Effect of a Single Injection of Long-acting Progesterone on the First Ovulation in Early and Late Spring Transitional Mares     

Simon A. Staempfli  Sarah Clavier  Don L. Thompson  Patrick J. Burns  Sara K. Lyle  Angus O. McKinnon 《Journal of Equine Veterinary Science》2011,31(12):744-748

Since 1966, exogenous progestins have been used in equine practice for pregnancy maintenance, estrous suppression, and control of erratic sexual behavior. This study was designed to investigate the use of a new compounded controlled-release progesterone preparation (BioRelease P4 LA 300) in early and late spring transitional mares. In the first experiment, the pharmacodynamic properties of the preparation were studied in five geldings. In the second experiment, the use of a single intramuscular injection (600 mg) was tested in 68 embryo-recipient mares maintained under natural photoperiod in the Southern Hemisphere. Experiment 1 demonstrated elevated serum concentrations of progesterone (>1 ng/mL) for 7.6 ± 2.2 days. In experiment 2, there was no effect of treatment in mares that were treated on September 18, independent of their follicular status at day of treatment (10 to 15 mm; 20 to 25 mm, respectively). When mares with a follicular size of 20 to 25 mm were treated on October 14, significantly more progestin-treated mares (10/12; 83%) ovulated between 10 and 24 days after treatment than untreated controls (3/12; 25%) (P < .05). Additionally, there was a trend in mares treated on October 14 for a shorter treatment to ovulation interval (mean ± SD, 18.6 ± 8.7 days) compared with untreated controls (mean ± SD, 26.7 ± 14.7 days) (P = .07). Administration of one single injection of long-acting progesterone is a simple and effective method of controlling the first ovulation of the season in late transitional mares.  相似文献   

Characterizing the molecular structure features of newly developed hulless barley cultivars with altered carbohydrate traits (Hordeum vulgare L.) by globar-sourced infrared spectroscopy in relation to nutrient utilization and availability     

Ling Yang  John J. McKinnon  David A. Christensen  Aaron D. Beattie  Peiqiang Yu 《Journal of Cereal Science》2014

Four newly developed huless barley cultivars with altered carbohydrate traits were developed at the Crop Development Centre (CDC), University of Saskatchewan which varied for amylose (1–40% DM), and β-glucan (5–10% DM) content. The four hulless barley cultivars include zero-amylose waxy, CDC Fibar; 5%-amylose waxy, CDC Rattan; normal-amylose, CDC McGwire and high-amylose, HB08302. CDC Copeland was also included as a hulled barley control. Our previous study revealed the altered carbohydrate traits in barley affected nutrition availability and rumen degradation kinetics. These biological differences may be caused by differences in their molecular structure features. The objectives of this study were to (1) reveal molecular structure features in the four hulless barley cultivars with altered carbohydrate traits, and (2) quantify the molecular structural features in relation to rumen degradation kinetics, intestinal nutrient digestion and predicted protein supply to dairy cattle. Conventional Molecular Infrared-vibration Spectroscopy was applied to detect biochemical characteristics of functional group bands including protein, non-starch carbohydrate (β-glucan and cellulosic compounds) and total carbohydrate. Spectral data were further analyzed using univariate analysis of recording absorption peak parameters (baseline, region, relative height and area) and also multivariate analysis with agglomerative hierarchical cluster analysis and principal components analysis. Although correlation results showed weak correlation (P < 0.05) between identified functional group bands and ruminal degradation kinetics and estimated protein supply from both models, molecular structure differences of hulless barley cultivars can still be detected by the Molecular Infrared-vibration Spectroscopy technique and potential truly protein supply (MP) was significantly affected (P < 0.05) by protein molecular structure characteristics in hulless barley cultivars.  相似文献   

Effect of Estradiol and Progesterone on Metabolic Biomarkers in Healthy Bitches     

A Tvarijonaviciute  JD Carrillo‐Sanchez  JJ Ceron 《Reproduction in domestic animals》2013,48(3):520-524

The aim of this study was to evaluate the possible association between hormonal changes that occur during oestrus and biomarkers related with glucose metabolism (glucose and insulin), lipid metabolism (lipidic profile and BChE) and adipokines (adiponectin and ghrelin) in healthy bitches. For this purpose, we measured these analytes in serum of bitches, at two times: before (T1) and after (T2) the LH peak that were established according to progesterone concentrations. Increased levels of total cholesterol (p < 0.01), high density lipoprotein cholesterol (HDL‐C) (p < 0.01), low density lipoprotein cholesterol (LDL‐C) (p < 0.01), adiponectin (p < 0.01) and ghrelin (p < 0.05) were observed at T2 in comparison with T1. No statistically significant changes were observed in serum glucose, insulin, homoeostasis model assessment for insulin sensitivity (HOMA), triglycerides and BChE. When all data of T1 and T2 were pooled, serum adiponectin showed positive correlation with progesterone (r = 0.353; p = 0.022) and HDL‐C (r = 0.307; p = 0.048), and negative with insulin (r = ?0.429; p = 0.005), HOMA (r = ?0.446; p = 0.003) and BChE (r = ?0.522; p < 0.001). Ghrelin showed negative correlation with estradiol (r = ?0.701; p = 0.004). BChE was negatively correlated with estradiol (r = ?0.441; p = 0.018) and glucose (r = ?0.343; p = 0.028), and positively with insulin (r = 0.460; p = 0.003) and HOMA (r = 0.505; p < 0.001). In conclusion, changes in metabolic biomarkers occur in bitches after LH peak, characterized by increased lipids (total cholesterol, HDL cholesterol and LDL cholesterol) without changes in BChE activity, and increased adiponectin and ghrelin concentrations, without significant changes in glucose and insulin.  相似文献   

A feline anaesthetic death associated with equipment incompatibility     

BJ O'Hagan  C McKinnon 《Australian veterinary journal》2013,91(12):505-506

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Oestrous Synchronization,Ovarian Superovulation and Intraspecific Transfers From a Closed Breeding Colony of Inbred SLA Miniature Pigs     

JJ Arlaud  L Baker  RL Williams  AJ French 《Reproduction in domestic animals》2010,45(6):951-958

The inbred SLA miniature pig is a unique animal model developed for organ transplantation studies and pre‐clinical experimental purposes. Reported oestrous synchronization and superovulation treatments were examined in two SLA haplotypes (AA and DD) to allow collection of embryos for both practical embryo transfer and experimental technologies from a closed breeding colony. Pre‐puberal miniature pigs were poor responders to oestrous synchronization treatments, while post‐puberal sows were equivalent to commercial sows. Following superovulation, the ovulation number (corpora .hemorrhagica) was higher (p < 0.05) in the cycling sows when compared with non‐cycling sows. Ovulations were equivalent to commercial pre‐puberal gilts and non‐cycling sows (p > 0.05). No difference in ovulation number between haplotypes was observed, which differs from the previous report (DD>AA). Collection of zygotes for pronuclear injection was the highest in the non‐cycling post‐puberal miniature pig group (p < 0.05), although significantly lower when compared with the commercial pig treatment groups (p < 0.05). The incidence of cystic endometrial hyperplasia in our colony was equivalent to rates observed in commercial pigs. Pronuclear visualization following centrifugation was the highest in the non‐cycling miniature sow group and approximates to about 25% of ovulations and about half the rate observed in the commercial pigs (50%). Miniature pig embryos transferred between SLA haplotypes and transfer of DD embryos to commercial pigs resulted in live births at a higher efficiency than previously reported. This study demonstrates the feasibility of undertaking assisted reproductive technologies in a closed breeding colony of inbred SLA miniature pigs without compromise to the breeding programmes.  相似文献   

The potential for gene flow from exotic eucalypt plantations into Australia's rare native eucalypts     

Robert C. Barbour  Sascha L. Wise  Gay E. McKinnon  René E. Vaillancourt  Grant J. Williamson  Brad M. Potts 《Forest Ecology and Management》2010

Hybridisation through pollen dispersal from exotic plants is increasingly recognised as a threat to the genetic integrity of native plant populations. Its genetic impact can be greater in rare taxa, due to their vulnerability to pollen swamping by more abundant congeners. We assessed the likelihood of pollen dispersal from exotic eucalypt plantations into all of Australia's rare native eucalypts, and conducted a case study of Eucalyptus perriniana, which is rare in Tasmania. The Australia-wide study involved spatial analyses of the locations for each rare species superimposed on distributions of eucalypt plantations, which were combined with known taxonomically based reproductive barriers. Of the 74 nationally listed rare eucalypt taxa, 22 had locations within 10 km of plantations of the same genus, and eight were within 1 km. These eight proximal taxa are considered priorities for monitoring. In the most extreme case, 30% of point locations originating from herbarium records and field surveys for Eucalyptus conglomerata were within 1 km of exotic plantations. In the case study, E. perriniana revealed considerable reproductive compatibility with adjacent recently established Eucalyptus nitens plantations. However, F₁ hybridisation between these species was limited, with 0.2% of the 18,625 seedlings grown from 100 single-tree open-pollinated seedlots being hybrids. For now, the probability of exotic gene flow into E. perriniana appears to be low, however this probability is likely to increase as more E. nitens flowers in the surrounding landscape. These studies suggest that understanding the breeding system and biology of these populations may reveal surprising resistance to such exotic hybridisation as well as identifying high risk situations to focus conservation management.  相似文献   

Egg production and naupliar growth of the tropical copepod Pseudodiaptomus australiensis in culture          下载免费PDF全文

Felipe Gusmão  A D McKinnon 《Aquaculture Research》2016,47(5):1675-1681

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Transurethral removal of a cystic urolith in a mare using a laparoscopic specimen pouch          下载免费PDF全文

AJ Williamson  AO McKinnon 《Australian veterinary journal》2017,95(5):174-177

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Evaluation of rumen fatty acid hydrogenation intermediates and differences in bacterial communities after feeding wheat- or corn-based dried distillers grains to feedlot cattle     

Aldai N  Klieve AV  Dugan ME  Kramer JK  Ouwerkerk D  Aalhus JL  McKinnon JJ  McAllister TA 《Journal of animal science》2012,90(8):2699-2709

The effect of partially replacing rolled barley (86.6% of control diet) with 20% wheat dried distillers grains plus solubles (DDGS), 40% wheat DDGS, 20% corn DDGS, or 40% corn DDGS (dietary DM basis) on rumen fluid fatty acid (FA) composition and some rumen bacterial communities was evaluated using 100 steers (20 per treatment). Wheat DDGS increased the 11t- to 10t-18:1 ratio (P < 0.05) in rumen fluid and there was evidence that the conversion of trans-18:1 to 18:0 was reduced in the control and wheat DDGS diets but not in the corn DDGS diet. Bacterial community profiles obtained using denaturing gradient gel electrophoresis and evaluated by Pearson correlation similarity matrices were not consistent for diet and, therefore, these could not be linked to different specific rumen FA. This inconsistency may be related to the nature of diets fed (dominant effect of barley), limited change in dietary composition as the result of DDGS inclusion, large animal-to-animal variation, and possibly additional stress as a result of transport just before slaughter. Ruminal densities of a key fiber-digesting bacteria specie that produces 11t-18:1 from linoleic and linolenic acids (Butyrivibrio fibrisolvens), and a lactate producer originally thought responsible for production of 10t,12c-18:2 (Megasphaera elsdenii) were not influenced by diet (P > 0.05).  相似文献   

Inbreeding and Reproduction in Endangered Ungulates: Preservation of Genetic Variation through the Organization of Genetic Resource Banks   总被引：1，自引：0，他引：1  

ERS Roldan  M Gomendio  JJ Garde  G Espeso  S Ledda  F Berlinguer  A del Olmo  AJ Soler  L Arregui  C Crespo  R González 《Reproduction in domestic animals》2006,41(S2):82-92

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