Bovine Reproduction. Группа авторов. Читать онлайн. Newlib. NEWLIB.NET

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Издательство: John Wiley & Sons Limited
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recorded in all regions.

Schematic illustration of the SFT electronic BBSE form.

      Source: From Society for Theriogenology, Bull Breeding Soundness Evaluation form. © 1992, The Society for Theriogenology.

      Below the client and bull information, a box is provided to record any known history about the bull's fertility or medical history. Practitioners utilizing the SFT electronic BBSE software can allow automatic filling of this box with the bull's previous breeding soundness examination if it was completed in the software. At the bottom of the box there is a statement regarding the fact that the responsibility is on the producer to evaluate the libido and mating ability of the bull when placed with females.

      SC is part of the reproductive physical examination and is recorded in centimeters just below the physical examination checkboxes on the form. Tables of the expected SC by age are given on the back of the form. In the SFT system, a bull with an SC below the minimum cannot receive the classification of satisfactory potential breeder even if the rest of the physical examination is passed and semen quality is satisfactory.

      When filling in the semen examination portion of the form, the method of semen collection is marked, followed by whether the bull obtained erection, full protrusion of the penis, and ejaculation. Protrusion of the penis and examination of the prepuce is essential before deeming a bull a satisfactory potential breeder in this system.

      The SFT manual provides good detail on preparing semen for evaluation so that repeatable results can be achieved. These guidelines describe the common requirement to dilute concentrated samples in order to assist visualization of individual spermatozoa for motility assessment. But there is little detail on the practicalities of the dilution process and dilution rates.

      The SFT lower threshold for individual motility is set at 30%. It is notable that the measurement of gross motility is no longer recommended as part of the BBSE semen assessment process in the current SFT guidelines.

      The SFT no longer classifies morphology defects as primary/secondary or major/minor, but simply records them as they are seen. They are then grouped into Normal or Abnormal Head, Midpiece, and Tail categories for the report. If there is a high percentage of abnormal sperm, notes on what was found are made in the comments. The SFT lower threshold for normal sperm is 70%.

      Following the evaluation, the data are interpreted and the bull is classified into one of three categories – satisfactory potential breeder; classification deferred; or unsatisfactory potential breeder. The classification deferred category is used when potentially treatable abnormalities are detected, or when the practitioner considers that aberrations to the spermiogram may be related to a specific insult and time is needed for recovery.

      Australia

      The BBSE process within Australia has oversight from the Australian Cattle Veterinarians (ACV), with input from the Australian Reproduction Veterinarians (ARV). From the 1970s to the end of the 1990s, BBSEs in Australia were broadly based on the SFT recommendations. Yet, there was variation throughout the veterinary profession in the ability to reliably collect data, the depth of the evaluation, the interpretation of findings, and the quality of reporting [11]. However, over these three decades, there was a steady progression to a more standardized approach as information was disseminated throughout the veterinary profession via improved undergraduate training and continuing professional education. There was also a push from industry stakeholders to ensure consistency in the process, particularly prior to Breed Society sales of young bulls. This consistency was essential so that bull producers could have confidence their bulls were not disadvantaged at sale‐time due to variation between veterinarians in data collection or interpretation. In 2002 there was a major progression toward improving the quality and consistency of BBSEs with the ACV commitment to implement a BBSE accreditation scheme for veterinarians [12].

      Prior to the implementation of the BBSE accreditation scheme by the ACV in 2007 came an overhaul of the BBSE processes. Initially, the scientific literature was reviewed [13] and the needs of stakeholders were considered in preparing the substantive manual Evaluating and Reporting Bull Fertility [14] that outlined standards for assessing and reporting bull breeding soundness. A further progression was the development of software to assist with the recording, interpretation, and reporting of the process [15].

      Driven by legal advice and industry requirements, the ACV elected to develop the BBSE process to provide a description of risk, rather than reporting an overall result for the bull. Therefore the BBSE process was divided into five fertility categories, with results for each individual category reported on the certificate. The results provide information on whether the minimum standards for each category were assessed, or met, but the bull is not given an overall Pass/Fail classification.

Schematic illustration of an example of the BBSE report from the Australian system.

      Source: From AVA, BBSE report from the Australian system, © Australian Veterinary Association Ltd.

      The SC is reported in centimeters. The results for all other categories are reported as either a T (Tick), Q (Qualified), X (Cross), or NT (Not Tested). As with the SFT system, the option to report a category as “Q” is chosen if aberrations deemed to be treatable are encountered. Professional, standardized, easy‐to‐read reports are produced electronically. There are no booklet recording options, but the veterinarian can print out customized field recording sheets for each job once the client and job details have been entered into the database. There is also the option for