Influence of age on fibre type characteristics in the middle gluteal muscle of Andalusian foals.

34 Andalusian foals of both sexes were divided into three age-groups (A = mean age 1 month, B = 7 months, C = 14 months). Samples of the right m. gluteus medius were stained for m-ATPase and NADH-TR in order to determine fibre type composition and size as well as the relative area occupied by each type. Results revealed no statistically significant variation in the proportion of type I fibre among the three age-groups. Significant differences were recorded, however, for type II fibres; an increase in the proportion of IIA fibres was accompanied by a decrease in IIB ones, the difference being most marked between groups A and B. IIB high-oxidative fibres also decreased, while IIB low-oxidative ones showed no significant variation. All fibre types increased significantly in size; types I and IIA recorded a threefold increase, whereas type IIB showed least growth. The relative area occupied by each type increased significantly between groups A and B, but only IIA fibres recorded a significant increase in relative area between groups B and C.

Type IIC fibres in certain muscles of the adult rat (sedentary and exercised).

Samples were taken, at fixed levels, of the vastus lateralis, the caput lateralis of the gastrocnemius muscle and the longissimus lumbaris of 72 Wistar rats which were either sedentary or subjected to various exercise schedules. The samples were analyzed using the histochemical technique of myosin ATPase (m-ATPase) after preincubation at pH 4.2, and the fibre-types I, II (IIA and IIB) and IIC were identified, calculating the percentage of type IIC fibres as well as their minimum diameter. The percentages of these IIC fibres found in the red and mixed parts of the gastrocnemius (caput lateralis) and the longissimus lumbaris were between 0.7% and 2.6%. However, their presence was not detected in the vastus lateralis or in the white part of the gastrocnemius (caput lateralis). The lack of differences in this fibre type between the males and females of the population was shown statistically. Likewise, no significant modification of the IIC fibres between sedentary and exercised animals was seen. With regard to fibrillar size, females showed a smaller minimum diameter than males, the results showing a small increase in the size of these fibres in both sexes after exercise, although in most cases this was not statistically significant.

Histogenetic evolution of bovine gastric compartments during the prenatal period.

In order to carry out this study, 62 embryos and fetuses of Friesian cows were used, and every stomach was dissected and subjected to the usual laboratory procedures. After obtaining each preparation all the histological and metrical changes that took place in the wall of the viscus during its development are described. The compartments are histologically differentiated into three stages: in the first one there is no compartment differentiation: in the second one, the rumino-reticulum, omasum and abomasum have differentiated; and in the third one every compartment is differentiated. In group 16, (78 days of gestation), a decrease in thickness of the muscular layer of all compartments, parallel to the histological differentiation has been observed.

Histomorphometric analysis of the reticulum of the sheep during development.

Histomorphometric and scanning electron microscopic analysis were performed on 74 embryos and foetuses and on 20 sheep (early post-natal to adult age). Histodifferentiation of the reticulum took place at 33 days of foetal life. Reticular ribs were observed as evaginations of the epithelial stratum germinativum at 64 days. Neutral mucopolysaccharides first appeared in epithelial cells at 46 foetal days, thereafter to decrease gradually in number, subsequently stabilising in postnatal life. Acid mucopolysaccharides, mucins and mucoid compounds were not detected. Growth curves and formulae were constructed for each tissue layer. Initial test involved multiplicative (y = axb), linear (y = a+bx) and polynomial model (y = a+b+cx2+dx3).

Kinematic characteristics of Andalusian, Arabian and Anglo-Arabian horses: a comparative study.

The aim of this study was to compare the kinematic trot characteristics of three different breeds of horse: Andalusian (AN, n = 15), Arabian (AR, n = 7) and Anglo-Arabian (AA, n = 5) using standard computer-assisted videography (25 Hz). Linear, temporal and angular parameters in fore- and hind limbs were analysed in six randomly selected strides per horse. Normalised angle-time diagrams along the complete stride were obtained for all joints angles in each breed and specific kinematic characteristics were detected graphically. AA horses displayed longer swing durations in both limbs ans a shorter angular range of motion (ARM) in scapula and pelvis inclination and in shoulder, hip and forelimb retraction-protraction angles. At lift off, stifle and tarsal joint angles were more flexed. In general, only small differences were observed in AR horse kinematics when compared with the other 2 breeds. AN horses presented negative overtracking length, which was positive in AR and AA. In AN horses the elbow and carpal joints were more flexed at the moment of maximal elevation, elbow and fore-fetlock joints also exhibited a larger ARM due to a smaller angle at maximal flexion. In the hind limbs, tarsal, hind fetlock and retraction-protraction angles presented a larger ARM in AN horses due to greater maximal flexion in the tarsal and hind fetlock joints. Fore- and hind fetlocks were also more flexed in horses from this breed. In conclusion, differences between kinematic variables at the trot were observed in the three breeds studied here, mainly in forelimb joints. The most outstanding feature was the greater forelimb flexion recorded in AN horses than in the other breeds which is consistent with the elevated movements in this breed. In AA horses, the ARM of proximal joints involved in retraction protraction in both fore- and hind limbs was smaller. All the differences observed highlighted the idiosyncratic nature of the trot in each breed; this may influence the functional capacity of each breed.

Angular kinematic patterns of limbs in elite and riding horses at trot.

Normal speed videography was used to determine the angular parameters of 28 Spanish Thoroughbreds at trot. Horses were divided into 3 groups: Group UT, comprising 9 animals (provided by the VII National Stud, Cordoba, Spain) which had undergone no specific training programme and which were hand led at the trot; Group T, formed by 19 horses considered to be highly bred and trained, and which were also hand led; and Group RT, comprising the same horses as the latter group but this time trotted by a rider. Each animal was filmed 6 times from the right-hand side, using a Hi8 (25 Hz) video camera. Angular parameters for fore- and hindlimb joints were measured in each stride from computer-grabbed frames and entered into a spreadsheet for calculation; parameters included maximum and minimum angles, range of motion, and angles at landing, lift off and maximum hoof height; the times at which maximum angle, minimum angle, lift off and maximum hoof height occurred were calculated as percentages of total stride duration. Stride velocity (mean [s.d.]) was 4.01 (0.62), 3.60 (0.34) and 3.07 (0.36) m/s for Groups UT, T and RT, respectively. Data were then compared between Groups UT-T and Groups T-RT. Compared with Group UT, horses from Group T featured a shorter stance percentage (P<0.001) in both fore- and hindlimbs. The range of motion in forelimbs was smaller (P<0.05), due to lower retraction (P<0.001); moreover, maximum retraction appeared earlier (P<0.05). Greater scapular inclination was in evidence (P<0.05) and the shoulder joint extended further (P<0.05). Fore- and hind fetlock joints revealed a relatively shorter hyperextension period during the stance phase (P<0.01). Compared with Group T, horses from Group RT had a longer stance percentage, with belated maximum retraction of the fore- and hindlimbs. The range of movement in scapular inclination was greater (P<0.05), due to a smaller minimum angle (P<0.01), and the shoulder joint flexed more (P<0.05). The elbow joint extended more and for longer during the stance phase. Initial extension of the hip joint (P<0.05) and tarsus (P<0.001) lasted longer. The carpal and fore and hind fetlock joints recorded relatively longer hyperextension times, in addition to greater hyperextension during the stance phase. The results from the present study suggest that rider-effect must be taken in consideration when well gaited horses are selected for dressage purposes.

Craniofacial angle in dolicho-, meso- and brachycephalic dogs: radiological determination and application.

Observations on craniofacial axes and angles were made on fifty dogs belonging to five breeds, by means of radiological techniques (lateral radiographs) and biostatistical methods. The craniofacial angles were found to be 25-26 degrees (greyhound), 19-20 degrees (pointer), 20-21 degrees (German shepherd), 13-14 degrees (boxer) and 9-10 degrees (Pekinese). Shortening of the head in brachycephalic dogs implies a more perpendicular development of the cranium relative to the facial axis. The possible application of these data in the determination of morphological types in many fields is discussed.

Skeletal muscle fiber size in untrained and endurance-trained horses.

The mean area and minimal diameter of 3 histochemically determined myofiber types (1, 2A, and 2B; myosin ATPase in acid buffer) were calculated in middle gluteal muscle biopsy specimens from 62 stallions, 47 Andalusians and 15 Arabians, ranging in age from 6 to 12 years. Fourteen Andalusians and 7 Arabians were untrained, and the remainder were actively endurance-trained. The 6-month training schedules involved walking, slow trotting, and cantering. Fourteen Andalusians were moderately endurance-trained, whereas the other 19 Andalusians and 8 Arabians were strongly endurance-trained. Significant differences were not recorded between untrained and endurance-trained Arabians with respect to the area (type 1, 3,194 +/- 869 microns 2 and 3,150 +/- 370 microns 2; type 2A, 3,819 +/- 890 microns 2 and 3,380 +/- 356 microns 2; and type 2B, 4,872 +/- 962 microns 2 and 4,417 +/- 646 microns 2) or minimal diameter (type 1, 52.2 +/- 7.4 microns and 52.8 +/- 3.1 microns; type 2A, 58.1 +/- 6.7 microns and 55.0 +/- 2.8 microns; and type 2B, 65.3 +/- 6.4 microns and 63.4 +/- 4.3 microns) of the 3 fiber types, nor between untrained and endurance-trained Andalusians with respect to the area (untrained, 3,990 +/- 690 microns 2; moderately endurance-trained, 3,882 +/- 347 microns 2; and strongly endurance-trained, 3,758 +/- 510 microns 2) and minimal diameter (untrained, 58.1 +/- 4.7 microns; moderately endurance-trained, 59.7 +/- 2.7 microns; and strongly endurance-trained, 58.7 +/- 4.5 microns) of 2A fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Histomorphometric analysis of the omasum of sheep during development.

Histomorphometric and scanning electron microscopic analyses were performed on 74 embryos and fetuses and 20 sheep (early postnatal to adult age). Histologic differentiation of the omasum took place at 33 days of fetal life, with the appearance of first-order laminae. Second-, third-, and fourth-order laminae appeared at 39, 50, and 59 days, respectively. Neutral mucopolysaccharides first appeared in epithelial cells at 46 days of fetal life, decreasing quantitatively until birth, before subsequently stabilizing in postnatal life. Acid mucopolysaccharides, mucins, and mucoid compounds were not detected. Growth curves and formulas were constructed for each tissue layer. Initial tests involved multiplicative (y = axb), exponential (y = EXP [a + bx]), linear (y = a + bx), and polynomial models (y = a + bx + cx2 + dx3).

Development of meat and carcass quality characteristics in Iberian pigs reared outdoors.

A study of age-related changes in carcass traits and meat quality characteristics of Longissimus dorsi (LD) and Biceps femoris (BF) of free-ranged Iberian pigs was carried out to check whether the slaughter age used in the traditional management system of Iberian pigs is adequate. There was a great increase in live and carcass weight during fattening, principally due to an increase in fat deposition, as could be deduced from the percentage of dissectible fat and the backfat thickness. However, intramuscular fat in LD and BF showed only slight changes during the fattening. Myoglobin content tended to increase throughout lifetime in both muscles, whereas water-holding capacity decreased in intermediate ages and showed the highest values in the oldest animals. Total collagen content did not vary during lifetime; on the other hand, insoluble collagen increased from 7 to 77% of total collagen. It can be concluded that the traditional management system of Iberian pigs can be improved by fattening the pigs at a younger age, without negative consequences on the meat quality.

The influence of speed and height at the withers on the kinematics of sound horses at the hand-led trot.

The influence of speed and height at the withers on some biokinematic stride parameters (linear, temporal and angular) was measured in 15 Spanish Thoroughbreds (Andalusian Purebred) trotted hand-led along a track; analysis was made of the correlation between speed and height at the withers and of some biokinematic parameters of equine locomotion. Both height at the withers and speed were positively and significantly correlated to the linear parameters examined. Temporal parameters did not reveal a significant correlation with the height at the withers. The correlations with the angular parameters were variable, often being significant for both height at withers and speed, although in most cases the coefficient was relatively low, probably owing to the narrow ranges of speed and height at the withers and their low variability. It was concluded that horses at the hand-led trot tend to have low variability in speed during successive trials, although the speed at which they move does have a significant influence on both linear and temporal stride parameters, and also on several angular parameters, while height at the withers has a major effect on linear parameters but less on angular parameters, and does not affect the temporal parameters.

Morphometric changes in the dog trochlear nerve with growth.

The objective of this work was to analyse changes in morphometric characteristics related to growth in the trochlear nerve in dogs. Twenty beagles, split into four dog age groups (A, 7 days; B, 21 days; C, 35 days; D, 49 days and E, 4 years), were used. The right intracranial portion of the nerve was analysed by light and electron microscopy. The nerve cross-sectional area was calculated. Number, diameter and cross-sectional area of unmyelinated and myelinated fibres were also calculated. In myelinated fibres, the corresponding axon area and diameter and myelin sheath thickness were also calculated. The number of myelinated and unmyelinated fibres was 1070.25±112.07 and 592.25±467.53 in group A, 1367±57.98 and 143.67±54.37 in group B, 1574.20±299.50 and 151.67±51.73 in group C, 1340.33±151 and 127±48.75 in group D and 1476±260.71 and 284±101.82 in group E. The mean diameter for myelinated and unmyelinated fibres was 4.37±0.17 µm and 0.41±0.08 µm for group A; 6.21±0.12 µm and 0.30±0.03 µm for B; 6.90±0.91 µm and 0.32±0.03 µm for C; 7.86±1.19 µm and 0.32±0.02 µm for D; 10.63±0.50 µm and 0.30±0.01 µm for E, respectively. This nerve possesses similar structural and ultrastructural features to the same nerve in other species and modifies its morphometry with growth. Results could enhance the understanding of pathological disorders.

Purkinje cell apoptosis in arabian horses with cerebellar abiotrophy.

Purkinje cerebellar cells were studied in three Arabian horses aged between 6 and 8 months with clinical disorders in their movements, tremors and ataxia; the occurrence of apoptosis in this cell population was investigated by the (terminal deoxynucleotidyl transferase biotin-dUTP nick-end labelling (TUNEL) method. Both optical and electron microscopical images showed a scant number of Purkinje cells, most of them with morphological features of apoptosis such as condensation of the nucleus and cytoplasm as well as segregation and fragmentation of the nucleus into apoptotic bodies. The TUNEL technique revealed a substantial number (65%) of positive immunoreactive Purkinje cells.

Structural and ultrastructural study of the intracranial portion of the oculomotor, trochlear and abducent nerves in dog.

The right intracranial portion of the oculomotor, trochlear and abducent nerves were removed from six adult German shepherd dogs and analysed by light and electron microscopy. In all cases the nerve sectional area was calculated. Unmyelinated and myelinated fibres were analysed and number, diameter and cross-sectional area were calculated. In myelinated fibres, also calculated were the corresponding axon area and diameter, and myelin sheath thickness. The mean number of myelinated fibres was 8543.50 +/- 1231.85 being the unmyelinated 1402 +/- 241.58 in the oculomotor nerve; 1509 +/- 223.17 and 287.67 +/- 72.28 in the trochlear nerve and 2473.00 +/- 211.41 and 231.25 +/- 92.67 respectively in the abducent. The mean diameter was 10.23 +/- 0.68 microm in myelinated and 0.43 +/- 0.21 for unmyelinated in oculomotor nerve, 10.53 +/- 0.55 microm and 0.33 +/- 0.04 for the trochlear, and 10.45 +/- 1.27 microm and 0.47 +/- 0.09 in the abducent nerve respectively. This study reveals that oculomotor, trochlear and abducent nerves of the dog show structural and ultra-structural features similar to the same nerves in other species.

Morfometría del esófago abdominal y del estómago del conejo (Orycotolagus cuniculus): aplicaciones a la cirugía laparoscópica / Morphometry of the abdominal esophagus and stomach of the rabbit: laparoscopyc surgery applications

Actualmente existen pocos estudios sobre la anatomía y fisiología del tracto digestivo del conejo (Orycotolagus cuniculus), estos estudios están encaminados a la nutrición y biología del conejo, pero pocos abordan la anatomía con la visión de un cirujano. Por otro lado existen algunos estudios que proponen al conejo como modelo animal para cirugías laparoscópicas del esófago distal y el estómago. En la mayoría de los casos se utiliza como modelo sin tener en cuenta las características anatómicas específicas de esta especie, por lo que es fundamental realizar un estudio anatómico de la zona del esófago abdominal, cardias y estómago del conejo, que exprese las características y diferencias anatómicas para que los cirujanos estén más familiarizados antes de realizar prácticas laparoscópicas en esta especie. Una diferencia importante es la presencia de una porción grande de esófago abdominal. Está descrito que animales con porciones grandes de esófago abdominal, no tienen la posibilidad de regurgitar o vomitar. Esta diferencia anatómica es muy importante cuando se pretende usar a estos animales como modelo para la enfermedad por reflujo gastroesofágico (ERG).El presente trabajo se realiza con los objetivos de proporcionar a los cirujanos un estudio anatómico que permita conocer la zona del esófago abdominal, cardias y estómago del conejo, para que tengan conocimiento de las características propias en esta especie y las diferencias con el humano, en su uso como modelo animal para la cirugía del cardias y el estómago. Se realizaron medidas anatómicas al esófago y estómago de 18 conejos Nueva Zelanda Blancos de 2.5 a 3.5 Kg de peso de ambos sexos. Donde encontramos que el conejo presenta un una porción grande de esófago abdominal así como un estómago grande con una gran proporción de fundus gástrico.

Actuality, there are few studies about rabbits (Orycotolagus cuniculus) digestive tract anatomy and physiology. These studies are designed at nutrition and biology of the rabbit. But few deal with the anatomy of a surgeon's vision.There are also some researches that propose rabbits as laparoscopic surgery animal model for of the distal oesophagus and stomach. In most cases is used as a model without considering the specific anatomical characteristics of this species. So it is essential to make an anatomical study of the abdominal oesophagus, cardia, and stomach of the rabbit. This should express the characteristics and anatomical differences between species. On the way to that surgeon are more familiar before performing laparoscopic practices in this species. An important difference is the presence of a large portion of abdominal oesophagus. There is reported that animals with large portions of abdominal oesophagus, can not vomit or regurgitate. This anatomical difference is very important when trying to use these animals as a model for gastroesophageal reflux disease. This work is done with the objectives of providing surgeons an anatomical study of the abdominal esophagus, cardia and stomach of the rabbit, to have knowledge of the characteristics in this species and the differences with humans, when used as surgical animal model. Anatomical measures were made to the oesophagus and stomach of 18 males and females New Zealand White rabbits. Between 2,5 to 3,5 Kg. We find that the rabbit has a large portion of an abdominal oesophagus and a large stomach with a large proportion of gastric fundus.

[The development of the bovine stomach: morphologic and morphometric analysis. II. Observations of the morphogenesis associated with the omasum and abomasum]. / El desarrollo del estómago del vacuno: análisis desde el prisma morfológico y morfométrico. Parte II: Observaciones morfogénicas asociadas al bloque omaso-abomásico.

This study represents a continuation of part 1 of a study of the development of the bovine stomach. Material and methods are more fully described in part i of the study. In this part 2 of the study further developmental stages and morphometric analysis is presented.

[The development of the bovine stomach: morphologic and morphometric analysis. III. Spatial and morphometric reconstruction]. / El desarrollo del estómago del vacuno: análisis desde el prisma morfológico y morfométrico. Parte III: Reconstrucción espacial y morfometría.

This work represents a summary of the study presented in parts I and II, previously published in this journal. The data collected in those studies is presented in three dimensional reconstructions of the stomach of the developing calf.

[The development of the bovine stomach: morphological and morphometrical analysis. I. Morphogenic observations of the ruminoreticulum]. / El desarrollo del estómago del vacuno: análisis desde el prisma morfológico y morfométrico. Parte I: Observaciones morfogénicas asociadas al bloque ruminorreticular.

Forty-two embryos and fetuses of Frisian cattle, distributed onto 14 groups on the basis of crown-rump lengths between 1.3 cm (about 23 days) and 9.5 cm (70 days), were to study the morphogenesis of the bovine stomach. The work is divided into three parts. Part 1 deals with the ruminoreticulum and parts II and III the omasum and abomasum.

Variations in fibre size in the gastrocnemius muscle of rats undergoing training.

Sixty-six Wistar rats of both sexes were divided into six groups. One group was used as control, and the others underwent different training schedules. Muscle samples taken from the red and mixed portions of m. Gastrocnemius (caput lateralis) were stained with m-ATPase in order to identify fibre types I, IIA and IIB. These fibres were measured in order to determine their minimum diameter. The most notable results obtained were: a) the three types of fibre were generally larger in males than in females; b) the mean minimum diameter of fibres from the mixed portion was smaller than those of the red portion, except type IIB fibres, and c) the training schedules involved generally led to slight hypertrophy of all types of fibres, although this finding was more significant in the mixed portion of m. Gastrocnemius.