Captive breeding of the white rhinoceros, Ceratotherium simum, and the Cape buffalo, Syncerus caffer.

Breeding records of 40 white rhinoceros and 155 Cape buffalo were analysed. Three rhinoceros cows bred in captivity, themselves conceived for the first time at 84, 87 and 95 months of age, respectively. Rhinoceros cows breed throughout the year.

A critical look at semen analysis.

In this article, human semen analysis is examined critically and some of the difficulties it presents in terms of interpretation are highlighted. The problem of defining fertility is raised and a brief comparison is made between farm animals and humans. The purpose of analysis in each differs markedly, yet conventional tests on human semen are derived from semen analysis in animals.

The antenna cleaner gland in Messor rufitarsis (hymenoptera, formicidae).

TEM and SEM analysis of the tibio-tarsal antennal cleaner in Messor rufitarsis reveals a pore region on the surface of the basitarsus. These pores are originating from a cluster of highly prismatic epidermal cells that fill the anterior hemolymph space of the leg almost completely. Within the cytoplasma of the cells, basal labyrinth, nucleus/rough endoplasmic reticulum, 'secondary lysosomes', a lot of smooth endoplasmic reticulum and distal microvilli regions can be distinguished indicating that the cells are 'class I' gland cells.

Changes in androgen concentrations during puberty and their relation to behaviour in male Saccostomus campestris (Gray 1844), an African rodent.

Sexual development in male Saccostomus campestris, the pouched mouse, was studied in terms of morphological development and changes in concentrations of plasma testosterone and androstenedione. The interaction of adult females and males following the introduction of a male was observed at all stages of the oestrous cycle. The histology of the reproductive organs is similar to that of other rodents.

Cytogenetic studies of 1-29 translocation carrying cows and their embryos.

An examination has been made of embryos from infertile 1-29 translocation carrying heifers. Cytogenetic measurements of C-banded chromosomes from these cattle, together with those from fertile 1-29 cows, have been made and compared with those from normal karyotypes. There are relative differences between normal animals and translocation carriers in the ratios of total to C-banded material throughout the karyotypes: their possible effects on mitosis and meiosis are discussed.

Motility of bovine spermatozoa studied by laser light scattering.

Laser light scattering has been employed to determine the swimming speed distribution and the fraction of motile cells in samples of bovine spermatozoa. As predicted from theory, average trajectory velocities determined by laser light scattering were approximately four times the average translational speed estimated using light microscopy. The proportion of motile spermatozoa decreased with time at the same rate when samples were prepared in either HEPES or phosphate buffers.

The effects of acidic epididymal glycoprotein (AEG) and some other proteins on the motility of rat epididymal spermatozoa.

Acidic epididymal glycoprotein (AEG) had a slight stimulatory effect on the motility of spermatozoa showing low initial motility which had been removed by micropuncture from the caput and corpus epididymidis of rats. However, similar effects were seen when bovine serum albumin (BSA) or purified gammaglobulin against AEG was used instead of AEG. Furthermore, BSA, normal rabbit serum and serum from a rabbit immunized against AEG reduced the motility of spermatozoa which showed high initial motility after removal from the caput, while AEG had no effect.

Bovine serum albumin, sperm motility, and the "dilution effect'.

Epididymal spermatozoa from rabbit and ram were washed either once or twice using an efficient washing procedure and were then diluted in various media to a final concentration of approximately 1.4 x 10(7) cells/ml and incubated at 30 degrees C for up to 12 hours. Bovine serum albumin (BSA), either untreated or defatted, was found to be better than polyvinylpyrrolidone, ovalbumin, or alpha-lactalbumin, both at stimulating and maintaining motility levels and at reducing the tendency of the washed spermatozoa to stick to glass.

Effects of carnitine and some related compounds on the motility of rat spermatozoa from the caput epididymidis.

Spermatozoa were collected from the rat caput epididymidis by micropuncture and their motility assessed after dilution in physiological saline containing carnitine or related compounds. L(+)-Carnitine caused, 2 min after dilution, a transient stimulation of the motility of spermatozoa with low initial motility. No stimulatory effects were seen on spermatozoa which had high initial motility.

Changes in luminal plasma and disappearance of spermatozoa from the ligated cauda epididymidis of the androgen-deficient rabbit.

By 3 weeks after castration the majority of spermatozoa in the ligated cauda epididymidis were dead and decapitated and there was a 46% reduction in the total number of spermatozoa. By 5 weeks after castration > 99% of spermatozoa had disappeared. Electrophoresis of cauda epididymal plasma (CEP) on polyacrylamide gels revealed that after castration the protein composition of CEP changed from a pattern specific to the epididymis to one similar to blood serum.

Effect of exogenous gonadotrophin (PMSG) on the antral follicle population in the sheep.

Follicles were obtained from the ovaries of four groups of 15 ewes. Ewes in the control group were ovariectomized on the 12th day of the oestrous cycle. The other ewes were all given PMSG on the 12th day of the cycle; some were ovariectomized 24 or 40 h later, the others were given prostaglandin followed by hCG and were ovariectomized 6 or 12 h after the hCG injection.

The construction of a membrane slide support for the observation of living cells.

The construction of a slide for examining living cells under the microscope under controlled conditions is described.

Regeneration of atretic sheep ovarian follicles in vitro.

Large (4--6 mm diam.) and small (2--3 mm) atretic follicles were removed from sheep ovaries during the luteal phase of the cycle and maintained in organ culture without hormonal supplementation for up to 5 days. The structure, cell dynamics and steroid-producing capacity of the follicles were compared with those of non-atretic follicles of similar size.

Measurement of the motility of rat spermatozoa collected by micropuncture from the testis and from different regions along the epididymis.

Spermatozoa from the testis and various regions along the epididymis of the rat were collected by micropuncture and their motility after dilution was estimated over a 15-min period by using a Quantimet image analyser. The motility of sermatozoa from the rete testis and seminiferous tubules was too low to be measured. The estimate of motility of spermatozoa from the proximal caput epididymidis was much lower than that of spermatozoa from the other regions.

The estimation of sperm motility in semen, on a membrane slide, by measuring the area change frequency with an image analysing computer.

A simple slide is described in which the base is a permeable membrane so that a suspension of spermatozoa (or other cells) may be examined under controlled conditions with a microscope. An objective method of assessing the motility of spermatozoa in undiluted or diluted semen from a wide variety of species including cattle, horse, pig, rabbit, rat and sheep is described. It is shown to be well correlated with other methods of assessing motility and also with the non-return rate obtained with frozen cattle semen.

The maintenance of motility and the surface properties of epididymal spermatozoa from bull, rabbit and ram in homologous seminal and epididymal plasma.

Epididymal spermatozoa from bull, rabbit and ram were incubated in homologous epididymal plasma or seminal plasma in a buffered saline-based medium with or without serum albumin. The spermatozoa were either diluted directly into the medium or were washed first. No effect of washing was observed on the subsequent reaction of the cells to the different media.

Macroscopic identification and steroidogenic function of atretic follicles in sheep.

The degree of translucency, vascularization of the follicle wall and the integrity of the membrana granulosa, as seen under a stereoscopic microscope, were used to distinguish between non-atretic and atretic isolated follicles. Subsequent histological evaluation showed that both non-atretic and severely atretic follicles could be correctly identified with over 95% accuracy. The concentrations of steroids were measured in both follicular tissue and fluid.

Effect of ionic strength, serum albumin and other macromolecules on the maintenance of motility and the surface of mammalian spermatozoa in a simple medium.

The seminal plasma in sperm suspensions from boar, bull, rabbit, ram and stallion was replaced with simple defined media as completely as possible by a combination of centrifugation through Ficoll and dilution. After this process, motility declined and the cells showed a tendency to agglutinate and/or stick to glass. Varying the ionic strength of the medium had little effect upon these parameters but sperm motility was preserved better in the presence of serum albumin.

Artificial insemination with spermatozoa in formaldehyde.

The ability of formaldehyde to preserve the integrity of the membranes of spermatozoa, as indicated by eosin staining (Dott & Foster, 1975), prompted an investigation to discover what other properties of spermatozoa were preserved by low concentrations of formaldehyde in vitro. In a series of experiments on bull, ram and boar spermatozoa it has been shown that spermatozoa rendered immotile by formaldehyde recovered their motility when the formaldehyde was removed by washing up to 12 hr afterwards (H.M.

Methods of measuring swimming speed of spermatozoa.

Three basic approaches for determining the mean swimming speed of a suspension of microorganisms were compared, using bull and ram spermatozoa. Number fluctuation counting was performed automatically on a Quantimet 720 image analysing computer, the mean speed being obtained using 'probability after' statistics. The other two approaches were photomicrographic: number flux counting was performed on single photomicrographs; on the same photomicrographs, the mean speed was estimated from measurement of 'whole' and 'half' track lengths.

Preservation of differential staining of spermatozoa by formol citrate.

Semen from boar, bull, ram, rabbit, reindeer and stallion was diluted in formol citrate or formol saline and stained with eosinnigrosin. The proportion of eosinophilic spermatozoa did not differ from that in fresh semen after storage for 48 hr in the formol diluent at temperatures ranging from 4 degrees C to 40 degrees C. Some samples were kept for periods up to 3 weeks with very little increase in the proportion of eosinophilic spermatozoa.