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61.
This study aimed to evaluate the effect of the exogenous recombinant bovine somatotropin (rbST) on plasma concentrations of insulin‐like growth factor I (IGF‐I), insulin and semen quality of bulls. Twenty bulls (Aberdeen Angus and Brangus) were divided by breed into two groups. Placebo group was injected with NaCl 0.9% (s.c.) and treatment group with rbST (s.c., 500 mg) at days 0 and 14 of the experiment. Immediately after semen collection, blood samples were taken on days 0, 14, 28, 42 and 56 of the experiment. Semen was also collected on day 70 of the experiment. Evaluation of sperm motility was performed at pre‐freezing and post‐thawing stage, whereas assessment of sperm membrane integrity was performed after freezing and thawing. Analysis of data revealed that the effect of treatment and treatment‐by‐collection day on plasma concentrations of IGF‐I and insulin was not significant. However, mean plasma concentrations of IGF‐I and insulin were affected (p < 0.0001) by days of blood sampling. Effect of treatment and treatment‐by‐collection day on motility of spermatozoa was similar (p > 0.05) at pre‐freezing and post‐thawing stage. Intactness of plasmalemma and tail membrane of spermatozoa at post‐thawing stage was higher (p < 0.05) in rbST‐treated group than in control. In conclusion, rbST did not affect plasma concentrations of IGF‐I and insulin, however, it did improve post‐thaw sperm membrane integrity.  相似文献   
62.
Drought is becoming a major threat to rice farming across the globe owing to the depletion of water tables in rice-growing belts. Drought affects rice plants at multiple stages, causing damage at morphological and physio-biochemical levels, leading to severe losses that exceed losses from all other stresses. The amalgamation of conventional breeding methods with modern molecular biology tools and biometrical methods could help accelerate the genetic gain for drought tolerance in rice. Many drought-tolerance traits with genetic determinants have been identified and exploited for tolerance rice variety breeding. The integration of genome-wide association study and genomic selection tools with speed breeding shortened the breeding cycle and aided in rapid improvement of genetic gain. In this review, we emphasized the progress made through classical breeding as well as the limitations and usefulness of current genomic methods in improving drought tolerance. We briefly addressed methods for identifying genetic determinants for drought tolerance and deploying them through genomics-assisted breeding programmes to develop high-yielding drought-tolerant rice cultivars.  相似文献   
63.

Background

Effective treatments for dogs with advanced stage mast cell tumors (MCT) remain a pressing need. A micellar formulation of paclitaxel (paclitaxel [micellar]) has shown promise in early‐phase studies.

Hypothesis/Objectives

The objective was to demonstrate greater activity for paclitaxel (micellar) compared with lomustine. The null hypothesis was μp = μL (ie, proportion of responders for the paclitaxel [micellar] and lomustine groups, respectively).

Animals

Two hundred and fifty‐two dogs with advanced stage nonresectable grade 2 or 3 MCT.

Methods

Prospective multicenter randomized double‐blind positive‐controlled clinical trial. The primary endpoint was confirmed overall response rate (CORR) at 14 weeks. A secondary endpoint, biologic observed response rate (BORR), also was calculated. Safety was assessed by the characterization and grading of adverse events (AE).

Results

Overall CORR (7% versus 1%; = .048) and BORR (23% versus 10%; = .012) were greater for paclitaxel (micellar) compared with lomustine. Paclitaxel (micellar)‐treated dogs were 6.5 times more likely to have a confirmed response and 3.1 times more likely to experience a biologic observed response. The majority of AE with paclitaxel (micellar) were transient and clinically manageable. Twenty‐seven dogs (33%) receiving lomustine were discontinued because of hepatopathy compared with 3 dogs (2%) receiving paclitaxel (micellar) (< .0001; odds ratio 26.7).

Conclusions and Clinical Importance

Paclitaxel (micellar)'s activity and safety profile are superior to lomustine. The addition of an active and novel taxane to the veterinary armamentarium could fill a substantial need and, as its mechanism of action and AE profile do not overlap with currently available TKI, its availability could lead to effective combination protocols.  相似文献   
64.
65.

Purpose

Human-mediated landscape changes alter habitat configuration, which strongly structures animal distributions and interspecific interactions. The effects of anthropogenic disturbance on predator–prey relationships are fundamental to ecology, yet less well understood. We determined where predation events occurred for fawn and adult female mule deer from 2008 to 2014 in critical winter range with extensive energy development. We investigated the relationship between predation sites, energy infrastructure, and natural landscape features across contiguous areas experiencing different degrees of energy extraction during periods of high and low intensity development.

Methods

We contrast spatial correlates of 286 mortality locations with random landscape locations and mule deer distribution estimated from 350,000 GPS locations. We estimated predation risk with resource selection functions and latent selection difference functions.

Results

Relative to the distribution of mule deer, predation risk was lower closer to pipelines and well pads, but higher closer to roads. Predation sites occurred more than expected relative to availability and deer distribution in deeper snow and non-forested habitats. Anthropogenic features had a greater influence on predation sites during the period of low activity than high activity, and natural landscape characteristics had weaker effects relative to anthropogenic features throughout the study. Though canids accounted for the majority of predation events, felids exhibited stronger landscape associations, driving the observed spatial patterns in predation risk to mule deer.

Conclusions

The emergence of varied interactions between predation and landscape features across contexts and years highlights the complexity of interspecific interactions in highly modified landscapes.
  相似文献   
66.
A retrospective analysis was done to assess the toxicity and efficacy associated with an alternating chemotherapy protocol of ifosfamide (375 mg m?2) and doxorubicin (30 mg m?2) for adjuvant treatment of 39 dogs with sarcomas. Twelve dogs had various soft‐tissue sarcomas and 27 dogs had hemangiosarcoma (HSA). Complete blood counts were evaluated 7 days after the first dose of ifosfamide and doxorubicin. One dog had grade 4 neutropenia (<500 µL?1) after treatment with ifosfamide and one dog had grade 3 neutropenia (500–1000 µL?1) after treatment with doxorubicin. One dog treated with doxorubicin was hospitalized for 24 h due to vomiting. The median survival time (ST) for the 27 dogs with HSA treated by surgery and with doxorubicin/ifosfamide was 149 days (mean 366 days). Although the protocol of alternating ifosfamide and doxorubicin was well tolerated, it failed to result in a statistically significant improvement in the ST when compared to a historical population of dogs with stage 2 splenic HSA treated by surgery alone.  相似文献   
67.
Use of compounded L‐asparaginase became routine in veterinary oncology when manufacturing of Elspar® was discontinued in 2012. The objective of this study was to evaluate the safety of compounded L‐asparaginase (CLASP, KRS Global Biotechnology, Boca Raton, FL, USA) in comparison with Elspar® (Lundbeck LLC, Deerfield, IL, USA). In addition, we documented the response to CLASP in combination with a corticosteroid in this population of dogs with lymphoma. Dogs were prospectively treated with 10 000 IU/m2 CLASP or Elspar® subcutaneously. Corticosteroids were administered concurrently. Adverse events (AE) were assessed according to the Veterinary Cooperative Oncology Group Common Terminology Criteria for Adverse Events v1.1 (VCOG‐CTCAE). Response was recorded. Seventy‐three dogs received 75 treatments (CLASP, n = 47; Elspar®, n = 28). No AE were attributed to CLASP. Grade I and II AE probably or possibly related to treatment were observed following two Elspar® treatments. The overall response rate to the combination of CLASP and a corticosteroid was 80% (24% CR and 56% PR). In combination with a steroid, the compounded L‐asparaginase evaluated in this study is safe and demonstrates activity against canine lymphoma. In the face of the discontinuation of Elspar®, veterinarians should seek compounded LASP products that have been tested for activity, purity, and sterility.  相似文献   
68.
This study tested a model for predicting reproductive status from in-line milk progesterone `measurements. The model is that of Friggens and Chagunda [Theriogenology 64 (2005) 155]. Milk progesterone measurements (n = 55 036) representing 578 lactations from 380 cows were used to test the model. Two types of known oestrus were identified: (1) confirmed oestrus (at which insemination resulted in a confirmed pregnancy, n = 121) and (2) ratified oestrus (where the shape of the progesterone profile matched that of the average progesterone profile of a confirmed oestrus, n = 679). The model detected 99.2% of the confirmed oestruses. This included a number of cases (n = 16) where the smoothed progesterone did not decrease below 4 ng/ml. These cows had significantly greater concentrations of progesterone, both minimum and average, suggesting that between cow variation exists in the absolute level of the progesterone profile. Using ratified oestruses, model sensitivity was 93.3% and specificity was 93.7% for detection of oestrus. Examination of false positives showed that they were largely associated with low concentrations of progesterone, fluctuating around the 4 ng/ml threshold. The distribution of time from insemination until the model detected pregnancy failure had a median of 22 days post-insemination. In this test, the model was run using limited inputs, the potential benefits of including additional non-progesterone information were not evaluated. Despite this, the model performed at least as well as other oestrus detection systems.  相似文献   
69.
70.
The objective of this study was to detect the reasons of rooster's fertility decrease at 50 weeks of age. Therefore, the reproductive system of broiler breeder roosters was laparoscopic, macroscopic and histopathology evaluated, and a comparison of the anatomical aspect with the sperm analysis and birds’ age was realized. Cobb roosters (n = 59) were distributed into two groups (30 and 50 weeks). Evaluations were performed with laparoscopy, macroscopy and histopathology, and seminal quality, blood serum testosterone concentration and weight were also determined. The old roosters presented smaller testicle size, higher intensity epididymal lithiasis and lower testicle sperm production, compared to the young roosters. The use of the endoscope could easily distinguish a normal‐sized testicle than an atrophic one. Four old roosters with severe testicular atrophy did not show spermatogenesis, although three still had sperm in the ejaculate. This would falsely indicate a wrong diagnosis of normal fertility before the testicular atrophy took place. In conclusion, in addition to the weight increase with age, the testicular atrophy and impairment of sperm production seemed to be the main reason to the decrease in the rooster's fertility at 50 weeks of age. Therefore, the use of the laparoscopy as a way to detect the roosters with testicular atrophy before 50 weeks of age and their removal from them flock could be useful as a diagnostic tool to prevent the birds’ fertility loss.  相似文献   
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