Self-fertilization, long-distance flash invasion and biogeography shape the population structure of Pseudosuccinea columella at the worldwide scale.

Population genetic studies are efficient for inferring the invasion history based on a comparison of native and invasive populations, especially when conducted at species scale. An expected outcome in invasive populations is variability loss, and this is especially true in self-fertilizing species. We here focus on the self-fertilizing Pseudosuccinea columella, an invasive hermaphroditic freshwater snail that has greatly expanded its geographic distribution and that acts as intermediate host of Fasciola hepatica, the causative agent of human and veterinary fasciolosis. We evaluated the distribution of genetic diversity at the largest geographic scale analysed to date in this species by surveying 80 populations collected during 16 years from 14 countries, using eight nuclear microsatellites and two mitochondrial genes. As expected, populations from North America, the putative origin area, were strongly structured by selfing and history and harboured much more genetic variability than invasive populations. We found high selfing rates (when it was possible to infer it), none-to-low genetic variability and strong population structure in most invasive populations. Strikingly, we found a unique genotype/haplotype in populations from eight invaded regions sampled all over the world. Moreover, snail populations resistant to infection by the parasite are genetically distinct from susceptible populations. Our results are compatible with repeated introductions in South America and flash worldwide invasion by this unique genotype/haplotype. Our study illustrates the population genetic consequences of biological invasion in a highly selfing species at very large geographic scale. We discuss how such a large-scale flash invasion may affect the spread of fasciolosis.

A model for preservation of thymocyte-depleted thymus.

DiGeorge syndrome is a disorder caused by a microdeletion on the long arm of chromosome 22. Approximately 1% of patients diagnosed with DiGeorge syndrome may have an absence of a functional thymus, which characterizes the complete form of the syndrome. These patients require urgent treatment to reconstitute T cell immunity. Thymus transplantation is a promising investigational procedure for reconstitution of thymic function in infants with congenital athymia. Here, we demonstrate a possible optimization of the preparation of thymus slices for transplantation through prior depletion of thymocytes and leukocyte cell lineages followed by cryopreservation with cryoprotective media (5% dextran FP 40, 5% Me2SO, and 5% FBS) while preserving tissue architecture. Thymus fragments were stored in liquid nitrogen at -196°C for 30 days or one year. The tissue architecture of the fragments was preserved, including the distinction between medullary thymic epithelial cells (TECs), cortical TECs, and Hassall bodies. Moreover, depleted thymus fragments cryopreserved for one year were recolonized by intrathymic injections of 3×106 thymocytes per mL, demonstrating the capability of these fragments to support T cell development. Thus, this technique opens up the possibility of freezing and storing large volumes of thymus tissue for immediate transplantation into patients with DiGeorge syndrome or atypical (Omenn-like) phenotype.

Radiographic and laser fluorescence methods have no benefits for detecting caries in primary teeth.

Clinical guidelines advise that dentists take radiographs in children to detect caries lesions missed by visual inspection; however, due to the current low caries prevalence in most countries, we hypothesized that the adjunct methods of caries detection would not significantly improve the detection of primary molar lesions in comparison to visual inspection alone. We evaluated the performance of visual inspection, alone or in combination with radiographic and laser fluorescence pen (LFpen) methods, in detecting occlusal and approximal caries lesions in primary molars. Two examiners evaluated children who had sought dental treatment with these diagnostic strategies. The reference standard involved the temporary separation of approximal and operative interventions for occlusal surfaces. The sensitivity, specificity, accuracy and utility of diagnostic strategies were calculated. Simultaneous combined strategies increased sensitivities but decreased specificities. Furthermore, no differences were observed in accuracy and utility, parameters more influenced by caries prevalence. In conclusion, adjunct radiographic and laser fluorescence methods offer no benefits to the detection of caries in primary teeth in comparison to visual inspection alone; hence, present clinical guidelines should be re-evaluated.

Diarrheic syndrome as a clinical sign of intestinal infiltration in progressive B-cell chronic lymphocytic leukemia.

Gastrointestinal involvement is a rare event in patients with B-cell chronic lymphocytic leukemia (B-CLL) and is usually associated to lymphomatous transformation. However, in autopsy studies the reported incidence of microscopic infiltration can reach up to 50% of cases. Seven B-CLL patients in advanced stage/progressive disease were evaluated by colonoscopy because of continuous diarrhea. Five out of seven patients (71%) presented histological evidence of colonic infiltration. Persistent diarrhea in patients with progressive/advanced B-CLL can be a clinical sign of intestinal infiltration and justifies endoscopic examinations.

Beyond scoring systems: usefulness of morphometry considering demographic variables, to evaluate neck and overall obesity in Andalusian horses.

Morphometry has proven to be a useful tool, both for the clinician and horse owners, for evaluating the body condition in equids due to its objectivity, easiness and capacity for detection of important metabolic disturbances. However, limited information is available on the use of morphometric ratios to characterize regional and overall adiposity and much less about their application in different genders, ages and horses with different levels of obesity. The objectives were to evaluate body and neck absolute measurements and ratios; factors affecting them such as the influence of gender, age, appearance of the neck crest and overall body condition and; relationships among these measurements. A total of 154 Andalusian horses classified according to their gender, age, body score status and cresty neck condition were evaluated in this cross-sectional study. Two evaluators assigned a body condition score (BCS, 1 to 9) and a cresty neck score (CNS, 0 to 5) to each horse. Horses were divided into males and females; young (2 to 5 years) and adults (6 to 15 years); obese (BCS⩾7) and non-obese (BCS<7); cresty neck (CNS⩾3) and non-cresty neck horses (CNS<3). Morphometric measurements (cm) included were: height at the withers (HW); body length (BL), girth (GC) and waist (WC) circumferences; neck length (NL); three neck circumferences (NCs), over the first (NC25%), the second (NC50%) and the third part (NC75%) of the NL and neck crest height (NCH). These measurements were also used to calculate the following ratios: GC : HW, WC : HW, GC : BL, WC : BL, NC25% : HW, NC50% : HW, NC75% : HW, NC25% : BL, NC50% : BL, NC75% : BL, NC25% : NL, NC50% : NL, NC75% : NL, NC25% : NCH, NC50% : NCH and NC75% : NCH. The results showed that most of the absolute measurements and ratios were greater than those described in other light breeds. In addition, most neck ratios were higher (P<0.050) in males than in females, however, all body ratios were greater (P<0.001) in females. Among the absolute measurements, WC in obese horses and NC25% and NC75% in cresty neck horses highlighted as higher. Either GC : HW or WC : HW and NC75% : BL were alternative surrogates for the appraisal of overall and regional adiposity in Andalusians. Several interactions were observed between the gender and adiposity scoring systems affecting the morphometric evaluation. This study establishes absolute morphometric measurements and ratios in Andalusian horses. It also highlights the variability of morphometric values and how the outcome of these can be influenced by demographic variables and the breed analyzed. Further studies are necessary to set morphometric reference values in other breeds.

A model for preservation of thymocyte-depleted thymus

DiGeorge syndrome is a disorder caused by a microdeletion on the long arm of chromosome 22. Approximately 1% of patients diagnosed with DiGeorge syndrome may have an absence of a functional thymus, which characterizes the complete form of the syndrome. These patients require urgent treatment to reconstitute T cell immunity. Thymus transplantation is a promising investigational procedure for reconstitution of thymic function in infants with congenital athymia. Here, we demonstrate a possible optimization of the preparation of thymus slices for transplantation through prior depletion of thymocytes and leukocyte cell lineages followed by cryopreservation with cryoprotective media (5% dextran FP 40, 5% Me2SO, and 5% FBS) while preserving tissue architecture. Thymus fragments were stored in liquid nitrogen at -196°C for 30 days or one year. The tissue architecture of the fragments was preserved, including the distinction between medullary thymic epithelial cells (TECs), cortical TECs, and Hassall bodies. Moreover, depleted thymus fragments cryopreserved for one year were recolonized by intrathymic injections of 3×106 thymocytes per mL, demonstrating the capability of these fragments to support T cell development. Thus, this technique opens up the possibility of freezing and storing large volumes of thymus tissue for immediate transplantation into patients with DiGeorge syndrome or atypical (Omenn-like) phenotype.

Endocrine, morphometric, and ultrasonographic characterization of neck adiposity in Andalusian horses.

Equine metabolic syndrome (EMS) can be diagnosed by hormonal measurements; however, it would be important to find simpler measurements that allow easy identification of affected or at risk individuals. In horses, the dorsal neck region is one of the most frequent anatomical sites for fat deposition and neck obesity has been linked to EMS. The aim of this study was to evaluate the association of hormonal markers of obesity (leptin) and insulin resistance (insulin) with morphometric and ultrasonographic neck measurements in Andalusian horses. Plasma leptin and insulin concentrations were measured by RIA in 127 Andalusian horses. Neck circumferences (NC) were measured at 3 equidistant locations at 25%, 50%, and 75% of neck length (NC-25%, NC-50%, and NC-75%). At the same 3 locations, subcutaneous fat thickness (SFT-25%, SFT-50%, and SFT-75%) was measured ultrasonographically. In the population under study, a tendency to adiposity was confirmed by the elevated plasma leptin levels (7.47 ± 5.03 ng/mL). However, plasma insulin concentrations (4.05 ± 3.74 µIU/mL) were within normal range in most horses. Our results indicate that NC showed significant sexual dimorphism and did not correlate well with hormonal measurements. Ultrasonographic assessment of fat thickness at the base of the neck (SFT-75%) was significantly correlated with both plasma leptin and insulin and did not show differences between males and females. Thus, in the search for a single objective parameter which can be used in large populations, SFT-75% is a potential candidate and may be a meaningful parameter to predict EMS.

BLM germline and somatic PKMYT1 and AHCY mutations: Genetic variations beyond MYCN and prognosis in neuroblastoma.

Neuroblastoma (NB) is the most common extra cranial solid tumor of childhood and often lethal in childhood. Clinical and biologic characteristics that are independently prognostic of outcome in NB are currently used for risk stratification to optimally the therapy. It includes age at diagnosis, International Neuroblastoma Staging System tumor histopathology and MYCN amplification. However, even in patients with theoretically good prognosis, such as localized tumor and non-amplified MYCN, either disease progress or recurrence may occur. Potential genetic determinants of this unfavorable behavior are not yet fully clarified. The presence of elevated expression of AHCY, PKMYT1, and BLM has accompanied poor prognosis MYCN-amplified neuroblastoma patients. Considering the potential implication of these genes on the clinical management of NB, we hypothesize that the identification of genetic variations may have significant impact during development of the recurrent or progressive disease. Using targeted DNA sequencing, we analyzed the mutation profiles of the genes PKMYT1, AHCY, and BLM in tumor samples of five patients with MYCN amplified and 15 MYCN non-amplified NB. In our study, BLM germline variants were detected in two patients with MYCN-non-amplified neuroblastoma. Our data allow us to hypothesize that, regardless of MYCN status, these mutations partially abolish BLM protein activity by impairing its ATPase and helicase activities. BLM mutations are also clinically relevant because BLM plays an important role in DNA damage repair and the maintenance of genomic integrity. We also found a novel variant in our cohort, PKMYT1 mutation localized in the C-terminal domain with effect unknown on NB. We hypothesize that this variant may affect the catalytic activity of PKMYT1 in NB, specifically when CDK1 is complexed to cyclins. The prognostic value of this mutation must be further investigated. Another mutation identified was a nonsynonymous variant in AHCY. This variant may be related to the slow progression of the disease, even in more aggressive cases. It affects the maintenance of the catalytic capacity of AHCY, leading to the consequent functional effects observed in the NB patients studied. In conclusion, our hypothesis may provide that mutations in BLM, AHCY and PKMYT1 genes found in children with MYCN-amplified or MYCN-non amplified neuroblastomas, may be associated with the prognosis of the disease.

Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015.

REASONS FOR PERFORMING STUDY: Andalusian horses have been proposed as a breed predisposed to equine metabolic syndrome (EMS) phenotype [1] because they are prone to exhibiting regional, generalised adiposity and tendency to laminitis [2]. Insulin dysregulation represents the main pathophysiological cause for all the features of EMS, however there are no epidemiological studies in this breed. OBJECTIVE: To assess insulin dysregulation through insulin proxies in Andalusian horses with different levels of obesity. STUDY DESIGN: Cross-sectional study. METHODS: One hundred and sixty-four Andalusians (78 stallions and 86 mares, 2-15 years) were scored for overall (body condition score, BCS) and neck (cresty neck score, CNS) adiposity. Grain concentrate was withheld for 12 h before sampling. Blood samples were collected between 06.00-10.00 h for basal glucose, insulin concentrations, RISQI and MIRG proxies calculation. Conditions were defined as: obese horses (Ob), BCS ≥ 7; cresty neck horses (CN), CNS ≥ 3; hyperinsulinaemia, insulin ≥20 µu/ml; low insulin sensitivity, RISQI<0.32[mu/l](-0.5) and increased insulin secretory response, MIRG>5.6muinsulin (2)/[10.l.mgglucose]. Regarding BCS 2 groups were created: Ob and non-Ob. These groups were subdivided depending on CNS: with CN and without it (nonCN). Ob-nonCN group (n = 2) was excluded for the statistics due to the low number of horses. RESULTS: Of the horses studied, 26.8% were Ob-CN, 42.1% were nonOb-CN and 31.1% were nonOb-nonCN. Ob horses presented higher insulin levels (P = 0.034) and lower RISQI values (P = 0.019) than all nonOb horses. When CN was considered, only RISQI was lower (P = 0.015) in Ob-CN group respect to nonOb-nonCN, however nonOb-CN group does not differ from the other 2 groups. Furthermore, the percentage of Ob-CN horses with hyperinsulinaemia (2.3%), abnormal RISQI (4.5%) and MIRG (9.1%) was very low. CONCLUSIONS: These results suggest that in Andalusians, increased adiposity was not clearly associated to insulin dysregulation and, similar to human beings, may coexist as a metabolically healthy but obese phenotype. Ethical animal research: Ethical University Committee approved all the procedures and owner informed consent was obtained. SOURCE OF FUNDING: None. Competing interests: None declared.

Visual Inspection for Caries Detection: A Systematic Review and Meta-analysis.

We aimed to perform a systematic review including a meta-analysis to evaluate the overall accuracy of visual methods for detecting carious lesions and to identify possible sources of heterogeneity among the studies included. Two reviewers searched PubMed, Embase, Scopus, and other sources through July 2014 to identify published and nonpublished studies in English. Studies of visual inspection were included that 1) assessed accuracy of the method in detecting caries lesions; 2) were performed on occlusal, proximal, or free smooth surfaces in primary or permanent teeth; 3) had a reference standard; and 4) reported sufficient data about sample size and accuracy of methods. The data were used to calculate the pooled sensitivity, specificity, diagnostic odds ratio, and summary receiver operating characteristics curve. Heterogeneity of the studies was also assessed. A total of 102 manuscripts (from 5,808 articles initially identified) and 1 abstract (from 168) met the inclusion criteria. In general, the analysis demonstrated that the visual method had good accuracy for detecting caries lesions. Although laboratory and clinical studies have presented similar accuracy, clinically obtained specificity was higher. We also observed moderate to high heterogeneity and evidence of publication bias in most papers. Moreover, studies employing widely recognized visual scoring systems presented significantly better accuracy as compared to studies that used their own criteria. In conclusion, visual caries detection method has good overall performance. Furthermore, although the identified studies had high heterogeneity and risk of bias, the use of detailed and validated indices seems to improve the accuracy of the method.

Alkane oxidation by a carboxylate-bridged dimanganese(III) complex.

A new manganese(II) oxamato dimer possesing an unprecedented Mn2(mu-O2CR)(mu-OH2...O2CR) core has been synthesised, structurally and magnetically characterised, and used as a catalyst for the oxidation of alkanes to alcohols and ketones by ButO2H and O2 in CH2Cl2 at rt.

Is nutritional anestrus precipitated by subfunctional corpora lutea in beef cows?

Thirty-four multiparous, lactating, cyclic beef cows which calved in moderate body condition were used to determine effects of restricted nutrition on corpus luteum (CL) development and endocrine status. At 78 d postpartum, six cows were assigned to a control (CON) diet (26.0 Mcal ME), fed to increase bodyweight (BW) and body condition score (BCS), and the remaining 28 cows were fed to lose BW and BCS on a restricted (RES) diet (14.0 Mcal ME). Following a 40-d adjustment period on respective diets, estrous cycles were synchronized and cows bled daily for determination of progesterone (P4), luteinizing hormone (LH) and insulin (INS) beginning at the synchronized estrus. Ultrasonography was used to determine the ovulatory follicle and CL development. Control cows were maintained for one estrous cycle and were ovariectomized on day 11 of their second cycle. Ten cows on restricted diet (RES-C) continued to form a functional CL (P4 > 1.5 ng/ml at day 10 of an estrous cycle) through as many as 5 cycles, after which observations were discontinued. Fourteen cows on restricted diet (RES-A) were ovariectomized on day 11 of a cycle when a CL was identified by ultrasonography, but was subfunctional (P4 < 1.5 ng/ml on day 10 of that cycle). Four additional RES-A cows which had subfunctional CL were not ovariectomized but were bled for an additional 25 d. At ovariectomy, CL and ovarian weights were collected. Luteal tissue was prepared for evaluation of P4 synthesis, LH responsiveness in vitro, and for determination of P4 content and total LH receptors. Bodyweight and BCS increased in CON cows; whereas, RES cows lost BW and BCS (P < .05). In the cycle prior to ovariectomy, serum P4 and LH were not different in 18 RES-A cows which developed subfunctional CL in comparison to CON cows. Four RES-A cows not ovariectomized but bled for an additional 25 d neither exhibited estrus, ovulated, nor had P4 concentrations greater than .3 ng/ml. Serum INS was lower in RES-A cows during the cycle prior to ovariectomy than in CON cows (P < .05). During the 11-d period prior to ovariectomy, mean serum P4 and INS were lower in RES-A cows than in CON cows (P < .05); however, serum LH was not different. Furthermore, CL and ovarian weights, P4 content of CL, secretion of P4 by luteal tissue in response to LH in vitro and LH receptor number were not different between CON and RES-A cows. In conclusion, nutritional anestrus may be preceded by the formation of a CL with lower steroidogenic output in vivo. However, luteal tissue, collected from RES-A cows, did not appear to be subfunctional during in vitro incubation when substrate availability and gonadotropin support were equal between diets.

Prolongation of the luteal phase by prostaglandin E(2) during the estrous cycle in the cow. A preliminary report.

An experiment was conducted to determine the effects of prostaglandin E(2) (PGE(2)) on ovarian progesterone secretion during the estrous cycle in the cow. Intraluminal uterine catheters were implanted in three beef cows (2 treated, 1 control), and 1.3 mg of PGE(2) were infused into the uterus every 4 hours from days 9 through 21 post-estrus. Blood samples were collected from the jugular vein at 2-hour intervals from days 9 to 21 and twice daily from day 22 to 28 post-estrus. Progesterone was measured by applying a specific, direct plasma radioimmunoassay in all samples without extraction. Intrauterine infusion with PGE(2) resulted in maintenance of luteal-phase progesterone secretion until day 21 post-estrus, 4 days after luteal regression occurred in the vehicle-treated cow. In this study, we demonstrated that PGE(2) can prolong the presence of luteal phase plasma progesterone concentrations by possibly stimulating in vivo steroidogenesis by the corpus luteum during the estrous cycle in the cow.

Estrogens and prostaglandin F2alpha in the semen and blood plasma of stallions.

A study was performed to determine the levels of estrogens and prostaglandin F2alpha in the stallion ejaculate. Simultaneous semen and blood plasma samples were collected from 19 stallions, 2 weeks apart, during the breeding season. Although not statistically different, the total mean estrogen content tended to be higher in seminal plasma (4447 pg/ml) than in blood (2497 pg/ml). A tendency was found for higher mean estrone sulphate concentrations than for total free steroid in both seminal (4116.1 vs 330.5 pg/ml) and blood plasma (2447.1 vs 49.5 pm/ml). Mean concentrations of estrone in ejaculate and blood plasma were 257.1+/-267.0 (SD) and 9.5+/-5.4 pg/ml, respectively. Estradiol-17beta concentrations were 73.4+/-87.4 and 40.0+/-27.6 pg/ml in ejaculates and blood plasma, respectively. Mean PGF2alpha concentrations tended to be much higher than total estrogens (1106.8+/-1636.4, SD, vs approximately 260 ng/ejaculate, respectively). To our knowledge this is the first report of PGF2alpha and estrogen concentrations in the stallion ejaculate.

Suckling induced cortisol secretion in young beef cows.

The profiles of plasma cortisol concentration in response to suckling were determined in 10 young, postpartum beef cows between days 25 and 85 postpartum. Two trials, comprised of five cows each, were conducted in the fall (I) and spring (II), respectively. In both trials, plasma cortisol rose within 10 minutes after suckling began and was significantly higher than pre-suckling concentrations (P<.01). Over the next 30 minutes in trial I and 40 minutes in trial II, the cortisol level progressively fell back to the pre-suckling levels. This profile was qualitatively similar among the days postpartum on which the cows were bled. Neither the profile nor the peak concentration after suckling changed significantly (P>.10) as days postpartum lapsed. Finally, there was a significant difference (P<.01) in mean plasma cortisol between the cows in trial I compared to the cows in trial II.

Effect of holding time and temperature of bovine whole blood on concentration of progesterone, estradiol-17beta and estrone in plasma and serum samples.

Bovine jugular venous blood was collected, with and without heparin, and aliquoted into 140 12-ml tubes. Four subsamples (two heparinized and two coagulated) were centrifuged immediately (time zero) and plasma or serum was aspirated and stored at -20 degrees C. One-half of the remaining subsamples were stored at 4 degrees C and the other one-half at 25 degrees C (room temperature). At 1-h intervals (0 to 24 h), 6-h intervals (24 to 72 h) and at 96 and 120 h, four subsamples (heparinized and coagulated at both 4 degrees C and 25 degrees C) were centrifuged, plasma or serum was aspirated and stored at -20 degrees C. Whole blood incubation for 1 h at 25 degrees C reduced mean plasma and serum progesterone (P(4)) concentration (P<0.05). Similarly, whole blood incubation at 4 degrees C for 2 and 3 h, respectively, reduced mean plasma and serum P(4) concentration (P<0.05). No difference was found in mean P(4) concentration between plasma and serum samples harvested from whole blood incubated at 4 degrees C or 25 degrees C. Concentration of estradiol-17beta (E(2)) and estrone (E(1)) fluctuated over time, irrespective of holding temperature. There was a blood type, heparinized or coagulated, by time interaction (P<0.01) for both E(2) and E(1) concentrations It was concluded that incubation time and temperature between collection and centrifugation of bovine blood samples influenced the assayable P(4) concentration in both plasma and serum. In contrast, incubation temperature had no effect on assayable E(2) and E(1) concentrations, but assayable E(2) and E(1) over time were differentially affected, depending on whether plasma or serum was assayed.

Prolactin and luteinizing hormone (LH) release throughout the postpartum period in the suckled first-calf beef cow.

A study was performed to examine the release patterns of prolactin and LH of young beef cows with one (single calf) or two calves (double calf) throughout the postpartum interval. The effect on prolactin release of intramuscular and intra-carotid administration of lergotrile and intra-carotid administration of L-dopa was also examined. In approximately 50% and 65% of the cases, no prolactin release could be detected after the beginning of or during the suckling stimulus in cows with one or two calves respectively. LH plasma concentrations remained constant throughout the experiment in all animals. The chosen intramuscular lergotrile treatment lowered plasma prolactin concentrations to baseline levels but had no effect on the length of the postpartum interval. No effect on prolactin release was observed by the given intra-carotid treatments of both lergotrile and L-dopa. First postpartum estrus was observed on days 67 and 88 in the single and double calf cows respectively. The number of suckling periods did not change during the postpartum period but their duration decreased during the same period. These results demonstrate that in at least half of the cases the suckling stimulus does not cause a release of prolactin from the pituitary in the young beef cow. Also, the inhibitory effect of suckling on the resumption of ovarian cyclic function postpartum appears to be of a quantitative nature and mediated by a factor other than prolactin.

Influence of phospholipids on ruminal fermentation in vitro and on nutrient digestion and serum lipids in sheep.

Phospholipid supplements were incubated in vitro or fed to sheep to determine how they affected ruminal fermentation, nutrient digestion and serum lipid concentration. In vitro, deoiled soybean lecithin added to hay increased (P less than .05) total VFA concentration but had no effect on fiber digestion in four of five trials. Purified phospholipid (synthetic phosphatidylethanolamine), however, had little effect on in vitro hay fermentation when tested at four levels (0, 10, 20 or 30 mg) in three separate trials. Deoiled soybean lecithin disappeared in vitro at two rates, 12.9 and .66%/h for the fast- and slow-degrading fractions, respectively. Compared with 2.4% corn oil supplements, 5.2% soybean lecithin added to sheep diets (56% concentrate) reduced (P less than .05) energy, fiber and nitrogen digestibilities. Crude lecithin reduced (P less than .05) energy digestibility more than deoiled lecithin. Both types of lecithin increased (P less than .05) serum nonesterified fatty acid concentrations but had no effect on serum glucose, cholesterol or triglyceride concentrations compared with the corn oil diet. In summary, phospholipids had different effects on ruminal fermentation, depending on their source. None had a beneficial effect on fiber digestion. Phospholipids are degraded in the rumen and inhibit digestion in a manner similar to that of the commercial fats and oils.

Trenbolone, estradiol-17 beta and estrone levels in plasma and tissues and live weight gains of heifers implanted with trenbolone acetate.

Twenty-four heifers were allotted into three groups of eight heifers each and designated control, long-term (LT) or short-term (ST). Animals in the latter two groups were implanted in the ear with 300 mg trenbolone acetate (TBA) for 99 or 62 d, respectively. Four heifers in each group were subjected to liver and fat biopsy 60 d after initiation of the experiment. At slaughter, which occurred 15 d after retrieval of the implant, liver and fat were also collected. The implant was analyzed for residual trenbolone (TBOH), and tissues were analyzed for TBOH and estradiol-17 beta (E2 beta). Blood samples were taken weekly after implantation and daily for 14 d before and after implantation. All heifers were weighed weekly. The ST heifers gained faster (P less than .05) than the control or the LT heifers, whereas the LT heifers gained similarly to the controls. Plasma levels of TBOH rose to over 900 pg/ml in response to the implantation in both treated groups, but stabilized at a lower level in the ST group than in the LT group. In both groups plasma E2 beta rose to over 7.5 pg/ml in response to TBA implantation; in fact, a regression analysis of E2 beta on TBOH in individual cows showed that the two hormones varied directly. Fat and liver accumulated substantial TBOH during implantation, but it cleared rapidly during the 15 d withdrawal period. Indications from this experiment are that TBA has promise for promoting rate of gain and efficiency of feed utilization in feedlot heifers. No undesirable effects on carcass quality were detected. The drug cleared blood and tissues rapidly after the implant was withdrawn. Further research is needed to determine the most effective implantation schedule. It would be desirable to determine whether a positive response to TBA will occur in animals being finished predominantly on forages.

Use of the GnRH analogue, deslorelin acetate, in a slow-release implant to accelerate ovulation in oestrous mares.

In two separate controlled clinical trials, the efficacy and safety of 2.2 mg of the GnRH analogue deslorelin, administered subcutaneously as a short-term implant to normally cycling mares in oestrus with a dominant ovarian follicle more than 30 mm in diameter, were evaluated, using a placebo as a negative control. The oestrous cycle of each mare was followed by teasing, palpation per rectum and transrectal ultrasonography. Follicles were monitored every 24 hours by ultrasonography until ovulation occurred. The mares were either mated naturally or inseminated artificially. In trial 1, 174 mares were treated at six locations in Canada, and in trial 2, 98 mares were treated at three locations in the USA. In trial 1, the treatment with deslorelin reduced the mean (sd) time to ovulation from 84.2 (48.4) hours to 50.2 (19.6) hours (P < 0.001) and in trial 2 it reduced it from 88.8 (40.3) hours to 54.1 (26.5) hours (P < 0.001). In trial 1, the percentage of mares ovulating within 48 hours increased from 37.7 per cent in control mares to 86.1 per cent in treated mares (P < 0.001) and in trial 2 the percentage increased from 26.5 to 80.9 per cent (P < 0.001). In trial 2, the duration of oestrus in the deslorelin-treated mares was reduced from 6.1 days to 4.3 days and the number of matings or artificial inseminations was reduced from 2.5 to 1.7 (P < 0.001). In trial 1, days 12 to 20 pregnancy rates for matings at the treatment oestrus were not different for deslorelin-treated (75.6 per cent) and placebo-treated (66.1 per cent) mares. In trial 2, days 12 to 20 pregnancy rates from matings at the treatment oestrus were lower for deslorelin-treated (58.7 per cent) than for placebo-treated (83.3 per cent) mares (P < 0.05), although pregnancy rates were similar for deslorelin-treated (97.1 per cent) and placebo-treated (95.0 per cent) mares after mating at the second oestrus. In both trials, pregnancy losses due to early or late abortions were within the normally expected range and similar for deslorelin-treated (3.6 and 3.7 per cent, respectively) and placebo-treated (13.4 and 7.5 per cent) mares. The treatments did not cause systemic side effects and local reactions at the implantation sites were slight and of short duration.