Normal Bulls Research Articles

Effect of Serum Sources and Colostral Whey on Bovine Semen Quality and Spermatozoa Immunoglobulin G Immunofluorescence

Heifer, bull, fetal calf sera, and colostral whey were used to evaluate the influence of protein concentrations on percent progressive motility, head-to-head agglutination, acrosomal integrity, and immunoglobulin G immunofluorescence of bovine spermatozoa using ejaculates from 10 bulls. In the first experiment, 10% (vol/vol) addition of undiluted colostral whey resulted in the highest head-to-head agglutination, acrosomal integrity, and immunoglobulin G immunofluorescence. Ten percent (vol/vol) addition of whey diluted to a protein concentration equivalent to fetal calf serum produced significantly lower agglutination, acrosomal integrity, and immunoglobulin G immunofluorescence. Fetal calf serum was unable to produce agglutination and immunoglobulin G immunofluorescence of bovine spermatozoa. Heifer and bull sera produced similar responses for all seminal measurements. In Experiment 2, unheated whey and heifer serum resulted in higher response for all variables than heat inactivated whey and heifer serum. Whey treatment produced greater spermatozoal motility, agglutination, acrosomal integrity; and immunoglobulin G immunofluorescence than treatment with heifer serum. Spermatozoal immunofluorescence indicated antibodies in normal whey, bull, and heifer serum bound to spermatozoal membranes at the acrosomal region. Colostral whey was an effective source of agglutinin factor. Normal unheated whey and heifer serum did not cause sperm damage or immobilization.

Genetic characterisation of the mithun (Bos frontalis) and studies of spermatogenesis, blood groups and haemoglobins of its hybrids with Bos indicus

The mithun (Bos frontalis) and its hybrids with Bos indicus were studied to provide further cytogenetic information which might throw light on the mechanisms of the male hybrid infertility and facilitate the establishment of a stable crossbreed. It was shown that compared with conventional cattle the mithun has a homozygous, species specific 2/27 centric fusion which reduced the diploid chromosome number from 60 to 58. This provided further proof that Robertson translocation-type rearrangements have been the major source of interspecies karyotype differences in the evolution of the Bovidae. In the mithun there was also significant polymorphism between centromeres of non-homologous chromosomes and there was heteromorphism between several homologous chromosomes which could possibly serve as useful genetic markers for breeding programmes. In F1 hybrids spermatogenesis progressed to a relatively advanced stage, without going so far as to produce spermatozoa. In back crosses to B indicus spermatogenesis progressed further so that spermatozoa could be seen, though not as numerous as in normal bulls. In most hybrids there were haemoglobin bands which corresponded either to Hb A or Hb B of cattle but were much wider. It was shown that these were a combination of Hb Mi derived from the mithun and Hb A or Hb B derived from B indicus. In a few hybrids there were only Hb Mi. In these cases Hb Mi had been present in both parents and proved that the dam was not a pure siri. The possible mechanism of hybrid male infertility is discussed including faults in the epistatic gene effect between chromosomes and changes in the degree of association of centromeric regions in interspecies hybrids. It is suggested that additional cytogenetic examination of blood lymphocytes and especially of testicles would help the understanding of the fertility barriers of hybrid males and would make a breeding programme for a stable crossbreed possible.

Differences in bovine aortic smooth muscle cells cultured from spontaneous atherosclerotic lesions of different severity within the same vessel.

Smooth muscle cells from normal segments, fatty streaks and fibrous plaques spontaneously arisen in the ascending part of the aorta of young normal bulls were grown in culture. Cells from fatty streaks proliferated more rapidly and grew to higher densities than the other cells, but collagen secretion did not differ from controls. In cells from fibrous plaques, however, proliferation rate and final density were the same as for controls, but collagen secretion was significantly increased, both at high and low cell density, compared to the other cells. These cell characteristics were evident in the first as well as in the fifth cell passage. The results support the view that the cell phenotype changes as the atherosclerotic lesions get more advanced, and these changes might be due to senescence and/or selection.

The behaviour and blood profile of bulls which produce dark cutting meat

AbstractThirty British Friesian bulls (12 months old), in groups of 6 or 12, were mixed with unfamiliar animals for 16 h preslaughter. Before and during mixing, blood samples were collected and behaviour was monitored. The ultimate pH (pHu) was measured in the m. Longissimus dorsi (LD) 24 h after slaughter. Thirteen carcasses were dark cutting (DC, pHu≧6) and 17 were normal (pHu<6). DC carcasses came from animals which exhibited over twice the total number of agonistic interactions (P<0.001) and showed more dominant behaviour (P<0.001) than animals producing normal carcasses. There was no difference in the blood profile of DC and normal bulls before mixing. However, DC bulls had higher levels of creatine phosphokinase (P<0.001), free fatty acids (P<0.001) and β‐hydroxybutyrate (P<0.01) in the blood samples collected after mixing. Overall, pHu was correlated with total activity (r=0.71, P<0.001) and dominance scores (r=0.70, P<0.001). The conclusion is that the cause of DC in mixed groups of bulls is primarily behavioural. Muscle glycogen stores are depleted when blood‐borne metabolites are inadequate to fuel the intense or prolonged muscular activity associated with agonistic behaviour.

Normal development following in vitro fertilization in the cow.

A repeatable procedure for fertilization of bovine ova in vitro is described. Oocytes were recovered from ovarian follicles or from oviducts near the time of ovulation following treatment of donors with pregnant mare's serum gonadotropin (PMSG) and prostaglandin F2 alpha (PGF2 alpha). For in vitro capacitation semen was incubated, then high ionic strength treated and subsequently incubated in defined medium prior to insemination of oocytes. In one experiment frozen bull semen was successfully used. In experiments with 4 bulls (B, C, D, F), 34 (43.6%) of 78 ova and 13 (19.7%) of 66 follicular oocytes were fertilized in vitro. In the last series (spermatozoa from Bull F) the fertilization of 22 (62.9%) of 35 tubal ova was achieved. In vitro development proceeded to the 8-cell stage. No fertilization in vitro followed use of one male (Bull E), even though his spermatozoa could penetrate zona-free hamster ova in vitro, and higher than usual bacterial contamination of his semen was implicated as the probable cause. Findings suggested vigorous progressive sperm motility and acrosome integrity to be important features of good sperm samples. In one experiment a 4-cell stage embryo was transferred with the result that the recipient gave birth to a normal bull calf on June 9, 1981. The first calf resulting from in vitro fertilization has been found to be completely normal.

Quantitative macroscopic and histological study of testicular hypoplasia in Bos indicus strain bulls

Forty-six bulls between 17 and 23 months old were used in an investigation of testicular hypoplasia in Bos indicus strain bulls. Testes diagnosed as either unilaterally or bilaterally hypoplastic or normal were obtained at castration and were examined macroscopically and by quantitative histological methods. Estimations of sperm per gram of testis (spg) were made on these 46 bulls and two others. Testis weight was greatest in the 'normal of unilateral' group (106 g). The mean epididymis:testis weight ratio was 0.12 and did not differ significantly between groups. Increased basement membrane thickness, increased vacuolation and giant cells were not features of testicular hypoplasia per se. Seminiferous tubule diameter varied from 118 micrometer in bilaterally hypoplastic testes to 171 micrometer in normal testes. A mean tubule diameter of about 150 micrometer was considered useful for differentiating hypoplastic from normal testes in young post-puberal B indicus crossbred bulls. There was a significant correlation between tubular diameter and spg (r = 0.68, P less than 0.001) suggesting that tubular diameter measurements in histological sections could be used to predict sperm production. Although there was good agreement between clinical diagnosis and spg values, high spg values were found in several small testes which were considered hypoplastic on clinical examination. Examination of both unilaterally and bilaterally hypoplastic testes showed an interesting variation in the ratio of nucleus to cytoplasm in the interstitial cells. This was significantly (p less than 0.05) lower in the testes of normal bulls than in the other clinical groups.

Double reciprocal translocation heterozygosity in a bull.

A double reciprocal translocation has been found in a morphologically normal but infertile bull (Bos taurus), using trypsin-Giemsa banding. The karyotype of the bull can be written as: 60,XY,t(2q-;20q+),t(8q-;27q+). Cytophotometric studies supported the findings in the karyograms and identified the breakpoints in the chromosomes involved. The possible effect of this translocation heterozygosity on male fertility is discussed.

Effect of hemicastration on the level of testicular steroids and growth in bulls and boars

Ten, bull calves of the Norwegian Red breed were hemicastrated at the age of 1 1 2 –3 months . Ten, normal bull calves of similar age served as controls. No significant differences were found in plasma testosterone levels or in weight between the two groups during the ensuing seven-month test period. Eight, male pigs were hemicastrated at 1–2 months of age. Eight, normal male pigs served as controls. Plasma testosterone, androstenone, and body weight were measured fortnightly in all pigs until the age of 6–7 months. Androstenone in adipose tissue was measured from 4–5 months of age. No significant differences were found between normal and hemicastrated animals in any monthly interval. However, when combining the measurement at 5–6 and 6–7 months of age for plasma testosterone and 5α-androstenone and 5α-androstenone in fat, the normal pigs had significantly higher values than the hemicastrates (p<0.05). The weight of the single testis from the hemicastrated pigs at slaughter nearly equalled the combined weight of both testes from the controls. Thus, hemicastration did not appear to have any significant effect on the level of testicular steroids in plasma in bulls or growth rate in bulls and boars, but did have a slight effect on testicular steroids in plasma in pigs at 5–7 months of age.

Disappearance of Inhibin‐like Activity in Bull Seminal Plasma Following Castration

Ejaculates from normal and castrated bulls were evaluated for the presence of inhibin‐like activity. Inhibin activity found in the seminal plasma of normal bulls became undetectable after castration. Crude protein concentrates prepared from the ejaculates of castrated bulls failed to produce inhibition of FSH secretion as measured by in vivo and in vitro tests: a) hCG‐induced uterine weight test in mice and b) LH‐RH‐induced FSH secretion in 34‐day‐old male mouse pituitary. The concentrates also lacked the ability to inhibit the binding of iodine‐125 (125I)‐labeled inhibin fraction from normal bull seminal plasma to ovine pituitary membranes. Chromatographic and electrophoretic analyses of the ejaculate from castrated bulls revealed the absence of the band corresponding to inhibin of normal bull seminal plasma.

Effect of scrotal streptothricosis on spermatogenesis in the bull.

Cutaneous streptothricosis was observed in 171 (13.42 per cent) out of 1274 animals examined over a period of 12 months. Eighty-six (8.30 per cent) of the 1036 bulls examined had cutaneous and scrotal streptothricosis and 85 (35.71 per cent) of the 238 cows had cutaneous streptothricosis of varying degrees. More cattle were affected during the rainy and pre-dry seasons when the condition was more extensive and severe. Histologically, moderate testicular degeneration was observed in 15 (13.6 per cent) of 110 streptothricosis-free bulls and 14 (16.3 per cent) of the 86 bulls with scrotal streptothricosis. No correlation was found between scrotal streptothricosis and testicular degeneration and, or inflammation. Average percentage spermatogenesis was 89.7 per cent for normal bulls, 91.2 per cent and 89.5 per cent for bulls with mild and moderate scrotal streptothricosis respectively and 88.0 per cent for bulls with severe scrotal streptothricosis. Two chronic cases had an average percentage spermatogenesis of 89.0 per cent. There was no correlation between the degree and extent of scrotal streptothricosis and spermatogenesis. The slight increase in the thickness of the scrotum was not observed to affect the normal course of spermatogenesis.

The Dag defect of the tail of the bull sperm. Studies on the inheritance and pathogenesis

During the period 1963–1979, 15 spontaneous cases of the sterilizing Dag defect of the sperm tail in Danish Jersey bulls have been examined. The pedigree of these bulls could be traced back through both paternal and maternal lines to a common ancestor bull born in 1934. The probable heredity of the defect was tested in a sire-daughter breeding experiment. Six bulls out of 38 sons born produced semen typical of the Dag defect thus confirming that the defect is due to the presence of an autosomal recessive factor. Systematic examination of the epididymal contents from 17 bulls revealed that the defect consistently developed in the distal part of the epididymal caput. Neither biophysical and biochemical qualities of the epididymal contents nor the histological appearance of the duct epithelium differed from the findings in normal bulls.

Studies on porphyrin biosynthesis and enzymes involved in bovine congenital erythropoietic porphyria.

1. Porphyrin biosynthesis and the enzymes succinyl-CoA synthetase (EC 6.2.1.5), δ-aminolaevulinate synthase (EC 2.3.1.37), δ-aminolaevulinate dehydratase (EC 4.2.1.24) and porphobilinogenase enzyme complex at 37°C and 45°C were studied in blood, bone marrow, spleen, liver and kidney of normal bulls and a bull with congenital erythropoietic porphyria (CEP). 2. Biosynthesis by erythrocytes and spleen was low and slightly lower in CEP than in the normal animals. In liver and kidney biosynthesis was somewhat higher and still lower in CEP than in normal animals. In bone marrow it was high and considerably higher in CEP than in normal animals. In all tissues biosynthesis was higher from porphobilinogen than from δ-aminolaevulinic acid. 3. The porphyrin biosynthesis pattern was 40% uroporphyrin, 15% heptacarboxylic porphyrin, 25% coproporphyrin and 20% suburoporphyrin in the normal animals, but in CEP it was 50% uroporphyrin I, 20–30% uroporphyrin III, 10–12% heptacarboxylic porphyrin and 10–20% suburoporphyrin. 4. In CEP gall-bladder bile contained 100 μmol of coproporphyrin/l and the fresh bladder urine 9 μmol/l, which on standing increased to 21 μmol/l, pointing to excretion of most porphyrin as porphyrinogen in the urine. The blood plasma contained only traces of porphyrin. 5. Enzyme determinations showed threefold increased succinyl-CoA synthase in CEP bone marrow as compared with normal animals, many-fold increase of aminolaevulinate synthase, normal aminolaevulinate dehydratase, sevenfold increase of porphobilinogenase activity on incubation at 45°C and threefold increase at 37°C. In blood, aminolaevulinate synthase and aminolaevulinate dehydratase were increased in CEP, whereas porphobilinogenase at 45 °C was reduced. In liver, aminolaevulinate synthase was normal and porphobilinogenase decreased. 6. Our results show that in this animal with CEP there was an increased porphobilinogen deaminase and a significant enhancement of aminolaevulinate synthase concomitant with a diminished activity of uroporphyrinogen III cosynthase.

Impotence in the bull: (1) Abnormal venous drainage of the corpus cavernosum penis.

Six young bulls (two Friesian, two Charolais, one polled Devon and one North Devon) that had never served successfully, showed good libido but lacked penile erection. In five of these bulls, the short flaccid organ was not protruded during attempted service. Radiography of the cavernous bodies and veins of the penis in the living animal demonstrated major venous drainage of the corpus cavernosum penis (ccp) by the dorsal venous system in all cases. This was not seen in normal bulls. Radiography and anatomical preparations of post mortem specimens showed that the ccp was drained by the dorsal venous system throughout the length of the organ. Proximally, the cavernous spaces of the ccp anastomosed with those of the corpus spongiosum penis (csp) and were drained by numerous small veins. Distally, a system of larger veins, not seen in normal bulls, drained into left and right sides of the dorsal venous system. No microscopical abnormalities of spermatozoa or of testes were found, but there was a marked lack of spermatozoa in the caudae epididymides. The evidence suggests that abnormal venous drainage of the ccp may have been the immediate cause of impotence in these bulls.

Tubule length and Leydig cell volume in the normal bull testis

Data are presented on the size, Leydig cell content and seminiferous tubule dimensions of the normal bull testis. A method of estimating total tubule length, requiring only the measurement of testis volume and the number of tubule cross-sections in a unit area is described, and its applicability to the bull established. The average bull testis contains about 5.2 km of tubules.

Testosterone secretion in cryptorchid and intact bulls injected with gonadotropin-releasing hormone and luteinizing hormone.

The effect of artificial cryptorchidism on serum concentrations of LH, FSH, and testosterone in mature bulls has been examined. When compared to normal intact bulls, cryptorchid bulls had elevated (P 0.10) in cryptorchid bulls...

Sterility in hybrid cattle. I. Distribution of constitutive heterochromatin and nucleolus organizer regions in somatic and meiotic chromosomes.

The distribution of constitutive heterochromatin and nucleolus organizer regions (NOR's) in somatic as well as in meiotic chromosomes of Bos taurus, Bos banteng, Bison bison, and their hybrids are analyzed. C-bands are present in the centromeric regions of every autosome. The X chromosome does not show a distinct C-band in the centromeric region, whereas the Y chromosome contains an appreciable amount of C-band material. In somatic metaphases, NOR's are present on the telomeric ends of five pairs of autosomes. During pachytene, five autosomal bivalents contain NOR's on their terminal ends. Meiotic preparations made from sterile bulls did not contain stages beyond the degenerating pachytene, which are C-banding, more frequently showed clustering of heterochromatin than did the pachytene stage in normal bulls.

Meiosis and spermatogenesis in bulls heterozygous for a presumptive 1/29 Robertsonian translocation.

Bulls heterozygous for the 1/29 Robertsonian translocation showed normal mating behaviour, semen quality and spermatogenesis. The karyotypes of 90 offspring of one heterozygous bull were consistent with a normal 1:1 segregation of the translocation. There was no difference in overall chiasma frequency at diakinesis between heterozygous and normal bulls, and while a trivalent was noted at diakinesis the chiasma position within the No. 1 arm of the trivalent did not appear to be altered when compared with that found in the normal No. 1 bivalent. An increased frequency of aneuploid secondary spermatocytes at the second meiotic division (M II) was found in the heterozygous bulls, the rate of non-disjuction based on the proportion of hypermodal cells being raised from 2.8% in the normal to 6.4% in the heterozygous animals.

Staining technique for definite identification of individual cattle chromosomes in routine analysis.

The purpose of the present communication is to draw attention to the great applicability of a recently introduced R-banding technique for definite identification of cattle chromosomes in routine analysis. Banding patterns as well as densitometric measurements of normal bull chromosomes and the so-called 1/29 translocation are demonstrated.

A quantitative histological study of changes in the bovine testis and epididymis associated with age

Quantitative histological studies were performed on the testis and epididymis of 80 normal bulls from beef herds in tropical Australia. Four age groups, ranging from nine months to over 10 years were established. Volumetric proportions of parenchymal and collagenous tissues, and tubular or duct surface to tissue volume ratios were determined at the dorsal, middle and ventral testicular regions and at the head, body and tail of the epididymis for each group. Detailed volumetric analyses of the relative volumes of particular parenchymal and stromal elements were made a the middle testicular region. Lymphoid and plasma cell populations were compared in all regions, including the efferent ducts. Differences in the distribution of testicular parenchyma and collagen were found; the dorsal region had more parenchyma and less collagen than the middle and ventral areas. Progressive intertubular fibrosis attributed to age was quantified; it was most marked ventrally. Reductions in the relative volumes of germinal cells, Sertoli cells, tubular cytoplasm and parenchyma, and in tubular surface to testis volume ratios with advancing age, indicated a decrease in the capacity per unit volume of testis to produce sperm. Increased immunocyte populations in the efferent duct region in young bulls were attributed to initial antigenic exposure. Increased antigenic exposure, in association with senile degenerative changes of the genitalia, might have caused the increased immunocyte populations seen in very old bulls.

Sperm Production of Holstein Bulls Determined from Testicular Spermatid Reserves, after Cannulation of Rete Testis or Vas Deferens, and by Daily Ejaculation

The relationship between sperm production and sperm output was reexamined with data from 50 bulls. Sperm output in semen collected daily by artificial vagina averaged 6.46×109/day (47 bulls). The volume (ml/day), cell concentration (106ml), and sperm output (109/day) from a cannulated rete testis (21 measurements) averaged 41.3, 70, and 2.83 while corresponding values for cauda epididymal semen obtained via a vas deferens cannula (20) averaged .8, 5387, and 3.93. Comparisons within bulls for pairs of measurements revealed no significant difference in the number of sperm recovered from the rete testis, from the cauda epididymidis, or representing one-half of those ejaculated daily before surgery. These values were similar to estimates of sperm production calculated with a new time divisor (5.32 days) to convert testicular spermatid reserves to sperm production. Each method used can give valid estimates of daily sperm production. In normal bulls few if any sperm are resorbed in the epididymis.Sperm transport through the epididymis was not retarded by ligation of the efferent ducts. The time required for sperm to traverse the epididymis of a bull ejaculated daily averaged 8 days but ranged from 4 to 15 days.