[Comparison of two models of a treatment area with respect to treatment times in critically ill patients : A pilot study]. / Vergleich zweier Modelle eines Behandlungsplatzes im Hinblick auf die Versorgungszeiten kritischer Patienten : Eine Pilotstudie.

BACKGROUND: In the case of a mass casualty incident an advanced medical post (AMP) plays a central role in the medical care by ambulance service and civil protection units. Besides the traditional organization with one triage category per medical services tent, it can also be structured in a mixed form (i.e. a defined number of patients with different triage categories are assigned to each medical services tent). To date it remains unclear which organization format is better in order to rapidly evacuate those patients with the highest priority. METHODS: The Medical Task Force of Lower Franconia treated 50 identical and standardized training patients including 18 triage category red/emergency (36%), 12 triage category yellow/urgent (24%), 18 triage category green/non-urgent (36%) and 2 triage category black/dead (4%) in the course of a scheduled field exercise within two consecutive training sessions (first session: classical structure, second session: mixed structure). The training patients were represented by a dynamic patient simulation, whereby simulation cards showed injury patterns and the external appearance of the patients at a defined point which required certain interventions. The patients' conditions changed when these measures were accomplished or neglected. The length of stay of the patients with the triage category red/emergency at the AMP (start of triage to start evacuation) as well as the overall number of evacuated patients were collated and compared. RESULTS: Out of 18 patients with the triage category red/emergency, 13 patients in each session were evacuated in one pass. During the first session the mean evacuation time at the AMP was 25 min and during the second session the mean evacuation time was 18 min. After the end of the 90 min of exercise time in the first session 14 non-critical patients (triage categories yellow/urgent and green/non-urgent, n = 30) were still left at the AMP (16 evacuated) and in the second session 12 (18 evacuated). CONCLUSION: Depending on the mission requirements the mixed form of AMP organization can provide several advantages. In addition to rapid operational readiness and high flexibility the patient distribution by triage category could be processed better and the evacuation time of critical patients could be shortened.

Lameness detection via leg-mounted accelerometers on dairy cows on four commercial farms.

Lameness in dairy herds is traditionally detected by visual inspection, which is time-consuming and subjective. Compared with healthy cows, lame cows often spend longer time lying down, walk less and change behaviour around feeding time. Accelerometers measuring cow leg activity may assist farmers in detecting lame cows. On four commercial farms, accelerometer data were derived from hind leg-mounted accelerometers on 348 Holstein cows, 53 of them during two lactations. The cows were milked twice daily and had no access to pasture. During a lactation, locomotion score (LS) was assessed on average 2.4 times (s.d. 1.3). Based on daily lying duration, standing duration, walking duration, total number of steps, step frequency, motion index (MI, i.e. total acceleration) for lying, standing and walking, eight accelerometer means and their corresponding coefficient of variation (CV) were calculated for each week immediately before an LS. A principal component analysis was performed to evaluate the relationship between the variables. The effects of LS and farm on the principal components (PC) and on the variables were analysed in a mixed model. The first four PC accounted for 27%, 18%, 12% and 10% of the total variation, respectively. PC1 corresponded to Activity variability due to heavy loading by five CV variables related to standing and walking. PC2 corresponded to Activity level due to heavy loading by MI walking, MI standing and walking duration. PC3 corresponded to Recumbency due to heavy loading by four variables related to lying. PC4 corresponded mainly to Stepping due to heavy loading by step frequency. Activity variability at LS4 was significantly higher than at the lower LS levels. Activity level was significantly higher at LS1 than at LS2, which was significantly higher than at LS4. Recumbency was unaffected by LS. Stepping at LS1 and LS2 was significantly higher than at LS3 and LS4. Activity level was significantly lower on farm 3 compared with farms 1 and 2. Stepping was significantly lower on farms 1 and 3 compared with farms 2 and 4. MI standing indicated increased restlessness while standing when cows increased from LS3 to LS4. Lying duration was only increased in lame cows. In conclusion, Activity level differed already between LS1 and LS2, thus detecting early signs of lameness, particularly through contributions from walking duration and MI walking. Lameness detection models including walking duration, MI walking and MI standing seem worthy of further investigation.

Comparison of Holstein-Friesian and Norwegian Red dairy cattle for estrus length and estrous signs.

This study addressed the effect of breed on estrus length and estrous behavior by observing 20 Holstein-Friesian (HF) and 20 Norwegian Red (NRF) cows on an outdoor wood-chip pad through 1 estrous cycle (22d). Detailed behavioral data were collected by continuous (24 h) video monitoring of all cows. Accurate estimation of duration of estrous periods, behavioral signs (sum per period and counts per hour), and duration and number of sexually active groups were reported through all stages of mount estrus (prestand, standing estrus, and poststand). These dependent variables were analyzed with a basic statistical model that included fixed effects for breed and lactation group. Other independent variables (milk yield, body condition score, and number of cows in standing estrus) were added to the basic model one by one and included in an expanded model if they had an effect on the respective dependent variables. Estrus duration was considerably shorter in HF compared with NRF cows for all the major periods: mount estrus (11.2 ± 3.0 vs. 21.3 ± 2.7 h), standing estrus (7.1 ± 1.4 vs. 11.7 ± 1.3 h), mounting period (6.9 ± 2.7 vs. 18.2 ± 2.4 h), and mounted period (9.2 ± 2.8 vs. 17.5 ± 2.6 h). Additionally, the NRF cows spent more time in sexually active groups (36.1 ± 4.0 vs. 17.6 ± 4.8%) during standing estrus compared with HF cows. The NRF cows participated in a greater number of sexually active groups (9.6 ± 1.3 vs. 5.5 ± 1.3) with longer average duration (0.42 ± 0.04 vs. 0.20 ± 0.04 h) and continued to be more active in these groups through late stages of estrus (poststand) compared with the HF breed. Mounting activity differed between breeds as NRF mounted more times in total (46.3 ± 6.2 vs. 18.1 ± 6.3) and per hour (2.6 ± 0.4 vs. 1.5 ± 0.5) during mount estrus. In addition, NRF tended to express the primary estrous sign, standing when mounted, more often during standing estrus (32.4 ± 5.0 vs. 18.5 ± 5.2). The HF initiated more unsuccessful mounts (1.6 ± 0.3 vs. 0.6 ± 0.3) per hour than did NRF during mount estrus. A significant effect of milk yield was demonstrated only on this behavior. For other estrous signs, HF cows initiated chase-up (2.0 ± 0.5 vs. 0.5 ± 0.4) and anogenital sniff (3.7 ± 0.6 vs. 2.0 ± 0.5) more frequently (counts per hour), whereas NRF expressed more total head butt behavior (32.3 ± 4.7 vs. 14.2 ± 4.8) during mount estrus. Body condition score had a significant effect on receptive behavior. Measures of estrus duration, sexually active group activity, and behavior related to estrus should be subjected to larger studies for improved heat detection and possible implementation in breeding programs.

Reproduction Symposium: does grazing on biosolids-treated pasture pose a pathophysiological risk associated with increased exposure to endocrine disrupting compounds?

Biosolids (processed human sewage sludge), which contain low individual concentrations of an array of contaminants including heavy metals and organic pollutants such as polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), and polychlorinated dibenzodioxins/polychlorinated dibenzofurans known to cause physiological disturbances, are increasingly being used as an agricultural fertilizer. This could pose a health threat to both humans and domestic and wild animal species. This review summarizes results of a unique model, used to determine the effects of exposure to mixtures of environmentally relevant concentrations of pollutants, in sheep grazed on biosolids-treated pastures. Pasture treatment results in nonsignificant increases in environmental chemical (EC) concentrations in soil. Whereas EC concentrations were increased in some tissues of both ewes and their fetuses, concentrations were low and variable and deemed to pose little risk to consumer health. Investigation of the effects of gestational EC exposure on fetal development has highlighted a number of issues. The results indicate that gestational EC exposure can adversely affect gonadal development (males and females) and that these effects can impact testicular morphology, ovarian follicle numbers and health, and the transcriptome and proteome in adult animals. In addition, EC exposure can be associated with altered expression of GnRH, GnRH receptors, galanin receptors, and kisspeptin mRNA within the hypothalamus and pituitary gland, gonadotroph populations within the pituitary gland, and regional aberrations in thyroid morphology. In most cases, these anatomical and functional differences do not result in altered peripheral hormone concentrations or reproductive function (e.g., lambing rate), indicating physiological compensation under the conditions tested. Physiological compensation is also suggested from studies that indicate that EC effects may be greater when exposure occurs either before or during gestation compared with EC exposure throughout life. With regard to human and animal health, this body of work questions the concept of safe individual concentration of EC when EC exposure typically occurs as complex mixtures. It suggests that developmental EC exposure may affect many different physiological systems, with some sex-specific differences in EC sensitivity, and that EC effects may be masked under favorable physiological conditions.

Sexually active groups in cattle-a novel estrus sign.

The current study presents a novel objective measure for characterizing sexually active groups (SAG 3-5) and relates this measure to other behaviors of lactating Holstein-Friesian cows. Cows in SAG 3-5 were required to participate in a minimum of 1 estrus behavior per 5min while staying within 3m (2 cow lengths) of its partner(s) for a minimum of 5min. Twenty Holstein-Friesian cows were video-monitored continuously through 1 complete estrous cycle (22d). Standing behavior, SAG 3-5, secondary estrus signs (SEC), and other social and agonistic behaviors were recorded continuously. The period of mounting estrus (MTE) was divided into the 3 parts: prestand, standing estrus (STE), and poststand. The mean durations of MTE, prestand, STE, and poststand period were 12.9±1.84, 4.0±1.93, 7.1±1.44, and 1.8±0.57h (n=13). The fractions of time spent in SAG 3-5 during MTE, prestand, STE, and poststand period were 13, 8, 19, and 1% (n=11). During MTE, cows participated, on average, in 5.8±1.24 SAG 3-5 and initiated 9.5±2.99 mounts, with mean durations of 0.25±0.03h and 4.00±0.36s, respectively. The novel measure SAG 3-5 was a sign of long duration not confined only to groups of STE cows. On one day when no cows were in estrus and during the periods 4 to 24h before and after MTE, no SAG 3-5 behaviors were observed. Luteal-phase cows participated in SAG 3-5 only when the partner was a single cow in estrus. The time spent in SAG 3-5 increased between 1 and 3h before MTE and the prestand period (3 vs. 8%) and reached a peak level during STE. From STE to poststand, time spent in SAG 3-5 decreased considerably (19 vs. 1%). The observed decrease in nonmutual agonistic behaviors 4 to 24h before MTE is suggested as an early sign of pre-estrus. Changes in SAG 3-5, agonistic behaviors, and SEC are suggested as indicators of the specific stages of MTE. Increased SEC initiated and SAG 3-5 were indicators of late pre-estrus and early estrus (prestand). Peak levels of SAG 3-5, SEC, and social agonistic behaviors were indicators of STE. A sudden decrease in behaviors, preceded by frequent interactions, was indicative of late estrus (poststand). On the basis of the findings reported here, we propose that SAG 3-5, as well as proceptive and receptive patterns of SEC and agonistic behaviors, be included in estrus detection protocols. Updated knowledge of these behavioral interactions may assist when determining the stage of estrus and the optimal time to breed dairy cows.

Behavior of lactating Holstein-Friesian cows during spontaneous cycles of estrus.

The objectives of the present study were to describe, in detail, behavior associated with standing estrus (STE) in lactating dairy cows and behavioral changes during complete estrous cycles. Estrus signs were monitored by continuous video recording of 20 Holstein-Friesian (HF) cows housed on an outdoor wood-chip pad during 1 estrous cycle (22 d). Other social behavior was recorded during STE and, for comparison, during 1 selected day when none of the cows were in estrus. Standing stationary when mounted was defined as the primary estrus sign. Anogenital sniff, chin rest, attempt to mount, and mount were defined as secondary estrus signs. Ovarian cyclicity was confirmed by progesterone measurements. This study reports short mean duration of STE (7.1±1.44h) and estrus (mount period; 12.9±1.84h) of the 13 cows expressing these signs. All mounting activities involved at least one cow in, or within 4h of, STE. The most frequent sign during STE was anogenital sniff initiated, followed by chin rest received, chin rest initiated, chase up initiated, anogenital sniff received, mount initiated, head butt, mount received, attempt to mount initiated, push away received, play rub, attempt to mount received, follow initiated, threat received, flehmen, avoid, bellow, and social lick received. Standing and mounting activity in HF cows was inconsistent during estrus, indicating that other signs could be of greater use. The frequency of secondary estrus signs initiated and received increased gradually during the last 12h before STE, revealing significant differences between periods from 4 to 6 and 1 to 3h before STE. A considerable increase in receptive behavior (secondary estrus signs received) was identified between 1 to 3h prior to STE and STE. Both frequent initiated and received behaviors were associated with STE. A significant decrease in the frequency of secondary estrus signs initiated and received occurred 3h after STE. Cows in STE simultaneously predominantly chose the other standing cow as mate and expressed secondary estrus signs more frequently. Based on the results of this study, we suggest that chase up could be regarded as a reliable indicator of estrus and that the changes in proceptive (initiated) and receptive (received) behavior could be used as predictors of different stages in estrus. Knowledge of these behavioral signs may improve heat detection rates and the ability to predict the optimum breeding time for dairy cows.

Ultradian activity rhythms in large groups of newly hatched chicks (Gallus gallus domesticus).

A clutch of young chicks housed with a mother hen exhibit ultradian (within day) rhythms of activity corresponding to the brooding cycle of the hen. In the present study clear evidence was found of ultradian activity rhythms in newly hatched domestic chicks housed in groups larger than natural clutch size without a mother hen or any other obvious external time-keeper. No consistent synchrony was found between groups housed in different pens within the same room. The ultradian rhythms disappeared with time and little evidence of group rhythmicity remained by the third night. This disappearance over time suggests that the presence of a mother hen may be pivotal for the long-term maintenance of these rhythms. The ultradian rhythm of the chicks may also play an important role in the initiation of brooding cycles during the behavioural transition of the mother hen from incubation to brooding. Computer simulations of individual activity rhythms were found to reproduce the observations made on a group basis. This was achievable even when individual chick rhythms were modelled as independent of each other, thus no assumptions of social facilitation are necessary to obtain ultradian activity rhythms on a group level.

Can one unrestricted meal buffer the effects of previous pre-meal intervals on the feeding behaviour of sheep?

Varying the time since the last meal is one means of manipulating feeding motivation. In order to use this method effectively it is necessary to know whether and the extent to which effects of one pre-meal interval are carried over to affect the behaviour during the following meals. Pre-meal interval (PMI) is defined here for practical purposes, for short meals, as the time between the start of two successive meals. The possibility that one unrestricted meal might buffer the effects of an 8h as opposed to a 4h PMI on aspects of feeding behaviour was studied with eight Scottish Blackface sheep. They were fed on a regime in which they were given access to food until they finished their meal and lay down (this always occurred within 60min) at which time the remaining food was withdrawn. Feeding behaviour was recorded during the meal after these 4 and 8h intervals, as well as during the following meal 4h later.At a meal after a PMI of 8h, compared to 4h, sheep had a higher intake per meal (mean+/-S.T.D. for 8 and 4h PMI, respectively: 604.4+/-78.8 and 430.1+/-100.9g; P<0.001), a longer meal duration (27.1+/-7.5 and 21.8+/-8.1min; P<0.001), and a tendency for a higher intake rate (23.8+/-6.2 and 21.9+/-8.2g/min; P=0.11). During the following meal 4h later these differences were smaller, but intake per meal still tended to be higher (430.8+/-81.5 and 338.5+/-45.6g; P<0.06) for sheep who had previously had the 8h PMI. Meal duration (21.9+/-7.2 and 20.6+/-7.08min; P=0.28) and intake rate (21.2+/-6.1 and 18.7+/-7.2g/min; P=0.13) were no longer different.A single meal after the different PMIs reduced differences in all three aspects of feeding behaviour observed during the subsequent meal, 4h later, but differences in intake per meal were still apparent. It is suggested that an additional meal may overcome the carry-over effect.

[A hemorrhagic acral form of dyskeratosis follicularis Darier]. / Eine hämorrhagische akrale Verlaufsform der Dyskeratosis follicularis Darier.

A 76-year-old woman presented with a venous leg ulcer 7. Incidentally hemorrhagic macules on hands and fingers and dystrophy of toe and fingernails were noticed. Except for submammary erythema, no further dermatologic signs were shown. Histology of palmar lesions fit with a hemorrhagic lesion of dyskeratosis follicularis in acral skin. During following months actinic induced reddish-brown hyperkeratotic papules appeared on the forehead and in seborrheic and intertriginous areas of the trunk. Papules were most prominent during summer and almost completely resolved in winter. The hemorrhagic variant of dyskeratosis follicularis represents a rare clinical variant which has to be separated from other purpuric macules on acral sites.

Manipulating odor cues facilitates add-on fostering in sheep.

Manipulating the odor of a ewe's own and alien lambs has been used to facilitate fostering a second lamb on ewes with a single offspring (add-on fostering). Previous research has demonstrated that familiar odor cues must be present on the own and alien young to achieve successful and rapid adoptions. Familiar odors may consist of natural own-lamb odors or artificial odors previously applied to the lambs involved. In the present study (Exp. 1), an artificial odorant (neatsfoot oil) was applied to the own and alien lambs shortly after birth to establish a common familiar odor. Acceptance tests were conducted daily over a 72 h period. In Exp. 2, neatsfoot oil was again used as a common artificial odorant to facilitate add-on fostering, but, in addition, the natural odors of own and alien lambs were transposed by exchanging cloth stockinette jackets worn by the lambs. In Exp. 1, 9 of 18 ewes (50%) met the criteria for accepting their own and alien lambs within 72 h. Seven of these nine ewes (78%) accepted the alien lamb immediately. In Exp. 2, 24 of 30 ewes (80%) accepted their own and alien young, and 20 of the 24 acceptances (83%) were immediate. We conclude that add-on fostering may be limited only by our inability to properly match familiar-odor cues on own and alien lambs.

Transition of horizontal to vertical growth phase melanoma is accompanied by induction of vascular endothelial growth factor expression and angiogenesis.

Melanoma progression in general is characterized by an increase in both metastatic frequency and the vascular density of the tumour tissue. Although a direct correlation between these two parameters in individual cases seems to be lacking, it is clear that metastasis is invariably preceded by angiogenesis. One of the angiogenic factors that is produced by human melanoma cells is vascular endothelial growth factor (VEGF). To investigate the role of this factor in the angiogenic process in primary cutaneous melanoma we determined the mean vascular density and the presence of VEGF protein in biopsies of human lesions. The results were compared with those found in normal skin or uninvolved skin from melanoma patients. In addition, we studied morphological and antigenic features of the proliferating neovasculature. We show that (1) the mean vascular density gradually rises along with melanoma progression, (2) transition of horizontal to vertical growth phase melanoma is accompanied by induction of VEGF protein expression and accumulation of this factor in the stroma, (3) vertical growth phase melanoma is often organized in nodules separated by septa containing blood vessels, but without lymphatics, and (4) blood vessel lumina in vertical growth phase melanoma are separated from tumour nodules by two basal lamina containing collagen type IV and the endothelium shows activated morphology and focal expression of the adhesion molecule E-selectin. Our findings indicate that VEGF is a prominent angiogenic factor in melanoma angiogenesis. Although its expression is induced during progression, the effect of VEGF on the incidence of metastasis is probably indirect.

Lack of lymphangiogenesis in human primary cutaneous melanoma. Consequences for the mechanism of lymphatic dissemination.

Cutaneous melanoma has an initial preference for lymphatic spread. Remarkably, melanoma progression toward this metastasizing phenotype is accompanied by intense blood vessel angiogenesis (hemangiogenesis), but lymphangiogenesis, the formation of new lymph vessels in the tumor, has never been reported. To investigate how primary melanoma cells interact with the existing lymphatic microvasculature, and whether lymphangiogenesis occurs, an immunostaining was developed that differentially decorates blood and lymph vessels in frozen tissue sections. The density and distribution of both these vessel types in and around thin (< or = 1.5 mm) and thick (> or = 1.5 mm) primary melanoma lesions and in normal and uninvolved skin were determined. Although especially in thick melanoma lesions a significant increase in blood vessel density was observed, lymphatic density remained unaltered, showing that lymphangiogenesis did not occur. Morphological analysis indicated, however, that melanoma progression is accompanied by a sequence of events that involves hemangiogenesis supporting tumor expansion, especially in the vertical growth phase. Often, stromal sepia are formed around the blood capillaries in the tumor neovasculature protecting them from invasion. Lymph vessels inside the tumor were infrequently observed. However, subepidermal lymph vessels often seemed to be entrapped and penetrated by the expanding tumor mass. In this way, hemangiogenesis, as the driving force behind tumor expansion, might indirectly increase the chance of lymphatic invasion in the absence of lymphangiogenesis. This model explains the paradox that, although melanoma metastasis seems to require angiogenesis, a consistent relation of prognosis with blood capillary density in primary cutaneous melanoma is lacking.

Phenotype of normal cutaneous microvasculature. Immunoelectron microscopic observations with emphasis on the differences between blood vessels and lymphatics.

The lymphatic system has been poorly characterized in comparison to the blood vessels. We investigated the expression of microvasculature markers in cutaneous lymphatics and blood microvessels in normal skin. Scrotal skin was chosen because of its high density of both types of microvessels. A pre-embedding peroxidase-conjugated immunoelectron microscopy technique was used, allowing both the visualization of the lymph and blood vessels and their immunohistochemical staining. The markers studied included endothelial antigens (recognized by PAL-E, EN-4, and von Willebrand factor/factor VIII-related antigen), structural molecules of the vascular wall (alpha-smooth muscle actin, heparan sulfate proteoglycan, collagen type IV), and adhesion molecules (endothelial leukocyte adhesion molecule-1 [E-selectin], intercellular adhesion molecule-1 [ICAM-1], platelet endothelial adhesion molecule-1 [PECAM-1], vascular cell adhesion molecule-1 [VCAM-1]). It is shown that lymphatics of normal skin are phenotypically different from blood microvasculature, only weakly expressing endothelial markers (EN-4+, von Willebrand factor/factor VIII-related antigen +/-, PAL-E-), mural markers (alpha-smooth muscle actin-, heparan sulfate proteoglycan-, collagen type IV+) and do not express the studied adhesion molecules except PE-CAM-1 (E-selectin-, ICAM-1-, PECAM-1+, VCAM-1-). The results were substantiated by a double-labeling immunoelectron microscopic technique, which facilitates detection and assessment of microvascular segments. By this technique, collagen type IV, recognized by a peroxidase-labeled 2nd antibody, stains the basal lamina by a linear pattern, whereas a second optional epitope is visualized as grains by a silver-enhanced ultra-small gold-conjugated antibody. Our study shows that not only morphology but also antigenic phenotype of lymphatics differs significantly from blood vessels.

Atypical varicella-zoster virus infection in an immunocompromised patient: result of a virus-induced vasculitis.

We describe a patient with cutaneous T-cell lymphoma in whom persistent, painless, ecthymatous nodules developed as a result of a varicella-zoster virus infection. The localized infection occurred without a vesicular stage. Ultrastructural studies revealed a lack of epidermal involvement and massive varicella-zoster virus replication within endothelial cells, leading to an obliterative vasculitis. This suggests direct infection of dermal vessels from adjacent nerves, bypassing the epidermis, which is usually infected first in the classic infectious pathway during varicella-zoster virus reactivation from sensory nerves.

[Inflammatory type of epidermolysis bullosa acquisita]. / Inflammatorischer Typ der Epidermolysis bullosa acquisita.

Epidermolysis bullosa acquisita (EBA) is an autoimmune subepidermal blistering disease, which can present in various clinical forms. We report on a 73-year-old male patient with the inflammatory type of EBA, which is clinically similar to bullous pemphigoid. Histological examination revealed subepidermal blister formation, and direct immunofluorescence of perilesional skin revealed a linear deposition of IgG and C3 at the basement membrane. Indirect immunofluorescence with 0.9% NaCl-separated human skin as substrate showed the presence of circulating antibodies binding to the base of the artificial blister at a titre of 1:320. Indirect immunoelectronmicroscopy revealed immune deposits localized in the area of the sublamina densa. Immunoblotting of dermal extracts disclosed binding of serum antibodies to a 290-kDa protein. Systemic therapy with diaminodiphenyl sulphone, initially in combination with corticosteroids, resulted in complete healing of the skin lesions. With reference to this case report, we discuss the clinical pictures possible in EBA, the differential diagnosis and the treatment options.

Measures of libido and their relation to serving capacity in the ram.

The purpose of this study was to determine whether the ejaculation rate (serving capacity) of sexually experienced rams could be estimated by selected measures of sexual libido when rams were exposed to estrous ewes under conditions that prevented copulations. Twenty-four crossbred rams selected for either high or low rates of copulation were exposed to two restrained estrous ewes under three treatment conditions that 1) permitted the full range of precopulatory and copulatory behaviors, 2) permitted precopulatory behaviors and mounting but precluded copulation, or 3) permitted precopulatory behaviors but not mounting or copulation. Frequencies of precopulatory behaviors (bouts of leg-kicking and anogenital sniffing) in each of the three treatment conditions and mounting frequency in Treatment 2 occurred in proportion to the ram's characteristic ejaculation rate (P < .001), suggesting that the mating potential of rams can be estimated under conditions that preclude copulation. Frequencies of precopulatory behaviors and mounting were lower when the rams were allowed to copulate, due largely to periods of sexual inactivity after ejaculations.