N. R. Kendall

The interobserver reliability and validity of volume calculation from three‐dimensional ultrasound datasets in the in vitro setting

The primary aim of this validation study was to determine the interobserver reliability and validity of measurements of phantom objects of known volume using conventional and rotational techniques of volume calculation according to measurement technique.

The reliability of virtual organ computer‐aided analysis (VOCAL) for the semiquantification of ovarian, endometrial and subendometrial perfusion

Three‐dimensional power Doppler angiography (3D‐PDA) has been largely used for the subjective assessment of vascular patterns but semiquantification of the power Doppler signal is now possible. We examined the intraobserver and interobserver reliability of the semiquantification of ovarian, endometrial and subendometrial blood flow using 3D‐PDA, virtual organ computer‐aided analysis (VOCAL™) and shell‐imaging.

The interobserver reliability of three-dimensional power Doppler data acquisition within the female pelvis

To examine the interobserver reliability of three‐dimensional (3D) power Doppler data acquisition from the uterus and ovary.

The effect of a zinc, cobalt and selenium soluble glass bolus on trace element status and semen quality of ram lambs.

Supplemental zinc and selenium were administered to ram lambs grazed on pastures that were not considered to be deficient in either element. The breeding season and polygamy of the ram mean that his requirements for semen production will be relatively large over a short breeding season and this may induce a localised deficiency of zinc and/or selenium, thus resulting in a decrease in semen quality and production.Thirty-three 8-month-old ram lambs were kept at grass and fed a supplement of barley and peas, with ad libitum access to grass silage when grazing became restricted. On day 0, the rams were allocated to two groups by restricted randomisation of live weight. One group each had a zinc, cobalt and selenium soluble glass bolus (Zincosel(R), Telsol) administered with the other group not receiving a bolus to act as a control. Blood samples were taken by jugular venipuncture at day 0 (prior to bolus administration) and at days 23, 44, 65 and 86. Blood samples were analysed for zinc status (plasma zinc concentration) and selenium status (erythrocyte glutathione peroxidase activity). Semen was collected once a week between days 44 and 86, by diversion during a natural mount. Semen quality was assessed by ejaculate volume, spermatocrit, sperm concentration, abnormal morphology, motility, percentage live (negrosin-eosin stain), membrane integrity (hypo-osmotic swelling test (HOS)) and seminal fluid glutathione peroxidase activity and zinc concentration. The bolused lambs had a significantly increased erythrocyte glutathione peroxidase activity (P<0.01) on all samplings after bolusing and had significant increases in motility, proportion of live sperm and proportion of intact membranes indicated by the HOS. The bolused ram lambs had an increased selenium status and apparent improvement in semen membrane quality.

Defining endometrial growth during the menstrual cycle with three‐dimensional ultrasound

Objective  To define the changes in endometrial morphometry that occur during the normal menstrual cycle and to examine the discriminatory power of volumetric analysis over conventional two‐dimensional measurements in quantifying the effect of compounding factors on endometrial growth.

Role of the rumen in copper and thiomolybdate absorption.

The rumen is the site of significant interactions between Cu, S and Mo. It also shows reactions between Cu, S and Fe. The interaction between Mo and S results in the formation of thiomolybdates, which in the absence of adequate quantities of rumen Cu are absorbed into the animal and bind to Cu in biological compounds. This is the cause of thiomolybdate toxicity, often misleadingly called Cu deficiency. The effects of thiomolybdates being absorbed into the animal are considered, especially how thiomolybdates bind to Cu-containing compounds such as enzymes, decreasing their activity without removing the active Cu component. The sources of Cu, Mo, Fe and S are examined, including the impacts of water and soil on the animals intake. Within the present review we have been able to provide evidence that: all classes of thiomolybdates are formed in the rumen; in the absence of available Cu all thiomolybdates can be absorbed into the animal rapidly though the rumen wall or via the small intestine; thiomolybdates bind to Cu in biological compounds and are able to cause problems; effects of thiomolybdate are reversible in vivo and in vitro on cessation of thiomolybdate challenge; the tetra-thiomolybdate form is the most potent Cu binder with decreased potency with decreasing S in the compound. Fe will exacerbate a thiomolybdate problem but will not directly cause it.

Incidence and treatment of inadequate postovulatory progesterone concentrations in repeat breeder cows

The incidence of low day 5 milk progesterone in dairy cows has been investigated and the efficacy of treating the problem assessed. The incidence of inadequate milk progesterone (empirically defined as <3ng/mL) in repeat breeder cows was 34% compared with 11.4% in first insemination cows. Treatment with an intravaginal progesterone device for 7 days starting from day 5 or 6 did not improve pregnancy rate. Treatment with 1500 iu human chorionic gonadotrophin (hCG) on day 5 gave an increase in pregnancy rate that was dependent on initial progesterone concentration and significant (P<0.05) in multiparous but not primiparous cows. While the incidence of inadequate day 5 progesterone was high in repeat breeder cows, it was responsive to hCG treatment, although only in multiparous and not primiparous animals.

Energy metabolites in pre- and postpartum dairy cattle as predictors of reproductive disorders

This study aimed to determine values for selected energy metabolites (non-esterified fatty acid [NEFA], β-hydroxybutyrate [BHB], urea or urea:BHB ratio), together with a body condition score, associated with an increased risk of cows developing a reproductive disorder and to investigate temporal relationships between predictors and reproductive outcome. A cohort of 98 cows on one farm was monitored weekly from four weeks before to 10 weeks after calving; 89 cows provided sufficient data to calculate commencement of luteal activity (C-LA). Cows with high NEFA × urea (Nu; product of NEFA and urea) values one and three weeks after calving were twice as likely to develop cystic ovarian disease (risk ratio 2). Cows that developed endometritis had high NEFA values one (P=0.02) or four weeks (P=0.04) before calving, or low urea:BHB ratios two weeks before calving, at calving or three weeks after calving (P=0.024, P=0.031 and P=0.001, respectively). Cows that had delayed C-LA had high NEFA values one week after calving (P=0.05) or low urea:BHB ratios three or four weeks after calving (P=0.004 and P=0.003, respectively).

Temporal relationships between FSH receptor, type 1 insulin-like growth factor receptor, and aromatase expression during FSH-induced differentiation of bovine granulosa cells maintained in serum-free culture.

A serum-free culture system has been developed in ruminants that allows gonadotrophin-responsive induction of oestradiol (E2) production by non-differentiated granulosa cells (GC) from small antral follicles. Critical determinants are dose of FSH and insulin-like growth factor (IGF), and the plating density of the GC. Over the first 16 h of culture when cells remained as a dispersed monolayer, expression declined in FSH receptors (FSHr) (P <0.001), IGF type 1 receptor (IGF-1r) (P <0.08) and p450 arom (CYP19, P <0.001). Characteristic GC clusters formed from 16 h and further enlarged between 24 and 48 h, accompanied by marked increases in FSHr (P <0.01), IGF-1r (P <0.05), and p450 arom (P <0.01) expression, and preceded induction and subsequent peak E2 production, at 96 and 144 h, respectively (P <0.01). In conclusion, isolation and dispersion of GC appears to induce reversion to an immature state resulting in loss of receptor expression. Re-establishment of cell-cell communications in the presence of FSH and IGF results in receptor up-regulation and induction of cellular differentiation.

The effect of monosaccharide sugars and pyruvate on the differentiation and metabolism of sheep granulosa cells in vitro

The objective of this study was to investigate the effect of three monosaccharides or pyruvate on the ability of gonadotrophins to induce cellular proliferation and differentiation of cultured sheep granulosa cells. Lactate production and levels of mRNA expression for the glucose transporters SLC2A1, SLC2A4, SLC2A5 and SLC2A8 were also determined. No energy source in the culture media reduced cell number (50%) and oestradiol (E(2)) production. Dose and type of monosaccharide had a highly significant (P<0.001) effect on FSH-induced differentiation of the granulosa cells, and there was a highly significant interaction (P<0.001). Glucose supported higher levels of E(2) production than fructose, which was in turn higher than galactose (P<0.001). In contrast, pyruvate at low doses supported similar levels of E(2) production as glucose, but higher doses were markedly inhibitory to E(2) production (P<0.001). Cells responded positively to insulin (P<0.001) in the presence of all three monosaccharides. Glucose and the high doses of fructose resulted in the accumulation of lactate (P<0.001), but pyruvate, galactose and the low dose of fructose resulted in low lactate production. SLC2A5 expression was not detected and SLC2A8 expression was not affected, but SLC2A1 and SLC2A4 expression was depressed (P<0.05) by culture in the presence of fructose and glucose. These data show that glucose, metabolised under anoxic conditions to lactate, is the preferred energy substrate to support the gonadotrophin-induced differentiation of ovine granulosa cells in vitro, and that fructose and pyruvate, but not galactose, are alternative energy substrates despite marked differences in the way these substrates are metabolised.