999

Vancomycin use.

Explore the source record for details and available documents.

Adolescent↗
PubMed1999

Reproductive performance of dairy heifers after estrus synchronization and fixed-time artificial insemination.

The reproductive performance of heifers after estrus synchronization and fixed-time AI was compared with nonsynchronized heifers in 25 spring-calving herds. Within herds, heifers were divided into a synchronized (n = 1123) or a control (n = 1125) group. Heifers in the synchronized group were treated with a combination of progesterone, estradiol benzoate, and PGF2 alpha and were inseminated between 50 and 54 h after progesterone treatment. Returns to first service were resynchronized with progesterone treatment between 16 and 21 d after the fixed-time AI. The conception rate of synchronized heifers to the fixed-time AI (53.2%) and to AI after resynchronization (53.1%) was lower than that of control heifers (63.7%). However, pregnancy rate in the first 24 d was higher for the synchronized group (72.4%) than for the control group (67.8%). More control heifers (5.7%) than synchronized heifers (4.0%) failed to conceive. The interval from start of breeding to calving was earlier for synchronized (296.2 d) than for control (299.5 d) heifers. Jersey heifers had lower reproductive performance than did Friesian heifers. Synchronized heifers gave birth to more female calves (53.8%) than did control heifers (45.7%). It is concluded that the above program can be used successfully to synchronize dairy heifers for fixed-time AI.

Animals↗
PubMed1998

Synchronization of estrus with PGF2 alpha administered 18 days after a progesterone treatment in lactating dairy cows.

In a previous study we showed that estrus synchronization with 2 treatments of PGF2 alpha 13 d apart reduced conception rate at the synchronized estrus and that this reduction occurred mainly in cows in the early luteal phase at the second PGF2 alpha treatment. The objective of the present study was to determine the efficacy of a synchronization regimen in which PGF2 alpha was administered during the mid- to late-luteal phase to cows that had previously been synchronized with progesterone. Spring-calving cows from 6 dairy herds were used in this study. On Day -32 (Day 1 = the start of the breeding season), cows that had calved 2 or more weeks ago were randomly assigned to a synchronization (S, n = 732) or control (C, n = 731) group. Cows in Group S were treated with an intravaginal progesterone device (CIDR) for 12 d from Day -32 to Day -20, while those in Group C were left untreated. Similar percentages of cows in Group S (80.6%) and C (82.9%) had cycled by Day -7. The CIDR treatment synchronized the onset of estrus, resulting in 92.9% of cows in estrus being detected within 7 d after CIDR removal. Cows in Group S that had cycled by Day -7 were treated with PGF2 alpha (25 mg, i.m., Lutalyse) on Day -2. Cows in both groups that were anestrous on Day -7 were treated with a combination of progesterone and estradiol benzoate (EB) to induce estrus and ovulation (CIDR and a 10 mg EB capsule on Day -7, CIDR removal on Day -2, and injection of 1 mg EB 48 h after CIDR removal). The PGF2 alpha treatment synchronized the onset of estrus in 87.5% of the cows. Group S and C cows had similar conception rates to first (61.0 vs 58.3%) and second (58.4 vs 60.9%) AI; similar pregnancy rates over the AI period (82.8 vs 79.2%) and over the whole breeding season (91.9 vs 90.6%); and required a similar number of services per pregnancy to AI (1.7 vs 1.8). The interval from the start of the breeding season to conception for cows conceiving to AI or to combined AI and natural mating was shorter (P < 0.001) by 5.7 and 6.2 d, respectively, for the Group S cows. It is concluded that the treatment regimen tested in the present study achieved satisfactory estrus synchronization, had no detrimental effect on fertility at the synchronized estrus, and shortened the interval from start of the breeding season to conception.

Administration, Intravaginal↗
PubMed1998

Pseudoparalysis of the lower extremity in an infant.

We describe a case of septic arthritis of the knee in an afebrile, well-appearing four-month-old female. She had been evaluated previously for lower extremity disuse attributed to antecedent trauma. Her physical examination was remarkable only for limitation of extension of the affected leg at the knee. Emergency physicians should understand the physical examination findings suggesting joint effusion and the need to consider osteomyelitis/septic arthritis in children less than one year of age with pseudoparalysis.

Arthritis, Infectious↗
PubMed1998

Estrus detection using radiotelemetry or visual observation and tail painting for dairy cows on pasture.

The efficiency and accuracy of estrus detection using HeatWatch (DDx Inc., Denver, CO) or visual observation were compared in an autumn-calving Friesian herd (n = 48 per group) and a spring-calving Jersey herd (n = 50 per group) grazing on pasture. Cows in the group monitored by the HeatWatch system were fitted with a pressure-sensitive transmitter that signaled mounting activities associated with estrus. Visual observation was carried out for about 20 min before the morning and afternoon milkings and was aided by a strip of paint applied over the tailhead. Ovarian cyclicity was monitored with progesterone concentrations in milk samples collected twice a week. The efficiency and accuracy of estrus detection were, respectively, 98.4 and 97.6% for visual observation and 91.7 and 100% for HeatWatch detection. Autumn-calving herds differed from spring-calving herds in duration of estrus (9.7 vs. 7.3 h), number of mounts (13.6 vs. 8.5), total duration of mounts (36.8 vs. 19.9 s), and mean duration of a mount (2.6 vs. 2.3 s). There was no significant variation in the distribution of the time of onset of estrus or mounting activities at different hours of the day. Conception rate was similar for AI after estrus detection with HeatWatch (65.8%) or after visual observation (65.0%). The highest conception rate was obtained when AI was carried out between 12 and 18 h after the first mount. Both the HeatWatch system and visual observation plus tail painting can be used for estrus detection of dairy cows on pasture.

Animals↗
PubMed1997

Headache etiology in a pediatric emergency department.

BACKGROUND: Headache may be the presenting complaint of serious diagnoses such as meningitis, brain tumor, or shunt malfunction, yet no previous studies have examined the spectrum of diagnoses for the pediatric emergency department (ED) population with a chief complaint of headache. METHODS: In 1993, 53,988 visits were made to the ED of an urban children's hospital. Six hundred ninety-six patients (1.3%) had a chief complaint of headache. Half of these visits, distributed randomly throughout the year, were chosen for review; total sample size was 288. RESULTS: Patient age ranged from two to 18 years (2-5 years, 24.3%; 6-12 years, 57.6%; 13-18 years, 18.1%). The spectrum of ED diagnoses included viral illness (39.2%), sinusitis (16.0%), migraine (15.6%), post-traumatic headache (6.6%), streptococcal pharyngitis (4.9%), and tension headache (4.5%). No cases of brain tumor or bacterial meningitis were identified at the time of ED visit. The only serious neurologic conditions diagnosed were 15 cases of viral meningitis (5.2%), one shunt malfunction, one newly diagnosed hydrocephalus, one Burkitt's lymphoma patient with newly diagnosed CNS infiltration, and one punctate hemorrhage post head trauma. Two thirds of patients had radiologic and/or laboratory tests. Positive findings were as follows: 45.6% of sinus radiographs, 16.3% of rapid streptococcal antigen tests, 60.9% of lumbar punctures, and 19.0% of brain imaging studies. The frequency of serious and nonserious conditions as a cause of headache was compared to data from general EDs. CONCLUSION: Serious conditions presenting with the chief complaint of headache in the pediatric ED were not common in our population. The most frequent diagnoses in our review were viral illness, sinusitis, and migraine, in contrast to adult studies in which tension headache and migraine were most common. Only 6.6% of patients had serious neurologic diagnoses, which is in the range reported for general EDs. Of the serious conditions in our study, 80% were viral meningitis.

Adolescent↗