Manual of Animal Andrology

Peter J Chenoweth, Steven P. Lorton, Peter J Chenoweth, Steven P. Lorton

• Publisher: CAB International
• Year: 2022
• ISBN:
  9781789243529
• Topic: Medicina
• Subtopic: Medicina veterinaria

A succinct reference for those assessing and managing the reproductive functionality of male animals, this practical manual contains both generic and species-specific information suitable for widespread worldwide application. It covers all relevant aspects such as handling and restraint, physical examination, reproductive examination, important reproductive diseases, biosecurity, semen collection and its assessment, mating behaviour, and the fundamentals of semen handling and preservation for artificial breeding.A simple, concise 'go-to' for the useful techniques and procedures of animal andrology, this book: - Covers a wide range of species, including cattle, sheep, goats, pigs, horses, water buffalo, camelids and dogs- Provides normal values and ranges for important male reproductive traits, as well as guidelines for breeding soundness evaluations- Includes extra supplementary illustrations, protocols and resources through accompanying website to enable further learning.With information presented in a manner that will remain useful for years to come, Manual of Animal Andrology is an essential resource for veterinarians, theriogenologists, animal breeders, and students of veterinary and animal sciences.

1 Concepts and Principles of Applied Animal Andrology

PETER CHENOWETH

Introduction

Animal andrology has emerged as a scientific discipline only relatively recently. However, it draws deeply from the wealth of knowledge contained in the classic scientific disciplines of anatomy, physiology, pathology, and genetics, as well as from rapidly burgeoning fields such as molecular and cell biology, genomics, proteomics, and metabolomics. The impressive breadth of knowledge and interests which are today recognized as being within the animal andrology spectrum are witnessed by the topics contained herein.

Animal andrology has its own basis of underlying concepts and principles, including terminology, definitions, procedures, diagnostics, and prognostics, that collectively provide the necessary cytoskeleton for ensuring scientific and clinical commonality and consistency. Examples of a number of abbreviations and acronyms used in animal andrology are provided in the Appendix 1.1.

As the scientific foundations of animal andrology have been described previously in Animal Andrology: Theories and Practices (Chenoweth and Lorton, 2014), this manual aims to complement this more scientifically focused tome by providing practical, hands-on information for many animal andrology procedures. Emphasis is placed on two major aspects of animal andrology: (i) the assessment and management of breeding males; and (ii) the laboratory handling, evaluation, and processing of semen for artificial insemination. In turn, the adoption of good laboratory practices (GLPs) that result in a consistent, quality product is closely linked with considerations of quality control (QC) and quality assurance (QA).

The Male Mission

The starting point for any evaluation of an animal, product, or procedure is to clarify its intended purpose. Here, the purpose, or ‘mission’, of males in domestic animal breeding has been described as the deposition of fertile sperm at the appropriate female site at the optimal time for fertilization to occur. However, although this might describe ‘success’ in companion animal breeding, it is inadequate for males in herds or flocks where production goals dictate more quantitative assessments. For example, considerations for range-type beef cattle fertility include not only pregnancy rate (or percent females pregnant), but also the time frame in which this occurs. In swine, pregnancy rate and timing are important, as well as litter size.

Today, male fertility considerations in domestic animals extend far beyond those which occur for natural breeding. Artificial insemination (AI) using liquid or frozen semen is widely used to achieve genetic progress in herds and flocks. Implementing this technology requires a number of additional considerations for ensuring acceptable semen fertility, and these considerations multiply when cryopreserved semen is used in conjunction with estrous synchronization, in-vitro fertilization (IVF), and/or other assisted reproductive techniques (ART). Along with greater sophistication of breeding technologies comes greater complexity of component tasks and less allowance for imprecision or incompetence. Collectively, these considerations bolster the case for appropriate education and training of animal breeding personnel. The current apparent, and growing, shortfall in relevant education and training has been a major incentive for this manual, in which an attempt is made to provide a continuum between essential male reproductive evaluation and those reproductive technologies which are reliant upon fertile male gametes.

The fundamentals, however, commence with the capability of the male to procreate which is assessed, at least initially, by means of an andrological evaluation.

Andrological Evaluation

Although tacitly accepted as an essential aspect of domestic animal propagation, male fertility has historically received much less scientific attention than in females. Despite early Russian and Cornell University studies that created awareness of its significance, it took the widespread acceptance of cattle AI to create an upsurge in relevant studies, which continues today. Milestones included the early development of the artificial vagina in Italy, Swedish bull studies of Lagerlöf and Bane, the development of effective semen extenders, the first successful cryopreservation of bovine semen and development of a safe and effective electro-ejaculator (EEJ) by Marden in the mid-1950s. The latter allowed routine semen assessments to occur with unhandled bulls, particularly in the beef cattle industry and also with untrained small ruminants. More latterly, EEJ has been widely employed with males of species which are undomesticated and/or endangered. With reference to bulls, such developments were the catalyst for the formation of the Rocky Mountain Society for the Study of Bull Breeding Soundness (RMSSBBS) in 1954, which subsequently became the Society for Theriogenology with a much wider mandate. Today, the momentum continues, with the benefits of powerful new tools such as genomics, proteomics, and metabolomics.

Many of these new technologies require sophisticated equipment and focused training which constrains their routine applications in animal breeding, especially in less developed countries. However, their exploitation will undoubtedly increase with mounting pressures to optimize animal reproduction. These pressures vary from direct individual economic incentives to global human needs for food, fiber, sport, leisure, and companionship. Keeping pace with both need and demand relies upon appropriate levels of education and training in animal reproduction methods and applications. Unfortunately, opportunities for obtaining knowledge and expertise in applied animal reproduction (including andrology) are lacking, and apparently decreasing, not only in the developing world but in more affluent countries as well (Chenoweth, 2012).

Andrological or breeding soundness evaluations (BSE) are conducted for a variety of reasons including pre-sale and pre-mating, or to detect and investigate fertility problems. The term breeding soundness applies to an individual which is deemed fit for purpose, i.e. capable of being reasonably fertile under normal mating conditions, after fulfilling the prescribed examinations and tests. Although this term applies to both genders, it is herein employed within the male context only.

Although routine male BSE differ with species and geography, they should generally include the following:

•animal identification;

•relevant history;

•physical examination;

•reproductive examination; and

•semen collection and examination.

Other procedures such as sampling for reproductive infectious disease(s) and examination for sexual interest and capability may be included as requested or desired.

Animal andrological evaluation in practice

Animal andrological evaluations can vary greatly in complexity and cost. In production animals, they have evolved to become a relatively quick, simple, and economic procedure, i.e. the BSE, in which individuals are screened for their potential reproductive capabilities. The findings are often expressed as ‘satisfactory’, ‘unsatisfactory’, or ‘indeterminat...

Table of contents

• Cover
• Title page
• Copyright
• Contents
• Preface
• List of Contributors
• Part 1: General Information
• Part 2: Species
• Index
• Back Cover