Morphology of the Genital Tract and Serum Progesterone Concentrations in Cows Within 45 Days after Parturition

Abstract

Bmo, 60, 1991: 181-192.To ascertain serum progesterone concentrations in cows (Bohemian Pied x Holstein-Friesian) under standard husbandry practices clinical observations were made and blood samples from v. jugularis were taken in five-day intervals Within 45 days after parturition, and a post-mortem macroscopic examination of reproductive organs of a selected group of cows were carried out within 35 days post partum. We clinically demonstrated the closing of the orificii cervicis internum and externum by day 15-20 and day 30 post partum, respectively. The uterus continuously retracted into the pelvis within 20 days post partum and its wall regained characteristics of a nongravid uterus by day 10. Ovaries were palpable from day 5 -10 post partum and from day 35 usually exhibited a typical finding of a sexual cycle. Macroscopic examination showed that the uterus was reducing its size markedly until day 10, and less markedly until day 20-25 post partum. Its mass decreased from 10:1: 1.6 on the day of parturition to 2.3:1:0.9 kg on day 10 and to 0.9 ± 0.0 on day 20 post partum.The average mass of ovaries contralateral to the previously pregnant uterine hom gradually grew from 3.7 :I: 0.91 g on day 10 post partum to 6.8 :I: 3.06 g on day 20, when it was heavier than ipsilateral ovaries (6.3 ± 2.92 g). The number of ovarian follicles 1 to 3 mm in size grew markedly between day 5 and 15 post partum, From day 5 post partum, ovaries exhibited increased numbers of follicles exceeding 3 mm in size. Slightly increased serum progesterone concentrations (0.6 -1.0 ng/ml) were found most frequently on days 20 and 25 post partum. Later, the number of cows with a concentration of 1.1 or more increased gradually. Post-partum period, ut~, waries, follicles, serum progesterone, cowAn early completion of post-partum structural and functional changes of reproductive organs in cows together with the onset of a cyclic ovarian activity is of paramount importance for achieving a continuous intensive reproduction in cattle. The opinions on when uterine involution in cows is completed are far from unanimous, the periods mentioned ranging between 16 and 60 days post partum (Rasbech 1950; Sipilov 1958, Schultz andGrunert 1959;Gier and Marion 1968; Morrow et a1. 1969;Studer and Morrow 1981;Hafez 1987;Kudlac and Elecko 1987;Arthur et al. 1989) Besides a large number of endogenous and exogenous factors inftuencing the involution, the differences also result from the fact that different criteria and more or less accurate indices are used. For similar reasons, the data on the onset of the cyclic ovarian activity exhibit considerable variations. Simultaneous growth, atresia and luteinization of follicles in the post-partum period leads, by a mechanism which has not yet been quite elucidated, to the selection of a dominant preovulatory follicle, ovulation and the appearance of the first cyclic corpus

Ovarian Activity in Ultrasound Image and Milk Progesterone Concentration in Postpartum Dairy Cows

“…average value 27.74 days is stated by Kudhic and Vlcek (1970) but the term is comparable with the results of other authors (Morrow et al 1969;Garcia and Larson 1982;Duby et al 1985;Savio et al 1990). We discovered a shorter length of the 1st postpartum seXual cycle in cows which ovulated before day 20 post partum than in cows which ovulated later.…”

“…Various quality and lifespan of the first postpartum luteal structures are cited by Lauderdaleet a1. (1968), Duby et al (1985), Rutter and Randel (1985). Development of follicles influence the quality and lifespan of following luteal structures (Smith, 1986, Inskeep et al, 1988.…”

“…Some of the 1st postpartum luteal structures in cows having a short sexual cycle represented in ultrasound image corpus hemorhagicum (diameter < 20 mm, low echogenity of luteal tissue, sometimes cavity) throughout its lifespan. Shorter 1st postpartum sexual cycles, the relation of the length of the 1st sexual cycle to the term of the 1st postpartum ovulation, and different quality of the 1st postpartum corpus luteum are described by Morrow et al (1966), Lauderdale et al (1968), Garcia and Larsson (1982), Duby et al (1985), Rutter and Randel (1985), Schallenberger (1985). Slightly higher levels of serum progesterone (0.6-• 1.0 ng/mI) are often accompanied by small atypical luteal structures in ovaries at day 20-25 post partum (Doleiel et al 1991).…”

Determining Pregnancy From Blubber in Three Species of Delphinids

“…Mammalian adipose tissue, like that found in blubber, is known to accumulate steroid hormones (Dolezel et al 1991), and the concentrations of these hormones have been associated with different pregnancy states (Hamudikuwanda et al 1996). The lipophilic steroids amass in high concentrations in adipose tissue because they can passively diffuse from capillaries into this mostly lipid environment (Deslypere et al 1985, Mead et al 1986), where metabolic and physiological processes that would break down or remove the steroids are slow relative to those occurring in the blood.…”

Uso de gordura subcutânea como matriz biológica na dosagem de esteroides sexuais em baleias jubarte (Megaptera novaeangliae)

“…Uma alternativa para superar estas dificuldades seria a dosagem de hormônios acumulados na camada de gordura por meio da colheita de amostras de animas vivos por biópsia. É sabido que os hormônios esteroides têm uma afinidade com o tecido adiposo e tendem a se acumular na camada de gordura do animal (DOLEZEL et al, 1991). Os esteroides lipofílicos acumulam-se em grandes concentrações no tecido adiposo porque podem passivamente difundir dos capilares a este meio mais lipidinoso (DESLYPERE et al, 1985) onde os processos metabólicos e fisiológicos que os quebram ou removem são relativamente mais lentos do que aqueles que ocorrem no sangue.…”