Comparative structure and morphology of the goat sternum in West African dwarf and Danish Landrace breeds

The structure and morphology of the sternum from 33 West African dwarf (WAD) and sixteen Danish Landrace breed goats were studied radiographically. In young kids of the Danish Landrace breed (DL), the number of sternal elements (Sternebrae) was six or seven with the fifth or the last but one being double in some animals due to bilateral bodies. All the sternal elements in the WAD breed appeared to have each a single locus of ossification and the number of sternal elements varied between 5, 6 or 7 at birth. In those goats with 5 or 6 sternal segments, bilateral indentations were observed on the left and right side on either the last or the last two segments. These indentations were considered to indicate a prenatal cranial coalescence of the last segments leading to the reduced number of sternebra. The structure and morphology of the sternum in neonatal kids for the two breeds appears to be basically different. 8 sternal and 5 asternal ribs were observed in animals of both breeds. The cartilaginous attachments of the ribs on the sternal segments were variable. A floating rib was also observed in one of the WAD goats. The comparative structure and morphology of other ruminant sternum is also discussed.

Reexamination of the morphology of the extratesticular rete and ductuli efferentes in the goat

The morphology of the extratesticular rete and ductuli efferentes was reexamined in serial cross sections collected from the entire mass of the efferent ductules and in longitudinal sections collected from the partially unraveled efferent ductules. The extratesticular rete forms a 3-4-mm-long sac-like dilatation, which, within the head of the epididymis, has a wide lumen (up to 4 mm) and gives off along its length numerous evaginations, which, in turn, make connections with the ductuli efferentes. The latter is a mass of 16-18 ductules lined by three types of nonciliated cells: type II cells are characterized by dense, periodic acid-Schiff (PAS)-positive granules; type III cells are characterized by empty-appearing, PAS-negative vacuoles; and type I cells lack both granules and vacuoles. The distribution of the three types of nonciliated cells varies along the length. Whereas only type I cells are present in the beginning portion of the efferent ductule, type II cells predominate in the middle portion and type III cells in the distal portion (near the epididymis). The transition from one cell type to the other type is gradual; thus there are short segments along the length that share characteristics first for type I and type II cells and then for type II and type III cells. These results demonstrate that different nonciliated cell types are not randomly distributed in the epithelium of the ductuli efferentes but, instead, gradually differentiate from type I to type II to type III cells along the length of each efferent ductule. Factors controlling this differentiation remain to be studied.

B-mode ultrasonography of mammary glands of cows, goats and sheep during alpha- and beta-adrenergic agonist and oxytocin administration

Teat and gland cistern of the mammary glands of five dairy cows, five goats and five sheep were scanned in a water bath during alpha- and beta-adrenergic agonist and oxytocin administration. A 5 MHz linear array scanner was used to create vertical cut pictures with the scan plane longitudinally through the teat channel. The i.v. injection of the alpha-adrenergic agonist phenylephrine (30 micrograms/kg) induced diminution of the section area through teat and gland cistern by 38 +/- 17% on average within 1 min in all three species. In contrast, the i.v. injection of the beta-adrenergic agonist isoproterenol (1 microgram/kg) did not change the cisternal areas. The i.v. injection of oxytocin (2.0 x 10(-3) i.u./kg) elicited an enlargement of teat and gland cistern area by 48 +/- 12% on average. Ultrasonography proved to be a valuable system for visualizing changes of the cisternal volume. Smooth muscle contractions in response to phenylephrine administration are thought to cause area reduction, whereas an expected smooth muscle relaxation after injection of isoproterenol could not be observed by ultrasonography. Milk ejection as induced by oxytocin administration caused dramatic enlargement of the cistern area in all three species.

Ultrastructure of goat testes: intercellular bridge between germ cells

The fine structure of intercellular bridge (ICB) of goat germ cells was studied using testicular samples fixed by perfusion. In the seminiferous tubules, the ICBs were observed between sister cells of spermatogonia, spermatocytes and spermatids. As a result of incomplete division of germ cells, the ICB first appeared as a midbody containing a remnant of the bundle of microtubules (spindle fibers). These microtubules then disappeared and were replaced by a shutter apparatus which was composed of multiple lamellar cisternae (bridge-partitioning complex). The inner part of the ICB was reinforced with a layer of electron dense mass (bridge density) which persisted up to the residual cytoplasm of spermiation. After complete reconstruction of the sister cells, the cisternae of the bridge-partitioning complex disappeared and the channel of the ICB was opened. Evidently (see electron micrographs), almost all of the cytoplasmic organelles could pass through the channel of the ICB. In the longitudinal section, the appearance of the ICBs between sister spermatogonia and between sister spermatocytes was observed as a double linear or drum shape, and that between sister spermatids was noticed as a horseshoe-like or concave formation. With the process of spermatogenesis, the ICBs gradually became widened and shortened. The functional significance of the ICB in the goat was discussed.

The apical ligaments of the penis of the goat and sheep

The penile apical ligaments of 13 goats and 8 sheep were dissected and described. Unlike the single apical ligament of the bull penis, both goats and sheep had one ligament on each side of the apex of the penis with no apparent connection over the dorsal surface. These lateral apical ligaments consisted of substantial connective tissue fibers that arose from the outer layers of the tunica albuginea and varied from 6.0 to 10.0 cm in length. The left apical ligament was longer and thicker than the right. The left apical ligament of the sheep penis was divided into a dorsal and a ventral branch. Both the goat and sheep possessed flattened perivenous ligaments that originated from the apical fascia and extended caudally along each side of the dorsal vein of the penis.

Ependyma of the goat. Part IV. Ependymal lining of the median eminence in goats under physiological and experimental conditions

The sexual differentiation of the ME ependymal lining surface structure has been proved in goats. Suitable hormonal preparations applied to females during anestrus induced on the median eminence the same picture as that during estrus. Only after gonadectomy in both the females and males there were dense macrophages-like SEC on the ME protruding from the deeper layers of the eminence. Their potential function is discussed.

[The fine structure of the nucleus of the hypoglossal nerve of sheep and goats]

In the small domesticated ruminants the nucleus of the hypoglossal nerve is situated in close relationship to the median line in the middle of the elongated medulla. The nucleus is divided by the obex into a rostral and a caudal portion. In the sheep, four distinct subnuclei can be recognized, whereas in the dwarf goat great variations in the arrangement of cell groups exists. In both animals large and medium sized neurons are observed. The large neurons are characterized by densely packed small organelles. The medium sized neurons vary between a pale and an electron dense type. According to the size and morphology of the vesicles three types of synaptic contacts can be differentiated. Synapses of type 2 contain clear round and flattened vesicles and are partially accompanied by subsurface cisterns.

[Microscopic studies of the skin of the Turkish angora goat. II. Functional morphology of the hair follicle]

The study supplies a detailed description of the development, morphology and function of anagen hair follicles in the Turkish Angora goat. In this connection, the formation of the hair root and the epithelial root sheaths is of specific interest. Furthermore, the intensive structural alterations and disintegrative processes occurring during the catagen phase are presented. The telogen hair follicle development is also referred to with special regard to typical structural and functional features.

Accurate prediction of Purkinje cell number from cerebellar weight can be achieved with the fractionator

Purkinje cell nucleoli are used as counting units in order to obtain unbiased (fractionator) estimates of the number, N, of Purkinje neurons in adult mammalian cerebella of known weight, W. Regression analysis is then employed to establish the nature of the relationship between logN and logW. The linear regression equation defines an allometric relation that is employed to predict number in cerebella of known weight from other mammals. Predicted numbers are tested against empirical estimates. For 19 cerebella ranging in weight from 0.2 g (rat) to 113 g (human), the allometric relation between Purkinje cell number and organ weight was determined. By using this relation, the mean complement in three rabbit cerebella (average weight, 0.87 g) is predicted to be 0.63 million. This figure is confirmed by fractionator estimates made on the same three brains. The cat cerebellum should contain about 1.5-2.0 million Purkinje cells. An estimate of 1.2-1.3 million cells is to be found in the literature. Including rabbit cerebella in a refined equation yields the following relation: N = 686000W(0.695). With this refined equation, further predictions are made about the numbers likely to be found in the cerebella of the dog, goat, pig, ox, and horse. The numbers predicted for these animals must await experimental verification, but they are entirely consistent with previous suggestions that neuronal packing densities decrease with increasing brain size.

Spinal cord mensuration--a comparative study on the spinal cord segments and spinal nerves in Zambian goats

It has been known that the relative length of spinal cord and its segmental volume in domestic animals has established that the dynamics of spinal cord is directly related with the functions of the limbs and in particular to their feeding habits. Bilateral rostrocaudal measurements of spinal nerves involving their root attachment length, root emergence length, interroot length, segment length and cross sectional area were recorded on the dorsal and ventral surfaces of each segment of the spinal cords of five local healthy Zambian goats. We identified that the brachial and lumbar enlargements have involved identical number of spinal cord segments. Brachial and lumbar enlargements extended from C6 to T1 and L4 to L7. The average length of spinal cord was 59.9 cm and it extended up to caudal end of 5th sacral vertebrae. The root emergence length appeared to decrease gradually from C2 segment, which remained less variable in thoracic and lumbar segments and then receded sharply through sacral segments. The dorsal nerves entered spinal cord over a greater area than ventral because of more spinal rootlets. The greatest segment length lied in mid cervical region and then from lumbar segment it decreased sharply up to the end of sacral segments. It is concluded that these goats have a feeding habit similar to that of cattle rather than resting their forelimbs on the shrubs while nibbling the leaves as recorded in Asian goats. It also confirmed that the shrubs were more drooping along with grasses in the Gwembe Valley of Zambia.

B-mode real time ultrasonographic imaging of the testis and epididymis of sheep and goats

Ten male goats and five rams were examined from 11 and 15 weeks of age, respectively, for six months to study the ultrasonic appearance of normal testes and epididymides before and after puberty. Five adult rams with lesions of these organs were also examined. A portable, B-mode, real time scanner fitted with a 7.5 MHz, linear array transducer was used. The testis appeared as a homogeneous and moderately echogenic structure with a centrally located mediastinum testis represented by an hyperechogenic line in images taken in the longitudinal plane and by an almost circular spot in transverse images. The testicular capsule and skin were evident as a distinct hyperechogenic line encircling the testicular parenchyma. A thin non-echogenic layer of fluid, presumably between two layers of tunica vaginalis, was observed. The tail of the epididymis was more heterogeneous and less echogenic than the testis. The epididymal head was also less echogenic but homogeneous in texture, and the body of the epididymis was difficult to image. The pampiniform plexus was easily identified as numerous convoluted sonolucent tubular structures. The ultrasonic images of possible cases of epididymitis, spermatocele, testicular cyst and abscess and scrotal hernia are described.

Regional differences in the morphology of the goat epididymis: a light microscopic and ultrastructural study

The goat epididymis, based on morphological differences, was divided into five regions; regions I and II, and the proximal part of region III constituted the head; the distal part of region III and region IV, the body; and region V, the tail. The epithelium of all regions contained principal and basal epithelial cells and intraepithelial lymphocytes and macrophages. In addition, regions II to IV also contained a few apical cells. Clear cells were absent. The epithelium varied in height from the tallest in region I (88 +/- 33 microns) to the shortest in region V (38 +/- 5 microns). Conversely, the luminal diameter, thickness of smooth muscle wall, and luminal sperm concentration were highest in region V. The irregular epithelial height of regions I and IV accounted for a stellate lumen in contrast to the oval lumen of the other regions. Whereas the lumen of region I contained only a few sperm, those of regions II, III, and IV were filled with sperm. Principal cells were the only cell type that showed striking cytological differences between regions. While they contained absorptive features (canaliculi, pinocytotic and coated vesicles, and subapical vacuoles) in all regions, the principal cells of region II were filled with large, heterogeneous vacuoles (up to 5 microns in diameter), suggesting that they may be preferentially involved in transporting and digesting particulate material. Besides absorptive features, principal cells of all regions contained morphological correlates of protein synthesis such as highly developed Golgi complexes in the supranuclear area and numerous cisternae of RER near the Golgi body and in the infranuclear cytoplasm. The cisternae of RER were more developed in region IV, and in some instances, they were distended with flocculent material resembling newly synthesized protein. Unlike the protein synthesizing organelles, principal cells of all regions lacked morphological correlates of steroid hormone synthesis. These results are compared with previously published data on the regional differences in the epididymis of other species, especially with those of the rat and the bull, in an effort to understand the significance of the epididymis in sperm maturation.

On the a. malaris of the goat (Capra hircus)

Detailed observations were made of the a. malaris in 25 adult goats by means of the acryl plastic injection method and the findings obtained were evaluated in comparison with those for other mammals. The malar artery arose from the superior wall of the infraorbital artery, lateral to the infraorbital nerve and superomedial to the maxillary tuber, independently or rarely in common with the superior alveolar artery. It first passed anterolaterally in the sulcus malaris on the superior surface of the lacrimal bulla and gave rise to the third palpebral branch independently or rarely in common with the inferior oblique muscular branch beneath the obliquus inferior muscle, and also the main and accessory inferior oblique and the maxillary sinus branches. The third palpebral branch gave off the periosteal, the conjunctive, the supero- and inferolateral branches. After the malar artery gave off the zygomatic branch on the orbital surface of the zygomatic bone, it passed anterosuperiorly up to the incisura malaris at the medial end of the infraorbital margin of the lacrimal bone and gave off the medial superior and inferior palpebral arteries or a common trunk between them. It continued to pass forwards as the nasal radical branch after giving off the infraorbital marginal branch and anastomosed with the nasal dorsal branch of the superficial temporal artery. The medial inferior palpebral artery formed the inferior palpebral arterial arch by anastomosing with the lateral inferior palpebral artery of the superficial temporal at the lateral canthus. The inferior palpebral marginal, the ocular orbicular muscular and the conjunctive branches diverged from the above arterial arch. The medial superior palpebral artery gave off the lacrimal canalicular and the nasolacrimal canal branches and anastomosed with the lateral superior palpebral artery or the frontal branch of the superficial temporal at the medial canthus. The characteristic features of the malar artery in the goat were thus the third palpebral branch occasionally diverging from the external ophthalmic artery of the maxillary artery, a main and several accessory inferior oblique muscular, the maxillary sinus branches and the zygomatic branches.

Binocular dissecting microscopic studies on the density of toruli tactile in the La Mancha goat

The Merkel cells and associated nervous terminal plates have been called toruli tactiles (TT). These structures can be ubiquitously seen on the shaved hairy skin after staining with a methylene blue solution. Four La Mancha goats of both sexes were examined for the density of TT. TT were visually located under a binocular dissecting microscopic (14x) and then the number of TT in the field was directly counted. The density of TT in different corporal areas of the body surface was estimated from the mean of several two-cm square samples of skin. The results obtained are as follows: The mean number per two-cm square on the whole body surface ranged from 10.06-11.36 in the male specimen and from 12.98-14.32 in the female specimen. The density of TT was rather high in the temporal and buccal areas, on the neck, chin and cranial breast, and on the lateral surface of the arm, thigh and leg. Density was moderate in the fronto-parieto-occipital area (female), on the loin and buttocks, in the upper costal, lower caudo-costal, xiphoid-umbilical and umbilical-pubic areas, and on the lateral surface of the forearm. TT were absent or very few in number on the nose and chin, the scrotum, caudal-pubic area of males, the udder, the vulva, and the digitorum manus et pedis.

Histo- and cytochemical studies on the distribution of acetylcholinesterase-positive nerve fibers in the goat adrenal gland

The distribution patterns of acetylcholine esterase positive nerve fibers in the goat adrenal gland is described. Some positive cells are observed within the capsule. Terminals were identified in both the medulla and the cortex of the gland.

The role of trophoblastic binucleate cells in implantation in the goat: a morphological study

In the goat conceptus individual intra-epithelial trophectodermal binucleate cells first appear 18 days post coitum and their incidence rapidly increases where the trophectoderm is apposed to the caruncular and intercaruncular sites of initial attachment to the uterine epithelium. Special staining techniques reveal that these cells, when mature, contain prominent Golgi bodies and numerous characteristic granules. Our evidence shows that at 19 days post coitum the binucleate cells migrate to the microvillar junction and fuse with individual uterine epithelial cells to form hybrid feto-maternal trinucleate cells. It is proposed that subsequent continued binucleate cell migration and fusion with trinucleate cells produce the syncytial plaques typical of the remainder of pregnancy. It is further suggested that the fusion is important in facilitating the delivery of the characteristic granules to the base of the uterine epithelial layer with subsequent exocytosis of their contents into maternal tissue.

[The synovial organization of the M. fibularis longus in cats, dogs, swine, cattle, sheep and goats]

The synovial structures of the M. fibularis longus were studied by dissection on 23 cat, 28 dog, 20 pig, 17 ox, 15 sheep and 17 goat limbs. Five injections with Technovit into the tarsometatarsal joint were made for each species. The dog had two tendon sheaths while all other species had only one lateral one. The mesotendon approached the tendon from the medial aspect and was fenestrated in the dog (here only in the proximal segment), pig, sheep, and goat, but in the cat and ox the fenestration was inconstant. In the area of the lateral malleolus the lateral tendon sheath narrowed (in the dog only in the proximal segment). The synovial structures on the plantar aspect in the cat, dog, pig, and sheep were formed by a recess of the tarsometatarsal joint; while in the ox and goat they formed a tendon sheath that took its origin from the same joint. The plantar recess surrounded the tendon three quarters of the way in the dog, and in cat, pig, and sheep only half way. Nomenclaturial consequences for the NAV are discussed.

Density of Toruli Tactiles in the goat (Japanese saanen)

Toruli Tactiles (TT) were clearly observed to be stained with methylene blue solution, and the density of distribution of TT on the body surface was measured in the goat. TT in the goat were present on the hairy skin as papilla-like structure of about 200 to 300 microns in plane-diameter. A high density of TT on the body surface occurred in the areas from the lateral portion of the arm to forearm, and from the thigh to leg. On the other hand, areas of low density of TT were present in the facial-cranial region except for the buccal-masseteric area, cranial-breast, perineum (male), axilla, inguen, carpus-metacarpus, and tarsus-metatarsus. TT were rarely observed in the ears, on the nose, around the mouth, perianal parts, palms and soles.

[The ependymal lining of the median eminence in goats]

Ependymal epithelium of eminentia mediana in goats, examined under a light microscope, was found to be formed by beta 2 tanycytes, basal processes reaching the surface of zona externa and bifurcating in zona interna. The thickest is zona interna, consisting of dense fibres of different arrangement. A scanning electrone microscope revealed that the structure of the ependymal surface of eminentia mediana in goats depends on the phase of sexual activity of a given individual. In female and male animals the findings are almost identical (ependymoresorption is prevailing) in the period of quiescence (anoestrus, out of the season, April); an analogical situation was observed in females and males in the period of mating (hyperependymosecretion, October, November). The ependymal surface of eminentia mediana in female animals has also a typical structure in the preparatory pro-estrous stage of sexual cycle, when the results were almost identical with those in a hermaphrodite (secretion and resorption are almost equilibrated). The occurrence of supraependymal cells on the surface of eminentia mediana is scarce. These cells are very similar to nerve cells as to their external morphological structure. The presence of supraependymal fibres on the surface of the bottom of the IIIrd cerebral ventricle can be explained only partly by the finding of supraependymal cells. The investigations revealed that the structure of the surface of the ependymal epithelium of eminentia mediana in goats is markedly differentiated according to the sex; this confirms the participation of tanycytes in the control of the reproductive cycle.

Use of magnetic resonance imaging in the study of goat mammary glands in vivo

A technique is described for the in-vivo determination of mammary gland size and gross composition in goats by using nuclear magnetic resonance imaging (MRI). The volume of test objects determined with MRI had an error of +0.4 +/- 1.6% of the actual volume. In lactating goats the in-vivo MRI estimate of mammary parenchymal volume was significantly greater than, but highly significantly correlated with, the weight of parenchyma determined post mortem (for the whole udder, r = 0.88, P less than 0.001; for individual glands, r = 0.85, P less than 0.001). MRI-determined estimates of the volume of fluid within the mammary gland were within 1.2% of the volume of milk removed from the udders after imaging. The spin-lattice (T1) relaxation time of the whole udder correlated closely with the volume of fluid within the udder. The T1 relaxation time of parenchymal tissue measured in vivo did not differ significantly from that determined immediately after post-mortem excision.

Stereotaxic approach to hypothalamic nuclei of the Shiba goat with radiographic monitoring

Practical method was devised for precise approach to hypothalamic nuclei in the Shiba goat. A stereotaxic instrument and a brain atlas with stereotaxic coordinates were developed. For an accurate placement of probes into specific hypothalamic regions a radiographic method was employed in which radio-opaque material was injected into the lateral ventricle and the ventricular outline was depicted. A sagittal diagram showing the arrangement of hypothalamic nuclei in relation to the brain ventricular system was constructed from the transverse stereotaxic atlas. This diagram was revealed extremely useful in pinpointing the target on the radiographs of lateral view. Precision of this method was evaluated in female Shiba goats (n = 4) by comparing radiographically estimated positions of hypothalamic nuclei with those histologically determined. Despite of cranial variability among individual animals these two parameters matched well each other in all the nuclei examined. Furthermore, chronic cannulae were implanted into different hypothalamic structures of one goat and the accuracy of their placement was confirmed histologically. Thus, it was revealed that the stereotaxy by aid of radiography herein described was accurate enough to apply to various neuroendocrinological studies in the Shiba goat.

The central representation area of the radial nerve in the goat, studied by the axon reaction

The central representation area of the radial nerve has been investigated in the goat, using the axon reaction. The retrograde changes after a two or six weeks survival time have been used to study both its position and architecture. Reconstructions have been made using a computer assisted approach. In the goat the central representation area of the radial nerve is situated in the dorsolateral part of the lateral motoneuronal cell group, extending from caudal C6 to caudal T1. It begins very small in C6, enlarges through C7, reaches its maximal diameter in C8, from where it gradually decreases to end in caudal T1. The contribution of the C6 segment to the central representation area of the radial nerve in the goat is in agreement with findings in some other species but it contrasts with the macroscopic origin of the radial nerve in ruminants. It is suggested that this finding, together with the statistically significant reduction in the number of alpha motoneurons at the C6 level in calves affected with Arthrogryposis Multiplex Congenita (AMC) in the forelimbs, may prove an at least partial involvement of the radial nerve in the pathogenesis of this disease, which is also suggested by clinical symptoms.

Follicle characteristics of non-woolly Indian goats

Skin follicular studies of four non-woolly Indian goat breeds are reported. The number of primary follicles ranged from 2 to 14 mm-2 with an overall mean of 6.40 +/- 0.22. Secondary follicles per mm2 ranged from 1 to 23 with an overall mean of 9.48 +/- 0.55. The secondary/primary follicle ratios (S/P) for Black Bengal, Jamnapari, Barbari and Sirohi goats were 1.57 +/- 0.21, 1.15 +/- 0.16, 1.61 +/- 0.21 and 2.04 +/- 0.21, respectively, with an overall mean of 1.59 +/- 0.99. The corresponding values for the total follicles per mm2 for the four breeds were 16.83 +/- 1.39, 15.86 +/- 1.08, 17.66 +/- 1.41 and 13.19 +/- 1.41 with an overall mean of 15.88 +/- 0.66. Per cent primaries were lowest in Sirohi and highest in Jamnapari goats. Analysis of variance revealed significant differences between breeds for the number of primary follicles and S/P ratio. Sex differences and the interaction between breed x sex were not significant for any of the follicle traits studied. On the basis of follicle characteristics the non-woolly short-haired goats offer a reasonable scope for crossing with fibre goats, and Sirohi goats possibly have better skin quality for leather conversion than other goat breeds studied.