ULTRASONOGRAPHIC OBSERVATION OF POSTPARTUM UTERINE INVOLUTION IN THE POLISH LONGWOOL SHEEP VARIETY KAMIENIECKA

Sławomir Zduńczyk, Stanisław Milewski, Wojciech Barański, Tomasz Janowski, Wiesław Szczepański, Andrzej Raś, Andrzej Jurczak

ABSTRACT

The study was carried out on 22 winter–lambing, suckling Polish Longwool sheep variety Kamieniecka. The completion of uterine involution was determined by means of transrectal ultrasonography. Parameters for the evaluation of uterine involution were the transversal diameter and the presence of uterine lumen. The uterine involution was finished in 5 (22.7 %) ewes till day 25 p.p., in 12 (54.5 %) till day 30 p.p. and in 18 (81.8 %) till day 35 p.p. The results of the present study confirmed that ultrasonography is a useful and reliable method to observe the uterine involution in sheep and showed that the uterine involution in most winter-lambing Polish Longwoll sheep variety Kamieniecka finishes untill day 35 p.p.

Key words: sheep, uterine involution, ultrasonography..

INTRODUCTION

During the post-partum period the sheep should re-establish the functionality of the reproductive system and prepare for a new pregnancy. This includes uterine involution and resumption of cyclic ovarian activity. The finishing of uterine involution is a prerequisite to the maintenance of pregnancy. The time estimated for the completion of uterine involution in sheep varies between 17 and 30 days [2,8,10,11]. Many factors, such as dystocia, retention of foetal membranes, suckling, breed and season are implicated for the course of uterine involution [1,10,11].

There are no informations about the puerperal period in the Polish Longwool sheep variety Kamieniecka.

The evaluation of uterine involution based only on clinical axamination is insufficient, because the uterus in sheep can not be palpated per rectum. Recently, the use of ultrasonography for the control of the uterine involution in sheep has been described [6].

The aim of this study was to determine the end of uterine involution in Polish Longwool sheep variety Kamieniecka by means of ultrasonography.

MATERIAL AND METHODS

The study was carried out on 22 suckling Polish Longwool sheep variety Kamieniecka at the age of three to six years. They were spontaneously lambing in January or February. The sheep were fed with hay and concentrate.

A sonographic examination was carried out on day 25, 30 and 35 post-partum (p.p.) by using a real time, B-mode ultrasound scanner (Pie Medical Scanner 200) with a linear-array transducer of 5.0 MHz. Sonographic pictures were documented by a video graphic printer (Mitsubishi P67E). The animals were examined in standing position by the transrectal ultrasound scanning. The probe fixed to an extension rod was inserted into the rectum. For scanning of the uterus, the probe was moved approximately 60° to each side around its longitudinal axis. Parameters for the evaluation of the end of uterine involution were the transversal diameter of uterine horns of £ 2 cm and the lack of contents in the uterine cavity [1].

Additionally the sheep were examined by vaginoscopy and the presence of the postpartum discharges were registered.

RESULTS

The postpartum uterus was well identified by its typical ultrasonographic pattern. The end of uterine involution was characterised by an small cross-sectional diameter of uterine horns and absence of lochia in uterus (Fig. 1). The postpartum discharges were not more present in the vagina. If uterine involution was not finished the transversal diameter of uterine horn was above 2 cm and lochia were accumulated within the lumen (Fig. 2). They could be funded also in vagina.

The uterine involution was finished in 5 (22.7 %) ewes till day 25 p.p., in 12 (54.5 %) till day 30 p.p. and in 18 (81.8 %) till day 35 p.p. (Fig. 3).

In the present study almost 82 % of investigated ewes finished uterine involution till day 35 p.p. This corresponded to a study of some authors [8, 10, 9] that determined the end of uterine involution after 30 days p.p. In contrary, other authors [5,6,11] observed the end of uterine involution approximately at day 20 p.p. The variability regarding the time required for a complete uterine involution may result from differences in breed, period of lambing and suckling.

The clinical investigation of uterine involution in sheep is difficult because the uterus can not be examinated by rectal or abdominal palpation and uterine discharges ceases shortly after parturition due to the closure of the cervix. Uterine involution in sheep has been asessed histologically [3,7,13], macroscopically at slaughter [2,3] and by means of radio-opaque markers and radiography [12]. In contrast to these methods B-mode real time ultrasound allows the noninvasive examination of uterus in sheep. The transrectal scanning is more reliable method than the transcutaneus. The pilot study showed that it was often not possible to observe the uterus by transcutaneus scanning because to great distance of uterine horns to abdominal wall. The filled rumen limited also the assessment of the uterus using transabdominal scanning.

Our study confirmed that ultrasonography is a useful and reliable technique to observe the uterine involution in sheep [6].

The results of the present study showed that the uterine involution in most winter-lambing Polish Longwoll sheep variety Kamieniecka finishes untill day 35 p.p.

REFERENCES

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