Validation of the Unesp-Botucatu pig composite acute pain scale (UPAPS) in piglets undergoing castration.

To accurately assess pain and support broadly-based analgesic protocols to mitigate swine pain, it is imperative to develop and validate a species-specific pain scale. The objective of this study was to investigate the clinical validity and reliability of an acute pain scale (UPAPS) adapted for newborn piglets undergoing castration. Thirty-nine male piglets (five days of age, 1.62 ± 0.23 kg BW) served as their own control, were enrolled in the study and underwent castration in conjunction with an injectable analgesic administered one-hour post-castration (flunixin meglumine 2.2 mg/kg IM). An additional 10, non-painful female piglets were included to account for the effect of natural behavioral variation by day on pain scale results. Behavior of each piglet was video recorded continuously at four recording periods (24 h pre-castration, 15 min post-castration, 3 and 24 h post-castration). Pre- and post-operative pain was assessed by using a 4-point scale (score 0-3) including the following six behavioral items: posture, interaction and interest in surroundings, activity, attention to the affected area, nursing, and miscellaneous behavior. Behavior was assessed by two trained blinded observers and statistical analysis was performed using R software. Inter-observer agreement was very good (ICC = 0.81). The scale was unidimensional based on the principal component analysis, all items except for nursing were representative (rs ≥ 0.74) and had excellent internal consistency (Cronbach's alpha ≥ 0.85). The sum of scores were higher in castrated piglets post-procedure compared to pre-procedure, and higher than in non-painful female piglets confirming responsiveness and construct validity, respectively. Scale sensitivity was good when piglets were awake (92.9%) and specificity was moderate (78.6%). The scale had excellent discriminatory ability (area under the curve > 0.92) and the optimal cut-off sum for analgesia was 4 out of 15. The UPAPS scale is a valid and reliable clinical tool to assess acute pain in castrated pre-weaned piglets.

Effects of season, truck type, and location within truck on gastrointestinal tract temperature of market-weight pigs during transport.

Two experiments were done to assess the effects of season, truck type, and location in the truck on the gastrointestinal tract temperature (GTT) of market-weight pigs during transport. In Exp. 1, a total of 504 sentinel pigs were selected from a total load of 3,756 pigs over 12 wk in summer or winter and transported in either a double-decked (DD) hydraulic truck or a pot-belly (PB) trailer for 2 h. In Exp. 2, a total of 330 sentinel pigs were selected from a total load of 2,145 pigs over 11 wk in summer or winter and transported in a PB trailer for 8 h. In both experiments, sentinel pigs were equipped with a temperature data logger for the real-time GTT recording from the farm to slaughter. Transport was divided into 8 periods in Exp. 1 (rest, pretravel, initial travel, prearrival 1, prearrival 2, unloading, lairage 1, and lairage 2) and in Exp. 2 (rest, pretravel 1, pretravel 2, travel, prearrival 1, prearrival 2, lairage 1, and lairage 2). A delta GTT (ΔGTT) was calculated as the difference between the measured GTT at any determined event and the GTT measured at rest. In Exp. 1, the ΔGTT of pigs was greater ( < 0.001) in summer than in winter and only during the pretravel and initial travel periods. No difference was observed in the ΔGTT between the 2 truck types ( > 0.10). In summer, pigs located in the front top and rear top compartments of the PB trailer presented greater ( < 0.05) ΔGTT values than those transported in the middle top and front belly compartments during initial travel. In summer, during prearrival 1 and 2, a greater ( < 0.05) loss of GTT was found in pigs located in the rear top compartment of the DD truck compared with the rear lower compartment and in the front middle compartment compared with the rear middle compartment of the PB trailer. In Exp. 2, the ΔGTT of pigs was greater ( = 0.03) in summer than in winter during pretravel 2. Pigs in the front top compartment had a greater ( < 0.05) ΔGTT compared with pigs in the middle top, lower deck, and front belly compartments during the pretravel periods. Based on the results of the 2 experiments, modifications of the PB trailer model are recommended to limit body temperature increase due to physical stress at loading and unloading, and during transport due to inconsistent ventilation rate across vehicle locations.

Effect of drinker type on water intake and waste in newly weaned piglets.

During the first few days after weaning, pigs often experience BW loss as they adapt to eating solid food. During this time period, they are also known to drink excessively and develop abnormal oral behavior such as belly nosing. The excessive drinking may stem from the piglets' attempt to satiate hunger through gut fill from a familiar ingestive source. Gut fill through water intake may affect the establishment of feeding behavior. Using drinker devices other than the standard nipple drinker may ease the piglets' transition at weaning by facilitating the initiation of feeding and preventing the development of behavioral problems such as excessive drinking and belly nosing. In this experiment, we examined the effect of drinker type on water and food intake, growth rates, and belly nosing in newly weaned piglets. Eighteen pens of 15 piglets each (270 piglets total) were weaned at 18.1 +/- 0.1 d of age and housed in pens containing 1 of 3 drinker devices (standard nipple, push-lever bowl, and float bowl). Piglets' water and feed intake, water use, BW, and behavior were examined on a pen basis through 2 wk after weaning. Piglets with nipple drinkers wasted more water than the other piglets (P < 0.001; float, 295 +/- 70 mL x pig(-1) . d(-1); nipple, 1,114 +/- 63 mL x pig(-1) . d(-1); and push-lever, 186 +/- 63 mL x pig(-1) . d(-1)), whereas piglets with float bowls consumed less water than the other piglets (P < 0.001; float, 475 +/- 81 mL . pig(-1) x d(-1); nipple, 870 +/- 76 mL x pig(-1) . d(-1); push-lever, 774 +/- 76 mL x pig(-1) . d(-1)). Drinker type affected feeding behavior (P = 0.02); piglets with push-lever bowls spent less time at the feeder than the other piglets, although no difference was detected for feed intake (P = 0.64) or overall ADG (P = 0.16). Piglets with push-lever bowls also tended to perform less piglet-directed nosing behavior than piglets with the float bowl (P = 0.04). Piglets appear to use more water during the first 2 d after weaning with certain drinker devices. However, piglets do not appear to attain satiety through water consumption because most of the water used during the first few days after weaning is wasted. This excessive drinking and water wastage can be abated through the use of push-lever drinkers without negative implications for feed intake or growth rates.

Oculomotor defects in patients with Huntington's disease and their offspring.

We recorded saccadic, pursuit and fixation eye movements in patients (n = 5) with moderately advanced Huntington's disease (HD), offspring of HD patients (n = 22) and control subjects (n = 15), using the scleral sensor coil technique. Saccadic slowing was seen in all patients, no controls and (marginally) in a few at-risk subjects. Fixational stability was lower in patients than in the other groups; a structured background enhanced the difference and revealed decreased stability in a number of at-risk subjects. Smooth pursuit showed large errors in most patients and several controls but none of the at-risk subjects. Sporadic follow-up data show that at least two of the at-risk subjects developed manifest HD within a few years after passing the oculomotor test with entirely normal results. The material as a whole suggests that oculomotor dysfunction does not develop prior to, but concurrently with and as a part of generalized, progressive deterioration of motor control. The implication is that oculomotor screening of clinically healthy at-risk subjects does not reliably contribute to an earlier diagnosis of future HD.

Human fixation and pursuit in normal and open-loop conditions: effects of central and peripheral retinal targets.

Eye movements were recorded precisely with a scleral-coil method under three experimental conditions: fixation of a central, stationary target; pursuit of a central, moving target; pursuit of eccentric, moving targets. Subjects were instructed to attend to and fixate the target and to pursue it when it moved. The target was presented either in darkness (no visible background), on a diffusely lighted background, or on a large, structured background. Target and/or background could be moved independently with single sinusoids, pseudo-random mixtures of sinusoids or triangular waves. The target was usually presented under normal viewing conditions, but in some measurements (interleaved with normal ones) retinal target motion was uncoupled from eye motion by electronical addition of the eye position to the target position (open-loop conditions). The gain and phase relations of eye movements induced by motion of the target and/or background were calculated for the total, composite (smooth and saccadic) eye movement and for the reconstructed cumulative smooth component separately. Horizontal motion of a large, structured background induced correlated smooth eye movements while subjects fixated a stationary point target. The induced horizontal movements were very small (gain about 0.05) when the target was seen normally, and larger (gain about 0.20) when the target was horizontally stabilized on the retina. The phase lag of the induced eye movements relative to the background movements was usually smaller than 90 deg. When the target moved vertically and the background horizontally, vertical pursuit was similar to that with a stationary background, but in addition horizontal smooth eye movements, correlated with the background movements, were elicited with a gain of about 0.1 and a phase lag which was usually smaller than 90 deg. Imposed pseudo-random retinal motion of a central target under open-loop conditions (retinal image motion uncoupled from eye movements) elicited highly idiosyncratic responses which varied too much among subjects to allow any general conclusions, other than that open-loop stimulation seems unsuitable as a tool for analysing the response characteristics of the smooth pursuit system. In the absence of a background, an eccentric target configuration (two vertically aligned arrows with the points localized 5 deg above and 5 deg below the fovea) in horizontal motion was pursued equally well as a central target.(ABSTRACT TRUNCATED AT 400 WORDS)

Human smooth and saccadic eye movements during voluntary pursuit of different target motions on different backgrounds.

Horizontal and vertical eye movements of ten human subjects were recorded with a scleral induction-coil technique during voluntary pursuit of sinusoidal, triangular and pseudo-random target motions of different frequency, amplitude and dimensionality upon a dark, diffuse or structured background. Data processing included separation of the composite eye movement into a cumulative smooth and saccadic displacement, computation of gain and phase of the composite and smooth eye movements with respect to the target movement and analysis of retinal position error. Pursuit eye movements were never completely smooth. Smooth pursuit gain was always lower than 0.95 and saccades were used to supplement the smooth eye movements in pursuing the target with the proper amplitude. The gain of composite eye movements was about unity for sinusoidal target motions and ramps; it exceeded unity for the highest frequency components in a pseudo-random motion. The gain of the smooth eye movements decreased monotonously whenever target velocity increased. It was higher for single sine waves than for a pseudo-random motion, however, with pseudo-random motion it was relatively higher for the higher frequency components. Phase lags were in general smaller for single sine waves than for pseudo-random motion, but for the latter a phase lead of the smooth component was consistently found for the lower frequency components. During pursuit of a rhomboid trajectory, the eye movements showed directional errors which are interpreted as anticipatory behaviour. The distribution of the retinal error was symmetrical around zero. Its standard deviation varied between about 0.2 and 1.3 degrees; it was about proportional to target velocity and inversely proportional to smooth pursuit gain. It was limited by the insertion of saccades which were in general corrective. The influence of a diffusely illuminated background was minimal. A structured background inhibited smooth pursuit in the horizontal direction by about 10% and in the vertical direction by about 20%. This deficit of smooth pursuit was fully compensated by the insertion of more saccades and had no consequences for the standard deviation of the retinal error. The type of structure of the background was only of marginal importance. Horizontal pursuit was in general slightly smoother and more precise than vertical pursuit.

Voluntary selection of the target for smooth eye movement in the presence of superimposed, full-field stationary and moving stimuli.

Prior work has shown that smooth eye movements in the presence of both stationary and moving stimuli are determined, at least in part, by the voluntary selection of either the stationary or the moving stimulus as the target for smooth eye movements. The effectiveness of voluntary selection in eliminating the influence of the stimuli not selected (i.e. backgrounds) on smooth eye movement is not known because prior studies used targets and backgrounds with different physical characteristics. Thus, effects of voluntary selection were confounded with the relative strength of target and background as stimuli for smooth eye movements. We measured eye movements (resolution 1') of two highly-experienced eye movement subjects with a target and background with the same physical characteristics: two, identical, full-field, superimposed patterns of randomly-positioned dots (1 dot/deg2 or 8 dots/deg2). One field was stationary and the other moved at 70.2 minarc/sec. The effect of the moving background on smooth eye movements when the stationary field was the target, and the effect of the stationary background on smooth eye movements when the moving field was the target was negligible (0-4% for one subject; 0-2% for the other). The influence of the background on smooth eye movements was affected by a six-fold reduction in the intensity of either the target or background, but effects of such intensity changes were small and different for each subject. Taken together, these results show that the effectiveness of voluntary selection in eliminating the influence of background stimuli on smooth eye movements can be virtually complete. Any observed influence of the background--however small--can be attributed to voluntary factors (e.g. subjects' failure to apply sufficient effort or attention) rather than to the operation of an involuntary mechanism that automatically integrates velocity information from target and background. The attention and effort required to ensure that voluntary selection is perfect may impair the accuracy of psychophysical judgments made about the background.

A comparison of oculomotor pursuit of a target in circular real, beta or sigma motion.

Pursuit of a point target in real or apparent motion upon a dark, diffusely lighted or structured background was recorded with a scleral coil technique. Smooth and saccadic components were separated and analyzed with computer techniques. Sigma-pursuit was superior to pursuit of beta- or real motion: smooth pursuit gain was higher, saccadic rate was lower and the detrimental effect of a structured background was smaller. Due to directional errors, smooth pursuit velocity often exceeded target velocity when this was smaller than about 10 degrees/sec. However, the smooth component in the correct direction of the target motion had a gain less than or equal to 1.0 and decreasing at higher target velocities for all pursuit modes, inclusive sigma-pursuit.