Principles and Clinical Uses of Real-Time Ultrasonography in Female Swine Reproduction

Abstract

Simply SummaryReal-time ultrasonography (RTU) has become an essential diagnostic value when assessing female swine reproduction in either individual or groups of animals. Diagnostic application of RTU is applied throughout most stages of production, including gilt development, breeding, gestation and farrowing. Along with its most common use in on-farm assessment of pregnancy status, RTU is also used to troubleshoot disruptions in reproductive performance such as delayed puberty, prolonged wean-to-estrus interval, absence of post-weaning estrus, decreased conception and farrowing rates, vulval discharge, peripartum and puerperal disorders. This review aims to provide an overview on principles and clinical uses of RTU in female reproduction on commercial swine farms.AbstractWithin the past 30 years, through ongoing technology and portability developments, real-time (b-mode) ultrasonography (RTU) has increasingly become a valuable diagnostic tool in assessing the female reproductive tract in swine. Initially applied in swine production to visually determine pregnancy status, RTU use has expanded to include assessment of the peri-pubertal and mature non-pregnant females as well. Transabdominal and transrectal modalities to visualizing the reproductive tract in swine have been reported with the transabdominal approach more common due to the fact of its ease of accessibility, animal/personnel safety, and reduced time to perform. Adjustable frequency transducers are preferred as they allow optimization of image quality at various depths. If a single transducer frequency must be selected, a 5 MHz probe provides the best versatility for visualizing the reproductive tract in swine. Other basic requirements for ultrasound equipment which will be used on commercial swine farms include being light weight and easy to handle, readily cleanable and disinfectable, long battery-life, and good durability. When using RTU for pregnancy determination, diagnosis is based upon a combination of the animal’s breeding records, the presence of embryonic fluid, and, depending upon gestational stage, fetal structures. If RTU is used as a diagnostic tool in assessing reproductive problems in an individual or a group of animals, sonographic evaluation of both the uterus and ovaries is performed. Tissues are delineated and assessed based upon their echogenicity, echotexture, and size. Uses of RTU in clinical practice may include assessment of delayed puberty, prolonged wean-to-estrus interval, absence of post-weaning estrus, herd disruptions in conception and farrowing rates, vulval discharge, peripartum and puerperal disorders. This review aims to provide an overview on principles and clinical uses of RTU with respect to application to address female reproductive performance issues in commercial swine operations.

Tools and Protocols for Managing Hyperprolific Sows at Parturition: Optimizing Piglet Survival and Sows’ Reproductive Health

“…Whenever the abovementioned criteria are fulfilled, an obstetrical examination needs to be performed. An obstetric examination includes palpation and ultrasonography of the birth canal [12,59]. Palpation of the birth canal should always occur through the rectum and not through the vagina.…”

“…Ultrasonography can be used to determine whether farrowing is over or if the sow has retained piglets [59] or placentae [60] (Figure 2). Table 5.…”

“…Besides prolonged parturition, obstetrical intervention, and the birth of more than one dead piglet, also retained placentae is a risk factor for endometritis [3]. For both, endometritis and retained placentae, ultrasonography is considered the best tool for diagnosis [3,59,78,87]. Examination of uterine structures currently utilizes three criteria: fluid echogenicity, echotexture, and size [59,87].…”

“…For both, endometritis and retained placentae, ultrasonography is considered the best tool for diagnosis [3,59,78,87]. Examination of uterine structures currently utilizes three criteria: fluid echogenicity, echotexture, and size [59,87]. Changes in echotexture are a reflection of changes in the endometrial edema.…”

“…Changes in echotexture are a reflection of changes in the endometrial edema. Increased echotexture and any fluid echogenicity must be considered abnormal and indicative of an exudative inflammation of an acute or acute-chronic type [59,87]. Fluid echogenicity is often associated with uterine edema and therefore increased echotexture and size of uterine cross-sections [3].…”