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PubMed1990

Demonstration of the scapholunate space with radiography.

The importance of radiographic evaluation of the scapholunate space, which should not be wider than 2 mm, has been well established in cases of wrist injury. Unfortunately, the assessment of this space is not accurately determined with routine posteroanterior (PA) radiographs, because the scaphoid and lunate bones often overlap. Moreover, the exact portion of the scapholunate space that should be measured has never been clearly defined. Nine wrists with a scapholunate space no wider than 2 mm and without chondrocalcinosis were studied by means of plain routine views and special projections, transaxial and coronal computed tomographic scans, and dissection to determine the precise orientation and anatomy of this space. A PA radiograph with 10 degrees of tube angulation from the ulna toward the radius best demonstrated the scapholunate space. This space should be measured at the level of the midportion of the flat lateral facet of the scaphoid.

Carpal Bones↗
PubMed1993

Wide scapholunate joint space in lunotriquetral coalition: a normal variant?

The radiologic appearances of 70 lunotriquetral coalitions in 52 patients were evaluated to determine whether a wide scapholunate joint space in subjects with this congenital abnormality reflects a scapholunate ligament disruption or is a normal variant. When the middle of the scapholunate joint space was larger than the capitolunate or third carpometacarpal joint space widths, it was considered to be abnormally wide. In 32 of 70 wrists (46%), a wide scapholunate joint space was detected. Results of instability radiographic series (n = 28) and arthrography (n = 11) were normal with respect to the scapholunate ligament in all cases, but the scapholunate joint space was markedly widened in six cases (55%) in which arthrography was performed. Arthroscopy, performed in one case, showed an intact scapholunate ligament. Because of the high prevalence of a wide scapholunate joint space and because of negative arthrographic and arthroscopic examinations, the authors conclude that widening of the scapholunate joint space is a normal variant that is common in patients with lunotriquetral coalition.

Adolescent↗
PubMed2002

Distal air space epithelial fluid clearance in near-term rat fetuses is fast and requires endogenous catecholamines.

Knowledge about the conversion of the epithelium in the distal air spaces of the lung from secretion to absorption is imperative to the understanding of postnatal lung development; little such information is available in rats. Distal air space fluid clearance was therefore measured in 21- to 22-day gestation rat fetuses and newborn (40 h) rats. Distal air space fluid clearance was measured from the increase in (131)I-albumin concentration in an isosmolar, physiological solution instilled into the developing lungs. There was no net fluid movement across the distal air space epithelium in the lungs of 21-day gestation fetuses. Twenty-four hours later, distal air space fluid was cleared at a rapid rate in the 22-day gestation fetuses. Within the first 40 h after birth, the rate rapidly declined to adult levels. The high distal air space fluid clearance at 22 days gestation and at 40 h after birth was mediated by beta-adrenergic receptors as demonstrated by elevated plasma epinephrine levels and inhibition by propranolol. Interestingly, the elevated distal air space fluid clearance in the 22-day gestation fetuses was only minimally amiloride sensitive; however, amiloride sensitivity increased over the first 40 h after birth. In conclusion, these studies demonstrate that 1) rapid rates of net alveolar fluid clearance occur late in gestation in the rat and 2) this clearance is driven by elevations of endogenous epinephrine.

Adrenergic beta-Antagonists↗
PubMed1991

No evidence for mesothelial cell contact across the costal pleural space of sheep.

Pleural space width was measured by four morphological approaches using either frozen hydrated or freeze-substituted blocks of chest wall and lung. Anesthetized sheep were held in the lateral (n = 2), sternal recumbent (n = 2), or vertical (head-up; n = 2) position for 30 min. The ribs and intercostal muscles were excised along a 20-cm vertical distance of the chest wall region, which was sprayed with liquid Freon 22, cooled with liquid nitrogen, to facilitate the fastest possible freezing of the visceral and parietal pleura. We measured pleural space width in frozen hydrated blocks by reflected-light and low-temperature scanning electron microscopy and in freeze-substituted, fixed, and embedded tissue blocks by light and transmission electron microscopy. We combined the data from the two groups of sheep held sternally recumbent and vertical because the results were comparable. The average arithmetic mean data for pleural space width determined by reflected-light analysis for samples near the top (18.5 microns) and bottom (20.3 microns) of the chest, separated by 15 cm of lung height, varied inversely with lung height (n = 4; P less than 0.009). The average harmonic mean data demonstrated a similar gravity-dependent gradient (17.3 and 18.8 microns, respectively; P less than 0.02). Therefore a slight vertical gradient of approximately -0.10 micron/cm of lung height was found for costal pleural space width. Pleural space width in the most dependent recesses, such as the costodiaphragmatic recess, reached 1-2 mm. We never found any contacts between the visceral and parietal pleura with either of the frozen hydrated preparations. No points of mesothelial cell contact were revealed in the light- and transmission electron microscopic views of the freeze-substituted tissue, despite an apparent narrower pleural space associated with the tissue-processing steps. We conclude that the pleural space has a slightly nonuniform width, contacts if they occur must be very infrequent, and pleural liquid clearance is probably facilitated by liquid accumulation in dependent regions where lymphatic pathways exist.

Animals↗
PubMed1994

Monaural and binaural spectrum level cues in the ferret: acoustics and the neural representation of auditory space.

1. The role of the structures of the outer ear in producing monaural and binaural spectral cues to sound location was examined acoustically in the ferret. A probe microphone was introduced across the wall of the external auditory canal and its responses to digitally constructed wideband signals were recorded for a large number of free field locations. 2. In the intact animal the patterns of both monaural and binaural cues were asymmetrical for horizontal locations about the interaural axis. For anterior sound locations the monaural transformations demonstrated relative gains at middle and high frequencies and a location-dependent frequency notch. Changing elevation resulted in variations in the corner frequencies of these spectral features. Additionally, there was greater front-back asymmetry in the binaural spectral cues for locations in lateral space when compared with locations near the midline. 3. Surgical removal of the pinna and concha (pinnectomy) eliminated all the major front-back asymmetrical features in the horizon monaural and binaural spectral transformations as well as the elevation-dependent variations in the monaural spectra. Thus the residual transformations were ambiguous for sound locations in lateral space, resulting in "cones of confusion" centered on the interaural axis. 4. These cues were reflected in the topographic representation of auditory space in the deeper layers of the superior colliculus (SC). Previous studies have shown that spatial tuning at near-threshold sound levels is based on monaural pinna cues, whereas binaural inputs are utilized at higher levels that stimulate both ears. In the intact ferret we examined statistically the topography of the representation of sound azimuth for near-threshold and suprathreshold stimuli and the alignment of the auditory and visual representations in the SC. The distributions of auditory best positions within the SC for near- and suprathreshold stimulus levels were statistically indistinguishable, suggesting that both monaural and binaural cues are integrated in this neural representation of space. 5. Pinnectomy resulted in a large increase in the number of auditory units that responded best to two distinct locations in space. One lobe of the response was tuned appropriately in terms of the position of the unit within the SC, demonstrating that the residual acoustical cues are sufficient for the construction of a topographic representation of auditory space. However, the second region of space, thereby producing an ambiguous representation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

Trajectory adaptation to a nonlinear visuomotor transformation: evidence of motion planning in visually perceived space.

1. Although reaching movements are characterized by hand paths that tend to follow roughly straight lines in Cartesian space, a fundamental issue is whether this reflects constraints associated with perception or movement production. 2. To address this issue, we examined two-joint planar reaching movements in which we manipulated the mapping between actual and visually perceived motion. In particular, we used a nonlinear transformation such that straight line hand paths in Cartesian space would result in curved paths in perceived space and vice versa. 3. Under these conditions, subjects learned to make straight line paths in perceived space even though the paths of the hand in Cartesian space were markedly curved. In contrast, when the motion was perceived in Cartesian space (i.e., in the absence of a nonlinear distortion), straight line hand paths were observed. 4. These findings suggest that visually guided reaching movements are planned in a perceptual frame of reference. Reaching movements in the horizontal plane are adapted so as to produce straight lines in visually perceived space.

Adaptation, Physiological↗
PubMed2004

Radial distribution of dilated intercellular spaces of the esophageal squamous epithelium in patients with reflux disease exhibiting discrete endoscopic lesions.

INTRODUCTION: Dilatation of intercellular spaces of the esophageal squamous epithelium has been suggested as a marker of early acid reflux-induced damage. This change is a potentially useful addition to histomorphological changes that represent so called minimal endoscopic lesions. We have assessed dilatation of intercellular spaces with regard to: (1) interobserver variability, and (2) whether the incidence of this varies between 'red streaks' and the adjacent normal looking squamous epithelium. METHODS: Esophageal biopsies from 44 patients with chronic gastro-esophageal reflux (GERD) were evaluated. At endoscopy, these patients had one or more red streaks on the tops of the mucosal folds in the distal esophagus. Biopsies were taken from the red streaks and from the normal-appearing mucosa 1 cm lateral to the red streaks. Biopsies were assessed in a blinded fashion by two independent pathologists (MV & RF). Criteria for assessing intercellular space dilatation were evaluated and agreed on prior to the study. RESULTS: Good interobserver agreement was recorded (kappa = 0.82 at the streaks and 0.77 for the control tissues) for absence/presence of intercellular space dilatation. Red streak and control biopsies differed significantly (p = 0.0001), with respect to presence of dilated intercellular spaces, with 90.5 % of the former demonstrating this as present compared to 56.1% in the controls. CONCLUSION: This study supports the concept that esophageal mucosal minimal changes due to reflux is localised and that dilatation of intercellular spaces is an early sign of reflux-induced epithelial damage. The low interobserver variability in the assessment of intercellular space dilatation suggests that this may be a useful variable for assessment of early signs of acid-reflux induced damage to the squamous epithelium of the esophagus by use of light microscopy.

Biopsy↗
PubMedDate not supplied

Bony anatomy of the anterior epitympanic space.

The anatomy of the anterior epitympanic space is complex and relatively unfamiliar to the surgeon. The size of the space is unpredictable. From the surgeon's perspective, we studied the bony anatomy of the anterior epitympanic space in 35 cadavers. There was an impressive variability of bony openness into the anterior mesotympanum; the openness was bilaterally symmetrical. As a potential auxiliary ventilation route for the epitympanum of the chronic otitis patient, each specimen was found to have sufficient room to surgically establish a route at least 2 mm in diameter to connect with the anterior mesotympanum. None of the specimens had dehiscent facial nerve in the anterior epitympanic space, but 60% of specimens had dehiscent facial nerve adjacent to the stapes. The anatomic variations of the anterior epitympanic space were not related to prior otitis media. Three fourths of the medial walls of the anterior epitympanic spaces lacked the bony trabeculae that are otherwise typical of the epitympanum. Because the medial wall contours were bilaterally symmetrical, because the contours were unassociated with indicators of prior otitis media, and because of apparent contour differences in Orientals and Caucasians, a congenital factor is suggested to determine the contour of the medial wall of the anterior epitympanic space.

Adult↗
PubMed2000

Asymmetry of configuration space induced by unequal crossover: implications for a mathematical theory of evolutionary innovation.

Evolution can be regarded as the exploration of genetic or morphological state space by populations. In traditional models of population and quantitative genetics, the state space can be formally represented as a configuration space with clearly defined concepts of neighborhood and distance, defined by the action of variational operators such as mutation and/or recombination. In this paper, we describe a process where no genetic configuration space closure (and hence, no non-arbitrary notion of distance and neighborhood) exists. The process is gene duplication by means of unequal crossover, which we regard as an example of an "innovation" process that changes the state space of the system rather than exploring a closed state space. We assert that such processes are qualitatively distinct from representations of the adaptation process, which occur on regular configuration spaces.

Biological Evolution↗
PubMed1988

Cadmium-chloride-induced air-space enlargement with interstitial pulmonary fibrosis is not associated with destruction of lung elastin. Implications for the pathogenesis of human emphysema.

To determine whether lung elastin is lost during the evolution of cadmium-induced air-space enlargement with pulmonary fibrosis, the lung elastin of 5- to 7-day-old golden Syrian hamster pups was radiolabeled by giving [3H]valine. At maturity, a single intratracheal instillation of 0.5 ml of 0.025% CdCl2 solution was given. Lung mechanics, histologic examination, and biochemistry were studied 5, 10, 21, 42, 105, and 180 days after the cadmium treatment. The animals developed fibrosis and air-space enlargement with decreased lung volumes, compliance, and forced expiratory flow; their functional residual capacity was increased. The total lung collagen and total lung elastin were increased, but there was no loss of radiolabel in lung elastin. We conclude that CdCl2-induced air-space enlargement with pulmonary fibrosis is not accompanied by loss of neonatally formed lung elastic fibers. We hypothesize that air-space enlargement with fibrosis represents a stereotyped response of the lung to fibrosing injuries, which we hypothesize is due to forces from more fibrotic and atelectatic areas causing overdistension of less abnormal air spaces. The air-space enlargement of fibrosing human diseases such as sarcoidosis and eosinophilic granuloma may have a similar basis. Evidence is reviewed that human centrilobular emphysema may be a form of focal air-space enlargement with interstitial fibrosis; there may be mechanisms in addition to elastase-antielastase imbalance that cause human emphysema.

Animals↗
PubMed1985

Sugar clearance from saliva and intra-oral spaces.

The clearance of glucose from saliva was compared with that from spaces located in an intra-oral appliance. The spaces (N = 8) were similar in shape and size to posterior interdental spaces and could be sampled with a microsyringe without removing the appliance from the mouth. The subjects (N = 5) rinsed their mouths with solutions of 5, 10, or 25% glucose. Samples were obtained from a pair of spaces and from saliva at standard intervals and were analyzed for glucose. The rate of glucose clearance was consistently slower from the spaces than from bulk saliva, as shown by higher concentrations and longer clearance times for the spaces. The clearance curves were similar in shape and were rectilinear when the logarithms of the concentrations were plotted against time. The rate of clearance from the spaces appears to be characteristic for an individual, as was also true of salivary clearance.

Adult↗
PubMed2006

Digital radiographic evaluation of medial joint space narrowing after partial meniscectomy of bucket-handle medial meniscus tears in anterior cruciate ligament-intact knees.

BACKGROUND: Few studies exist that evaluate the effect of partial medial meniscectomy in knees with intact anterior cruciate ligaments. HYPOTHESIS: Partial meniscectomy of bucket-handle medial meniscus tears will cause joint space narrowing. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 1982 and 2001, 135 patients met the study criteria of a partial medial meniscectomy, intact ligaments, no surgery to the contralateral knee, and no chondromalacia greater than grade II. Seventy-nine patients living within 150 miles of the clinic were asked to return for physical examination. Joint space narrowing was measured from the middle of the femoral condyle to the middle of the tibial plateau using digitally magnified weightbearing 45 degrees flexed posteroanterior and full-extension anteroposterior radiographs. Measurements were performed twice with the observer blinded to the previous measurements. Subjective follow-up was obtained prospectively on an annual basis with International Knee Documentation Committee and modified Noyes knee questionnaires. RESULTS: Forty-nine patients were examined at a mean of 11.8 years postoperatively. Mean medial joint space narrowing was 1.2 +/- 0.5 mm on 45 degrees flexed posteroanterior radiograph and 0.2 +/- 0.9 mm on full-extension anteroposterior radiographs (P < .001). Four patients had 2 mm or more of joint space narrowing. Subjective surveys obtained from 95 patients showed a mean subjective score of 89.9 points. Subjective scores did not decrease through time, and there was no correlation of joint space narrowing to lower subjective scores. CONCLUSION: Partial medial meniscectomy in stable knees causes only mild joint space narrowing (mean, 1.2 mm) at a mean 12-year follow-up. Digitally magnified 45 degrees flexed posteroanterior radiographs are more likely to demonstrate joint space narrowing than are full-extension anteroposterior radiographs.

Adolescent↗
PubMed2004

In vivo optical imaging of pleural space drainage to lymph nodes of prognostic significance.

BACKGROUND: Understanding the spatial and temporal drainage patterns of the pleural space could have profound impact on the treatment of lung cancer and mesothelioma. The purpose of this study was to identify the in vivo pattern of drainage from the pleural space to prognostic lymph node stations. METHODS: Fifty-six rats underwent pleural space injection of a novel lymph tracer composed of recombinant human serum albumin (HSA) covalently conjugated to the near-infrared (NIR) fluorophore IRDye78 via an amide bond (HSA-78). Nodal uptake was imaged at 10, 20, 30, and 60 minutes and 4, 12, and 24 hours after injection with a custom system that simultaneously acquires color video, NIR fluorescence of HSA-78, and a merged picture of the two. Six pigs underwent the same procedure with imaging at 30 minutes, 1 hour, and 24 hours. RESULTS: In both the rat model and the pig model, HSA-78 drained from the pleural space to superior mediastinal lymph nodes first, followed by other intrathoracic and then extrathoracic lymph nodes over the course of 24 hours. CONCLUSION: NIR fluorescence imaging in two species shows that the superior mediastinal lymph nodes are the first to drain the pleural space. Over the course of 24 hours, the pleural space also communicates with other intrathoracic and then extrathoracic lymph nodes. This study also demonstrates an intraoperative method for identifying nodes communicating with the pleural space, with potential utility in the staging and/or resection of lung cancer and mesothelioma.

Animals↗
PubMed2002

Effects of row spacing and plant density on corn rootworm (Coleoptera: Chrysomelidae) emergence and damage potential to corn.

Planting corn, Zea mays L., in row spacings less than the conventional width of 76 cm has been shown to increase grain yields. This study was conducted to determine if row spacing and plant density affected corn rootworm, Diabrotica virgifera virgifera LeConte and D. barberi Smith & Lawrence, adult emergence, larval injury to the roots, and plant tolerance to injury. Field experiments were conducted at Ames and Nashua, IA, in 1998, 1999, and 2000. Treatments were row spacings of 38 and 76 cm, and plant populations of 64,500 and 79,600 plants per hectare. Adult emergence was 31% greater in 38 cm compared with 76-cm rows. However, root injury was not significantly different between row spacings or plant populations. Row spacing alone did not significantly influence tolerance to injury, measured as root size and the amount of root regrowth. However, at one environment where precipitation was low, plants in 38-cm rows produced 25% more regrowth compared with plants in 76-cm rows. Root dry weight and regrowth were suppressed by 16 and 32%, respectively, at the high plant population. Although lodging was 51% lower in the 38-cm rows compared with the 76-cm rows, grain yields were not significantly different between row spacings. Reducing the row spacing of field corn from 76-38 cm should not increase the potential for injury from corn rootworm larvae.

Agriculture↗
PubMed1995

Distension of extrapleural spaces with contrast medium or air: value in creating safe percutaneous access to the mediastinum in cadavers.

OBJECTIVE: We artificially widened the extrapleural space with contrast medium or air in 33 cadavers to create a safe extrapleural route to the anterior mediastinum and the posterior mediastinum for large-bore needle biopsies. MATERIAL AND METHODS: Under CT guidance, 120 ml of diluted contrast medium (10%) or 300 ml of air was injected percutaneously into the right paravertebral (n = 23) and left retroaortic (n = 5) or ventral parasternal (n = 5) extrapleural spaces. RESULTS: In six of 18 cases, the paravertebral space was found to be wide enough to advance a 14-gauge cannula to the extrapleural paraesophageal space. After injection of 120 ml of diluted contrast medium, the width of the right paravertebral space at the level of the posterior rim of the vertebral body was dilated from a mean of 0.62 cm to 1.06 cm, and the width of the anterior rim was dilated from a mean of 0.91 cm to 1.97 cm. In 17 of 18 cases, the paravertebral space was wide enough to accommodate a 14-gauge cannula. A large osteophyte blocked the access route in one case. Artificial widening regresses within 7 min by an average of 33% at the level of the posterior rim of the vertebral body and by an average of 18% at the level of the anterior rim. Dilatation was significantly more effective with diluted contrast medium than with air. When 120 ml of diluted contrast medium was injected into the left retroaortic extrapleural space, the distance between the aorta and the vertebral column was widened from a mean of 0.40 cm to 1.50 cm. Using a ventral approach for injecting 120 ml of solution, we widened the parasternal access route from a mean of 0.42 cm to 1.90 cm. CONCLUSION: In this cadaver study, artificial dilatation of the mediastinum with diluted contrast medium allowed extrapleural access from right paravertebral, left retroaortic, and parasternal directions for large-bore needle biopsies.

Biopsy, Needle↗
PubMed1996

Extrasynovial spaces of the cruciate ligaments: anatomy, MR imaging, and diagnostic implications.

OBJECTIVE: The purpose of our study was to define the anatomy of the extrasynovial space that cruciate ligaments occupy by examining the pattern on MR imaging of normal fluid distribution in the joints around the cruciate ligaments and correlating this distribution with histologic analysis of synovial reflections around the cruciate ligaments. MATERIALS AND METHODS: MR images of five cadaveric knees were obtained serially after larger and larger amounts of contrast material were injected into the joint space. The patterns of fluid distribution around cruciate ligaments were noted. In two other cadaveric knees, the synovial sheath around the anterior cruciate ligament was injected directly with contrast material under CT guidance. Anatomic and histologic correlation was made with findings on corresponding MR images. RESULTS: The pattern of fluid distribution is bounded by the synovial reflections around cruciate ligaments. When maximum joint distention is achieved, fluid almost surrounds the cruciate ligaments. The area without fluid is a triangular space between the anterior and posterior cruciate ligaments that appears on the midsagittal image. This triangular space of the cruciate ligaments is an extrasynovial space within which both the anterior cruciate ligament and the posterior cruciate ligament reside. CONCLUSION: The overlying synovial membrane of the cruciate ligaments does not normally allow joint fluid to enter the substance of the ligaments or the triangular space of the cruciate ligaments. Therefore, fluid collections seen on MR imaging in these extrasynovial spaces or structures likely arises from injury to the cruciate ligaments.

Adult↗
PubMed1982

Ultrastructural aspects of the liver perisinusoidal space in diabetic patients with and without microangiopathy.

To determine whether abnormalities of the perisinusoidal space of Disse are present in the liver of diabetic patients with microangiopathy, an ultrastructural stereologic study of the space of Disse was performed in six insulin-treated diabetics with severe performed in six insulin-treated diabetics with severe proliferative retinopathy and six insulin-treated diabetics with normal fluorescein angiography, six patients with familial unconjugated hyperbilirubinemia were studied as controls. No patient had clinical and/or biochemical hepatic abnormalities and none suffered from any of the pathologic conditions known to be associated with collagenization of the perisinusoidal space. In control patients, the space of Disse of liver sinusoids contained occasional small deposits of collagen fibers. The relative volume of these fibers per unit of sinusoid represented 2.63 +/- 0.82%. In all diabetic patients with retinopathy, marked deposition of collagen fibers within the perisinusoidal space was constantly observed, a finding confirmed by ultrastructural stereologic analysis which showed that the relative volume of collagen fibers per unit of sinusoid represented 7.33 +/- 1.44% and differed significantly from control patient values (P less than 0.001). On the contrary, the relative volume of collagen fibers within the space of Disse in diabetic patients without retinopathy (3.95 +/- 2.96%) did not differ significantly from control patient values. These findings demonstrate that collagenization of the space of Disse is positively correlated with the presence of diabetic microangiopathy. Ultrastructural examination of the liver sinusoids might constitute a sensitive and useful approach for detecting the early changes of the microcirculation in diabetic patients.

Adult↗
PubMed1998

Effect of protein levels and space allocations on performance of growing-finishing pigs.

We conducted two trials with growing-finishing pigs (Pig Improvement Company line 405 x Camborough 15) to evaluate the effects of space allocation on performance and CP requirements. In Trial 1, a 2 x 3 factorial (two levels of space, three CP regimens) was used with 252 pigs. Pigs were allocated to either .23, .28, .37, or .50 m2 per pig (crowded) or .37, .47, .60, or .74 m2 per pig (uncrowded) during the 18 to 36, 36 to 55, 55 to 91, and 91 to 127 kg weight periods, respectively. Diets contained 16.1, 18.6, or 21.1% (18 to 36 kg), 15.3, 17.8, or 20.3% (36 to 55 kg), 14.7, 17.2, or 19.7% (55 to 91 kg), and 12.8, 15.3, or 17.8% (91 to 127 kg) CP. The 16.1, 15.3, 14.7, and 12.8 % CP (control) diets contained 1.09, .86, .82, and .65% lysine, respectively. Crude protein levels (Trials 1 and 2) were achieved by substituting soybean meal for corn. In Trial 1, a CP x space interaction ( P < .03) for gain:feed suggested that feed efficiency of grower pigs was improved to a greater extent in uncrowded pigs than in crowded pigs. Grower pigs (18 to 55 kg) with less space had depressed (P < .05) feed intake and gain and a lower (P < .10) feed efficiency than uncrowded pigs. Added CP improved (P < .05) rate and efficiency of gain in grower pigs. Overall (18 to 127 kg), crowded pigs had reductions (P < .05) in gain (17.6%), feed intake (11.3%), and gain:feed ratio (7.1%) compared to uncrowded pigs. Trial 2 involved 216 finishing pigs in a 2 x 2 factorial (two levels of space, two CP regimens). Pigs were provided with either .37 or .50 m2 per pig (crowded) and .60 or .74 m2 per pig (uncrowded) during the 55 to 91 and 91 to 127 kg weight periods, respectively. The diets contained 14.1 or 17.1% CP (55 to 91 kg) and 12.1 or 15.1% CP (91 to 127 kg). Lysine levels were .67 and .53% for the 14.1 and 12.1% CP diets, respectively. Overall (55 to 127 kg), crowded pigs had depressed (P < .05) gains (15.4%), feed intakes (9.5%), and feed efficiencies (6.8%) compared with uncrowded pigs. Increasing CP resulted in improved (P < .05) ADG (7.4%) and gain:feed (8.3%) in crowded and uncrowded pigs. The data suggest that pigs with lower feed intakes as a result of space restrictions do not have higher CP requirements than those with more space.

Animal Feed↗