[Morphofunctional characteristics of interstitial endocrine cells (Leydig cells) from testis and prostate of Orenburg goats in ontogenesis and under conditions of seasonal changes in their reproductive activity]

Dynamics of structural reorganizations of goat testicular Leydig cells and prostate was monitored in different periods of ontogenesis using light and electron microscopy. Morphological equivalents of endocrinocyte functional activity elevations were noted within the period from d 60 to 70 of embryogenesis, at puberty and in mature animals before the onset of mating period in mature animals. Endocrinocyte foetal population destruction occurs by the 1st postnatal month. Leydig cell maximum activity peak precedes structural and functional differentiation in prostate both at stages of ontogenesis and in periods of seasonal oscillations of reproductive activity.

[Comparative histological investigations on the teats of sheep and goats]

In the present study the teats of the goat and the sheep were investigated light microscopically. In both species, smooth muscle elements condense towards the streak canal, and abundant arteries occur with thick tunica media and various valve structures. The apocrine sweat gland have a wide acinous element, which are regarded as a part of the excretory duct. Additional alveolar secretory tissue is present in the wall of the lactiferous sinus, which tubuloalveoli are probably of two varying types in the sheep and empty directly into the lumen of the lactiferous sinus in the goat. The histologic features of the teat in the goat differ mainly in the smaller and less coiled apocrine sweat glands, the thin stratum granulosum of the teat canal epithelium and the occurrence of supplementary canals (frequently two) in the initial part of the teat canal. The ovine teat shows a partly extremely thin epidermis, solid coiled apocrine sweat glands, and a pigmented epithelium of the teat canal equipped with a considerably thicker stratum granulosum.

Measurement of medullation in wool and mohair using an Optical Fibre Diameter Analyser

We conducted three experiments to evaluate the Optical Fibre Diameter Analyser (OFDA) for estimating medullation (med [M], kemp [K], and total [T] medullated fiber content) in mohair and wool produced by Angora goats and sheep, respectively. Medullation can be a beneficial characteristic in certain types of wool, but it is highly undesirable in mohair and apparel wools. Current techniques for evaluating medullation in animal fibers are laborious, slow, and expensive. The OFDA had been modified by the manufacturer to measure fiber opacity distribution, a characteristic known to be indicative of medullation in white fibers, and was capable of providing such measurements in a very short time. Measurements made on magnified fiber images produced with a projection microscope (PM) were used as a reference for M, K, and T in fiber samples. An initial experiment with 124 mohair samples (T = .10 to 9.10%) seemed to indicate that OFDA estimates of M, K, and T were only poorly correlated with corresponding PM values (r2 = .5409, .1401, and .5576, respectively). However, a second experiment using wool and mohair samples containing a wider range of medullation (T = .58 to 26.54%) revealed that OFDA estimates of M, K, and T for wool were highly correlated with PM measurements (r2 = .9853, .9307, and .9728, respectively). Evidence was also obtained indicating that the low r2 values associated with mohair relationships were likely due to a combination of factors: 1) high variation among the standard PM measurements and 2) the relatively low M, K, and T contents of the mohair samples compared with wool. In a third experiment, greater accuracy was obtained in the PM measurements by evaluating many more individual fibers per sample (10,000). In this case, OFDA estimates of M, K, and T for mohair were highly correlated with corresponding PM measurements (r2 = .8601, .9939, and .9696, respectively). However, the two sets of linear regression equations obtained for wool and mohair were somewhat different, indicating that separate calculations should be used to estimate PM measurements from OFDA data. In conclusion, it was demonstrated that the OFDA instrument is capable of providing relatively fast, accurate, and potentially less expensive estimates of medullated fiber characteristics in mohair and wool.

Morphological study of the forestomach of the Japanese serow (Capricornis crispus)

Details of the morphology of the forestomach of the Japanese serow (Capricornis crispus) were examined macroscopically, and by light and scanning electron microscopy. The rumen was sac-like in shape, and the right accessory longitudinal groove was not visible externally. The reticulum was relatively small, while the omasum was oval and large. Inside the rumen, even in the dorsal sac, the ruminal papillae were densely distributed, although absent on the pillars. The caudodorsal coronary pillar was indistinct. In the ruminoreticular fold, ruminal papillae were observed even on the reticulum side. In the reticulum, the primary reticular fold was apparent and the ill-defined secondary folds were also detected in some reticular cells. In the omasum, the omasal laminae of four sizes were recognized. The fourth order of laminae was occasionally absent. Histological sections of ruminal papillae revealed that softly keratinized epithelium covered the entire ruminal mucosa. In the reticulum, soft keratinized epithelium was observed throughout, with the exception of the tips of reticular papillae on which the epithelium showed evidence of hard keratinization. The epithelium of the omasal laminae was moderately keratinized. On the floor of the reticular groove, interlaminar area and in the omasal groove, the accumulations of numerous eosinophilic cells were observed in the superficial region. Under the scanning electron microscope, shallow transverse grooves were seen on the surface of the ruminal papillae. In general, the surface structure seemed to be similar to that of sheep rather than cattle. Cellular formations of the collagen fibrils were observed at the subepithelial region. In conclusion, examination of the forestomach allows classification of the Japanese serows as requiring an intermediate type of feeding habit and being between concentrate selectors and grass-roughage eaters from a morphological view.

Morphology of the tongue of a male Formosan serow (Capricornis crispus swinhoei)

The morphology of the tongue of an adult Formosan serow was examined to compare it with that of the Japanese serow by macroscopical and scanning electron microscopical observations. The tongue was 13.5 cm in length and 82 g in weight. The apex showed a U-shaped outline. There were 340 fungiform papillae and 23 vallate papillae on both sides. Filiform, fungiform, conical and vallate papillae were found. Annular pads surrounding the vallate papillae were poorly developed. No lenticular or foliate papillae were seen on the dorsal surface. These findings indicate that the tongue of the Formosan serow is smaller and less complex morphologically than that of the Japanese serow.

Ultrastructural and freeze fracture cilia morphology of trachea epithelium in apparently healthy small ruminants

Specimens of tracheal mucosa were obtained from ten adult apparently healthy small ruminants (five goats and five sheep) both by a fibre optic endoscope and in a slaughterhouse. Ultrastructurally, a total of 50,000 cilia were examined. Pathological cilia were found in all examined subjects. The prevalence of compound cilia showed a range of 0.3% to 3%. Intracytoplasmic and swollen cilia ranged from 0.2% to 0.5%. The microtubular pattern was examined in 4,000 cross-sectioned cilia and an abnormal pattern was found in 5-7%. Microtubular defects involved both peripheral and central doublets, being peripheral abnormalities the prevailing ones. A central plug of electron dense material was observed in 2-3% of the examined basal bodies. Rare basal bodies characterized by an abnormal spatial configuration were also shown. Freeze fracture studies revealed a ciliary necklace composed of 4 to 5 rows of intramembrane particles.

Anatomy of the cranioencephalic structures of the goat (Capra hircus L.) by imaging techniques: a computerized tomographic study

A topographic study of the cranioencephalic structure was carried out by computerized tomography on Canarian breed adult goats of medium size and weight, with similar cephalic parameters. In this way, transversal, sagittal and horizontal tomographic images were obtained. Identification of the observed anatomic structures represents the basis of this work from which applicable specie data are derived.

[Anatomo-radiologic correlation of the head of the goat of the canary breed (Capra hircus L.)]

A radiologic and tomographic study was made of the cranioencephalic topography of canary goats of medium weight and size. In a first step, the exocranialis references corresponding to an axis designed at the level of the meatus acusticus externus and parallel to the basicranial axis were anatomically and radiologically defined. Conventional stereotaxic techniques were then used to reach the standard position of the head in order to obtain macroscopical cross sections at different levels perpendicular to the base of the cranium. In a second step, a tomographic study was made to confirm the design of the axis.

Immunohistochemical localization of corticotropin-releasing factor, [arginine8]-vasopressin and oxytocin neurons in the goat hypothalamus

Distribution patterns of corticotropin-releasing factor (CRF), [arginine8]-vasopressin (AVP) and oxytocin (OXY) neurons were examined immunohistochemically in the female goat hypothalamus. The majority of the CRF immunoreactive (-IR) cells were located in the parvocellular part of the paraventricular nucleus (PVN) with smaller population found in the magnocellular part of the PVN. CRF-IR cells were also found in the suprachiasmatic nucleus, the preoptic area and around the fornix in the caudal part of the hypothalamus. AVP- and OXY-IR cells were similarly distributed in the hypothalamus. The majority of AVP- and OXY-IR cells were observed in the magnocellular part of PVN and the supraoptic nucleus. Smaller numbers of AVP- and OXY-IR cells were found in the parvocellular part of the PVN and lateral hypothalamic area. AVP-IR but not OXY-IR cells were located in the suprachiasmatic nucleus. CRF-IR fibers were concentrated in the external palisade zone of the median eminence (ME) with a few fibers found in the internal palisade zone of the ME, whereas AVP- and OXY-IR fibers were concentrated in the internal palisade zone of the ME with a few fibers found in the external zone. These results support the view that not only CRF but also AVP and OXY are released into the hypophysial portal blood and involved in the control of pituitary endocrine function in ruminant species.

Transmission electron microscopy of the epithelium of distal airways and pulmonary parenchyma of the goat lung

Lungs from eight goats of mixed sexes and breeds (Cashmere, Nubian and Toggenburg) aged between 10 and 48 months were used in this study. Tissues from lung parenchyma were minced and routinely prepared for transmission electron microscopy (TEM) after using different methods of fixation. Thick sections were examined with a light microscope and samples, to include terminal bronchioles, respiratory bronchioles, alveolar ducts and alveolar membrane, were selected for ultrathin sectioning. Six cell types, ciliated, non-ciliated bronchiolar epithelial, mucus-producing, alveolar Type I, alveolar Type II and capillary endothelial cell were identified and characterised cytologically. It was established that the cell population in the distal airways is similar to that observed in other domestic mammals. The mucus-producing cell, which appears to be a common cell type in the distal airways of man and Rhesus monkey, was encountered particularly in adult goats in the present study. This study has also established that the Clara cell of the goat shows some cytological differences from those of some other mammalian species by having a large amount of SER, particularly in the apical region. Lipid vacuoles were seen to be a feature of the alveolar Type II cells; these do not appear to have been reported in other mammalian species. The study has provided a basic understanding of the morphological features of the cell population of the epithelium lining the distal airways in the goat's respiratory tract. The difference in junctional complexes between the various alveolar epithelial cells perhaps signify a different pattern of intercellular transport, thus influencing the pathogenesis and resolution of alveolar pulmonary edema.

[Development, cytoarchitecture and ultrastructure of the mesencephalic trigeminal nucleus in domestic ruminants]

The ontogenetic development and cell differentiation of the mesencephalic trigeminal nucleus (Ntm) is lightmicroscopically examined in 58 bovine embryos and fetuses ranging from 2.4 to 80 cm Crown-Rump-Length (CRL). The cytoarchitecture and fine structure in adult cattle, sheep, and goats are investigated with the aid of light- and electronmicroscopy. At 2.4 cm CRL, the proneurons of the Ntm are detectable for the first time within the ventricular zone of the alar plate, possessing one drop-like cytoplasmic protrusion, whereas at 5 cm CRL, two cell types with differing sizes appear. Up to a CRL of 11.5 cm, the nucleus shows advanced maturation processes and has reached his final position at the border of the mesencephalic central grey. From 26 cm CRL onward, three cell types, and at 34 cm CRL four cell types, are discernible based on their nissl-granule arrangement. The cytomorphological differentiation and the maturation of the cells proceeds until 56 cm CRL, at which point the topographical and cytological characteristics of the Ntm are comparable with those of adult animals. In adult cattle, sheep and goats the Ntm consists of large (40-60 microns) and scarce medium-sized (30-40 microns) neurons with round and oval shapes. Scarcer small (20-25 microns) round and medium-sized multipolar neurons occur. The Nissl bodies are scattered throughout the pericaryon of the large neurons in a dust-like pattern and in the medium-sized neurons in a grained form. Within the cytoplasmic streets, which are situated between the membranes of the rough ER, numerous neurofilaments and mitochondria are detectable. Large Golgi complexes are placed in a perinuclear position. The neurons are also characterized by some somatic spines, and by a moderate distribution of axosomatic synapses, in which axon-endings with flattened synaptic vesicles predominate.

Estimation of liveweight from chest girth in pure and crossbred west African goats

Linear and geometric regression equations were used to estimate liveweight from chest girth in 78 West African Dwarf and 73 Sahel x West African Dwarf goats. The coefficients of determination (R2) ranged from 0.87 to 0.92 and 0.97 to 0.99 for linear and geometric equations respectively. There were no significant breed or sex differences in the R2 values of the equations. The geometric equations estimated liveweight with a high degree of reliability regardless of girth size whilst the linear equations yielded very low and frequently negative liveweight estimates where girth measurements were below 30 centimetres.

A quantitative study of ganglion cells in the goat retina

As in a number of mammals, the most prominent feature of the ganglion-cell layer in the retina of the murciano-granadina goat is an increase in the density of ganglion cells in the central area, as well as a concentration along a ridge extending horizontally across the retina, below the optic disc, and in the upper temporal retina. Thus, there is an area of maximum density and two streaks that are known as the 'horizontal' and 'vertical' streak. The isodensity lines of ganglion-cell distribution is toughly concentric, with their values varying from 304 cells/mm2 in the periphery to 3592 cells/mm2 in the central area, with the cells densely packed. There were some individual differences amongst the animal studied, although all of them were purebred animals.

The surface morphology of the omasum of the African goat

The microstructure of the omasum of the African goat was investigated macroscopically, as well as by scanning electron microscopy to determine how the omasum is anatomically specialised to enable the goat to graze and browse so successfully in the harsh environments of Africa. The omasum of the African goat was found to be more simple in structure than that of other domesticated ruminants. The omasal laminae were arranged in only 3 orders with the number of laminae varying between 27 and 33, considerably fewer than previously described for other goats, sheep or cattle. The large conical and unguiculiform papillae surrounding the reticulo-omasal orifice, as well as the hooked papillae present on the laminae, were more similar to those of wild ruminants that browsed than domestic grazing species. The papillae on the laminae were also found to be directionally orientated towards the orifices, which may suggest a "sieve mechanism' at the reticulo-omasal orifice and interlaminar spaces. In addition, it may suggest a directional movement of ingesta between the laminae. The stratified squamous epithelium lining the laminae and papillae was lightly keratinised which, along with the microplicae-like surface folds and pits of the superficial cells, indicated that it was functionally structured for absorption. These morphological specialisations of the omasal surfaces of the indigenous African goat demonstrated similarities with that of wild ruminants that are able to graze and browse.

Cephalad distribution of three differing volumes of new methylene blue injected into the epidural space in adult goats

Epidural anesthesia and analgesia are popular regional anesthetic techniques in many animal species. However, we have not found any reports of studies in animals that have investigated the extent of cephalad migration and level of sensory blockade achieved based only on the volume of drug injected into the epidural space. The purpose of this study was to determine if there is a relationship between the volume (mL/kg) of an injectate injected epidurally and the extent of its cephalad migration within the epidural space. Twelve adult goats were randomly assigned to three treatment groups based on the volume of 0.12% New Methylene Blue (NMB), 0.1, 0.2, or 0.3 mL/kg, injected into the epidural space. The site and speed of injection, animal position, and direction of needle bevel were held constant. All injections were performed at the lumbo-sacral space immediately following euthanasia. At necropsy, the vertebral columns were transected longitudinally. The extent of cephalad migration of dye within the epidural space was easily determined by staining of the dura. Measurements were rounded to the nearest intervertebral space to which the dye had migrated. The individual making assessments was blinded to all treatments. In goats treated with 0.1, 0.2, or 0.3 mL/kg NMB, the number of stained spinal segments was 3.5 +/- 0.6, 6.5 +/- 0.9, and 8.8 +/- 0.6, (mean +/- SEM), respectively. Linear regression performed on the data was significant (P < .05) with R2 = 0.86. There was a strong linear relationship between volume (mL/kg) of epidurally injected NMB and cranial migration, with the larger volumes producing more cephalad spread within the epidural space. These results provide evidence for the volume of epidural injectate needed to produce a desired level of sensory blockade in adult goats.

Seasonal variation in the correlation of testicular and epididymal weight-dimensions in the red Sokoto goat and white Yankassa ram

A correlative study of testicular weight (TW), length (TL), diameter (TD), epididymal weight (EW) and cauda epididymal weight (CEW) in adult red Sokoto goat and white Yankassa ram during the dry and wet seasons in Kano City, Nigeria was undertaken. The data was analyzed by Pearson's product of moment correlation coefficient and the results showed that TW maintained a highly significant correlation with TL, TD, TW and CEW in the ram, and goat during the wet season (p < 0.01), but non-significant correlation with TL and TD during the dry season (p > 0.05). This suggests that there is a seasonal variation in the dimensions of the reproductive organs of the animals and that during the breeding season (wet season) testicular size and weight are intimately correlated. During the wet season, the reproductive performance of these animals may be assessed by measuring their testicular size and will be very useful in animal husbandry.

On the vegetative and sensitive innervation of the Retractor clitoridis muscle in some domestic animals

The retractor clitoridis muscle originates from the coccygeal vertebrae in the cow, ewe, goat and mare, and from the anal musculature in the sow. It terminates at the base of the clitoris. In all the species considered, a vegetative innervation was found. This was represented by isolated or grouped ganglion cells. Nervous sensitive supply was also present. This was represented by Pacinian, Pacinian-like and Golgi-Mazzoni's corpuscles, and by Krauses's end bulbs. A notable difference was found in the amount and type of these receptors. They were numerous in the sow, ewe and goat, and rare in the cow and mare. Additionally, in the sow, ewe and goat, all the above mentioned receptors were found, while, in the cow and mare, only Pacinian and Pacinian-like corpuscles occurred. The morphology of these receptors was described and hypotheses were made concerning their probable functional role.

Morphology of the interdigital glands of a Formosan serow (Capricornis crispus swinhoei)

The morphology of the interdigital glands of a male 9-year-old Formosan serow was examined. The glands were sock-shaped depression of the skin and were present in four feet. The glands were composed of a neck and a body. The epidermis of inner wall of the glands was keratinized stratified squamous epithelium. Apocrine glands were developed, while the sebaceous glands and hair follicles were very poorly developed. Contents, probably dirt, were small in the interdigital glands. These findings resemble to the interdigital glands of the Japanese serow and suggest that the interdigital glands have very low activity of secretion.

Ultrastructure of the carotid body of the goat

The carotid body of the goat was found to be a small oval or rounded parenchymatous organ. It was characterized by its profound vascularity. Delicate septa divided the parenchyma into small feebly defined lobules. Electron microscopy revealed that the parenchyma comprised type I cells, type II cells, nerve endings, axons and fenestrated dilated capillaries. Type I cells were characterized with electron dense-cored vesicles. They showed variations in size and concentration of the dense-cored vesicles and number of mitochondria. The possibility that these variations are reflections of different stages of activity is discussed. Type II cells were less numerous than type I cells, relatively small and devoid of dense-cored vesicles. They usually surrounded small groups of type I cells and associated nerve endings and axons. Presumptive afferent nerve endings characterized with many clear vesicles, occasional large granular vesicles and varying numbers of slender mitochondria, lay apposed to type I cells. Nerve endings of this kind showed afferent and efferent synaptic junctions with type I cells. Presumptive sympathetic efferent endings were occasionally seen within the lobules but never lay apposed to type I cells or afferent nerve ending.

[Intramural blood vessel system of the large intestine of domestic ruminants]

The vascular system of the large intestine of 15 cattle, 10 sheep and 5 goats has been examined by means of corrosion vascular casts, histology and electron microscopy. The results are as follows: The course and ramification of the intestinal vessels are identical in the caecum, colon and rectum. Furthermore, as expected, amongst the species studied no substantial differences in the vascular architecture of the large intestinal wall could be determined. The extramural vessels reach the wall of the intestine at the mesenteric margin. Their branches build arterial or venous networks in the tela subserosa, which then divide into branches in the direction of the antimesenteric region. The connections between the blood vessels of the tela subserosa and the tela submucosa as well as the branches to the muscular layers emerge from these networks. In the tela submucosa an arterial and venous system can be found. The obvious vascular arrangement in the submucosa is arranged not only parallel to the stratum circulare of the tunica muscularis but also along the prevailing direction of the lamina muscularis mucosae. From this arrangement both a deep and a superficial submucosal vascular plexus can be denominated. The recurrent branches for the circular muscle layer as well as the afferent and efferent vessels of the mucosa originate from submucosal arteries and veins. The arterioles of the tunica mucosa branch at the level of the basal crypts into a periglandular capillary system running close to the lumen into a subepithelial capillary system. Here the capillaries drain into venules which advance to the region of the intestinal glands and consequently drain into collecting veins in the submucosa. Capillaries of the subepithelial lamina propria mucosae are furnished with continuous or fenestrated endothelial linings as the morphological equivalent of the secretory or resorption processes, respectively. In the walls of the large intestine of the bovine, sheep and goat there are neither arterio-venous anastomoses nor hemodynamic regulatory structures such as sphincters or so-called throttle veins at the points of transition from capillaries to venules. These results are in accord with the findings in the small intestine of domestic ruminants (Hummel 1980).

Hypothalamic structures of the goat on stereotaxic coordinates

Serial brain sections of 50 microns thickness were made from celloidin embedded brains taken from adult male goats. They were stained by means of cresyl violet either with or without luxol fast blue, and the cellular and fiber patterns were examined both macro- and microscopically. Brain sections were transferred on to scanner and their images were recorded by computer. The brain maps were made with the aid of appropriate software and presented as a series of coronal graphics of the hypothalamus that cover the area from the mammillary tubercles to the level of the optic chiasm. The thalamus and the amygdala were also included. Reduction of the brain tissue during the histological procedure was analyzed by means of coronal and sagittal scanning by computer tomography (CT) imaging. It was related to the proportion of the gray and white matters in the encephalic area. The hypothalamus showed an 11% shrinkage. The stereotaxic location of the hypothalamic nuclei was estimated by compensating for the reduction rate of the area. The stereotaxic coordinates developed for goat brain were easy to apply and transfer to the computer coordinate system.

Cranial and cerebral-ventricular landmarks for accurate stereotaxic approach to hypothalamic nuclei in the goat brain

This paper describes a new stereotaxic coordinate system for the goat brain based on cranial landmarks. An osseous triangle (a-b-c) formed by the point of junction of the crista galli with the caudal ventral part of the frontal sinus septum (a), the external occipital protuberance (b), and the midsagittal projection of the external acoustic meatus (c), was measured using lateral radiographs and ventriculographs and showed a constant mathematical relation. The rostral angle was 20.3 +/- 1.0 (mean +/- SD) degree in 23 goats studied regardless of their cranial size which varied considerably from one animal to another. The hypotenuse length (a-b distance) was found to be a good predictor of the rostral nuchal position of the anterior commissure (AC) and the infundibular recess of the third ventricle (INF), by which the individual variance of the stereotaxic coordinates for a given hypothalamic structure could be compensated. The anterior-posterior distances from the external acoustic meatus was highly correlated with the a-b distance for AC (r = 0.88) and INF (r = 0.90). Using these cranial landmarks and the method outlined in this paper, uncertainty in coordinate values for AC and INF in the goat brain was reduced considerably in comparison to deviation observed when the ordinary Horsley-Clarke axis (Reid's plane) was employed.