Hysterectomy during the luteal period in dogs chronically treated with bromocriptine     

A C Okkens  M M Bevers  S J Dieleman  A H Willemse 《The Veterinary quarterly》1989,11(4):254-256

To determine whether prolactin has luteolytic properties during the first part of the luteal period, hysterectomy was performed in four dogs, in which prolactin had been chronically suppressed by bromocriptine administration. The concentration of progesterone in the peripheral blood decreased upon hysterectomy during the first part of the luteal phase and regained normal values after about seven days. The progesterone patterns during the perisurgical period in these dogs were similar to those patterns observed in dogs hysterectomised without bromocriptine treatment. It is concluded therefore that, in the dog, luteolytic properties can not be attributed to prolactin.  相似文献   

Key Factors Affecting Reproductive Success of Thoroughbred Mares and Stallions on a Commercial Stud Farm          下载免费PDF全文

EA Lane  MLJ Bijnen  M Osborne  SJ More  ISF Henderson  P Duffy  MA Crowe 《Reproduction in domestic animals》2016,51(2):181-187

To evaluate factors contributing to fertility of thoroughbred mares, data from 3743 oestrous periods of 2385 mares were collected on a large thoroughbred farm in Ireland. Fourteen stallions (mean age 8.3 years; range 4–15 years) had bred 2385 mares (mean age 9.4 years; range 3–24 years). Maiden mares accounted for 12%, mares with a foal at foot for 64%, and barren, slipped or rested mares for 24% of the total. The mean pregnancy rate per cycle was 67.8% (68.6% in year 1 and 66.9% in year 2). Backward stepwise multivariable logistic regression analysis was utilized to develop two models to evaluate mare factors, including mare age, reproductive status, month of foaling, dystocia, month of cover, foal heat, cycle number, treatments, walk‐in status and stallion factors including stallion identity, stallion age, shuttle status, time elapsed between covers and high stallion usage on the per cycle pregnancy rate and pregnancy loss. Old age (p < 0.001) and cover within 20 days post‐partum (p < 0.003) were associated with lowered pregnancy rates. High mare age (p < 0.05) and barren, slipped or rested reproductive status (p = 0.05) increased the likelihood of pregnancy loss. Uterine inflammation or infection, if appropriately treated, did not affect fertility. Only high usage of stallions (used more than 21 times in previous week) was associated with lowered (p = 0.009) pregnancy rates. However, shuttle stallions were more likely to have increased (p = 0.035) pregnancy survival, perhaps reflecting a bias in stallion selection. In conclusion, mare age exerted the greatest influence on fertility; nonetheless, thoroughbreds can be effectively managed to achieve high reproductive performance in a commercial setting.  相似文献   

The relation between ultrasonographic observations in the oviduct and plasma progesterone, luteinizing hormone and estradiol during the egg laying cycle in ostriches     

Bronneberg RG  Taverne MA  Dieleman SJ  Decuypere E  Bruggeman V  Vernooij JC  Stegeman JA 《Domestic animal endocrinology》2007,32(1):15-28

In this study we investigated the temporal relationship between ovulation, egg formation, oviposition and the changes in plasma concentrations of progesterone, luteinizing hormone and estradiol-17beta during the egg laying cycle in farmed ostriches. In 10 egg-producing birds, transcutaneous ultrasound scanning was performed at 3h intervals and blood sampling at hourly intervals during a period of at least 48h (one egg laying cycle). In hens (n=8) that ovulated during the observational period, the ovulated egg was first detected 2h after oviposition; thus, ovulation occurred shortly after oviposition in all birds. During the period between two consecutive ovipositions, the developing egg remained for 9h in the proximal part (infundibulum, magnum or isthmus) and for 39h in the distal part of the oviduct (uterus). In ovulating hens, plasma progesterone concentrations showed a characteristic and consistent profile: from basal levels of around 0.1ng/ml concentrations started to increase 12h before oviposition, reached an average maximum of 3.5ng/ml at 3h before oviposition and returned to basal levels 3h and 30min after oviposition. Changes in plasma luteinizing hormone and estradiol-17beta concentrations showed comparable patterns of elevation and decline relative to the timing of oviposition and ovulation. However, variation in their individual basal concentrations was generally larger and peak values were less conspicuous than those of progesterone. In non-ovulating hens (n=2) neither progesterone, nor luteinizing hormone nor estradiol-17beta showed elevations to peak concentrations before oviposition. These data demonstrate that during the egg laying cycle of ostriches, events such as ovulation, egg development and oviposition evolve according to a rather strict time schedule, and that progesterone, luteinizing hormone and estradiol-17beta reach peak concentrations shortly before ovulation. Additionally, our findings also show that on-farm ultrasound scanning is a useful technique to discriminate between ovulating and non-ovulating hens.  相似文献   

Adenohypophyseal function in bitches treated with medroxyprogesterone acetate     

Beijerink NJ  Bhatti SF  Okkens AC  Dieleman SJ  Mol JA  Duchateau L  Van Ham LM  Kooistra HS 《Domestic animal endocrinology》2007,32(2):63-78

The aim of this study was to investigate the effects of treatment with medroxyprogesterone acetate (MPA) on canine adenohypophyseal function. Five Beagle bitches were treated with MPA (10mg/kg, every 4 weeks) and their adenohypophyseal function was assessed in a combined adenohypophyseal function test. Four hypophysiotropic hormones (CRH, GHRH, GnRH, and TRH) were administered before and 2, 5, 8, and 11 months after the start of MPA treatment, and blood samples for determination of the plasma concentrations of ACTH, cortisol, GH, IGF-1, LH, FSH, prolactin, alpha-MSH, and TSH were collected at -15, 0, 5, 10, 20, 30, and 45 min after suprapituitary stimulation. MPA successfully prevented the occurrence of estrus, ovulation, and a subsequent luteal phase. MPA treatment did not affect basal and GnRH-induced plasma LH concentrations. The basal plasma FSH concentration was significantly higher at 2 months after the start of MPA treatment than before or at 5, 8, and 11 months after the start of treatment. The maximal FSH increment and the AUC for FSH after suprapituitary stimulation were significantly higher before treatment than at 5, 8, and 11 months of MPA treatment. Differences in mean basal plasma GH concentrations before and during treatment were not significant, but MPA treatment resulted in significantly elevated basal plasma IGF-1 concentrations at 8 and 11 months. MPA treatment did not affect basal and stimulated plasma ACTH concentrations, with the exception of a decreased AUC for ACTH at 11 months. In contrast, the maximal cortisol increment and the AUC for cortisol after suprapituitary stimulation were significantly lower during MPA treatment than prior to treatment. MPA treatment did not affect basal plasma concentrations of prolactin, TSH, and alpha-MSH, with the exception of slightly increased basal plasma TSH concentrations at 8 months of treatment. MPA treatment did not affect TRH-induced plasma concentrations of prolactin and TSH. In conclusion, the effects of chronic MPA treatment on adenohypophyseal function included increased FSH secretion, unaffected LH secretion, activation of the mammary GH-induced IGF-I secretion, slightly activated TSH secretion, suppression of the hypothalamic-pituitary-adrenocortical axis, and unaffected secretion of prolactin and alpha-MSH.  相似文献   

The effects of vaccination of Merino ewes with an attenuated Australian bluetongue virus serotype 23 at different stages of gestation   总被引：1，自引：0，他引：1  

M. FLANAGAN  SJ JOHNSON 《Australian veterinary journal》1995,72(12):455-457

SUMMARY A cell culture attenuated Australian bluetongue virus serotype 23 (BLU23) prototype vaccine was assessed for its effects on pregnant Merino sheep. Seventy-six ewes were vaccinated at 5 different stages of gestation, and the failure to lamb at term was as follows: 35 to 43 days of gestation, 20/36 (56%); 57 to 64 days of gestation, 3/10 (30%); 81 to 88 days of gestation, 3/10 (30%); 109 to 116 days of gestation, 0/10 (0%); 130 to 137 days of gestation, 0/10 (0%). Of 30 ewes vaccinated with a cell culture supernatant fluid control between 35 and 43 days of gestation, 6.7% (2/30) failed to lamb at term. Two ewes vaccinated with BLU23 vaccine between 35 and 43 days of gestation had lambs with hydranencephaly. All other lambs born were clinically normal. Three ewes vaccinated with BLU23 aborted. Two of these were vaccinated between 35 and 43 days of gestation, the 3rd between 81 and 88 days of gestation. Five lambs were born with BLU group antibody. Four of these were from ewes vaccinated between 35 and 43 days of gestation, and 2 of these had hydranencephaly. The fifth was from a ewe vaccinated between 57 and 64 days of gestation. The vaccine did not produce disease in adult sheep, but was a potent cause of early foetal death and to a much lesser extent foetal malformation.  相似文献   

Validation of a new method of visual oestrus detection on the farm     

Heres L  Dieleman SJ  van Eerdenburg FJ 《The Veterinary quarterly》2000,22(1):50-55

Since visual observation is the most commonly used way of detecting oestrus and is supposed to be as effective as detection with technical devices, we evaluated a recently developed oestrus detection scoring system in daily dairy practice. In this scoring system nine signs of oestrus are scored with points, ranging 3 to 100. Twenty-one dairy farmers used the scoring system during a period of 3 weeks. All cows that were more than 30 days post partum and not confirmed pregnant were monitored, using the scoring system, by the herd owners. Oestrus was confirmed by measuring progesterone concentrations in milk. With the scoring system a detection rate of 47% was achieved. This was lower than expected, because in an earlier control period, the detection rate was 64%. We concluded that this new method might be too complicated to introduce to normal herd management, because in daily practice it is too demanding to watch cows twice a day for 30 minutes, especially if the cows show only vague and infrequent symptoms of oestrus. It also appeared to be too complicated to watch the herd at the most appropriate time. However, if the scoring system is included in the daily routine, meaning that farmers are trained to watch for other symptoms than standing heat only and are able to recognize their different values, it can be a valuable aid to oestrus detection.  相似文献   

Interacting effects of temperature integration and light intensity on growth and development of single-stemmed cut rose plants     

J.A. Dieleman  E. Meinen 《Scientia Horticulturae》2007

Energy conservation in horticulture can be achieved by allowing temperatures to fluctuate within predefined bandwidths instead of using rigid set points for heating and ventilation. In temperature integration, plants are supposed to compensate effects of temporarily deviations of the average temperature some time later by deviations in the opposite direction. However, little is still known on the effects of integration periods exceeding 1 day. In this study, effects of temperature integration on growth and development of single-stemmed cut rose plants were determined. Pruned rose shoots were placed in climate chambers in which light levels switched daily (2 days integration period) or weekly (14 days integration period) from high light intensity (300 μmol m⁻² s⁻¹) to low light (150 μmol m⁻² s⁻¹). Temperatures were kept continuously at 20 °C (control) or changed with the light intensity (phase, high temperature at high light intensity, low temperature at low light intensity) or changed opposite to the light intensity (counter phase). Bandwidths of temperature integration were 0, 6 or 10 °C. Under these conditions, buds grew out to harvestable shoots in approximately 45 days. At both integration periods, shoot length was significantly reduced with increasing bandwidths of temperature integration. Shoot dry weights were reduced when a bandwidth of 10 °C was applied. At both integration periods, rates of photosynthesis were primarily determined by light intensity. However, in the counter phase treatments, photosynthesis rate at high light and low temperature was reduced compared to the high light condition of the control. Under these conditions, starch content increased to approximately 10%, suggesting a feedback inhibition of the rate of photosynthesis. However, this did not (yet) affect plant growth or development.  相似文献   

Gram-negative Mastitis in Early Lactation May Interfere with Ovarian and Certain Endocrine Functions and Metabolism in Dairy Cows   总被引：1，自引：0，他引：1  

G Huszenicza  S Jánosi  M Kulcsár  P Kóródi  SJ Dieleman  J Bartyik  P Rudas  P Ribiczei-Szabó 《Reproduction in domestic animals》1998,33(3-4):147-153

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Breeding sugar beets with globe-shaped roots: selection and agronomical performance     

M. Mesken  J. Dieleman 《Euphytica》1988,39(3):37-44

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Interactions between plant and aphid genotypes in resistance of lettuce to Myzus persicae and Macrosiphum euphorbiae     

K. Reinink  F. L. Dieleman  J. Jansen  A. M. Montenarie 《Euphytica》1989,43(3):215-222

Summary Six lettuce lines, representing two types of resistance to the green peach aphid, Myzus persicae, and a control line with high susceptibility to M. persicae were tested for resistance to six different clones of Myzus persicae and two clones of the potato aphid, Macrosiphum euphorbiae.The clones of M. persicae showed very different levels of aggressiveness on lettuce: two had a high level of reproduction, two had an intermediate level and two were poorly adapted to lettuce as a host. Differences between lettuce lines in aphid reproduction increased with increasing aggressiveness of the aphid clone, which means that aggressive clones are most effective for selection purposes. No evidence was found for clone-specific plant genotype reactions, meaning that lines resistant to one clone will also be resistant to other clones of M. persicae, allthough not neccessarily at the same level. The lettuce lines selected for partial resistance to the aggressive clone WMp1 were completely or almost completely resistant to less aggresive clones.No differences in level of reproduction were found between the two clones of M. euphorbiae and no relation was observed between resistance to M. persicae and M. euphorbiae, indicating the species-specific character of resistance to leaf aphids in lettuce.  相似文献